WorldWideScience

Sample records for voltage silicon switching

  1. Optically initiated silicon carbide high voltage switch

    Science.gov (United States)

    Caporaso, George J.; Sampayan, Stephen E.; Sullivan, James S.; Sanders; David M.

    2011-02-22

    An improved photoconductive switch having a SiC or other wide band gap substrate material, such as GaAs and field-grading liners composed of preferably SiN formed on the substrate adjacent the electrode perimeters or adjacent the substrate perimeters for grading the electric fields.

  2. Simulations and Silicon Wafer Compatibility of a Voltage-Controlled Optical Switch Using ITO/NbOx

    Science.gov (United States)

    Burghardt, Kevin

    The story of optics and processing has always been on of silicon devices making strides faster and cheaper than optics. The idea of creating optical switches has been generally relegated to academic exercises or niche markets. This research takes a view of optical processing that is complimentary to silicon. Silicon wafers produce extremely dense, high quality devices but producing truly 3D integrated circuits has been a challenge. It would be advantageous to not need to bond wafers to create a 3D active structure. An argument for an optical switch that has a simple structure and uses industry established fabrication methods is given. The proposed switch uses the material indium tin oxide nanoparticles in niobum oxide glass (ITO/NbOx) as the active layer. The transmittance through this material is proportional to the electric field applied to it meaning the structure of a capacitor could be used to control it. It uses a metal for one plate of the capacitor and the ITO/NbOx as the other plate with the light running through ITO/NbO x plate. Each of the plates are separated from one another and surrounded by a dielectric material. Simulations show that silicon dioxide (SiO 2) can be used effectively to turn the ITO/NbOx into a light guide with a transmittance controllable using an applied voltage and that the proposed structure can be created using industry established wafer fabrication processes.

  3. Accurate Switched-Voltage voltage averaging circuit

    OpenAIRE

    金光, 一幸; 松本, 寛樹

    2006-01-01

    Abstract ###This paper proposes an accurate Switched-Voltage (SV) voltage averaging circuit. It is presented ###to compensated for NMOS missmatch error at MOS differential type voltage averaging circuit. ###The proposed circuit consists of a voltage averaging and a SV sample/hold (S/H) circuit. It can ###operate using nonoverlapping three phase clocks. Performance of this circuit is verified by PSpice ###simulations.

  4. Bootstrapped Low-Voltage Analog Switches

    DEFF Research Database (Denmark)

    Steensgaard-Madsen, Jesper

    1999-01-01

    Novel low-voltage constant-impedance analog switch circuits are proposed. The switch element is a single MOSFET, and constant-impedance operation is obtained using simple circuits to adjust the gate and bulk voltages relative to the switched signal. Low-voltage (1-volt) operation is made feasible...

  5. Low-Voltage Switched-Capacitor Circuits

    DEFF Research Database (Denmark)

    Bidari, E.; Keskin, M.; Maloberti, F.

    1999-01-01

    Switched-capacitor stages are described which can function with very low (typically 1 V) supply voltages, without using voltage boosting or switched op-amps. Simulations indicate that high performance may be achieved using these circuits in filter or data converter applications.......Switched-capacitor stages are described which can function with very low (typically 1 V) supply voltages, without using voltage boosting or switched op-amps. Simulations indicate that high performance may be achieved using these circuits in filter or data converter applications....

  6. Transient voltage sharing in series-coupled high voltage switches

    Directory of Open Access Journals (Sweden)

    Editorial Office

    1992-07-01

    Full Text Available For switching voltages in excess of the maximum blocking voltage of a switching element (for example, thyristor, MOSFET or bipolar transistor such elements are often coupled in series - and additional circuitry has to be provided to ensure equal voltage sharing. Between each such series element and system ground there is a certain parasitic capacitance that may draw a significant current during high-speed voltage transients. The "open" switch is modelled as a ladder network. Analy­sis reveals an exponential progression in the distribution of the applied voltage across the elements. Overstressing thus oc­curs in some of the elements at levels of the total voltage that are significantly below the design value. This difficulty is overcome by grading the voltage sharing circuitry, coupled in parallel with each element, in a prescribed manner, as set out here.

  7. Improved Lifetime High Voltage Switch Electrode.

    Science.gov (United States)

    2014-09-26

    capabilities of spark switches (e.g., saturable magnetic reactors, ignitions, and high power vacuum tubes), none has the combined high voltage, high...series impedance of the switch . Additionally, the eroded material may be deposited on internal insulators , thereby inducing pretriggering and erratic...of dry air, a typical spark switch insulating gas. -7- ENERGETIC IONS FROM ION IMPLANTER 0 0 0 0 -0 0 00000 0 0 oSUBSTRATE 0 - 0 o 0 SAMPLE= ’ 0• 0 U 0

  8. Resistive switches and memories from silicon oxide.

    Science.gov (United States)

    Yao, Jun; Sun, Zhengzong; Zhong, Lin; Natelson, Douglas; Tour, James M

    2010-10-13

    Because of its excellent dielectric properties, silicon oxide (SiO(x)) has long been used and considered as a passive, insulating component in the construction of electronic devices. In contrast, here we demonstrate resistive switches and memories that use SiO(x) as the sole active material and can be implemented in entirely metal-free embodiments. Through cross-sectional transmission electron microscopy, we determine that the switching takes place through the voltage-driven formation and modification of silicon (Si) nanocrystals (NCs) embedded in the SiO(x) matrix, with SiO(x) itself also serving as the source of the formation of this Si pathway. The small sizes of the Si NCs (d ∼ 5 nm) suggest that scaling to ultrasmall domains could be feasible. Meanwhile, the switch also shows robust nonvolatile properties, high ON/OFF ratios (>10(5)), fast switching (sub-100-ns), and good endurance (10(4) write-erase cycles). These properties in a SiO(x)-based material composition showcase its potentials in constructing memory or logic devices that are fully CMOS compatible.

  9. Mechanism of single atom switch on silicon

    DEFF Research Database (Denmark)

    Quaade, Ulrich; Stokbro, Kurt; Thirstrup, C.

    1998-01-01

    We demonstrate single atom switch on silicon which operates by displacement of a hydrogen atom on the silicon (100) surface at room temperature. We find two principal effects by which the switch is controlled: a pronounced maximum of the switching probability as function of sample bias...

  10. Analysis of System Wide Distortion in an Integrated Power System Utilizing a High Voltage DC Bus and Silicon Carbide Power Devices

    Science.gov (United States)

    2007-06-01

    concentrated on the power supplied to a propulsion motor driven by an inverter with simulated silicon carbide switches. Theoretically, silicon ... carbide switches have the advantage of being able to withstand a very large blocking voltage and carry very large forward currents. Silicon carbide switches...are also very efficient due to their quick rise and fall times. Since silicon carbide switches can withstand high voltage differentials and switch

  11. High voltage photoconductive switch package

    Energy Technology Data Exchange (ETDEWEB)

    Caporaso, George J.

    2016-11-22

    A photoconductive switch having a wide bandgap material substrate between opposing electrodes, and a doped dielectric filler that is in contact with both the electrodes and the substrate at the triple point. The dielectric filler material is doped with a conductive material to make it partially or completely conducting, to minimize the field enhancement near the triple point both when the substrate is not conducting in the "off" state and when the substrate is rendered conducting by radiation in the "on" state.

  12. Design and Fabrication of Micromechanical Optical Switches Based on the Low Applied Voltage

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A micromechanical optical switch driven by electrostatic was fabricated with (100) silicon and tilted 2.5° (111) silicon. The pull-in voltage is 13.2V, the insertion loss is less than 1.4dB, the crosstalk is less than -50 dB.

  13. Isolated Fast High-Voltage Switching Circuit

    Science.gov (United States)

    Rizzi, Anthony

    1992-01-01

    Electrically isolated switching circuit supplies pulses at potentials up to 6.5 kV and currents up to 6.5 A, lasting as long as few microseconds. Turn-on time about 40 ns; turn-off time about 3 microseconds. Electrically isolated from control circuitry by means of fiber-optic signal coupling and isolated power supply. Electrical isolation protects both technician and equipment. This and similar circuits useful in such industrial and scientific applications as high-voltage, high-frequency test equipment; electrostatic-discharge test equipment; plasma-laboratory instrumentation; spark chambers; and electromagnetic-interference test equipment.

  14. High voltage switches having one or more floating conductor layers

    Energy Technology Data Exchange (ETDEWEB)

    Werne, Roger W.; Sampayan, Stephen; Harris, John Richardson

    2015-11-24

    This patent document discloses high voltage switches that include one or more electrically floating conductor layers that are isolated from one another in the dielectric medium between the top and bottom switch electrodes. The presence of the one or more electrically floating conductor layers between the top and bottom switch electrodes allow the dielectric medium between the top and bottom switch electrodes to exhibit a higher breakdown voltage than the breakdown voltage when the one or more electrically floating conductor layers are not present between the top and bottom switch electrodes. This increased breakdown voltage in the presence of one or more electrically floating conductor layers in a dielectric medium enables the switch to supply a higher voltage for various high voltage circuits and electric systems.

  15. Zero-voltage switching technique in dc/dc converters

    Science.gov (United States)

    Liu, Kwang-Hwa; Lee, Fred C. Y.

    1990-07-01

    A novel resonant switch operating under the principle of zero-voltage switching is presented. In contrast to the zero-current switching, this technique eliminates the switching loss and dv/dt noise due to the discharging of MOSFET junction capacitances and the reverse recovery of diodes, and enables the converters to operate at high frequencies. A dc analysis of the converter is carried out. The duality relationship between the zero-current switching technique and the zero-voltage switching technique is derived. The two techniques are compared using an example showing the duality between a current-mode quasi-resonant Buck converter and a voltage-mode quasi-resonant boost converter. A 5-MHz 50 V to 5 V flyback converter employing the zero-voltage switching technique has been implemented. The circuit contains the smallest number of components possible, and yet maintains high efficiency at high switching frequency.

  16. Design & Implementation of Zero Voltage Switching Buck Converter

    Directory of Open Access Journals (Sweden)

    A.Suresh Kumar

    2014-09-01

    Full Text Available Zero voltage switching (ZVS buck converter is more preferable over hard switched buck converter for low power, high frequency DC-DC conversion applications. In Zero voltage switching converter, turn on & turn off of a switch occurs at zero voltage that results in lower switching losses. In this converter soft switching is achieved by using resonant components. The optimal values of resonant components are determined by using electric functions derived from circuit configuration. This type of soft switched resonant converter offers very low electromagnetic interference (EMI.This study presents the circuit configuration with least components to realize highly efficient zero voltage switching resonant converter. It’s feasibility is confirmed with the developed proto type model and experimental results are verified.

  17. A new Zero-Voltage-Transition PWM switching cell

    Energy Technology Data Exchange (ETDEWEB)

    Grigore, V. [Electronics and Telecommunications Faculty `Politebuica` University Bucharest (Romania); Kyyrae, J. [Helsinki University of Technology, Otaniemi (Finland): Institute of Intelligent Power Electronics

    1997-12-31

    In this paper a new Zero-Voltage-Transition (ZVT) PWM switching cell is presented. The proposed switching cell is composed of the normal hard-switched PWM cell (consisting of one active switch and one passive switch), plus an auxiliary circuit (consisting of one active switch and some reactive components). The auxiliary circuit is inactive during the ON and OFF intervals of the switches in the normal PWM switch. However, the transitions between the two states are controlled by the auxiliary circuit. Prior to turn-on, the voltage across the active switch in the PWM cell is forced to zero, thus the turn-on losses of the active switch are practically eliminated. At turn-off the auxiliary circuit behaves like a non-dissipative passive snubber reducing the turn-off losses to a great extent. Zero-Voltage-Transition switching technique almost eliminates switching losses. The active switch operates under ZVT conditions, the passive switch (diode) has a controlled reverse recovery, and the switch in the auxiliary circuit operates under Zero-Current-Switching (ZCS) conditions. (orig.) 6 refs.

  18. Valley blockade quantum switching in Silicon nanostructures.

    Science.gov (United States)

    Prati, Enrico

    2011-10-01

    In analogy to the Coulomb and the Pauli spin blockade, based on the electrostatic repulsion and the Pauli exclusion principle respectively, the concept of valley blockade in Silicon nanostructures is explored. The valley parity operator is defined. Valley blockade is determined by the parity conservation of valley composition eigenvectors in quantum transport. A Silicon quantum changeover switch based on a triple of donor quantum dots capable to separate electrons having opposite valley parity by virtue of the valley parity conservation is proposed. The quantum changeover switch represents a novel kind of hybrid quantum based classical logic device.

  19. Advances in high voltage power switching with GTOs

    Energy Technology Data Exchange (ETDEWEB)

    Podlesak, T.F. (US Army Electronic Technology and Devices Lab., Fort Monmouth, NJ (US)); McMurray, J.A. (Vitronics, Eatontown, NJ (US)); Carter, J.L.

    1990-12-01

    The control of high voltage at high power, particularly opening switches, has been difficult in the past. Using gate turnoff thyristors (GTOs) arranged in series enables large currents to be switched at high voltage. A high voltage opening switch has been successfully demonstrated in our laboratory. This switch uses GTOs in series and successfully operates at voltages higher than the rated voltage of the individual devices. It is believed that this is the first time this has been successfully demonstrated, in that GTOs have been operated in series before, but always in a manner as to not exceed the voltage capability of the individual devices. In short, the devices have not worked together, sharing the voltage, but one device has been operated using several backup devices. Of particular interest is how well the individual devices share the voltage applied to them. Equal voltage sharing between devices is absolutely essential, in order to not exceed the voltage rating of any of the devices in the series chain. This is accomplished at high (microsecond) switching speeds. Thus, the system is useful for high frequency applications as well as high power, making for a flexible circuit system element. This paper reports on this demonstration system that is rated at 5 KV and uses 1 KV devices. A larger 24 KV system is under design and will use 4.5 KV devices. In order to design the 24 KV switch, the safe operating area of the large devices must be known thoroughly.

  20. High Voltage, Fast-Switching Module for Active Control of Magnetic Fields and Edge Plasma Currents

    Science.gov (United States)

    Ziemba, Timothy; Miller, Kenneth; Prager, James; Slobodov, Ilia

    2016-10-01

    Fast, reliable, real-time control of plasma is critical to the success of magnetic fusion science. High voltage and current supplies are needed to mitigate instabilities in all experiments as well as disruption events in large scale tokamaks for steady-state operation. Silicon carbide (SiC) MOSFETs offer many advantages over IGBTs including lower drive energy requirements, lower conduction and switching losses, and higher switching frequency capabilities; however, these devices are limited to 1.2-1.7 kV devices. As fusion enters the long-pulse and burning plasma eras, efficiency of power switching will be important. Eagle Harbor Technologies (EHT), Inc. developing a high voltage SiC MOSFET module that operates at 10 kV. This switch module utilizes EHT gate drive technology, which has demonstrated the ability to increase SiC MOSFET switching efficiency. The module will allow more rapid development of high voltage switching power supplies at lower cost necessary for the next generation of fast plasma feedback and control. EHT is partnering with the High Beta Tokamak group at Columbia to develop detailed high voltage module specifications, to ensure that the final product meets the needs of the fusion science community.

  1. New zero voltage switching DC converter with flying capacitors

    Science.gov (United States)

    Lin, Bor-Ren; Shiau, Tung-Yuan

    2016-04-01

    A new soft switching converter is presented for medium power applications. Two full-bridge converters are connected in series at high voltage side in order to limit the voltage stress of power switches at Vin/2. Therefore, power metal-oxide-semiconductor field-effect transistors (MOSFETs) with 600 V voltage rating can be adopted for 1200 V input voltage applications. In order to balance two input split capacitor voltages in every switching cycle, two flying capacitors are connected on the AC side of two full-bridge converters. Phase-shift pulse-width modulation (PS-PWM) is adopted to regulate the output voltage. Based on the resonant behaviour by the output capacitance of MOSFETs and the resonant inductance, active MOSFETs can be turned on under zero voltage switching (ZVS) during the transition interval. Thus, the switching losses of power MOSFETs are reduced. Two full-bridge converters are used in the proposed circuit to share load current and reduce the current stress of passive and active components. The circuit analysis and design example of the prototype circuit are provided in detail and the performance of the proposed converter is verified by the experiments.

  2. Organolead Halide Perovskites for Low Operating Voltage Multilevel Resistive Switching.

    Science.gov (United States)

    Choi, Jaeho; Park, Sunghak; Lee, Joohee; Hong, Kootak; Kim, Do-Hong; Moon, Cheon Woo; Park, Gyeong Do; Suh, Junmin; Hwang, Jinyeon; Kim, Soo Young; Jung, Hyun Suk; Park, Nam-Gyu; Han, Seungwu; Nam, Ki Tae; Jang, Ho Won

    2016-08-01

    Organolead halide perovskites are used for low-operating-voltage multilevel resistive switching. Ag/CH3 NH3 PbI3 /Pt cells exhibit electroforming-free resistive switching at an electric field of 3.25 × 10(3) V cm(-1) for four distinguishable ON-state resistance levels. The migration of iodine interstitials and vacancies with low activation energies is responsible for the low-electric-field resistive switching via filament formation and annihilation.

  3. Low voltage drop plasma switch for inverter and modulator applications

    Science.gov (United States)

    Goebel, D. M.; Poeschel, R. L.; Schumacher, R. W.

    1993-08-01

    A low forward voltage drop plasma switch has been developed for high-efficiency inverter and modulator applications. The switch, called the HOLLOTRON, is based on a grid-controlled, thermionic hollow-cathode discharge. A low forward voltage drop (10-20 V) is achieved by operating the hollow-cathode discharge in a static gas pressure of xenon. The dense plasma generated in the Ba-oxide dispenser hollow cathode is spread over a relatively large control grid area by a diverging magnetic field superimposed on the discharge. Interruption of the discharge current at high current densities (≳4 A/cm2) over the grid area is achieved by biasing the control grid sufficiently negative with respect to the plasma. The HOLLOTRON switch has demonstrated voltage stand-off of up to 20 kV, switching times of ≤0.3 μs, and pulse repetition frequencies of 20 kHz at 50% duty.

  4. A new Zero Voltage Switching three-level NPC inverter

    DEFF Research Database (Denmark)

    He, Ning; Chen, Yenan; Xu, Dehong

    2015-01-01

    A novel Zero Voltage Switching (ZVS) three-level NPC inverter topology using a new ZVS Space Vector Modulation (SVM) scheme is proposed. A detailed operation analysis of ZVS three-level NPC inverter is given. The ZVS condition of the proposed ZVS inverter is derived and it can be achieved of all...... switches in the proposed inverter, which include both the main switches and the auxiliary switches. The design of resonant circuits parameters is also provided. Finally the proposed circuit and ZVS SVM scheme are verified by experimental results and demonstrate a superior performance....

  5. Low-voltage switched-current delta-sigma modulator

    Science.gov (United States)

    Tan, Nianxiong; Eriksson, Sven

    1995-05-01

    This paper presents the design of a fully differential switched-current delta-sigma modulator using a single 3.3-V power-supply voltage. At system level, we tailor the modulator structure considering the similarity and difference of switched-capacitor and switched-current realizations. At circuit level, we propose a new switched-current memory cell and integrator with improved common mode feedback, without which low power-supply-voltage operation would not be possible. The whole modulator was implemented in a 0.8- micron double-metal digital CMOS process. It occupies an active area of 0.53 x 0.48 mm(sup 2) and consumes a current of 0.6 mA from a single 3.3-V power supply. The measured dynamic range is over 10 b.

  6. Implementation strategy for soft switching PFC with low output voltage

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper proposes a novel implementation strategy for soft switching PFC whose circuit is simple and can achieve low voltage output directly. The main circuit adopts current mode full-bridge converter and all the power switches can realize ZCS or ZVS in the way of phase-shifted control, using the leakage inductance of the transformer, the junction capacitor of the switches and the stored energy of the output capacitor. The problems such as the function of phase-shifted link in control circuit, the implementation conditions of soft switching and bias restrained are analyzed. The adoption of constant frequency PWM control makes the design of the input and output filter link and the high frequency transformer simple. The transformation ratio regulation so as to achieve low voltage output and electrical insulation can be realized by using high frequency transformer.

  7. Low Actuating Voltage Spring-Free RF MEMS SPDT Switch

    Directory of Open Access Journals (Sweden)

    Deepak Bansal

    2016-01-01

    Full Text Available RF MEMS devices are known to be superior to their solid state counterparts in terms of power consumption and electromagnetic response. Major limitations of MEMS devices are their low switching speed, high actuation voltage, larger size, and reliability. In the present paper, a see-saw single pole double throw (SPDT RF MEMS switch based on anchor-free mechanism is proposed which eliminates the above-mentioned disadvantages. The proposed switch has a switching time of 394 nsec with actuation voltage of 5 V. Size of the SPDT switch is reduced by utilizing a single series capacitive switch compared to conventional switches with capacitive and series combinations. Reliability of the switch is improved by adding floating metal and reducing stiction between the actuating bridge and transmission line. Insertion loss and isolation are better than −0.6 dB and −20 dB, respectively, for 1 GHz to 20 GHz applications.

  8. Ultra-Low Voltage Class AB Switched Current Memory Cell

    DEFF Research Database (Denmark)

    Igor, Mucha

    1996-01-01

    This paper presents the theoretical basis for the design of class AB switched current memory cells employing floating-gate MOS transistors, suitable for ultra-low-voltage applications. To support the theoretical assumptions circuits based on these cells were designed using a CMOS process with thr......This paper presents the theoretical basis for the design of class AB switched current memory cells employing floating-gate MOS transistors, suitable for ultra-low-voltage applications. To support the theoretical assumptions circuits based on these cells were designed using a CMOS process...... with threshold voltages of 0.9V. Both hand calculations and PSPICE simulations showed that the cells designed allowed a maximum signal range better than +/-13 micoamp, with a supply voltage down to 1V and a quiescent bias current of 1 microamp, resulting in a very high current efficiency and effective power...

  9. Ultra-Low Voltage Class AB Switched Current Memory Cell

    DEFF Research Database (Denmark)

    Igor, Mucha

    1996-01-01

    This paper presents the theoretical basis for the design of class AB switched current memory cells employing floating-gate MOS transistors, suitable for ultra-low-voltage applications. To support the theoretical assumptions circuits based on these cells were designed using a CMOS process with thr......This paper presents the theoretical basis for the design of class AB switched current memory cells employing floating-gate MOS transistors, suitable for ultra-low-voltage applications. To support the theoretical assumptions circuits based on these cells were designed using a CMOS process...

  10. High voltage switch triggered by a laser-photocathode subsystem

    Science.gov (United States)

    Chen, Ping; Lundquist, Martin L.; Yu, David U. L.

    2013-01-08

    A spark gap switch for controlling the output of a high voltage pulse from a high voltage source, for example, a capacitor bank or a pulse forming network, to an external load such as a high gradient electron gun, laser, pulsed power accelerator or wide band radar. The combination of a UV laser and a high vacuum quartz cell, in which a photocathode and an anode are installed, is utilized as triggering devices to switch the spark gap from a non-conducting state to a conducting state with low delay and low jitter.

  11. Silicon-on-Insulator-Based Waveguide Switch with Fast Response

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuan-Yuan; LI Yun-Tao; XIA Jin-Song; LIU Jing-Wei; CHEN Shao-Wu; YU Jin-Zhong

    2005-01-01

    @@ Based on thermo-optical effect of silicon, a 2 × 2 switch is fabricated in silicon-on-insulator by chemical etching.The switch presents an extinction ratio of 26dB and a power consumption of 169mW. The response time is ~ 10.5μs.

  12. High-voltage picosecond photoconductor switch based on low-temperature-grown GaAs

    Science.gov (United States)

    Frankel, Michael Y.; Whitaker, John F.; Mourou, Gerard A.; Smith, Frank W.; Calawa, Arthur R.

    1990-01-01

    A GaAs material grown by molecular beam epitaxy at a low substrate temperature was used to fabricate a photoconductor switch that produces 6-V picosecond electrical pulses. The pulses were produced on a microwave coplanar-strip transmission line lithographically patterned on the low-temperature (LT) GaAs. A 150-fs laser pulse was used to generate carriers in the LT GaAs gap between the metal strips, partially shorting a high DC voltage placed across the lines. The 6-V magnitude of the electrical pulses obtained is believed to be limited by the laser pulse power and not by the properties of the LT GaAs. Experiments were also performed on a picosecond photoconductor switch fabricated on a conventional ion-damaged silicon-on-sapphire substrate. Although comparable pulse durations were obtained, the highest pulse voltage achieved with the latter device was 0.6 V.

  13. High-voltage, low-inductance gas switch

    Science.gov (United States)

    Gruner, Frederick R.; Stygar, William A.

    2016-03-22

    A low-inductance, air-insulated gas switch uses a de-enhanced annular trigger ring disposed between two opposing high voltage electrodes. The switch is DC chargeable to 200 kilovolts or more, triggerable, has low jitter (5 ns or less), has pre-fire and no-fire rates of no more than one in 10,000 shots, and has a lifetime of greater than 100,000 shots. Importantly, the switch also has a low inductance (less than 60 nH) and the ability to conduct currents with less than 100 ns rise times. The switch can be used with linear transformer drives or other pulsed-power systems.

  14. 160-Gb/s Silicon All-Optical Packet Switch for Buffer-less Optical Burst Switching

    DEFF Research Database (Denmark)

    Hu, Hao; Ji, Hua; Pu, Minhao;

    2015-01-01

    We experimentally demonstrate a 160-Gb/s Ethernet packet switch using an 8.6-mm-long silicon nanowire for optical burst switching, based on cross phase modulation in silicon. One of the four packets at the bit rate of 160 Gb/s is switched by an optical control signal using a silicon based 1 × 1 all......-optical packet switch. Error free performance (BER switched packet. The use of optical burst switching protocols could eliminate the need for optical buffering in silicon packet switch based optical burst switching, which might be desirable for high-speed interconnects within a short...

  15. Hybrid Voltage-Multipliers Based Switching Power Converters

    Science.gov (United States)

    Rosas-Caro, Julio C.; Mayo-Maldonado, Jonathan C.; Vazquez-Bautista, Rene Fabian; Valderrabano-Gonzalez, Antonio; Salas-Cabrera, Ruben; Valdez-Resendiz, Jesus Elias

    2011-08-01

    This work presents a derivation of PWM DC-DC hybrid converters by combining traditional converters with the Cockcroft-Walton voltage multiplier, the voltage multiplier of each converter is driven with the same transistor of the basic topology; this fact makes the structure of the new converters very simple and provides high-voltage gain. The traditional topologies discussed are the boost, buck-boost, Cuk and SEPIC. They main features of the discussed family are: (i) high-voltage gain without using extreme duty cycles or transformers, which allow high switching frequency and (ii) low voltage stress in switching devices, along with modular structures, and more output levels can be added without modifying the main circuit, which is highly desirable in some applications such as renewable energy generation systems. It is shown how a multiplier converter can become a generalized topology and how some of the traditional converters and several state-of-the-art converters can be derived from the generalized topologies and vice-versa. All the discussed converters were simulated, additionally experimental results are provided with an interleaved multiplier converter.

  16. Medium voltage switching techniques; Techniques de coupure en moyenne tension

    Energy Technology Data Exchange (ETDEWEB)

    Theoleyre, S. [Schneider Electric S.A., 92 - Boulogne-Billancourt (France)

    1999-08-01

    The link between power production plants and users is ensured by a grid or an arborescence of connections, lines and cables. For exploitation, maintenance or safety reasons it may be necessary to switch off and switch on the current at any point of the network. Switching devices are used for this purpose and the choice of a given device depends on the nature of the current (load, overload and fault currents) and of the domain of application. During switching and during continuous operation, these devices are submitted to dielectric, thermal, electrodynamical and mechanical stresses. The most important stresses are those linked with transient phenomena and involving an electric arc. This paper deals principally with the switching of medium voltage (1 to 52 kV) AC currents using circuit breakers. The first part analyzes the phenomena that occur during the operation of circuit breakers while the second part presents the four switching techniques currently used: in air, oil, vacuum and in sulfur hexafluoride (SF{sub 6}). (J.S.) 35 refs.

  17. Hybrid zero-voltage switching (ZVS) control for power inverters

    Science.gov (United States)

    Amirahmadi, Ahmadreza; Hu, Haibing; Batarseh, Issa

    2016-11-01

    A power inverter combination includes a half-bridge power inverter including first and second semiconductor power switches receiving input power having an intermediate node therebetween providing an inductor current through an inductor. A controller includes input comparison circuitry receiving the inductor current having outputs coupled to first inputs of pulse width modulation (PWM) generation circuitry, and a predictive control block having an output coupled to second inputs of the PWM generation circuitry. The predictive control block is coupled to receive a measure of Vin and an output voltage at a grid connection point. A memory stores a current control algorithm configured for resetting a PWM period for a switching signal applied to control nodes of the first and second power switch whenever the inductor current reaches a predetermined upper limit or a predetermined lower limit.

  18. 160-Gb/s Silicon All-Optical Packet Switch for Buffer-less Optical Burst Switching

    DEFF Research Database (Denmark)

    Hu, Hao; Ji, Hua; Pu, Minhao

    2015-01-01

    We experimentally demonstrate a 160-Gb/s Ethernet packet switch using an 8.6-mm-long silicon nanowire for optical burst switching, based on cross phase modulation in silicon. One of the four packets at the bit rate of 160 Gb/s is switched by an optical control signal using a silicon based 1 × 1 all-optical...... packet switch. Error free performance (BER optical burst switching protocols could eliminate the need for optical buffering in silicon packet switch based optical burst switching, which might be desirable for high-speed interconnects within a short...

  19. Silicone elastomers with aromatic voltage stabilizers

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Skov, Anne Ladegaard

    and benzene rings in PDMS-PPMS copolymer was measured by UV-vis spectroscopy. The developed elastomers were inherently soft with enhanced electrical breakdown strength due to delocalized pi-electrons of aromatic rings attached to the silicone backbone. The dielectric relative permittivity of PDMS...

  20. Low-profile high-voltage compact gas switch

    Energy Technology Data Exchange (ETDEWEB)

    Goerz, D.A.; Wilson, M.J.; Speer, R.D.

    1997-06-30

    This paper discusses the development and testing of a low-profile, high-voltage, spark-gap switch designed to be closely coupled with other components into an integrated high-energy pulsed-power source. The switch is designed to operate at 100 kV using SF6 gas pressurized to less than 0.7 MPa. The volume of the switch cavity region is less than 1.5 cm3, and the field stress along the gas-dielectric interface is as high as 130 kV/cm. The dielectric switch body has a low profile that is only I -cm tall at its greatest extent and nominally 2-mm thick over most of its area. This design achieves a very low inductance of less than 5 nH, but results in field stresses exceeding 500 kV/cm in the dielectric material. Field modeling was done to determine the appropriate shape for the highly stressed insulator and electrodes, and special manufacturing techniques were employed to mitigate the usual mechanisms that induce breakdown and failure in solid dielectrics. Static breakdown tests verified that the switch operates satisfactorily at 100 kV levels. The unit has been characterized with different shaped electrodes having nominal gap spacings of 2.0, 2.5, and 3.0 mm. The relationship between self-break voltage and operating pressure agrees well with published data on gas properties, accounting for the field enhancements of the electrode shapes being used. Capacitor discharge tests in a low inductance test fixture exhibited peak currents up to 25 kA with characteristic frequencies of the ringdown circuit ranging from 10 to 20 MHz. The ringdown waveforms and scaling of measured parameters agree well with circuit modeling of the switch and test fixture. Repetitive operation has been demonstrated at moderate rep-rates up to 15 Hz, limited by the power supply being used. Preliminary tests to evaluate lifetime of the compact switch assembly have been encouraging. In one case, after more than 7,000 high-current ringdown tests with approximately 30 C of total charge transferred, the

  1. Scaling silicon photonic switch fabrics for data center interconnection networks.

    Science.gov (United States)

    Nikolova, Dessislava; Rumley, Sébastien; Calhoun, David; Li, Qi; Hendry, Robert; Samadi, Payman; Bergman, Keren

    2015-01-26

    With the rapidly increasing aggregate bandwidth requirements of data centers there is a growing interest in the insertion of optically interconnected networks with high-radix transparent optical switch fabrics. Silicon photonics is a particularly promising and applicable technology due to its small footprint, CMOS compatibility, high bandwidth density, and the potential for nanosecond scale dynamic connectivity. In this paper we analyze the feasibility of building silicon photonic microring based switch fabrics for data center scale optical interconnection networks. We evaluate the scalability of a microring based switch fabric for WDM signals. Critical parameters including crosstalk, insertion loss and switching speed are analyzed, and their sensitivity with respect to device parameters is examined. We show that optimization of physical layer parameters can reduce crosstalk and increase switch fabric scalability. Our analysis indicates that with current state-of-the-art devices, a high radix 128 × 128 silicon photonic single chip switch fabric with tolerable power penalty is feasible. The applicability of silicon photonic microrings for data center switching is further supported via review of microring operations and control demonstrations. The challenges and opportunities for this technology platform are discussed.

  2. Temperature Induced Voltage Offset Drifts in Silicon Carbide Pressure Sensors

    Science.gov (United States)

    Okojie, Robert S.; Lukco, Dorothy; Nguyen, Vu; Savrun, Ender

    2012-01-01

    We report the reduction of transient drifts in the zero pressure offset voltage in silicon carbide (SiC) pressure sensors when operating at 600 C. The previously observed maximum drift of +/- 10 mV of the reference offset voltage at 600 C was reduced to within +/- 5 mV. The offset voltage drifts and bridge resistance changes over time at test temperature are explained in terms of the microstructure and phase changes occurring within the contact metallization, as analyzed by Auger electron spectroscopy and field emission scanning electron microscopy. The results have helped to identify the upper temperature reliable operational limit of this particular metallization scheme to be 605 C.

  3. A novel full soft-switching resonant power converter for mid-feeder voltage regulation of low voltage distribution network

    OpenAIRE

    Ji, Chao; Watson, Alan James; Clare, Jon C.; Johnson, Christopher Mark

    2016-01-01

    This paper presents a novel resonant based, high power density power electronics converter solution for mid-feeder voltage regulation of a low voltage (LV) distribution network. Owing to the use of high switching frequency operation and a full soft-switching control strategy, the proposed converter is capable of superimposing LV compensation into the feeder voltage, to achieve a significant system effect with a compact system volume and correspondingly smaller absolute power loss.

  4. High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

    Science.gov (United States)

    Bozak, Karin E.; Pinero, Luis R.; Scheidegger, Robert J.; Aulisio, Michael V.; Gonzalez, Marcelo C.; Birchenough, Arthur G.

    2015-01-01

    A silicon carbide brassboard power processing unit has been developed by the NASA Glenn Research Center in Cleveland, Ohio. The power processing unit operates from two sources: a nominal 300 Volt high voltage input bus and a nominal 28 Volt low voltage input bus. The design of the power processing unit includes four low voltage, low power auxiliary supplies, and two parallel 7.5 kilowatt (kW) discharge power supplies that are capable of providing up to 15 kilowatts of total power at 300 to 500 Volts (V) to the thruster. Additionally, the unit contains a housekeeping supply, high voltage input filter, low voltage input filter, and master control board, such that the complete brassboard unit is capable of operating a 12.5 kilowatt Hall effect thruster. The performance of the unit was characterized under both ambient and thermal vacuum test conditions, and the results demonstrate exceptional performance with full power efficiencies exceeding 97%. The unit was also tested with a 12.5kW Hall effect thruster to verify compatibility and output filter specifications. With space-qualified silicon carbide or similar high voltage, high efficiency power devices, this would provide a design solution to address the need for high power electric propulsion systems.

  5. Precise method for determining avalanche breakdown voltage of silicon photomultipliers

    Science.gov (United States)

    Chirikov-Zorin, I.

    2017-07-01

    A physically motivated method is proposed for determining the avalanche breakdown voltage of silicon photomultipliers (SiPM). The method is based on measuring the dependence of the relative photon detection efficiency (PDErel) on the bias voltage when one type of carriers (electron or hole) is injected into the avalanche multiplication zone of the p-n junction. The injection of electrons or holes from the base region of the SiPM semiconductor structure is performed using short-wave or long-wave light. At a low overvoltage (1-2 V) the detection efficiency is linearly dependent on the bias voltage; therefore, extrapolation to zero PDErel value determines the SiPM avalanche breakdown voltage with an accuracy within a few millivolts.

  6. Method and system for a gas tube switch-based voltage source high voltage direct current transmission system

    Energy Technology Data Exchange (ETDEWEB)

    She, Xu; Chokhawala, Rahul Shantilal; Zhou, Rui; Zhang, Di; Sommerer, Timothy John; Bray, James William

    2016-12-13

    A voltage source converter based high-voltage direct-current (HVDC) transmission system includes a voltage source converter (VSC)-based power converter channel. The VSC-based power converter channel includes an AC-DC converter and a DC-AC inverter electrically coupled to the AC-DC converter. The AC-DC converter and a DC-AC inverter include at least one gas tube switching device coupled in electrical anti-parallel with a respective gas tube diode. The VSC-based power converter channel includes a commutating circuit communicatively coupled to one or more of the at least one gas tube switching devices. The commutating circuit is configured to "switch on" a respective one of the one or more gas tube switching devices during a first portion of an operational cycle and "switch off" the respective one of the one or more gas tube switching devices during a second portion of the operational cycle.

  7. Silicon Modulators, Switches and Sub-systems for Optical Interconnect

    Science.gov (United States)

    Li, Qi

    Silicon photonics is emerging as a promising platform for manufacturing and integrating photonic devices for light generation, modulation, switching and detection. The compatibility with existing CMOS microelectronic foundries and high index contrast in silicon could enable low cost and high performance photonic systems, which find many applications in optical communication, data center networking and photonic network-on-chip. This thesis first develops and demonstrates several experimental work on high speed silicon modulators and switches with record performance and novel functionality. A 8x40 Gb/s transmitter based on silicon microrings is first presented. Then an end-to-end link using microrings for Binary Phase Shift Keying (BPSK) modulation and demodulation is shown, and its performance with conventional BPSK modulation/ demodulation techniques is compared. Next, a silicon traveling-wave Mach- Zehnder modulator is demonstrated at data rate up to 56 Gb/s for OOK modulation and 48 Gb/s for BPSK modulation, showing its capability at high speed communication systems. Then a single silicon microring is shown with 2x2 full crossbar switching functionality, enabling optical interconnects with ultra small footprint. Then several other experiments in the silicon platform are presented, including a fully integrated in-band Optical Signal to Noise Ratio (OSNR) monitor, characterization of optical power upper bound in a silicon microring modulator, and wavelength conversion in a dispersion-engineered waveguide. The last part of this thesis is on network-level application of photonics, specically a broadcast-and-select network based on star coupler is introduced, and its scalability performance is studied. Finally a novel switch architecture for data center networks is discussed, and its benefits as a disaggregated network are presented.

  8. Low voltage driven RF MEMS capacitive switch using reinforcement for reduced buckling

    Science.gov (United States)

    Bansal, Deepak; Bajpai, Anuroop; Kumar, Prem; Kaur, Maninder; Kumar, Amit; Chandran, Achu; Rangra, Kamaljit

    2017-02-01

    Variation in actuation voltage for RF MEMS switches is observed as a result of stress-generated buckling of MEMS structures. Large voltage driven RF-MEMS switches are a major concern in space bound communication applications. In this paper, we propose a low voltage driven RF MEMS capacitive switch with the introduction of perforations and reinforcement. The performance of the fabricated switch is compared with conventional capacitive RF MEMS switches. The pull-in voltage of the switch is reduced from 70 V to 16.2 V and the magnitude of deformation is reduced from 8 µm to 1 µm. The design of the reinforcement frame enhances the structural stiffness by 46 % without affecting the high frequency response of the switch. The measured isolation and insertion loss of the reinforced switch is more than 20 dB and 0.4 dB over the X band range.

  9. High-voltage, high-current, solid-state closing switch

    Energy Technology Data Exchange (ETDEWEB)

    Focia, Ronald Jeffrey

    2017-08-22

    A high-voltage, high-current, solid-state closing switch uses a field-effect transistor (e.g., a MOSFET) to trigger a high-voltage stack of thyristors. The switch can have a high hold-off voltage, high current carrying capacity, and high time-rate-of-change of current, di/dt. The fast closing switch can be used in pulsed power applications.

  10. Design and Simulation of a Low Actuation Voltage Capacitive Micro Electro Mechanical Systems’ (MEMS Switch

    Directory of Open Access Journals (Sweden)

    Ayub Soltani

    2014-09-01

    Full Text Available In this paper we have proposed a new switch or structure for reducing actuation voltage. This switch is compared with four conventional structures considering the force range of 1uN to 3uN. We have used the ANSYS software for design and simulation for the switch parameters such as actuation voltage, collapse voltage, spring constant and resonant frequency. Small size (half of the size of other proposed materials, which can reduce the manufacturing cost, and also low-valued spring constant, which results in actuation voltage reduction, are among more noticeable features of the proposed switch.

  11. Silicon solar cells with high open-circuit voltage

    Science.gov (United States)

    Minnucci, J. A.; Matthei, K. W.; Kirkpatrick, A. R.; Mccrosky, A.

    1980-01-01

    Open-circuit voltages as high as 0.645 V (AM0-25 C) have been obtained by a new process developed for low-resistivity silicon. The method utilizes high-dose phosphorus implantation, followed by furnace annealing and simultaneous oxide growth to form high-efficiency, shallow junctions. The effect of the thermally grown oxide is a reduction of surface recombination velocity; the oxide also acts as a moderately efficient AR coating. Boron doped silicon with resistivities from 0.1 to 0.3 ohm-cm has been processed according to this sequence; results show highest open-circuit voltage is attained with 0.1-ohm-cm starting material. The effects of bandgap narrowing, caused by high doping concentrations in the junction, were also investigated by implanting phosphorus over a wide range of dose levels.

  12. Low pull-in voltage electrostatic MEMS switch using liquid dielectric

    KAUST Repository

    Zidan, Mohammed A.

    2014-08-01

    In this paper, we present an electrostatic MEMS switch with liquids as dielectric to reduce the actuation voltage. The concept is verified by simulating a lateral dual gate switch, where the required pull-in voltage is reduced by more than 8 times after using water as a dielectric, to become as low as 5.36V. The proposed switch is simulated using COMSOL multiphysics using various liquid volumes to study their effect on the switching performance. Finally, we propose the usage of the lateral switch as a single switch XOR logic gate.

  13. Silicon ohmic lateral-contact MEMS switch for RF applications

    Science.gov (United States)

    Rogozhin, A.; Miakonkikh, A.; Tatarintsev, A.; Lebedev, K.; Kalnov, V.; Rudenko, K.; Lukichev, V.

    2016-12-01

    Application variety and huge potential market of RF MEMS switches guarantee relentless research interest to the field. There are lots of different types of MEMS switches. Direct contact MEMS switches are simplifier for integration than capacitive MEMS switches. Lateral technology considerably simplifies the formation process. The objective of this research is to estimate characteristics of the simple direct-contact lateral MEMS switch and to understand the improvement directions. The MEMS switches were fabricated on the SOI wafers by e-beam lithography, dry etching and wet HF-etching. E-beam lithography and dry etching were used to form the cantilever and electrodes on the buried oxide layer. The structure with two control electrodes was used. IV characteristics were measured by Keithley 4200-SCS. The distance between cantilever and control electrodes was 100 nm. From the obtained IV characteristics it is clear that the devices switches at about 60 V. High control voltage could be explained by the large distance between cantilever and control electrode, and high rigidity of the cantilever. Following simulation in COMSOL Multiphysics showed that the control voltage could be decreased to 20-30 V by adding of spring element to the cantilever and device geometry modification.

  14. Effect of Solar Array Capacitance on the Performance of Switching Shunt Voltage Regulator

    OpenAIRE

    Kumar, Anil R; Suresh, MS; Nagaraju, J

    2006-01-01

    Due to high power demand photovoltaic regulators are being switched at high frequency. The solar cell capacitance increases the ripple voltage of the switching regulators at higher switching frequencies. Increased ripple due to array capacitance is calculated and its effect in limiting the maximum design switching frequency is studied. An experimental switching regulator is designed and used to confirm the theoretical considerations. This study has identified a method of solar cell capacitanc...

  15. Air Breakdown Behavior of Two Series Gaps for Composite Switching Impulse/Alternating Voltage

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    More and more high voltage transmission lines make use of rubber housed ZnO arresters in series with another air gap (for example, the insulator gap) as lighting protection elements. Many test results of ZnO arresters protection performance show that this insulation arrangement is suitable for practical lines according to results based on only simple impulse voltage. This paper uses a composite voltage (switching impulse voltage/alternating voltage) to determine the air breakdown behavior of the conductor-rod gap in series with the sphere gap. In the test, the switching impulse voltage is applied to the conductor while the alternating voltage is applied to the rod and one sphere and the other sphere is grounded. The results show that in some cases, the value of the U50% sparkover voltage for the conductor-rod gap with the composite voltage is nearly only half of that for just the simple impulse voltage.

  16. Cascaded transformerless DC-DC voltage amplifier with optically isolated switching devices

    Science.gov (United States)

    Sridharan, Govind (Inventor)

    1993-01-01

    A very high voltage amplifier is provided in which plural cascaded banks of capacitors are switched by optically isolated control switches so as to be charged in parallel from the preceding stage or capacitor bank and to discharge in series to the succeeding stage or capacitor bank in alternating control cycles. The optically isolated control switches are controlled by a logic controller whose power supply is virtually immune to interference from the very high voltage output of the amplifier by the optical isolation provided by the switches, so that a very high voltage amplification ratio may be attained using many capacitor banks in cascade.

  17. Reconfigurable SDM Switching Using Novel Silicon Photonic Integrated Circuit

    CERN Document Server

    Ding, Yunhong; Dalgaard, Kjeld; Ye, Feihong; Asif, Rameez; Gross, Simon; Withford, Michael J; Galili, Michael; Morioka, Toshio; Oxenlowe, Leif Katsuo

    2016-01-01

    Space division multiplexing using multicore fibers is becoming a more and more promising technology. In space-division multiplexing fiber network, the reconfigurable switch is one of the most critical components in network nodes. In this paper we for the first time demonstrate reconfigurable space-division multiplexing switching using silicon photonic integrated circuit, which is fabricated on a novel silicon-on-insulator platform with buried Al mirror. The silicon photonic integrated circuit is composed of a 7x7 switch and low loss grating coupler array based multicore fiber couplers. Thanks to the Al mirror, grating couplers with ultra-low coupling loss with optical multicore fibers is achieved. The lowest total insertion loss of the silicon integrated circuit is as low as 4.5 dB, with low crosstalk lower than -30 dB. Excellent performances in terms of low insertion loss and low crosstalk are obtained for the whole C-band. 1 Tb/s/core transmission over a 2-km 7-core fiber and space-division multiplexing swi...

  18. Analysis of bi-directional piezoelectric-based converters for zero-voltage switching operation

    DEFF Research Database (Denmark)

    Ekhtiari, Marzieh; Zhang, Zhe; Andersen, Michael A. E.

    2016-01-01

    This paper deals with a thorough analysis of zerovoltage switching especially for bi-directional, inductorless, piezoelectric transformer-based switch-mode power supplies with a half-bridge topology. Practically, obtaining zero-voltage switching for all of the switches in a bi......-directional piezoelectric power converter is a difficult task. However, the analysis in this work will be convenient for overcoming this challenge. The analysis defines the zero-voltage region indicating the operating points whether or not soft switching can be met over the switching frequency and load range. For the first...... time, a comprehensive analysis is provided, which can be used as a design guideline for applying control techniques in order to drive switches in piezoelectric transformer-based converters. This study further conveys the proposed method to the region where all the switches can obtain soft switching...

  19. Medium voltage SF6 switch rooms with switch breakers; Cubiculos de media tensao em SF6 com disjuntores

    Energy Technology Data Exchange (ETDEWEB)

    Matias, Marcos [Schneider Electric Brasil, Sao Paulo, SP (Brazil)

    1999-07-01

    This paper describes the technology using SF6 as breaking gas and the application in medium and high voltage switch rooms. The paper also describes the metal clad panel, the ring main unit, the medium voltage, and the panel saw and circuit breakers with SF6.

  20. High Voltage Operation of heavily irradiated silicon microstrip detectors

    CERN Document Server

    Gu, W H; Angarano, M M; Bader, A; Biggeri, U; Boemi, D; Braibant, S; Breuker, H; Bruzzi, Mara; Caner, A; Catacchini, E; Civinini, C; Creanza, D; D'Alessandro, R; Demaria, N; Eklund, C; Peisert, Anna; Feld, L; Fiore, L; Focardi, E; Fürtjes, A; Glessing, B; Hall, G; Hammerstrom, R; Dollan, Ralph; Huhtinen, M; Karimäki, V; König, S; Lenzi, M; Lübelsmeyer, K; Maggi, G; Mannelli, M; Marchioro, A; Mariotti, C; Mättig, P; McEvoy, B; Meschini, M; My, S; Pandoulas, D; Parrini, G; Pieri, M; Dollan, Ralph; Potenza, R; Raso, G; Raymond, M; Schmitt, B; Selvaggi, G; Siedling, R; Silvestris, L; Skog, K; Stefanini, G; Tempesta, P; Tricomi, A; Watts, S; Wittmer, B; De Palma, M

    1999-01-01

    We discuss the results obtained from the R&D studies, done within the CMS experiment at LHC related to the behaviour of silicon microstrip prototype detectors when they are operated at high bias voltages before and after heavy irradiation, simulating up to 10 years of LHC running conditions. We have found detectors from several manufacturesrs that are able to work at V_bias > 500 Volts before and after the irradiation procedure, maintaining an acceptable performance with S/N > 14, efficiency close to 100% and few ghost hits.

  1. Efficient Hardware Trojan Detection with Differential Cascade Voltage Switch Logic

    Directory of Open Access Journals (Sweden)

    Wafi Danesh

    2014-01-01

    Full Text Available Offshore fabrication, assembling and packaging challenge chip security, as original chip designs may be tampered by malicious insertions, known as hardware Trojans (HTs. HT detection is imperative to guarantee the chip performance and safety. Existing HT detection methods have limited capability to detect small-scale HTs and are further challenged by the increased process variation. To increase HT detection sensitivity and reduce chip authorization time, we propose to exploit the inherent feature of differential cascade voltage switch logic (DCVSL to detect HTs at runtime. In normal operation, a system implemented with DCVSL always produces complementary logic values in internal nets and final outputs. Noncomplementary values on inputs and internal nets in DCVSL systems potentially result in abnormal power behavior and even system failures. By examining special power characteristics of DCVSL systems upon HT insertion, we can detect HTs, even if the HT size is small. Simulation results show that the proposed method achieves up to 100% HT detection rate. The evaluation on ISCAS benchmark circuits shows that the proposed method obtains a HT detection rate in the range of 66% to 98%.

  2. Optical Switching in Silicon Nanowaveguide Ring Resonators Based on Kerr Effect and TPA Effect

    Institute of Scientific and Technical Information of China (English)

    LI Chun-Fei; DOU Na

    2009-01-01

    We analyze theoretically the 1 × 2 low-power all-optical switching in silicon nanowaveguide ring resonators (RR) based on the Kerr effect and two-photon absorption (TPA), and give a comparison between both the all-optical switches. The calculation shows that the switching power of the TPA-RR switch is 3 orders smaller than that of the Kerr-RR switch. The switching time for both the switches is about 100ps.

  3. A New Zero Voltage Switching Buck-Boost Type DC-DC Converter

    Directory of Open Access Journals (Sweden)

    Majid Delshad

    2010-03-01

    Full Text Available In this paper, a new zero voltage switching isolated buck-boost DC-DC converter with active clamp circuit is proposed. The active clamp circuit in this converter not only absorbs voltage spikes across the main switch but also provides soft switching conditions for all switches. All switches are PWM controlled which simplifies the control implementation. One of the main advantages of this converter is the that it operating can operate at high power levels while soft switching conditions exist in both buck and boost modes of converter operation. Since this converter can operate over a wide input voltage range, it can be employed in power factor correction. The experimental results obtained from a 150W prototype circuit operating at 100KHz are presented to confirm the integrity of the proposed circuit.

  4. Four-Switch Three-Phase PMSM Converter with Output Voltage Balance and DC-Link Voltage Offset Suppression

    Directory of Open Access Journals (Sweden)

    Fadil Hicham

    2017-01-01

    Full Text Available High power quality, efficiency, complexity, size, cost effectiveness and switching losses of the direct current to alternating current (DC–AC conversion system are crucial aspects in industrial applications. Therefore, the four-switch three-phase inverter (4S3P has been proposed as an innovative inverter design. However, this topology has been known to have many performance limitations in the low-frequency region, because of the generation of an unbalanced voltage leading to an unbalanced current due to the fluctuation and offset of the centre tap voltage of the DC-link capacitors. Those drawbacks are investigated and solved in this paper in order to provide pure sinusoidal output voltages. The generated output voltages are controlled using proportional-integral (PI controllers to follow the desired voltages. Furthermore, the DC-link capacitor voltage offset is mitigated by subtracting the direct component from the control reference voltage using low pass filters, where this direct voltage component provides the direct current component which leads to DC-link capacitor voltage divergence. A simulation model and experimental setup are used to validate the proposed concept. Many simulation and experimental results are carried out to show the effectiveness of the proposed control scheme.

  5. A novel high voltage start up circuit for an integrated switched mode power supply

    Energy Technology Data Exchange (ETDEWEB)

    Hu Hao; Chen Xingbi, E-mail: huhao21@uestc.edu.c [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2010-09-15

    A novel high voltage start up circuit for providing an initial bias voltage to an integrated switched mode power supply (SMPS) is presented. An enhanced mode VDMOS transistor, the gate of which is biased by a floating p-island, is used to provide start up current and sustain high voltage. An NMOS transistor having a high source to ground breakdown voltage is included to extend the bias voltage range to the SMPS. Simulation results indicate that the high voltage start up circuit can start and restart as designed. The proposed structure is believed to be more energy saving and cost-effective compared with other solutions. (semiconductor devices)

  6. SEMICONDUCTOR DEVICES: A novel high voltage start up circuit for an integrated switched mode power supply

    Science.gov (United States)

    Hao, Hu; Xingbi, Chen

    2010-09-01

    A novel high voltage start up circuit for providing an initial bias voltage to an integrated switched mode power supply (SMPS) is presented. An enhanced mode VDMOS transistor, the gate of which is biased by a floating p-island, is used to provide start up current and sustain high voltage. An NMOS transistor having a high source to ground breakdown voltage is included to extend the bias voltage range to the SMPS. Simulation results indicate that the high voltage start up circuit can start and restart as designed. The proposed structure is believed to be more energy saving and cost-effective compared with other solutions.

  7. Electronic devices containing switchably conductive silicon oxides as a switching element and methods for production and use thereof

    Science.gov (United States)

    Tour, James M; Yao, Jun; Natelson, Douglas; Zhong, Lin; He, Tao

    2013-11-26

    In various embodiments, electronic devices containing switchably conductive silicon oxide as a switching element are described herein. The electronic devices are two-terminal devices containing a first electrical contact and a second electrical contact in which at least one of the first electrical contact or the second electrical contact is deposed on a substrate to define a gap region therebetween. A switching layer containing a switchably conductive silicon oxide resides in the the gap region between the first electical contact and the second electrical contact. The electronic devices exhibit hysteretic current versus voltage properties, enabling their use in switching and memory applications. Methods for configuring, operating and constructing the electronic devices are also presented herein.

  8. A Component-Reduced Zero-Voltage Switching Three-Level DC-DC Converter

    DEFF Research Database (Denmark)

    Qin, Zian; Pang, Ying; Wang, Huai;

    2016-01-01

    The basic Zero-Voltage Switching (ZVS) three-level DC-DC converter has one clamping capacitor to realize the ZVS of the switches, and two clamping diodes to clamp the voltage of the clamping capacitor. In order to reduce the reverse recovery loss of the diode as well as its cost, this paper...... proposes to remove one of the clamping diodes in basic ZVS three-level DC-DC converter. With less components, the proposed converter can still have a stable clamping capacitor voltage, which is clamped at half of the dc link voltage. Moreover, the ZVS performance will be influenced by removing the clamping...

  9. An X band RF MEMS switch based on silicon-on-glass architecture

    Indian Academy of Sciences (India)

    M S Giridhar; Ashwini Jambhalikar; J John; R Islam; C L Nagendra; T K Alex

    2009-08-01

    Communication systems such as those used on satellite platforms demand high performance from individual components that make up the varoius systems and sub-systems. Switching and routing of RF signals between various modules is a routine and critical operation that determines the overall efficiency of the entire system. In this paper, we present the design and fabrication aspects of a direct contact RF MEMS switch designed to operate in the X band (8–12 GHz) with a target insertion of about 0·5 dB and isolation better than 30 dB. The actuation voltage is expected to be around 50 V. The die size is designed to be 3 mm (H) × 3 mm(W) × 2 mm(H). The switch is built from a low residual stress device layer of a highly conducting (0·005 Ohms-cm) silicon on insulator (SOI) wafer. After subsequent lithographic steps, the wafer is bonded to a Pyrex glass wafer which has been previously patterned with gold transmission lines and pull in electrodes. Being built from a single crystal silicon structure, the mechanical robustness of the actuator is much greater than the those in similar membrane-based devices. A 6 mask fabrication process utilizing Deep Reactive Ion Etching to achieve high aspect ratio stiction free structures was developed and implemented. Devices from the first fabrication run are being analysed in our laboratory.

  10. Ultra Low Voltage Class AB Switched Current Memory Cells Based on Floating Gate Transistors

    DEFF Research Database (Denmark)

    Mucha, Igor

    1999-01-01

    A proposal for a class AB switched current memory cell, suitable for ultra-low-voltage applications is presented. The proposal employs transistors with floating gates, allowing to build analog building blocks for ultralow supply voltage operation also in CMOS processes with high threshold voltages....... This paper presents the theoretical basis for the design of "floating-gate'' switched current memory cells by giving a detailed description and analysis of the most important impacts degrading the performance of the cells. To support the theoretical assumptions circuits based on "floating-gate'' switched...... current memory cells were designed using a CMOS process with threshold voltages V-T0n = \\V-T0p\\ = 0.9 V for the n- and p-channel devices. Both hand calculations and PSPICE simulations showed that the designed example switched current memory cell allowed a maximum signal range better than +/-18 mu...

  11. SOFT-SWITCHED HIGH STEP-UP DC-DC CONVERTER WITH HIGH VOLTAGE GAIN

    Directory of Open Access Journals (Sweden)

    J.C. PAUL IMMANUEL

    2013-04-01

    Full Text Available This paper presents a new design of soft switched high step-up dc-dc converter with high voltage gain which is suitable for high power applications such as Uninterruptible Power System (UPS, Photo Voltaic system and hybrid electric vehicles. The emergence of this front-end converter is to improve the shape of active input current given to the system. This converter proposes Soft-Switching technique to achieve ZVS turn on of active switches and ZCS turn off of diodes using Lr - Cr resonance in the auxiliary circuit. Therefore reduces the switching losses. Comparatively the voltage conversion ratio of this converter is higher when compared with the ordinary boost converter. Hence the voltage gain of this converter is also higher. A simulation platform is created using MATLAB which illustrates the ZVS and ZCS operation of the switches and diodes. Open loop and closed loop controlled converter systems are modelled and simulated.

  12. Effects of Direct Torque Control Switching Strategies on Common Voltage and Bearing Current

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Sadeghzadeh

    2012-04-01

    Full Text Available Bearing current sininduction motorsare considered a sone of the most damaging factors. Induced shaft voltage through the parasitic capacitors cause this type of current. Inthispaper,given the increasing importance of direct torque control of induction motorin industry, various switching tables are assessed in order to ensure the lowest common voltage while maintaining the performance characteristics of the drive. Finally best switching table based on the minimum CMV, less torque rippleand better quality out put reference tracking is proposed.

  13. Current measurement method for characterization of fast switching power semiconductors with Silicon Steel Current Transformer

    DEFF Research Database (Denmark)

    Li, Helong; Beczkowski, Szymon; Munk-Nielsen, Stig

    2015-01-01

    This paper proposes a novel current measurement method with Silicon Steel Current Transformer (SSCT) for the characterization of fast switching power semiconductors. First, the existing current sensors for characterization of fast switching power semiconductors are experimentally evaluated...

  14. 160 Gbit/s optical packet switching using a silicon chip

    DEFF Research Database (Denmark)

    Hu, Hao; Ji, Hua; Galili, Michael;

    2012-01-01

    We have successfully demonstrated 160 Gbit/s all-optical packet switching based on cross-phase modulation using a silicon chip. Error free performance is achieved for the 4-to-1 switched 160 Gbit/s packet....

  15. Development of A Maintenance Device for Bus-bar PT Voltage Air Switch

    Directory of Open Access Journals (Sweden)

    Zhang Xiang

    2017-01-01

    Full Text Available When PT breaks down, it takes long time of switching operation before maintenance, which seriously delays the restoration time. Based on the principle of multiple circuit, a live replacement maintenance device for PT voltage air switch is proposed. The following aspects are involved in the design of the device: the principle of device, component selection, device’s assembly and operation process. Through functional test in simulation substation and on-site installation, it is proved that the failed air switch can be lively replaced by the device without switching operation, which greatly reduces the risk on power grid caused by such faulted air switch.

  16. Low Actuation Voltage RF MEMS Switch Using Varying Section Composite Fixed-Fixed Beam

    Directory of Open Access Journals (Sweden)

    M. Manivannan

    2014-01-01

    Full Text Available The present authors have earlier reported the employment of varying section fixed-fixed beam for achieving lower pull-in voltage with marginal fall in restoring force. Reducing Young’s modulus also reduces the pull-in voltage but with lesser degree of reduction in restoring force. Composite beams are ideal alternatives to achieve decreased Young’s modulus. Hence new varying section composite fixed-fixed beam type RF MEMS switch has been proposed. The main advantage of this RF MEMS switch is that lower pull-in voltages can be achieved with marginal fall in stiction immunity. Spring constant of the proposed switch has been obtained using simulation studies and it has been shown that the spring constant and therefore the pull-in voltage (Vpi can be considerably reduced with the proposed switch. Simulation studies conducted on the proposed switch clearly demonstrate that the pull-in voltage can be reduced by 31.17% when compared to the varying section monolayer polysilicon fixed-fixed beam. Further this approach enables the designer to have more freedom to design lower pull-in voltage switches with improved stiction immunity.

  17. Experimental Demonstration of 7 Tb/s Switching Using Novel Silicon Photonic Integrated Circuit

    DEFF Research Database (Denmark)

    Ding, Yunhong; Kamchevska, Valerija; Dalgaard, Kjeld

    2016-01-01

    We demonstrate BER performance <10^-9 for a 1 Tb/s/core transmission over 7-core fiber and SDM switching using a novel silicon photonic integrated circuit composed of a 7x7 fiber switch and low loss SDM couplers.......We demonstrate BER performance Tb/s/core transmission over 7-core fiber and SDM switching using a novel silicon photonic integrated circuit composed of a 7x7 fiber switch and low loss SDM couplers....

  18. Simultaneous On-State Voltage and Bond-Wire Resistance Monitoring of Silicon Carbide MOSFETs

    Directory of Open Access Journals (Sweden)

    Nick Baker

    2017-03-01

    Full Text Available In fast switching power semiconductors, the use of a fourth terminal to provide the reference potential for the gate signal—known as a kelvin-source terminal—is becoming common. The introduction of this terminal presents opportunities for condition monitoring systems. This article demonstrates how the voltage between the kelvin-source and power-source can be used to specifically monitor bond-wire degradation. Meanwhile, the drain to kelvin-source voltage can be monitored to track defects in the semiconductor die or gate driver. Through an accelerated aging test on 20 A Silicon Carbide Metal-Oxide-Semiconductor-Field-Effect Transistors (MOSFETs, it is shown that there are opposing trends in the evolution of the on-state resistances of both the bond-wires and the MOSFET die. In summary, after 50,000 temperature cycles, the resistance of the bond-wires increased by up to 2 mΩ, while the on-state resistance of the MOSFET dies decreased by approximately 1 mΩ. The conventional failure precursor (monitoring a single forward voltage cannot distinguish between semiconductor die or bond-wire degradation. Therefore, the ability to monitor both these parameters due to the presence of an auxiliary-source terminal can provide more detailed information regarding the aging process of a device.

  19. Voltage-Balancing Method for Modular Multilevel Converters Switched at Grid Frequency

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2015-01-01

    The modular multilevel converter (MMC) becomes attractive for high-voltage and high-power applications due to its high modularity, availability, and power quality. The voltage balance issue of capacitors is very important in the MMC, and the balancing of the capacitor voltage is increasingly...... difficult as the switching frequency is reduced. In this paper, a voltage-balancing method is proposed for the MMC switched at grid frequency with reduced losses and does not rely on the arm current. By assigning the low-frequency pulses with different pulse widths, the capacitor charge transfer in the MMC...... can be controlled for keeping the capacitor voltage balancing in the MMC. Simulations and experimental studies of the MMC are conducted, and the results confirm the effectiveness of the proposed capacitor voltage-balancing method....

  20. Dynamical model of series-resonant converter with peak capacitor voltage predictor and switching frequency control

    Science.gov (United States)

    Pietkiewicz, A.; Tollik, D.; Klaassens, J. B.

    1989-08-01

    A simple small-signal low-frequency model of an idealized series resonant converter employing peak capacitor voltage prediction and switching frequency control is proposed. Two different versions of the model describe all possible conversion modes. It is found that step down modes offer better dynamic characteristics over most important network functions than do the step-up modes. The dynamical model of the series resonant converter with peak capacitor voltage prediction and switching frequency programming is much simpler than such popular control stategies as frequency VCO (voltage controlled oscillators) based control, or diode conduction angle control.

  1. A consistent approach to estimate the breakdown voltage of high voltage electrodes under positive switching impulses

    Science.gov (United States)

    Arevalo, L.; Wu, D.; Jacobson, B.

    2013-08-01

    The main propose of this paper is to present a physical model of long air gap electrical discharges under positive switching impulses. The development and progression of discharges in long air gaps are attributable to two intertwined physical phenomena, namely, the leader channel and the streamer zone. Experimental studies have been used to develop empirical and physical models capable to represent the streamer zone and the leader channel. The empirical ones have led to improvements in the electrical design of high voltage apparatus and insulation distances, but they cannot take into account factors associated with fundamental physics and/or the behavior of materials. The physical models have been used to describe and understand the discharge phenomena of laboratory and lightning discharges. However, because of the complex simulations necessary to reproduce real cases, they are not in widespread use in the engineering of practical applications. Hence, the aim of the work presented here is to develop a model based on physics of the discharge capable to validate and complement the existing engineering models. The model presented here proposes a new geometrical approximation for the representation of the streamer and the calculation of the accumulated electrical charge. The model considers a variable streamer region that changes with the temporal and spatial variations of the electric field. The leader channel is modeled using the non local thermo-equilibrium equations. Furthermore, statistical delays before the inception of the first corona, and random distributions to represent the tortuous nature of the path taken by the leader channel were included based on the behavior observed in experimental tests, with the intention of ensuring the discharge behaved in a realistic manner. For comparison purposes, two different gap configurations were simulated. A reasonable agreement was found between the physical model and the experimental test results.

  2. Voltage-Driven Magnetization Switching and Spin Pumping in Weyl Semimetals

    Science.gov (United States)

    Kurebayashi, Daichi; Nomura, Kentaro

    2016-10-01

    We demonstrate electrical magnetization switching and spin pumping in magnetically doped Weyl semimetals. The Weyl semimetal is a three-dimensional gapless topological material, known to have nontrivial coupling between the charge and the magnetization due to the chiral anomaly. By solving the Landau-Lifshitz-Gilbert equation for a multilayer structure of a Weyl semimetal, an insulator and a metal while taking the charge-magnetization coupling into account, magnetization dynamics is analyzed. It is shown that the magnetization dynamics can be driven by the electric voltage. Consequently, switching of the magnetization with a pulsed electric voltage can be achieved, as well as precession motion with an applied oscillating electric voltage. The effect requires only a short voltage pulse and may therefore be energetically favorable for us in spintronics devices compared to conventional spin-transfer torque switching.

  3. A low-power circuit for piezoelectric vibration control by synchronized switching on voltage sources

    CERN Document Server

    Shen, Hui; Ji, Hongli; Zhu, Kongjun; Balsi, Marco; Giorgio, Ivan; dell'Isola, Francesco

    2010-01-01

    In the paper, a vibration damping system powered by harvested energy with implementation of the so-called SSDV (synchronized switch damping on voltage source) technique is designed and investigated. In the semi-passive approach, the piezoelectric element is intermittently switched from open-circuit to specific impedance synchronously with the structural vibration. Due to this switching procedure, a phase difference appears between the strain induced by vibration and the resulting voltage, thus creating energy dissipation. By supplying the energy collected from the piezoelectric materials to the switching circuit, a new low-power device using the SSDV technique is proposed. Compared with the original self-powered SSDI (synchronized switch damping on inductor), such a device can significantly improve its performance of vibration control. Its effectiveness in the single-mode resonant damping of a composite beam is validated by the experimental results.

  4. Voltage switching of a VO{sub 2} memory metasurface using ionic gel

    Energy Technology Data Exchange (ETDEWEB)

    Goldflam, M. D.; Liu, M. K.; Chapler, B. C.; Stinson, H. T.; Sternbach, A. J.; McLeod, A. S.; Basov, D. N., E-mail: dbasov@physics.ucsd.edu [Department of Physics, The University of California at San Diego, La Jolla, California 92093 (United States); Zhang, J. D.; Geng, K. [Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Royal, M.; Jokerst, N. M.; Smith, D. R. [Center for Metamaterials and Integrated Plasmonics, Pratt School of Engineering, Duke University, Durham, North Carolina 27708 (United States); Kim, Bong-Jun [Metal-Insulator Transition Creative Research Center, ETRI, Daejeon 305-350 (Korea, Republic of); Averitt, R. D. [Department of Physics, The University of California at San Diego, La Jolla, California 92093 (United States); Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Kim, H-T. [Metal-Insulator Transition Creative Research Center, ETRI, Daejeon 305-350 (Korea, Republic of); School of Advanced Device Technology, University of Science and Technology, Daejeon 305-333 (Korea, Republic of)

    2014-07-28

    We demonstrate an electrolyte-based voltage tunable vanadium dioxide (VO{sub 2}) memory metasurface. Large spatial scale, low voltage, non-volatile switching of terahertz (THz) metasurface resonances is achieved through voltage application using an ionic gel to drive the insulator-to-metal transition in an underlying VO{sub 2} layer. Positive and negative voltage application can selectively tune the metasurface resonance into the “off” or “on” state by pushing the VO{sub 2} into a more conductive or insulating regime respectively. Compared to graphene based control devices, the relatively long saturation time of resonance modification in VO{sub 2} based devices suggests that this voltage-induced switching originates primarily from electrochemical effects related to oxygen migration across the electrolyte–VO{sub 2} interface.

  5. Determination of appropriate DC voltage for switched mode power supply (SMPS) loads

    Science.gov (United States)

    Setiawan, Eko Adhi; Setiawan, Aiman; Purnomo, Andri; Djamal, Muchlishah Hadi

    2017-03-01

    Nowadays, most of modern and efficient household electronic devices operated based on Switched Mode Power Supply (SMPS) technology which convert AC voltage from the grid to DC voltage. Based on theory and experiment, SMPS loads could be supplied by DC voltage. However, the DC voltage rating to energize electronic home appliances is not standardized yet. This paper proposed certain method to determine appropriate DC voltage, and investigated comparison of SMPS power consumption which is supplied from AC and DC voltage. To determine the appropriate DC voltage, lux value of several lamps which have same specification energized by using AC voltage and the results is using as reference. Then, the lamps were supplied by various DC voltage to obtain the trends of the lux value to the applied DC voltage. After that, by using the trends and the reference lux value, the appropriate DC voltage can be determined. Furthermore, the power consumption on home appliances such as mobile phone, laptop and personal computer by using AC voltage and the appropriate DC voltage were conducted. The results show that the total power consumption of AC system is higher than DC system. The total power (apparent power) consumed by the lamp, mobile phone and personal computer which operated in 220 VAC were 6.93 VA, 34.31 VA and 105.85 VA respectively. On the other hand, under 277 VDC the load consumption were 5.83 W, 19.11 W and 74.46 W respectively.

  6. Switching performance and efficiency investigation of GaN based DC-DC Buck converter for low voltage and high current applications

    Science.gov (United States)

    Alatawi, Khaled; Almasoudi, Fahad; Matin, Mohammad

    2016-09-01

    The Wide band-gap (WBG) materials "such as Silicon Carbide (SiC) and Gallium nitride (GaN)" based power switching devices provide higher performance capabilities compared to Si-based power switching devices. The wide band-gap materials based power switching devices outperform Si-based devices in many performance characteristics such as: low witching loss, low conduction loss, high switching frequencies, and high operation temperature. GaN based switching devices benefit a lot of applications such as: future electric vehicles and solar power inverters. In this paper, a DC-DC Buck converter based on GaN FET for low voltage and high current applications is designed and investigated. The converter is designed for stepping down a voltage of 48V to 12V with high switching frequency. The capability of the GaN FET based buck converter is studied and compared to equivalent SiC MOSFET and Si-based MOSFET buck converters. The analysis of switching losses and efficiency was performed to compare the performance capabilities of GaN FET, SiC MOSFET and Si-based MOSFET. The results showed that the overall switching losses of GaN FET are lower than that of SiC and Si-based power switching devices. Also, the performance capability of GaN devices with higher frequencies is studied. GaN devices with high frequencies will reduce the total size and the cost of the power converter. In Addition, the overall efficiency of the DC-DC Buck converter is higher with the GaN FET switching devices, which make it more suitable for low voltage and high current applications.

  7. Zero-voltage switching converter absorbing parasitic parameters for super high frequency induction heating

    Institute of Scientific and Technical Information of China (English)

    Zheng-shi WANG; Hui-ming CHEN

    2008-01-01

    This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive and capacitive parasitic components in the converter. The switch devices operate in a zero-voltage soft-switching mode. Consequently, the high voltage and high current spikes caused by parasitic inductors or capacitors oscillation do not occur in this circuit, and the high power loss caused by high frequency switching can be greatly reduced. A large value inductor is adopted between the input capacitor and the switches, thus, this novel converter shares the benefits of both voltage-type and current-type circuits simultaneously, and there are no needs of dead time between two switches. The working principles in different modes are introduced, Results of simulation and experiments operated at around 1 MHz frequency verify the validity of parasitic components absorption and show that this converter is competent for super high frequency applications.

  8. Low-frequency switching voltage regulators for terrestrial photovoltaic systems

    Science.gov (United States)

    Delombard, R.

    1984-01-01

    The photovoltaic technology project and the stand alone applications project are discussed. Two types of low frequency switching type regulators were investigated. The design, operating characteristics and field application of these regulators is described. The regulators are small in size, low in cost, very low in power dissipation, reliable and allow considerable flexibility in system design.

  9. Silicon-on-insulator-based high-voltage, high-temperature integrated circuit gate driver for silicon carbide-based power field effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Tolbert, Leon M [ORNL; Huque, Mohammad A [ORNL; Blalock, Benjamin J [ORNL; Islam, Syed K [ORNL

    2010-01-01

    Silicon carbide (SiC)-based field effect transistors (FETs) are gaining popularity as switching elements in power electronic circuits designed for high-temperature environments like hybrid electric vehicle, aircraft, well logging, geothermal power generation etc. Like any other power switches, SiC-based power devices also need gate driver circuits to interface them with the logic units. The placement of the gate driver circuit next to the power switch is optimal for minimising system complexity. Successful operation of the gate driver circuit in a harsh environment, especially with minimal or no heat sink and without liquid cooling, can increase the power-to-volume ratio as well as the power-to-weight ratio for power conversion modules such as a DC-DC converter, inverter etc. A silicon-on-insulator (SOI)-based high-voltage, high-temperature integrated circuit (IC) gate driver for SiC power FETs has been designed and fabricated using a commercially available 0.8--m, 2-poly and 3-metal bipolar-complementary metal oxide semiconductor (CMOS)-double diffused metal oxide semiconductor (DMOS) process. The prototype circuit-s maximum gate drive supply can be 40-V with peak 2.3-A sourcing/sinking current driving capability. Owing to the wide driving range, this gate driver IC can be used to drive a wide variety of SiC FET switches (both normally OFF metal oxide semiconductor field effect transistor (MOSFET) and normally ON junction field effect transistor (JFET)). The switching frequency is 20-kHz and the duty cycle can be varied from 0 to 100-. The circuit has been successfully tested with SiC power MOSFETs and JFETs without any heat sink and cooling mechanism. During these tests, SiC switches were kept at room temperature and ambient temperature of the driver circuit was increased to 200-C. The circuit underwent numerous temperature cycles with negligible performance degradation.

  10. Picosecond all-optical switching in hydrogenated amorphous silicon microring resonators

    CERN Document Server

    Pelc, Jason S; Vo, Sonny; Santori, Charles; Fattal, David A; Beausoleil, Raymond G

    2014-01-01

    We utilize cross-phase modulation to observe all-optical switching in microring resonators fabricated with hydrogenated amorphous silicon (a-Si:H). Using 2.7-ps pulses from a mode-locked fiber laser in the telecom C-band, we observe optical switching of a cw telecom-band probe with full-width at half-maximum switching times of 14.8 ps, using approximately 720 fJ of energy deposited in the microring. In comparison with telecom-band optical switching in crystalline silicon microrings, a-Si:H exhibits substantially higher switching speeds due to reduced impact of free-carrier processes.

  11. Experimental Demonstration of 7 Tb/s Switching Using Novel Silicon Photonic Integrated Circuit

    DEFF Research Database (Denmark)

    Ding, Yunhong; Kamchevska, Valerija; Dalgaard, Kjeld;

    2016-01-01

    We demonstrate BER performance <10^-9 for a 1 Tb/s/core transmission over 7-core fiber and SDM switching using a novel silicon photonic integrated circuit composed of a 7x7 fiber switch and low loss SDM couplers.......We demonstrate BER performance integrated circuit composed of a 7x7 fiber switch and low loss SDM couplers....

  12. Methods For The Minimization Of Actuation Voltage In MEMS Switch

    Directory of Open Access Journals (Sweden)

    Jaspreet M. Hora,

    2014-03-01

    Full Text Available MEMS (Micro-Electro-Mechanical Systems is the Combination of mechanical functions such as sensing, moving, heating and electrical functions such as switching on the same chip using micro fabrication technology. The term MEMS refers to a collection of microsensors and actuators which can sense its environment and have the ability to react to changes in that environment with the use of a microcircuit control. These micros witches have two major design groups: capacitive (Metal-Insulator-Metal and resistive (Metal-To-Metal. In the capacitive design of a microswitch it refers the RF signal is shorted to ground by a variable capacitor. In the Resistive design switch operates by creating an open or short in the transmission line. This paper reviews the progress in MEMS applications from a device perspective. It includes the designing of cantilever switch and will tell about the important device parameters that are highlighted, as they have significant contributions to the performance of the final products in which the devices are used. The challenges and statuses of these MEMS devices are discussed

  13. Direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify the design, increase...... efficiency, reduce the product volume and lower its cost. As an example, the principle of operation and the measurements made on a direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp are presented....

  14. High voltage conversion ratio, switched C & L cells, step-down DC-DC converter

    DEFF Research Database (Denmark)

    Pelan, Ovidiu; Muntean, Nicolae; Cornea, Octavian;

    2013-01-01

    The paper presents a high voltage conversion ratio DC-DC step-down topology obtained from a classical buck converter associated with an input switched-capacitor cell and an output switched-inductor cell. Analytical descriptions, the voltage and current limits of the main components are synthesized...... in a comparative form, related to the classical buck structure, in order to emphasis the advantages of the proposed converter. Digital simulations and experimental results obtained with a built prototype are compared. From the first evaluation, the proposed converter is expected to be effectively used at input...

  15. A zero-voltage switching technique for minimizing the current-source power of implanted stimulators.

    Science.gov (United States)

    Çilingiroğlu, Uğur; İpek, Sercan

    2013-08-01

    The current-source power of an implanted stimulator is reduced almost to the theoretical minimum by driving the electrodes directly from the secondary port of the inductive link with a dedicated zero-voltage switching power supply. A feedback loop confined to the secondary of the inductive link adjusts the timing and conduction angle of switching to provide just the right amount of supply voltage needed for keeping the current-source voltage constant at or slightly above the compliance limit. Since drive is based on current rather than voltage, and supply-voltage update is near real-time, the quality of the current pulses is high regardless of how the electrode impedance evolves during stimulation. By scaling the switching frequency according to power demand, the technique further improves overall power consumption of the stimulator. The technique is implemented with a very simple control circuitry comprising a comparator, a Schmitt trigger and a logic gate of seven devices in addition to an on-chip switch and an off-chip capacitor. The power consumed by the proposed supply circuit itself is no larger than what the linear regulator of a conventional supply typically consumes for the same stimulation current. Still, the sum of supply and current-source power is typically between 20% and 75% of the conventional source power alone. Functionality of the proposed driver is verified experimentally on a proof-of-concept prototype built with 3.3 V devices in a 0.18 μm CMOS technology.

  16. Effect of Grain Size on the Threshold Voltage for Double-Gate Polycrystaline Silicon MOSFET

    Directory of Open Access Journals (Sweden)

    Alka Panwar

    2011-01-01

    Full Text Available The effect of grain size (D on the threshold voltage (Vth for double gate polycrystalline silicon MOSFET is investigated theoretically in terms of grain boundary trap states (NT. It is found that the threshold voltage (Vth increases non-linearly with increasing silicon-oxide thickness (tox for all values of grain size (D. However the threshold voltage is seen to have smaller values for same tox for the larger grains. This may be attributed to the reduction in the number of trap states in the depletion regions on either side of a grain boundary. Finally the dependence of threshold voltage (Vth on various parameters such as the doping concentration, interface trap state density and field penetration from drain to source are explored out. The results of these findings are in good agreement with those available in the literature. For large grain poly silicon MOSFET the threshold voltage is seen to approach the single crystal value.

  17. Design and Development of a Series Switch for High Voltage in RF Heating

    Science.gov (United States)

    Patel, Himanshu K.; Shah, Deep; Thacker, Mauli; Shah, Atman

    2013-02-01

    Plasma is the fourth state of matter. To sustain plasma in its ionic form very high temperature is essential. RF heating systems are used to provide the required temperature. Arching phenomenon in these systems can cause enormous damage to the RF tube. Heavy current flows across the anode-cathode junction, which need to be suppressed in minimal time for its protection. Fast-switching circuit breakers are used to cut-off the load from the supply in cases of arching. The crowbar interrupts the connection between the high voltage power supply (HVPS) and the RF tube for a temporary period between which the series switch has to open. The crowbar shunts the current across the load but in the process leads to short circuiting the HVPS. Thus, to protect the load as well as the HVPS a series switch is necessary. This paper presents the design and development of high voltage Series Switch for the high power switching applications. Fiber optic based Optimum triggering scheme is designed and tested to restrict the time delay well within the stipulated limits. The design is well supported with the experimental results for the whole set-up along with the series switch at various voltage level before its approval for operation at 5.2 kV.

  18. Phase diagrams and switching of voltage and magnetic field in dilute magnetic semiconductor nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Escobedo, R. [Departamento de Matematica Aplicada y Ciencias de la Computacion, Universidad de Cantabria, 39005 Santander (Spain); Carretero, M.; Bonilla, L.L. [G. Millan Institute, Fluid Dynamics, Nanoscience and Industrial Maths., Universidad Carlos III de Madrid, 28911 Leganes (Spain); Unidad Asociada al Instituto de Ciencia de Materiales, CSIC, 28049 Cantoblanco, Madrid (Spain); Platero, G. [Instituto de Ciencia de Materiales, CSIC, 28049 Cantoblanco, Madrid (Spain)

    2010-04-15

    The response of an n-doped dc voltage biased II-VI multi-quantum well dilute magnetic semiconductor nanostructure having its first well doped with magnetic (Mn) impurities is analyzed by sweeping wide ranges of both the voltage and the Zeeman level splitting induced by an external magnetic field. The level splitting versus voltage phase diagram shows regions of stable self-sustained current oscillations immersed in a region of stable stationary states. Transitions between stationary states and self-sustained current oscillations are systematically analyzed by both voltage and level splitting abrupt switching. Sudden voltage or/and magnetic field changes may switch on current oscillations from an initial stationary state, and reciprocally, current oscillations may disappear after sudden changes of voltage or/and magnetic field changes into the stable stationary states region. The results show how to design such a device to operate as a spin injector and a spin oscillator by tuning the Zeeman splitting (through the applied external magnetic field), the applied voltage and the sample configuration parameters (doping density, barrier and well widths, etc.) to select the desired stationary or oscillatory behavior. Phase diagram of Zeeman level splitting {delta} vs. dimensionless applied voltage {phi} for N = 10 QWs. White region: stable stationary states; black: stable self-sustained current oscillations. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. A new analytical model of high voltage silicon on insulator (SOI) thin film devices

    Institute of Scientific and Technical Information of China (English)

    Hu Sheng-Dong; Zhang Bo; Li Zhao-Ji

    2009-01-01

    A new analytical model of high voltage silicon on insulator (SOI) thin film devices is proposed, and a formula of silicon critical electric field is derived as a function of silicon film thickness by solving a 2D Poisson equation from an effective ionization rate, with a threshold energy taken into account for electron multiplying. Unlike a conventional silicon critical electric field that is constant and independent of silicon film thickness, the proposed silicon critical electric field increases sharply with silicon film thickness decreasing especially in the case of thin films, and can come to 141 V/μm at a film thickness of 0.1 μm which is much larger than the normal value of about 30 V/μm. From the proposed formula of silicon critical electric field, the expressions of dielectric layer electric field and vertical breakdown voltage (VB,V) are obtained. Based on the model, an ultra thin film can be used to enhance dielectric layer electric field and so increase vertical breakdown voltage for SOI devices because of its high silicon critical electric field, and with a dielectric layer thickness of 2 μm the vertical breakdown voltages reach 852 and 300V for the silicon film thicknesses of 0.1 and 5μm, respectively. In addition, a relation between dielectric layer thickness and silicon film thickness is obtained, indicating a minimum vertical breakdown voltage that should be avoided when an SOI device is designed. 2D simulated results and some experimental results are in good agreement with analytical results.

  20. Sub-band transport mechanism and switching properties for resistive switching nonvolatile memories with structure of silver/aluminum oxide/p-type silicon

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yanhong; Li, La; Wang, Song; Gao, Ping; Pan, Lujun; Zhang, Jialiang [School of Physics and Optoelectronic Engineering, Dalian University of Technology, No. 2 Linggong Road, Ganjingzi District, Dalian 116024 (China); Zhou, Peng [Department of Microelectronics, State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433 (China); Li, Jinhua; Weng, Zhankun [Center for Nano Metrology and Manufacturing Technologies and International Joint Research Center for Nanophotonics and Biophotonics, Changchun University of Science and Technology, Changchun 130022 (China)

    2015-02-09

    In this paper, we discuss a model of sub-band in resistive switching nonvolatile memories with a structure of silver/aluminum oxide/p-type silicon (Ag/Al{sub x}O{sub y}/p-Si), in which the sub-band is formed by overlapping of wave functions of electron-occupied oxygen vacancies in Al{sub x}O{sub y} layer deposited by atomic layer deposition technology. The switching processes exhibit the characteristics of the bipolarity, discreteness, and no need of forming process, all of which are discussed deeply based on the model of sub-band. The relationships between the SET voltages and distribution of trap levels are analyzed qualitatively. The semiconductor-like behaviors of ON-state resistance affirm the sub-band transport mechanism instead of the metal filament mechanism.

  1. Research on Mechanism of Overcurrent and Overvoltage When Contactless Tap Changer Switch Regulates Voltage on Load

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Analyzes the mechanism of overvoltage when contactless tap changer switch which is applied in distributing transformer converted directly.When the device convert the tap-off,it employs the way that the SSR is switched on when voltage through zero and switched off when current through zero.But in the experiment we found that overvoltage will occur in the process of changing tap changer.The paper illustrates the mechanism of overvoltage in theory by analyzing the equivalent circuit and using analytic method of transition process.

  2. Magneto-optical switch with amorphous silicon waveguides on magneto-optical garnet

    Science.gov (United States)

    Ishida, Eiichi; Miura, Kengo; Shoji, Yuya; Mizumoto, Tetsuya; Nishiyama, Nobuhiko; Arai, Shigehisa

    2016-08-01

    We fabricated a magneto-optical (MO) switch with a hydrogenated amorphous silicon waveguide on an MO garnet. The switch is composed of a 2 × 2 Mach-Zehnder interferometer (MZI). The switch state is controlled by an MO phase shift through a magnetic field generated by a current flowing in an electrode located on the MZI. The switching operation was successfully demonstrated with an extinction ratio of 11.7 dB at a wavelength of 1550 nm.

  3. Reversible voltage dependent transition of abnormal and normal bipolar resistive switching

    Science.gov (United States)

    Wang, Guangyu; Li, Chen; Chen, Yan; Xia, Yidong; Wu, Di; Xu, Qingyu

    2016-11-01

    Clear understanding the mechanism of resistive switching is the important prerequisite for the realization of high performance nonvolatile resistive random access memory. In this paper, binary metal oxide MoOx layer sandwiched by ITO and Pt electrodes was taken as a model system, reversible transition of abnormal and normal bipolar resistive switching (BRS) in dependence on the maximum voltage was observed. At room temperature, below a critical maximum voltage of 2.6 V, butterfly shaped I-V curves of abnormal BRS has been observed with low resistance state (LRS) to high resistance state (HRS) transition in both polarities and always LRS at zero field. Above 2.6 V, normal BRS was observed, and HRS to LRS transition happened with increasing negative voltage applied. Temperature dependent I-V measurements showed that the critical maximum voltage increased with decreasing temperature, suggesting the thermal activated motion of oxygen vacancies. Abnormal BRS has been explained by the partial compensation of electric field from the induced dipoles opposite to the applied voltage, which has been demonstrated by the clear amplitude-voltage and phase-voltage hysteresis loops observed by piezoelectric force microscopy. The normal BRS was due to the barrier modification at Pt/MoOx interface by the accumulation and depletion of oxygen vacancies.

  4. Built-in voltage of a silicon p-n junction having a heavily doped region

    Science.gov (United States)

    Sinha, Amitabha

    1984-01-01

    An analysis of the built-in voltage of a silicon p-n junction has been done, taking into account the band-gap narrowing effects in the heavily doped region. It has been observed that much lower values of built-in voltage are obtained when heavy doping effects are considered. Also, the magnitude of built-in voltage decreases when the temperature of the p-n junction is increased.

  5. A Voltage Doubler Circuit to Extend the Soft-switching Range of Dual Active Bridge Converters

    DEFF Research Database (Denmark)

    Qin, Zian; Shen, Yanfeng; Wang, Huai;

    2017-01-01

    A voltage doubler circuit is realized to extend the soft-switching range of Dual Active Bridge (DAB) converters. No extra hardware is added to the DAB to form this circuit, since it is composed of the dc blocking capacitor and the low side full bridge converter, which already exist in DAB. With t...

  6. Assumption or Fact? Line-to-Neutral Voltage Expression in an Unbalanced 3-Phase Circuit during Inverter Switching

    Science.gov (United States)

    Masrur, M. A.

    2009-01-01

    This paper discusses the situation in a 3-phase motor or any other 3-phase system operating under unbalanced operating conditions caused by an open fault in an inverter switch. A dc voltage source is assumed as the input to the inverter, and under faulty conditions of the inverter switch, the actual voltage applied between the line to neutral…

  7. High-speed 2×2 silicon-based electro-optic switch with nanosecond switch time

    Institute of Scientific and Technical Information of China (English)

    Xu Xue-Jun; Chen Shao-Wu; Xu Hai-Hua; Sun Yang; Yu Yu-De; Yu Jin-Zhong; Wang Qi-Ming

    2009-01-01

    A 2 × 2 electro-optic switch is experimentally demonstrated using the optical structure of a Mach-Zehnder interferometer (MZI) based on a submicron rib waveguide and the electrical structure of a PIN diode on silicon-on-insulator (SOI). The switch behaviour is achieved through the plasma dispersion effect of silicon. The device has a modulation arm of 1 mm in length and cross-section of 400 nm×340 nm. The measurement results show that the switch has a VπLπ figure of merit of 0.145 V.cm and the extinction ratios of two output ports and cross talk are 40 dB,28 dB and -28 dB,respectively. A 3 dB modulation bandwidth of 90 MHz and a switch time of 6.8 ns for the rise edge and 2.7 ns for the fall edge axe also demonstrated.

  8. Diagnosis of stator faults in induction motor based on zero sequence voltage after switch-off

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To improve the accuracy of the stator winding fault diagnosis in induction motor, a new diagnostic method based on the Hilbert-Huang transform (HHT) was proposed. The ratio of fundamental zero sequence voltage to positive sequence voltage after switch-offwas selected as the stator fault characteristic, which could effectively avoid the influence of the supply unbalance and the load fluctuation, and directly represent the asymmetry in the stator. Using the empirical mode decomposition (EMD) based on HHT, the zero sequence voltage after switch-off was decomposed and the fundamental component was extracted. Then, the fault characteristic can be acquired. Experimental results on a 4-kW induction motor demonstrate the feasibility and effectiveness of this method.

  9. Switch-mode High Voltage Drivers for Dielectric Electro Active Polymer (DEAP) Incremental Actuators

    DEFF Research Database (Denmark)

    Thummala, Prasanth

    , a new bidirectional flyback converter topology with multiple series connected outputs is proposed. A theoretical comparison showed that the proposed converter could improve the overall energy efficiency, lower the cost and reduce the volume of high voltage driver. Key words: high voltage, switch...... operation, and low power consumption. DEAP actuators require very high voltage (2-2.5 kV) to fully elongate them. In general, the elongation or stroke length of a DEAP actuator is of the order of mm. DEAP actuators can be configured to provide incremental motion, thus overcoming the inherent size......-to-stroke implications of conventional linear actuators, where the stroke is limited by their size. In incremental mode, DEAP actuators are several orders of magnitude shorter in their length compared to the stroke/elongation they provide. The dissertation presents design, control and implementation of switch-mode high...

  10. A dual VCDL DLL based gate driver for zero-voltage-switching DC-DC converter

    Science.gov (United States)

    Xin, Tian; Xiangxin, Liu; Wenhong, Li

    2010-07-01

    This paper presents a dual voltage-controlled-delay-line (VCDL) delay-lock-loop (DLL) based gate driver for a zero-voltage-switching (ZVS) DC-DC converter. Using the delay difference of two VCDLs for the dead time control, the dual VCDL DLL is able to implement ZVS control with high accuracy while keeping good linearity performance of the DLL and low power consumption. The design is implemented in the CSM 2P4M 0.35 μm CMOS process. The measurement results indicate that an efficiency improvement of 2%-4% is achieved over the load current range from 100 to 600 mA at 4 MHz switching frequency with 3.3 V input and 1.3 V output voltage.

  11. A dual VCDL DLL based gate driver for zero-voltage-switching DC-DC converter

    Energy Technology Data Exchange (ETDEWEB)

    Tian Xin; Liu Xiangxin; Li Wenhong, E-mail: wenhongli@fudan.edu.c [State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

    2010-07-15

    This paper presents a dual voltage-controlled-delay-line (VCDL) delay-lock-loop (DLL) based gate driver for a zero-voltage-switching (ZVS) DC-DC converter. Using the delay difference of two VCDLs for the dead time control, the dual VCDL DLL is able to implement ZVS control with high accuracy while keeping good linearity performance of the DLL and low power consumption. The design is implemented in the CSM 2P4M 0.35 {mu}m CMOS process. The measurement results indicate that an efficiency improvement of 2%-4% is achieved over the load current range from 100 to 600 mA at 4 MHz switching frequency with 3.3 V input and 1.3 V output voltage.

  12. Control of Switching Characteristics of Silicon-based Semiconductor Diode Using High Energy Linear Accelerator

    Directory of Open Access Journals (Sweden)

    N. Harihara Krishnan

    2013-05-01

    Full Text Available This paper reports control of switching characteristics of silicon-based semiconductor diode using electron beam produced using linear accelerator. Conventionally, p-n junction chips of diode are exposed to gamma rays from a radioactive source or electron beam from a microtron, depending upon the required level of correction. High energy linear accelerators featuring simultaneous exposure of multiple chips are recent advancements in radiation technology. The paper presents the results of the radiation process using a 10 MeV linear accelerator as applied in industrial manufacturing of a high voltage diode (2600 V. The achieved values of reverse recovery time were found to be within the design limits. The suitability of the new process was verified by constructing the trade-off curve between the switching and conduction parameters of the diode for the complete range using large number of experimental samples. The paper summarizes the advantages of the new process over the conventional methods specifically with reference to industrial requirements. The developed process has been successfully implemented in semiconductor manufacturing.

  13. Silicon photonic switch technology for optical networks in telecom and datacom areas

    Science.gov (United States)

    Nakamura, Shigeru; Yanagimachi, Shigeyuki; Takeshita, Hitoshi; Tajima, Akio

    2017-01-01

    As a promising platform technology for optical switches, silicon photonics is recently attracting much attention. In this paper, we demonstrate compact 8 × 8 silicon photonic switch modules with low loss, low polarization sensitivity, and low cross-talk properties. An optical circuit including 152 thermo-optical switch elements and spot size converters were formed within a silicon chip size of 12 mm × 14 mm. The developed module where a silicon photonic chip was assembled with a fiber array showed about 6-dB average excess optical loss, including optical coupling loss, on all 64 paths of the 8 × 8 optical switch. Measured polarization dependent loss was about 0.6 dB on average over 64 paths and cross-talk was less than -35 dB. These optical switch modules are intended for applying to ROADMs in telecom optical networks, but, the port count extensibility using multiple compact modules and the faster switching capability of the optical switch are also useful for datacenter applications where hybrid network scheme with electronic packet switches and optical circuit switches is intensively investigated.

  14. Voltage Sag Mitigation Using Pulse Width Modulation Switched Autotransformer through Matlab Simulation

    Directory of Open Access Journals (Sweden)

    P. Shyam Kiran

    2014-04-01

    Full Text Available In this paper, a new voltage sag compensator for critical loads in electrical distribution system discussed. The proposed scheme employs a Pulse width modulation ac-ac converter along with a auto transformer. During a disturbance such as voltage sag, the proposed scheme supplies the missing voltage and helps in maintaining the rated voltage at the terminals of the critical load. Under normal condition the approach work in bypass mode and delivering utility power directly to load. The proposed system has less number of switching devices and has good compensating capability in comparison to commonly used compensators. Simulation analysis of three-phase compensator is performed in MATLAB/SIMULINK and performance analysis of the system is presented for various levels of sag and swell.

  15. Powerful diode nanosecond current opening switch made of p-silicon ( p-SOS)

    Science.gov (United States)

    Grekhov, I. V.; Lyublinskii, A. G.; Belyakova, E. I.

    2016-03-01

    The nanosecond semiconductor diode-based opening switch (SOS-diode) capable of switching currents with densities up to several tens of kiloamperes per cubic centimeter represents a p + p'Nn+ silicon structure fabricated by the deep simultaneous diffusion doping (to about 200 μm) of n-Si by Al and B from one side and P from the other. In the SOS mode, first a short pulse of forward current passes through the diode and then a fast-growing pulse of reverse voltage is applied. A resulting pulse of reverse current carries away injected holes and thereby forms a plasma front in the p' layer, which moves toward the p' N junction. When the hole concentration in the flow exceeds the dopant concentration in the p' layer, a space charge region arises in this layer, the resistivity of the diode increases sharply, and the current switches to a load connected parallel to the diode. Early results concerning an alternative configuration of the SOS diode are presented. Here, the diode was made by the rapid simultaneous diffusion of B and P from the opposite sides of a p-Si wafer to a depth of 60-80 μm. If a short pulse of forward current is passed through such a p + pn + structure and a pulse of reverse voltage is then applied, a plasma front arising in the p + region moves toward the p + p interface through the heavily doped (i.e., low-resistivity) p + region. Having crossed this interface, the front passes into a low-doped region, where the hole concentration in the flow becomes much higher than the dopant concentration and a space charge region causing the current to pass to the load forms at once. It is shown experimentally that, all other things being the same, the time of current breaking in the p-SOS-diode is roughly twice as short as in the conventional n-SOS-diode, switched currents are considerably lower, and the fabrication technique of p-SOS-diodes is much simpler. Ways of optimizing the design of the semiconductor structure of the p-SOS-diode to further raise the

  16. High voltage bulk GaN-based photoconductive switches for pulsed power applications

    Science.gov (United States)

    Leach, J. H.; Metzger, R.; Preble, E. A.; Evans, K. R.

    2013-03-01

    Switches are at the heart of all pulsed power and directed energy systems, which find utility in a number of applications. At present, those applications requiring the highest power levels tend to employ spark-gap switches, but these suffer from relatively high delay-times (~10-8 sec), significant jitter (variation in delay time), and large size. That said, optically-triggered GaN-based photoconductive semiconductor switches (PCSS) offer a suitably small form factor and are a cost-effective, versatile solution in which delay times and jitter can be extremely short. Furthermore, the optical control of the switch means that they are electrically isolated from the environment and from any other system circuitry, making them immune from electrical noise, eliminating the potential for inadvertent switch triggering. Our recent work shows great promise to extend high-voltage GaN-based extrinsic PCSS state-of-the-art performance in terms of subnanosecond response times, low on-resistance, high current carrying capacity and high blocking voltages. We discuss our recent results in this work.

  17. A highly scalable fully non-blocking silicon photonic switch fabric

    CERN Document Server

    Nikolova, Dessislava; Liu, Yang; Rumley, Sebastien; Novack, Ari; Baehr-Jones, Tom; Hochberg, Michael; Bergman, Keren

    2016-01-01

    Large port count spatial optical switches will facilitate flexible and energy efficient data movement in future data communications systems, especially if they are capable of nanosecond-order reconfiguration times. In this work, we demonstrate an 8x8 microring-based silicon photonic switch with software controlled switching. The proposed switch architecture is modular as it assembles multiple identical components with multiplexing/demultiplexing functionalities. The switch is fully non-blocking, has path independent insertion loss, low crosstalk and is straightforward to control. A scalability analysis shows that this architecture can scale to very large port counts. This work represents the first demonstration of real-time firmware controlled switching with silicon photonics devices integrated at the chip scale.

  18. Direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify design, increase efficiency and integration level, reduce product volume and lower its cost. As an example, the principle of operation and the measurements made on a direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp are presented. (au)

  19. Fast switching thyristor applied in nanosecond-pulse high-voltage generator with closed transformer core.

    Science.gov (United States)

    Li, Lee; Bao, Chaobing; Feng, Xibo; Liu, Yunlong; Fochan, Lin

    2013-02-01

    For a compact and reliable nanosecond-pulse high-voltage generator (NPHVG), the specification parameter selection and potential usage of fast controllable state-solid switches have an important bearing on the optimal design. The NPHVG with closed transformer core and fast switching thyristor (FST) was studied in this paper. According to the analysis of T-type circuit, the expressions for the voltages and currents of the primary and secondary windings on the transformer core of NPHVG were deduced, and the theoretical maximum analysis was performed. For NPHVG, the rise-rate of turn-on current (di/dt) across a FST may exceed its transient rating. Both mean and maximum values of di/dt were determined by the leakage inductances of the transformer, and the difference is 1.57 times. The optimum winding ratio is helpful to getting higher voltage output with lower specification FST, especially when the primary and secondary capacitances have been established. The oscillation period analysis can be effectively used to estimate the equivalent leakage inductance. When the core saturation effect was considered, the maximum di/dt estimated from the oscillating period of the primary current is more accurate than one from the oscillating period of the secondary voltage. Although increasing the leakage inductance of NPHVG can decrease di/dt across FST, it may reduce the output peak voltage of the NPHVG.

  20. Silicon-Germanium Voltage-Controlled Oscillator at 105 GHz

    Science.gov (United States)

    Wong, Alden; Larocca, Tim; Chang, M. Frank; Samoska, Lorene A.

    2011-01-01

    A group at UCLA, in collaboration with the Jet Propulsion Laboratory, has designed a voltage-controlled oscillator (VCO) created specifically for a compact, integrated, electronically tunable frequency generator useable for submillimeter- wave science instruments operating in extreme cold environments.

  1. Dynamic magnetization switching and spin wave excitations by voltage-induced torque

    Science.gov (United States)

    Shiota, Yoichi

    2013-03-01

    The effect of electric fields on ultrathin ferromagnetic metal layer is one of the promising approaches for manipulating the spin direction with low-energy consumption, localization, and coherent behavior. Several experimental approaches to realize it have been investigated using ferromagnetic semiconductors, magnetostriction together with piezo-electric materials, multiferroic materials, and ultrathin ferromagnetic layer. In this talk, we will present a dynamic control of spins by voltage-induced torque. We used the magnetic tunnel junctions with ultrathin ferromagnetic layer, which shows voltage-induced perpendicular magnetic anisotropy change. By applying the voltage to the junction, the magnetic easy-axis in the ultrathin ferromagnetic layer changes from in-plane to out-of-plane, which causes a precession of the spins. This precession resulted in a two-way toggle switching by determining an appropriate pulse length. On the other hand, an application of rf-voltage causes an excitation of a uniform spin-wave. Since the precession of spin associates with an oscillation in the resistance of the junction, the applied rf-signal is rectified and produces a dc-voltage. From the spectrum of the dc-voltage as a function of frequency, we could estimate the voltage-induced torque. This research was supported by CREST-JST, G-COE program, and JSPS for the fellowship. Collaborators include T. Nozaki, S. Miwa, F. Bonell, N. Mizuochi, T. Shinjo, and Y. Suzuki.

  2. Breakdown voltage model and structure realization of a thin silicon layer with linear variable doping on a silicon on insulator high voltage device with multiple step field plates

    Institute of Scientific and Technical Information of China (English)

    Qiao Ming; Zhuang Xiang; Wu Li-Juan; Zhang Wen-Tong; Wen Heng-Juan; Zhang Bo; Li Zhao-Ji

    2012-01-01

    Based on the theoretical and experimental investigation of a thin silicon layer (TSL) with linear variable doping (LVD) and further research on the TSL LVD with a multiple step field plate (MSFP),a breakdown voltage (BV) model is proposed and experimentally verified in this paper.With the two-dimensional Poisson equation of the silicon on insulator (SOI) device,the lateral electric field in drift region of the thin silicon layer is assumed to be constant.For the SOI device with LVD in the thin silicon layer,the dependence of the BV on impurity concentration under the drain is investigated by an enhanced dielectric layer field (ENDIF),from which the reduced surface field (RESURF) condition is deduced.The drain in the centre of the device has a good self-isolation effect but the problem of the high voltage interconnection (HVI) line will become serious.The two step field plates including the source field plate and gate field plate can be adopted to shield the HVI adverse effect on the device.Based on this model,the TSL LVD SOI n-channel lateral double-diffused MOSFET (nLDMOS) with MSFP is realized.The experimental breakdown voltage (BV) and specific on-resistance (Ron,sp) of the TSL LVD SOI device are 694 V and 21.3 Ω.mm2 with a drift region length of 60 μm,buried oxide layer of 3 μm,and silicon layer of 0.15 μm,respectively.

  3. Topographical and electrochemical nanoscale imaging of living cells using voltage-switching mode scanning electrochemical microscopy.

    Science.gov (United States)

    Takahashi, Yasufumi; Shevchuk, Andrew I; Novak, Pavel; Babakinejad, Babak; Macpherson, Julie; Unwin, Patrick R; Shiku, Hitoshi; Gorelik, Julia; Klenerman, David; Korchev, Yuri E; Matsue, Tomokazu

    2012-07-17

    We describe voltage-switching mode scanning electrochemical microscopy (VSM-SECM), in which a single SECM tip electrode was used to acquire high-quality topographical and electrochemical images of living cells simultaneously. This was achieved by switching the applied voltage so as to change the faradaic current from a hindered diffusion feedback signal (for distance control and topographical imaging) to the electrochemical flux measurement of interest. This imaging method is robust, and a single nanoscale SECM electrode, which is simple to produce, is used for both topography and activity measurements. In order to minimize the delay at voltage switching, we used pyrolytic carbon nanoelectrodes with 6.5-100 nm radii that rapidly reached a steady-state current, typically in less than 20 ms for the largest electrodes and faster for smaller electrodes. In addition, these carbon nanoelectrodes are suitable for convoluted cell topography imaging because the RG value (ratio of overall probe diameter to active electrode diameter) is typically in the range of 1.5-3.0. We first evaluated the resolution of constant-current mode topography imaging using carbon nanoelectrodes. Next, we performed VSM-SECM measurements to visualize membrane proteins on A431 cells and to detect neurotransmitters from a PC12 cells. We also combined VSM-SECM with surface confocal microscopy to allow simultaneous fluorescence and topographical imaging. VSM-SECM opens up new opportunities in nanoscale chemical mapping at interfaces, and should find wide application in the physical and biological sciences.

  4. Manufacture tolerance analysis and control for a polymer on-silicon Mach-Zehnder-interferometer-based electro-optic switch

    Institute of Scientific and Technical Information of China (English)

    ZHENG Chuan-tao; MA Chun-sheng; YAN Xin; CUI Zhan-chen; ZHANG Da-ming

    2011-01-01

    To enhance the electro-optic (EO) modulation efficiency and realize the impedance-matching, a polymer-on-silicon multi mode interference (MMI) Mach-Zehnder interferometer (MZI) -based electro-optic (EO) switch is designed and optimized.Under the central operation wavelength of 1550 nm, the driving voltages of the designed switch are O and ±1.375 V,respectively, with a short active region length of 5 mm, and the characteristic impedance of the electrode is about 49.6 Ω.The manufacture tolerance is analyzed for instructing the device fabrication. The results show that to realize ideal switching function, high fabrication accuracy on the buffer thickness, core thickness, electrode width and MMI wavegnide width is extremely required, and a small voltage drift of-0.03-0.05 V is also expected for reducing the crosstalk to less than -30 dB.The allowed 3 dB bandwidth is 60 nm, and within this spectrum range, the insertion loss and crosstalk are less than 6.71 dB and -30 dB, respectively.

  5. Large Area Silicon Carbide Vertical JFETs for 1200 V Cascode Switch Operation

    Directory of Open Access Journals (Sweden)

    Victor Veliadis

    2008-01-01

    Full Text Available SiC VJFETs are excellent candidates for reliable high-power/temperature switching as they only use pn junctions in the active device area where the high-electric fields occur. VJFETs do not suffer from forward voltage degradation, exhibit excellent short-circuit performance, and operate at 300°C. 0.19 cm2 1200 V normally-on and 0.15 cm2 low-voltage normally-off VJFETs were fabricated. The 1200-V VJFET outputs 53 A with a forward drain voltage drop of 2 V and a specific onstate resistance of 5.4 mΩ cm2. The low-voltage VJFET outputs 28 A with a forward drain voltage drop of 3.3 V and a specific onstate resistance of 15 mΩ cm2. The 1200-V SiC VJFET was connected in the cascode configuration with two Si MOSFETs and with a low-voltage SiC VJFET to form normally-off power switches. At a forward drain voltage drop of 2.2 V, the SiC/MOSFETs cascode switch outputs 33 A. The all-SiC cascode switch outputs 24 A at a voltage drop of 4.7 V.

  6. A low-voltage high-speed electronic switch based on piezoelectric transduction

    Science.gov (United States)

    Newns, Dennis; Elmegreen, Bruce; Hu Liu, Xiao; Martyna, Glenn

    2012-04-01

    We propose a novel digital switch, the piezoelectronic transistor or PET. Based on properties of known materials, we predict that a nanometer-scale PET can operate at low voltages and relatively high speeds, exceeding the capabilities of any conventional field effect transistor (FET). Depending on the degree to which these attributes can be simultaneously achieved, the device has a broad array of potential applications in digital logic. The PET is a 3-terminal switch in which a gate voltage is applied to a piezoelectric (PE), resulting in expansion compressing a piezoresistive (PR) material comprising the channel, which then undergoes a continuous, reversible insulator-metal transition. The channel becomes conducting in response to the gate voltage. A high piezoelectric coefficient PE, e.g., a relaxor piezoelectric, leads to low voltage operation. Suitable channel materials manifesting a pressure-induced metal-insulator transition can be found amongst rare earth chalcogenides, transition metal oxides, and among others. Mechanical requirements include a high PE/PR area ratio to step up pressure, a rigid surround material to constrain the PE and PR external boundaries normal to the strain axis, and a void space to enable free motion of the component side walls. Using static mechanical modeling and dynamic electro-acoustic simulations, we optimize device structure and materials and predict performance.

  7. Model Predictive Controlled Active NPC Inverter for Voltage Stress Balancing Among the Semiconductor Power Switches

    Science.gov (United States)

    Parvez Akter, Md.; Dah-Chuan Lu, Dylan

    2017-07-01

    This paper presents a model predictive controlled three-level three-phase active neutral-point-clamped (ANPC) inverter for distributing the voltage stress among the semiconductor power switches as well as balancing the neutral-point voltage. The model predictive control (MPC) concept uses the discrete variables and effectively operates the ANPC inverter by avoiding any linear controller or modulation techniques. A 4.0 kW three-level three-phase ANPC inverter is developed in the MATLAB/Simulink environment to verify the effectiveness of the proposed MPC scheme. The results confirm that the proposed model predictive controlled ANPC inverter equally distributes the voltage across all the semiconductor power switches and provides lowest THD (0.99%) compared with the traditional NPC inverter. Moreover, the neutral-point voltage balancing is accurately maintained by the proposed MPC algorithm. Furthermore, this MPC concept shows the robustness capability against the parameter uncertainties of the system which is also analyzed by MATLAB/Simulink.

  8. Physicotechnological aspects of low-voltage suppressors developement on the silicon base

    Directory of Open Access Journals (Sweden)

    Rakhmatov A. Z.

    2010-10-01

    Full Text Available It is shown that by arsenic diffusion alloying of silicon plates in conditions of deaerated quartz ampoule the most effective is the use of a compound source in the form of crystal arsenic and silicon powder of boron-implanted silicon grade with base impurity (boron concentration not less than the concentration of base impurity in alloyed silicon plates. The work defines experimental values of surface concentration, proper and effective diffusion coefficients that fit diffision conditions of As inside ampoule for 2 h at temperature 1423 K and pressure of As steams of 2·105 Pa. The received results are of interest in designing and producing of low-voltage (less than 7 V suppressors on the silicon base.

  9. On-chip wavelength switch based on thermally tunable discrete four-wave mixing in a silicon waveguide

    DEFF Research Database (Denmark)

    Pu, Minhao; Chen, Yaohui; Hu, Hao

    2014-01-01

    An on-chip wavelength switch is proposed based on discrete four-wave mixing in a silicon waveguide. Switching operation can be realized by thermal tuning the waveguide dispersion. We also discuss optimal dimension design concerning device performances.......An on-chip wavelength switch is proposed based on discrete four-wave mixing in a silicon waveguide. Switching operation can be realized by thermal tuning the waveguide dispersion. We also discuss optimal dimension design concerning device performances....

  10. A 4 × 4 Strictly Nonblocking Silicon-on-Insulator Thermo-Optic Switch Matrix

    Institute of Scientific and Technical Information of China (English)

    YANG Di; LI Yan-Ping; CHEN Shao-Wu; YU Jin-Zhong

    2005-01-01

    @@ A 4 × 4 strictly nonblocking thermo-optic switch matrix implemented with a 2 × 2 Mach-Zehnder switch unit was fabricated in silicon-on-insulator wafer. Insertion losses of the shortest and the longest path in the device are about 14.8dB and 19.2dB, respectively. The device presents a very low loss dependent on wavelength. For one switch unit, the power consumption needed for operation is measured to be 0.270 W-0.288 W and the switching time is about 13 ± 1μs.

  11. Fabrication of Thermo-Optic Switch in Silicon-on-Insulator

    Institute of Scientific and Technical Information of China (English)

    王章涛; 夏金松; 樊中朝; 陈少武; 余金中

    2003-01-01

    Silicon-on-insulator technology has been used to fabricate 2 × 2 thermo-optic switches. The switch shows crosstalk of-23.4 dB and extinction ratio of 18.1 dB in the bar-state. The switching speed is less than 30 μs and the power consumption is about 420mW. The measured excess loss is 1.8 dB. These merits make the switch more attractive for applications in wavelength division multiplexing.

  12. Novel design of high voltage pulse source for efficient dielectric barrier discharge generation by using silicon diodes for alternating current

    Science.gov (United States)

    Truong, Hoa Thi; Hayashi, Misaki; Uesugi, Yoshihiko; Tanaka, Yasunori; Ishijima, Tatsuo

    2017-06-01

    This work focuses on design, construction, and optimization of configuration of a novel high voltage pulse power source for large-scale dielectric barrier discharge (DBD) generation. The pulses were generated by using the high-speed switching characteristic of an inexpensive device called silicon diodes for alternating current and the self-terminated characteristic of DBD. The operation started to be powered by a primary DC low voltage power supply flexibly equipped with a commercial DC power supply, or a battery, or DC output of an independent photovoltaic system without transformer employment. This flexible connection to different types of primary power supply could provide a promising solution for the application of DBD, especially in the area without power grid connection. The simple modular structure, non-control requirement, transformer elimination, and a minimum number of levels in voltage conversion could lead to a reduction in size, weight, simple maintenance, low cost of installation, and high scalability of a DBD generator. The performance of this pulse source has been validated by a load of resistor. A good agreement between theoretically estimated and experimentally measured responses has been achieved. The pulse source has also been successfully applied for an efficient DBD plasma generation.

  13. Voltage-controlling mechanisms in low-resistivity silicon solar cells - A unified approach

    Science.gov (United States)

    Weizer, V. G.; Swartz, C. K.; Hart, R. E.; Godlewski, M. P.

    1986-01-01

    An experimental technique is used to determine the relative values of the base and emitter components of the dark saturation current of six types of high-voltage low-resistivity silicon solar cells. One of the surprising findings is the suggestion that the magnitude of the minority-carrier mobility may be process-dependent.

  14. Charge collection and capacitance-voltage analysis in irradiated n-type magnetic Czochralski silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Petterson, M.K.; Sadrozinski, H.F.-W.; Betancourt, C. [SCIPP UC Santa Cruz, 1156 High Street, 95064 CA (United States); Bruzzi, M. [INFN, Dipartimento di Energetica, Universita di Firenze, via S. Marta 3, 50139 Florence (Italy)], E-mail: mara.bruzzi@unifi.it; Scaringella, M.; Tosi, C.; Macchiolo, A. [INFN, Dipartimento di Energetica, Universita di Firenze, via S. Marta 3, 50139 Florence (Italy); Manna, N.; Creanza, D. [Universita di Bari (Italy); Boscardin, M.; Piemonte, C.; Zorzi, N. [ITC, IRST, Povo, Trento (Italy); Borrello, L.; Messineo, A. [INFN Pisa (Italy); Dalla Betta, G.F. [Universita di Trento (Italy)

    2007-12-11

    The depletion depth of irradiated n-type silicon microstrip detectors can be inferred from both the reciprocal capacitance and from the amount of collected charge. Capacitance voltage (C-V) measurements at different frequencies and temperatures are being compared with the bias voltage dependence of the charge collection on an irradiated n-type magnetic Czochralski silicon detector. Good agreement between the reciprocal capacitance and the median collected charge is found when the frequency of the C-V measurement is selected such that it scales with the temperature dependence of the leakage current. Measuring C-V characteristics at prescribed combinations of temperature and frequency allows then a realistic estimate of the depletion characteristics of irradiated silicon strip detectors based on C-V data alone.

  15. Novel Step-Up DC/DC Converter with No Right Half Plane Zero and Reduced Switched Voltage Stress Characteristics

    DEFF Research Database (Denmark)

    Mostaan, Ali; Alizadeh, Ebrahim; Soltani, Mohsen

    2014-01-01

    Novel step-up DC/DC converter is introduced in this paper. This converter is realized with adding the switched capacitor voltage multiplier cell to the three switch step-down DC/DC converter that has been proposed in the literature. The proposed converter is analyzed in the steady state and the v...

  16. A scalable silicon photonic chip-scale optical switch for high performance computing systems.

    Science.gov (United States)

    Yu, Runxiang; Cheung, Stanley; Li, Yuliang; Okamoto, Katsunari; Proietti, Roberto; Yin, Yawei; Yoo, S J B

    2013-12-30

    This paper discusses the architecture and provides performance studies of a silicon photonic chip-scale optical switch for scalable interconnect network in high performance computing systems. The proposed switch exploits optical wavelength parallelism and wavelength routing characteristics of an Arrayed Waveguide Grating Router (AWGR) to allow contention resolution in the wavelength domain. Simulation results from a cycle-accurate network simulator indicate that, even with only two transmitter/receiver pairs per node, the switch exhibits lower end-to-end latency and higher throughput at high (>90%) input loads compared with electronic switches. On the device integration level, we propose to integrate all the components (ring modulators, photodetectors and AWGR) on a CMOS-compatible silicon photonic platform to ensure a compact, energy efficient and cost-effective device. We successfully demonstrate proof-of-concept routing functions on an 8 × 8 prototype fabricated using foundry services provided by OpSIS-IME.

  17. Fast and efficient silicon thermo-optic switching based on reverse breakdown of pn junction.

    Science.gov (United States)

    Li, Xianyao; Xu, Hao; Xiao, Xi; Li, Zhiyong; Yu, Yude; Yu, Jinzhong

    2014-02-15

    We propose and demonstrate a fast and efficient silicon thermo-optic switch based on reverse breakdown of the pn junction. Benefiting from the direct heating of silicon waveguide by embedding the pn junction into the waveguide center, fast switching with on/off time of 330 and 450 ns and efficient thermal tuning of 0.12  nm/mW for a 20 μm radius microring resonator are achieved, indicating a high figure of merit of only 8.8  mW·μs. The results here show great potential for application in the future optical interconnects.

  18. Current-voltage characteristics in macroporous silicon/SiOx/SnO2:F heterojunctions.

    Science.gov (United States)

    Garcés, Felipe A; Urteaga, Raul; Acquaroli, Leandro N; Koropecki, Roberto R; Arce, Roberto D

    2012-07-25

    We study the electrical characteristics of macroporous silicon/transparent conductor oxide junctions obtained by the deposition of fluorine doped-SnO2 onto macroporous silicon thin films using the spray pyrolysis technique. Macroporous silicon was prepared by the electrochemical anodization of a silicon wafer to produce pore sizes ranging between 0.9 to 1.2 μm in diameter. Scanning electronic microscopy was performed to confirm the pore filling and surface coverage. The transport of charge carriers through the interface was studied by measuring the current-voltage curves in the dark and under illumination. In the best configuration, we obtain a modest open-circuit voltage of about 70 mV and a short-circuit current of 3.5 mA/cm2 at an illumination of 110 mW/cm2. In order to analyze the effects of the illumination on the electrical properties of the junction, we proposed a model of two opposing diodes, each one associated with an independent current source. We obtain a good accordance between the experimental data and the model. The current-voltage curves in illuminated conditions are well fitted with the same parameters obtained in the dark where only the photocurrent intensities in the diodes are free parameters.

  19. Soft switching (ZVZCS) high current, low voltage modular power converter (13 kA, 16 V)

    CERN Document Server

    Bordry, Frederick; Thiesen, H

    2001-01-01

    The Large Hadron Collider (LHC) is the next accelerator being constructed at the European Laboratory for Particle Physics (CERN). The superconducting LHC particle accelerator requires high currents (13 kA) and relatively low voltages (16 V) for its magnets. This paper describes the development and the production of a (13 kA, 16 V) power converter. The converter is made with a modular concept with five current sources (3.25 kA, 16 V) in parallel. The 3.25 kA sources are built as plug-in modules: a diode rectifier on the AC mains, a zero voltage zero current switching (ZVZCS) inverter working at 25 k Hz and an output stage. The obtained performance is presented and discussed. (6 refs).

  20. Fully on-chip switched capacitor NMOS low dropout voltage regulator

    CERN Document Server

    Camacho, D; Camacho, Daniel; Moreira, Paulo

    2010-01-01

    This paper presents a 1.5 V 50 mA low dropout voltage (LDO) regulator using an NMOS transistor as the output pass element. Continuous time,operation of the LDO is achieved using a new switched floating capacitor scheme that raises the gate voltage of the pass element. The regulator has a 0.2 V dropout at a 50 mA load and is stable for a wide load current range with loading capacitances up to 50 pF. The output variation when a full load step is applied is 300 mV and the recovery time is below 0.3 mu s. it is designed in a 0.13 mu m CMOS process with an area of 0.008 mm(2) and its operation does not require any external component.

  1. Electron tunnelling through single azurin molecules can be on/off switched by voltage pulses

    Science.gov (United States)

    Baldacchini, Chiara; Kumar, Vivek; Bizzarri, Anna Rita; Cannistraro, Salvatore

    2015-05-01

    Redox metalloproteins are emerging as promising candidates for future bio-optoelectronic and nano-biomemory devices, and the control of their electron transfer properties through external signals is still a crucial task. Here, we show that a reversible on/off switching of the electron current tunnelling through a single protein can be achieved in azurin protein molecules adsorbed on gold surfaces, by applying appropriate voltage pulses through a scanning tunnelling microscope tip. The observed changes in the hybrid system tunnelling properties are discussed in terms of long-sustained charging of the protein milieu.

  2. Electron tunnelling through single azurin molecules can be on/off switched by voltage pulses

    Energy Technology Data Exchange (ETDEWEB)

    Baldacchini, Chiara [Biophysics and Nanoscience Centre, DEB-CNISM, Università della Tuscia, I-01100 Viterbo (Italy); Institute of Agro-Environmental and Forest Biology, CNR, I-05010 Porano (Italy); Kumar, Vivek; Bizzarri, Anna Rita; Cannistraro, Salvatore, E-mail: cannistr@unitus.it [Biophysics and Nanoscience Centre, DEB-CNISM, Università della Tuscia, I-01100 Viterbo (Italy)

    2015-05-04

    Redox metalloproteins are emerging as promising candidates for future bio-optoelectronic and nano-biomemory devices, and the control of their electron transfer properties through external signals is still a crucial task. Here, we show that a reversible on/off switching of the electron current tunnelling through a single protein can be achieved in azurin protein molecules adsorbed on gold surfaces, by applying appropriate voltage pulses through a scanning tunnelling microscope tip. The observed changes in the hybrid system tunnelling properties are discussed in terms of long-sustained charging of the protein milieu.

  3. Low Voltage Totally Free Flexible RF MEMS Switch With Anti-Stiction System

    CERN Document Server

    Touati, Salim; Kanciurzewski, Alexandre; Robin, Renaud; Rollier, A -S; Millet, Olivier; Segueni, Karim

    2008-01-01

    This paper concerns a new design of RF MEMS switch combined with an innovative process which enable low actuation voltage (<5V) and avoid stiction. First, the structure described with principal design issues, the corresponding anti-stiction system is presented and FEM simulations are done. Then, a short description of the process flow based on two non polymer sacrificial layers. Finally, RF measurements are presented and preliminary experimental protocol and results of anti-stiction validation is detailed. Resulting RF performances are -30dB of isolation and -0.45dB of insertion loss at 10 GHz.

  4. Voltage-Controlled Square/Triangular Wave Generator with Current Conveyors and Switching Diodes

    Directory of Open Access Journals (Sweden)

    Martin Janecek

    2012-12-01

    Full Text Available A novel relaxation oscillator based on integrating the diode-switched currents and Schmitt trigger is presented. It is derived from a known circuit with operational amplifiers where these active elements were replaced by current conveyors. The circuit employs only grounded resistances and capacitance and is suitable for high frequency square and triangular signal generation. Its frequency can be linearly and accurately controlled by voltage that is applied to a high-impedance input. Computer simulation with a model of a manufactured conveyor prototype verifies theoretic assumptions.

  5. The piezoelectronic stress transduction switch for very large-scale integration, low voltage sensor computation, and radio frequency applications

    Science.gov (United States)

    Magdǎu, I.-B.; Liu, X.-H.; Kuroda, M. A.; Shaw, T. M.; Crain, J.; Solomon, P. M.; Newns, D. M.; Martyna, G. J.

    2015-08-01

    The piezoelectronic transduction switch is a device with potential as a post-CMOS transistor due to its predicted multi-GHz, low voltage performance on the VLSI-scale. However, the operating principle of the switch has wider applicability. We use theory and simulation to optimize the device across a wide range of length scales and application spaces and to understand the physics underlying its behavior. We show that the four-terminal VLSI-scale switch can operate at a line voltage of 115 mV while as a low voltage-large area device, ≈200 mV operation at clock speeds of ≈2 GHz can be achieved with a desirable 104 On/Off ratio—ideal for on-board computing in sensors. At yet larger scales, the device is predicted to operate as a fast (≈250 ps) radio frequency (RF) switch exhibiting high cyclability, low On resistance and low Off capacitance, resulting in a robust switch with a RF figure of merit of ≈4 fs. These performance benchmarks cannot be approached with CMOS which has reached fundamental limits. In detail, a combination of finite element modeling and ab initio calculations enables prediction of switching voltages for a given design. A multivariate search method then establishes a set of physics-based design rules, discovering the key factors for each application. The results demonstrate that the piezoelectronic transduction switch can offer fast, low power applications spanning several domains of the information technology infrastructure.

  6. Low-voltage high-speed coupling modulation in silicon racetrack ring resonators.

    Science.gov (United States)

    Yang, Rui; Zhou, Linjie; Zhu, Haike; Chen, Jianping

    2015-11-02

    We demonstrate a low-voltage high-speed modulator based on a silicon racetrack resonator with a tunable Mach-Zehnder interferometer coupler. Both static measurement and dynamic modulation experiment are carried out. The 3-dB electro-optic bandwidth is measured to be >30 GHz beyond the limit by the cavity photon lifetime. A 32 Gb/s on-off keying (OOK) modulation is realized under a peak-to-peak drive voltage as low as 0.4 V, and a 28 Gb/s binary phase-shift-keying (BPSK) modulation is realized with a drive voltage of 3 V. The low drive voltages results in low energy consumptions of ~13.3 fJ/bit and ~1.2 pJ/bit for OOK and BPSK modulations, respectively.

  7. Investigation of leakage current and breakdown voltage in irradiated double-sided 3D silicon sensors

    Science.gov (United States)

    Dalla Betta, G.-F.; Ayllon, N.; Boscardin, M.; Hoeferkamp, M.; Mattiazzo, S.; McDuff, H.; Mendicino, R.; Povoli, M.; Seidel, S.; Sultan, D. M. S.; Zorzi, N.

    2016-09-01

    We report on an experimental study aimed at gaining deeper insight into the leakage current and breakdown voltage of irradiated double-sided 3D silicon sensors from FBK, so as to improve both the design and the fabrication technology for use at future hadron colliders such as the High Luminosity LHC. Several 3D diode samples of different technologies and layout are considered, as well as several irradiations with different particle types. While the leakage current follows the expected linear trend with radiation fluence, the breakdown voltage is found to depend on both the bulk damage and the surface damage, and its values can vary significantly with sensor geometry and process details.

  8. Optimization of silicon-on-insulator based optical switch using tapered waveguides

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Optimiz ed 2×2 switches based on silicon-on-insulator (SOI) were demonstrated. In the design, single mode rib waveguides and multimode interferences (MMIs) are connected by tapered waveguides to reduce the mode coupling loss between the two types of waveguides. The average insertion loss of the switches is about -16.9 dB and the excess loss of one is measured of -1.3 dB. The worst crosstalk is larger than 25 dB. Experimental results indicate that some of the main characteristics of optical switches are improved in the modified design, which is according with theoretic analysis. The novel design can be used to improve the characteristics of optical switch matrixes based on 2×2 switch units.

  9. Laser-triggered high-voltage plasma switching with diffractive optics.

    Science.gov (United States)

    Ekberg, M; Sunesson, A; Bergkvist, M; Gustavsson, A; Isberg, J; Bernhoff, H; Skytt, P; Bengtsson, J; Hård, S; Larsson, M

    2001-06-01

    High-power lasers can be used to induce ionization of gases and thereby enable rapid triggering of electrical discharge devices, potentially faster than any devices based on mechanical or solid-state switching. With diffractive optical elements (DOEs) the laser light can conveniently be directed to positions within the gas so that an electrical discharge between two high-voltage electrodes is triggered reliably and rapidly. Here we report on two different types of DOE used for creating an electrical discharge in pure argon for potential high-voltage applications. One is the diffractive equivalent of a conventional axicon that yields an extended, and continuous, high-intensity focal region between the electrodes. The other is a multiple-focal-distance kinoform--a DOE that is designed to produce a linear array of 20 discrete foci, with high peak intensities, between the electrodes. We show that DOEs enable efficient, rapid switching and may provide increased flexibility in the design of novel electrode configurations.

  10. Resistive switching characteristics and mechanisms in silicon oxide memory devices

    Science.gov (United States)

    Chang, Yao-Feng; Fowler, Burt; Chen, Ying-Chen; Zhou, Fei; Wu, Xiaohan; Chen, Yen-Ting; Wang, Yanzhen; Xue, Fei; Lee, Jack C.

    2016-05-01

    Intrinsic unipolar SiOx-based resistance random access memories (ReRAM) characterization, switching mechanisms, and applications have been investigated. Device structures, material compositions, and electrical characteristics are identified that enable ReRAM cells with high ON/OFF ratio, low static power consumption, low switching power, and high readout-margin using complementary metal-oxide semiconductor transistor (CMOS)-compatible SiOx-based materials. These ideas are combined with the use of horizontal and vertical device structure designs, composition optimization, electrical control, and external factors to help understand resistive switching (RS) mechanisms. Measured temperature effects, pulse response, and carrier transport behaviors lead to compact models of RS mechanisms and energy band diagrams in order to aid the development of computer-aided design for ultralarge-v scale integration. This chapter presents a comprehensive investigation of SiOx-based RS characteristics and mechanisms for the post-CMOS device era.

  11. Design of High-Voltage Switch-Mode Power Amplifier Based on Digital-Controlled Hybrid Multilevel Converter

    Directory of Open Access Journals (Sweden)

    Yanbin Hou

    2016-01-01

    Full Text Available Compared with conventional Class-A, Class-B, and Class-AB amplifiers, Class-D amplifier, also known as switching amplifier, employs pulse width modulation (PWM technology and solid-state switching devices, capable of achieving much higher efficiency. However, PWM-based switching amplifier is usually designed for low-voltage application, offering a maximum output voltage of several hundred Volts. Therefore, a step-up transformer is indispensably adopted in PWM-based Class-D amplifier to produce high-voltage output. In this paper, a switching amplifier without step-up transformer is developed based on digital pulse step modulation (PSM and hybrid multilevel converter. Under the control of input signal, cascaded power converters with separate DC sources operate in PSM switch mode to directly generate high-voltage and high-power output. The relevant topological structure, operating principle, and design scheme are introduced. Finally, a prototype system is built, which can provide power up to 1400 Watts and peak voltage up to ±1700 Volts. And the performance, including efficiency, linearity, and distortion, is evaluated by experimental tests.

  12. Power grid current harmonics mitigation drawn on low voltage rated switching devices with effortless control

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Hugo S.; Anunciada, Victor; Borges, Beatriz V. [Power Electronics Group, Instituto de Telecomunicacoes, Lisbon (Portugal); Instituto Superior Tecnico - Universidade Tecnica de Lisboa, Lisbon (Portugal)

    2010-01-15

    The great majority of the existing hybrid active power filter solutions is normally focused in 3{phi} systems and, in general, concentrates its domain of application in specific loads with deterministic behavior. Because common use grids do not exhibit these characteristics, it is mandatory to develop solutions for more generic scenarios, encouraging the use of less classical hybrid solutions. In fact, due to the widely use of switch mode converters in a great variety of consumer electronics, the problematic of mains current harmonic mitigation is no longer an exclusive matter of 3{phi} systems. The contribution of this paper is to present a shunt hybrid active power filter topology, initially conceived to work in 1{phi} domestic grids, able to operate the inverter at a voltage rate that can be lower than 10% of the mains voltage magnitude, even under nonspecific working conditions. In addition, the results shown in this paper demonstrate that this topology can, without lack of generality, be suitable to medium voltage (1{phi} or 3{phi}) systems. A new control approach for the proposed topology is discussed in this paper. The control method exhibits an extremely simple architecture requiring single point current sensing only, with no need for any kind of reference. Its practical implementation can be fulfilled by using very few, common use, operational amplifiers. The principle of operation, design criteria, simulation predictions and experimental results are presented and discussed. (author)

  13. Design and fabrication of a silicon-based MEMS acceleration switch working lower than 10 g

    Science.gov (United States)

    Hwang, Jeongki; Ryu, Daeho; Park, Chihyun; Jang, Seung-gyo; Lee, Chung-il; Kim, Yong-Kweon

    2017-06-01

    This paper reports a low-g MEMS acceleration switch with threshold acceleration below 10 g. The proposed switch is made of single-crystalline silicon for high thermal stability and stress-free structure. A vertical operation type is adopted to enable fine control of the contact surface during the fabrication process. The switch contains displacement-restricting structures in all directions for impact resistance and is packaged with anodic bonding process. The fabricated switches had an average proof mass, initial gap, and spring constant of 307.38 µg, 6.39 µm, and 3.29 N m-1, respectively. Height profile of the free-hanging proof mass was measured to show that the switch does not suffer from stress problems. In the electrostatic operation test, the contact resistance of the switch was varied with contact force and the minimum value was estimated to be 8.5 Ω. The response time of the switch was measured to be shorter than 1.2 ms. The fabricated switch operated more than 10 000 cycles without failure. For the thermal stability test, the switch was heated at 80 °C for 6 h and the switch operated successfully over 200 times. In the rotation-table experiment, the switch operated at 6.61 g and error analysis was carried out in the consideration of tangential force generated during the rotation-table experiment. From the experimental values, the tangential force was calculated as 2.375 µN and the resulting reduction in the initial switching gap was simulated as 0.32 µm. The reduced threshold acceleration thus was estimated to be 6.62 g, which agrees very well with the measured threshold acceleration value of 6.61 g.

  14. Performance Evaluations of A Single Inductor Type Resonant AC Link Snubber-Assisted Three-Phase Voltage Source Soft-Switching Inverter

    National Research Council Canada - National Science Library

    Yoshida, Masanobu; Hiraki, Eiji; Nakaoka, Mutsuo

    2003-01-01

      This paper presents a novel three-phase voltage source type soft-switching inverter using the main and auxiliary IGBT power module packages in order to reduce their switching power losses as well...

  15. Analysis and design of a high-efficiency zero-voltage-switching step-up DC–DC converter

    Indian Academy of Sciences (India)

    Jae-Won Yang; Hyun-Lark Do

    2013-08-01

    A high-efficiency zero-voltage-switching (ZVS) step-up DC–DC converter is proposed. The proposed ZVS DC–DC step-up converter has fixed switching frequency, simple control, and high efficiency. All power switches can operate with ZVS. The output diodes are under zero-current-switching (ZCS) during turn-off. Due to soft-switching operation of the power switches and output diodes, the proposed ZVS DC–DC converter shows high efficiency. Steady-state analysis of the converter is presented to determine the circuit parameters. A laboratory prototype of the proposed converter is developed, and its experimental results are presented for validation.

  16. Improved Drain Current Saturation and Voltage Gain in Graphene-on-Silicon Field Effect Transistors

    Science.gov (United States)

    Song, Seung Min; Bong, Jae Hoon; Hwang, Wan Sik; Cho, Byung Jin

    2016-05-01

    Graphene devices for radio frequency (RF) applications are of great interest due to their excellent carrier mobility and saturation velocity. However, the insufficient current saturation in graphene field effect transistors (FETs) is a barrier preventing enhancements of the maximum oscillation frequency and voltage gain, both of which should be improved for RF transistors. Achieving a high output resistance is therefore a crucial step for graphene to be utilized in RF applications. In the present study, we report high output resistances and voltage gains in graphene-on-silicon (GoS) FETs. This is achieved by utilizing bare silicon as a supporting substrate without an insulating layer under the graphene. The GoSFETs exhibit a maximum output resistance of 2.5 MΩ•μm, maximum intrinsic voltage gain of 28 dB, and maximum voltage gain of 9 dB. This method opens a new route to overcome the limitations of conventional graphene-on-insulator (GoI) FETs and subsequently brings graphene electronics closer to practical usage.

  17. Serially Connected Micro Amorphous Silicon Solar Cells for Compact High-Voltage Sources

    Directory of Open Access Journals (Sweden)

    Jiyoon Nam

    2016-01-01

    Full Text Available We demonstrate a compact amorphous silicon (a-Si solar module to be used as high-voltage power supply. In comparison with the organic solar module, the main advantages of the a-Si solar module are its compatibility with photolithography techniques and relatively high power conversion efficiency. The open circuit voltage of a-Si solar cells can be easily controlled by serially interconnecting a-Si solar cells. Moreover, the a-Si solar module can be easily patterned by photolithography in any desired shapes with high areal densities. Using the photolithographic technique, we fabricate a compact a-Si solar module with noticeable photovoltaic characteristics as compared with the reported values for high-voltage power supplies.

  18. Design and Implementation of a High Efficiency, Low Component Voltage Stress, Single-Switch High Step-Up Voltage Converter for Vehicular Green Energy Systems

    Directory of Open Access Journals (Sweden)

    Yu-En Wu

    2016-09-01

    Full Text Available In this study, a novel, non-isolated, cascade-type, single-switch, high step-up DC/DC converter was developed for green energy systems. An integrated coupled inductor and voltage lift circuit were applied to simplify the converter structure and satisfy the requirements of high efficiency and high voltage gain ratios. In addition, the proposed structure is controllable with a single switch, which effectively reduces the circuit cost and simplifies the control circuit. With the leakage inductor energy recovery function and active voltage clamp characteristics being present, the circuit yields optimizable conversion efficiency and low component voltage stress. After the operating principles of the proposed structure and characteristics of a steady-state circuit were analyzed, a converter prototype with 450 W, 40 V of input voltage, 400 V of output voltage, and 95% operating efficiency was fabricated. The Renesas MCU RX62T was employed to control the circuits. Experimental results were analyzed to validate the feasibility and effectiveness of the proposed system.

  19. Flexible low-voltage organic integrated circuits with megahertz switching frequencies (Presentation Recording)

    Science.gov (United States)

    Zschieschang, Ute; Takimiya, Kazuo; Zaki, Tarek; Letzkus, Florian; Richter, Harald; Burghartz, Joachim N.; Klauk, Hagen

    2015-09-01

    A process for the fabrication of integrated circuits based on bottom-gate, top-contact organic thin-film transistors (TFTs) with channel lengths as short as 1 µm on flexible plastic substrates has been developed. In this process, all TFT layers (gate electrodes, organic semiconductors, source/drain contacts) are patterned with the help of high-resolution silicon stencil masks, thus eliminating the need for subtractive patterning and avoiding the exposure of the organic semiconductors to potentially harmful organic solvents or resists. The TFTs employ a low-temperature-processed gate dielectric that is sufficiently thin to allow the TFTs and circuits to operate with voltages of about 3 V. Using the vacuum-deposited small-molecule organic semiconductor 2,9-didecyl-dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (C10 DNTT), TFTs with an effective field-effect mobility of 1.2 cm2/Vs, an on/off current ratio of 107, a width-normalized transconductance of 1.2 S/m (with a standard deviation of 6%), and a signal propagation delay (measured in 11-stage ring oscillators) of 420 nsec per stage at a supply voltage of 3 V have been obtained. To our knowledge, this is the first time that megahertz operation has been achieved in flexible organic transistors at supply voltages of less than 10 V. In addition to flexible ring oscillators, we have also demonstrated a 6-bit digital-to-analog converter (DAC) in a binary-weighted current-steering architecture, based on TFTs with a channel length of 4 µm and fabricated on a glass substrate. This DAC has a supply voltage of 3.3 V, a circuit area of 2.6 × 4.6 mm2, and a maximum sampling rate of 100 kS/s.

  20. XMEGA-Based Implementation of Four-Switch, Three-Phase Voltage Source Inverter-Fed Induction Motor Drive

    OpenAIRE

    Abolfazl Halavei Niasar; Ehsan Boloor Kashani

    2013-01-01

    Induction motors offer many advantages tools, and therefore are becoming very popular industrially and commercially. This paper presents the implementation of Xmega microcontroller based PWM inverter controlled of four-switch three phase voltage source inverter (FSTPI) fed induction motor drive. The reduction of the number of power switches from six to four improves the cost effectiveness, volume-compactness and reliability of the three phase inverters in addition to less complexity of contro...

  1. Efficiency Enhancement of a Low-Voltage Automotive Vacuum Cleaner Using a Switched Reluctance Motor

    Directory of Open Access Journals (Sweden)

    Han-Geol Seon

    2016-08-01

    Full Text Available A recent increase in the number of diverse leisure activities and family outdoor activities has increased the need for the automobile-embedded vacuum cleaner. To date, this technology has not been applied in Korea and development efforts are not underway. Many of the existing portable cleaners connecting to the lighter jack of the vehicle use a direct current motor (DC motor. However, they do not have sufficient suction power to satisfy consumers; moreover, they have low durability and efficiency. In this paper, we therefore propose a technology for increasing the efficiency of the low-voltage automobile vacuum cleaner by replacing the existing DC motor with a switched reluctance motor (SRM, which has superior durability and efficiency.

  2. Design of 6-Bit Flash Analog to Digital Converter Using Variable Switching Voltage CMOS Comparator

    Directory of Open Access Journals (Sweden)

    Gulrej Ahmed

    2014-04-01

    Full Text Available This paper presents the design of 6-bit flash analog to digital Converter (ADC using the new variable switching voltage (VSV comparator. In general, Flash ADCs attain the highest conversion speed at the cost of high power consumption. By using the new VSV comparator, the designed 6-bit Flash ADC exhibits significant improvement in terms of power and speed of previously reported Flash ADCs. The simulation result shows that the converter consumes peak power 2.1 mW from a 1.2 V supply and achieves the speed of 1 GHz in a 65nm standard CMOS process. The measurement of maximum differential and integral nonlinearities (DNL and INL of the Flash ADC are 0.3 LSB and 0.6 LSB respectively.

  3. Diagnosis of inverter switch open circuit faults based on neutral point voltage signal analysis

    Directory of Open Access Journals (Sweden)

    Liwei GUO

    Full Text Available Using the current signal to diagnose inverter faults information is apt to be affected by the load, noise and other factors; besides, it requires long diagnosis period with special algorithms and the diagnosis result is easily to be incorrect with no-load or light-load. Focusing on this issue, the logical analysis method is proposed for correlation logical analysis of leg neutral-point voltage and pulse signal to realize the diagnosis of the open circuit faults of inverter switches. The logical expressions of output signals of inverter power tube open-circuit faults is put forward and interrelated hardware circuit design is also elaborated. Delaying the rising edge of inverter power tube's pulse signal can effectively avoid the diagnosis error caused by the power tube's switching on/off. The experiment results show that the method can effectively diagnose the open-circuit faults of single-phase single power tube inverter in real-time and the hardware circuit cost is low, which shows it is effective and feasible.

  4. A single leg switched PWM method for three-phase H-Bridge Voltage Source Converters

    DEFF Research Database (Denmark)

    Senturk, Osman Selcuk; Helle, Lars; Munk-Nielsen, Stig;

    2009-01-01

    This paper proposes a single leg switched or a hybrid PWM (HPWM) method for three-phase three-level H-Bridge Voltage Source Converters (3L-HB-VSCs). By means of the proposed modulation, a 3L-HB-VSC can generate the same output as a three-level neutral point clamped (3L-NPC) VSC with phase...... disposition (PD) PWM provided that the outputs of 3L-HBVSC are isolated by transformers or connected to open winding machines. Thus, the proposed method is called PD-HPWM. Moreover, it is emphasized that 3L-HB-VSC with HPWM utilizes its switches similar to 3L-NPC-VSC. Compared to 3L-NPC-VSCs, 3L......-HB-VSCs (without neutral point clamping diodes) have simpler, more modular, and more reliable 2L circuit structure. Therefore, this method encourages the use of 3L-HB-VSCs in the applications utilizing transformers such as grid-side converters of multi-MW wind turbines. The proposed PWM method's performance...

  5. Development of calcium titanium oxide coated silicon solar cells for enhanced voltage generation capacity

    Directory of Open Access Journals (Sweden)

    Kathirvel K.

    2017-02-01

    Full Text Available Depletion of fossil fuel based energy sources drive the present scenario towards development of solar based alternative energy. Polycrystalline silicon solar cells are preferred due to low cost and abundant availability. However, the power conversion efficiency of polycrystalline silicon is lesser compared to monocrystalline one. The present study aims at analyzing the effect of calcium titanium oxide (CaTiO3 antireflection (AR coating on the power conversion of polycrystalline solar cells. CaTiO3 offers unique characteristics, such as non-radioactive and non-magnetic orthorhombic biaxial structure with bulk density of 3.91 g/cm3. CaTiO3 film deposition on the solar cell substrate has been carried out using Radio Frequency (RF magnetron sputter coating technique under varying time durations (10 min to 45 min. Morphological studies proved the formation of CaTiO3 layer and respective elemental percentages on the coated substrate. Open circuit voltage studies were conducted on bare and coated silicon solar substrates under open and controlled atmospheric conditions. CaTiO3 coated on a solar cell substrate in a deposition time of 30 min showed 8.76 % improvement in the cell voltage compared to the bare solar cell.

  6. Silicon adatom switching and manipulation on Si(111)- 7 x 7

    Energy Technology Data Exchange (ETDEWEB)

    Sagisaka, Keisuke; Fujita, Daisuke [Advanced Nanocharacterization Center, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Luce, Alexander, E-mail: SAGISAKA.Keisuke@nims.go.jp [Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, CA 94720 (United States)

    2010-01-29

    We report on a multiple-state switching behavior in the tip height or tunneling current of scanning tunneling microscopy on the Si(111)- 7 x 7 surface. This switching is caused by displacement of silicon adatoms under the influence of energetic tunneling electrons. When the tip is fixed over a center adatom, five well-defined levels appear in the measured tip height and tunneling current. These levels are attributed to different electronic structures, depending on the configuration of the center adatoms in the unit cell. We also demonstrate manipulations of the center adatoms by controlling the sample bias.

  7. Rad-Hard, Miniaturized, Scalable, High-Voltage Switching Module for Power Applications Rad-Hard, Miniaturized

    Science.gov (United States)

    Adell, Philippe C.; Mojarradi, Mohammad; DelCastillo, Linda Y.; Vo, Tuan A.

    2011-01-01

    A paper discusses the successful development of a miniaturized radiation hardened high-voltage switching module operating at 2.5 kV suitable for space application. The high-voltage architecture was designed, fabricated, and tested using a commercial process that uses a unique combination of 0.25 micrometer CMOS (complementary metal oxide semiconductor) transistors and high-voltage lateral DMOS (diffusion metal oxide semiconductor) device with high breakdown voltage (greater than 650 V). The high-voltage requirements are achieved by stacking a number of DMOS devices within one module, while two modules can be placed in series to achieve higher voltages. Besides the high-voltage requirements, a second generation prototype is currently being developed to provide improved switching capabilities (rise time and fall time for full range of target voltages and currents), the ability to scale the output voltage to a desired value with good accuracy (few percent) up to 10 kV, to cover a wide range of high-voltage applications. In addition, to ensure miniaturization, long life, and high reliability, the assemblies will require intensive high-voltage electrostatic modeling (optimized E-field distribution throughout the module) to complete the proposed packaging approach and test the applicability of using advanced materials in a space-like environment (temperature and pressure) to help prevent potential arcing and corona due to high field regions. Finally, a single-event effect evaluation would have to be performed and single-event mitigation methods implemented at the design and system level or developed to ensure complete radiation hardness of the module.

  8. Quality Assessment of Soft-Switching Based Single-phase Pulse Width Modulated Voltage Source Inverter (PWM VSI

    Directory of Open Access Journals (Sweden)

    Z.A. Jaffery

    2012-10-01

    Full Text Available The authors present the design, simulation and analysis of a single phase voltage source inverter using soft switching techniques. The performance of the inverter has been compared in terms of harmonic contents present in output voltage and current. The research works for a PWM inverter along with a LLCC filter has been investigated. This paper also investigated the performance of the same inverter with a feedback controller with a closed loop feedback path to maintain rated output voltage. This work is helpful for the inverter used in application where high quality ac wave is prime requirement

  9. Determination of economically justified parameters of synchronous disconnection at low-voltage circuit switching via a synchronous vacuum contactor

    Directory of Open Access Journals (Sweden)

    A.V. Verkhola

    2014-04-01

    Full Text Available Dependence of a single switching procedure cost upon the contact opening delay time and delay-time spread is derived for a low-voltage synchronous vacuum contactor. For different cost levels, boundaries of permissible values of delay-time and delay-time spread are specified.

  10. High-voltage electron-microscopical observation of crack-tip dislocations in silicon crystals

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Masaki [Department of Materials Science and Engineering, Kyushu University, 6-10-1 Higashi-ku Fukuoka 812-8581 (Japan)]. E-mail: masaki@dera.zaiko.kyushu-u.ac.jp; Higashida, Kenji [Department of Materials Science and Engineering, Kyushu University, 6-10-1 Higashi-ku Fukuoka 812-8581 (Japan)

    2005-07-25

    Crack-tip dislocations in silicon single crystals were observed by high-voltage electron microscopy. Cracks were introduced into silicon wafers at room temperature by a Vickers indenter. The indented specimens were annealed at 823 K in order to activate dislocation emission from the crack tip under the residual stress due to the indentation. In the specimen without annealing, no dislocations were observed around the crack. On the other hand, in the specimen after the annealing, the aspect of the early stage of dislocation emission was observed, where dislocations were emitted not as a perfect dislocation but as a partial dislocation in the hinge-type plastic zone. Prominent dislocation arrays that were emitted from a crack tip were also observed, and they were found to be of shielding type, which increases the fracture toughness of those crystals.

  11. Factors limiting the open-circuit voltage in microcrystalline silicon solar cells

    Directory of Open Access Journals (Sweden)

    Chatterjee P.

    2011-11-01

    Full Text Available In studying photovoltaic devices made with silicon thin films and considering them according to their grain size, it is curious that as the crystalline fraction increases, the open-circuit voltage (Voc – rather than approaching that of the single-crystal case – shows a decline. To gain an insight into this behavior, observed in hydrogenated microcrystalline silicon (μc-Si:H solar cells prepared under a variety of deposition conditions, we have used a detailed electrical-optical computer modeling program, ASDMP. Two typical μc-Si:H cells with low (~79% and higher (~93% crystalline volume fractions (Fc, deposited in our laboratory and showing this general trend, were modeled. From the parameters extracted by simulation of their experimental current density – voltage and quantum efficiency characteristics, it was inferred that the higher Fc cell has both a higher band gap defect density as well as a lower band gap energy. Our calculations reveal that the proximity of the quasi-Fermi levels to the energy bands in cells based on highly crystallized μc-Si:H (assumed to have a lower band gap, results in both higher free and trapped carrier densities. The trapped hole population, that is particularly high near the P/I interface, results in a strong interface field, a collapse of the field in the volume, and hence a lower open-circuit voltage. Interestingly enough, we were able to fabricate fluorinated μc-Si:H:F cells having 100% crystalline fraction as well as very large grains, that violate the general trend and show a higher Voc. Modeling indicates that this is possible for the latter case, as also for a crystalline silicon PN cell, in spite of a sharply reduced band gap, because the lower effective density of states at the band edges and a sharply reduced gap defect density overcome the effect of the lower band gap.

  12. Voltage-controlled magnetization switching in MRAMs in conjunction with spin-transfer torque and applied magnetic field

    Science.gov (United States)

    Munira, Kamaram; Pandey, Sumeet C.; Kula, Witold; Sandhu, Gurtej S.

    2016-11-01

    Voltage-controlled magnetic anisotropy (VCMA) effect has attracted a significant amount of attention in recent years because of its low cell power consumption during the anisotropy modulation of a thin ferromagnetic film. However, the applied voltage or electric field alone is not enough to completely and reliably reverse the magnetization of the free layer of a magnetic random access memory (MRAM) cell from anti-parallel to parallel configuration or vice versa. An additional symmetry-breaking mechanism needs to be employed to ensure the deterministic writing process. Combinations of voltage-controlled magnetic anisotropy together with spin-transfer torque (STT) and with an applied magnetic field (Happ) were evaluated for switching reliability, time taken to switch with low error rate, and energy consumption during the switching process. In order to get a low write error rate in the MRAM cell with VCMA switching mechanism, a spin-transfer torque current or an applied magnetic field comparable to the critical current and field of the free layer is necessary. In the hybrid processes, the VCMA effect lowers the duration during which the higher power hungry secondary mechanism is in place. Therefore, the total energy consumed during the hybrid writing processes, VCMA + STT or VCMA + Happ, is less than the energy consumed during pure spin-transfer torque or applied magnetic field switching.

  13. Modeling and control of threshold voltage based on pull-in characteristic for micro self-locked switch

    Science.gov (United States)

    Deng, Jufeng; Hao, Yongping; Liu, Shuangjie

    2017-09-01

    Micro self-locked switches (MSS), where execution voltage corresponds to the output signal, are efficient and convenient platforms for sensor applications. The proper functioning of these sensing devices requires driving accurate displacement under execution voltage. In this work, we show how to control the actuating properties of MSSS. This switch comprises microstructures of various shapes with dimensions from 3.5 to 180 μm, which are optimized to encode a desired manufacture deviation by means of mathematical model of threshold voltage. Compared with pull-in voltage, threshold voltage is more easy to control the pull-in instability point by theoretical analysis. With the help of advanced manufacture technology, switch is processed in accordance with the proposed control method. Then, experimental results show that it is better, which have been validated by corresponding experiments. In addition, they can be known from experiments that the manufacturing technology is advanced and feasible, and its high resilience and stably self-locked function can achieve instantaneously sensing.

  14. Capacitance-voltage analysis of a high-k dielectric on silicon

    Institute of Scientific and Technical Information of China (English)

    Davinder Rathee; Sandeep K. Arya; Mukesh Kumar

    2012-01-01

    Device characteristics of TiO2 gate dielectrics deposited by a sol-gel method and DC sputtering method on a P-type silicon wafer are reported.Metal-oxide-semiconductor capacitors with Al as the top electrode were fabricated to study the electrical properties of TiO2 films.The films were physically characterized by using X-ray diffraction,a capacitor voltage measurement,scanning electron microscopy,and by spectroscopy ellipsometry.The XRD and DST-TG indicate the presence of an anatase TiO2 phase in the film.Films deposited at higher temperatures showed better crystallinity.The dielectric constant calculated using the capacitance voltage measurement was found to be 18 and 73 for sputtering and sol-gel samples respectively.The refractive indices of the films were found to be 2.16 for sputtering and 2.42 for sol-gel samples.

  15. Modeling of a Silicon Nanowire pH Sensor with Nanoscale Side Gate Voltage

    Institute of Scientific and Technical Information of China (English)

    Alireza Kargar

    2009-01-01

    A silicon nanowire (Si-NW) sensor for pH detection is presented.The conductance of the device is analytically obtained,demonstrating that the conductance increases with decreasing oxide thickness.To calculate the electrical conductance of the sensor,the diffusion-drift model and nonlinear Poisson-Boltzmann equation are applied.To improve the conductance and sensitivity,a Si-NW sensor with nanoscale side gate voltage is offered and its characteristics are theoretically achieved.It is revealed that the conductance and sensor sensitivity can be enhanced by adding appropriate side gate voltages.This effect is compared to a similar fabricated structure in the literature,which has a wire with a rectangular cross section.Finally,the effect of NW length on sensor performance is investigated and an inverse relation between sensor sensitivity and NW length is achieved.

  16. High Input Voltage Discharge Supply for High Power Hall Thrusters Using Silicon Carbide Devices

    Science.gov (United States)

    Pinero, Luis R.; Scheidegger, Robert J.; Aulsio, Michael V.; Birchenough, Arthur G.

    2014-01-01

    A power processing unit for a 15 kW Hall thruster is under development at NASA Glenn Research Center. The unit produces up to 400 VDC with two parallel 7.5 kW discharge modules that operate from a 300 VDC nominal input voltage. Silicon carbide MOSFETs and diodes were used in this design because they were the best choice to handle the high voltage stress while delivering high efficiency and low specific mass. Efficiencies in excess of 97 percent were demonstrated during integration testing with the NASA-300M 20 kW Hall thruster. Electromagnet, cathode keeper, and heater supplies were also developed and will be integrated with the discharge supply into a vacuum-rated brassboard power processing unit with full flight functionality. This design could be evolved into a flight unit for future missions that requires high power electric propulsion.

  17. Inverse-magnetostriction-induced switching current reduction of STT-MTJs and its application for low-voltage MRAM

    Science.gov (United States)

    Takamura, Yota; Shuto, Yusuke; Yamamoto, Shu'uichiro; Funakubo, Hiroshi; Kurosawa, Minoru Kuribayashi; Nakagawa, Shigeki; Sugahara, Satoshi

    2017-02-01

    A new spin-transfer torque (STT) magnetic tunnel junction (MTJ) using an inverse magnetostriction (IMS) material for the free layer is proposed for low-voltage MRAMs. The MTJ is surrounded by a piezoelectric gate structure so that a pressure for introducing the IMS effect can efficiently be applied to the free layer without any high-yield-strength support structure. During STT-induced magnetization switching, the energy barrier height for the switching can be lowered by the IMS effect, and thus a critical current density (JC) for the magnetization switching can dramatically be reduced. Energy performance of a low-voltage STT-MRAM cell using the proposed MTJ and a FinFET is also demonstrated.

  18. Performance enhancement of ITO/oxide/semiconductor MOS-structure silicon solar cells with voltage biasing.

    Science.gov (United States)

    Ho, Wen-Jeng; Huang, Min-Chun; Lee, Yi-Yu; Hou, Zhong-Fu; Liao, Changn-Jyun

    2014-01-01

    In this study, we demonstrate the photovoltaic performance enhancement of a p-n junction silicon solar cell using a transparent-antireflective ITO/oxide film deposited on the spacing of the front-side finger electrodes and with a DC voltage applied on the ITO-electrode. The depletion width of the p-n junction under the ITO-electrode was induced and extended while the absorbed volume and built-in electric field were also increased when the biasing voltage was increased. The photocurrent and conversion efficiency were increased because more photo-carriers are generated in a larger absorbed volume and because the carriers transported and collected more effectively due to higher biasing voltage effects. Compared to a reference solar cell (which was biased at 0 V), a conversion efficiency enhancement of 26.57% (from 12.42% to 15.72%) and short-circuit current density enhancement of 42.43% (from 29.51 to 42.03 mA/cm(2)) were obtained as the proposed MOS-structure solar cell biased at 2.5 V. In addition, the capacitance-volt (C-V) measurement was also used to examine the mechanism of photovoltaic performance enhancement due to the depletion width being enlarged by applying a DC voltage on an ITO-electrode.

  19. Silicon Carbide MOSFET-Based Switching Power Amplifier for Precision Magnet Control

    Science.gov (United States)

    Miller, Kenneth; Ziemba, Timothy; Prager, James; Picard, Julian

    2016-10-01

    Eagle Harbor Technologies, Inc. (EHT) is using the latest in solid-state switching technologies to advance the state-of-the-art in magnet control for fusion science. Silicon carbide (SiC) MOSFETs offer advantages over IGBTs including lower drive energy requirements, lower conduction and switching losses, and higher switching frequency capabilities. When comparing SiC and traditional silicon-based MOSFETs, SiC MOSFETs provide higher current carrying capability allowing for smaller package weights and sizes and lower operating temperature. To validate the design, EHT has developed a low-power switching power amplifier (SPA), which has been used for precision control of magnetic fields, including rapidly changing the fields in coils. This design has been incorporated in to a high power SPA, which has been bench tested. This high power SPA will be tested at the Helicity Injected Torus (HIT) at the University of Washington. Following successful testing, EHT will produce enough SiC MOSFET-based SPAs to replace all of the units at HIT, which allows for higher frequency operation and an overall increase in pulsed current levels.

  20. Design of a constant-voltage and constant-current controller with dual-loop and adaptive switching frequency control

    Science.gov (United States)

    Yingping, Chen; Zhiqian, Li

    2015-05-01

    A 5.0-V 2.0-A flyback power supply controller providing constant-voltage (CV) and constant-current (CC) output regulation without the use of an optical coupler is presented. Dual-close-loop control is proposed here due to its better regulation performance of tolerance over process and temperature compared with open loop control used in common. At the same time, the two modes, CC and CV, could switch to each other automatically and smoothly according to the output voltage level not sacrificing the regulation accuracy at the switching phase, which overcomes the drawback of the digital control scheme depending on a hysteresis comparator to change the mode. On-chip compensation using active capacitor multiplier technique is applied to stabilize the voltage loop, eliminate an additional package pin, and save on the die area. The system consumes as little as 100 mW at no-load condition without degrading the transient response performance by utilizing the adaptive switching frequency control mode. The proposed controller has been implemented in a commercial 0.35-μm 40-V BCD process, and the active chip area is 1.5 × 1.0 mm2. The total error of the output voltage due to line and load variations is less than ±1.7%.

  1. A 150-nA 13.4-ppm/℃ switched-capacitor CMOS sub-bandgap voltage reference*

    Institute of Scientific and Technical Information of China (English)

    Yan Wei; Li Wenhong; Liu Ran

    2011-01-01

    A nanopower switched-capacitor CMOS sub-bandgap voltage reference has been implemented using a Chartered 0.35-μm 3.3-V/5-V dual gate mixed-signal CMOS process The proposed circuit generates a precise sub-bandgap voltage of l V. The temperature coefficient of the output voltage is 13.4 ppm/℃ with the temperature varying from-20 to 80 ℃ The proposed circuit operates properly with the supply voltage down to 1.3 V, and consumes 150 nA at room temperature. The line regulation is 0.27%/V The power supply rejection ratio at 100 Hz and l MHz is -39 dB and 51 dB, respectively. The chip area is 0.2 mm2.

  2. Voltage- and current-activated metal–insulator transition in VO2-based electrical switches: a lifetime operation analysis

    Directory of Open Access Journals (Sweden)

    Aurelian Crunteanu, Julien Givernaud, Jonathan Leroy, David Mardivirin, Corinne Champeaux, Jean-Christophe Orlianges, Alain Catherinot and Pierre Blondy

    2010-01-01

    Full Text Available Vanadium dioxide is an intensively studied material that undergoes a temperature-induced metal–insulator phase transition accompanied by a large change in electrical resistivity. Electrical switches based on this material show promising properties in terms of speed and broadband operation. The exploration of the failure behavior and reliability of such devices is very important in view of their integration in practical electronic circuits. We performed systematic lifetime investigations of two-terminal switches based on the electrical activation of the metal–insulator transition in VO2 thin films. The devices were integrated in coplanar microwave waveguides (CPWs in series configuration. We detected the evolution of a 10 GHz microwave signal transmitted through the CPW, modulated by the activation of the VO2 switches in both voltage- and current-controlled modes. We demonstrated enhanced lifetime operation of current-controlled VO2-based switching (more than 260 million cycles without failure compared with the voltage-activated mode (breakdown at around 16 million activation cycles. The evolution of the electrical self-oscillations of a VO2-based switch induced in the current-operated mode is a subtle indicator of the material properties modification and can be used to monitor its behavior under various external stresses in sensor applications.

  3. Simultaneous Kerr and Faraday investigations of boundary magnetization and order parameter switching in voltage-controllable exchange bias films

    Science.gov (United States)

    Wang, Junlei; Echtenkamp, Will; Street, Mike; Binek, Christian

    2015-03-01

    Magnetoelectric oxides are of great interest for ultra-low power spintronics with memory and logic function. A key property for the realization of electrically switchable state variables is the voltage-controlled boundary magnetization in magnetoelectric antiferromagnets. It allows electric switching of an adjacent exchange coupled ferromagnetic layer in the absence of dissipative currents. Previous surface sensitive measurements of boundary magnetization in thin films of the archetypical magnetoelectric antiferromagnet chromia lacked explicit demonstration of the predicted rigid coupling between the bulk antiferromagnetic order parameter and the boundary magnetization. We designed a magneto-optical setup allowing simultaneous measurement of Kerr and Faraday rotation. Our experiments correlate electric field induced bulk magneto-optical effects (non-reciprocal rotation), including the response on switching of the antiferromagnetic order parameter, with the boundary magnetization. Our results suggest that switching of a ferromagnetic film strongly exchange coupled to a magnetoelectric antiferromagnetic ultra-thin film allows switching of the antiferromagnetic order parameter. We investigate the possibility that this switching phenomenon might induce a voltage pulse via a generalized variation of the inverse linear magnetoelectric effect. This project was supported by SRC through CNFD, an SRC-NRI Center, by C-SPIN, part of STARnet, and by the NSF through MRSEC.

  4. Inner surface flash-over of insulator of low-inductance high-voltage self-breakdown gas switch and its application.

    Science.gov (United States)

    Zhang, Hong-Bo; Liu, Jin-liang

    2014-04-01

    In this paper, the inner surface flash-over of high-voltage self-breakdown switch, which is used as a main switch of pulse modulator, is analyzed in theory by employing the method of distributed element equivalent circuit. Moreover, the field distortion of the switch is simulated by using software. The results of theoretical analysis and simulation by software show that the inner surface flash-over usually starts at the junction points among the stainless steel, insulator, and insulation gas in the switch. A switch with improved structure is designed and fabricated according to the theoretical analysis and simulation results. Several methods to avoid inner surface flash-over are used to improve the structure of switch. In experiment, the inductance of the switch is no more than 100 nH, the working voltage of the switch is about 600 kV, and the output voltage and current of the accelerator is about 500 kV and 50 kA, respectively. And the zero-to-peak rise time of output voltage at matched load is less than 30 ns due to the small inductance of switch. The original switch was broken-down after dozens of experiments, and the improved switch has been worked more than 200 times stably.

  5. The effect of diffusion induced lattice stress on the open-circuit voltage in silicon solar cells

    Science.gov (United States)

    Weizer, V. G.; Godlewski, M. P.

    1984-01-01

    It is demonstrated that diffusion induced stresses in low resistivity silicon solar cells can significantly reduce both the open-circuit voltage and collection efficiency. The degradation mechanism involves stress induced changes in both the minority carrier mobility and the diffusion length. Thermal recovery characteristics indicate that the stresses are relieved at higher temperatures by divacancy flow (silicon self diffusion). The level of residual stress in as-fabricated cells was found to be negligible in the cells tested.

  6. Limitations on the open-circuit voltage imposed by P/+/ and N/+/ regions in silicon solar cells

    Science.gov (United States)

    Shibib, M. A.; Fossum, J. G.

    1981-02-01

    It is shown theoretically and experimentally that the emitter recombination current, which limits the open-circuit voltage of silicon solar cells, can be more easily suppressed in P(+)N cells than in N(+)P cells. This result is due to fundamental effects that occur in heavily doped silicon: degeneracy of the majority charge carriers, Auger recombination, and energy-band-gap narrowing. Cell designs to suppress the emitter current are discussed, and experimental data supporting our theoretical analysis are presented.

  7. Hybrid silicon-plasmonics: efficient waveguide interfacing for low-loss integrated switching components

    Science.gov (United States)

    Tsilipakos, Odysseas; Pitilakis, Alexandros; Kriezis, Emmanouil E.

    2012-04-01

    We present a thorough numerical investigation of end-fire coupling between dielectric-loaded surface plasmon polariton (DLSPP) and compact rib/wire silicon-on-insulator (SOI) waveguides. Simulations are based on the three-dimensional vector finite element method. The interface geometrical parameters leading to optimum performance, i.e., maximum coupling efficiency or, equivalently, minimum insertion loss (IL), are identified. We show that coupling efficiencies as high as 85 % are possible. In addition, we quantify the fabrication tolerances about the optimum parameter values. In the same context, we assess the effect of a metallic stripe gap and that of a horizontal offset between waveguides on insertion loss. Finally, we demonstrate that by benefiting form the low-loss coupling between the two waveguides, hybrid silicon-plasmonic 2 x 2 thermo-optic switching elements can outperform their all-plasmonic counterparts in terms of IL. Specifically, we examine two hybrid SOI-DLSPP switching elements, namely, a Mach-Zehnder Interferometer (MZI) and a Multi-Mode-Interference (MMI) switch. In particular, in the MZI case the IL improvement compared to the all-plasmonic counterpart is 4.5 dB. Moreover, the proposed hybrid components maintain the high extinction ratio, small footprint, and efficient tuning traits of plasmonic technology.

  8. Stable single-mode operation of injection-seeded Q-switched Nd:YAG laser by sine voltage modulation

    Institute of Scientific and Technical Information of China (English)

    Yongfei Gao; Junxuan Zhang; Huaguo Zang; Xiaolei Zhu; Yingjie Yu; Weibiao Chen

    2016-01-01

    Based on the modified ramp and fire technique,a novel injection seeding approach with real-time resonance tracking is successfully demonstrated in a single-frequency Nd:YAG pulsed laser.Appling a high-frequency sinusoidal modulation voltage to one piezo actuator and an adjustable DC voltage to another piezo actuator for active feedback,single-mode laser output with high-frequency stability is obtained,and the effect of the piezo hysteresis on the frequency stability can be eliminated for a laser diode pumped Q-switched Nd:YAG laser at a repetition rate of 400 Hz.

  9. Investigations of surface characterization of silicone rubber due to tracking phenomena under a.c. and d.c. voltages

    Indian Academy of Sciences (India)

    Uma Maheswar Rao; S S M S Abdul Majeed; C Venkataseshaiah; R Sarathi

    2002-11-01

    In the present work, tracking phenomena has been studied with silicone rubber material under the a.c. and d.c. voltages following IEC-587 standards. The surface condition of the tracked zone was analysed using wide angle X-ray diffraction (WAXD) and thermogravimetric differential thermal analysis (TG–DTA) studies. The tracking time was different for a.c. and d.c. voltages.

  10. Uncertainty estimation of non-ideal analog switches using programmable Josephson voltage standards for mutual inductance measurement in the joule balance

    Science.gov (United States)

    Wang, Gang; Zhang, Zhonghua; Li, Zhengkun; Xu, Jinxin; You, Qiang

    2016-02-01

    Measurement of the mutual inductance is one of the key techniques in the joule balance to determine the Planck constant h, where a standard-square-wave compensation method was proposed to accurately measure the dc value of the mutual inductance. With this method, analog switches are used to compose an analog-switch signal generator to synthesize the excitation and compensation voltages. However, the accuracy of the compensation voltage is influenced by the non-ideal behaviors of analog-switches. In this paper, the effect from these non-ideal switches is analyzed in detail and evaluated with the equivalent circuits. A programmable Josephson voltage standard (PJVS) is used to generate a reference compensation voltage to measure the time integration of the voltage waveform generated by the analog-switch signal generator. Moreover, the effect is also evaluated experimentally by comparing the difference between the mutual inductance measured with the analog-switch signal generator and the value determined by the PJVS-analog-switch generator alternately in the same mutual inductance measurement system. The result shows that the impact of analog switches is 1.97  ×  10-7 with an uncertainty of 1.83  ×  10-7 (k  =  1) and confirms that the analog switch method can be used regularly instead of the PJVS in the mutual inductance measurement for the joule balance experiment.

  11. Influence of different illumination profiles on the on-state resistances of silicon carbide photoconductive semiconductor switches

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Langning, E-mail: wanglangning@126.com; Xun, Tao; Yang, Hanwu; Liu, Jinliang; Zhang, Yu [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2014-04-15

    Characteristics of a silicon-carbide (SiC) photoconductive switch under different illumination profiles are presented. We triggered a V-doped semi-insulated 6H-SiC switch with lateral geometry using a laser beam of 532-nm wavelength. Photoconductivity tests for different spot profiles and locations show that such switches achieve a minimum on-state resistance when the switching gap is illuminated. The differences between on-state resistances are small for various partial illuminations of the switching gap. Semiconductor modeling is used to simulate the electric field and current profiles for different partial illuminations. The simulation results show poor on-state switch performance when partially illuminated. Based on these results, a more revealing circuit model for the switch matches well with experimental results for partial illuminations.

  12. Influence of different illumination profiles on the on-state resistances of silicon carbide photoconductive semiconductor switches.

    Science.gov (United States)

    Wang, Langning; Xun, Tao; Yang, Hanwu; Liu, Jinliang; Zhang, Yu

    2014-04-01

    Characteristics of a silicon-carbide (SiC) photoconductive switch under different illumination profiles are presented. We triggered a V-doped semi-insulated 6H-SiC switch with lateral geometry using a laser beam of 532-nm wavelength. Photoconductivity tests for different spot profiles and locations show that such switches achieve a minimum on-state resistance when the switching gap is illuminated. The differences between on-state resistances are small for various partial illuminations of the switching gap. Semiconductor modeling is used to simulate the electric field and current profiles for different partial illuminations. The simulation results show poor on-state switch performance when partially illuminated. Based on these results, a more revealing circuit model for the switch matches well with experimental results for partial illuminations.

  13. Effective description of tunneling in a time-dependent potential with applications to voltage switching in Josephson junctions

    DEFF Research Database (Denmark)

    Andersen, Christian Kraglund; Mølmer, Klaus

    2013-01-01

    We propose to use a time-dependent imaginary potential to describe quantum mechanical tunneling through time-varying potential barriers. We use Gamow solutions for stationary tunneling problems to justify our choice of potential, and we apply our method to describe tunneling of a mesoscopic quantum...... variable: the phase change across a Josephson junction. The Josephson junction phase variable behaves as the position coordinate of a particle moving in a tilted washboard potential, and our general solution to the motion in such a potential with a time-dependent tilt reproduces a number of features...... associated with voltage switching in Josephson junctions. Apart from applications as artificial atoms in quantum information studies, the Josephson junction may serve as an electric field sensitive detector, and our studies provide a detailed understanding of how the voltage switching dynamics couples...

  14. Design of a Low-Voltage High-Speed Switched-Capacitor Filters Using Improved Auto Zeroed Integrator

    Science.gov (United States)

    Rashtian, M.; Hashemipour, O.; Navi, K.

    The low-voltage high-speed auto zeroed integrator characteristics is improved by applying current steering mechanism in the opamp structure of the integrators and utilizing the non-linear properties of switches. The proposed design results in considerable reduction of power dissipation. Based on this improvement a band-pass filter with centre frequency of 1 MHz and clock frequency of 6 MHz is designed. Furthermore a new circuit for implementation of an auto-zero low-pass filter is presented. Based on this configuration a fourth order low-pass switched capacitor filter with cut off frequency of 600 KHz and clock frequency of 6 MHz is presented. The proposed circuits are simulated using HSPICE and 0.25 μm CMOS technology at 1.5 V supply voltage.

  15. Effective description of tunneling in a time-dependent potential with applications to voltage switching in Josephson junctions

    DEFF Research Database (Denmark)

    Andersen, Christian Kraglund; Mølmer, Klaus

    2013-01-01

    variable: the phase change across a Josephson junction. The Josephson junction phase variable behaves as the position coordinate of a particle moving in a tilted washboard potential, and our general solution to the motion in such a potential with a time-dependent tilt reproduces a number of features......We propose to use a time-dependent imaginary potential to describe quantum mechanical tunneling through time-varying potential barriers. We use Gamow solutions for stationary tunneling problems to justify our choice of potential, and we apply our method to describe tunneling of a mesoscopic quantum...... associated with voltage switching in Josephson junctions. Apart from applications as artificial atoms in quantum information studies, the Josephson junction may serve as an electric field sensitive detector, and our studies provide a detailed understanding of how the voltage switching dynamics couples...

  16. Measurement ot the switching over-voltages at the disconnection of the high voltage shunt reactors in the Romanian power system

    Energy Technology Data Exchange (ETDEWEB)

    Stroica, Paul Constantin; Merfu, Ion; Stroica, Mihail; Merfu, Marius; Cojocaru, Florian; Stefan, Dinu; Cojocaru, Mihai

    2010-09-15

    The paper presents the measurements of the switching over-voltages made in the Romanian Power System, at the 400/220/110 kV Urechesti substation at the disconnection of a 400 kV, 100 MVAr shunt reactor type DFAL, Siemens, Germany, in 3 consecutive versions. The first one is for shunt reactor controlled by live-tank oil circuit breaker, the second one is for shunt reactor controlled by SF6 circuit breaker, and the third one is for shunt reactor controlled by SF6 circuit breaker and synchronize device.

  17. Bendable high-frequency microwave switches formed with single-crystal silicon nanomembranes on plastic substrates

    Science.gov (United States)

    Yuan, Hao-Chih; Qin, Guoxuan; Celler, George K.; Ma, Zhenqiang

    2009-07-01

    This letter presents realization of bendable rf switches operating at microwave frequencies formed with single-crystal Si nanomembranes (SiNMs) on a plastic substrate. Selectively doped 200-nm-thick SiNM is lifted off from silicon-on-insulator and transferred to a polymer substrate to form lateral P-intrinsic-N (PIN) diodes with minimized parasitic resistances. A single-pole single-throw switch, consisting of two PIN diodes connected in a shunt-series configuration, demonstrated very low insertion loss and high isolation from dc up to 20 GHz. The level of performance indicates a promise of properly processed single-crystal semiconductor nanomembranes for high-frequency applications in a number of consumer and military systems.

  18. Strictly non-blocking 4×4 silicon electro-optic switch matrix

    Science.gov (United States)

    Zhou, Pei-Ji; Xing, Jie-Jiang; Li, Xian-Yao; Li, Zhi-Yong; Yu, Jin-Zhong; Yu, Yu-De

    2015-12-01

    The first path-independent insertion-loss (PILOSS) strictly non-blocking 4×4 silicon electro-optic switch matrix is reported. The footprint of this switch matrix is only 4.6 mm×1.0 mm. Using single-arm modulation, the crosstalk measured in this test is -13 dB˜ -27 dB. And a maximum crosstalk deterioration of 6dB caused by two-path interference is also found. Project supported by the National Basic Research Program of China (Grant No. 2011CB301701), the National High Technology Research and Development Program of China (Grant Nos. 2013AA014402, 2012AA012202, and 2015AA016904), and the National Natural Science Foundation of China (Grant Nos. 61275065 and 61107048).

  19. Total internal reflection optical switch using the reverse breakdown of a pn junction in silicon.

    Science.gov (United States)

    Kim, Jong-Hun; Park, Hyo-Hoon

    2015-11-01

    We demonstrate a new type of silicon total-internal-reflection optical switch with a simple pn junction functioning both as a reflector and a heater. The reflector is placed between asymmetrically y-branched multimode waveguides with an inclination angle corresponding to half of the branch angle. When the reflector is at rest, incident light is reflected in accordance to the refractive index difference due to the plasma dispersion effect of the pre-doped carriers. Switching to the transmission state is attained under a reverse breakdown of the pn junction by the thermo-optic effect which smears the refractive index difference. From this switching scheme, we confirmed the switching operation with a shallow total-internal-reflection region of 1 μm width. At a 6° branch angle, an extinction ratio of 12 dB and an insertion loss of -4.2  dB are achieved along with a thermal heating power of 151.5 mW.

  20. Spectroscopic measurements with a silicon drift detector having a continuous implanted drift cathode-voltage divider

    CERN Document Server

    Bonvicini, V; D'Acunto, L; Franck, D; Gregorio, A; Pihet, P; Rashevsky, A; Vacchi, A; Vinogradov, L I; Zampa, N

    2000-01-01

    A silicon drift detector (SDD) prototype where the drift electrode also plays the role of a high-voltage divider has been realised and characterised for spectroscopic applications at near-room temperatures. Among the advantages of this design, is the absence of metal on the sensitive surface which makes this detector interesting for soft X-rays. The detector prototype has a large sensitive area (2x130 mm sup 2) and the charge is collected by two anodes (butterfly-like detector). The energy resolution of a such a detector has been investigated at near-room temperatures using a commercial, hybrid, low-noise charge-sensitive preamplifier. The results obtained for the X-ray lines from sup 5 sup 5 Fe and sup 2 sup 4 sup 1 Am are presented.

  1. Low-Power Circuit Techniques for Low-Voltage Pipelined ADCs Based on Switched-Opamp Architecture

    Science.gov (United States)

    Ou, Hsin-Hung; Chang, Soon-Jyh; Liu, Bin-Da

    This paper proposes useful circuit structures for achieving a low-voltage/low-power pipelined ADC based on switched-opamp architecture. First, a novel unity-feedback-factor sample-and-hold which manipulates the features of switched-opamp technique is presented. Second, opamp-sharing is merged into switched-opamp structure with a proposed dual-output opamp configuration. A 0.8-V, 9-bit, 10-Msample/s pipelined ADC is designed to verify the proposed circuit. Simulation results using a 0.18-μm CMOS 1P6M process demonstrate the figure-of-merit of this pipelined ADC is only 0.71pJ/step.

  2. Surface plasmon polaritons on soft-boundary graphene nanoribbons and their application as voltage controlled plasmonic switches and frequency demultiplexers

    CERN Document Server

    Forati, Ebrahim

    2013-01-01

    A graphene sheet gated with a ridged ground plane, creating a soft-boundary (SB) graphene nanoribbon, is considered. By adjusting the ridge parameters and bias voltage a channel can be created on the graphene which can guide TM surface plasmon polaritons (SPP). Two types of modes are found; fundemental and higher-order modes with no apparent cutoff frequency and with energy distributed over the created channel, and edge modes with energy concen-trated at the soft-boundary edge. Dispersion curves, electric near-field patterns, and current distributions of these modes are determined. Since the location where energy is concentrated in the edge modes can be easily controlled electronically by the bias voltage and frequency, the edge-mode phenomena is used to propose a novel voltage controlled plasmonic switch and a plasmonic frequency demultiplexer.

  3. Characterization of Multicrystalline Silicon Modules with System Bias Voltage Applied in Damp Heat

    Energy Technology Data Exchange (ETDEWEB)

    Hacke, P.; Kempe, M.; Terwilliger, K.; Glick, S.; Call, N.; Johnston, S.; Kurtz, S.

    2011-07-01

    As it is considered economically favorable to serially connect modules to build arrays with high system voltage, it is necessary to explore potential long-term degradation mechanisms the modules may incur under such electrical potential. We performed accelerated lifetime testing of multicrystalline silicon PV modules in 85 degrees C/ 85% relative humidity and 45 degrees C/ 30% relative humidity while placing the active layer in either positive or negative 600 V bias with respect to the grounded module frame. Negative bias applied to the active layer in some cases leads to more rapid and catastrophic module power degradation. This is associated with significant shunting of individual cells as indicated by electroluminescence, thermal imaging, and I-V curves. Mass spectroscopy results support ion migration as one of the causes. Electrolytic corrosion is seen occurring with the silicon nitride antireflective coating and silver gridlines, and there is ionic transport of metallization at the encapsulant interface observed with damp heat and applied bias. Leakage current and module degradation is found to be highly dependent upon the module construction, with factors such as encapsulant and front glass resistivity affecting performance. Measured leakage currents range from about the same seen in published reports of modules deployed in Florida (USA) and is accelerated to up to 100 times higher in the environmental chamber testing.

  4. Design, fabrication, testing and packaging of a silicon micromachined radio frequency microelectromechanical series (RF MEMS) switch

    Indian Academy of Sciences (India)

    M S Giridhar; Ashwini Jambhalikar; Jiju John; R Islam; Ananda Behera; C L Nagendra; George Thachil; M P Srikanth; Shailesh Somani; B H M Darukesha; Srinivasarao Bollu

    2013-04-01

    RF characterization and packaging of a single pole single throw (SPST) direct contact microelectromechanical (MEMS) series radio frequency (RF) switch is reported. Precise thickness of the silicon MEMS structure is achieved using a specially developed silicon Deep Reactive Ion Etching (DRIE) thinning process. A stress free release process is employed which ensures a high yield of released microstructures. The design of the device is based on stiffness equations derived from first principles. Displacement of the actuator under applied field is measured to confirm electrostatic pull in, which occurs in the 30–50 V range. The variation of contact resistance with time has been measured and is found to have a power law decay, in agreement with theoretical models. At the bare die level the insertion loss, return loss and the isolation of the switch were measured to be −0.43 dB, −25 dB and −21 dB, respectively at 10 GHz. The devices were packaged in commercially available RF packages and mounted in alumina boards for post package characterization. Due to the presence of bond wires in the signal path of the packaged devices, the RF performance was found to degrade at high frequencies. However, losses were measured to be at acceptable levels up to 2 GHz. Factors contributing to insertion loss at the die and package device levels are discussed in detail with possible solutions.

  5. 一种高可靠性开关稳压电源的研制%The Development of the High Reliable Switching Voltage Stabilizer

    Institute of Scientific and Technical Information of China (English)

    王建; 赵福成; 单世东

    2001-01-01

    介绍一种变电站用的开关稳压电源,分析其主电路及控 制电路的原理,及其高可靠性。%The switching voltage stabilizer for the transformer substation is presented. Th e principle of the main circuit and control circuit is analysed. This switching voltage stabilizer is high reliable.

  6. High response piezoelectric and piezoresistive materials for fast, low voltage switching: simulation and theory of transduction physics at the nanometer-scale.

    Science.gov (United States)

    Newns, Dennis M; Elmegreen, Bruce G; Liu, Xiao-Hu; Martyna, Glenn J

    2012-07-17

    Field effect transistors are reaching the limits imposed by the scaling of materials and the electrostatic gating physics underlying the device. In this Communication, a new type of switch based on different physics, which combines known piezoelectric and piezoresistive materials, is described and is shown by theory and simulation to achieve gigahertz digital switching at low voltage (0.1 V).

  7. A High-Voltage class-D power amplifier with switching frequency regulation for improved high-efficiency output power range

    NARCIS (Netherlands)

    Ma, Haifeng; Zee, van der Ronan; Nauta, Bram

    2015-01-01

    This paper describes the power dissipation analysis and the design of an efficiency-improved high-voltage class-D power amplifier. The amplifier adaptively regulates its switching frequency for optimal power efficiency across the full output power range. This is based on detecting the switching outp

  8. A pulsed-power generator merging inductive voltage and current adders and its switch trigger application example.

    Science.gov (United States)

    Li, Lee; Yafeng, Ge; Heqin, Zhong; Bin, Yu; Longjun, Xie

    2013-07-01

    A pulsed-power generator using inductive adder technology is proposed for the case of a discharge gap. The merit of this generator is to merge the pulsed-voltage and pulsed-current adders via the dual secondary windings with special circuit. For the nonlinear impedance in any discharge gap, the standalone voltage-pulse and current-pulse can be outputted successively by this generator. The proposed generator is especially useful for the common resolution of implementing pulse discharge at less cost. As an application example, a compact trigger prototype was developed to compatibly use in the gas-insulated and vacuum switches. Experiments achieved good results that the triggered switches showed stable performance and long life. If the basic circuit of this proposed generator is regarded as a pulsed-generating unit, a certain number of such units connected in parallel can be expected to form a general device with generating greater breakdown-voltage and sustained-current pulses for discharge gaps.

  9. A silicon doped hafnium oxide ferroelectric p–n–p–n SOI tunneling field–effect transistor with steep subthreshold slope and high switching state current ratio

    Directory of Open Access Journals (Sweden)

    Saeid Marjani

    2016-09-01

    Full Text Available In this paper, a silicon–on–insulator (SOI p–n–p–n tunneling field–effect transistor (TFET with a silicon doped hafnium oxide (Si:HfO2 ferroelectric gate stack is proposed and investigated via 2D device simulation with a calibrated nonlocal band–to–band tunneling model. Utilization of Si:HfO2 instead of conventional perovskite ferroelectrics such as lead zirconium titanate (PbZrTiO3 and strontium bismuth tantalate (SrBi2Ta2O9 provides compatibility to the CMOS process as well as improved device scalability. By using Si:HfO2 ferroelectric gate stack, the applied gate voltage is effectively amplified that causes increased electric field at the tunneling junction and reduced tunneling barrier width. Compared with the conventional p–n–p–n SOI TFET, the on–state current and switching state current ratio are appreciably increased; and the average subthreshold slope (SS is effectively reduced. The simulation results of Si:HfO2 ferroelectric p–n–p–n SOI TFET show significant improvement in transconductance (∼9.8X enhancement at high overdrive voltage and average subthreshold slope (∼35% enhancement over nine decades of drain current at room temperature, indicating that this device is a promising candidate to strengthen the performance of p–n–p–n and conventional TFET for a switching performance.

  10. High holding voltage segmentation stacking silicon-controlled-rectifier structure with field implant as body ties blocking layer

    Science.gov (United States)

    Yen, Shiang-Shiou; Cheng, Chun-Hu; Lan, Yu-Pin; Chiu, Yu-Chien; Fan, Chia-Chi; Hsu, Hsiao-Hsuan; Chang, Shao-Chin; Jiang, Zhe-Wei; Hung, Li-Yue; Tsai, Chi-Chung; Chang, Chun-Yen

    2016-04-01

    High electrostatic discharge (ESD) protection robustness and good transient-induced latchup immunity are two important issues for high voltage integrate circuit application. In this study, we report a high-voltage-n-type-field (HVNF) implantation to act as the body ties blocking layer in segmented topology silicon-controlled-rectifier (SCR) structure in 0.11 µm 32 V high voltage process. This body ties blocking layer eliminate the elevated triggered voltage in segmented technique. Using a large resistance as shunt resistor in resistor assisted triggered SCRs stacking structure, the double snapback phenomenon is eliminate. The series SCR could be decoupled a sufficient voltage drop to turned-on when a very low current flow through the shunt resistor. The holding voltage and the failure current of 22 V and 3.4 A are achieved in the best condition of segmented topology SCR stacking structure, respectively. It improves the latchup immunity at high voltage ICs application. On the other hand, the triggered voltage almost keep the same value which is identical to SCR single cell without using segmented topology.

  11. Design and Performance Evaluation of Optical Ethernet Switching Architecture with Liquid Crystal on Silicon-Based Beam-Steering Technology

    Science.gov (United States)

    Cheng, Yuh-Jiuh; Chou, H.-H.; Shiau, Yhi; Cheng, Shu-Ying

    2016-07-01

    A non-blocking optical Ethernet switching architecture with liquid crystal on a silicon-based beam-steering switch and optical output buffer strategies are proposed. For preserving service packet sequencing and fairness of routing sequence, priority and round-robin algorithms are adopted at the optical output buffer in this research. Four methods were used to implement tunable fiber delay modules for the optical output buffers to handle Ethernet packets with variable bit-rates. The results reported are based on the simulations performed to evaluate the proposed switching architecture with traffic analysis under a traffic model captured from a real-core network.

  12. The correlation of open-circuit voltage with bandgap in amorphous silicon-based pin solar cells

    Science.gov (United States)

    Crandall, R. S.; Schiff, E. A.

    1996-01-01

    We briefly review the correlation of open-circuit voltages VOC with the bandgap of the intrinsic layer in amorphous silicon based pin solar cells. We discuss two mechanisms which limit VOC: intrinsic layer recombination, and the built-in potential VBI. In particular we discuss Li's proposal that the open-circuit voltages in higher bandgap cells (EG>1.9 eV) are VBI-limited. Based on computer simulations of pin solar cells we propose that VBI limitation occurs when the recombination limit to VOC exceeds the cell's field-reversal voltage VR. For a-Si:H based cells this field-reversal voltage occurs at about VBI-0.3 V. This proposal would account for the observation that VBI limitation occurs for VOC significantly smaller than VBI.

  13. Effect of voltage sags on digitally controlled line connected switched-mode power supplies

    DEFF Research Database (Denmark)

    Török, Lajos; Munk-Nielsen, Stig

    2012-01-01

    Different voltage disorders like voltage fluctuations, sags, frequency variations may occur in the power supply networks due to different fault conditions. These deviations from normal operation affects in different ways the line connected devices. Standards were developed to protect and ensure i...

  14. Five-Level Converter with Low Switching Frequency Applied as DC Voltage Supply

    DEFF Research Database (Denmark)

    Rasmussen, Tonny Wederberg

    1999-01-01

    This paper describes the use of a multi-level converter as a DC supply. Equations for the converter will be deduced in the nondissipative case. The equations provide solutions to DC voltage and the angle of converter voltage. In addition the spectrum for the harmonics after the elimination...

  15. Ultra Low Energy Switching of Ferromagnet with Perpendicular Anisotropy on Topological Insulator by Voltage Controlled Magnetic Anisotropy

    Science.gov (United States)

    Ghosh, Bahniman; Pramanik, Tanmoy; Dey, Rik; Roy, Urmimala; Register, Leonard; Banerjee, Sanjay

    2015-03-01

    We propose and demonstrate, through simulation, an ultra low energy memory device on a topological insulator thin film. The device consists of a thin layer of Fe deposited on the surface of a topological insulator, Bi2Se3. The top surface of Fe is covered with MgO so that the ferromagnetic layer has perpendicular anisotropy. Current is passed on the surface of the topological insulator which switches the magnetization of the Fe ferromagnet through strong exchange interaction, between electrons contributing to the surface current on the Bi2Se3 and the d electrons in the ferromagnet, and spin transfer torque due to shunting of current through the ferromagnet. Voltage controlled magnetic anisotropy enables ultra low energy switching. Our micromagnetic simulations, predict switching time of the order of 2.4 ns and switching energy of the order of 0.16 fJ for a ferromagnetic bit with thermal stability of 90 kBT. The proposed structure combines the advantages of both large spin torque from topological insulators and those of perpendicular anisotropy materials. This work is supported by NRI SWAN and NSF NASCENT Center.

  16. Mechanism of Fast Current Interruption in p -π -n Diodes for Nanosecond Opening Switches in High-Voltage-Pulse Applications

    Science.gov (United States)

    Sharabani, Y.; Rosenwaks, Y.; Eger, D.

    2015-07-01

    Step-recovery diodes operating in the snappy recovery regime are used as opening switches for generating narrow pulses with high-voltage amplitude. Physical modeling of the switching process is complex due to the large number of parameters involved, including diode structure, the extreme physical conditions, and the effect of external driving conditions. In this work, we address the problem by using a physical device simulator for solving the coupled device and electrical driving circuit equations. This method allows deciphering of the physical processes to take place in the diode during the fast current interruption phase. Herein we analyze the complete hard (snappy) reverse recovery process in short-base devices and determine the fast-transition-phase mechanism. It was found that the fast current interruption phase is constructed of two processes; the main parameters governing the switching time duration and the prepulse magnitude are the diode's reverse current density and its base-doping concentration. We describe the dependence of the switching performance in these parameters.

  17. Voltage-stabilised elastomers with increased relative permittivity and high electrical breakdown strength by means of phase separating binary copolymer blends of silicone elastomers

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Yu, Liyun; Skov, Anne Ladegaard

    2017-01-01

    Increased electrical breakdown strength and increased dielectric permittivity of silicone-based dielectric elastomers are achieved by means of the addition of so-called voltage-stabilisers prepared from PDMS–PPMS copolymers as well as PDMS–PEG copolymers in order to compensate for the negative...... effect of softness on electrical stability of silicone elastomers. The voltage-stabilised elastomer, incorporating a high-permittivity PDMS–PEG copolymer, possesses increased relative permittivity, high electrical breakdown strength, excellent network integrity and low dielectric loss and paves the way...... towards specialised silicone elastomers for dielectric elastomer transducer products with inherent softness and electrical stability, and thus increased actuation at a given voltage....

  18. Self-assembled nanodielectrics and silicon nanomembranes for low voltage, flexible transistors, and logic gates on plastic substrates

    Science.gov (United States)

    Kim, Hoon-Sik; Won, Sang Min; Ha, Young-Geun; Ahn, Jong-Hyun; Facchetti, Antonio; Marks, Tobin J.; Rogers, John A.

    2009-11-01

    This letter reports the fabrication and electrical characterization of mechanically flexible and low operating voltage transistors and logic gates (NOT, NAND, and NOR gates) using printed silicon nanomembranes and self-assembled nanodielectrics on thin plastic substrates. The transistors exhibit effective linear mobilities of ˜680 cm2/V s, on/off ratios >107, gate leakage current densities <2.8×10-7 A/cm2, and subthreshold slopes ˜120 mV/decade. The inverters show voltage gains as high as 4.8. Simple digital logic gates (NAND and NOR gates) demonstrate the possible application of this materials combination in digital integrated circuits.

  19. The impact of etched trenches geometry and dielectric material on the electrical behaviour of silicon-on-insulator self-switching diodes

    Energy Technology Data Exchange (ETDEWEB)

    Farhi, G; Charlebois, S A [Departement de genie electrique et genie informatique, et Institut interdisciplinaire d' innovation technologique (3IT), Universite de Sherbrooke, 2500, Boulevard de l' Universite, J1K 2R1, Sherbrooke, QC (Canada); Morris, D [Departement de physique et Institut interdisciplinaire d' innovation technologique (3IT), Universite de Sherbrooke, 2500, Boulevard de l' Universite, J1K 2R1, Sherbrooke, QC (Canada); Raskin, J-P, E-mail: ghania.farhi@usherbrooke.ca [Institute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTEAM), Universite catholique de Louvain, Place du Levant, 3, B-1348 Louvain-la-Neuve (Belgium)

    2011-10-28

    Hole electrical transport in a p-doped nanochannel defined between two L-shape etched trenches made on a silicon-on-insulator substrate is investigated using a TCAD-Medici simulator. We study the impact of the etched trenches' geometry and dielectric filling materials on the current-voltage characteristics of the device. Carrier accumulation on frontiers defined by the trenches causes a modulation of the hole density inside the conduction channel as the bias voltage varies and this gives rise to a diode-like characteristic. For a 1.2 {mu}m-long channel, plots of the electric field distribution show that a nonlinear transport regime is reached at a moderate reverse and forward bias of {+-} 2 V. Plots of the carrier velocity along the conduction channel show that holes remain hot for a few hundreds of nm outside the nanometre-wide channel, at a bias of {+-} 10 V. Filling the etched trenches with a high-{kappa} dielectric material gives rise to a lower threshold voltage, V{sub th}. A similar decrease of V{sub th} is also achieved by reducing the longitudinal and/or the transverse trench width. Our simulation results provide useful design guidelines for future integrated self-switching-diode-based circuits.

  20. Silicon-on-insulator 1×2 Y-junction Optical Switch Based on Waveguide-vanishing Effect①②

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    The silicon-on-insulator(SOI)1×2Y-junction optical waveguide switch has been proposed and fabricated,which is based on the large cross-section single-mode rib waveguide condition,the waveguide-vanishing effect and the free-carrier plasma dispersion effect.In the switch,the SOI technique utilizer silicon and silicon dioxide thermal bonding and back-polishing.The insertion loss and extinction ratio of the device are measured to be less than 4.78dB and 20.8dB respectively at a wavelength of 1.3μm and an injection current of 45mA.Response time is about 160ns.

  1. High-speed and compact silicon modulator based on a racetrack resonator with a 1 V drive voltage.

    Science.gov (United States)

    Dong, Po; Liao, Shirong; Liang, Hong; Qian, Wei; Wang, Xin; Shafiiha, Roshanak; Feng, Dazeng; Li, Guoliang; Zheng, Xuezhe; Krishnamoorthy, Ashok V; Asghari, Mehdi

    2010-10-01

    Fast, compact, and power-efficient silicon microcavity electro-optic modulators are expected to be critical components for chip-level optical interconnects. It is highly desirable that these modulators can be driven by voltage swings of 1 V or less to reduce power dissipation and make them compatible with voltage supply levels associated with current and future complementary metal-oxide-semiconductor technology nodes. Here, we present a silicon racetrack resonator modulator that achieves over 8 dB modulation depth at 12.5 Gbps with a 1 V swing. In addition, the use of a racetrack resonator geometry relaxes the tight lithography resolution requirements typically associated with microring resonators and enhances the ability to use common lithographic optical techniques for their fabrication.

  2. Study program to improve the open-circuit voltage of low resistivity single crystal silicon solar cells

    Science.gov (United States)

    Minnucci, J. A.; Matthei, K. W.

    1980-01-01

    The results of a 14 month program to improve the open circuit voltage of low resistivity silicon solar cells are described. The approach was based on ion implantation in 0.1- to 10.0-ohm-cm float-zone silicon. As a result of the contract effort, open circuit voltages as high as 645 mV (AMO 25 C) were attained by high dose phosphorus implantation followed by furnace annealing and simultaneous SiO2 growth. One key element was to investigate the effects of bandgap narrowing caused by high doping concentrations in the junction layer. Considerable effort was applied to optimization of implant parameters, selection of furnace annealing techniques, and utilization of pulsed electron beam annealing to minimize thermal process-induced defects in the completed solar cells.

  3. All-optical switching via four-wave mixing Bragg scattering in a silicon platform

    CERN Document Server

    Zhao, Yun; Mathews, Jay; Agha, Imad

    2016-01-01

    We employ the process of non-degenerate four-wave mixing Bragg scattering (FWM-BS) to demonstrate all-optical control in a silicon platform. In our configuration, a strong, non-information-carrying pump is mixed with a weak control pump and an input signal in a silicon-on-insulator waveguide. Through the optical nonlinearity of this highly-confining waveguide, the weak pump controls the wavelength conversion process from the signal to an idler, leading to a controlled depletion of the signal. The strong pump, on the other hand, plays the role of a constant bias. In this work, we show experimentally that it is possible to implement this low-power switching technique as a first step towards universal optical logic gates, and test the performance with random binary data. Even at very low powers, where the signal and control pump levels are almost equal, the eye-diagrams remain open, indicating a successful operation of the logic gates.

  4. All-optical switching via four-wave mixing Bragg scattering in a silicon platform

    Directory of Open Access Journals (Sweden)

    Yun Zhao

    2017-02-01

    Full Text Available We employ the process of non-degenerate four-wave mixing Bragg scattering to demonstrate all-optical control in a silicon platform. In our configuration, a strong, non-information-carrying pump is mixed with a weak control pump and an input signal in a silicon-on-insulator waveguide. Through the optical nonlinearity of this highly confining waveguide, the weak pump controls the wavelength conversion process from the signal to an idler, leading to a controlled depletion of the signal. The strong pump, on the other hand, plays the role of a constant bias. In this work, we show experimentally that it is possible to implement this low-power switching technique as a first step towards universal optical logic gates, and test the performance with random binary data. Even at very low powers, where the signal and control pump levels are almost equal, the eye-diagrams remain open, indicating a successful operation of the logic gates.

  5. Design and development of a high-voltage coaxial-hydrogen switch

    Science.gov (United States)

    Burger, Jeffrey W.; Baum, Carl E.; Prather, William D.; Torres, Roger J.; Abdalla, Michael D.; Skipper, Mike C.; Cockreham, B. C.; McLemore, Donald

    2002-06-01

    The high power microwave program at the Air Force Research Lab (AFRL) includes high power source development in narrow band and wideband technologies. The H2 source is an existing wideband source that was developed at the AFRL. A recent AFRL requirement for a wideband impulse generator to use in materials tests has provided the need to update the H2 source for the current test requirements. The H2 source is composed of a dual resonant transformer that charges a short length of coaxial transmission line. The transmission line is then discharged into an output coaxial transmission line with a self-break Hydrogen switch. The dual resonant transformer is driven by a low inductance primary capacitor bank operating through a sel-break gas switch. The upgrade of the coaxial Hydrogen output switch is the focus of this paper. The Hydrogen output switch was developed through extensive electrical and mechanical simulations. The switch insulator is made of Ultem 2300 and is designed to operate with a mechanical factor of safety equal to 4.0 at 1,000 psi. The design criteria, design data and operational data will be presented.

  6. Prognostic health monitoring in switch-mode power supplies with voltage regulation

    Science.gov (United States)

    Hofmeister, James P (Inventor); Judkins, Justin B (Inventor)

    2009-01-01

    The system includes a current injection device in electrical communication with the switch mode power supply. The current injection device is positioned to alter the initial, non-zero load current when activated. A prognostic control is in communication with the current injection device, controlling activation of the current injection device. A frequency detector is positioned to receive an output signal from the switch mode power supply and is able to count cycles in a sinusoidal wave within the output signal. An output device is in communication with the frequency detector. The output device outputs a result of the counted cycles, which are indicative of damage to an a remaining useful life of the switch mode power supply.

  7. Low-voltage, high-extinction-ratio, Mach-Zehnder silicon optical modulator for CMOS-compatible integration.

    Science.gov (United States)

    Ding, Jianfeng; Chen, Hongtao; Yang, Lin; Zhang, Lei; Ji, Ruiqiang; Tian, Yonghui; Zhu, Weiwei; Lu, Yangyang; Zhou, Ping; Min, Rui

    2012-01-30

    We demonstrate a carrier-depletion Mach-Zehnder silicon optical modulator, which is compatible with CMOS fabrication process and works well at a low driving voltage. This is achieved by the optimization of the coplanar waveguide electrode to reduce the electrical signal transmission loss. At the same time, the velocity and impedance matching are both considered. The 12.5 Gbit/s data transmission experiment of the fabricated device with a 2-mm-long phase shifter is performed. The driving voltages with the swing amplitudes of 1 V and 2 V and the reverse bias voltages of 0.5 V and 0.8 V are applied to the device, respectively. The corresponding extinction ratios are 7.67 and 12.79 dB.

  8. Analysis of three-phase rectifiers with AC-side switches and interleaved three-phase voltage-source converters

    Science.gov (United States)

    Miller, Stephanie Katherine Teixeira

    Of all the alternative and renewable energy sources, wind power is the fastest growing alternative energy source with a total worldwide capacity of over 93 GW as of the end of 2007. However, making wind energy a sustainable and reliable source of electricity doesn't come without its set of challenges. As the wind turbines increase in size and turbine technology moves towards off-shore wind farms and direct drive transmission, the need for a reliable and efficient power electronics interface to convert the variable-frequency variable-magnitude output of the wind turbine's generator into the fixed-frequency fixed-magnitude voltage of the utility grid is critical. This dissertation investigates a power electronics interface envisioned to operate with an induction generator-based variable-speed wind turbine. The research conclusions and the interface itself are applicable to a variety of applications, including uninterruptible power supplies, industrial drives, and power quality applications, among others. The three-phase PWM rectifiers with ac-side bidirectional switches are proposed as the rectification stage of the power electronics interface. Modulation strategies are proposed for the rectifiers and the operation of the rectifiers in conjunction with an induction generator is demonstrated. The viability of using these rectifiers in place of the standard three-phase voltage-source converter is analyzed by comparing losses and common-mode voltage generation of the two topologies. Parallel three-phase voltage-source converter modules operated in an interleaved fashion are proposed for the inversion stage of the power electronics interface. The interleaved three-phase voltage-source converters are analyzed by deriving analytical models for the common-mode voltage, ac phase current, and dc-link current to reveal their spectra and the harmonic cancellation effects of interleaving. The practical problem of low frequency circulating current in parallel voltage

  9. Investigating Enhancement Mode Gallium Nitride Power FETs in High Voltage, High Frequency Soft Switching Converters

    DEFF Research Database (Denmark)

    Nour, Yasser; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2016-01-01

    An increased attention has been detected to develop smaller and lighter high voltage power converters in the range of 50V to 400V domain. The main applications for these converters are mainly focused for Power over Ethernet (PoE), LED lighting and AC adapters. This work will discuss a study...

  10. System of High Voltage Control and Sample Switch based on GTAF

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Qi-wei; HE; Guo-zhu; PENG; Meng; SHI; Bin; RUAN; Xi-chao; ZHOU; Zu-ying; ZHU; Xing-hua

    2015-01-01

    Gamma-ray total absorption facility(GTAF)is composed of 40pieces of BaF2detector.According to the requirements of the experiment,the amplitude of each detector output signal must be consistent,therefore,independent voltageneed to be provided for each detector unit.We use VISyN 1458 high voltage power supply,

  11. Investigating Enhancement Mode Gallium Nitride Power FETs in High Voltage, High Frequency Soft Switching Converters

    DEFF Research Database (Denmark)

    Nour, Yasser; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2016-01-01

    An increased attention has been detected to develop smaller and lighter high voltage power converters in the range of 50V to 400V domain. The main applications for these converters are mainly focused for Power over Ethernet (PoE), LED lighting and AC adapters. This work will discuss a study of us...

  12. Switch wear leveling

    Science.gov (United States)

    Wu, Hunter; Sealy, Kylee; Gilchrist, Aaron

    2015-09-01

    An apparatus for switch wear leveling includes a switching module that controls switching for two or more pairs of switches in a switching power converter. The switching module controls switches based on a duty cycle control technique and closes and opens each switch in a switching sequence. The pairs of switches connect to a positive and negative terminal of a DC voltage source. For a first switching sequence a first switch of a pair of switches has a higher switching power loss than a second switch of the pair of switches. The apparatus includes a switch rotation module that changes the switching sequence of the two or more pairs of switches from the first switching sequence to a second switching sequence. The second switch of a pair of switches has a higher switching power loss than the first switch of the pair of switches during the second switching sequence.

  13. Optimizing Design of Breakdown Voltage to Eliminate Back Gate Bias Effect in Silicon-on-Insulator Diode Using Low Doping Buried Layer

    Institute of Scientific and Technical Information of China (English)

    H0 Chi-Hon; LIAO Chen-Nan; CHIEN Feng-Tso; TSAI Yao-Tsung

    2009-01-01

    This work presents the optimal design of a silicon-on-insulator (SOI) diode structure to eliminate the back gate bias effect and to improve breakdown voltage. The SOI structure is characterized by inserting a silicon low doping buried layer (LDBL) between the silicon layer and the buried oxide layer. The LDBL thickness is a key parameter that affects the strong inversion condition of the back MOS capacitor of the new SOI diode. The optimal LDBL thickness in the SOI diode is 2.65μm. The LDBL shielding layer improved the breakdown voltage.

  14. Design of photonic phased array switches using nano electromechanical systems on silicon-on-insulator integration platform

    Science.gov (United States)

    Hussein, Ali Abdulsattar

    This thesis presents an introduction to the design and simulation of a novel class of integrated photonic phased array switch elements. The main objective is to use nano-electromechanical (NEMS) based phase shifters of cascaded under-etched slot nanowires that are compact in size and require a small amount of power to operate them. The structure of the switch elements is organized such that it brings the phase shifting elements to the exterior sides of the photonic circuits. The transition slot couplers, used to interconnect the phase shifters, are designed to enable biasing one of the silicon beams of each phase shifter from an electrode located at the side of the phase shifter. The other silicon beam of each phase shifter is biased through the rest of the silicon structure of the switch element, which is taken as a ground. Phased array switch elements ranging from 2x2 up to 8x8 multiple-inputs/multiple-outputs (MIMO) are conveniently designed within reasonable footprints native to the current fabrication technologies. Chapter one presents the general layout of the various designs of the switch elements and demonstrates their novel features. This demonstration will show how waveguide disturbances in the interconnecting network from conventional switch elements can be avoided by adopting an innovative design. Some possible applications for the designed switch elements of different sizes and topologies are indicated throughout the chapter. Chapter two presents the design of the multimode interference (MMI) couplers used in the switch elements as splitters, combiners and waveguide crossovers. Simulation data and design methodologies for the multimode couplers of interest are detailed in this chapter. Chapter three presents the design and analysis of the NEMS-operated phase shifters. Both simulations and numerical analysis are utilized in the design of a 0°-180° capable NEMS-operated phase shifter. Additionally, the response of some of the designed photonic phased

  15. SIMULATION ANALYSIS ON PROPORTIONAL INTEGRAL AND DERIVATIVE CONTROL OF CLOSED LOOP DC MOTOR DRIVE WITH BIPOLAR VOLTAGE SWITCHING

    Directory of Open Access Journals (Sweden)

    P. Karpagavalli

    2013-01-01

    Full Text Available This study presents the performance of a new four quadrant single phase DC drive closed loop system controlled by proportional integral and derivative controller with Pulse Width Modulation (PWM full bridge DC-DC converter using bipolar voltage switching. The proposed method is found to be more efficient in improving the step response characteristics such as reducing the settling time, rise time, steady state error and maximum overshoot in speed response of the closed loop DC motor drive and also reduced total harmonics distortion in the AC line current when compared to open loop system. The proposed topologies were simulated using MATLAB/Simulink software package and the results were obtained.

  16. Effect of Copper and Silicon on Al-5%Zn Alloy as a Candidate Low Voltage Sacrificial Anode

    Science.gov (United States)

    Pratesa, Yudha; Ferdian, Deni; Togina, Inez

    2017-05-01

    One common method used for corrosion protection is a sacrificial anode. Sacrificial anodes that usually employed in the marine environment are an aluminum alloy sacrificial anode, especially Al-Zn-In. However, the electronegativity of these alloys can cause corrosion overprotection and stress cracking (SCC) on a high-strength steel. Therefore, there is a development of the sacrificial anode aluminum low voltage to reduce the risk of overprotection. The addition of alloying elements such as Cu, Si, and Ge will minimize the possibility of overprotection. This study was conducted to analyze the effect of silicon and copper addition in Al-5Zn. The experiment started from casting the sacrificial anode aluminum uses electrical resistance furnace in a graphite crucible in 800°C. The results alloy was analyzed using Optical emission spectroscopy (OES), Differential scanning calorimetry, electrochemical impedance spectroscopy, and metallography. Aluminum alloy with the addition of a copper alloy is the most suitable and efficient to serve as a low-voltage sacrificial anode aluminum. Charge transfer resistivity of copper is smaller than silicon which indicates that the charge transfer between the metal and the electrolyte is easier t to occur. Also, the current potential values in coupling with steel are also in the criteria range of low-voltage aluminum sacrificial anodes.

  17. Design and fabrication of sub-μs silicon-on-insulator thermo-optic 4×4 switch matrix

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A rearrangeable nonblocking silicon-on-insulator-based thermo-optic 4×4 switch matrix with spot size converters (SSCs) and a new driving circuit are designed and fabricated. The introduction of a spot size converter (SSC) has decreased the insertion loss to less than 10dB and the new driving circuit has improved the response speed to less than 1μs.

  18. Total Ionizing Dose Test of Microsemi's Silicon Switching Transistors JANTXV2N2222AUB and 2N2907AUB

    Science.gov (United States)

    Campola, M.; Freeman, B.; Yau, K.

    2017-01-01

    Microsemi's silicon switching transistors, JANTXV2N2222AUB and 2N2907AUB, were tested for total ionizing dose (TID) response beginning on July 11, 2016. This test served as the radiation lot acceptance test (RLAT) for the lot date code (LDC) tested. Low dose rate (LDR) irradiations were performed in this test so that the device susceptibility to enhanced low dose rate sensitivity (ELDRS) could be determined.

  19. XMEGA-Based Implementation of Four-Switch, Three-Phase Voltage Source Inverter-Fed Induction Motor Drive

    Directory of Open Access Journals (Sweden)

    Abolfazl Halavei Niasar

    2013-02-01

    Full Text Available Induction motors offer many advantages tools, and therefore are becoming very popular industrially and commercially. This paper presents the implementation of Xmega microcontroller based PWM inverter controlled of four-switch three phase voltage source inverter (FSTPI fed induction motor drive. The reduction of the number of power switches from six to four improves the cost effectiveness, volume-compactness and reliability of the three phase inverters in addition to less complexity of control algorithms and reduced interface circuits. Simulation and experimental work are carried out and results presented to demonstrate the feasibility of the proposed approach. Simulation is carried out using SIMULINK and in experimental work, a prototype model is built to verify the simulation results. XMEGA microcontroller (XMEGA64A3 is used to generate the PWM pulses with a new algorithm for FSTPI to drive a 5 hp, 3-phase induction motor. Experimental and simulation results show that the proposed drive system provides a fast speed response and good disturbance rejection capability.

  20. A New Four States High Deflection Low Actuation Voltage Electrostatic Mems Switch for RF Applications

    CERN Document Server

    Robin, Renaud; Segueni, Karim; Millet, Olivier; Buchaillot, Lionel

    2008-01-01

    This paper presents a new electrostatic MEMS (MicroElectroMechanical System) based on a single high reliability totally free flexible membrane. Using four electrodes, this structure enables four states which allowed large deflections (4$\\mu$m) with low actuation voltage (7,5V). This design presents also a good contact force and improve the restoring force of the structure. As an example of application, a Single Pole Double Throw (SPDT) for 24GHz applications, based on this design, has been simulated.

  1. Developing Physics-based Models for 4H-SiC High Voltage Power Switches---MOSFET, IGBT and GTO

    Science.gov (United States)

    Lee, Meng-Chia

    The goal of this dissertation is to develop physics-based equivalent circuit models for 15kV˜20kV 4H-SiC power switches. The previous modeling works will be reviewed, and the parameter extraction methodologies will be discussed. MOSFET is modeled using a voltage-controlled current source for channel current and three nonlinear capacitances for the transient behavior. The high electron saturation velocity and its effect on the saturation current level will also be discussed. Final model has been implemented in Simulink/Matlab, and the execution time for the turn-on and off transient is less than 1 second. IGBT Analytical model that translate the local excess carrier to the diffusion capacitance will be derived first and implemented in a sub-circuit manner into Simulink/Matlab. A novel parameter extraction technique---Excess carrier density mapping (ECDM)---using inductive switching waveforms is introduced. The execution time of the model is about 7 seconds and 2 seconds for a turn-off and turn-on transient, respectively. IGBTs with two-zone drift region for slowing down the turn-off dv/dt are also proposed based on the developed analytical model. Finally, 4H-SiC p-GTO model based on the IGBT one is developed. Region-wise lifetimes throughout the drift region was observed when using the proposed ECDM technique. Simulated waveforms using region-wise lifetime have shown better fitting results than the case using constant lifetime. The difference between n-type and p-type ambipolar switches will be discussed and compared using the developed models.

  2. The correlation of open-circuit voltage with bandgap in amorphous silicon-based {ital pin} solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Crandall, R.S. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States); Schiff, E.A. [Department of Physics, Syracuse University, Syracuse, New York 13244-1130 (United States)

    1996-01-01

    We briefly review the correlation of open-circuit voltages {ital V}{sub OC} with the bandgap of the intrinsic layer in amorphous silicon based {ital pin} solar cells. We discuss two mechanisms which limit {ital V}{sub OC}: intrinsic layer recombination, and the built-in potential {ital V}{sub BI}. In particular we discuss Li{close_quote}s proposal that the open-circuit voltages in higher bandgap cells ({ital E}{sub G}{gt}1.9 eV) are {ital V}{sub BI}-limited. Based on computer simulations of {ital pin} solar cells we propose that {ital V}{sub BI} limitation occurs when the recombination limit to {ital V}{sub OC} exceeds the cell{close_quote}s field-reversal voltage {ital V}{sub R}. For {ital a}-Si:H based cells this field-reversal voltage occurs at about {ital V}{sub BI}-0.3 V. This proposal would account for the observation that {ital V}{sub BI} limitation occurs for {ital V}{sub OC} significantly smaller than {ital V}{sub BI}. {copyright} {ital 1996 American Institute of Physics.}

  3. Ferroresonance in 220/420-kV-voltage transformers during switching; Ferroresonanz an 220/420-kV-Spannungswandlern bei Schalthandlungen

    Energy Technology Data Exchange (ETDEWEB)

    Braeunlich, R. [Fachkommission fuer Hochspannungsfragen (FKH), Zurich (Switzerland); Daeumling, H. [Ritz Messwandler (Germany). Bereich Entwicklung, Qualitaetsmanagement und Prueffelder; Hofstetter, M. [Elektrizitaetswerk der Stadt Zuerich (EWZ) (Switzerland). Abt. Projektierung und Bau Unterwerke; Prucker, U. [Trench-Germany GmbH (Germany); Schmid, J. [Trench Switzerland AG, Basel (Switzerland); Minkner, R. [Trench Switzerland AG, Basel (Switzerland); Haefely AG, Basel (Switzerland); Hochschule fuer Technik und Informatik, Burgdorf (Switzerland); Schlierf, H.W. [RWE Transportnetz Strom GmbH (Germany). Abt. fuer Hochspannungsbetriebsmittel

    2007-07-15

    Ferroresonances occure usually in small from grid decoupled parts of a switch device and its circuits. Due to capacitive coupling by the grid voltage a manyfold of complex and nonlinear oscillations are affected if the transformer kernel is saturated. In this contribution a complex three-phase ferroresonance process is described and remedy measures are presented. (GL)

  4. A New Control Method of a Resonant Switched-Capacitor Converter and the Application for Balancing of the Split DC Voltages in a Multilevel Inverter

    Science.gov (United States)

    Sano, Kenichiro; Fujita, Hideaki

    This paper proposes a new voltage-balancing circuit for the split dc voltages in a diode-clamped five-level inverter. The proposed circuit is based on a resonant switched-capacitor converter (RSCC), which consists of two half-bridge inverters, a resonant inductor and a resonant capacitor. A new phase-shift control of the RSCC is proposed to improve voltage balancing performance. Theoretical analysis reveals the rating of the RSCC and stored energy in the resonant inductor. Experimental results confirm the reduction of the inductor to one tenth in volume as compared to a conventional voltage-balancing circuit based on buck-boost topology. Moreover, the proposed phase-shift control has demonstrated that it is possible to eliminate the voltage deviation between the dc capacitors.

  5. High-voltage switching by means of a stack of thyristors

    Science.gov (United States)

    Meddens, B. J. H.; Delmee, P. F. M.; van Amersfoort, P. W.

    1996-02-01

    The use of a stack of 32 thyristors for production of a 20-kV pulse is reported. The pulse power is 50 MW and the pulse duration is 25 μs. The thyristor stack serves as a line swith for a pulse-forming network which provides the input power for a 20-MW klystron. The klystron provides the rf power for the infrared free-electron laser FELIX. The choice of thyristors is motivated by the required relative voltage-stability during the pulse of 0.08%. Also the pulse-to-pulse reproducibility is required to stay within 0.08%. Detailed design considerations and operational results are presented.

  6. A new static induction thyristor with high forward blocking voltage and excellent switching performances

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Caizhen; Wang Yongshun; Liu Chunjuan; Wang Zaixing, E-mail: wangysh@mail.lzjtu.c [School of Electronic and Information Engineering, Lanzhou Jiaotong University, Lanzhou 730070 (China)

    2010-03-15

    A new static induction thyristor (SITH) with a strip anode region and p{sup -} buffer layer structure (SAP{sup -}B) has been successfully designed and fabricated. This structure is composed of a p{sup -} buffer layer and lightly doped n{sup -} regions embedded in the p{sup +}-emitter. Compared with the conventional structure of a buried-gate with a diffused source region (DSR buried-gate), besides the simple fabrication process, the forward blocking voltage of this SITH has been increased to 1600 V from the previous value of 1000 V, the blocking gain increased from 40 to 70, and the turn-off time decreased from 0.8 to 0.4 {mu}s. (semiconductor integrated circuits)

  7. Study of High-Voltage Inverter Synchronous Switching Function%高压变频器同步投切功能的研究

    Institute of Scientific and Technical Information of China (English)

    徐卫青; 杨志勇; 冯骥

    2014-01-01

    Introduction was made to the basic principle and realizing method of main circuit of high-voltage inverter synchronous switching system. This paper gave the synchronous switching flow chart and its protective logic. On switching, by using software phase-locked loop technique, inverter output voltage was adjusted, as well as the grid voltage phase, amplitude, frequency in unifor-mity, then the switching between inverter and power was accomplished by the PLC and automatic switch. The test has verified the feasibility of the method, with higher site application value.%介绍了高压变频同步投切系统主回路的基本原理及实现方法,给出了同步切换流程及其保护逻辑,切换时利用软件锁相环技术调整变频器输出电压与电网电压的相位、幅值、频率一致,然后通过可编程控制器及自动开关完成变频与工频间的切换,试验验证了该方法的可行性,具有较高的现场应用价值。

  8. Regulation of the forming process and the set voltage distribution of unipolar resistance switching in spin-coated CoFe2O4 thin films.

    Science.gov (United States)

    Mustaqima, Millaty; Yoo, Pilsun; Huang, Wei; Lee, Bo Wha; Liu, Chunli

    2015-01-01

    We report the preparation of (111) preferentially oriented CoFe2O4 thin films on Pt(111)/TiO2/SiO2/Si substrates using a spin-coating process. The post-annealing conditions and film thickness were varied for cobalt ferrite (CFO) thin films, and Pt/CFO/Pt structures were prepared to investigate the resistance switching behaviors. Our results showed that resistance switching without a forming process is preferred to obtain less fluctuation in the set voltage, which can be regulated directly from the preparation conditions of the CFO thin films. Therefore, instead of thicker film, CFO thin films deposited by two times spin-coating with a thickness about 100 nm gave stable resistance switching with the most stable set voltage. Since the forming process and the large variation in set voltage have been considered as serious obstacles for the practical application of resistance switching for non-volatile memory devices, our results could provide meaningful insights in improving the performance of ferrite material-based resistance switching memory devices.

  9. A wide bandgap silicon carbide (SiC) gate driver for high-temperature and high-voltage applications

    Energy Technology Data Exchange (ETDEWEB)

    Lamichhane, Ranjan [University of Arkansas; Ericson, Milton Nance [ORNL; Frank, Steven Shane [ORNL; BRITTONJr., CHARLES L. [Oak Ridge National Laboratory (ORNL); Marlino, Laura D [ORNL; Mantooth, Alan [University of Arkansas; Francis, Matt [APEI, Inc.; Shepherd, Dr. Paul [University of Arkansas; Glover, Dr. Michael [University of Arkansas; Podar, Mircea [ORNL; Perez, M [University of Arkansas; Mcnutt, Tyler [APEI, Inc.; Whitaker, Mr. Bret [APEI, Inc.; Cole, Mr. Zach [APEI, Inc.

    2014-01-01

    Limitations of silicon (Si) based power electronic devices can be overcome with Silicon Carbide (SiC) because of its remarkable material properties. SiC is a wide bandgap semiconductor material with larger bandgap, lower leakage currents, higher breakdown electric field, and higher thermal conductivity, which promotes higher switching frequencies for high power applications, higher temperature operation, and results in higher power density devices relative to Si [1]. The proposed work is focused on design of a SiC gate driver to drive a SiC power MOSFET, on a Cree SiC process, with rise/fall times (less than 100 ns) suitable for 500 kHz to 1 MHz switching frequency applications. A process optimized gate driver topology design which is significantly different from generic Si circuit design is proposed. The ultimate goal of the project is to integrate this gate driver into a Toyota Prius plug-in hybrid electric vehicle (PHEV) charger module. The application of this high frequency charger will result in lighter, smaller, cheaper, and a more efficient power electronics system.

  10. Threshold-Voltage-Shift Compensation and Suppression Method Using Hydrogenated Amorphous Silicon Thin-Film Transistors for Large Active Matrix Organic Light-Emitting Diode Displays

    Science.gov (United States)

    Oh, Kyonghwan; Kwon, Oh-Kyong

    2012-03-01

    A threshold-voltage-shift compensation and suppression method for active matrix organic light-emitting diode (AMOLED) displays fabricated using a hydrogenated amorphous silicon thin-film transistor (TFT) backplane is proposed. The proposed method compensates for the threshold voltage variation of TFTs due to different threshold voltage shifts during emission time and extends the lifetime of the AMOLED panel. Measurement results show that the error range of emission current is from -1.1 to +1.7% when the threshold voltage of TFTs varies from 1.2 to 3.0 V.

  11. Effective variable switching point predictive current control for ac low-voltage drives

    Science.gov (United States)

    Stolze, Peter; Karamanakos, Petros; Kennel, Ralph; Manias, Stefanos; Endisch, Christian

    2015-07-01

    This paper presents an effective model predictive current control scheme for induction machines driven by a three-level neutral point clamped inverter, called variable switching point predictive current control. Despite the fact that direct, enumeration-based model predictive control (MPC) strategies are very popular in the field of power electronics due to their numerous advantages such as design simplicity and straightforward implementation procedure, they carry two major drawbacks. These are the increased computational effort and the high ripples on the controlled variables, resulting in a limited applicability of such methods. The high ripples occur because in direct MPC algorithms the actuating variable can only be changed at the beginning of a sampling interval. A possible remedy for this would be to change the applied control input within the sampling interval, and thus to apply it for a shorter time than one sample. However, since such a solution would lead to an additional overhead which is crucial especially for multilevel inverters, a heuristic preselection of the optimal control action is adopted to keep the computational complexity at bay. Experimental results are provided to verify the potential advantages of the proposed strategy.

  12. Development of Thin Film Amorphous Silicon Tandem Junction Based Photocathodes Providing High Open-Circuit Voltages for Hydrogen Production

    Directory of Open Access Journals (Sweden)

    F. Urbain

    2014-01-01

    Full Text Available Hydrogenated amorphous silicon thin film tandem solar cells (a-Si:H/a-Si:H have been developed with focus on high open-circuit voltages for the direct application as photocathodes in photoelectrochemical water splitting devices. By temperature variation during deposition of the intrinsic a-Si:H absorber layers the band gap energy of a-Si:H absorber layers, correlating with the hydrogen content of the material, can be adjusted and combined in a way that a-Si:H/a-Si:H tandem solar cells provide open-circuit voltages up to 1.87 V. The applicability of the tandem solar cells as photocathodes was investigated in a photoelectrochemical cell (PEC measurement set-up. With platinum as a catalyst, the a-Si:H/a-Si:H based photocathodes exhibit a high photocurrent onset potential of 1.76 V versus the reversible hydrogen electrode (RHE and a photocurrent of 5.3 mA/cm2 at 0 V versus RHE (under halogen lamp illumination. Our results provide evidence that a direct application of thin film silicon based photocathodes fulfills the main thermodynamic requirements to generate hydrogen. Furthermore, the presented approach may provide an efficient and low-cost route to solar hydrogen production.

  13. Polycrystalline silicon thin-film solar cells prepared by layered laser crystallization with 540 mV open circuit voltage

    Energy Technology Data Exchange (ETDEWEB)

    Plentz, Jonathan, E-mail: jonathan.plentz@ipht-jena.de [Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena (Germany); Experimental Physics I, Institute of Physics, Ilmenau University of Technology, Weimarer Str. 32, 98693 Ilmenau (Germany); Andrä, Gudrun; Gawlik, Annett; Höger, Ingmar; Jia, Guobin; Falk, Fritz [Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena (Germany)

    2014-07-01

    Polycrystalline silicon thin film solar cells on a glass substrate are investigated. The solar cell layer structure was generated by a two-step process in which first a 100–600 nm thin seed layer is formed by diode laser crystallization of electron beam evaporated amorphous silicon. In a second step this layer is epitaxially thickened to 2–3.5 μm by layered laser crystallization. In this process further amorphous silicon is deposited and in situ repeatedly is irradiated by excimer laser pulses. The polycrystalline layer consists of grains several hundreds of microns long and several tens of microns wide and it contains a p{sup +}–p–n{sup +} doping profile. After deposition a rapid thermal annealing and hydrogen passivation steps follow. The back and front contacts are prepared after mesa structuring. The influence of the seed layer thickness on the solar cell performance was investigated. In addition, the absorber contamination due to the background pressure during absorber deposition and its influence on the short circuit current density was investigated. The best parameters reached for various solar cells are 540 mV open circuit voltage, 20.3 mA/cm{sup 2} short circuit current density (without light trapping), 75% fill factor, and 5.2% efficiency. - Highlights: • Layered laser crystallization leads to grain sizes of 10–300 μm on glass. • Open circuit voltage of 540 mV and efficiency of 5.2% are achieved. • Short circuit current is influenced by background pressure during deposition. • Short circuit current density of 20.3 mA/cm{sup 2} is reached without light trapping. • Progress requires pressures below 10{sup −7} hPa and deposition rates over 100 nm/min.

  14. Ultra-compact and wide-spectrum-range thermo-optic switch based on silicon coupled photonic crystal microcavities

    CERN Document Server

    Zhang, Xingyu; Chung, Chi-Jui; Pan, Zeyu; Yan, Hai; Chen, Ray T

    2016-01-01

    We design, fabricate, and experimentally demonstrate a compact thermo-optic gate switch comprising a 3.78 um-long coupled L0-type photonic crystalmicrocavities on a silicon-on-insulator substrate. A nanohole is inserted in the center of each individual L0 photonic crystalmicrocavity. Coupling between identical microcavities gives rise to bonding and anti-bonding states of the coupled photonic molecules. The coupled photonic crystalmicrocavities are numerically simulated and experimentally verified with a 6 nm-wide flat-bottom resonance in its transmission spectrum, which enables wider operational spectrum range than microring resonators. An integrated micro-heater is in direct contact with the silicon core to efficiently drive the device. The thermo-optic switch is measured with an optical extinction ratio of 20 dB, an on-off switching power of 18.2 mW, a thermo-optic tuning efficiency of 0.63 nm/mW, a rise time of 14.8 us, and a fall time of 18.5 us. The measured on-chip loss on the transmission band is as l...

  15. Ultra-compact and wide-spectrum-range thermo-optic switch based on silicon coupled photonic crystal microcavities

    Science.gov (United States)

    Zhang, Xingyu; Chakravarty, Swapnajit; Chung, Chi-Jui; Pan, Zeyu; Yan, Hai; Chen, Ray T.

    2015-11-01

    We design, fabricate, and experimentally demonstrate a compact thermo-optic gate switch comprising a 3.78 μm-long coupled L0-type photonic crystal microcavities on a silicon-on-insulator substrate. A nanohole is inserted in the center of each individual L0 photonic crystal microcavity. Coupling between identical microcavities gives rise to bonding and anti-bonding states of the coupled photonic molecules. The coupled photonic crystal microcavities are numerically simulated and experimentally verified with a 6 nm-wide flat-bottom resonance in its transmission spectrum, which enables wider operational spectrum range than microring resonators. An integrated micro-heater is in direct contact with the silicon core to efficiently drive the device. The thermo-optic switch is measured with an optical extinction ratio of 20 dB, an on-off switching power of 18.2 mW, a thermo-optic tuning efficiency of 0.63 nm/mW, a rise time of 14.8 μs, and a fall time of 18.5 μs. The measured on-chip loss on the transmission band is as low as 1 dB.

  16. Microheater-integrated silicon coupled photonic crystal microcavities for low-power thermo-optic switching over a wide spectrum

    Science.gov (United States)

    Zhang, Xingyu; Chakravarty, Swapnajit; Chung, Chi-Jui; Pan, Zeyu; Yan, Hai; Chen, Ray T.

    2016-03-01

    We design, fabricate and experimentally demonstrate a compact thermo-optic gate switch comprising a 3.78μm-long coupled L0-type photonic crystal microcavities on a silicon-on-insulator substrate. A nanohole is inserted in the center of each individual L0 photonic crystal microcavity. Coupling between identical microcavities gives rise to bonding and antibonding states of the coupled photonic molecules. The coupled photonic crystal microcavities are numerically simulated and experimentally verified with a 6nm-wide flat-bottom resonance in its transmission spectrum, which enables wider operational spectrum range than microring resonators. An integrated micro-heater is in direct contact with the silicon core to efficiently drive the device. The thermo-optic switch is measured with an optical extinction ratio of 20dB, an on-off switching power of 18.2mW, a therm-optic tuning efficiency of 0.63nm/mW, a rise time of 14.8μsec and a fall time of 18.5μsec. The measured on-chip loss on the transmission band is as low as 1dB.

  17. Research on the Influence of Switching Frequency on Low-Frequency Oscillation in the Voltage-Controlled Buck-Boost Converter

    Directory of Open Access Journals (Sweden)

    Faqiang Wang

    2011-01-01

    Full Text Available The influence of switching frequency on the low-frequency oscillation in the voltage-controlled buck-boost converter is studied in this paper. Firstly, the mathematical model of this system is derived. And then, a glimpse at the influence of switching frequency on the low-frequency oscillation in this system by MATLAB/Simulink is given. The improved averaged model of the system is established, and the corresponding theoretical analysis is presented. It is found that the switching frequency has an important influence on the low-frequency oscillation in the system, that is, the low-frequency oscillation is easy to occur when the switching frequency is low. Finally, the effectiveness of the improved averaged model and the theoretical analysis are confirmed by circuit experiment.

  18. Temperature influence and reset voltage study of bipolar resistive switching behaviour in ZrO2 thin films

    Indian Academy of Sciences (India)

    Ying Li; Gaoyang Zhao; Jian Su; Erfeng Shen; Yang Ren

    2014-05-01

    We have fabricated ZrO2 thin films by sol–gel deposition and annealed them at 300, 500 and 700 °C. Reproducible - curves can be obtained for the device Cu/ZrO2/ATO which is measured at room temperature (300 K). During the RESET operation, L and H values can be controlled by the RESET voltage. Moreover, the Cu/ZrO2/ATO device which the ZrO2 thin film annealed at 300 °C can be measured as resistive switching sweeps at 200, 100 and 50 K. It was found that the ratio of off/on reduced when the measured temperature decreased. When the - measurement temperature decreases, on decreases obviously which is typical for electronic transportation in a Cu metal. It is indicated that the Cu metallic conduction filament has been formed in the ZrO2 films. Besides, the microstructure by high resolution transmission electrical microscopy (HRTEM) was also investigated.

  19. Development and Investigation of Tungsten Copper Sintered Parts for Using in Medium and High Voltage Switching Devices

    Science.gov (United States)

    Lungu, M. V.; Lucaci, M.; Tsakiris, V.; Brătulescu, A.; Cîrstea, C. D.; Marin, M.; Pătroi, D.; Mitrea, S.; Marinescu, V.; Grigore, F.; Tălpeanu, D.; Stancu, N.; Godeanu, P.; Melnic, C.

    2017-06-01

    Abstract Tungsten-copper (W-Cu) sintered parts with 75 wt.% W, 24 wt.% Cu and 1 wt.% Ni for using as arcing contacts in medium and high voltage switching devices were developed successfully by powder metallurgy (PM) techniques. Sintered parts with diameter of 50±0.5 mm and height of 6±0.5 mm were manufactured by pressing-sintering-infiltration (P-S-I) and spark plasma sintering (SPS) at sintering temperature of 1150°C, and 1050°C, respectively. Physical, chemical, electrical, thermal and mechanical properties of the samples were investigated. Microstructure was analyzed by optical microscopy and scanning electron microscopy. Material properties were influenced by the consolidation processes. The best results were achieved by SPS process. The relative density was more than 95 %, Vickers hardness HV1/15 was over 227, elastic modulus was over 143 GPa, and homogeneous microstructure was revealed. These good properties can contribute to higher lifetime of arcing contacts under severe working conditions.

  20. Ultra-Low Power High Temperature and Radiation Hard Complementary Metal-Oxide-Semiconductor (CMOS) Silicon-on-Insulator (SOI) Voltage Reference

    OpenAIRE

    El Hafed Boufouss; Francis, Laurent A.; Valeriya Kilchytska; Pierre Gérard; Pascal Simon; Denis Flandre

    2013-01-01

    This paper presents an ultra-low power CMOS voltage reference circuit which is robust under biomedical extreme conditions, such as high temperature and high total ionized dose (TID) radiation. To achieve such performances, the voltage reference is designed in a suitable 130 nm Silicon-on-Insulator (SOI) industrial technology and is optimized to work in the subthreshold regime of the transistors. The design simulations have been performed over the temperature range of -40–200 °C and for differ...

  1. Free-carrier contribution to all-optical switching in Mie-resonant hydrogenated amorphous silicon nanodisks

    Science.gov (United States)

    Vabishchevich, Polina P.; Shorokhov, Alexander S.; Shcherbakov, Maxim R.; Fedyanin, Andrey A.

    2016-03-01

    Conventionally, all-optical switching devices made out from bulk silicon and other semiconductors are limited by free-carrier relaxation time which spans from picoseconds to microseconds. In this work, we discuss the possibility to suppress the undesired long free-carrier relaxation in subwavelength dielectric nanostructures exhibiting localized magnetic Mie resonances. Numerical calculations show the unsymmetrical modification of the transmittance spectra of the nanodisks due the free carriers photo-injection. Such a spectral dependance allows to control temporal response of the nanostructure by varying the laser pulse spectum.

  2. Reconfigurable nonblocking 4-port silicon thermo-optic optical router based on Mach-Zehnder optical switches.

    Science.gov (United States)

    Yang, Lin; Xia, Yuhao; Zhang, Fanfan; Chen, Qiaoshan; Ding, Jianfeng; Zhou, Ping; Zhang, Lei

    2015-04-01

    We demonstrate a reconfigurable nonblocking 4-port silicon thermo-optic optical router based on Mach-Zehnder optical switches. For all optical links in its 9 routing states, the optical signal-to-noise ratios are larger than 15 dB in the wavelength range from 1525 to 1565 nm. Each optical link of the optical router can manipulate 50 wavelength-division-multiplexing channels with the data rate of 32 Gbps for each channel in the same wavelength range. Its average energy efficiency is about 16.3 fJ/bit, and its response time is about 19 μs.

  3. A Silicon-on-Insulator-Based Thermo-Optic Waveguide Switch with Low Insertion Loss and Fast Response

    Institute of Scientific and Technical Information of China (English)

    LI Yan-Ping; YU Jin-Zhong; CHEN Shao-Wu

    2005-01-01

    @@ A silicon-on-insulator-based thermo-optic waveguide switch integrated with spot size converters is designed and fabricated by inductively coupled plasma reactive ion etching. The device shows good characteristics, including low insertion loss of 8 ± 1 dB for wavelength 1530-1580nm and fast response times of 4.6 μs for rising edge and 1.9μs for falling edge. The extinction ratios of the two channels are 19.1 and 18 dB, respectively.

  4. Mach-Zehnder Interferometers with Asymmetric Modulation Arms in Applications of High Speed Silicon-on-Insulator Based Optical Switches

    Institute of Scientific and Technical Information of China (English)

    SUN Fei; YU Jin-Zhong

    2006-01-01

    @@ Modulation arms with different widths are introduced to Mach-Zehnder interferometers (MZIs) to obtain improved performance. Theoretical analysis and numerical simulation have shown that when the widths of the two arms are properly designed to achieve an inherent mπ/2 (m is an odd integer) optical phase difference between the arms, the asymmetric MZI presents higher modulation speed. Furthermore, the carrier-absorption induced divergence of insertion losses in silicon-on-insulator (SOI) based MZI optical switches can be obviously improved.

  5. Calculation Model for Current-voltage Relation of Silicon Quantum-dots-based Nano-memory

    Institute of Scientific and Technical Information of China (English)

    YANG Hong-guan; DAI Da-kang; YU Biao; SHANG Lin-lin; GUO You-hong

    2007-01-01

    Based on the capacitive coupling formalism, an analytic model for calculating the drain currents of the quantum-dots floating-gate memory cell is proposed. Using this model, one can calculate numerically the drain currents of linear, saturation and subthreshold regions of the device with/without charges stored on the floating dots. The read operation process of an n-channel Si quantum-dots floating-gate nano-memory cell is discussed after calculating the drain currents versus the drain to source voltages and control gate voltages in both high and low threshold states respectively.

  6. In-plane magnetic field effect on switching voltage and thermal stability in electric-field-controlled perpendicular magnetic tunnel junctions

    Science.gov (United States)

    Grezes, C.; Rojas Rozas, A.; Ebrahimi, F.; Alzate, J. G.; Cai, X.; Katine, J. A.; Langer, J.; Ocker, B.; Khalili Amiri, P.; Wang, K. L.

    2016-07-01

    The effect of in-plane magnetic field on switching voltage (Vsw) and thermal stability factor (Δ) are investigated in electric-field-controlled perpendicular magnetic tunnel junctions (p-MTJs). Dwell time measurements are used to determine the voltage dependence of the energy barrier height for various in-plane magnetic fields (Hin), and gain insight into the Hin dependent energy landscape. We find that both Vsw and Δ decrease with increasing Hin, with a dominant linear dependence. The results are reproduced by calculations based on a macrospin model while accounting for the modified magnetization configuration in the presence of an external magnetic field.

  7. Dynamics of threshold voltage shifts in organic and amorphous silicon field-effect transistors

    NARCIS (Netherlands)

    Mathijssen, Simon G. J.; Colle, Michael; Gomes, Henrique; Smits, Edsger C. P.; de Boer, Bert; McCulloch, Iain; Bobbert, Peter A.; de Leeuw, Dago M.; Cölle, Michael

    2007-01-01

    The electrical instability of organic field-effect transistors is investigated. We observe that the threshold-voltage shift (see figure) shows a stretched-exponential time dependence under an applied gate bias. The activation energy of 0.6 eV is common for our and all other organic transistors repor

  8. Performance, high voltage operation and radiation hardness of full-size ATLAS charge division silicon detectors with LHC electronics

    Science.gov (United States)

    Allport, P. P.; Booth, P. S. L.; Carter, J. R.; Goodrick, M. J.; Green, C.; Greenall, A.; Hanlon, M.; Hill, J. C.; Jackson, J. N.; Jones, T. J.; Martí i García, S.; Munday, D. J.; Murray, W.; Richardson, J. D.; Robinson, D.; Sheridan, A. E.; Smith, N. A.; Tyndel, M.; Wyllie, K.

    1998-02-01

    ATLAS silicon detectors designed for charge division read-out were produced during 1995 and have been extensively studied both in the laboratory and test beam at the CERN SPS. Data have been taken with the analogue read-out FELIX-128 chip and studies simulating other read-out architectures under consideration by ATLAS have been performed. To evaluate survival in the harsh environment of the LHC, detectors have been tested to high voltage, both before and after radiation damage by protons exceeding the expected charged hadron dose after 10 years of LHC operation. These tests have all employed analogue read-out to be sensitive to changes in noise and charge collection efficiency as a function of the detector damage.

  9. Correlation Between the Raman Crystallinity of p-Type Micro-Crystalline Silicon Layer and Open Circuit Voltage of n-i-p Solar Cells.

    Science.gov (United States)

    Jung, Junhee; Kim, Sunbo; Park, Jinjoo; Shin, Chonghoon; Pham, Duy Phong; Kim, Jiwoong; Chung, Sungyoun; Lee, Youngseok; Yi, Junsin

    2015-10-01

    This article mainly discusses the difference between p-i-n and n-i-p type solar cells. Their structural difference has an effect on cell performance, such as open circuit voltage and fill factor. Although the deposition conditions are the same for both p-i-n and n-i-p cases, the substrate layers for depositing p-type microcrystalline silicon layers differ. In n-i-p cells, the substrate layer is p-type amorphous silicon oxide layer; whereas, in p-i-n cells, the substrate layer is ZnO:Al. The interfacial change leads to a 12% difference in the crystallinity of the p-type microcrystalline silicon layers. When the p-type microcrystalline silicon layer's crystallinity was not sufficient to activate an internal electric field, the open circuit voltage and fill factor decreased 0.075 V and 7.36%, respectively. We analyzed this problem by comparing the Raman spectra, electrical conductivity, activation energy and solar cell performance. By adjusting the thickness of the p-type microcrystalline silicon layer, we increased the open circuit voltage of the n-i-p cell from 0.835 to 0.91 V.

  10. Simulation Study on the Open-Circuit Voltage of Amorphous Silicon p-i-n Solar Cells Using AMPS-1D

    Directory of Open Access Journals (Sweden)

    B.M. Omer

    2014-04-01

    Full Text Available AMPS-1D (Analysis of Microelectronic and Photonic Structure simulation program was used to simulate Amorphous Silicon p-i-n Solar Cell. The simulated result of illuminated current density-voltage characteristics was in a good agreement with experimental values. The dependence of the open-circuit voltage on the characteristics of the a-Si:H intrinsic layer was investigated. The simulation result shows that the open-circuit voltage does not depend on the thickness of the intrinsic layer. The open-circuit voltage decreases when the front contact barrier height is small or the energy gap of the intrinsic layer is small. The open-circuit voltage increases when the distribution of the tail states is sharp or the capture cross sections of these states are small.

  11. Avalanche mode of high-voltage overloaded p{sup +}–i–n{sup +} diode switching to the conductive state by pulsed illumination

    Energy Technology Data Exchange (ETDEWEB)

    Kyuregyan, A. S., E-mail: ask@vei.ru [Lenin All-Russia Electrical Engineering Institute (Russian Federation)

    2015-07-15

    A simple analytical theory of the picosecond switching of high-voltage overloaded p{sup +}–i–n{sup +} photodiodes to the conductive state by pulsed illumination is presented. The relations between the parameters of structure, light pulse, external circuit, and main process characteristics, i.e., the amplitude of the active load current pulse, delay time, and switching duration, are derived and confirmed by numerical simulation. It is shown that the picosecond light pulse energy required for efficient switching can be decreased by 6–7 orders of magnitude due to the intense avalanche multiplication of electrons and holes. This offers the possibility of using pulsed semiconductor lasers as a control element of optron pairs.

  12. A New Approach to High Efficincy in Isolated Boost Converters for High-Power Low-Voltage Fuel Cell Apllications

    DEFF Research Database (Denmark)

    Nymand, Morten; Andersen, Michael A. E.

    2008-01-01

    by the use of power MOSFETs fully rated for repetitive avalanche. Voltage rating of primary switches can now be reduced, significantly reducing switch on-state losses. Finally, silicon carbide rectifying diodes allow fast diode turn-off, further reducing losses. Test results from a 1.5 kW full-bridge boost...

  13. Isolated DC-DC Converter for Bidirectional Power Flow Controlling with Soft-Switching Feature and High Step-Up/Down Voltage Conversion

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2017-03-01

    Full Text Available In this paper, a novel isolated bidirectional DC-DC converter is proposed, which is able to accomplish high step-up/down voltage conversion. Therefore, it is suitable for hybrid electric vehicle, fuel cell vehicle, energy backup system, and grid-system applications. The proposed converter incorporates a coupled inductor to behave forward-and-flyback energy conversion for high voltage ratio and provide galvanic isolation. The energy stored in the leakage inductor of the coupled inductor can be recycled without the use of additional snubber mechanism or clamped circuit. No matter in step-up or step-down mode, all power switches can operate with soft switching. Moreover, there is a inherit feature that metal–oxide–semiconductor field-effect transistors (MOSFETs with smaller on-state resistance can be adopted because of lower voltage endurance at primary side. Operation principle, voltage ratio derivation, and inductor design are thoroughly described in this paper. In addition, a 1-kW prototype is implemented to validate the feasibility and correctness of the converter. Experimental results indicate that the peak efficiencies in step-up and step-down modes can be up to 95.4% and 93.6%, respectively.

  14. A fully on-chip three-terminal switched-capacitor DC-DC converter for low-voltage CMOS LSIs

    Science.gov (United States)

    Kojima, Yuta; Hirose, Tetsuya; Tsubaki, Keishi; Ozaki, Toshihiro; Asano, Hiroki; Kuroki, Nobutaka; Numa, Masahiro

    2016-04-01

    In this paper, we present a fully on-chip switched-capacitor DC-DC converter for low-voltage CMOS LSIs. The converter has three terminals of input, ground, and output, by developing control circuits with fully on-chip configuration. We employ an ultra low-power nanoampere bias current and voltage reference circuit to achieve ultra low-power dissipation of control circuits. It enables us to realize a highly efficient power conversion circuit at light-load-current applications. The converter achieves highly efficient and robust voltage conversion using a pulse frequency modulation control circuit and a start-up/fail-safe circuit. Measurement results demonstrated that the converter can convert a 3.0 V input into 1.2 V output successfully. The start-up and fail-safe operations were confirmed through the measurement. The efficiency was more than 50% in the range of 2-6 µA load current.

  15. Power electronic topology and switching-concept for identification of the grid impedance at medium-voltage-level; Leistungselektronisches Schaltungskonzept zur Identifikation der Netzimpedanz auf der Mittelspannungsebene

    Energy Technology Data Exchange (ETDEWEB)

    Do, Thanh Trung; Jordan, Michael; Langkowski, Hauke; Schulz, Detlef [Helmut-Schmidt-Univ., Hamburg (Germany). Professur fuer Elektrische Energiesysteme; Leutwyler, Reto [ABB Switzerland Ltd., Lenzburg (Switzerland). Semiconductors

    2011-07-01

    The grid impedance at a point of common coupling (PCC) is an important parameter for grid integration of Renewable Energies, because it determines the maximum input power capacity of the corresponding PCC. The grid impedance is time and frequency dependent, which makes an analytical or simulative identification challenging. Therefore in practise the data obtained from these calculations are often incorrect and do not reflect the real grid structure. In order to determine the grid impedance more accurately the Helmut-Schmidt-University is developing a novel measurement device to identify the time and frequency dependent grid impedance on the medium-voltage-level up to 20 kVrms. For the application in medium-voltage-grids a special switching concept with high voltage thyristors and innovative presspack-IGBTs has been developed in cooperation with ABB Switzerland Ltd./Semiconductors. This contribution presents the basic grid impedance measurement method and its realization with power electronic components. (orig.)

  16. Optical and Electrical Performance of MOS-Structure Silicon Solar Cells with Antireflective Transparent ITO and Plasmonic Indium Nanoparticles under Applied Bias Voltage

    Directory of Open Access Journals (Sweden)

    Wen-Jeng Ho

    2016-08-01

    Full Text Available This paper reports impressive improvements in the optical and electrical performance of metal-oxide-semiconductor (MOS-structure silicon solar cells through the incorporation of plasmonic indium nanoparticles (In-NPs and an indium-tin-oxide (ITO electrode with periodic holes (perforations under applied bias voltage. Samples were prepared using a plain ITO electrode or perforated ITO electrode with and without In-NPs. The samples were characterized according to optical reflectance, dark current voltage, induced capacitance voltage, external quantum efficiency, and photovoltaic current voltage. Our results indicate that induced capacitance voltage and photovoltaic current voltage both depend on bias voltage, regardless of the type of ITO electrode. Under a bias voltage of 4.0 V, MOS cells with perforated ITO and plain ITO, respectively, presented conversion efficiencies of 17.53% and 15.80%. Under a bias voltage of 4.0 V, the inclusion of In-NPs increased the efficiency of cells with perforated ITO and plain ITO to 17.80% and 16.87%, respectively.

  17. Optical and Electrical Performance of MOS-Structure Silicon Solar Cells with Antireflective Transparent ITO and Plasmonic Indium Nanoparticles under Applied Bias Voltage.

    Science.gov (United States)

    Ho, Wen-Jeng; Sue, Ruei-Siang; Lin, Jian-Cheng; Syu, Hong-Jang; Lin, Ching-Fuh

    2016-08-10

    This paper reports impressive improvements in the optical and electrical performance of metal-oxide-semiconductor (MOS)-structure silicon solar cells through the incorporation of plasmonic indium nanoparticles (In-NPs) and an indium-tin-oxide (ITO) electrode with periodic holes (perforations) under applied bias voltage. Samples were prepared using a plain ITO electrode or perforated ITO electrode with and without In-NPs. The samples were characterized according to optical reflectance, dark current voltage, induced capacitance voltage, external quantum efficiency, and photovoltaic current voltage. Our results indicate that induced capacitance voltage and photovoltaic current voltage both depend on bias voltage, regardless of the type of ITO electrode. Under a bias voltage of 4.0 V, MOS cells with perforated ITO and plain ITO, respectively, presented conversion efficiencies of 17.53% and 15.80%. Under a bias voltage of 4.0 V, the inclusion of In-NPs increased the efficiency of cells with perforated ITO and plain ITO to 17.80% and 16.87%, respectively.

  18. Effect of recombination on the open-circuit voltage of a silicon solar cell

    Science.gov (United States)

    Von Roos, O.; Landsberg, P. T.

    1985-01-01

    A theoretical study of the influence of band-band Auger, band-trap Auger, and the ordinary Shockley-Read-Hall mechanism for carrier recombination on the open-circuit voltage VOC of a solar cell is presented. Under reasonable assumptions for the magnitude of rate constants and realistic values for trap densities, surface recombination velocities and band-gap narrowing, the maximum VOC for typical back surface field solar cells is found to lie in the range between 0.61 and 0.72 V independent of base width.

  19. High frequency three-phase PWM grid connected drive using silicon-carbide switches

    DEFF Research Database (Denmark)

    Kouchaki, Alireza; Pedersen, Jacob Lykke; Nymand, Morten

    2016-01-01

    and with this compensation. The controller is designed for a 5 kW SiC based three-phase rectifier (switching frequency 50 kHz) connected to a 7.5kW SiC based inverter (switching frequency 32 kHz). Experimental results are also carried out to validate the operation of the controller under different operating conditions....... A failure test is also conducted to highlight the drawbacks of feedforward with high forward gain....

  20. Voltage-controlled low-energy switching of nanomagnets through Ruderman-Kittel-Kasuya-Yosida interactions for magnetoelectric device applications

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Bahniman, E-mail: bghosh@utexas.edu; Dey, Rik; Register, Leonard F.; Banerjee, Sanjay K. [Microelectronics Research Center, University of Texas at Austin, 10100 Burnet Road, Bldg. 160, Austin, Texas 78758 (United States)

    2016-07-21

    In this article, we consider through simulation low-energy switching of nanomagnets via electrostatically gated inter-magnet Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions on the surface of three-dimensional topological insulators, for possible memory and nonvolatile logic applications. We model the possibility and dynamics of RKKY-based switching of one nanomagnet by coupling to one or more nanomagnets of set orientation. Potential applications to both memory and nonvolatile logic are illustrated. Sub-attojoule switching energies, far below conventional spin transfer torque (STT)-based memories and even below CMOS logic appear possible. Switching times on the order of a few nanoseconds, comparable to times for STT switching, are estimated for ferromagnetic nanomagnets, but the approach also appears compatible with the use of antiferromagnets which may allow for faster switching.

  1. Voltage-controlled low-energy switching of nanomagnets through Ruderman-Kittel-Kasuya-Yosida interactions for magnetoelectric device applications

    Science.gov (United States)

    Ghosh, Bahniman; Dey, Rik; Register, Leonard F.; Banerjee, Sanjay K.

    2016-07-01

    In this article, we consider through simulation low-energy switching of nanomagnets via electrostatically gated inter-magnet Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions on the surface of three-dimensional topological insulators, for possible memory and nonvolatile logic applications. We model the possibility and dynamics of RKKY-based switching of one nanomagnet by coupling to one or more nanomagnets of set orientation. Potential applications to both memory and nonvolatile logic are illustrated. Sub-attojoule switching energies, far below conventional spin transfer torque (STT)-based memories and even below CMOS logic appear possible. Switching times on the order of a few nanoseconds, comparable to times for STT switching, are estimated for ferromagnetic nanomagnets, but the approach also appears compatible with the use of antiferromagnets which may allow for faster switching.

  2. Novel Folding Large-Scale Optical Switch Matrix with Total Internal Reflection Mirrors on Silicon-on-Insulator by Anisotropy Chemical Etching

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-Wei; YU Jin-Zhong; CHEN Shao-Wu

    2005-01-01

    A compact optical switch matrix was designed, in which light circuits were folded by total internal reflective (TIR) mirrors. Two key elements, 2 × 2 switch and TIR mirror, have been fabricated on silicon-on-insulator wafer by anisotropy chemical etching. The 2 × 2 switch showed very low power consumption of 140mW and avery high speed of 8 ± 1 μs. An improved design for the TIR mirror was developed, and the fabricated mirror with smooth and vertical reflective facet showed low excess loss of 0.7 ± 0.3 dB at 1.55μm.

  3. Ultrafast all-optical switching and error-free 10 Gbit/s wavelength conversion in hybrid InP-silicon on insulator nanocavities using surface quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Bazin, Alexandre; Monnier, Paul; Beaudoin, Grégoire; Sagnes, Isabelle; Raj, Rama [Laboratoire de Photonique et de Nanostructures (CNRS UPR20), Route de Nozay, Marcoussis 91460 (France); Lenglé, Kevin; Gay, Mathilde; Bramerie, Laurent [Université Européenne de Bretagne (UEB), 5 Boulevard Laënnec, 35000 Rennes (France); CNRS-Foton Laboratory (UMR 6082), Enssat, BP 80518, 22305 Lannion Cedex (France); Braive, Rémy; Raineri, Fabrice, E-mail: fabrice.raineri@lpn.cnrs.fr [Laboratoire de Photonique et de Nanostructures (CNRS UPR20), Route de Nozay, Marcoussis 91460 (France); Université Paris Diderot, Sorbonne Paris Cité, 75207 Paris Cedex 13 (France)

    2014-01-06

    Ultrafast switching with low energies is demonstrated using InP photonic crystal nanocavities embedding InGaAs surface quantum wells heterogeneously integrated to a silicon on insulator waveguide circuitry. Thanks to the engineered enhancement of surface non radiative recombination of carriers, switching time is obtained to be as fast as 10 ps. These hybrid nanostructures are shown to be capable of achieving systems level performance by demonstrating error free wavelength conversion at 10 Gbit/s with 6 mW switching powers.

  4. 32 × 32 silicon electro-optic switch with built-in monitors and balanced-status units

    Science.gov (United States)

    Qiao, Lei; Tang, Weijie; Chu, Tao

    2017-02-01

    To construct large-scale silicon electro-optical switches for optical interconnections, we developed a method using a limited number of power monitors inserted at certain positions to detect and determine the optimum operating points of all switch units to eliminate non-uniform effects arising from fabrication errors. We also introduced an optical phase bias to one phase-shifter arm of a Mach–Zehnder interferometer (MZI)-type switch unit to balance the two operation statuses of a silicon electro-optical switch during push–pull operation. With these methods, a 32 × 32 MZI-based silicon electro-optical switch was successfully fabricated with 180-nm complementary metal–oxide–semiconductor (CMOS) process technology, which is the largest scale silicon electro-optical switch to the best of our knowledge. At a wavelength of 1520 nm, the on-chip insertion losses were 12.9 to 16.5 dB, and the crosstalk ranged from ‑17.9 to ‑24.8 dB when all units were set to the ‘Cross’ status. The losses were 14.4 to 18.5 dB, and the crosstalk ranged from ‑15.1 to ‑19.0 dB when all units were in the ‘Bar’ status. The total power consumptions of the 32 × 32 switch were 247.4 and 542.3 mW when all units were set to the ‘Cross’ and ‘Bar’ statuses, respectively.

  5. Ultrafast Silicon-based Modulators using Optical Switching of Vanadium Dioxide

    Science.gov (United States)

    2014-12-04

    the current through the device [23]. At a certain threshold voltage, a metallic current path is formed through the VO2 and a significant jump in...pulse measurement shows purely thermal recovery while the 3V pulse measurement shows a distinct jump when the voltage is turned off, followed by a...achieved with a coupler that is only 10 microns in length, significantly more compact than traditional tapered coupler designs. (a) (b) (c) (d

  6. Tailored Voltage Waveform Deposition of Microcrystalline Silicon Thin Films from Hydrogen-Diluted Silane and Silicon Tetrafluoride: Optoelectronic Properties of Films

    Science.gov (United States)

    Johnson, Erik V.; Pouliquen, Sylvain; Delattre, Pierre-Alexandre; Booth, Jean-Paul

    2012-08-01

    The use of tailored voltage waveforms (TVW's) to excite a plasma for the deposition of thin films of hydrogenated microcrystalline silicon (µc-Si:H) has been shown to be an effective technique to decouple mean ion bombardment energy (IBE) from injected power. In this work, we examine the changes in material properties controlled by this technique through Raman scattering and spectroscopic ellipsometry for films deposited from H2-diluted SiH4, and we examine the electrical properties of such films using temperature dependent conductivity. As the laboratory-scale deposition system used had neither a load lock nor an oxygen filter in the H2 line, accidental O-doping was observed for the µc-Si:H films. We investigated suppression of this doping by adding varying amounts of SiF4, and using an SiF4/Ar pre-etch step to clean the reactor. This technique is shown to be effective in decreasing the accidental doping of the films, and intrinsic µc-Si:H films are produced with an activation energy of up to 0.55 eV. As well, an important difference in the amorphous-to-microcrystalline transition is observed once SiF4 is included in the gas mixture.

  7. Voltage control of metal-insulator transition and non-volatile ferroelastic switching of resistance in VOx/PMN-PT heterostructures.

    Science.gov (United States)

    Nan, Tianxiang; Liu, Ming; Ren, Wei; Ye, Zuo-Guang; Sun, Nian X

    2014-08-04

    The central challenge in realizing electronics based on strongly correlated electronic states, or 'Mottronics', lies in finding an energy efficient way to switch between the distinct collective phases with a control voltage in a reversible and reproducible manner. In this work, we demonstrate that a voltage-impulse-induced ferroelastic domain switching in the (011)-oriented 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) substrates allows a robust non-volatile tuning of the metal-insulator transition in the VOx films deposited onto them. In such a VOx/PMN-PT heterostructure, the unique two-step electric polarization switching covers up to 90% of the entire poled area and contributes to a homogeneous in-plane anisotropic biaxial strain, which, in turn, enables the lattice changes and results in the suppression of metal-insulator transition in the mechanically coupled VOx films by 6 K with a resistance change up to 40% over a broad range of temperature. These findings provide a framework for realizing in situ and non-volatile tuning of strain-sensitive order parameters in strongly correlated materials, and demonstrate great potentials in delivering reconfigurable, compactable, and energy-efficient electronic devices.

  8. 20 kA PFN capacitor bank with solid-state switching. [pulse forming network for plasma studies

    Science.gov (United States)

    Posta, S. J.; Michels, C. J.

    1973-01-01

    A compact high-current pulse-forming network capacitor bank using paralleled silicon controlled rectifiers as switches is described. The maximum charging voltage of the bank is 1kV and maximum load current is 20 kA. The necessary switch equalization criteria and performance with dummy load and an arc plasma generator are described.

  9. Radiation Testing of a Low Voltage Silicone Nuclear Power Plant Cable.

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Robert

    2014-08-01

    This report summarizes the results generated in FY13 for cable insulation in support of DOE's Light Water Reactor Sustainability (LWRS) Program, in collaboration with the US- Argentine Binational Energy Working Group (BEWG). A silicone (SiR) cable, which was stored in benign conditions for %7E30 years, was obtained from Comision Nacional de Energia Atomica (CNEA) in Argentina. Physical property testing was performed on the as-received cable. This cable was artificially aged to assess behavior with additional analysis. SNL observed appreciable tensile elongation values for all cable insulations received, indicative of good mechanical performance. Of particular note, the work presented here provides correlations between measured tensile elongation and other physical properties that may be potentially leveraged as a form of condition monitoring (CM) for actual service cables. It is recognized at this point that the polymer aging community is still lacking the number and types of field returned materials that are desired, but SNL -- along with the help of others -- is continuing to work towards that goal. This work is an initial study that should be complimented with location- mapping of environmental conditions of CNEA plant conditions (dose and temperature) as well as retrieval, analysis, and comparison with in-service cables.

  10. Radiation Testing of a Low Voltage Silicone Nuclear Power Plant Cable.

    Energy Technology Data Exchange (ETDEWEB)

    White II, Gregory Von; Schroeder, John Lee.; Sawyer, Patricia Sue.; Wichhart, Derek; Mata, Guillermo Adrian; Zorrilla, Jorge; Bernstein, Robert

    2014-09-01

    This report summarizes the results generated in FY13 for cable insulation in support of the Department of Energy's Light Water Reactor Sustainability (LWRS) Program, in collaboration with the US-Argentine Binational Energy Working Group (BEWG). A silicone (SiR) cable, which was stored in benign conditions for %7E30 years, was obtained from Comision Nacional de Energia Atomica (CNEA) in Argentina with the approval of NA-SA (Nucleoelectrica Argentina Sociedad Anonima). Physical property testing was performed on the as-received cable. This cable was artificially aged to assess behavior with additional analysis. SNL observed appreciable tensile elongation values for all cable insulations received, indicative of good mechanical performance. Of particular note, the work presented here provides correlations between measured tensile elongation and other physical properties that may be potentially leveraged as a form of condition monitoring (CM) for actual service cables. It is recognized at this point that the polymer aging community is still lacking the number and types of field returned materials that are desired, but Sandia National Laboratories (SNL) -- along with the help of others -- is continuing to work towards that goal. This work is an initial study that should be complimented with location-mapping of environmental conditions of Argentinean plant conditions (dose and temperature) as well as retrieval, analysis, and comparison with in- service cables.

  11. Recent trends in silicon carbide device research

    Directory of Open Access Journals (Sweden)

    Munish Vashishath

    2008-08-01

    Full Text Available Silicon carbide (SiC has revolutionised semiconductor power device performance. It is a wide band gap semiconductor with an energy gap wider than 2eV and possesses extremely high power, high voltage switching characteristics and high thermal, chemical and mechanical stability. The SiC wafers are available in 6H, 4H, 2H and 3C polytypes. Because of its wide band gap, the leakage current of SiC is many orders of magnitude lower than that of silicon. Also, forward resistance of SiC power devices is approximately 200 times lower than that of conventional silicon devices. The breakdown voltage of SiC is 8-10 times higher than that of silicon. In this paper, silicon carbide Schottky barrier diodes, power MOSFETs, UMOSFET, lateral power MOSFET, SIT (static induction transistor, and nonvolatile memories are discussed along with their characteristics and applications.

  12. Threshold resistance switching in silicon-rich SiO x thin films

    Science.gov (United States)

    Chen, Da; Huang, Shi-Hua

    2016-11-01

    Si-rich SiO x and amorphous Si clusters embedded in SiO x films were prepared by the radio-frequency magnetron cosputtering method and high-temperature annealing treatment. The threshold resistance switching behavior was achieved from the memory mode by continuous bias sweeping in all films, which was caused by the formation of clusters due to the local overheating under a large electric field. Besides, the I-V characteristics of the threshold switching showed a dependence on the annealing temperature and the SiO x thickness. In particular, formation and rupture of conduction paths is considered to be the switching mechanism for the 39 nm-SiO x film, while for the 78 nm-SiO x film, adjusting of the Schottky barrier height between insulator and semiconductor is more reasonable. This study demonstrates the importance of investigation of both switching modes in resistance random access memory. Project supported by the Open Project Program of Surface Physics Laboratory (National Key Laboratory) of Fudan University, China (Grant No. KF2015_02), the Open Project Program of National Laboratory for Infrared Physics, Chinese Academy of Sciences (Grant No. M201503), Zhejiang Provincial Science and Technology Key Innovation Team, China (Grant No. 2011R50012), and Zhejiang Provincial Key Laboratory, China (Grant No. 2013E10022).

  13. Tailored Voltage Waveforms in an SF6 /O2 discharge: slope asymmetry and its effect on surface nanotexturing of silicon

    Science.gov (United States)

    Fischer, G.; Drahi, E.; Poulain, G.; Bruneau, B.; Johnson, E. V.

    2016-09-01

    The nanotexturing of the surface of a crystalline silicon (c-Si) wafer for improved photovoltaic performance can be achieved through the use of a SF6 /O2 capacitively coupled reactive ion etching plasma. In this study, we attempt to modify the texturing conditions by taking advantage of slope asymmetries of Tailored Voltage Waveform (TVW) excitation. We show that TVW shapes resembling ``sawtooths'', presenting a large slope asymmetry, induce high ionization asymmetries in the discharge, and that the dominance of this effect strongly depends on both gas mixture and pressure. These asymmetries have been previously observed in other electronegative gas and are due to differing plasma sheath dynamics at powered and grounded electrode in a discharge operating in drift-ambipolar mode. The texturing of c-Si in SF6 /O2 occurs through competing mechanisms, including etching by fluorine radicals and in-situ deposition of micro-masking species. The relative fluxes of etching and passivating species are expected to be strongly varied due to the plasma asymmetry. Morphological and optical characterization of textured c-Si surfaces will give more insight into both the plasma properties and the mechanisms involved in dry nanotexturing. This project has been supported by the French Government in the frame of the program of investment for the future (Programme d'Investissement d'Avenir - ANR-IEED-002-01).

  14. Improvement of the voltage-controlled negative resistance of a porous silicon emitter using cathode reduction and electro-pretreatment

    Science.gov (United States)

    He, Li; Zhang, Xiaoning; Wang, Wenjiang; Zhao, Xiaoning

    2016-09-01

    A new composite treatment method combining cathode reduction (CR) and electro-pretreatment (EP) is proposed to improve the voltage-controlled negative resistance (VCNR) of porous silicon (PS) emitters. Four groups of PS emitters were treated, with nothing, CR, EP, and a combination of CR and EP, during different preparation stages. The experimental results indicate that both CR and EP improved the VCNR property and the emission characteristics of the PS emitter. The most favorable results occurred for the electron emitter treated with a combination of CR-EP. A peak-to-valley current ratio of 1.06 and an emission current density of 150 µA cm-2, which are the lowest value and approximately twice that of other samples, respectively, were obtained. In addition, the operating stability of the PS emitter also improved significantly compared with the two methods alone. Scanning electron microscopy, atomic force microscopy, and energy dispersive x-ray spectrometry results demonstrate that the improvements of the VCNR and the emission characteristics of PS emitters are due to the content variation of defects, impurities, and unstable microstructures in the PS layer under the influence of CR and EP. The mechanism of VCNR behavior is explained by a proposed energy band model, which is consistent with the experimental results.

  15. Solid-state Marx based two-switch voltage modulator for the On-Line Isotope Mass Separator accelerator at the European Organization for Nuclear Research.

    Science.gov (United States)

    Redondo, L M; Silva, J Fernando; Canacsinh, H; Ferrão, N; Mendes, C; Soares, R; Schipper, J; Fowler, A

    2010-07-01

    A new circuit topology is proposed to replace the actual pulse transformer and thyratron based resonant modulator that supplies the 60 kV target potential for the ion acceleration of the On-Line Isotope Mass Separator accelerator, the stability of which is critical for the mass resolution downstream separator, at the European Organization for Nuclear Research. The improved modulator uses two solid-state switches working together, each one based on the Marx generator concept, operating as series and parallel switches, reducing the stress on the series stacked semiconductors, and also as auxiliary pulse generator in order to fulfill the target requirements. Preliminary results of a 10 kV prototype, using 1200 V insulated gate bipolar transistors and capacitors in the solid-state Marx circuits, ten stages each, with an electrical equivalent circuit of the target, are presented, demonstrating both the improved voltage stability and pulse flexibility potential wanted for this new modulator.

  16. Resistance switching memory operation using the bistability in current-voltage characteristics of GaN/AlN resonant tunneling diodes

    Science.gov (United States)

    Nagase, Masanori; Takahashi, Tokio; Shimizu, Mitsuaki

    2016-10-01

    Resistance switching memory operations using the bistability in the current-voltage (I-V) characteristics of GaN/AlN resonant tunneling diodes (RTDs) were investigated to realize an ultrafast nonvolatile memory operating at a picosecond time scale. Resistance switching memory operations based on electron accumulation due to intersubband transitions and electron release due to tunneling current were demonstrated with high reproducibility at room temperature when the leakage of electrons accumulating in the quantum well from the deep level in the AlN barrier was suppressed. A nonvolatile memory for the processor core in a normally off computing system is expected to be realized using the bistability in the I-V characteristics of GaN/AlN RTDs.

  17. Design of Railway Switch Indication Voltage Collector Based on CAN Bus%基于CAN总线的道岔表示电压采集器设计

    Institute of Scientific and Technical Information of China (English)

    易黎丽

    2015-01-01

    Aimed at the deficiency exists in traditional measurement of railway switch indication voltage, design railway switch indication voltage collector based on CAN bus. Based on ARM microprocessor technology, according to the collection and calculation of railway switch indication voltage signal, explicated the design of hardware and software, and the implementation of the system, and experimented and discussed in range of -25~70℃. The results show that the collector has the features of high accuracy, small size, easy installation and low power consumption, and can meet the needs of railway field monitoring applications, and has certain actual application value and popularization significance.%针对传统铁路道岔表示电压检测方案存在的不足,设计了一款基于CAN总线的道岔表示电压采集器.基于ARM微处理器技术,根据道岔表示电压信号的采集与计算,给出了系统的硬件设计、软件设计及系统实现方案,并在-25~70℃范围内进行实验验证和讨论.结果表明:该采集器具有精度高、体积小、易于安装和功耗低等特点,能满足铁路现场监测应用需求,具有一定的实际应用价值和推广意义.

  18. High voltage pulse generator

    Science.gov (United States)

    Fasching, George E.

    1977-03-08

    An improved high-voltage pulse generator has been provided which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of a first one of the rectifiers connected between the first and second of the plurality of charging capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. Alternate circuits are provided for controlling the application of the charging voltage from a charging circuit to be applied to the parallel capacitors which provides a selection of at least two different intervals in which the charging voltage is turned "off" to allow the SCR's connecting the capacitors in series to turn "off" before recharging begins. The high-voltage pulse-generating circuit including the N capacitors and corresponding SCR's which connect the capacitors in series when triggered "on" further includes diodes and series-connected inductors between the parallel-connected charging capacitors which allow sufficiently fast charging of the capacitors for a high pulse repetition rate and yet allow considerable control of the decay time of the high-voltage pulses from the pulse-generating circuit.

  19. Switched-capacitor multiply-by-two amplifier with reduced capacitor mismatches sensitivity and full swing sample signal common-mode voltage

    Institute of Scientific and Technical Information of China (English)

    Xu Xinnan; Yao Suying; Xu Jiangtao; Nie Kaiming

    2012-01-01

    A switched-capacitor amplifier with an accurate gain of two that is insensitive to component mismatch is proposed.This structure is based on associating two sets of two capacitors in cross series during the amplification phase.This circuit permits the common-mode voltage of the sample signal to reach full swing.Using the chargecomplement technique,the proposed amplifier can reduce the impact of parasitic capacitors on the gain accuracy effectively.Simulation results show that as sample signal common-mode voltage changes,the difference between the minimum and maximum gain error is less than 0.03%.When the capacitor mismatch is increased from 0 to 0.2%,the gain error is deteriorated by 0.00015 %.In all simulations,the gain of amplifier is 69 dB.

  20. Active battery charge equalization with voltage controlled vertical buck-boost switching cells%电压控制Buck-Boost电池充电均衡器

    Institute of Scientific and Technical Information of China (English)

    谢莉; 蒋伟

    2015-01-01

    本文研究了储能设备的均衡充电方法。采用垂直 Buck-Boost 电路作为均衡器的基本交换单元。在不同的负载条件下,用状态空间平均法和小信号分析法获得对应的开关单元模型。通过电压控制均衡方案,利用电压环补偿设备端电压,电流内环使得电荷定向移动。实验结果表明,所提出的均衡器能实现电荷最快移动并能有效地收敛到零电压差,本地控制器能快速、准确地跟踪参考值。%This paper investigates the active charge equalization method for energy storage devices. The vertical buck-boost circuit is used as the basic switching cell of this equalizer. By applying state-space averaging and small signal analysis, the model of the switching cell is obtained under different load condition. A voltage controlled equalization scheme is presented, which is featured with voltage loop to equalize the terminal voltage and inner current loop for charge shuttling. The simulation and experimental results indicate that the proposed equalizer can effectively converge to zero voltage difference condition by offering a maximized charge shuttling effort, and the local controller can react fast and precisely to the reference command.

  1. OPTIMIZATION OF SURFACE RESISTIVITY AND RELATIVE PERMITTIVITY OF SILICONE RUBBER FOR HIGH VOLTAGE APPLICATION USING RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    N.N. Ali

    2017-06-01

    Full Text Available Silicone Rubber (SiR is considered as one of the most established insulator in High Voltage (HV industry. SiR possess a great function ability such as its lighter weight, great heat resistance and substantial electrical insulation properties. Dynamic research were performed all around the world in order to explore the unique insulating behavior of SiR but very little are done on the optimization of SiR in term of their processing parameters and formulation. In this work, four materials and processing factors were introduced; A: Alumina Trihydrate (ATH, B: Dicumyl-Peroxide (DCP, C: mixing speed and D: mixing time in order to analyze its contribution towards improving the surface resistivity and relative permittivity of SIR rubber. The factors range were set based on prior screening and are defined as; ATH (10 – 50 pphr, Dicumyl Peroxide (0.50 -1.50 pphr, speed of mixer (40 – 70 rpm and mixing period (5 – 10 mins which were then varied accordingly to produce an overall 19 samples of SiR blends. The testing results were analyzed using statistical Design of Experiment (DOE by applying two level full factorial from Design Expert Software (v10 to discover the inter-correlation between the factors studied and benefaction of each factor in improving both surface resistivity and relative permittivity responses of produced SiR blends. The model analysis on surface resistivity shows the coefficient of determination R2 value of 88.72% while the one for relative permittivity shows R2 value of 82.34 %. Combination of both dependent variables had yielded an optimization suggestion for SiR formulation and processing strategy of ATH: 50 pphr, DCP: 0.50 pphr, mixing speed: 70 rpm and mixing period: 10 mins with the desirability level of 0.835. The optimized formulation had resulted in the production of SiR blend with the characteristic of surface resistivity of 1.02039x10^14 Ω/sq and relative permittivity of 4.0231, respectively. In conclusion, it can be

  2. On the application of permanent magnet control technology in low voltage switch%论低压开关中永磁控制技术的应用

    Institute of Scientific and Technical Information of China (English)

    龚荣福

    2016-01-01

    为了克服传统低压开关电动控制系统中所存在的诸如接触器主触头被烧、短路情况下断路器无法正常将电路分断、电机保护功能难以充分发挥等问题,可以通过永磁控制技术的应用加以实现.本文重点就低压开关的电磁控制技术进行探讨,以供参考.%In orderto overcome the traditional low voltage switch electric control system such as the main contact of the contactor is burned,short circuit breaker can not be normal circuit breaking,it is difficult to give full play to the function of protecting the motor and other issues, through permanent magnet control technology to be realized.This paper focuses on the low voltage switch electromagnetic control technology for reference.

  3. 提高RF MEMS开关速度的电压控制方法%Voltage Control Approach to Improve the Speed of RF MEMS Switches

    Institute of Scientific and Technical Information of China (English)

    邓成; 鲍景富; 凌源; 杜亦佳; 赵兴海; 郑英彬

    2012-01-01

    针对RF MEMS开关释放时间过长的问题,提出了一种电压控制方法有效地缩短了开关的释放时间,提高了开关的速度.这种方法无需修改器件设计,仅需要调整偏置电压变化形式,用线性压降替代传统的阶跃压降,就能有效抑制MEMS梁在释放过程中的振动.给出了这种方法的相关理论、等效模型及仿真结果.由ANSYS仿真结果可知,在标准大气压下,采用28 μs单段线性压降后,梁的释放时间从103 μs缩短到62.5 μs;采用26 μs双段线性压降后,梁的释放时间进一步缩短到26 μs,仅为原来的1/4,即开关速度约为原来的4倍.%The voltage control approach was presented to shorten the release time of the RF MEMS switch effectively, and the switching speed was improved. This method can inhibit the MEMS beam vibration in the release process effectively, which does not need to modify the device design, only need to adjust the bias voltage changing form and replace the traditional step representation pressure drop with the linear pressure drop. The correlation theory, equivalent model and simulation result of the approach were given. The ANSYS simulation results indicate that in the standard atmospheric pressure, the beam release time reduces from 103 jxs to 62. 5 ^s with 28 /is single ramped bias voltage drop? And the beam release time furtherly reduces to 26 /us with 26 pis double ramped bias voltage drops, which is a quarter of the original release time, that is, the speed of the switch is about four times of the original speed.

  4. Design and performance characteristics of an electromagnetic interference shielded enclosure for high voltage Pockels cell switching system

    Indian Academy of Sciences (India)

    A K Sharma; K K Mishra; M Raghuramaiah; P A Naik; P D Gupta

    2007-06-01

    An electro-magnetic interference noise shielding enclosure for Pockels cells for high speed synchronized switching has been set-up and tested. The shielding effectiveness of the aluminum enclosures housing the Pockels cells and the electronic circuitry has been measured using a high impedance probe and is found to be $\\sim 50 dB$. This ensures a noise-free and synchronized electro-optic switching in an Nd:glass re-generative amplifier of chirped pulse amplification based table top terawatt laser system.

  5. 一种新颖的零电压开关全桥逆变器%Novel zero voltage switching full-bridge inverter

    Institute of Scientific and Technical Information of China (English)

    王艺翰; 凌志斌; 李睿; 蔡旭

    2014-01-01

    A novel zero voltage switching full⁃bridge inverter circuit is proposed. Only an active⁃clamp soft⁃switc⁃hing branch into the single H⁃bridge inverter circuit’ s dc link side is added, which can achieve zero⁃voltage switc⁃hing ( ZVS) of all switching devices, and inhibit the anti⁃parallel diode reverse recovery current of the main switc⁃hing devices to reduce the inverter switching losses and reverse recovery loss. This inverter can use common Pulse Width Modulation ( PWM) . At the same time the inverter can use less devices and simple structure. A detailed a⁃nalysis of the soft switching process is given, and theoretically calculate the requirement of the soft⁃switching branch. The operational waveforms of the inverter at positive half⁃cycle and the stage analysis of the inverter at posi⁃tive half⁃cycle are given to help understanding. Before the testing machine is built, the Saber simulation software is carried out to verify the correctness of the theoretical analysis. At last a 300W testing machine is built for experi⁃ment to test and verify.%提出了一种新颖的零电压开关全桥逆变器电路,在单H桥逆变电路的直流侧增加有源箝位软开关支路,可以实现所有开关管的零电压开通,同时由于谐振电感的存在,还可以抑制主开关管的反并联二极管反向恢复电流,从而降低逆变器的开通损耗和反向恢复损耗。本文较为详细地分析了电路实现软开关的各个过程,并从理论上计算了软开关实现条件,最后搭建了300 W的实验样机进行了实验验证。

  6. Study of microwave-induced phase switches from the finite voltage state in Bi2Sr2CaCu2Oy intrinsic Josephson junctions

    Science.gov (United States)

    Kitano, Haruhisa; Yamaguchi, Ayami; Takahashi, Yusaku; Kakehi, Daiki; Ayukawa, Shin-ya

    2017-07-01

    We study the microwave-induced phase switches from the finite voltage state for the underdamped intrinsic Josephson junctions (IJJs) made of Bi2Sr2CaCu2Oy (Bi2212). We observe the resonant double-peak structure in the switching current distribution at low temperatures. This feature is successfully explained by a quantum mechanical model where the strong microwave field effectively suppresses the potential barrier for the phase escape from a potential well and the macroscopic quantum tunneling (MQT) is resonantly enhanced. The detailed analyses considering the effects of multiple phase retrapping processes after the phase escape strongly suggest that the intense microwave field suppresses the energy-level spacing in the potential well, by effectively decreasing the fluctuation-free critical current and the Josephson plasma frequency. This effect also reduces the number of photons required for the multiphoton transition between the ground and the first excited states, making it possible to observe the energy level quantization in the MQT state. The temperature dependence of the resonance peak emerging in the switching rate clearly demonstrates that the quantized energy state can be survived up to ~10 K, which is much higher than a crossover temperature predicted by the conventional Caldeira-Leggett theory.

  7. Medium voltage switch rooms supporting the internal arc test; Cubiculos de media tensao que suportam o ensaio de arco interno

    Energy Technology Data Exchange (ETDEWEB)

    Cintra, Paulo de Brito [Light Servicos de Eletricidade SA, Rio de Janeiro, RJ (Brazil). E-mail: paulocintra@lightrio.com.br; Costa, Eleison S. [Centro de Pesquisas de Energia Eletrica, Rio de Janeiro, RJ (Brazil); Tanakai, Osmar [Siemens Ltda., Sao Paulo, SP (Brazil)

    1999-07-01

    This paper presents the trends and standards for project of construction of shielded switchgear and control gear aiming the switch room capability of supporting an internal arc, and shows the research and development of new solutions resulting from the project and maintenance engineering, aiming the reduction of the failure possibilities and guarantee the personal safety even they occurs.

  8. Five-port silicon optical router based on Mach—Zehnder optical switches for photonic networks-on-chip

    Science.gov (United States)

    Yunchou, Zhao; Hao, Jia; Jianfeng, Ding; Lei, Zhang; Xin, Fu; Lin, Yang

    2016-11-01

    With the continuous development of integrated circuits, the performance of the processor has been improved steadily. To integrate more cores in one processor is an effective way to improve the performance of the processor, while it is impossible to further improve the property of the processor by only increasing the clock frequency. For a processor with integrated multiple cores, its performance is determined not only by the number of cores, but also by communication efficiency between them. With more processor cores integrated on a chip, larger bandwidths are required to establish the communication among them. The traditional electrical interconnect has gradually become a bottleneck for improving the performance of multiple-core processors due to its limited bandwidth, high power consumption, and long latency. The optical interconnect is considered as a potential way to solve this issue. The optical router is the key device for realizing the optical interconnect. Its basic function is to achieve the data routing and switching between the local node and the multi-node. In this paper we present a five-port optical router for Mesh photonics network-on-chip. A five-port optical router composed of eight thermally tuned silicon Mach—Zehnder optical switches is demonstrated. The experimental spectral responses indicate that the optical signal-to-noise ratios of the optical router are over 13 dB in the wavelength range of 1525-1565 nm for all of its 20 optical links. Each optical link can manipulate 50 wavelength channels with the channel spacing of 100 GHz and the data rate of 32 Gbps for each wavelength channel in the same wavelength range. The lowest energy efficiency of the optical router is 43.4 fJ/bit. Project supported by the National High Technology Research and Development Program of China (Nos. 2015AA010103, 2015AA010901) and the National Natural Science Foundation of China (Nos. 61575187, 61235001, 61505198, 61377067).

  9. Hybrid switch for resonant power converters

    Science.gov (United States)

    Lai, Jih-Sheng; Yu, Wensong

    2014-09-09

    A hybrid switch comprising two semiconductor switches connected in parallel but having different voltage drop characteristics as a function of current facilitates attainment of zero voltage switching and reduces conduction losses to complement reduction of switching losses achieved through zero voltage switching in power converters such as high-current inverters.

  10. Voltage-Responsive Controlled Release Film with Cargo Release Self-Monitoring Property Based on Hydrophobicity Switching.

    Science.gov (United States)

    Jiao, Xiangyu; Li, Yanan; Li, Fengyu; Sun, Ruijuan; Wang, Wenqian; Wen, Yongqiang; Song, Yanlin; Zhang, Xueji

    2017-03-16

    Herein, voltage-responsive controlled release film was constructed by grafting ferrocene on the mesoporous inverse opal photonic crystal (mIOPC). The film achieved free-blockage controlled release and realized the monitoring of cargo release without external indicator. Free-blockage was attributed to the voltage switchable nanovalves which undergo hydrophobic-to-hydrophilic transition when applying voltage. Monitoring of cargo release was attributed to the optical property of mIOPC, the bandgap of mIOPC had a red shift when the solution invaded in. The film was hydrophobic enough to stop solution intrusion. Once the voltage was applied, the film became hydrophilic, leading to invasion of the solution. As a result, the cargos were released and the bandgap of mIOPC was red-shifted. Therefore, in this paper both a free-blockage controlled release film and a release sensing system was prepared. The study provides new insights into highly effective controlled release and release sensing without indicator.

  11. Design and implementation of a bidirectional current-controlled voltage-regulated DC-DC switched-mode converter

    CSIR Research Space (South Africa)

    Coetzer, A

    2016-01-01

    Full Text Available The design and implementation of a bidirectional current-controlled voltage-regulated DC-DC converter is presented. The converter is required to connect a battery of electrochemical cells (the battery) to an asynchronous motor-drive unit via a...

  12. Analysis of bias voltage scan data recorded with hybrid Timepix1 silicon pixel assemblies at the DESY testbeam

    CERN Document Server

    Maimon, Shir

    2014-01-01

    This report will present results from the analysis of bias voltage scans in Timepix1 testbeam data. Three assemblies of varying sensor thickness were used to collect data. The effect of the bias voltage on charge sharing, in particular cluster size, was investigated and found to have a significant impact. The effect of the bias voltage on energy collection was also studied, leading to estimates for the depletion voltage, donor concentration, mobility and resistivity of each assembly. Finally, the effect of the bias voltage on the two-hit cluster resolution and detection efficiency was investigated. This report contains extracts from a longer document (LCD-OPEN-2014-001).

  13. Ultra-low power high temperature and radiation hard complementary metal-oxide-semiconductor (CMOS) silicon-on-insulator (SOI) voltage reference.

    Science.gov (United States)

    Boufouss, El Hafed; Francis, Laurent A; Kilchytska, Valeriya; Gérard, Pierre; Simon, Pascal; Flandre, Denis

    2013-12-13

    This paper presents an ultra-low power CMOS voltage reference circuit which is robust under biomedical extreme conditions, such as high temperature and high total ionized dose (TID) radiation. To achieve such performances, the voltage reference is designed in a suitable 130 nm Silicon-on-Insulator (SOI) industrial technology and is optimized to work in the subthreshold regime of the transistors. The design simulations have been performed over the temperature range of -40-200 °C and for different process corners. Robustness to radiation was simulated using custom model parameters including TID effects, such as mobilities and threshold voltages degradation. The proposed circuit has been tested up to high total radiation dose, i.e., 1 Mrad (Si) performed at three different temperatures (room temperature, 100 °C and 200 °C). The maximum drift of the reference voltage V(REF) depends on the considered temperature and on radiation dose; however, it remains lower than 10% of the mean value of 1.5 V. The typical power dissipation at 2.5 V supply voltage is about 20 μW at room temperature and only 75 μW at a high temperature of 200 °C. To understand the effects caused by the combination of high total ionizing dose and temperature on such voltage reference, the threshold voltages of the used SOI MOSFETs were extracted under different conditions. The evolution of V(REF) and power consumption with temperature and radiation dose can then be explained in terms of the different balance between fixed oxide charge and interface states build-up. The total occupied area including pad-ring is less than 0.09 mm2.

  14. Ultra-Low Power High Temperature and Radiation Hard Complementary Metal-Oxide-Semiconductor (CMOS Silicon-on-Insulator (SOI Voltage Reference

    Directory of Open Access Journals (Sweden)

    El Hafed Boufouss

    2013-12-01

    Full Text Available This paper presents an ultra-low power CMOS voltage reference circuit which is robust under biomedical extreme conditions, such as high temperature and high total ionized dose (TID radiation. To achieve such performances, the voltage reference is designed in a suitable 130 nm Silicon-on-Insulator (SOI industrial technology and is optimized to work in the subthreshold regime of the transistors. The design simulations have been performed over the temperature range of -40–200 °C and for different process corners. Robustness to radiation was simulated using custom model parameters including TID effects, such as mobilities and threshold voltages degradation. The proposed circuit has been tested up to high total radiation dose, i.e., 1 Mrad (Si performed at three different temperatures (room temperature, 100 °C and 200 °C. The maximum drift of the reference voltage VREF depends on the considered temperature and on radiation dose; however, it remains lower than 10% of the mean value of 1.5 V. The typical power dissipation at 2.5 V supply voltage is about 20 μW at room temperature and only 75 μ W at a high temperature of 200 °C. To understand the effects caused by the combination of high total ionizing dose and temperature on such voltage reference, the threshold voltages of the used SOI MOSFETs were extracted under different conditions. The evolution of VREF and power consumption with temperature and radiation dose can then be explained in terms of the different balance between fixed oxide charge and interface states build-up. The total occupied area including pad-ring is less than 0.09 mm2.

  15. High concentration effects of neutral-potential-well interface traps on recombination dc current-voltage lineshape in metal-oxide-silicon transistors

    Science.gov (United States)

    Chen, Zuhui; Jie, Bin B.; Sah, Chih-Tang

    2008-11-01

    Steady-state Shockley-Read-Hall kinetics is employed to explore the high concentration effect of neutral-potential-well interface traps on the electron-hole recombination direct-current current-voltage (R-DCIV) properties in metal-oxide-silicon field-effect transistors. Extensive calculations include device parameter variations in neutral-trapping-potential-well electron interface-trap density NET (charge states 0 and -1), dopant impurity concentration PIM, oxide thickness Xox, forward source/drain junction bias VPN, and transistor temperature T. It shows significant distortion of the R-DCIV lineshape by the high concentrations of the interface traps. The result suggests that the lineshape distortion observed in past experiments, previously attributed to spatial variation in surface impurity concentration and energy distribution of interface traps in the silicon energy gap, can also arise from interface-trap concentration along surface channel region.

  16. Zero-Voltage Switching PWM Strategy Based Capacitor Current-Balancing Control for Half-Bridge Three-Level DC/DC Converter

    DEFF Research Database (Denmark)

    Liu, Dong; Deng, Fujin; Zhang, Qi

    2017-01-01

    The current imbalance among the two input capacitors is one of the important issues of the half-bridge threelevel (HBTL) DC/DC converter, which would affect system performance and reliability. In this paper, a zero-voltage switching (ZVS) pulse-wide modulation (PWM) strategy including two operation...... modes is proposed. Based on the proposed ZVS PWM strategy, a capacitor current-balancing control is proposed for the HBTL DC/DC converter, where the currents on the two input capacitors can be kept balanced by alternating the two operation modes of the proposed ZVS PWM strategy. Therefore, the proposed...... control strategy can improve the performance and reliability of the converter in the aspect of balancing the thermal stresses and lifetimes among the two input capacitors. Finally, simulation and experimental studies are conducted and results verify the proposed control strategy....

  17. A Cell-to-Cell Battery Equalizer With Zero-Current Switching and Zero-Voltage Gap Based on Quasi-Resonant LC Converter and Boost Converter

    DEFF Research Database (Denmark)

    Shang, Yunlong; Zhang, Chenghui; Cui, Naxin

    2015-01-01

    voltage gap for large balancing current and ZVG between cells. Instead of a dedicated equalizer for each cell, only one balancing converter is employed and shared by all cells, reducing the size and implementation cost. Moreover, the equalization current can be regulated as needed by controlling the duty...... cycle of the BDDC, which not only prevents efficiently over-equalization but also abridges the balancing time. Simulation and experimental results show the proposed scheme exhibits outstanding balancing performance, and the energy conversion efficiency is higher than 98%. The validity of the proposed...... these difficulties, an innovative direct cell-to-cell battery equalizer based on quasi-resonant LC converter (QRLCC) and boost DC-DC converter (BDDC) is proposed. The QRLCC is employed to gain zero-current switching (ZCS), leading to a reduction of power losses. The BDDC is employed to enhance the equalization...

  18. Optical switching of a graphene mechanical switch using the Casimir effect

    Science.gov (United States)

    Inui, Norio

    2017-09-01

    We propose a method to control a graphene-based mechanical switch with light. By positioning a self-supporting graphene sheet parallel to a doped silicon membrane, irradiation of the membrane with light can bring the graphene into contact with the membrane. This operation is based on the enhancement of the Casimir force between the graphene sheet and a doped silicon membrane that results from photoionization; therefore, pull-in phenomena can occur even without applying any voltage. We theoretically investigated the dependence of the maximum displacement of a graphene sheet on the power of the irradiation light. Furthermore, the switching time is estimated by analyzing the time-evolution of the carrier density in a doped silicon membrane.

  19. 晶闸管开关电路在低压电器电寿命试验中的应用与分析%Application and Analysis of Thyristor Switch in Electrical Endurance Test of Low Voltage Electrical Apparatus

    Institute of Scientific and Technical Information of China (English)

    杨祥; 蒋凡; 马琳

    2014-01-01

    The non-contact thyristor circuit was specified for nonphysical breaking of big test current.In this case it not only has the function of a common mechanical switch as accompanied test samplem(ATS)but also helps to save hardware investment and human maintenance costs,and increases the test efficiency.The SCR thyristor circuit,based on the modification of existing motor-controlled softstarter,was used as silicon-control component. During the period of thyristor circuit modification,the voltage conversion peak and current multi-“zero-crossing”phenomena occurr because of SCR circuit conversion.The root reasons of these phenomena were analyzed and a software design of filtering waveform was specified to optimize the waveform,with which the actual problem is solved.Finally,with the multi-tests comparison between different calculation method,the practicability of the ATS circuit modification and correctness of software filtering method were validated.%采用晶闸管开关电路对较大过程试验电流进行无触点式非物理分断,替代机械开关实现了试验电路中陪试品的功能,极大地降低了产品试验站的硬件投入和人力维护成本,提高了测试效率。分析采用软件滤波的方式实现了波形的优化处理,解决了实际中的问题。最后通过试验,验证了该改造陪试电路的可行性和相应软件滤波方法的正确性。

  20. Increased voltage photovoltaic cell

    Science.gov (United States)

    Ross, B.; Bickler, D. B.; Gallagher, B. D. (Inventor)

    1985-01-01

    A photovoltaic cell, such as a solar cell, is provided which has a higher output voltage than prior cells. The improved cell includes a substrate of doped silicon, a first layer of silicon disposed on the substrate and having opposite doping, and a second layer of silicon carbide disposed on the first layer. The silicon carbide preferably has the same type of doping as the first layer.

  1. Dual-Input Soft-Switched DC-DC Converter with Isolated Current-Fed Half-Bridge and Voltage-Fed Full-Bridge for Fuel Cell or Photovoltaic Systems

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2013-01-01

    This paper introduces a new zero-voltage-switching (ZVS) isolated DC-DC converter with two input ports which can be utilized in hybrid energy systems, for instance, in a fuel cell and super-capacitor system. By fully using two high frequency transformers, the proposed converter can effectively...

  2. Porous silicon-VO{sub 2} based hybrids as possible optical temperature sensor: Wavelength-dependent optical switching from visible to near-infrared range

    Energy Technology Data Exchange (ETDEWEB)

    Antunez, E. E.; Salazar-Kuri, U.; Estevez, J. O.; Basurto, M. A.; Agarwal, V., E-mail: vagarwal@uaem.mx [Centro de Investigación en Ingeniería y Ciencias Aplicadas, Instituto de Investigación en Ciencias Básicas y Aplicadas, UAEM, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Mor. 62209 (Mexico); Campos, J. [Instituto de Energías Renovables, UNAM, Priv. Xochicalco S/N, Temixco, Mor. 62580 (Mexico); Jiménez Sandoval, S. [Laboratorio de Investigación en Materiales, Centro de Investigación y estudios Avanzados del Instituto Politécnico Nacional, Unidad Querétaro, Qro. 76001 (Mexico)

    2015-10-07

    Morphological properties of thermochromic VO{sub 2}—porous silicon based hybrids reveal the growth of well-crystalized nanometer-scale features of VO{sub 2} as compared with typical submicron granular structure obtained in thin films deposited on flat substrates. Structural characterization performed as a function of temperature via grazing incidence X-ray diffraction and micro-Raman demonstrate reversible semiconductor-metal transition of the hybrid, changing from a low-temperature monoclinic VO{sub 2}(M) to a high-temperature tetragonal rutile VO{sub 2}(R) crystalline structure, coupled with a decrease in phase transition temperature. Effective optical response studied in terms of red/blue shift of the reflectance spectra results in a wavelength-dependent optical switching with temperature. As compared to VO{sub 2} film over crystalline silicon substrate, the hybrid structure is found to demonstrate up to 3-fold increase in the change of reflectivity with temperature, an enlarged hysteresis loop and a wider operational window for its potential application as an optical temperature sensor. Such silicon based hybrids represent an exciting class of functional materials to display thermally triggered optical switching culminated by the characteristics of each of the constituent blocks as well as device compatibility with standard integrated circuit technology.

  3. Wide Bandgap Extrinsic Photoconductive Switches

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, James S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-07-03

    Semi-insulating Gallium Nitride, 4H and 6H Silicon Carbide are attractive materials for compact, high voltage, extrinsic, photoconductive switches due to their wide bandgap, high dark resistance, high critical electric field strength and high electron saturation velocity. These wide bandgap semiconductors are made semi-insulating by the addition of vanadium (4H and 6HSiC) and iron (2H-GaN) impurities that form deep acceptors. These deep acceptors trap electrons donated from shallow donor impurities. The electrons can be optically excited from these deep acceptor levels into the conduction band to transition the wide bandgap semiconductor materials from a semi-insulating to a conducting state. Extrinsic photoconductive switches with opposing electrodes have been constructed using vanadium compensated 6H-SiC and iron compensated 2H-GaN. These extrinsic photoconductive switches were tested at high voltage and high power to determine if they could be successfully used as the closing switch in compact medical accelerators.

  4. The low threshold voltage n-type silicon transistors based on a polymer/silica nanocomposite gate dielectric: The effect of annealing temperatures on their operation

    Science.gov (United States)

    Hashemi, Adeleh; Bahari, Ali; Ghasemi, Shahram

    2017-09-01

    In this work, povidone/silica nanocomposite dielectric layers were deposited on the n-type Si (100) substrates for application in n-type silicon field-effect transistors (FET). Thermogravimetric analysis (TGA) indicated that strong chemical interactions between polymer and silica nanoparticles were created. In order to examine the effect of annealing temperatures on chemical interactions and nanostructure properties, annealing process was done at 423-513 K. Atomic force microscopy (AFM) images show the very smooth surfaces with very low surface roughness (0.038-0.088 nm). The Si2p and C1s core level photoemission spectra were deconvoluted to the chemical environments of Si and C atoms respectively. The obtained results of deconvoluted X-ray photoelectron spectroscopy (XPS) spectra revealed a high percentage of silanol hydrogen bonds in the sample which was not annealed. These bonds were inversed to stronger covalence bonds (siloxan bonds) at annealing temperature of 423 K. By further addition of temperature, siloxan bonds were shifted to lower binding energy of about 1 eV and their intensity were abated at annealing temperature of 513 K. The electrical characteristics were extracted from current-Voltage (I-V) and capacitance-voltage (C-V) measurements in metal-insulator-semiconductor (MIS) structure. The all n-type Si transistors showed very low threshold voltages (-0.24 to 1 V). The formation of the strongest cross-linking at nanostructure of dielectric film annealed at 423 K caused resulted in an un-trapped path for the transport of charge carriers yielding the lowest threshold voltage (0.08 V) and the highest electron mobility (45.01 cm2/V s) for its FET. By increasing the annealing temperature (473 and 513 K) on the nanocomposite dielectric films, the values of the average surface roughness, the capacitance and the FET threshold voltage increased and the value of FET electron field-effect mobility decreased.

  5. Suppression Effect and Mechanism of Platinum and Nitrogen-Containing Silane on the Tracking and Erosion of Silicone Rubber for High-Voltage Insulation.

    Science.gov (United States)

    Chen, Wan Juan; Zeng, Xingrong; Lai, Xuejun; Li, Hongqiang; Fang, Wei Zhen; Hou, Fei

    2016-08-17

    How to effectively improve the tracking and erosion resistance of silicone rubber (SR) was an urgent topic in the field of high-voltage insulation. In this work, the tracking and erosion resistance of SR was significantly improved by incorporating platinum (Pt) catalyst and nitrogen-containing silane (NS). The suppression effect and mechanism of Pt/NS on tracking and erosion were studied by inclined plane (IP) test, thermogravimetry (TG), thermogravimetry-Fourier transform infrared spectrometry, laser Raman spectroscopy, and scanning electron microscopy. It revealed that when 1.4 phr of NS and 6.7 ppm of Pt were added, the tracking resistance of SR was improved from 2.5 to 4.5 kV level in the IP test, and the eroded mass was significantly reduced. This might be attributed to the synergistic effect of Pt/NS on silicone chains. At a high temperature produced by arc discharge, Pt/NS would catalyze radical cross-linking, meanwhile suppressing oxidation and depolymerization of silicone chains. Hence, a tightly cross-linked network was formed and protected inner materials from arc ablation. Moreover, carbon deposit during pyrolysis was suppressed by Pt/NS, which served as the secondary mechanism of tracking suppression.

  6. A Novel High-voltage Reactive Power Compensation Method Based on Magnetic-controlled Switch%基于磁控开关的高压无功补偿新方法

    Institute of Scientific and Technical Information of China (English)

    陶昆; 陈乔夫; 周理兵; 黄江; 王宁来; 刘健犇

    2013-01-01

    目前,在10~35 kV电压等级下对光伏发电、风力发电等无功需求变化范围大的负荷尚未有满意的动态无功补偿方案。当前常见的解决方案是高压晶闸管串联投切电容(thyristor switched capacitors,TSC)、晶闸管相控电抗%Currently, under the voltage grade from 10 kV to 35 kV, there’s no satisfactory solution to the problem of dynamic reactive power compensation for load whose need for reactive power varies in a large range. The common solutions are high-voltage thyristor switched capacitors (HVTSC), thyristor controlled reactor (TCR), magnetic-valve controllable reactor (MCR), and static synchronous compensator (STATCOM). However, both HVTSC and TCR use many thyristor valves connected in series, which requires not only a highly qualified trigger system but also a large amount of thyristors that leads to huge cost. Meanwhile, MCR inevitably generates harmonics and consumes considerable power when the load is light. STATCOM consists of many cascaded inverter blocks under high voltage condition, resulting in the decrease of reliability and increase of cost. Therefore, a novel high voltage reactive power compensation method based on magnetic-controlled switch (MCS) is proposed in this paper. Triacs are connected in parallel with the secondary winding of a transformer as switching components, and in this way the impedance of the transformer at primary side exhibits either a small leakage reactance or a large excitation reactance, during which the transformer behaves like a contactless switch to implement the dynamic switch of compensation capacitors. Simulation and experiments have verified the advantages such as small transient inrush, rapid response speed, low loss, and high reliability.

  7. A proposal for digital electro-optic switches with free-carrier dispersion effect and Goos-Hanchen shift in silicon-on-insulator waveguide corner mirror

    Science.gov (United States)

    Sun, DeGui

    2013-09-01

    In a silicon-on-insulator (SOI) waveguide corner mirror (WCM) structure, with the quantum process of a frustrated total internal reflection (FTIR) phenomenon and the time delay principle in the two-dimensional potential barrier tunneling process of a mass of particles, we derive an accurate physical model for the Goos-Hanchen (GH) shift of optical guided-mode in the FTIR process, and in principle match the GH shift jumping states with the independent guided-modes. Then, we propose and demonstrate a new regime of 1 × N digital optical switches with a matching state between the free-carrier dispersion (FCD) based refractive index modulation (RIM) of silicon to create a GH shift jumping function of a photonic signal at the reflecting interface and the independent guided-modes in the FTIR process, where a MOS-capacitor type electro-optic modulation regime is proposed and discussed to realize an effective FCD-based RIM. At the critical matching state, i.e., the incident of an optical beam is at the vicinity of Brewster angle in the WCM, a mini-change of refractive index of waveguide material can cause a great jump of GH shift along the FTIR reflecting interface, and further a 1 × N digital optical switching process could be realized. For a 350-500 nm single-mode rib waveguide made on the 220 nm CMOS-compatible SOI substrate and with the FCD effect based RIM of silicon crystal, a concentration variation of 1018-1019 cm-3 has caused a 0.5-2.5 μm GH shift of reflected beam, which is at 2-5 times of a mode-size and hence radically convinces an optical switching function with a 1 × 3-1 × 10 scale.

  8. Automatic voltage imbalance detector

    Science.gov (United States)

    Bobbett, Ronald E.; McCormick, J. Byron; Kerwin, William J.

    1984-01-01

    A device for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

  9. SSP Technology Investigation of a High-Voltage DC-DC Converter

    Science.gov (United States)

    Pappas, J. A.; Grady, W. M.; George, Patrick J. (Technical Monitor)

    2002-01-01

    The goal of this project was to establish the feasibility of a high-voltage DC-DC converter based on a rod-array triggered vacuum switch (RATVS) for the Space Solar Power system. The RATVS has many advantages over silicon and silicon-carbide devices. The RATVS is attractive for this application because it is a high-voltage device that has already been demonstrated at currents in excess of the requirement for an SSP device and at much higher per-device voltages than existing or near-term solid state switching devices. The RATVS packs a much higher specific power rating than any solid-state device and it is likely to be more tolerant of its surroundings in space. In addition, pursuit of an RATVS-based system would provide NASA with a nearer-term and less expensive power converter option for the SSP.

  10. Open-circuit voltage analysis of p-i-n type amorphous silicon solar cells deposited at low temperature

    Institute of Scientific and Technical Information of China (English)

    Ni Jian; Zhang Jian-Jun; Cao Yu; Wang Xian-Bao; Li Chao; Chen Xin-Liang; Geng Xin-Hua; Zhao Ying

    2011-01-01

    This paper identifies the contributions of p-a-SiC:H layers and i-a-Si:H layers to the open circuit voltage of p-i-n type a-Si:H solar cells deposited at a low temperature of 125 ℃.We find that poor quality p-a-SiC:H films under regular conditions lead to a restriction of open circuit voltage although the band gap of the i-layer varies widely.A significant improvement in open circuit voltage has been obtained by using high quality p-a-SiC:H films optimized at the "low-power regime" under low silane flow rates and high hydrogen dilution conditions.

  11. A non-contact mechanical solution for implementing synchronized switching techniques for energy harvesting using reed switches

    Science.gov (United States)

    Shih, Ya Shan; Vasic, Dejan; Jong Wu, Wen

    2016-12-01

    In this work we proposed a new mechanical method of implementing the synchronized switching technique for piezoelectric energy harvesting based on reed switches. Serving as a mechanical displacement monitor and the switch itself, it holds the merit of non-contact, persistence, and the low voltage threshold of merely a single PN junction. However, as all mechanical switches inherits chattering, or bouncing, energy loss and damping on the inversion was caused. To side pass the chattering, three types of electro-mechanical hybrid switches were furthermore developed to stabilize the interfered current flow: resistor-capacitor snubbers, inductor-capacitor snubbers, and silicon controlled rectifiers (SCRs). Each of the method has its merit and suitable working conditions. Comparing to conventional electrical switches, the proposed switches, greatly reduced the switch impedance since the mechanical switch part provides a physically open switch, and the electrical switch part merely consist of either a diode and a MOSFET pair, or a single SCR. Subsequently, the power loss due to the circuit was efficiently eliminated.

  12. Dynamic Simulation Investigation of 750kV Stepped Switching Controllable High Voltage Shunt Reactor%750kV分级投切式可控高压并联电抗器的动态模拟研究

    Institute of Scientific and Technical Information of China (English)

    秦睿; 郭文科; 王惠中

    2012-01-01

    This paper describes the stepped switching controllable high voltage shunt reactors basic principle, the device can regulate the system reactive power, voltage and frequency over inhibition of arc current, with a continuous smooth power adjustable, harmonic current is small and the advantages of fast response. It analyzes the stepped switching controllable high voltage shunt reactor protection features and functionality, protection and circuit breaker protection, mainly to explain the valve protection and circuit breaker protection. According to the stepped switching controllable high voltage shunt reactors principles and technical characteristics, combined with power system dynamic simulation laboratory simulation system characteristics, stepped switching controllable high voltage shunt reactor protection system dynamic simulation experimental research, besides valve and circuit breaker protection dynamic simulation test results are necessary analysis and research.%主要分析了分级投切式可控高压并联电抗器保护的特点和功能,对阀保护和断路器保护进行了说明,并对阀保护和断路器保护动态模拟试验结果进行了必要的分析和研究.根据分级投切式可控高压并联电抗器的原理和技术特点,结合试验室电力系统动态模拟仿真系统的特点,对分级投切式可控高压并联电抗器的保护系统进行了动态模拟试验研究.

  13. An anti-ferroelectric gated Landau transistor to achieve sub-60 mV/dec switching at low voltage and high speed

    Science.gov (United States)

    Karda, Kamal; Jain, Ankit; Mouli, Chandra; Alam, Muhammad Ashraful

    2015-04-01

    Landau field effect transistors promise to lower the power-dissipation of integrated circuits (ICs) by reducing the subthreshold swing (S) below the Boltzmann limit of 60 mV/dec. The key idea is to replace the classical gate insulator with dielectrics that exhibit negative capacitance (NC) associated with double-well energy landscape, for example, ferroelectrics (FE), air-gap capacitors, or a combination thereof. Indeed, S is dramatically reduced, constrained only by the limits of hysteresis-free operation. Unfortunately, the following limitations apply (i) the need for capacitance matching constrains steep S only to the small subthreshold region for FE based negative capacitance field effect transistor (NCFET) and requires an insulator too thick for sub-20 nm scaling; (ii) the kinetics of mechanical switching for airgap based NCFET obviate high-speed operation; and (iii) the lattice mismatch between the substrate and the dielectric makes defect-free integration difficult. In this article, we demonstrate that a FET integrated with 10 nm HfO2-based anti-ferroelectric and FE hetero stack would achieve ultralow S with ON-current ( Io n) at par with classical transistors at significantly lower voltage and would simplify integration. Our results address the well-known challenges/criticisms of classical Landau transistors, thereby, making them technology relevant for modern ICs.

  14. Design of Compact High-voltage Switching Mode-power Supply%小型高压开关电源设计

    Institute of Scientific and Technical Information of China (English)

    马跃; 邓玉福; 于桂英

    2011-01-01

    High voltage power is extensively used in scientific and industrial applications. As one indispensable component,custom designed high voltage power supply can be found in instruments for spectroscopy, medicine, mass spectrometry,eleetrostatic spraying, lasers, spectrometers, X-ray diffraction, and many other analytical imaging and process applications.Traditional high-voltnge power supply mainly adopts of linear technology, which is low conversion efficiency, large volume,heavy, and inconvenient of operation and maintenance. With the development and advantage of power supply technology, the requirements of intelligent level, conversion efficiency and load capacity are becoming stronger. This paper describes a high voltage switching power supply that based on SCM and PMW technology. This kind of power supply adopts single ended type promote and controlled by STC89C51 SCM and TL494. By means of combining diodes and capacitors, the circuit converts AC electric power delivered by the transformer to higher DC voltage with the act of rectifying and smoothing. The power adopts digital regulation and closed loop real-time monitoring to cooperate with an analog drcuit. The advantages of the power supply are obvious, such as strong generality, wide output range, high stable voltage accuracy, excellent control property, etc.%高压直流电源在科学和工业生产中有着广泛的应用,是光学仪器,医疗设备,质谱分析,静电喷涂,激光器,X射线衍射仪以及其他一些分析成像射线类仪器中不可缺少的重要部件.传统的高压电源多采用线性技术,这种结构形式造成电源变换效率低,体积大,重量沉,操作维修不方便.随着电源技术的发展,人们对高压电源的智能化程度、转换效率和带负载能力提出了更高的要求.设计了一种以单片机和脉宽调制(PMW)技术为基础的智能化小型高压电源.该电源由STC89C51单片机和脉宽调制芯片TL494控制,采用单端式开关电

  15. Fault identification in crystalline silicon PV modules by complementary analysis of the light and dark current-voltage characteristics

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Sera, Dezso; Hacke, Peter

    2014-01-01

    Photovoltaic system (PV) maintenance and diagnostic tools are often based on performance models of the system, complemented with light current-voltage (I-V) measurements, visual inspection and/or thermal imaging. Although these are invaluable tools in diagnosing PV system performance losses and f...

  16. Temperature-Independent Switching Rates for a Random Telegraph Signal in a Silicon Metal-Oxide-Semiconductor Field-Effect Transistor at Low Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Borland, Nick; Fleetwood, D.M.; Scofield, John H.

    1999-07-19

    We have observed discrete random telegraph signals (RTS'S) in the drain voltages of three, observed above 30 K were thermally activated. The switching rate for the only RTS observed below 30 K was thermally activated above 30 K but temperature-independent below 10 K. To our knowledge, this cross-over from thermal activation to tunneling behavior has not been previously observed for RTS's Metal-oxide-semiconductor field-effect transistors (MCEWETS) often exhibit relatively large levels of low-frequency (1/fl noise) [1,2]. Much evidence suggests that this noise is related to the capture all cases, switching rates have been thermally activated, often with different activation energies for capture and/or emission is accompanied by lattice relaxation. Though thermally activated behavior has sufficiently low temperatures [7,9]. While not observed in MOSFETS, cross-over from thermal activation to configurational tunneling has been observed for RTS's in junctions [13]. drain voltage was observed to randomly switch between two discrete levels, designated as Vup and Vdn, similar to RTS's reported by others [2,7'- 11 ]. We have characterized six RTS `S for temperatures above 30 K where thermally activated switching rates are observed. The properties of five of these have been the trap, i.e., the mean time a captured charge carrier spends in the trap before it is emitted. Similarly, we identify the mean time in the low resistance state ( trup in state Vup) as the capture time rc. F@ure 1 shows a typical time trace of the drain-voltage fluctuation &d(t)= Vd(t)+Vd>. This indicate that both the mean capture and emission times become independent of Tat low temperatures and where a= capture or emission, is temperature independent. The solid curve in Figure 3(a) (mean capture time) was obtained using a weighted nonlinear charge carriers are not in thermal equilibrium with the lattice, i.e., that while the lattice is being cooled Instead, we believe that the

  17. Low driving voltage Mach-Zehnder interference modulator constructed from an electro-optic polymer on ultra-thin silicon with a broadband operation.

    Science.gov (United States)

    Sato, Hiromu; Miura, Hiroki; Qiu, Feng; Spring, Andrew M; Kashino, Tsubasa; Kikuchi, Takamasa; Ozawa, Masaaki; Nawata, Hideyuki; Odoi, Keisuke; Yokoyama, Shiyoshi

    2017-01-23

    An electro-optic (EO) polymer waveguide using an ultra-thin silicon hybrid has been designed and fabricated. The silicon core has the thickness of 50 nm and a width of 5 μm. The waveguide was completed after covering the cladding with the high temperature stable EO polymer. We have demonstrated a low half-wavelength voltage of 0.9 V at the wavelength of 1.55 μm by using a Mach-Zehnder interference modulator with TM mode operation. The measured modulation corresponded to an effective in-device EO coefficient of 165 pm/V. By utilizing the traveling-wave electrode on the modulator the high-frequency response was tested up to 40 GHz. The 3 dB modulation bandwidth was measured to be 23 GHz. In addition, the high frequency sideband spectral measurement revealed that a linear response of the modulation index against the RF power was confirmed up to 40 GHz signal.

  18. Test bench for thermal cycling of 10 kV silicon carbide power modules

    DEFF Research Database (Denmark)

    Sønderskov, Simon Dyhr; Jørgensen, Asger Bjørn; Maarbjerg, Anders Eggert;

    2016-01-01

    This paper presents a test bench for lifetime investigation of 10 kV silicon carbide power modules. The test bench subjects high voltage switching operation to the modules while power cycling. Thus both a thermal and electrical operating point is emulated. The power cycling setup features offline...

  19. Nanoporous silicon oxide memory.

    Science.gov (United States)

    Wang, Gunuk; Yang, Yang; Lee, Jae-Hwang; Abramova, Vera; Fei, Huilong; Ruan, Gedeng; Thomas, Edwin L; Tour, James M

    2014-08-13

    Oxide-based two-terminal resistive random access memory (RRAM) is considered one of the most promising candidates for next-generation nonvolatile memory. We introduce here a new RRAM memory structure employing a nanoporous (NP) silicon oxide (SiOx) material which enables unipolar switching through its internal vertical nanogap. Through the control of the stochastic filament formation at low voltage, the NP SiOx memory exhibited an extremely low electroforming voltage (∼ 1.6 V) and outstanding performance metrics. These include multibit storage ability (up to 9-bits), a high ON-OFF ratio (up to 10(7) A), a long high-temperature lifetime (≥ 10(4) s at 100 °C), excellent cycling endurance (≥ 10(5)), sub-50 ns switching speeds, and low power consumption (∼ 6 × 10(-5) W/bit). Also provided is the room temperature processability for versatile fabrication without any compliance current being needed during electroforming or switching operations. Taken together, these metrics in NP SiOx RRAM provide a route toward easily accessed nonvolatile memory applications.

  20. Studies on temperature dependence of current-voltage characteristics of glancing angle deposited indium oxide nanowire on silicon substrate

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, Aniruddha, E-mail: aniruddhamo@gmail.com; Das, Amit Kumar [Department of Physics, National Institute of technology Durgapur, Mahatma Gandhi Rd, A-Zone, Durgapur, West Bengal, India-713209 (India); Dey, Anubhab [Indian Institute of Science Education and Research, Thiruvananthapuram, Computer Science Building, College of Engineering Trivandrum Campus, Thiruvananthapuram, Kerala 695016 (India); Choudhuri, Bijit [Department of Electronics & Communication Engineering, National Institute of Technology Agartala, Jirania, Tripura, India - 799046 (India)

    2016-05-06

    The 1D perpendicular In{sub 2-x}O{sub 3-y} nanostructure arrays have been synthesized by using glancing angle deposition (GLAD) technique. A low deposition rate of 0.5 A°/S produced highly porous structure. The current - voltage characteristics for the In{sub 2-x}O{sub 3-y}nanocolumnar array based were measured through a gold Schottky contact at different temperatures. The temperature dependent ideality factor was calculated from the observed current – voltage characteristics. The ideality factor was found to vary from 4.19 to 2.75 with a variation in temperature from 313 K to 473 K.

  1. Substrate bias voltage and deposition temperature dependence on properties of rf-magnetron sputtered titanium films on silicon (100)

    Indian Academy of Sciences (India)

    B Geetha Priyadarshini; Shampa Aich; Madhusudan Chakraborty

    2014-12-01

    Thin films or a coating of any sort prior to its application into real world has to be studied for the dependence of process variables on their structural and functional properties. One such study based on the influence of substrate conditions viz. substrate-bias voltage and substrate temperature on the structural and morphological properties, could be of great interest as far as Ti thin films are concerned. From X-ray texture pole figure and electron microscopy analysis, it was found that substrate bias voltage strongly influence preferential orientation and morphology of Ti films grown on Si (100) substrate. Deposition at higher substrate temperature causes the film to react with Si forming silicides at the film/Si substrate interface. Ti film undergoes a microstructural transition from hexagonal plate-like to round-shaped grains as the substrate temperature was raised from 300 to 50 °C during film deposition.

  2. Device for monitoring cell voltage

    Science.gov (United States)

    Doepke, Matthias [Garbsen, DE; Eisermann, Henning [Edermissen, DE

    2012-08-21

    A device for monitoring a rechargeable battery having a number of electrically connected cells includes at least one current interruption switch for interrupting current flowing through at least one associated cell and a plurality of monitoring units for detecting cell voltage. Each monitoring unit is associated with a single cell and includes a reference voltage unit for producing a defined reference threshold voltage and a voltage comparison unit for comparing the reference threshold voltage with a partial cell voltage of the associated cell. The reference voltage unit is electrically supplied from the cell voltage of the associated cell. The voltage comparison unit is coupled to the at least one current interruption switch for interrupting the current of at least the current flowing through the associated cell, with a defined minimum difference between the reference threshold voltage and the partial cell voltage.

  3. Silicon Carbide Diodes Performance Characterization and Comparison With Silicon Devices

    Science.gov (United States)

    Lebron-Velilla, Ramon C.; Schwarze, Gene E.; Trapp, Scott

    2003-01-01

    Commercially available silicon carbide (SiC) Schottky diodes from different manufacturers were electrically tested and characterized at room temperature. Performed electrical tests include steady state forward and reverse I-V curves, as well as switching transient tests performed with the diodes operating in a hard switch dc-to-dc buck converter. The same tests were performed in current state of the art silicon (Si) and gallium arsenide (GaAs) Schottky and pn junction devices for evaluation and comparison purposes. The SiC devices tested have a voltage rating of 200, 300, and 600 V. The comparison parameters are forward voltage drop at rated current, reverse current at rated voltage and peak reverse recovery currents in the dc to dc converter. Test results show that steady state characteristics of the tested SiC devices are not superior to the best available Si Schottky and ultra fast pn junction devices. Transient tests reveal that the tested SiC Schottky devices exhibit superior transient behavior. This is more evident at the 300 and 600 V rating where SiC Schottky devices showed drastically lower reverse recovery currents than Si ultra fast pn diodes of similar rating.

  4. Manufacture of Radio Frequency Micromachined Switches with Annealing

    Directory of Open Access Journals (Sweden)

    Cheng-Yang Lin

    2014-01-01

    Full Text Available The fabrication and characterization of a radio frequency (RF micromachined switch with annealing were presented. The structure of the RF switch consists of a membrane, coplanar waveguide (CPW lines, and eight springs. The RF switch is manufactured using the complementary metal oxide semiconductor (CMOS process. The switch requires a post-process to release the membrane and springs. The post-process uses a wet etching to remove the sacrificial silicon dioxide layer, and to obtain the suspended structures of the switch. In order to improve the residual stress of the switch, an annealing process is applied to the switch, and the membrane obtains an excellent flatness. The finite element method (FEM software CoventorWare is utilized to simulate the stress and displacement of the RF switch. Experimental results show that the RF switch has an insertion loss of 0.9 dB at 35 GHz and an isolation of 21 dB at 39 GHz. The actuation voltage of the switch is 14 V.

  5. Manufacture of radio frequency micromachined switches with annealing.

    Science.gov (United States)

    Lin, Cheng-Yang; Dai, Ching-Liang

    2014-01-17

    The fabrication and characterization of a radio frequency (RF) micromachined switch with annealing were presented. The structure of the RF switch consists of a membrane, coplanar waveguide (CPW) lines, and eight springs. The RF switch is manufactured using the complementary metal oxide semiconductor (CMOS) process. The switch requires a post-process to release the membrane and springs. The post-process uses a wet etching to remove the sacrificial silicon dioxide layer, and to obtain the suspended structures of the switch. In order to improve the residual stress of the switch, an annealing process is applied to the switch, and the membrane obtains an excellent flatness. The finite element method (FEM) software CoventorWare is utilized to simulate the stress and displacement of the RF switch. Experimental results show that the RF switch has an insertion loss of 0.9 dB at 35 GHz and an isolation of 21 dB at 39 GHz. The actuation voltage of the switch is 14 V.

  6. 光梯度力驱动的纳米硅基光开关∗%A nano-silicon-photonic switch driven by an optical gradient force

    Institute of Scientific and Technical Information of China (English)

    林建潇; 吴九汇; 刘爱群; 陈喆; 雷浩

    2015-01-01

    通过一道光改变另一道光的传输路线是光子集成网络中重要而长远的目标,然而,由于硅材料的光学非线性较弱,在硅材料上实现开关的全光控制难以实现.因此本文提出了一种由光梯度力驱动的纳米硅基光开关,实现了硅基光开关的全光控制.该光开关由一个部分悬空的微环谐振器和一个交叉波导结构构成,当通入一道控制光时,悬空的微环谐振器在光梯度力的作用下发生弯曲,微环谐振器的谐振波长随之发生变化,从而实现光信号的传输路线发生改变.该光开关利用纳米光子制造技术在标准绝缘体上硅晶圆上制造,实验数据得出其最小消光比为10.67 dB,最大串扰为−11.01 dB,开关时间分别为180 ns和170 ns.该光开关具有尺寸小,响应速度快,低损耗和可拓展等优点,在片上集成光路、高速信号处理以及下一代光纤通信网络中具有潜在应用.%Using light to dynamically and stably redirect the flow of another beam of light is a long-term goal for photonic-integrated circuits. However, it is challenging to realize a practically all-optical switching device in silicon owing to its weak optical nonlinearity. Major published work on all-optical switches were using single-photon absorption and two-photon absorption, which requires ultrahigh switching energy. This paper presents a nano-silicon-photonic all-optical switch driven by an optical gradient force, in which a fast switching speed with low power consumption is obtained. Each switching element is composed of a waveguide crossing connection and a micro-ring resonator. The ring resonator is side-coupled to a double-etched waveguide crossing, while the micro-ring resonator is partially released from the substrate and becomes free-standing. When the“drop”port is in“OFF”state, the wavelength of the signal light from the“input”port does not satisfy the resonant condition in the micro-ring. Therefore, light is

  7. 240 W全桥移相ZVS变换器的设计%Design of a 240 W full-bridge converter with phase shift control and zero voltage switching

    Institute of Scientific and Technical Information of China (English)

    张本庚; 刘平

    2011-01-01

    The phase-shifted full-bridge zero-voltage-switching (PS-FB-ZVS) PWM converter is widely used in medium and high power levels. However, there are two problems existing in this kind of converter; one is that lagging leg has narrow zero-voltage-switching ranges,and the other is that the output rectifier diodes suffer the parasitic oscillation and voltage spike resulted by the reverse recovery of the rectifier diodes. The converter discussed in the literalure one had wide zero-voltage-switching ranges of lagging leg switches by using the magnetizing current. In addition, the resonance between the leakage inductor of the transformer and the rectifier capacitors could reduce the current stresses of the rectifier diodes and coeduction losses. Based on the principle of the converter, one 240 W zero-voltage-switching (ZVS) soft-switching power supply on the phase shift control was designed The procedures of main circuit design were presented. The experimental waveforms were given in the end.%移相全桥零电压变换器在中大功率场合中得到了广泛的应用,但其滞后臂只能在较窄的负载范围内实现软开关,并且其输出整流二极管反向恢复时产生严重的寄生振荡,二极管上存在很高的尖峰压.而文献[1]中变换器的滞后臂利用励磁电感电流可以在较宽的负载范围内实现软开关.变压器的漏感与电容的谐振可以减小整流管的电流应力和导通损失.基于此变换器的工作原理,设计了一台240 W移相控制零电压软开关电源,给出了主电路的设计过程,最后给出了实验波形.

  8. A 1.5 ns OFF/ON switching-time voltage-mode LVDS driver/receiver pair for asynchronous AER bit-serial chip grid links with up to 40 times event-rate dependent power savings.

    Science.gov (United States)

    Zamarreno-Ramos, Carlos; Kulkarni, Raghavendra; Silva-Martinez, Jose; Serrano-Gotarredona, Teresa; Linares-Barranco, Bernabe

    2013-10-01

    This paper presents a low power fast ON/OFF switchable voltage mode implementation of a driver/receiver pair intended to be used in high speed bit-serial Low Voltage Differential Signaling (LVDS) Address Event Representation (AER) chip grids, where short (like 32-bit) sparse data packages are transmitted. Voltage-Mode drivers require intrinsically half the power of their Current-Mode counterparts and do not require Common-Mode Voltage Control. However, for fast ON/OFF switching a special high-speed voltage regulator is required which needs to be kept ON during data pauses, and hence its power consumption must be minimized, resulting in tight design constraints. A proof-of-concept chip test prototype has been designed and fabricated in low-cost standard 0.35 μ m CMOS. At ± 500 mV voltage swing with 500 Mbps serial bit rate and 32 bit events, current consumption scales from 15.9 mA (7.7 mA for the driver and 8.2 mA for the receiver) at 10 Mevent/s rate to 406 μ A ( 343 μ A for the driver and 62.5 μA for the receiver) for an event rate below 10 Kevent/s, therefore achieving a rate dependent power saving of up to 40 times, while keeping switching times at 1.5 ns. Maximum achievable event rate was 13.7 Meps at 638 Mbps serial bit rate. Additionally, differential voltage swing is tunable, thus allowing further power reductions.

  9. 基于MCU控制的开关电源稳压电路设计%Design for voltage regulator circuit of switching power supply based on MCU control

    Institute of Scientific and Technical Information of China (English)

    李淑红; 邢军

    2015-01-01

    A voltage regulator circuit of the switching power supply based on MCU control was designed,which is com-posed of rectification filtering circuit,push-pull power conversion circuit and control circuit. In this circuit,the output voltage of the switching power supply is controlled by regulating PWM via the MCU. The digital signal output by MCU is converted into analog signal through the DAC0832. The analog signal is taken as the reference voltage of the second pin of the switching con-trol chip SG3525. SG3525 generates PWM control pulse automatically according to the variation of reference voltage to regulate the output pulse width of the switching tube,so the purpose of regulating the output voltage is achieved. The experimental re-sults show that the output voltage adjustable range is 28~36 V,the maximum output current is 15 A,and the efficiency of the switching power supply is 89%.%设计了一款基于MCU控制的开关电源稳压电路,该系统主要由整流滤波电路、推挽式功率变换电路和控制电路组成,并通过MCU调节PWM控制开关电源输出电压.MCU输出的数字信号通过DAC0832转换为模拟信号,该模拟信号作为开关控制芯片SG3525第二管脚的基准电压,SG3525根据基准电压的变化自动产生PWM控制脉冲,调节开关管的输出脉宽,从而达到调节输出电压的目的.实验表明,输出电压可调范围为28~36 V,最大输出电流Imax=15 A,开关电源的效率为η=89%.

  10. Development of Amorphous/Microcrystalline Silicon Tandem Thin-Film Solar Modules with Low Output Voltage, High Energy Yield, Low Light-Induced Degradation, and High Damp-Heat Reliability

    Directory of Open Access Journals (Sweden)

    Chin-Yi Tsai

    2014-01-01

    Full Text Available In this work, tandem amorphous/microcrystalline silicon thin-film solar modules with low output voltage, high energy yield, low light-induced degradation, and high damp-heat reliability were successfully designed and developed. Several key technologies of passivation, transparent-conducting-oxide films, and cell and segment laser scribing were researched, developed, and introduced into the production line to enhance the performance of these low-voltage modules. A 900 kWp photovoltaic system with these low-voltage panels was installed and its performance ratio has been simulated and projected to be 92.1%, which is 20% more than the crystalline silicon and CdTe counterparts.

  11. A CMOS Switched Transconductor Mixer

    NARCIS (Netherlands)

    Klumperink, Eric A.M.; Louwsma, S.M.; Wienk, Gerhardus J.M.; Nauta, Bram

    A new CMOS active mixer topology can operate at low supply voltages by the use of switches exclusively connected to the supply voltages. Such switches require less voltage headroom and avoid gate-oxide reliability problems. Mixing is achieved by exploiting two transconductors with cross-coupled

  12. High-performance and power-efficient 2${\\times}$2 optical switch on Silicon-on-Insulator

    CERN Document Server

    Han, Zheng; Checoury, Xavier; Bourderionnet, Jérôme; Boucaud, Philippe; De Rossi, Alfredo; Combrié, Sylvain

    2015-01-01

    A compact (15{\\mu}m${\\times}${\\mu}m) and highly-optimized 2${\\times}$2 optical switch is demonstrated on a CMOS-compatible photonic crystal technology. On-chip insertion loss are below 1dB, static and dynamic contrast are 40dB and >20dB respectively. Owing to efficient thermo-optic design, the power consumption is below 3 mW while the switching time is 1 {\\mu}s.

  13. Gas-driven ultrafast reversible switching of super-hydrophobic adhesion on palladium-coated silicon nanowires.

    Science.gov (United States)

    Seo, Jungmok; Lee, Soonil; Han, Heetak; Jung, Hwae Bong; Hong, Juree; Song, Giyoung; Cho, Suk Man; Park, Cheolmin; Lee, Wooyoung; Lee, Taeyoon

    2013-08-14

    A gas-driven ultrafast adhesion switching of water droplets on palladium-coated Si nanowire arrays is demonstrated. By regulating the gas-ambient between the atmosphere and H2 , the super-hydrophobic adhesion is repeatedly switched between water-repellent and water-adhesive. The capability of modulating the super-hydrophobic adhesion on a super-hydrophobic surface with a non-contact mode could be applicable to novel functional lab-on-a-chip platforms.

  14. High Voltage Charge Pump

    KAUST Repository

    Emira, Ahmed A.

    2014-10-09

    Various embodiments of a high voltage charge pump are described. One embodiment is a charge pump circuit that comprises a plurality of switching stages each including a clock input, a clock input inverse, a clock output, and a clock output inverse. The circuit further comprises a plurality of pumping capacitors, wherein one or more pumping capacitors are coupled to a corresponding switching stage. The circuit also comprises a maximum selection circuit coupled to a last switching stage among the plurality of switching stages, the maximum selection circuit configured to filter noise on the output clock and the output clock inverse of the last switching stage, the maximum selection circuit further configured to generate a DC output voltage based on the output clock and the output clock inverse of the last switching stage.

  15. Study on Leakage Audio Detector for High Voltage Switch Cabinet Based on ZigBee Technology%基于ZigBee的高压开关柜漏电音频检测仪研究

    Institute of Scientific and Technical Information of China (English)

    朱品昌; 王芳; 袁秀平; 倪继锋; 茅红伟

    2011-01-01

    ZigBee wireless communication technology was introduced. The current automatic protection function of high voltage switch cabinet was analyzed. A design concept of high voltage switch cabinet's leakage audio detector was proposed based on ZigBee technology. The design of wireless communication module was completed which met the using requirements of substation. The design improves the security and reliability of leakage detection and protection system of substation high voltage switch cabinet, and it has a certain application prospect.%介绍了ZigBee无线通信技术,分析了现有变电站高压开关柜的自动保护功能,提出一种基于ZigBee技术的高压开关柜高压漏电音频检测仪设计构想,完成了适用于变电站使用要求的无线通信模块设计.该设计提高了变电站高压开关柜高压漏电检测与防护系统的安全性和可靠性,具有一定的应用前景.

  16. Impulse voltage control of continuously tunable bipolar resistive switching in Pt/Bi0.9Eu0.1FeO3/Nb-doped SrTiO3 heterostructures

    Science.gov (United States)

    Wei, Maocai; Liu, Meifeng; Wang, Xiuzhang; Li, Meiya; Zhu, Yongdan; Zhao, Meng; Zhang, Feng; Xie, Shuai; Hu, Zhongqiang; Liu, Jun-Ming

    2017-03-01

    Epitaxial Bi0.9Eu0.1FeO3 (BEFO) thin films are deposited on Nb-doped SrTiO3 (NSTO) substrates by pulsed laser deposition to fabricate the Pt/BEFO/NSTO (001) heterostructures. These heterostructures possess bipolar resistive switching, where the resistances versus writing voltage exhibits a distinct hysteresis loop and a memristive behavior with good retention and anti-fatigue characteristics. The local resistive switching is confirmed by the conductive atomic force microscopy (C-AFM), suggesting the possibility to scale down the memory cell size. The observed memristive behavior could be attributed to the ferroelectric polarization effect, which modulates the height of potential barrier and width of depletion region at the BEFO/NSTO interface. The continuously tunable resistive switching behavior could be useful to achieve non-volatile, high-density, multilevel random access memory with low energy consumption.

  17. Impulse voltage control of continuously tunable bipolar resistive switching in Pt/Bi{sub 0.9}Eu{sub 0.1}FeO{sub 3}/Nb-doped SrTiO{sub 3} heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Maocai; Liu, Meifeng; Wang, Xiuzhang [Hubei Normal University, Institute for Advanced Materials, and School of Physics and Electronic Science, Huangshi (China); Li, Meiya; Zhu, Yongdan; Zhao, Meng; Zhang, Feng; Xie, Shuai [Wuhan University, School of Physics and Technology, and Key Laboratory of Artificial Micro/Nano Structures of the Ministry of Education, Wuhan (China); Hu, Zhongqiang [Northeastern University, Department of Electrical and Computer Engineering, Boston, MA (United States); Liu, Jun-Ming [Nanjing University, Laboratory of Solid State Microstructures, Nanjing (China)

    2017-03-15

    Epitaxial Bi{sub 0.9}Eu{sub 0.1}FeO{sub 3} (BEFO) thin films are deposited on Nb-doped SrTiO{sub 3} (NSTO) substrates by pulsed laser deposition to fabricate the Pt/BEFO/NSTO (001) heterostructures. These heterostructures possess bipolar resistive switching, where the resistances versus writing voltage exhibits a distinct hysteresis loop and a memristive behavior with good retention and anti-fatigue characteristics. The local resistive switching is confirmed by the conductive atomic force microscopy (C-AFM), suggesting the possibility to scale down the memory cell size. The observed memristive behavior could be attributed to the ferroelectric polarization effect, which modulates the height of potential barrier and width of depletion region at the BEFO/NSTO interface. The continuously tunable resistive switching behavior could be useful to achieve non-volatile, high-density, multilevel random access memory with low energy consumption. (orig.)

  18. Line-to-line voltage based modulation scheme for single-phase reduced switch ac-dc-ac converters to achieve improved performance

    DEFF Research Database (Denmark)

    Qin, Zian; Loh, Poh Chiang; Blaabjerg, Frede

    2015-01-01

    . With the SVPWM or DPWM proposed in literatures, the generation of the references is phase voltage based. But the phase voltages actually cannot be controlled directly by the PWM converter, since they can be influenced by both of terminal voltages and the load network while the PWM converter can only control...

  19. Radiation Hard GaNFET High Voltage Multiplexing (HV Mux) for the ATLAS Upgrade Silicon Strip Tracker

    CERN Document Server

    Lynn, David; The ATLAS collaboration

    2017-01-01

    The outer radii of the inner tracker (ITk) for the Phase-II Upgrade of the ATLAS experiment will consist of groups of silicon strip sensors mounted on common support structures. Lack of space creates a need to remotely disable a failing sensor from the common HV bus. We have developed circuitry consisting of a GaNFET transistor and a HV Multiplier circuit to disable a failed sensor. We will present two variants of the HV Mux circuitry and show irradiation results on individual components with an emphasis on the GaNFET results. We will also discuss the reliability of the HV Mux circuitry and show plans to ensure reliability during production.

  20. Remote switch actuator

    Science.gov (United States)

    Haas, Edwin Gerard; Beauman, Ronald; Palo, Jr., Stefan

    2013-01-29

    The invention provides a device and method for actuating electrical switches remotely. The device is removably attached to the switch and is actuated through the transfer of a user's force. The user is able to remain physically removed from the switch site obviating need for protective equipment. The device and method allow rapid, safe actuation of high-voltage or high-current carrying electrical switches or circuit breakers.

  1. MW-scale ICRF plasma heating using IGBT switches in a multi-pulse scheme

    Science.gov (United States)

    Be'ery, I.; Kogan, K.; Seemann, O.

    2015-06-01

    Solid-state silicon switches are cheap and reliable option for 1-10 MHz RF power sources, required for plasma ion cyclotron RF heating (ICRF). The large `on' resistance of MOSFET and similar devices limits their power delivery to a few tens of kW per switch. Low resistivity devices, such as IGBT, suffer from large `off' switching time, which limits their useful frequency range and increases the power dissipated in the switch. Here we demonstrate more than 0.8 MW circulated RF power at 2 MHz using only three high voltage IGBT switches. The circuit uses the fast `on' switching capability of the IGBTs to generate high-Q pulse train. This operation mode also simplifies the measurement of RF coupling between the antenna and the plasma.

  2. Fault identification in crystalline silicon PV modules by complementary analysis of the light and dark current-voltage characteristics

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Sera, Dezso; Hacke, Peter

    2014-01-01

    Photovoltaic system (PV) maintenance and diagnostic tools are often based on performance models of the system, complemented with light current-voltage (I-V) measurements, visual inspection and/or thermal imaging. Although these are invaluable tools in diagnosing PV system performance losses...... or contacts are damaged/degraded). With the recent growth and development of new module level dc-dc optimizers and micro inverters, capable of bidirectional current flow, it is now possible to implement both dark I-V and light I-V measurements as complementary diagnostic tools. By complementing light I-V...... measurements, which reflect both the optical and electrical performance parameters of the PV device, with dark I-V measurements, which focus only on the electrical characteristic of the PV device, the optical factors determining power loss (such as partial shadows, soiling, discoloration of the plastic...

  3. Fault identification in crystalline silicon PV modules by complementary analysis of the light and dark current-voltage characteristics

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Sera, Dezso; Hacke, Peter

    2016-01-01

    (soiling, shading, discoloration). The premise of the method that is proposed is that different degradation modes affect the light and dark I-V characteristics of the PV module in different ways, leaving distinct signatures. This work focuses on identifying and correlating these specific signatures present......This article proposes a fault identification method, based on the complementary analysis of the light and dark current-voltage (I-V) characteristics of the photovoltaic (PV) module, to distinguish between four important degradation modes that lead to power loss in PV modules: (a) degradation...... in the light and dark I-V measurements, to specific degradation modes; a number of new dark I-V diagnostic parameters are proposed to quantify these signatures. The experimental results show that these dark I-V diagnostic parameters, complemented by light I-V performance and series resistance measurements can...

  4. Compact silicon-on-insulator-based 2 × 2 Mach-Zehnder interferometer electro-optic switch with low crosstalk

    Institute of Scientific and Technical Information of China (English)

    Jiejiang Xing; Zhiyong Li; Peiji Zhou; Yuanhao Gong; Yude Yu; Manqing Tan; Jinzhong Yu

    2015-01-01

    We report a compact 2 × 2 Mach-Zehnder interferometer (MZI) electro-optic switch fabricated on a siliconon-insulator using standard complementary metal-oxide semiconductor (CMOS) processes.With a short modulation arm length of 200 μm,the crosstalk is reduced to-22 dB by the new modulation scheme of push-pull modulation with a pre-biased π/2 phase shift.The new modulation scheme can also work with a fast switching time of about 5.4 ns.

  5. Manipulation of the coherent spatial and angular shifts of Goos-Hänchen effect to realize the digital optical switch in silicon-on-insulator waveguide corner

    Science.gov (United States)

    Sun, DeGui

    2016-11-01

    In this work, based on the quantum process of the Goos-Hänchen (GH) spatial shift, a quantum process of the GH angular shift is also theoretically investigated. Then, the coherence between spatial and angular shifts in the GH effect is discovered and developed to manipulate the final total displacement for a digital optical switch. It is found that a waveguide corner structure always makes the reflected guide-mode have a GH angular shift in the minus direction when the incident beam is in the Brewster angle vicinity, while it always makes the spatial shift in the plus direction. Meanwhile, the coherence of these two GH shifts has an interesting distribution with the incident angle, and only in the common linear response area to the incident angle, the two GH shifts are mutually enhancing, and then a mini refractive index modulation of the guided-mode at the reflecting interface can create a great stable jump of reflected beam displacement at an eigenstate under the GH effect. As a result, on the 220 nm CMOS-compatible silicon-on-insulator waveguide platform, with a tapered multimode interference (MMI) waveguide, a 5 × 1018cm-3 concentration variation of free carriers can create an absolute digital total displacement of 8-25 μm of the reflected beam on the MMI waveguide output end, leading to a 1 × 5 scale digital optical switching function.

  6. SiC merged p-n/Schottky rectifiers for high voltage applications

    Energy Technology Data Exchange (ETDEWEB)

    Held, R.; Kaminski, N.; Niemann, E. [Daimler-Benz AG, Frankfurt am Main (Germany). Forschung und Technik

    1998-08-01

    A method of reducing reverse currents and increasing breakdown voltages without inducing negative effects on switching behavior in silicon carbide Schottky diodes is proved successfully. Implantation of p-regions in the surface of the n-drift region below the Schottky metal form face to face p-n junctions which screen the Schottky contact from high electrical fields. This results in a reduction of the reverse current and an increase of the breakdown voltage to the limit of a `pure` SiC p-n diode. It is shown, that in contrast to silicon based devices, SiC merged p-n/Schottky (MPS) rectifier preserve their excellent unipolar switching behavior. (orig.) 5 refs.

  7. Pixel structures to compensate nonuniform threshold voltage and mobility of polycrystalline silicon thin-film transistors using subthreshold current for large-size active matrix organic light-emitting diode displays

    Science.gov (United States)

    Na, Jun-Seok; Kwon, Oh-Kyong

    2014-01-01

    We propose pixel structures for large-size and high-resolution active matrix organic light-emitting diode (AMOLED) displays using a polycrystalline silicon (poly-Si) thin-film transistor (TFT) backplane. The proposed pixel structures compensate the variations of the threshold voltage and mobility of the driving TFT using the subthreshold current. The simulated results show that the emission current error of the proposed pixel structure B ranges from -2.25 to 2.02 least significant bit (LSB) when the variations of the threshold voltage and mobility of the driving TFT are ±0.5 V and ±10%, respectively.

  8. 基于固态开关的单级冲击电压发生器设计与实现%Design and Implementation of a Single-stage Impulse Voltage Generator Based on Solid-state Switch

    Institute of Scientific and Technical Information of China (English)

    赵涛; 杨津鸣; 王资博; 郭沁; 郁利超; 高丽

    2016-01-01

    The power transformer in operation may be subjected to lightning overvoltage and switching overvoltage. Due to the difference of the voltage, rated power and design layout of the transformer, the overvoltage waveforms are usually very different with those in the IEC standards. So it is necessary to carry out the investigation about the typ⁃ical dielectric breakdown characteristic test under different wave parameters of impulse voltage. Therefore in this paper, an impulse voltage generator is built based on the solid state switch and it can produce different kinds of im⁃pulse voltage by adjusting the parameters of the capacitor and resistor, including standard lightning impulse voltage and switching impulse voltage of 7 kinds of impulse waveforms. Experimental tests show that the impulse waveforms between test and circuit simulation are very close, and the errors of the front and the tail time of the impulse wave⁃forms satisfy the standard deviation range.%电力变压器在运行过程中可能遭到雷电过电压和操作过电压的作用,由于其自身电压等级、额定功率和设计布局等差异,导致入侵的电压波形通常和IEC标准有很大不同,评估其绝缘强度时有必要开展不同波形参数冲击电压下典型绝缘击穿特性试验研究。为此设计并搭建了一套基于固态开关的冲击电压发生器,通过调节回路中电容和电阻参数,可产生包括标准雷电冲击电压和标准操作冲击电压等7种不同波形参数的冲击电压。实验测试与回路仿真所得波形近似,冲击电压的波头时间和波尾时间满足标准规定允许的偏差范围。

  9. Energy reversible switching from amorphous metal based nanoelectromechanical switch

    KAUST Repository

    Mayet, Abdulilah M.

    2013-08-01

    We report observation of energy reversible switching from amorphous metal based nanoelectromechanical (NEM) switch. For ultra-low power electronics, NEM switches can be used as a complementary switching element in many nanoelectronic system applications. Its inherent zero power consumption because of mechanical detachment is an attractive feature. However, its operating voltage needs to be in the realm of 1 volt or lower. Appropriate design and lower Young\\'s modulus can contribute achieving lower operating voltage. Therefore, we have developed amorphous metal with low Young\\'s modulus and in this paper reporting the energy reversible switching from a laterally actuated double electrode NEM switch. © 2013 IEEE.

  10. Active Q-switching in an erbium-doped fiber laser using an ultrafast silicon-based variable optical attenuator.

    Science.gov (United States)

    Chang, You Min; Lee, Junsu; Jhon, Young Min; Lee, Ju Han

    2011-12-19

    Presented herein is the use of an ultrafast Si-based variable optical attenuator (VOA) as a Q-switch for rare earth-doped fiber lasers. The ultrafast VOA is based on a forward-biased p-i-n diode integrated with a ridge waveguide, which was originally designed and optimized for WDM channel power equalization in optical communication systems. By incorporating a Si-based VOA with a transient time of ~410 ns into an erbium-doped fiber-based Fabry-Perot cavity it has been shown that stable Q-switched pulses possessing a temporal width of less than ~86 ns can be readily obtained at a repetition rate of up to ~1 MHz. The laser's peak power of ~38 W is shown to be obtainable at 20 kHz with a slope efficiency of ~21%.

  11. 低压智能馈电开关漏电保护的故障分析与改造%Fault analysis of leakage protection of smart low-voltage feed switch and its reformation

    Institute of Scientific and Technical Information of China (English)

    管振翔; 王光生; 姜涛; 刘士刚; 翟东; 范新留

    2013-01-01

    针对南屯煤矿井下低压智能馈电开关漏电保护出现的故障,分析了漏电保护原理及故障原因,并提出了改造方案:在总开关处通过附加电容来增大零序电流,以便综合保护装置能够进行采集、判断,使漏电支路分开关可靠动作;在分开关漏电检测回路中串接一个断路器常闭辅助接点,使分开关合闸后能够将附加直流电源式原理检测回路完全切除,消除对总开关漏电检测的干扰.现场应用结果表明,改造后的低压供电系统漏电保护运行正常,总开关漏电动作时间由原来的2 s缩短到250 ms以内,分开关漏电保护动作灵敏、可靠.%For faults in leakage protection of smart low-voltage feed switch of Nantun Coal Mine, the paper analyzed leakage protection principle and causes of the faults, and proposed reformation schemes: increase zero sequence current by additional capacitance at the master switch, so that integrated protector can be used for acquisition and judgment, and sub switch of the leakage branch can operate reliably; connect a circuit breaker auxiliary contact normally closed in series in leakage detection circuit of sub switch, so that detection circuit based on additional DC power principle can be cut off completely after closing of the sub switch to eliminate interference to leakage detection of master switch. Field application results show that the improved leakage protection of the low-voltage power supply system operates normally, leakage action time is shortened from 2 s to less than 250 ms, and the leakage protection of sub switch acts sensitively and reliably.

  12. A Voltage Controlled Oscillator for a Phase-Locked Loop Frequency Synthesizer in a Silicon-on-Sapphire Process

    Energy Technology Data Exchange (ETDEWEB)

    Garrison, Sean [Univ. of Missouri, Rolla, MO (United States)

    2009-05-21

    Engineers from a government-owned engineering and manufacturing facility were contracted by government-owned research laboratory to design and build an S-band telemetry transmitter using Radio Frequency Integrated Circuit (RFIC) technology packaged in a Low-Temperature Co-fired Ceramic (LTCC) Multi-Chip Module. The integrated circuit technology chosen for the Phase-Locked Loop Frequency Synthesizer portion of the telemetry transmitter was a 0.25 um CMOS process that utilizes a sapphire substrate and is fabricated by Peregrine Semiconductor corporation. This thesis work details the design of the Voltage Controlled Oscillator (VCO) portion of the PLL frequency synthesizer and constitutes an fully integrated VCO core circuit and a high-isolation buffer amplifier. The high-isolation buffer amplifier was designed to provide 16 dB of gain for 2200-3495 MHz as well as 60 dB of isolation for the oscillator core to provide immunity to frequency pulling due to RF load mismatch. Actual measurements of the amplifier gain and isolation showed the gain was approximately 5 dB lower than the simulated gain when all bond-wire and test substrate parasitics were taken into account. The isolation measurements were shown to be 28 dB at the high end of the frequency band but the measurement was more than likely compromised due to the aforementioned bond-wire and test substrate parasitics. The S-band oscillator discussed in this work was designed to operate over a frequency range of 2200 to 2300 MHz with a minimum output power of 0 dBm with a phase-noise of -92 dBc/Hz at a 100 kHz offset from the carrier. The tuning range was measured to be from 2215 MHz to 2330 MHz with a minimum output power of -7 dBm over the measured frequency range. A phase-noise of -90 dBc was measured at a 100 kHz offset from the carrier.

  13. Silicon Carbide Emitter Turn-Off Thyristor

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2008-01-01

    Full Text Available A novel MOS-controlled SiC thyristor device, the SiC emitter turn-off thyristor (ETO is a promising technology for future high-voltage switching applications because it integrates the excellent current conduction capability of a SiC thyristor with a simple MOS-control interface. Through unity-gain turn-off, the SiC ETO also achieves excellent Safe Operation Area (SOA and faster switching speeds than silicon ETOs. The world's first 4.5-kV SiC ETO prototype shows a forward voltage drop of 4.26 V at 26.5 A/cm2 current density at room and elevated temperatures. Tested in an inductive circuit with a 2.5 kV DC link voltage and a 9.56-A load current, the SiC ETO shows a fast turn-off time of 1.63 microseconds and a low 9.88 mJ turn-off energy. The low switching loss indicates that the SiC ETO could operate at about 4 kHz if 100 W/cm2 conduction and the 100 W/cm2 turn-off losses can be removed by the thermal management system. This frequency capability is about 4 times higher than 4.5-kV-class silicon power devices. The preliminary demonstration shows that the SiC ETO is a promising candidate for high-frequency, high-voltage power conversion applications, and additional developments to optimize the device for higher voltage (>5 kV and higher frequency (10 kHz are needed.

  14. Charge trapping and de-trapping in Si-nanoparticles embedded in silicon oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Sanchez, A.; Barreto, J.; Dominguez, C. [IMB-CNM (CSIC), Campus UAB, 08193 Bellaterra, Barcelona (Spain); Aceves, M.; Yu, Z. [INAOE, Electronics Department, Puebla, Pue., 72000 (Mexico); Luna, J.A. [CCMC, UNAM, Optics Department, Ensenada, BC, 22800 (Mexico)

    2008-07-01

    Electrical properties of silicon nanoparticles (Si-np's) embedded in a silicon oxide matrix were studied using MOS-like structures. Si-np's were created after silicon rich oxide (SRO) films were thermally annealed at 1100 C. Capacitance-voltage (C-V) characteristics showed downward and upward peaks in the accumulation region. Current-voltage (I-V) measurements exhibited current valleys and downward and upward peaks. Current versus time (I-t) measurements were also done at a negative constant gate voltage. A switching behaviour between two current states (ON and OFF) was observed. These effects have been related to the charge trapping and de-trapping of the Si-np's embedded in the SRO films. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. High voltage pulse generator. [Patent application

    Science.gov (United States)

    Fasching, G.E.

    1975-06-12

    An improved high-voltage pulse generator is described which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of the first rectifier connected between the first and second capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. The output voltage can be readily increased by adding additional charging networks. The circuit allows the peak level of the output to be easily varied over a wide range by using a variable autotransformer in the charging circuit.

  16. Study on an Automatic Knife Switch of New Type High-Voltage Small Current Reactor%新型高电压小电流电抗器自动刀闸的研究

    Institute of Scientific and Technical Information of China (English)

    许杰; 李世武; 孙伟

    2014-01-01

    针对当前电抗器投切刀闸存在的投切行程小、适用范围受限制、远程操控不方便等问题,研发了一种新型的高电压小电流电抗器自动刀闸,给出了自动刀闸结构图,分析了其工作原理。对该自动刀闸进行峰值耐受电流试验和机械操作试验,测试结果符合要求,有效通断率100%,提高了电抗器串并联自动化程度,易于远程控制且性能稳定,可广泛用于电力系统机构的各项试验。%Aiming at several problems such that the existing reactor knife switch is small in travel distance for knife making and breaking, limited in applicable range, not convenient in remote operating etc., this paper developed an automatic knife switch of new type high-voltage small current reactor and gave the structural diagram of the automatic knife switch, analyzing its working principle. The peak value withstand current and mechanical operating tests were carried out for the automatic knife switch. The test results are in conformity to the requirements, with 100% valid making-breaking rate, which raises the reactor serial and parallel connection automation degree, easy for remote control and stable in performance. The switch could be widely used in each test of electric power system organization.

  17. 双管Buck-Boost变换器的输入电压前馈控制策略%An Input Voltage Feedforward Control Strategy for Two-switch Buck-Boost DC-DC Converters

    Institute of Scientific and Technical Information of China (English)

    姚川; 阮新波; 曹伟杰; 陈沛琳

    2013-01-01

    The two-switch Buck-Boost (TSBB) converter is suitable for wide input voltage applications, and a two-mode control scheme with two modulation signals and one carrier can be adopted to achieve high efficiency and automatic modes-switching over the entire input voltage range. The corresponding operating modes are the Buck mode with high input voltages and the Boost mode with low input voltage. In order to reduce the influence of the input voltage disturbance on the output voltage, input voltage feed-forward (IVFF) functions based on the small-signal models of different operating modes were derived, and the effect of the variable circuit parameters on the IVFF functions was analyzed, then a two-mode control scheme with IVFF compensation was proposed. With this proposed control scheme for the TSBB converter, automatic selections of operating modes and the corresponding IVFF functions can be achieved simultaneously. Besides, nearly smooth switching between Buck and Boost modes is guaranteed. Then, high efficiency and improved input transient response over the entire input voltage range are both achieved. For exhibiting the advantages of the proposed control scheme clearly, comparisons between the two-mode control with and without IVFF compensation had been presented in this paper. Finally, a suitable power prototype was fabricated to validate the effectiveness of the control scheme.%  双管Buck-Boost变换器适用于宽输入电压范围场合。采用双调制–单载波的两模式控制策略可实现其整个输入电压范围内的高效率和工作模式的自动平滑切换,其工作模式即为高输入电压区间的 Buck 模式和低输入电压区间的Boost模式。为抑制输入电压扰动对输出电压的影响,通过建立双管Buck-Boost变换器不同工作模式下的小信号模型,推导相应的输入电压前馈函数,并分析电路参数变化对前馈函数的影响,进而提出一种带输入电压前馈的两模式控制

  18. Development of Electrostatic Actuator, which enables the Stable Contact Resistance, Driven at Low Voltage

    Science.gov (United States)

    Masuda, Takahiro; Seki, Tomonori; Miyaji, Takaaki; Sato, Fumihiko

    The switches play an important role in making the multifunctional radio communication circuit and therefore, the high-performance microminiaturized high-frequency switches are urgently expected. RF-MEMS switch with mechanical switching structure is hoped to improve both high-frequency signal loss and isolation quality simultaneously and to provide better linearity on the performance and compatibility to silicon-based circuit elements. But considering the applications, such as cellular phone and wireless-LAN, lower driving voltage and smaller switch dimensions are required. In order to solve these requirements, a novel electrostatic actuator with a unique structure of movable electrodes which enables the stable contact resistance is developed for RF-MEMS switches. This actuator has slits between the movable electrodes and the restoring spring. The electrostatic actuator with a movable electrode area of 0.5mm2 was driven at low voltage of 9-11V. And no defect due to restoration shortage is observed during switching test up to 400million cycles. In this paper, the results of mechanical design of the electrostatic actuator, the simulation, the experiments, and the reliability test are described

  19. 中压固态复合开关切除电容器组的建模与分析%Modeling and Analysis of Medium-voltage Solid-state Hybrid Switch for Turning-off Capacitor Bank

    Institute of Scientific and Technical Information of China (English)

    李卫国; 肖湘宁; 罗应立; 邱宇峰; 崔学深

    2013-01-01

    以真空断路器与晶闸管阀并联构成的中压固态复合开关切除电容器组的研究内容,主要是对电容器组负载电流由真空断路器至晶闸管阀之间电流转移这一暂态过程进行解析分析.首先基于真空断路器分段线性化电弧伏安特性曲线,并结合等效电路构建电流转移数学模型;然后据此推导出中压固态复合开关切除电容器组电流和晶闸管阀端电压解析解;最后据此可以得出晶闸管阀组最佳触发时刻、晶闸管阀组设计参数以及电流转移暂态过程中电流冲击程度.因为实现了由真空断路器至晶闸管阀的电流转移,所以电容器组在晶闸管阀电流自然过零时刻被切除,彻底克服固定电容器(fix capacitor,FC)开关分闸时造成的开关重燃和操作过电压.中压固态复合开关切除电容器负载暂态性能与晶闸管开关电容器(thyristor switch capacitor,TSC)性能基本一致,但却实现了紧凑化、低成本和高可靠性设计.利用仿真和现场录波波形验证了技术可行性.%In a medium-voltage solid-state hybrid switch (MV SSHS) which is made of the vacuum breaker and the thyristor valve in parallel connection, the transient process of switching off capacitor load is that the capacitor load current transfers from the vacuum breaker to the thyristor valve, then it can be cut off at the crossing zero point. Transient parse of the capacitor current and the voltage of thyristor valve was deduced based on the mathematics model which consist of dynamic snubber circuits of the thyristor valve, the piecewise linear voltage-current characteristic curve of arc, the series-wound reactor and capacitor. Accordingly the following result can be drawn: the optimal trigger time of the thyristor valve and the theoretical foundation for thyristor valve design are established in order to transfer the current from vacuum breaker to the thyristor valve. It can overcome reignition and overvoltage by

  20. Piezo Voltage Controlled Planar Hall Effect Devices

    OpenAIRE

    Bao Zhang; Kang-Kang Meng; Mei-Yin Yang; Edmonds, K. W.; Hao Zhang; Kai-Ming Cai; Yu Sheng; Nan Zhang; Yang Ji; Jian-Hua Zhao; Hou-Zhi Zheng; Kai-You Wang

    2015-01-01

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the pie...

  1. 30 CFR 18.47 - Voltage limitation.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Voltage limitation. 18.47 Section 18.47 Mineral... § 18.47 Voltage limitation. (a) A tool or switch held in the operator's hand or supported against his... particular voltage(s) are provided in the design and construction of the equipment, its wiring,...

  2. 低压智能电容器自适应过零投切技术的研究%Research on Adaptive Zero-Crossing Switching Technology of Low Voltage Intelligent Power Capacitor

    Institute of Scientific and Technical Information of China (English)

    王砼; 陈丽安; 刘涛

    2014-01-01

    提出了一种用于智能电容器的基于电压零点闭环控制的自适应过零同步投切技术。采用模拟电路检测电压零点以及反馈投切时刻,改进磁保持继电器驱动电路,简化采样计算环节,提高了磁保持继电器动作一致性和自适应控制的准确性、稳定性。试验结果表明,该技术具有稳定、可靠的自适应控制效果及对低压电容器投入涌流的限制作用。%An adaptive zero-crossing switching technology for intelligent power capacitor based on closed loop control of zero voltage was presented.Analog circuits were applied for catching zero point of voltage and feeding back switching time.The drive circuits of magnetic latching relay were improved so that its action time has greater consistency.By simplifying the process of sampling and calculating,the stability and accuracy of adaptive control have been improved.The experimental results show that this technology has a stable and reliable effect on adaptive control as well as the result of limiting the inrush current of switching power capacitor.

  3. A Study on Electronic Touching Time-delay Switch based on Zero Voltage%基于零电压电子触摸延时开关的研究

    Institute of Scientific and Technical Information of China (English)

    刘冰冰

    2013-01-01

      目前,我国市场上的各种电子延时开关产品琳琅满目,但普遍存在功能方面的弊端。文章以典型的应用电路为例进行深入分析与研究,指出存在问题和提出解决问题的方法。同时,着重介绍专利产品零电压电子触摸延时开关的工作原理及其优点,希望能带给读者全新的启示。%Nowadays, there are a wide variety of electronic touching time-delay switches in the market in China. However, those switches have some disadvantages on their functions. Based on the full analysis and in-depth research on a typical cir-cuit of this kind, the author points out the existing problems and also proposes a solution. The author attaches importance to introduce operating principle and advantages of the zero voltage electronic touching time-delay switches which is a patent product. In doing so, the author wishes to present readers with some enlightenment in this field.

  4. 永磁真空开关在低压无功补偿装置中的应用%Application of permanent magnet vacuum switch in low-voltage reactive power compensation installation

    Institute of Scientific and Technical Information of China (English)

    贾华; 王巍; 吕海霞

    2013-01-01

    “十二五”规划以来,为了改善内蒙古地区城市低压电网无功功率补偿不足等问题,提出了一种新型永磁真空开关控制的低压无功补偿装置,该装置由微控制器、投切电容器用永磁真空开关、熔断器、电容器等部件组成.通过DSP控制器从电网采集三相电压、电流等数据,并通过DSP控制器调节配电网各项参数.应用结果表明,该装置能有效调节内蒙古低压电网无功功率补偿不足,改善电能质量,降低能耗等问题,具有较好的实用意义.%Since the "12th Five-Year" Plan, in order to improve the insufficient reactive power compensation in Inner Mongolia city, a new permanent magnetism vacuum switch control of low voltage reactive compensation device was proposed, including micro controller, and shooting, cut with permanent magnet capacitor vacuum switch, fuse, capacitor, and etc. Through the DSP controller, three-phase voltage, current, and other data were collected from grid, and the parameters of distribution network were adjusted. The application results show that the device can effectively regulate the insufficient low voltage power grid reactive power compensation in Inner Mongolia city, improve the quality of power, and reduce the energy consumption with good practical significance.

  5. Soft-Switched Dual-Input DC-DC Converter Combining a Boost-Half-Bridge Cell and a Voltage-Fed Full-Bridge Cell

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2013-01-01

    for various applications, such as fuel cell and super-capacitor hybrid energy system. By fully using two high frequency transformers and a shared leg of switches, number of the power devices and associated gate driver circuits can be reduced. With phase-shift control, the converter can achieve ZVS turn...

  6. High PRF high current switch

    Science.gov (United States)

    Moran, Stuart L.; Hutcherson, R. Kenneth

    1990-03-27

    A triggerable, high voltage, high current, spark gap switch for use in pu power systems. The device comprises a pair of electrodes in a high pressure hydrogen environment that is triggered by introducing an arc between one electrode and a trigger pin. Unusually high repetition rates may be obtained by undervolting the switch, i.e., operating the trigger at voltages much below the self-breakdown voltage of the device.

  7. Design of the Switching Power Supply with Large Current and Low Voltage Based on SG3525%基于SG3525的大电流低电压开关电源设计

    Institute of Scientific and Technical Information of China (English)

    牟翔永; 张晓春; 林刚; 孙秀斌

    2013-01-01

    A design for the switching power supply with large current and low voltage is presented, which is based on the Pulse Width Modulator control circuit named SG3525. The DC/DC full-bridge converter is used for the main circuit of the switching power supply. The output signals of SG3525 drive IGBTs of the main circuit after photoelectric isolation and power amplifier. In order to achieve the stable output and the continuously adjustable current, the technologies of feedback and PWM are applied to the switching power supply. This paper introduces the specific design and the primary circuit parameters of the main circuit, the control circuit and the drive circuit. The experimental results show that the switching power supply can steadily operate and continuously regulate the output current from 45A to 90A.%  介绍了以脉宽调制控制电路SG3525为控制核心的大电流低电压开关电源的设计。该电源主电路采用DC/DC全桥变换器,SG3525输出信号经光电隔离、功率放大后驱动主电路开关管IGBT,应用反馈技术和PWM调制技术实现电源稳定输出和输出电流连续可调。文中给出了主电路和控制及驱动电路的具体设计及主要电路参数。试验结果表明,该电源工作稳定,实现了输出直流电流从45A到90A连续可调。

  8. Dynamic actuation methods for capacitive MEMS shunt switches

    Science.gov (United States)

    Khater, M. E.; Vummidi, K.; Abdel-Rahman, E. M.; Nayfeh, A. H.; Raman, S.

    2011-03-01

    We develop dynamic actuation methods for capacitive MEMS shunt switches. We show that the dynamic actuation voltage is significantly less than the static actuation voltage and demonstrate 60% reduction in the actuation voltage. We also show that this reduction in the actuation voltage depends on the specific dynamic switching technique adopted. For a given operating condition, the minimum realizable switching time is that obtained using static switching. However, we developed a dynamic switching method that yields comparable switching time to that minimum. We also found that squeeze-film damping is the dominant damping mechanism for a shunt switch with a relatively slender bridge (aspect ratio of 11:1).

  9. Derivation of linearized transfer functions for switching-mode regulations. Phase A: Current step-up and voltage step-up converters

    Science.gov (United States)

    Wong, R. C.; Owen, H. A., Jr.; Wilson, T. G.

    1981-01-01

    Small-signal models are derived for the power stage of the voltage step-up (boost) and the current step-up (buck) converters. The modeling covers operation in both the continuous-mmf mode and the discontinuous-mmf mode. The power stage in the regulated current step-up converter on board the Dynamics Explorer Satellite is used as an example to illustrate the procedures in obtaining the small-signal functions characterizing a regulated converter.

  10. Development of a portable low-cost and low-noise DC/DC high voltage switching power supply for optics application

    Energy Technology Data Exchange (ETDEWEB)

    Hung, K.-Y.; Chen, Y.-C. [Mingchi Univ. of Technology, Taishan, Taipei, Taiwan (China). Inst. of Mechanical and Electrical Engineering, Dept. of Mechanical Engineering

    2007-07-01

    A commercial power supply is bulky in size, very expensive and produces extremely noisy voltage, carrying approximately 45 mV of surge at the maximum. An avalanche photo diode (APD) is used to detect weak fluorescent signals, making it easy to generate extremely intensified noise, and degrading the S/N ratio. In order to resolve this problem, this paper discussed the development of a portable high voltage transformer-free direct current (DC) drive circuit module with low cost, noise, and power for photoelectric components. The module can be used on photoelectric components requiring high reverse voltage, such as APDs, piezo transformers, vacuum florescent displays, and micro electric machines. The low-noise module effectively reduced the thermal noise of photodiodes, leading to an improvement in the S/N ratio of photoelectric components by approximately 37 per cent. The module was described in detail. Several graphs and tables were presented, including a comparison between various types of converters; the design structure of the control unit circuit; and diagram of converted circuit diagram. It was concluded that the module was efficient, compact, and portable and designed with a transformer-free circuitry. In addition, the power supply module was successfully developed and would be much more feasible to use in developing portable products, such as digital cameras, and other advanced products. 1 tab., 4 figs.

  11. Fabrication of Silicon Based Novel Structure JBS Diode with Breakdown Voltage above 300 V%300V以上硅基新型JBS肖特基二极管的制备

    Institute of Scientific and Technical Information of China (English)

    王一帆; 王朝林; 刘肃; 何少博

    2011-01-01

    为了在保留传统肖特基二极管正向压降低、电流密度大优点的基础上,使其反向击穿电压提高到了300 v以上,我们采用硅材料做为衬底,肖特基结区采用蜂房结构,终端采用两道场限环结构加一道切断环结构,所制备的肖特基二极管在正向电流10A时,正向压降仅为0.79 V;同时在施加300 V反向电压时,反向漏电流在5μA以下.%To retain the advantages of traditional Schottky diodes, such as high current density under low forward voltage and improve their breakdown voltage to above 300 V, we fabricated silicon-based novel structure JBS diodes. Its Schottky barrier area is a honey comb structure, and its terminal is formed by two floating field limiting rings(FLRs) plus a cutoff ring structure. Its forward voltage-drop is only 0. 79 V under 10 A current, while its leakage current is less than 5 (xA when 300 V reverse voltage is applied.

  12. Analysis of the breakdown mechanism for an ultra high voltage high-side thin layer silicon-on-insulator p-channel low-density metal-oxide semiconductor

    Institute of Scientific and Technical Information of China (English)

    Zhuang Xiang; Qiao Ming; Zhang Bo; Li Zhao-Ji

    2012-01-01

    This paper discusses the breakdown mechanism and proposes a new simulation and test method of breakdown voltage (BV) for an ultra-high-voltage (UHV) high-side thin layer silicon-on-insulator (SOI) p-channel low-density metaloxide semiconductor (LDMOS).Compared with the conventional simulation method,the new one is more accordant with the actual conditions of a device that can be used in the high voltage circuit.The BV of the SOI p-channel LDMOS can be properly represented and the effect of reduced bulk field can be revealed by employing the new simulation method.Simulation results show that the off-state (on-state) BV of the SOI p-channel LDMOS can reach 741 (620) V in the 3-μm-thick buried oxide layer,50-un-length drift region,and at -400 V back-gate voltage,enabling the device to be used in a 400 V UHV integrated circuit.

  13. High Power Switching Transistor

    Science.gov (United States)

    Hower, P. L.; Kao, Y. C.; Carnahan, D. C.

    1983-01-01

    Improved switching transistors handle 400-A peak currents and up to 1,200 V. Using large diameter silicon wafers with twice effective area as D60T, form basis for D7 family of power switching transistors. Package includes npn wafer, emitter preform, and base-contact insert. Applications are: 25to 50-kilowatt high-frequency dc/dc inverters, VSCF converters, and motor controllers for electrical vehicles.

  14. 基于开关稳压电源与开关稳流电源并联系统的设计%Design of a power supply system using switching stabilized voltage supply and switching stabilized current supply in parallel

    Institute of Scientific and Technical Information of China (English)

    姚融融; 李纲园

    2014-01-01

    To improve the performance of the power, increase the ability of the power to adapt to changes in load, this paper will be designed a power supply system that is built with switch the voltage source and the switch current source in parallel.System uses the output current proportional allocation method at the voltage source and current source in parallel, the problem of output instability is solved af-ter the parallel switching power supply system, the actual parallel power system is constructed.Experi-ments show that this current is automatically allocated pro rata method, can achieve the stability of the power system output power.%为了改善电源的性能,提高电源对变化负载的适应能力,设计将开关电压源和开关电流源并联构建供电系统。系统采用电压源与电流源在输出端并联后按比例分配输出电流的方法,解决开关电源并联后供电系统输出不稳定的问题,构建了实际的并联电源系统。实验表明,采用该文的按比例自动分配电流的方法,可以实现电源系统的大功率稳定输出。

  15. 基于固体开关器件的新型高压脉冲驱动源%New high-voltage pulse driving source based on solid switch device

    Institute of Scientific and Technical Information of China (English)

    陈静; 周晓青

    2012-01-01

    The the circuit of the pulse source is introduced briefly. The switch theory of the power MOSFET is expatiated emphatically. The overdriving technique of the power MOSFET grid is investigated to improve the switch speed of the power MOSFET by simulation and experiments. Power MOSFET is used as a switch element in the technology. The ways of improving the output power of the pulse source are analyzed through integrating the techniques of several power MOSFETs in series or in parallel. A high-voltage wide pulse source with the amplitude of output pulse larger than 4 kv, the rise time less than 10 ns and the pulse width wider than 100 ns was obtained.%从MOSFET的开关基理,以仿真与电路实验相结合的方法,研究出了MOSFET栅极的“过”驱动技术,以此来提高MOSFET的开关速度.并结合多个MOSFET的串并联的级联技术,采用多管串联方法来提高脉冲源的输出脉冲幅度,采用多管并联方法来提高脉冲源的其输出脉冲功率,从而得到较大的脉冲宽度.在此研制出了输出脉冲幅度大于4kV、前沿小于10ns、脉冲宽度大于100ns的高压快脉冲源.

  16. 用于开关电源的高精度多基准带隙电压源设计%Design of High-Precision Multi-Bandgap Voltage Reference Circuit for Switching Power Supply

    Institute of Scientific and Technical Information of China (English)

    唐宁; 赵荣建; 李书馨

    2012-01-01

    Based on the analysis of conventional band-gap reference circuit, a novel multi-voltage band-gap reference source for switching power supply was proposed using curvature compensation, high power gain feedback and buffer isolation technologies. The circuit achieved a high power supply rejection ratio (PSRR) and low temperature drift coefficient. Simulation based on 0. 5 μm CMOS technology at process corner TT, showed that, in the temperature range from -25 °C to 150 ℃, the multi-voltage reference circuit had a temperature drift coefficient less than 3×106/℃ and a PSRR of -78 dB, and it was capable of delivering four reference voltages: -3 V, 1. 2 V, 1 V and 0. 2 V.%带隙基准源是开关电源的重要组成部分.在对传统带隙基准源电路进行分析的基础上,结合曲率校正技术、高增益反馈技术和缓冲隔离技术,提出了一款应用于开关电源的高电源抑制比、低温漂系数和多基准输出新型基准源电路.基于0.5μm CMOS工艺,对电路进行仿真.结果表明,在-25℃~150℃范围内和典型(TT)工艺角下,设计的基准源温漂系数小于3×10-6/℃,PSRR为-78 dB,可产生3V,1.2 V,1V,0.2V四个基准输出电压.

  17. Design and implementation of a switched capacitor-based embedded hybrid DC-DC converter

    Science.gov (United States)

    Bhattacharyya, Kaushik; Mandal, Pradip

    2012-06-01

    Here, we propose an integrated hybrid DC-DC converter suitable for high drop-out energy conscious applications. In the hybrid converter topology, along with a linear regulator two switched capacitors are used to store and recycle charge for better power efficiency. Without significant power loss the switched capacitors step down the supply voltage for the linear regulator working in low drop-out mode. The linear regulator, on the other hand, attenuates the voltage ripple that originates from the switched capacitors converter on its power supply rejection ratio. It also helps for line and load regulation. Additionally, a synthesised counter ripple is injected through the linear regulator to further reduce the output ripple. With these two techniques, for a moderate load current and an acceptable output ripple, the switching and load capacitors are reduced to a value which can be implemented within the chip. The proposed integrated converter circuit has been designed, implemented and tested in a 0.18 mm CMOS process for 3.3-1.3V conversion. With two switching capacitors of 210 pF each and 100 pF load capacitor, more than 13 mA of load current, measured peak-to-peak output voltage ripple is 146 mV. The achieved measured power efficiency is 64.97%. Exhaustive silicon characterisation of the converter is done to observe the power efficiency and ripple variation at different frequency of operations.

  18. Polarity-dependent conformational switching of a peptide mimicking the S4-S5 linker of the voltage-sensitive sodium channel.

    Science.gov (United States)

    Helluin, O; Breed, J; Duclohier, H

    1996-02-21

    The S4-S5 linker (or S45) in voltage-sensitive sodium channels was previously shown to be involved in the permeation pathway. The secondary structure, investigated by circular dichroism, of a S4-S45 peptide from domain IV and its fragments (including S45) is reported here and compared with that of the homologous peptide from domain II as a function of the solvent dielectric constant. The reduction in helicity seen for S4-S45 (II) in polar media is cancelled in membrane-like environment. The most striking result-- a sharp alpha-helix --> beta-sheet transition upon exposure of the S45 moiety to aqueous solvents-- is discussed as regards channel activation and selectivity.

  19. Piezo Voltage Controlled Planar Hall Effect Devices

    Science.gov (United States)

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K. W.; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-01

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  20. Piezo Voltage Controlled Planar Hall Effect Devices.

    Science.gov (United States)

    Zhang, Bao; Meng, Kang-Kang; Yang, Mei-Yin; Edmonds, K W; Zhang, Hao; Cai, Kai-Ming; Sheng, Yu; Zhang, Nan; Ji, Yang; Zhao, Jian-Hua; Zheng, Hou-Zhi; Wang, Kai-You

    2016-06-22

    The electrical control of the magnetization switching in ferromagnets is highly desired for future spintronic applications. Here we report on hybrid piezoelectric (PZT)/ferromagnetic (Co2FeAl) devices in which the planar Hall voltage in the ferromagnetic layer is tuned solely by piezo voltages. The change of planar Hall voltage is associated with magnetization switching through 90° in the plane under piezo voltages. Room temperature magnetic NOT and NOR gates are demonstrated based on the piezo voltage controlled Co2FeAl planar Hall effect devices without the external magnetic field. Our demonstration may lead to the realization of both information storage and processing using ferromagnetic materials.

  1. A New Asymmetrical Current-fed Converter with Voltage Lifting

    Directory of Open Access Journals (Sweden)

    DELSHAD, M.

    2011-05-01

    Full Text Available This paper presents a new zero voltage switching current-fed DC-DC converter with high voltage gain. In this converter all switches (main and auxiliary turn on under zero voltage switching and turn off under almost zero voltage switching due to snubber capacitor. Furthermore, the voltage spike across the main switch due to leakage inductance of forward transformer is absorbed. The flyback transformer which is connected to the output in series causes to high voltage gain and less voltage stress on the power devices. Considering high efficiency and voltage gain of this converter, it is suitable for green generated systems such as fuel cells or photovoltaic systems. The presented experimental results verify the integrity of the proposed converter.

  2. Specific features of the current–voltage characteristics of SiO{sub 2}/4H-SiC MIS structures with phosphorus implanted into silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Mikhaylova, A. I., E-mail: m.aleksey.spb@gmail.com; Afanasyev, A. V.; Ilyin, V. A.; Luchinin, V. V. [St. Petersburg State Electrotechnical University LETI (Russian Federation); Sledziewski, T. [Friedrich–Alexander–Universität Erlangen–Nürnberg (Germany); Reshanov, S. A.; Schöner, A. [Ascatron AB (Sweden); Krieger, M. [Friedrich–Alexander–Universität Erlangen–Nürnberg (Germany)

    2016-01-15

    The effect of phosphorus implantation into a 4H-SiC epitaxial layer immediately before the thermal growth of a gate insulator in an atmosphere of dry oxygen on the reliability of the gate insulator is studied. It is found that, together with passivating surface states, the introduction of phosphorus ions leads to insignificant weakening of the dielectric breakdown field and to a decrease in the height of the energy barrier between silicon carbide and the insulator, which is due to the presence of phosphorus atoms at the 4H-SiC/SiO{sub 2} interface and in the bulk of silicon dioxide.

  3. Design of a Polymer Directional Coupler Electro-Optic Switch with Low Push-Pull Switching Voltage at 1550nm%1550nm低推挽电压聚合物定向耦合电光开关的设计

    Institute of Scientific and Technical Information of China (English)

    郑传涛; 马春生; 闫欣; 王现银; 张大明

    2008-01-01

    A polymer directional coupler (DC) electro-optic switch with push-pull electrodes and rib waveguides is designed based on the conformal transforming method, image method, coupled mode theory, and electro-optic modulation theory. Its structure and principle are described, the design and optimization are performed, and the characteristics are analyzed,including the coupling length, switching voltage, output power, insertion loss, and crosstalk. To realize normal switching function, the fabrication tolerance, wavelength shift, and coupling loss between a single mode fiber (SMF) and the waveguide are discussed. Simulation results show that the coupling length is 3082μm; the push-pull switching voltage is 2.14V;and the insertion loss and crosstalk are less than 1.14 and -30dB, respectively. The proposed analytical technique on waveguides and electrodes is proven to be accurate and computationally efficient when compared with the beam propagation method (BPM) and the experimental results.%应用保角变换法、镜像法、耦合模理论和电光调制理论设计了一种推挽电极聚合物脊形波导定向耦合电光开关,阐述了基本结构和工作原理,给出了器件的设计和优化过程,主要分析了耦合长度、开关电压、输出光功率、插入损耗、串扰等特性.为了实现正常的开关功能,讨论了制作公差、波谱漂移以及单模光纤耦合损耗对器件性能的影响.模拟结果表明,所设计的开关的耦合长度为3082μm,开关电压为2.14V;插入损耗小于1.14dB,串扰小于-30dB.与BPM仿真结果以及实验结果的对比表明,文中提出的波导和电极的理论分析与计算方法具有较高的精度和可行性.

  4. A linear 180 nm SOI CMOS antenna switch module using integrated passive device filters for cellular applications

    Science.gov (United States)

    Jie, Cui; Lei, Chen; Peng, Zhao; Xu, Niu; Yi, Liu

    2014-06-01

    A broadband monolithic linear single pole, eight throw (SP8T) switch has been fabricated in 180 nm thin film silicon-on-insulator (SOI) CMOS technology with a quad-band GSM harmonic filter in integrated passive devices (IPD) technology, which is developed for cellular applications. The antenna switch module (ASM) features 1.2 dB insertion loss with filter on 2G bands and 0.4 dB insertion loss in 3G bands, less than -45 dB isolation and maximum -103 dB intermodulation distortion for mobile front ends by applying distributed architecture and adaptive supply voltage generator.

  5. Analyzing of Dynamic Voltage Restorer in Series Compensation Voltage

    Directory of Open Access Journals (Sweden)

    Naser Parhizgar

    2012-02-01

    Full Text Available The Dynamic Voltage Restorer (DVR is a series-connected compensator to generate a controllable voltage to against the short-term voltage disturbances. The technique of DVR is an effective and cost competitive approach to improve voltage quality at the load side. This study presents a single-phase and threephase DVR system with reduced switch-count topology to protect the sensitive load against abnormal voltage conditions. Most basic function, the DVR configuration consist of a two level Voltage Source Converter (VSC, a dc energy storage device, a coupling transformer Connected in shunt with the ac system This study presents the application of Dynamic Voltage Restorer (DVR on power distribution systems for mitigation of voltage sag at critical loads. DVR is one of the compensating types of custom power devices. The DVR, which is based on forced-commutated Voltage Source Converter (VSC has been proved suitable for the task of compensating voltage sags/swells. Simulation results are presented to illustrate and understand the performances of DVR in supporting load voltages under voltage sags/swells conditions.

  6. Sharp-switching band-modulation back-gated devices in advanced FDSOI technology

    Science.gov (United States)

    El Dirani, Hassan; Fonteneau, Pascal; Solaro, Yohann; Legrand, Charles-Alex; Marin-Cudraz, David; Ferrari, Philippe; Cristoloveanu, Sorin

    2017-02-01

    A band-modulation device with a free top surface, named Z3-FET (Zero front-gate, Zero swing slope and Zero impact ionization) and fabricated in the most advanced Fully Depleted Silicon-On-Insulator technology, is demonstrated experimentally. Since the device has no front gate, the operation mechanism is controlled by two adjacent heavily doped buried ground planes acting as back-gates. Characteristics such as sharp quasi-vertical switching, low leakage, and tunable trigger voltage are measured and discussed. We explore several variants (thin and thick silicon or SiGe body) and show promising results in terms of high current, switching performance and ESD capability with relatively low back-gate and drain bias operation.

  7. Magnetic switching

    Energy Technology Data Exchange (ETDEWEB)

    Birx, D.; Cook, E.; Hawkins, S.; Poor, S.; Reginato, L.; Schmidt, J.; Smith, M.

    1983-06-01

    The paper discusses the development program in magnetic switching which was aimed at solving the rep-rate and reliability limitations of the ATA spark gaps. The end result has been a prototype physically very similar to the present Advanced Test Accelerator (ATA) pulse power unit but vastly superior in performance. This prototype, which is easily adaptable to the existing systems, has achieved a burst rep-rate of 20 kHz and an output voltage of 500 kV. A one-on-one substitution of the existing pulse power module would result in a 100 MeV accelerator. Furthermore, the high efficiency of the magnetic pulse compression stages has allowed CW operation of the prototype at one kilohertz opening up other applications for the pulse power. Performance and design details will be described.

  8. Theoretical analysis and design of double implanted MOSFET on 6H silicon carbide wafer for low power dissipation and large breakdown voltage

    Directory of Open Access Journals (Sweden)

    Munish Vashishath

    2008-05-01

    Full Text Available This paper analyses the device structure of a 6H-SiC vertical double-implanted MOSFET (DIMOSFET in order to provide a high breakdown voltage of about 10 kV and a low power dissipation for a rise in device temperature of 600 oC. Analysis of an 800 W power dissipation for stable device operation corresponding to this temperature rise shows optimum doping levels of the drift region lying between 5*1013 cm-3 and 5*1015 cm-3 for a breakdown voltage of 10 kV.

  9. Low voltage switchgear breaker loss of pressure from the research and application of switch device%低压开关柜断路器失压自投装置的研究与应用

    Institute of Scientific and Technical Information of China (English)

    陈柳

    2013-01-01

    in view of the distribution network area of low voltage circuit breaker can vote, after pressure loss due to delay in sending, de-veloped a low- voltage circuit breaker based on time relay since loss of pressure switch device, the device delay through closing loop, avoid trans-former excitation inrush current, protection of power grid company and the user's device. Clever use of time relay sliding contact, after a set time delay sliding contact short after connect disconnected, analog manual switch button. Safe, reliable, economic, and greatly shortens the courts to re-cover their jurisdiction for sending time, reduces the customer outage time, reduce the work intensity of the operators, improve the customer satis-faction with the degree of power supply reliability.%针对配网台区低压断路器失压后不能自投,造成延误送电的情况,研发了一种基于时间继电器的低压断路器失压自投装置,该装置延时接通合闸回路,躲过变压器励磁涌流,保护电网公司与用户的设备。巧妙利用时间继电器的滑动触点,经过设定时间后,延时滑动触点短时接通后断开,模拟人工合闸按钮按下。该装置安全、可靠、经济,大大缩短了所辖台区恢复送电所用时间,减少了客户停电时间,减轻了运行人员的工作强度,提高了客户对于供电可靠性的满意程度。

  10. 三相电压型PWM整流器准定频直接功率控制%Novel Quasi Direct Power Control for Three-phase Voltage-source PWM Rectifiers With a Fixed Switching Frequency

    Institute of Scientific and Technical Information of China (English)

    杨达亮; 卢子广; 杭乃善; 李国进

    2011-01-01

    建立三相电压型脉宽调制(pulse width modulation,PWM)整流器在不同坐标系下的数学模型,分析直接功率控制(direct power control,DPC)的工作原理。针对直接功率控制中开关频率变化问题,通过对PWM整流器瞬时功率分析推导,提出一种内环直接采用电流控制的新型准定频直接功率控制策略。仿真验证了算法的可行性。采用PM300DVAl20智能功率模块,设计50kVA的三相电压型PWM整流器控制实验,在10kHz、5us的开关频率下获得良好的实验结果。实验结果表明,所提方法实现单位功率因数运行,与现行的DPC—SVM定频控制方法相比,具有更好的动静态响应性能。%This paper established the three-phase voltage-source pulse width modulation (PWM) rectifier mathematical models in different coordinate systems and analyzed the principle of direct power control (DPC). To alleviate the problem of variable switching frequency, a novel quasi DPC control strategy with current loop was represented through the analysis of PWM rectifier instantaneous power. The novel control strategy was proved feasible by the Matlab/Simulink simulation results. The 50kVA three-phase voltage-source PWM rectifier control experiment system was designed using PM300DVA120 intelligent power module (IPM), the excellent experiment results were given at the 10kHz switching frequency with 5μs dead time. The experimental results indicate that the PWM rectifier system achieves unity power factor operation and has better performance of dynamic and static response compared to the present space vector modulation (SVM) DPC fixed-frequency control method.

  11. Fundamental studies on the switching in liquid nitrogen environment using vacuum switches for application in future high-temperature superconducting medium-voltage power grids; Grundsatzuntersuchungen zum Schalten in Fluessigstickstoff-Umgebung mit Vakuumschaltern zur Anwendung in zukuenftigen Hochtemperatur-Supraleitungs-Mittelspannungsnetzen

    Energy Technology Data Exchange (ETDEWEB)

    Golde, Karsten

    2016-06-24

    By means of superconducting equipment it is possible to reduce the transmission losses in distribution networks while increasing the transmission capacity. As a result even saving a superimposed voltage level would be possible, which can put higher investment costs compared to conventional equipment into perspective. For operation of superconducting systems it is necessary to integrate all equipment in the cooling circuit. This also includes switchgears. Due to cooling with liquid nitrogen, however, only vacuum switching technology comes into question. Thus, the suitability of vacuum switches is investigated in this work. For this purpose the mechanics of the interrupters is considered first. Material investigations and switching experiments at ambient temperature and in liquid nitrogen supply information on potential issues. For this purpose, a special pneumatic construction is designed, which allows tens of thousands of switching cycles. Furthermore, the electrical resistance of the interrupters is considered. Since the contact system consists almost exclusively of copper, a remaining residual resistance and appropriate thermal losses must be considered. Since they have to be cooled back, an appropriate evaluation is given taking environmental parameters into account. The dielectric strength of vacuum interrupters is considered both at ambient temperature as well as directly in liquid nitrogen. For this purpose different contact distances are set at different interrupter types. A distinction is made between internal and external dielectric strength. Conditioning and deconditioning effects are minimized by an appropriate choice of the test circuit. The current chopping and resulting overvoltages are considered to be one of the few drawbacks of vacuum switching technology. Using a practical test circuit the height of chopping current is determined and compared for different temperatures. Due to strong scattering the evaluation is done using statistical methods. At

  12. Application of Current Sharing Technique in Low Voltage High Current Switching Power Supply%均流技术在低压大电流开关电源中的应用

    Institute of Scientific and Technical Information of China (English)

    王晓琴

    2016-01-01

    In the design of low-voltage high-current switching power supply, due to the relatively small output voltage, and large output current, in order to solve this problem, heterogeneous parallel is usually needed. In multiphase crisscross DC/DC converter, there is a problem of non-uniform current distribution, which will cause too large current in one phase causing damage and too small current in another phase failing to work normally. Aiming at this problem, the paper proposes using the HIP6303 HIP6602B and automatic flow technology, and the flow method is introduced in detail. Through theory and experiment, its current sharing effect is verified, thus the feasibility of the scheme is obtained.%在低压大电流开关电源的设计中,由于输出电压比较小,而输出电流又较大,为了解决此问题,通常需要多相并联,在多相交错的DC/DC变换器中,存在着电流分配不均匀的问题,电流分配不均匀,就会使得某相电流过大而损坏,某相电流过小而不能正常的工作。针对这个问题,文章提出了用HIP6303和HIP6602B进行自动均流的技术,并对这种均流方法进行了详细的论述,通过理论和实验,验证了其均流的效果,由此得出该方案的可行性。

  13. Control synthesis of switched systems

    CERN Document Server

    Zhao, Xudong; Niu, Ben; Wu, Tingting

    2017-01-01

    This book offers its readers a detailed overview of the synthesis of switched systems, with a focus on switching stabilization and intelligent control. The problems investigated are not only previously unsolved theoretically but also of practical importance in many applications: voltage conversion, naval piloting and navigation and robotics, for example. The book considers general switched-system models and provides more efficient design methods to bring together theory and application more closely than was possible using classical methods. It also discusses several different classes of switched systems. For general switched linear systems and switched nonlinear systems comprising unstable subsystems, it introduces novel ideas such as invariant subspace theory and the time-scheduled Lyapunov function method of designing switching signals to stabilize the underlying systems. For some typical switched nonlinear systems affected by various complex dynamics, the book proposes novel design approaches based on inte...

  14. Large arrays and properties of 3-terminal graphene nanoelectromechanical switches.

    Science.gov (United States)

    Liu, Xinghui; Suk, Ji Won; Boddeti, Narasimha G; Cantley, Lauren; Wang, Luda; Gray, Jason M; Hall, Harris J; Bright, Victor M; Rogers, Charles T; Dunn, Martin L; Ruoff, Rodney S; Bunch, J Scott

    2014-03-12

    Large arrays of 3-terminal nanoelectromechanical graphene switches are fabricated. The switch is designed with a novel geometry that leads to low actuation voltages and improved mechanical integrity, while reducing adhesion forces, which improves the reliability of the switch. A finite element model including non-linear electromechanics is used to simulate the switching behavior and to deduce a scaling relation between the switching voltage and device dimensions.

  15. VOLTAGE REGULATORS ASYNCHRONOUS GENERATORS

    Directory of Open Access Journals (Sweden)

    Grigorash O. V.

    2015-06-01

    Full Text Available A promising is currently the use of asynchronous generators with capacitive excitation as a source of electricity in stand-alone power systems. Drive asynchronous generators may exercise as a thermal engine and wind wheel wind power plant or turbines of small hydropower plants. The article discusses the structural and schematics of voltage stabilizers and frequency of asynchronous generators with improved operational and technical specifications. Technical novelty of design solutions of the magnetic system and stabilizers asynchronous generator of electricity parameters confirmed by the patents for the invention of the Russian Federation. The proposed technical solution voltage stabilizer asynchronous generators, can reduce the weight of the block capacitors excitation and reactive power compensation, as well as to simplify the control system power circuit which has less power electronic devices. For wind power plants it is an important issue not only to stabilize the voltage of the generator, but also the frequency of the current. Recommend functionality stabilizer schemes parameters of electric power made for direct frequency converters with artificial and natural switching power electronic devices. It is also proposed as part of stabilization systems use single-phase voltage, three-phase transformers with rotating magnetic field, reduce the level of electromagnetic interference generated by power electronic devices for switching, enhance the efficiency and reliability of the stabilizer.

  16. Switched-capacitor isolated LED driver

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, Seth R.; Kline, Mitchell

    2016-03-22

    A switched-capacitor voltage converter which is particularly well-suited for receiving a line voltage from which to drive current through a series of light emitting diodes (LEDs). Input voltage is rectified in a multi-level rectifier network having switched capacitors in an ascending-bank configuration for passing voltages in uniform steps between zero volts up to full received voltage V.sub.DC. A regulator section, operating on V.sub.DC, comprises switched-capacitor stages of H-bridge switching and flying capacitors. A current controlled oscillator drives the states of the switched-capacitor stages and changes its frequency to maintain a constant current to the load. Embodiments are described for isolating the load from the mains, utilizing an LC tank circuit or a multi-primary-winding transformer.

  17. Solid structures with bioorganic films on silicon

    Science.gov (United States)

    Tutov, E. A.

    2012-06-01

    The electrophysical parameters of ovalbumin/silicon and propolis/silicon heterostructures are studied using impedance spectroscopy and high-frequency capacitance-voltage characteristics under water vapor sorption conditions.

  18. Optimization Of Output Q-Switched Nd:YAG Laser Based On Switching Time

    Science.gov (United States)

    Tamuri, Abd Rahman; Daud, Yaacob Mat; Bidin, Noriah

    2010-07-01

    This paper reports the optimization of output Q-switch Nd:YAG. A free running Nd:YAG laser was employed as source of light. KD*P crystal was utilized as a Pockels cell. Avalanche transistor pulser was designed to switch a high voltage power supply. The switching time was conducted via a control unit based PIC16F84A microcontroller. The pulser was able to switch the voltage within 3 ns. The optimum switching time of Q-switching is obtained at 182.34 μs. The corresponding laser output is 40 mJ with pulse duration of 25 ns.

  19. 基于输入电压前馈补偿的开关变换器恒定导通时间控制技术%Constant on-Time Control of Switching DC-DC Converters Based on Input Voltage Feed-Forward Compensation

    Institute of Scientific and Technical Information of China (English)

    王金平; 许建平; 兰燕妮; 徐杨军

    2012-01-01

    针对恒定导通时间(COT)控制开关变换器的开关频率随输入电压变动而变化的缺点,本文提出了一种基于输入电压前馈补偿的恒定导通时间(IVFC-COT)控制技术,通过引入输入电压前馈环路,使恒定导通时间与输入电压成反比,从而消除输入电压波动对开关频率的影响。IVFC-COT控制在继承COT控制环路设计简单,无需误差放大器及其相应的补偿网络,瞬态响应速度快等优点的基础上,使开关频率在输入电压或负载波动时保持恒定。仿真及实验结果验证了IVFC-COT控制技术的可行性。%In order to make the switching frequency of constant on-time(COT)control technique immunity to the variation of input voltage, input voltage feed-forward compensated COT (IVFC-COT) control technique is proposed in this paper. By introducing input voltage feed-forward compensation, the on time is inverse proportion to the input voltage, and the effect of input voltage variation on switching frequency is eliminated. Similar to COT control technique, IVFC-COT also has simple control loop and fast transient response, moreover, error amplifier and its corresponding compensation network are not needed. In addition, it can make the switching frequency independent of the variation of input voltage and load. Simulation and experimental results are verified the validity of the proposed IVFC-COT control technique.

  20. Ultrafast pulse generation in photoconductive switches

    DEFF Research Database (Denmark)

    Keil, Ulrich Dieter Felix; Dykaar, D. R.

    1996-01-01

    Carrier and field dynamics in photoconductive switches are investigated by electrooptic sampling and voltage-dependent reflectivity measurements. We show that the nonuniform field distribution due to the two-dimensional nature of coplanar photoconductive switches, in combination with the large...... difference in the mobilities of holes and electrons, determine the pronounced polarity dependence. Our measurements indicate that the pulse generation mechanism is a rapid voltage breakdown across the photoconductive switch and not a local field breakdown...

  1. Amorphous metal based nanoelectromechanical switch

    KAUST Repository

    Mayet, Abdulilah M.

    2013-04-01

    Nanoelectromechanical (NEM) switch is an interesting ultra-low power option which can operate in the harsh environment and can be a complementary element in complex digital circuitry. Although significant advancement is happening in this field, report on ultra-low voltage (pull-in) switch which offers high switching speed and area efficiency is yet to be made. One key challenge to achieve such characteristics is to fabricate nano-scale switches with amorphous metal so the shape and dimensional integrity are maintained to achieve the desired performance. Therefore, we report a tungsten alloy based amorphous metal with fabrication process development of laterally actuated dual gated NEM switches with 100 nm width and 200 nm air-gap to result in <5 volts of actuation voltage (Vpull-in). © 2013 IEEE.

  2. 基于MATLAB的高压厂用变压器空载合闸仿真%No-load Switching Simulation of High Voltage Auxiliary Transformer Based on MATLAB

    Institute of Scientific and Technical Information of China (English)

    王青亚; 陈灵峰

    2016-01-01

    二次谐波制动方式作为防止变压器差动保护误动的一种可靠方式。利用MATLAB软件的simulink对华东桐柏抽水蓄能电站高压厂用变压器建立仿真模型,对厂变空载合闸时的励磁涌流进行了仿真,并用powergui模块对空载合闸时不同合闸初相角下励磁涌流中的二次谐波含量进行分析,从而为变压器差动保护中的二次谐波制动定值的整定提供理论依据,避免了变压器空载合闸、外部短路故障切除电压突然恢复时或厂变有很大励磁涌流流过时差动保护的误动。%As a way to prevent the malfunction of transformer differential protection, the 2nd-harmonic braking method is of high reliability. In this paper, the characteristics of magnetizing inrush current is analyzed, and a simulation model of high voltage transformer in power plant is established based on SIMULINK of MATLAB software. The magnetizing inrush current of unit transformer in no-load closing is also simulated, and the second harmonic content of inrush current is ana-lyzed by using Powergui module of different closing phase angle in no-load closing, thus the theoretical basis for second har-monic brake of transformer differential protection fixed value setting is provided, therefore, to avoid the differential protec-tion malfunction in transformer no-load switching or transformer flowing through large magnetizing inrush current when volt-age suddenly recovers after cutting off external short circuit fault.

  3. Silicon Carbide Diodes Characterization at High Temperature and Comparison With Silicon Devices

    Science.gov (United States)

    Lebron-Velilla, Ramon C.; Schwarze, Gene E.; Gardner, Brent G.; Adams, Jerry D., Jr.

    2004-01-01

    Commercially available silicon carbide (SiC) Schottky diodes from different manufacturers rated at 200, 300, 600, and 1200 V, were electrically tested and characterized as a function of temperature up to 300 C. Electrical tests included both steady state and dynamic tests. Steady state tests produced forward and reverse I-V characteristic curves. Transient tests evaluated the switching performance of the diodes in either a hard-switched DC to DC buck converter or a half-bridge boost converter. For evaluation and comparison purposes, the same tests were performed with current state-of-the-art ultra fast silicon (Si) pn-junction diodes of similar ratings and also a Si Schottky diode. The comparisons made were forward voltage drop at rated current, reverse current at rated voltage, and turn-off peak reverse recovery current and reverse recovery time. In addition, efficiency measurements were taken for the buck DC to DC converter using both the SiC Schottky diodes and the Si pn-junction diodes at different temperatures and frequencies. The test results showed that at high temperature, the forward voltage drop for SiC Schottky diodes is higher than the forward drop of the ultra fast Si pn-junction diodes. As the temperature increased, the forward voltage drop of the SiC Schottky increased while for the ultra fast Si pn-junction diodes, the forward voltage drop decreased as temperature increased. For the elevated temperature steady state reverse voltage tests, the SiC Schottky diodes showed low leakage current at their rated voltage. Likewise, for the transient tests, the SiC Schottky diodes displayed low reverse recovery currents over the range of temperatures tested. Conversely, the Si pn-junction diodes showed increasing peak reverse current values and reverse recovery times with increasing temperature. Efficiency measurements in the DC to DC buck converter showed the advantage of the SiC Schottky diodes over the ultra fast Si pn-junction diodes, especially at the

  4. 5.8kV SiC PiN Diode for Switching of High-Efficiency Inductive Pulsed Plasma Thruster Circuits

    Science.gov (United States)

    Toftul, Alexandra; Polzin, Kurt A.; Hudgins, Jerry L.

    2014-01-01

    Inductive Pulsed Plasma Thruster (IPPT) pulse circuits, such as those needed to operate the Pulsed Inductive Thruster (PIT), are required to quickly switch capacitor banks operating at a period of µs while conducting current at levels on the order of at least 10 kA. [1,2] For all iterations of the PIT to date, spark gaps have been used to discharge the capacitor bank through an inductive coil. Recent availability of fast, high-power solid state switching devices makes it possible to consider the use of semiconductor switches in modern IPPTs. In addition, novel pre-ionization schemes have led to a reduction in discharge energy per pulse for electric thrusters of this type, relaxing the switching requirements for these thrusters. [3,4] Solid state switches offer the advantage of greater controllability and reliability, as well as decreased drive circuit dimensions and mass relative to spark gap switches. The use of solid state devices such as Integrated Gate Bipolar Transistors (IGBTs), Gate Turn-off Thyristors (GTOs) and Silicon-Controlled Rectifiers (SCRs) often involves the use of power diodes. These semiconductor devices may be connected antiparallel to the switch for protection from reverse current, or used to reduce power loss in a circuit by clamping off current ringing. In each case, higher circuit efficiency may be achieved by using a diode that is able to transition, or 'switch,' from the forward conducting state ('on' state) to the reverse blocking state ('off' state) in the shortest amount of time, thereby minimizing current ringing and switching losses. Silicon Carbide (SiC) PiN diodes offer significant advantages to conventional fast-switching Silicon (Si) diodes for high power and fast switching applications. A wider band gap results in a breakdown voltage 10 times that of Si, so that a SiC device may have a thinner drift region for a given blocking voltage. [5] This leads to smaller, lighter devices for high voltage applications, as well as reduced

  5. Low voltage electron emission from[Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}]{sub 0.72}[PbTiO{sub 3}]{sub 0.28} single crystals induced by ferroelectric polarization switching

    Energy Technology Data Exchange (ETDEWEB)

    Mieth, Oliver; Eng, Lukas M. [Institute of Applied Physics, Technische Universitaet, Dresden (Germany); Vidyarthi, Vinay S.; Gerlach, Gerald [Institute for Solid State Electronics, Technische Universitaet, Dresden (Germany); Doerr, Kathrin [Institute for Metallic Materials, IFW Dresden, D-01069 Dresden (Germany)

    2009-07-01

    Here we report on electron emission from[Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}]{sub 0.72}[PbTiO{sub 3}]{sub 0.28} (PMN-PT) thin ferroelectric single crystals at ultra-low voltages down to 20 V per 400 {mu}m thickness, and for up to 10{sup 9} switching cycles. PMN-PT samples were prepared with split gold top electrodes exhibiting a 25 {mu}m wide gap region. Applying a sinusoidal voltage between the two top electrodes and the bottom electrode initiated electron emission from the gap region. The emitted electrons were collected under UHV conditions using two single electron counters arranged under an angle of 90 . Two emission regimes have been identified, which are clearly separated by the onset of complete ferroelectric polarization switching. This is also confirmed by recording nanoscale ferroelectric hysteresis loops by means of Piezoresponse Force Microscopy. The emitted electrons are found to have a broad energy distribution with the maximum kinetic energies reaching 110 eV and 50 eV for applied switching voltages of 140 V and 110 V, respectively. Our results confirm that polarization reversal is the governing mechanism behind the electron emission process.

  6. Top-Emitting Organic Light-Emitting Devices Based on Silicon Substrate with High Luminance and Low Turn-on Voltage

    Institute of Scientific and Technical Information of China (English)

    WU Zhi-Jun; CHEN Shu-Fen; YANG Hui-Shan; ZHAO Yi; LI Chuan-Nan; HOU Jing-Ying; LIU Shi-Yong

    2005-01-01

    @@ We have fabricated a top- emitting organic light-emitting device on silicon substrate with high yellow luminance based on 5,6,11,12-tetraphenylnaphthacene sub-monolayer. It consists of a thin layer of highly conductive silver as the semitransparent cathode and surfaced-modified Ag as the anode. The device turns on at 3 V with the luminance of 8.4 cd/m2. The maximum current efficiency is 1.3 cd/A at 6 V and the luminance reaches 14790 cd/m2at 14 V. The performance of the device is excellent in top-emitting organic light-emitting devices according to our knowledge.

  7. A Revive on 32×32 Bit Multiprecision Dynamic Voltage Scaling Multiplier with Operands Scheduler

    Directory of Open Access Journals (Sweden)

    Mrs.S.N.Rawat

    2016-02-01

    Full Text Available In this paper, we present a Multiprecision (MP reconfigurable multiplier that incorporates variable precision, parallel processing (PP, razor-based dynamic voltage scaling (DVS, and dedicated MP operands scheduling to provide optimum performance for a variety of operating conditions. All of the building blocks of the proposed reconfigurable multiplier can either work as independent smaller-precision multipliers or work in parallel to perform higher-precision multiplications. Given the user’s requirements (e.g., throughput, a dynamic voltage/ frequency scaling management unit configures the multiplier to operate at the proper precision and frequency. Adapting to the run-time workload of the targeted application, razor flip-flops together with a dithering voltage unit then configure the multiplier to achieve the lowest power consumption. The single-switch dithering voltage unit and razor flip-flops help to reduce the voltage safety margins and overhead typically associated to DVS to the lowest level. The large silicon area and power overhead typically associated to reconfigurability features are removed. Finally, the proposed novel MP multiplier can further benefit from an operands scheduler that rearranges the input data, hence to determine the optimum voltage and frequency operating conditions for minimum power consumption. This low-power MP multiplier is fabricated in AMIS 0.35-μm technology. Experimental results show that the proposed MP design features a 28.2% and 15.8% reduction in circuit area and power consumption compared with conventional fixed-width multiplier. When combining this MP design with error-tolerant razor-based DVS, PP, and the proposed novel operands scheduler, 77.7%–86.3% total power reduction is achieved with a total silicon area overhead as low as 11.1%. This paper successfully demonstrates that a MP architecture can allow more aggressive frequency/supply voltage scaling for improved power efficiency

  8. Effective electro-optical modulation with high extinction ratio by a graphene-silicon microring resonator

    DEFF Research Database (Denmark)

    Ding, Yunhong; Zhu, Xiaolong; Xiao, Sanshui

    2015-01-01

    comprehensively study the interaction between graphene and a microring resonator, and its influence on the optical modulation depth. We demonstrate graphene-silicon microring devices showing a high modulation depth of 12.5 dB with a relatively low bias voltage of 8.8 V. On-off electro-optical switching......Graphene opens up for novel optoelectronic applications thanks to its high carrier mobility, ultra-large absorption bandwidth, and extremely fast material response. In particular, the opportunity to control optoelectronic properties through tuning of the Fermi level enables electro-optical...... modulation, optical-optical switching, and other optoelectronics applications. However, achieving a high modulation depth remains a challenge because of the modest graphene-light interaction in the graphene-silicon devices, typically, utilizing only a monolayer or few layers of graphene. Here, we...

  9. Effects of adsorbed proteins, an antifouling agent and long-duration DC voltage pulses on the impedance of silicon-based neural microelectrodes.

    Science.gov (United States)

    Sommakia, Salah; Rickus, Jenna L; Otto, Kevin J

    2009-01-01

    The successful use of implantable neural microelectrodes as neuroprosthetic devices depends on the mitigation of the reactive tissue response of the brain. One of the factors affecting the ultimate severity of the reactive tissue response and the in vivo electrical properties of the microelectrodes is the initial adsorption of proteins onto the surface of the implanted microelectrodes. In this study we quantify the increase in microelectrode impedance magnitude at physiological frequencies following electrode immersion in a 10% bovine serum albumin (BSA) solution. We also demonstrate the efficacy of a common antifouling molecule, poly(ethylene glycol) (PEG), in preventing a significant increase in microelectrode impedance. In addition, we show the feasibility of using long-duration DC voltage pulses to remove adsorbed proteins from the microelectrode surface.

  10. Delta: a charge sensitive front-end amplifier with switched gain for low-noise, large dynamic range silicon detector readout

    NARCIS (Netherlands)

    Aspell, P.; Barney, D.; Bloch, P.; Jarron, P.; Lofstedt, B.; Reynaud, S.; Tabbers, P.

    2001-01-01

    The design and results of a radiation hard switched gain charge amplifier optimised for a large dynamic range and large input capacitance are described. The peaking time is 25 ns, dynamic ranges are 0.1–50 minimum ionising particles (MIPs) (high gain) and 1–400 MIPs (low gain), signal to noise (S/N)

  11. Rad-hard vertical JFET switch for the HV-MUX system of the ATLAS upgrade Inner Tracker

    CERN Document Server

    Fernandez-Martinez, Pablo; Flores, David; Hidalgo, Salvador; Quirion, David; Lynn, David

    2016-01-01

    This work presents a new silicon vertical JFET (V-JFET) device, based on the trenched 3D-detector technology developed at IMB-CNM, to be used as switches for the High-Voltage powering scheme of the ATLAS upgrade Inner Tracker. The optimization of the device characteristics is performed by 2D and 3D TCAD simulations. Special attention has been paid to the on-resistance and the switch-off and breakdown voltages to meet the specific requirements of the system. In addition, a set of parameter values has been extracted from the simulated curves to implement a SPICE model of the proposed V-JFET transistor. As these devices are expected to operate under very high radiation conditions during the whole experiment life-time, a study of the radiation damage effects and the expected degradation on the device performance is also presented at the end of the paper.

  12. Optically-triggered GaAs thyristor switches: Integrated structures for environmental hardening

    Energy Technology Data Exchange (ETDEWEB)

    Carson, R.F.; Weaver, H.T.; Hughes, R.C.; Zipperian, T.E.; Brennan, T.M.; Hammons, B.E.

    1990-01-01

    Optically-triggered thyristor switches often operate in adverse environments, such as high temperature and high dose-rate transient radiation, which can result in lowered operating voltage and premature triggering. These effects can be reduced by connecting or monolithically integrating a reverse-biased compensating photodiode or phototransistor into the gate of the optically-triggered thyristor. We have demonstrated the effectiveness of this hardening concept in silicon thyristors packaged with photodiodes, and in gallium arsenide optically-triggered thyristors monolithically integrated with compensating phototransistors.

  13. Transformerless DC-DC Converter Using Cockcroft-Walton Voltage Multiplier to Obtain High DC Voltage

    Directory of Open Access Journals (Sweden)

    Meghana G Naik,

    2014-11-01

    Full Text Available In the present scenario the use of transformer for high voltages in converter circuit reduces the overall operating efficiency due to leakage inductance and use of transformer also increases the operational cost. . Therefore the proposed system is implemented with transformer less DC-DC converter so as to obtain high DC voltage with the use of nine stage Cockcroft-Walton (CW voltage multiplier. The proposed converter operates in CCM (continuous conduction mode, so that the converter switch stress, the switching losses are reduced. The DC voltage at the input of the proposed model is low and is boosted up by boost inductor (Ls in DC-DC converter stage and performs inverter operation. The number of stages in CW-voltage multiplier circuit is applied with low input pulsating DC (AC Voltage voltage where it is getting converted to high DC output voltage. The proposed converter switches operates at two independent frequencies, modulating (fsm andalternating (fsc frequency. The fsm operates at higher frequency of the output while the fsc operates at lower frequency of the desired output voltage ripple and the output ripples can be adjusted by the switch Sc1 and Sc2. The regulation of the output voltage is achieved by controlling the Duty ratio.The simulation is carried over by the MATLABSIMULINK.

  14. Switching in electrical transmission and distribution systems

    CERN Document Server

    Smeets, René; Kapetanovic, Mirsad; Peelo, David F; Janssen, Anton

    2014-01-01

    Switching in Electrical Transmission and Distribution Systems presents the issues and technological solutions associated with switching in power systems, from medium to ultra-high voltage. The book systematically discusses the electrical aspects of switching, details the way load and fault currents are interrupted, the impact of fault currents, and compares switching equipment in particular circuit-breakers. The authors also explain all examples of practical switching phenomena by examining real measurements from switching tests. Other highlights include: up to date commentary on new develo

  15. Parallel Connection of Silicon Carbide MOSFETs for Multichip Power Modules

    DEFF Research Database (Denmark)

    Li, Helong

    characterization of SiC MOSFETs regarding the influence of switching loop stray inductance and common source stray inductance. The pulse current measurement methods of fast switching speed power devices are summarized and a new method witch silicon steel current transformer is presented. With the knowledge....... Then the DBC layout of a power module with paralleled SiC MOSFETs is presented and mathematically analyzed considering the influence of the circuit mismatch among the paralleled dies. It is revealed that there is a large common source stray inductance mismatch among the paralleled SiC MOSFETs, which leads...... the current sharing performance among the paralleled SiC MOSFET dies in the power module. The proposed DBC layout is not only limited for SiC MOSFETs, but also for Si IGBTs and other voltage controlled devices. of the circuit mismatch on the paralleled connection of SiC MOSFETs. It reveals the circuit...

  16. Photon-counting techniques with silicon avalanche photodiodes

    Science.gov (United States)

    Dautet, Henri; Deschamps, P.; Dion, Bruno; MacGregor, Andrew D.; MacSween, D.; McIntyre, Robert J.; Trottier, C.; Webb, Paul P.

    1993-05-01

    Silicon avalanche photodiodes (APD) have been used for photon counting for a number of years. This paper reviews their properties and the associated electronics required for photon counting in the Geiger mode. Significant improvements are reported in overall photon detection efficiencies (approaching 75% at 633 nm), and timing jitter (under 200 ps) achieved at high over-voltages (20 - 30 V). Results obtained using an active-mode fast quench circuit capable of switching over-voltages as high as 20 V (giving photon detection efficiencies in the 50% range), are reported with a dead-time of less than 50 ns. Larger diodes (up to 1 mm diameter), usable in the Geiger mode, which have quantum efficiencies over 80% in the 500 - 800 nm range also are reported.

  17. Determination of active doping in highly resistive boron doped silicon nanocrystals embedded in SiO{sub 2} by capacitance voltage measurement on inverted metal oxide semiconductor structure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tian, E-mail: tianz@student.unsw.edu.au; Puthen-Veettil, Binesh; Wu, Lingfeng; Jia, Xuguang; Lin, Ziyun; Yang, Terry Chien-Jen; Conibeer, Gavin; Perez-Wurfl, Ivan [Australian Centre for Advanced Photovoltaics, UNSW Australia, Kensington, New South Wales 2052 (Australia)

    2015-10-21

    We investigate the Capacitance-Voltage (CV) measurement to study the electrically active boron doping in Si nanocrystals (ncSi) embedded in SiO{sub 2}. The ncSi thin films with high resistivity (200–400 Ω cm) can be measured by using an inverted metal oxide semiconductor (MOS) structure (Al/ncSi (B)/SiO{sub 2}/Si). This device structure eliminates the complications from the effects of lateral current flow and the high sheet resistance in standard lateral MOS structures. The characteristic MOS CV curves observed are consistent with the effective p-type doping. The CV modeling method is presented and used to evaluate the electrically active doping concentration. We find that the highly boron doped ncSi films have electrically active doping of 10{sup 18}–10{sup 19 }cm{sup −3} despite their high resistivity. The saturation of doping at about 1.4 × 10{sup 19 }cm{sup −3} and the low doping efficiency less than 5% are observed and discussed. The calculated effective mobility is in the order of 10{sup −3} cm{sup 2}/V s, indicating strong impurity/defect scattering effect that hinders carriers transport.

  18. Determination of active doping in highly resistive boron doped silicon nanocrystals embedded in SiO2 by capacitance voltage measurement on inverted metal oxide semiconductor structure

    Science.gov (United States)

    Zhang, Tian; Puthen-Veettil, Binesh; Wu, Lingfeng; Jia, Xuguang; Lin, Ziyun; Yang, Terry Chien-Jen; Conibeer, Gavin; Perez-Wurfl, Ivan

    2015-10-01

    We investigate the Capacitance-Voltage (CV) measurement to study the electrically active boron doping in Si nanocrystals (ncSi) embedded in SiO2. The ncSi thin films with high resistivity (200-400 Ω cm) can be measured by using an inverted metal oxide semiconductor (MOS) structure (Al/ncSi (B)/SiO2/Si). This device structure eliminates the complications from the effects of lateral current flow and the high sheet resistance in standard lateral MOS structures. The characteristic MOS CV curves observed are consistent with the effective p-type doping. The CV modeling method is presented and used to evaluate the electrically active doping concentration. We find that the highly boron doped ncSi films have electrically active doping of 1018-1019 cm-3 despite their high resistivity. The saturation of doping at about 1.4 × 1019 cm-3 and the low doping efficiency less than 5% are observed and discussed. The calculated effective mobility is in the order of 10-3 cm2/V s, indicating strong impurity/defect scattering effect that hinders carriers transport.

  19. Base Transport and Vertical Profile Engineering in SILICON/SILICON(1-X) Germanium(x)/silicon Heterojunction Bipolar Transistors

    Science.gov (United States)

    Prinz, Erwin Josef

    1992-01-01

    outdiffusion from the Si_ {1-x}Ge_{x} base into the silicon collector degrade the Early voltage drastically. Finally, a novel Double-Base HBT is developed which increases the functionality of a HBT. Temperature -dependent measurements prove that the DC characteristics of the DB-HBT can be modeled using a version of charge -control theory. Switching is demonstrated in a single -transistor NAND gate at temperatures up to 150 K.

  20. Generator of ultrashort megavolt voltage pulses

    CERN Document Server

    Zheltov, K A; Shalimanov, V F

    2002-01-01

    Paper describes approx 3 ns duration and > 1 MW amplitude voltage pulse generator under high-ohmic (approx 450 Ohm) load. Generator comprises pulse transformer with magnetized core, as well as, resonance tuned circuit of high-voltage solenoid and accumulating spaces of a shaping line containing, moreover, spark gap to switch charge in transmitting line. Paper contains the results of voltage measuring in generator basic units

  1. Analytical and Practical Analysis of Switched-Capacitor DC-DC Converters

    Science.gov (United States)

    2006-09-01

    switches between these two frequency levels to keep the voltage on the output capacitor between two hysteresis levels vhi and vlo. These voltages are...defined to be slightly higher and slightly lower than the desired output voltage. When the output voltage exceeds vhi , the switching frequency is set

  2. Advanced High Power DC-DC Converter using A Novel Type Voltage Source Full-Bridge Soft-Switching PWM Inverter with High Frequency Transformer Link for Arc Welding Applications

    Science.gov (United States)

    Morimoto, Keiki; Doi, Toshimitsu; Manabe, Haruhiko; Ahmed, Tarek; Hiraki, Eiji; Lee, Hyun-Woo; Nakaoka, Mutsuo

    This paper presents a new circuit topology of full-bridge soft-switching PWM inverter linked DC-DC power converter composed of conventional full-bridge high frequency PWM inverter with high frequency transformer and an active quasi-resonant snubber consisting of an additional power switching device in series with DC busline and a lossless capacitor in parallel with DC busline. Under this proposed high frequency soft-switching PWM inverter linked DC-DC converter, four power switches in the full-bridge arms and DC busline series switch can achieve ZVS at turn-off commutation. By developing the advanced soft-switching PWM high frequency inverter type DC-DC converter, although the conduction power loss of DC busline series power switch increases a little, the total turn-off switching loss of full-bridge high frequency inverter power modules can be sufficiently lowered more and more in the higher frequency range of 60kHz. As a result, when the switching frequency of high frequency inverter power stage using IGBT power modules is designed so as to be more than about 10kHz, the more the switching frequency of inverter increases, the more this high frequency soft-switching DC-DC converter has remarkable advantage as for the power conversion efficiency as compared with the conventional hard-switching PWM inverter DC-DC converter. Its practical effectiveness of high power density and high performance is actually proved for TIG arc welding equipment in industry.

  3. Hot-carrier-induced linear drain current and threshold voltage degradation for thin layer silicon-on-insulator field P-channel lateral double-diffused metal-oxide-semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xin; Qiao, Ming; He, Yitao; Li, Zhaoji; Zhang, Bo, E-mail: bozhang@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China)

    2015-11-16

    Hot-carrier-induced linear drain current (I{sub dlin}) and threshold voltage (V{sub th}) degradations for the thin layer SOI field p-channel lateral double-diffused MOS (pLDMOS) are investigated. Two competition degradation mechanisms are revealed and the hot-carrier conductance modulation model is proposed. In the channel, hot-hole injection induced positive oxide trapped charge and interface trap gives rise to the V{sub th} increasing and the channel conductance (G{sub ch}) decreasing, then reduces I{sub dlin}. In the p-drift region, hot-electron injection induced negative oxide trapped charge enhances the conductance of drift doping resistance (G{sub d}), and then increases I{sub dlin}. Consequently, the eventual I{sub dlin} degradation is controlled by the competition of the two mechanisms due to conductance modulation in the both regions. Based on the model, it is explained that the measured I{sub dlin} anomalously increases while the V{sub th} is increasing with power law. The thin layer field pLDMOS exhibits more severe V{sub th} instability compared with thick SOI layer structure; as a result, it should be seriously evaluated in actual application in switching circuit.

  4. Low driving voltage and fast-response in-plane switching liquid crystal display%低驱动电压和快速响应的共面转换液晶显示器

    Institute of Scientific and Technical Information of China (English)

    王森; 孙玉宝

    2016-01-01

    In-plane switching liquid crystal displays (IPS-LCDs)are widely applied in TFT-LCD for its excellent viewing angle and outstanding ability of color reproduction.However,its development in high-end LCDs is limited by its slow response.A fast response IPS-LCD with protrusion electrode is proposed in this paper,and its optical characteristics is simulated by TechWiz software.With the pro-trusion electrode,the driving voltage of IPS-LCD is reduced by 2.3 V.Although the driving voltage is reduced,the electric field in the liquid crystal layer is changed due to the electrode on protrusion,so the rise response speed is improved.In addition,the protrusion structure reduces the effective cell gap of the LC layer,and the decay time is proportional to the square of the cell thickness,so the decay re-sponse speed is also obviously improved.The whole response speed is improved by approximately 38% in contrast with the conventional IPS-LCD.%共面转换液晶显示器(IPS-LCD)由于其优异的视角特性和色彩还原能力在 TFT-LCD 中得到了广泛应用,然而响应速度慢的缺点始终限制着其在高端液晶显示器中的发展.本文中提出一种凸起电极结构的共面转换液晶显示器,并采用 TechWiz 软件模拟了该结构的电光特性.与传统 IPS-LCD 相比,我们提出的新结构 IPS-LCD 的驱动电压降低了2.3 V.在响应时间方面,尽管驱动电压降低了,但是由于凸起电极改变液晶层中的电场状况,因此上升响应速度得到了一定提高.此外,凸起结构减小了液晶层的等效盒厚,因为下降时间正比于液晶盒厚的平方,所以下降响应速度也得到了明显提高,该结构的整体响应速度相比传统结构提高了大约38%.

  5. Wide Bandgap Extrinsic Photoconductive Switches

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, James S. [State Univ. of New York (SUNY), Plattsburgh, NY (United States); Univ. of California, Davis, CA (United States)

    2012-01-20

    Photoconductive semiconductor switches (PCSS) have been investigated since the late 1970s. Some devices have been developed that withstand tens of kilovolts and others that switch hundreds of amperes. However, no single device has been developed that can reliably withstand both high voltage and switch high current. Yet, photoconductive switches still hold the promise of reliable high voltage and high current operation with subnanosecond risetimes. Particularly since good quality, bulk, single crystal, wide bandgap semiconductor materials have recently become available. In this chapter we will review the basic operation of PCSS devices, status of PCSS devices and properties of the wide bandgap semiconductors 4H-SiC, 6H-SiC and 2H-GaN.

  6. Magnetron sputtering voltage switching power supply design based on single chip microcomputer%基于单片机的磁控溅射稳压开关电源设计

    Institute of Scientific and Technical Information of China (English)

    周志文; 马安仁

    2014-01-01

    Vacuum magnetron sputtering film coating technology has the advantages of environmental protection, reducing energy consumption, and emission reduction as compared with the traditional chemicalplating technology.Magnetron power supply is one of the most important components for this kind ofcoating devices.Magnetron regulated power supply with high power and high efficiency is studied and de -signed on the basis of high -frequency switching power supply technology .The principle of main circuitand control circuit design are introduced.A simulating model is composed with Matlab to study the parametersand the waveforms of the designed circuits.The hardware circuit and the software program aredesigned on the basis of simulation results.The adjustment and display of the output voltage and the out -put current of the power supply under different work modes are achieved with AT 89C51 single chip microcomputersystem.Practical applications confirm that the designed power supply has good constant currentcontrol effect, high reliability, work stability etc.%磁控溅射真空镀膜技术与传统的化学电镀技术相比,具有环保、降耗、减排等优点,磁控电源是这种镀膜装置的关键部件之一。该文研究和设计了以高频开关电源技术为基础的高效率、大功率磁控稳压电源。文中介绍了主电路、控制电路的原理设计,用Matlab仿真软件搭建了电路模型,并进行了仿真实验,在此基础上完成了硬件电路、软件程序设计。通过AT89 C51单片机实现了在不同工作方式下电源输出电压和电流的调节。实际应用证明该电源具有恒流控制效果好,可靠性高,工作稳定等优点。

  7. Silicon carbide DC-DC multilevel Cuk converter

    Science.gov (United States)

    Almalaq, Yasser; Alateeq, Ayoob; Matin, Mohammad

    2016-09-01

    In this paper, DC-DC multilevel cuk converter using silicon carbide (SiC) Components is presented. Cuk converter gives output voltage with negative polarity. This topology is useful for applications require high gain with limitation on duty cycle. The gain of the design can be enhanced by increasing the number of multiplier level (N). This relation between the gain and the number of levels is the major advantage of this multilevel cuk converter. In the proposed cuk converter, a single SiC MOSFET, 2N-1 SiC schottky diodes, 2N capacitors, 2 inductors, and single input voltage are used to supply a load with negative polarity. 300V input voltage, 50KHz switching frequency, and 75% duty cycle are the main parameters used in the design. The output parameters are 3KW power and -5.7 KV voltage. Because this design can be used in applications which temperature plays a critical role, the relation between increasing temperature and output voltage and power are tested. The design is simulated using LTspice software and the results are discussed.

  8. Reduction of Electric Breakdown Voltage in LC Switching Shutters / Elektriskās Caursites Sprieguma Samazināšana Šķidro Kristālu Šūnās

    Science.gov (United States)

    Mozolevskis, G.; Ozols, A.; Nitiss, E.; Linina, E.; Tokmakov, A.; Rutkis, M.

    2015-10-01

    Liquid crystal display (LCD) industry is among the most rapidly growing and innovating industries in the world. Here continuously much effort is devoted towards developing and implementing new types of LCDs for various applications. Some types of LCDs require relatively high voltages for their operation. For example, bistable displays, in which an altering field at different frequencies is used for switching from clear to scattering states and vice versa, require electric fields at around 10 V/μm for operation. When operated at such high voltages an electrical breakdown is very likely to occur in the liquid crystal (LC) cell. This has been one of the limiting factors for such displays to reach market. In the present paper, we will report on the results of electrical breakdown investigations in high-voltage LC cells. An electrical breakdown in the cell is observed when current in the liquid crystal layer is above a specific threshold value. The threshold current is determined by conductivity of the liquid crystal as well as point defects, such as dust particles in LC layer, pinholes in coatings and electrode hillocks. In order to reduce the currents flowing through the liquid crystal layer several approaches, such as electrode patterning and adding of various buffer layers in the series with LC layer, have been tested. We demonstrate that the breakdown voltages can be significantly improved by means of adding insulating thin films. Šķidro kristālu ekrānu (LCD) industrija ir viena no visstraujāk augošajām industrijām pasaulē. Daudz pūļu un resursu tiek veltīti jauna tipa LCD izstrādē dažādiem pielietojumiem. Atsevišķa tipa LCD funkcionēšanai nepieciešami augsti spriegumi. Piemēram, bistabilos LCD, kuros izkliedējošs (ieslēgts) un dzidrs (izslēgts) stāvoklis tiek iegūts ar dažādu frekvenču maiņsprieguma palīdzību, elektriskā lauka intensitāte šķidrā kristāla slānī var sasniegt pat 10 V/μm. Augstās elektriskā lauka intensit

  9. A silicon doped hafnium oxide ferroelectric p–n–p–n SOI tunneling field–effect transistor with steep subthreshold slope and high switching state current ratio

    OpenAIRE

    Saeid Marjani; Seyed Ebrahim Hosseini; Rahim Faez

    2016-01-01

    In this paper, a silicon–on–insulator (SOI) p–n–p–n tunneling field–effect transistor (TFET) with a silicon doped hafnium oxide (Si:HfO2) ferroelectric gate stack is proposed and investigated via 2D device simulation with a calibrated nonlocal band–to–band tunneling model. Utilization of Si:HfO2 instead of conventional perovskite ferroelectrics such as lead zirconium titanate (PbZrTiO3) and strontium bismuth tantalate (SrBi2Ta2O9) provides compatibility to the CMOS process as well as improved...

  10. Silicon nanowire hybrid photovoltaics

    KAUST Repository

    Garnett, Erik C.

    2010-06-01

    Silicon nanowire Schottky junction solar cells have been fabricated using n-type silicon nanowire arrays and a spin-coated conductive polymer (PEDOT). The polymer Schottky junction cells show superior surface passivation and open-circuit voltages compared to standard diffused junction cells with native oxide surfaces. External quantum efficiencies up to 88% were measured for these silicon nanowire/PEDOT solar cells further demonstrating excellent surface passivation. This process avoids high temperature processes which allows for low-cost substrates to be used. © 2010 IEEE.

  11. A novel neutral point voltage control strategy of three-level NPC converter and its single switch cycle control region analysis%新型三电平变流器中点电压控制策略及其可控区域

    Institute of Scientific and Technical Information of China (English)

    李宁; 王跃; 蒋应伟; 王兆安

    2015-01-01

    针对三电平中点钳位( neutral point clamped, NPC)变流器中点电压波动问题,分析了三电平变流器基本工作原理,提出了一种适用于任意调制策略的三电平变流器中点电压平衡策略。该策略以输出线电压满足要求为控制目标,根据中点电压的波动情况实时修正调制策略的输出开关状态。鉴于单开关周期完全可控区域的重要意义,本文分别分析了调制策略为正弦脉宽调制( si-nusoidal pulse width modulation,SPWM)策略和空间矢量脉宽调制( space vector pulse width modula-tion,SVPWM)策略时新型中点电压平衡策略的单开关周期完全可控区域。理论分析和仿真结果表明,新型中点电压平衡策略具有普遍适用、实现简单的优点,其单开关周期完全可控区域受调制策略、调制度、运行时间和功率因数的影响。%A novel neutral point ( NP ) voltage control strategy of three - level neutral point clamped ( NPC) converter was proposed to eliminate the NP voltage fluctuation under any modulation strategy. The novel NP voltage control strategy was based on the control target of output line voltage, and real-time correction of output switching states were given according to the NP voltage fluctuation. It is suitable for any modulation strategy as it only deals with the output switching states of any modulation strategy. In order to analyze the control effect of the proposed strategy, the single switch cycle control region was taken as the measurement standard and analysis of fully control region was conducted respectively when using the two most commonly used modulation strategy, sinusoidal pulse width modulation ( SPWM) strategy and space vector pulse width modulation ( SVPWM) . The theoretical analysis and simulation results show that the novel NP voltage control strategy has the advantages of wide application and easy implementation. Whereas, the fully control region of the new strategy is affected by

  12. Optical fiber crossbar switch

    Science.gov (United States)

    Kilcoyne, Michael K.; Beccue, Stephen M.; Brar, Berinder; Robinson, G.; Pedrotti, Kenneth D.; Haber, William A.

    1990-07-01

    Advances in high performance computers and signal processing systems have led to parallel system architectures. The main limitation in achieving the performance expected of these parallel systems has been the realization of an efficient means to interconnect many processors into a effective parallel system. Electronic interconnections have proved cumbersome, costly and ineffective. The Optical Fiber Crossbar Switch (OFCS) is a compact low power, multi-gigahertz bandwidth multi-channel switch which can be used in large scale computer and telecommunication applications. The switch operates in the optical domain using GaAs semiconductor lasers to transmit wideband multiple channel optical data over fiber optic cables. Recently, a 32 X 32 crossbar switching system was completed and demonstrated. Error free performance was obtained at a data bandwidth of 410 MBPS, using a silicon switch IC. The switch can be completely reconfigured in less than 50 nanoseconds under computer control. The fully populated OFCS has the capability to handle 12.8 gigabits per second (GBPS) of data while switching this data over 32 channels without the loss of a single bit during switching. GaAs IC technology has now progressed to the point that 16 X 16 GaAs based crossbar switch Ics are available which have increased the data bandwidth capability to 2.4 GBPS. The present optical interfaces are integrated GaAs transmitter drivers, GaAs lasers, and integrated GaAs optical receivers with data bandwidths exceeding 2.4 GBPS. A system using all Ill-V switching and optoelectronic components is presently under development for both NASA and DoD programs. The overall system is designed to operate at 1.3 GBPS. It is expected that these systems will find wide application in high capacity computing systems based on parallel microprocessor architecture which require high data bandwidth communication between processors. The OFCS will also have application in commercial optical telecommunication systems

  13. Exciter switch

    Science.gov (United States)

    Mcpeak, W. L.

    1975-01-01

    A new exciter switch assembly has been installed at the three DSN 64-m deep space stations. This assembly provides for switching Block III and Block IV exciters to either the high-power or 20-kW transmitters in either dual-carrier or single-carrier mode. In the dual-carrier mode, it provides for balancing the two drive signals from a single control panel located in the transmitter local control and remote control consoles. In addition to the improved switching capabilities, extensive monitoring of both the exciter switch assembly and Transmitter Subsystem is provided by the exciter switch monitor and display assemblies.

  14. Over-voltage protection system and method

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Song; Dong, Dong; Lai, Rixin

    2017-05-02

    An over-voltage protection system includes an electronic valve connected across two terminals of a circuit and an over-voltage detection circuit connected across one of the plurality of semiconductor devices for detecting an over-voltage across the circuit. The electronic valve includes a plurality of semiconductor devices connected in series. The over-voltage detection circuit includes a voltage divider circuit connected to a break-over diode in a way to provide a representative low voltage to the break-over diode and an optocoupler configured to receive a current from the break-over diode when the representative low voltage exceeds a threshold voltage of the break-over diode indicating an over-voltage condition. The representative low voltage provided to the break-over diode represents a voltage across the one semiconductor device. A plurality of self-powered gate drive circuits are connected to the plurality of semiconductor devices, wherein the plurality of self-powered gate drive circuits receive over-voltage triggering pulses from the optocoupler during the over-voltage condition and switch on the plurality of semiconductor devices to bypass the circuit.

  15. Applications, Prospects and Challenges of Silicon Carbide Junction Field Effect Transistor (SIC JFET

    Directory of Open Access Journals (Sweden)

    Frederick Ojiemhende Ehiagwina

    2016-09-01

    Full Text Available Properties of Silicon Carbide Junction Field Effect Transistor (SiC JFET such as high switching speed, low forward voltage drop and high temperature operation have attracted the interest of power electronic researchers and technologists, who for many years developed devices based on Silicon (Si.  A number of power system Engineers have made efforts to develop more robust equipment including circuits or modules with higher power density. However, it was realized that several available power semiconductor devices were approaching theoretical limits offered by Si material with respect to capability to block high voltage, provide low on-state voltage drop and switch at high frequencies. This paper presents an overview of the current applications of SiC JFET in circuits such as inverters, rectifiers and amplifiers. Other areas of application reviewed include; usage of the SiC JFET in pulse signal circuits and boost converters. Efforts directed toward mitigating the observed increase in electromagnetic interference were also discussed. It also presented some areas for further research, such as having more applications of SiC JFET in harsh, high temperature environment. More work is needed with regards to SiC JFET drivers so as to ensure stable and reliable operation, and reduction in the prices of SiC JFETs through mass production by industries.

  16. Technology of the thyristor trigger for medium voltage solid-state switch%基于晶闸管的中压固态开关触发技术

    Institute of Scientific and Technical Information of China (English)

    范彩云; 何青连; 马俊民; 李生林

    2011-01-01

    This paper expounds trigger technology for the Electronic Triggered Thyristor of solid state switch in,and points out the defects about the Electronic Triggered Thyristor of solid state switch in,and put forward the application of advantages about the Light Triggered Thyristor solid switch in%介绍晶闸管触发技术在固态开关中的应用,指出电控晶闸管的不足之处,提出光控晶闸管在固态开关中的应用优势。

  17. 275 C Downhole Switched-Mode Power Supply

    Energy Technology Data Exchange (ETDEWEB)

    Chris Hutchens; Vijay Madhuravasal

    2008-08-31

    A vee-square (V2) control based controller IC is developed for a switch mode power supply capable of operating at extreme temperature/harsh environment conditions. A buck type regulator with silicon carbide power junction field effect transistors (JFET) as power devices is used to analyze the performance of controller. Special emphases are made on the analog sub-blocks--voltage reference, operational transconductance amplifier and comparator as individual building blocks. Transformer coupled gate drives and high temperature operable magnetic cores and capacitors are identified and tested for use in the design. Conventional ceramic chip packaging of ICs combined with lead carrier type mounting of passive filter components is introduced for hybrid packaging of the complete product. The developed SMPS is anticipated to support the operation of down-hole microcontrollers and other electronics devices that require low/medium power filtered dc inputs over an operating temperature of 275 C.

  18. A compact plasmonic MOS-based 2×2 electro-optic switch

    Science.gov (United States)

    Ye, Chenran; Liu, Ke; Soref, Richard A.; Sorger, Volker J.

    2015-01-01

    We report on a three-waveguide electro-optic switch for compact photonic integrated circuits and data routing applications. The device features a plasmonic metal-oxide-semiconductor (MOS) mode for enhanced light-matter-interactions. The switching mechanism originates from a capacitor-like design where the refractive index of the active medium, indium-tin-oxide, is altered via shifting the plasma frequency due to carrier accumulation inside the waveguide-based MOS structure. This light manipulation mechanism controls the transmission direction of transverse magnetic polarized light into either a CROSS or BAR waveguide port. The extinction ratio of 18 (7) dB for the CROSS (BAR) state, respectively, is achieved via a gating voltage bias. The ultrafast broadband fJ/bit device allows for seamless integration with silicon-on-insulator platforms for low-cost manufacturing.

  19. Charge switching of donor ensembles in a semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Teichmann, Karen; Wenderoth, Martin; Loth, Sebastian; Ulbrich, Rainer G. [IV. Physikalisches Institut, Georg-August Universitaet Goettingen (Germany); Garleff, Jens K.; Wijnheijmer, A.P.; Koenraad, Paul M. [PSN, Eindhoven University of Technology (Netherlands)

    2010-07-01

    We investigated the charge state switching behaviour of interacting donors near the GaAs (110) surface, by Scanning Tunnelling Microscopy (STM). Silicon doped (n{approx}6.10{sup 18} cm{sup -3}) GaAs is cleaved in UHV to obtain a clean and atomically flat surface, directly afterwards the sample is transferred into a home build STM, working at 5 Kelvin. Using the STM tip as a movable gate the charge state of each donor can be switched from the neutral to the ionized state. The charge configuration of a single isolated donor is unambiguously determined by the position of the tip and the applied voltage. In contrast, even a two donor system with inter donor distances smaller than 5 nm shows a more complex behavior. The electrostatic interaction of two donors close together can result in ionization gaps. In certain geometrical configurations the modified electronic properties of donors close to the surface can result in bistable and time dependent charge switching behavior.

  20. Design and Fabrication of 1 × 2 Nanophotonic Switch

    Directory of Open Access Journals (Sweden)

    Asaf Shahmoon

    2010-01-01

    Full Text Available We present the design and the fabrication of a novel 1×2 nanophotonic switch. The switch is a photonic T-junction in which a gold nano particle is being positioned in the junction using the tip of an atomic force microscope (AFM. The novelty of this 1×2 switch is related to its ability to control the direction of wave that propagates along a photonic structure. The selectivity of the direction is determined by a gold nanoparticle having dimension of a few tens of nanometer. This particle can be shifted. The shift of the gold nano particle can be achieved by applying voltage or by illuminating it with a light source. The shifts of the particle, inside the air gap, direct the input beam ones to the left output of the junction and once to its right output. Three types of simulations have been done in order to realize the photonic T-junction, and they are as follows: photonic crystal structures, waveguide made out of PMMA, and a silicon waveguide.

  1. Microprocessor-controlled, programmable ramp voltage generator

    Energy Technology Data Exchange (ETDEWEB)

    Hopwood, J.

    1978-11-01

    A special-purpose voltage generator has been developed for driving the quadrupole mass filter of a residual gas analyzer. The generator is microprocessor-controlled with desired ramping parameters programmed by setting front-panel digital thumb switches. The start voltage, stop voltage, and time of each excursion are selectable. A maximum of five start-stop levels may be pre-selected for each program. The ramp voltage is 0 to 10 volts with sweep times from 0.1 to 999.99 seconds.

  2. Insights into electrical characteristics of silicon doped hafnium oxide ferroelectric thin films

    Science.gov (United States)

    Zhou, Dayu; Müller, J.; Xu, Jin; Knebel, S.; Bräuhaus, D.; Schröder, U.

    2012-02-01

    Silicon doped hafnium oxide thin films were recently discovered to exhibit ferroelectricity. In the present study, metal-ferroelectric-metal capacitors with Si:HfO2 thin films as ferroelectric material and TiN as electrodes have been characterized with respect to capacitance and current density as functions of temperature and applied voltage. Polarity asymmetry of the frequency dependent coercive field was explained by interfacial effects. No ferroelectric-paraelectric phase transition was observed at temperatures up to 478 K. Clear distinctions between current evolutions with or without polarization switching were correlated to the time competition between the measurement and the response of relaxation mechanisms.

  3. High Voltage Pulse Testing Survey.

    Science.gov (United States)

    1985-10-01

    Cryogenic 23 E. Liquids 26 F. Solids 28 1. Polyethylene 28 2. Cross-Linked Polyethylene ( XLPE ) 29 3. Polyimide and Polyvenylchloride (PVC) 31 VI Benefits 35 A...Strength of XLPE Cables 29 vii * 4" I PROGRAM OBJECTIVES The Pulse Test Survey summarizes government, industry, and technical reports on high voltage pulse...system of silicone oil on a XLPE (cross-linked polyethylene) spacer tends to lower the impulse breakdown by approximately 10 percent. The negative impulse

  4. Energy losses in switches

    Energy Technology Data Exchange (ETDEWEB)

    Martin, T.H.; Seamen, J.F.; Jobe, D.O.

    1993-07-01

    The authors experiments show energy losses between 2 and 10 times that of the resistive time predictions. The experiments used hydrogen, helium, air, nitrogen, SF{sub 6} polyethylene, and water for the switching dielectric. Previously underestimated switch losses have caused over predicting the accelerator outputs. Accurate estimation of these losses is now necessary for new high-efficiency pulsed power devices where the switching losses constitute the major portion of the total energy loss. They found that the switch energy losses scale as (V{sub peak}I{sub peak}){sup 1.1846}. When using this scaling, the energy losses in any of the tested dielectrics are almost the same. This relationship is valid for several orders of magnitude and suggested a theoretical basis for these results. Currents up to .65 MA, with voltages to 3 MV were applied to various gaps during these experiments. The authors data and the developed theory indicates that the switch power loss continues for a much longer time than the resistive time, with peak power loss generally occurring at peak current in a ranging discharge instead of the early current time. All of the experiments were circuit code modeled after developing a new switch loss version based on the theory. The circuit code predicts switch energy loss and peak currents as a function of time. During analysis of the data they noticed slight constant offsets between the theory and data that depended on the dielectric. They modified the plasma conductivity for each tested dielectric to lessen this offset.

  5. The Liquid Metal Plasma Valve Closing Switch,

    Science.gov (United States)

    1976-01-01

    Table 1. Switch Specification s Closing HVDC LMPV Switch Converter LMPV Circuit Parameter...Parameters Rating Breaker Rating Peak Voltage 50-200 kV 150 kV nominal 30 kV Pulse Width 20-50 1isec 6 msec 20 msec Peak Current 8-4 kA 1.8 kA nominal

  6. Characterisation of the VELO High Voltage System

    CERN Document Server

    Rakotomiaramanana, B; Eklund, L

    2008-01-01

    The high voltage system supplies the bias voltage to the 88 silicon sensors which comprise the LHCb Vertex Locator (VELO). This note describes the results of the tests which have been performed on the hardware of the high voltage system of the VELO. Each individual test detailed in this note corresponds to a specific requirement of the system. These requirements arise primarily from ensuring the safety of the silicon sensors and the quality of the data taken from the VELO modules. The tests performed are in four categories: normal operation of the high voltage system; vercation of its stability under operation; discussion of its behaviour in failure modes; and details of operation at low voltage. Noteworthy issues, identified through the tests, include the behaviour of the high voltage modules at voltages below 9V, the current limit that can be applied during ramping of the voltage, and the speed with which the voltage is cut during failures of the system. The results of these tests provide high confidence th...

  7. Characterisation of the VELO High Voltage System

    CERN Document Server

    Rakotomiaramanana, B; Parkes, C; Eklund, L

    2008-01-01

    The high voltage system supplies the bias voltage to the 88 silicon sensors which comprise the LHCb Vertex Locator (VELO). This note describes the results of the tests which have been performed on the hardware of the high voltage system of the VELO. Each individual test detailed in this note corresponds to a specific requirement of the system. These requirements arise primarily from ensuring the safety of the silicon sensors and the quality of the data taken from the VELO modules. The tests performed are in four categories: normal operation of the high voltage system; verification of its stability under operation; discussion of its behaviour in failure modes; and details of operation at low voltage. Noteworthy issues, identified through the tests, include the behaviour of the high voltage modules at voltages below 9V, the current limit that can be applied during ramping of the voltage, and the speed with which the voltage is cut during failures of the system. The results of these tests provide high confidence...

  8. The effect of "on/off" molecular switching on the photophysical and photochemical properties of axially calixarene substituted activatable silicon(iv)phthalocyanine photosensitizers.

    Science.gov (United States)

    Güngör, Ömer; Altınbaş Özpınar, Gül; Durmuş, Mahmut; Ahsen, Vefa

    2016-05-04

    Silicon(iv) phthalocyanines ( and ) bearing two calixarene groups as axial ligands were synthesized. Surprisingly, both phthalocyanines were obtained as two different isomers ( and ) depending on the distance between calixarene benzene groups and the phthalocyanine ring. DFT and TD-DFT computations were performed to model plausible structures of these isomers and to simulate electronic absorption spectra. These isomers converted into each other depending on the polarity of the used solvent, temperature and light irradiation. The photophysical and photochemical properties of each isomer were investigated in dimethylsulfoxide (DMSO) for the determination of photodynamic therapy (PDT) activities of these compounds. The more blue-shifted isomers ( and ) showed higher fluorescence quantum yields and singlet oxygen generation compared to more red-shifted counterparts ( and ). This behavior is extremely important for developing activatable photosensitizers for cancer treatment by PDT. Although these photosensitizers produce lower singlet oxygen in normal cells, they produce higher singlet oxygen (six times higher for ) in cancer cells since these photosensitizers converted to more blue-shifted isomers by using light irradiation.

  9. SOI-Based High-Voltage, High-Temperature Integrated Circuit Gate Driver for SiC-Based Power FETs

    Energy Technology Data Exchange (ETDEWEB)

    Huque, Mohammad A [ORNL; Tolbert, Leon M [ORNL; Blalock, Benjamin [University of Tennessee, Knoxville (UTK); Islam, Syed K [University of Tennessee, Knoxville (UTK)

    2010-01-01

    Silicon carbide (SiC)-based field effect transistors (FETs) are gaining popularity as switching elements in power electronic circuits designed for high-temperature environments like hybrid electric vehicle, aircraft, well logging, geothermal power generation etc. Like any other power switches, SiC-based power devices also need gate driver circuits to interface them with the logic units. The placement of the gate driver circuit next to the power switch is optimal for minimizing system complexity. Successful operation of the gate driver circuit in a harsh environment, especially with minimal or no heat sink and without liquid cooling, can increase the power-to-volume ratio as well as the power-to-weight ratio for power conversion modules such as a DC-DC converter, inverter etc. A silicon-on-insulator (SOI)-based high-voltage, high-temperature integrated circuit (IC) gate driver for SiC power FETs has been designed and fabricated using a commercially available 0.8-m, 2-poly and 3-metal bipolar-complementary metal oxide semiconductor (CMOS)-double diffused metal oxide semiconductor (DMOS) process. The prototype circuit-s maximum gate drive supply can be 40-V with peak 2.3-A sourcing/sinking current driving capability. Owing to the wide driving range, this gate driver IC can be used to drive a wide variety of SiC FET switches (both normally OFF metal oxide semiconductor field effect transistor (MOSFET) and normally ON junction field effect transistor (JFET)). The switching frequency is 20-kHz and the duty cycle can be varied from 0 to 100-. The circuit has been successfully tested with SiC power MOSFETs and JFETs without any heat sink and cooling mechanism. During these tests, SiC switches were kept at room temperature and ambient temperature of the driver circuit was increased to 200-C. The circuit underwent numerous temperature cycles with negligible performance degradation.

  10. Picosecond High Pressure Gas Switch experiment

    Energy Technology Data Exchange (ETDEWEB)

    Cravey, W.R.; Freytag, E.K.; Goerz, D.A.; Poulsen, P.; Pincosy, P.A.

    1993-08-01

    A high Pressure Gas Switch has been developed and tested at LLNL. Risetimes on the order of 200 picoseconds have been observed at 1 kHz prf and 1 atmosphere pressures. Calculations show that switching closure times on the order of tens of picoseconds can be achieved at higher pressures and electric fields. A voltage hold-off of 1 MV/cm has been measured at 10 atmospheres and several MV/cm appears possible with the HPGS. With such high electric field levels, energy storage of tens of Joules in a reasonably sized package is achievable. Initial HPGS performance has been characterized using the WASP pulse generator at LLNL. A detailed description of the switch used for initial testing is given. Switch recovery times of 1-ms have been measured at 1 atmosphere. Data on the switching uniformity, voltage hold-off recovery, and pulse repeatability, is presented. In addition, a physics switch model is described and results are compared with experimental data. Modifications made to the WASP HV pulser in order to drive the HPGS will also be discussed. Recovery times of less than 1 ms were recorded without gas flow in the switch chambers. Low pressure synthetic air was used as the switch dielectric. Longer recovery times were required when it was necessary to over-voltage the switch.

  11. Triple voltage dc-to-dc converter and method

    Science.gov (United States)

    Su, Gui-Jia

    2008-08-05

    A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.

  12. Detail study of SiC MOSFET switching characteristics

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig

    2014-01-01

    This paper makes detail study of the latest SiC MOSFETs switching characteristics in relation to gate driver maximum current, gate resistance, common source inductance and parasitic switching loop inductance. The switching performance of SiC MOSFETs in terms of turn on and turn off voltage...... and current are presented. Switching losses analysis is made according to the experiment results. The switching characteristics study and switching losses analysis could give some guidelines of gate driver IC and gate resistance selection, switching losses estimation and circuit design of SiC MOSFETs....

  13. 一种避免低压隔离变压器合闸涌流的新型实用方法%The practical method to avoid switching inrush current of low-voltage isolation transformer

    Institute of Scientific and Technical Information of China (English)

    赵忠云; 田贵书

    2016-01-01

    介绍了变压器空载合闸励磁涌流产生机理,详细分析了利用软启动器空载合闸及分闸隔离变压器时避免合闸涌流及操作过电压的原理、方法,验证了该方法安全可靠、成本低、安装方便,值得推广。%The generating mechanism of no-load switching inrush current in transformer is introduced. This paper makes in-depth analysis of using soft starter with no-load closing and opening isolation transformer to avoid switching inrush current, principle and method of switching surge. It shows that the method has characteristics of safety and reliability, low cost and easy installation, which is worth promoting.

  14. Silicone elastomers with aromatic voltage stabilizers

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Skov, Anne Ladegaard

    breakdown strength, the storage modulus and the loss modulus of the elastomer were investigated, as well as the excitation energy from the collision between electron carriers and benzene rings in PDMS-PPMS copolymer was measured by UV-vis spectroscopy. The developed elastomers were inherently soft...

  15. Silicone elastomers with aromatic voltage stabilizers

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Skov, Anne Ladegaard

    , as well as the excitation energy from the collision between electron carriers and benzene rings in PDMS-PPMS copolymer was measured by UV-vis spectroscopy. The developed elastomers were inherently soft with enhanced electrical breakdown strength due to delocalized pi-electrons of aromatic rings attached...

  16. Parametric scaling study of a magnetically insulated thermionic vacuum switch

    Energy Technology Data Exchange (ETDEWEB)

    Vanderberg, B.H.; Eninger, J.E. [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Industrial Electrotechnology

    1996-02-01

    A parametric scaling study is performed on MINOS (Magnetically INsulated Opening Switch), a novel fast ({approximately}100 ns) high-power opening switch concept based on a magnetically insulated thermionic vacuum diode. Principal scaling parameters are the switch dimensions, voltage, current, applied magnetic field, and switching time. The scaling range of interest covers voltages up to 100 kV and currents of several kA. Fundamental scaling properties are derived from models of space-charge flow and magnetic cutoff. The scaling is completed with empirical results from the experimental MX-1 switch operated in an inductive storage pulsed power generator. Results are presented in diagrams showing voltage, current, power, and efficiency relationships and their limitations. The scaling is illustrated by the design of a megawatt average power opening switch for pulsed power applications. Trade-offs in the engineering of this type of switch are discussed.

  17. Low voltage arc formation in railguns

    Science.gov (United States)

    Hawke, Ronald S.

    1987-01-01

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

  18. Development of high-voltage pulse generator with variable amplitude and duration

    Science.gov (United States)

    Upadhyay, J.; Sharma, M. L.; Ahuja, Aakash B.; Navathe, C. P.

    2014-06-01

    A high voltage pulse generator with variable amplitude (100-3000 V) and duration (100-2000 μs) has been designed and developed. The variable duration pulse has been generated by adopting a simple and novel technique of varying the turn off delay time of a high voltage Metal Oxide Semiconductor Field Effect Transistor (MOSFET) based switch by varying external gate resistance. The pulse amplitude is made variable by adjusting biasing supply of the high voltage switch. The high voltage switch has been developed using a MOSFET based stack of 3 kV rating with switching time of 7 ns.

  19. A Single Switch Dual Output Non-Isolated Boost Converter

    DEFF Research Database (Denmark)

    Klimczak, Pawel; Munk-Nielsen, Stig

    2008-01-01

    very simple dual output non-isolated boost converter is presented. Single active switch is used to control both, positive and negative output voltages. The converter is desired to boost unregulated low input voltage 25-50 Vdc to regulated high voltage ±400 Vdc in dual dc-link. In this paper proposed...

  20. Evaluation of Switch Currents in Nine-Switch Energy Conversion Systems

    DEFF Research Database (Denmark)

    Loh, Poh Chiang; Bahman, Amir Sajjad; Qin, Zian;

    2013-01-01

    Converters with reduced switch counts usually face some performance tradeoffs, which make them suitable for some applications but not others. The same applies to the nine-switch converter, which is a reduced-switch version of the back-to-back twelve-switch converter. The nine-switch converter has...... since been shown to experience a higher voltage stress, which can be lowered in some cases. A corresponding evaluation of its current stress is however lacking, and is hence addressed now by computing its switch currents when used for ac-ac, ac-dc, dc-ac and dc-dc energy conversions. Relevant...... expressions, application requirements and simulation results are presented for identifying cases, where the nine-switch converter can have an improvement in performance despite its reduced switch count....

  1. The Control Unit of a Single Phase Voltage Regulator

    CERN Document Server

    Colak, Ilknur

    2010-01-01

    Supplying regulated voltage to critical loads is an important topic for several years. This paper presents a single-phase electronic voltage regulator based on high frequency switching of an isolated transformer where primary side voltage is controlled by two full-bridge converters sharing a common DC bus and operating at 50Hz and 20kHz switching frequencies. This allows 50Hz induced voltage on the primary side of the transformer, regulated by high frequency switching. Depending on the input voltage, voltage at the secondary side of the transformer add to (boost mode) or subtract (buck mode) from the supply voltage, therefore, maintaining a regulated voltage value across the load. The regulator is controlled by a digital controller allowing fast dynamic response. A 5kVA single-phase voltage regulator is realized to verify the operation of the proposed algorithm. The experimental results show that regulator maintains constant voltage across the load both in step-up (low supply voltage) and step-down (high supp...

  2. Copper pillar and memory characteristics using Al2O3 switching material for 3D architecture.

    Science.gov (United States)

    Maikap, Siddheswar; Panja, Rajeswar; Jana, Debanjan

    2014-01-01

    A novel idea by using copper (Cu) pillar is proposed in this study, which can replace the through-silicon-vias (TSV) technique in future three-dimensional (3D) architecture. The Cu pillar formation under external bias in an Al/Cu/Al2O3/TiN structure is simple and low cost. The Cu pillar is formed in the Al2O3 film under a small operation voltage of 70 mA is obtained. More than 100 devices have shown tight distribution of the Cu pillars in Al2O3 film for high current compliance (CC) of 70 mA. Robust read pulse endurances of >10(6) cycles are observed with read voltages of -1, 1, and 4 V. However, read endurance is failed with read voltages of -1.5, -2, and -4 V. By decreasing negative read voltage, the read endurance is getting worst, which is owing to ruptured Cu pillar. Surface roughness and TiO x N y on TiN bottom electrode are observed by atomic force microscope and transmission electron microscope, respectively. The Al/Cu/Al2O3/TiN memory device shows good bipolar resistive switching behavior at a CC of 500 μA under small operating voltage of ±1 V and good data retention characteristics of >10(3) s with acceptable resistance ratio of >10 is also obtained. This suggests that high-current operation will help to form Cu pillar and lower-current operation will have bipolar resistive switching memory. Therefore, this new Cu/Al2O3/TiN structure will be benefited for 3D architecture in the future.

  3. Manufacturing Practices for Silicon-Based Power Diode in Fast Recovery Applications

    Directory of Open Access Journals (Sweden)

    N. Harihara Krishnan

    2011-01-01

    Full Text Available This paper reports a fast recovery semiconductor diode that was developed for use in high power applications. The diode constructed in disc-type ceramic package with a peak-inverse voltage rating of 2800 V and current rating of 710 A was fabricated using float-zone (FZ silicon wafer as the starting raw material. Alternate processes viz. gold diffusion, gamma irradiation and electron irradiation were explored for control of carrier lifetime required to tune the switching response of the diode to the desired value of 8 μs. The paper compares the results of these alternate processes. The diodes were fabricated and tested for forward conduction, reverse blocking and switching characteristics. The measured values were observed to be comparable with the design requirements. The paper presents an overview of the design, manufacturing and testing practices adopted to meet the desired diode characteristics and ratings.

  4. Nucleosome switches.

    Science.gov (United States)

    Schwab, David J; Bruinsma, Robijn F; Rudnick, Joseph; Widom, Jonathan

    2008-06-06

    We present a statistical-mechanical model for the positioning of nucleosomes along genomic DNA molecules as a function of the strength of the binding potential and the chemical potential of the nucleosomes. We show that a significant section of the DNA is composed of two-level nucleosome switching regions where the nucleosome distribution undergoes a localized, first-order transition. The location of the nucleosome switches shows a strong correlation with the location of gene-regulation regions.

  5. Interface circuit with adjustable bias voltage enabling maximum power point tracking of capacitive energy harvesting devices

    Science.gov (United States)

    Wei, J.; Lefeuvre, E.; Mathias, H.; Costa, F.

    2016-12-01

    The operation analysis of a new interface circuit for electrostatic vibration energy harvesting with adjustable bias voltage is carried out in this paper. Two configurations determined by the open or closed states of an electronic switch are examined. The increase of the voltage across a biasing capacitor, occurring when the switch is open, is proved theoretically and experimentally. With the decrease of this biasing voltage which occurs naturally when the switch is closed due to imperfections of the circuit, the bias voltage can be maintained close to a target value by appropriate ON and OFF control of the switch. As the energy converted by the variable capacitor on each cycle depends on the bias voltage, this energy can be therefore accurately controlled. This feature opens up promising perspectives for optimization the power harvested by electrostatic devices. Simulation results with and without electromechanical coupling effect are presented. In experimental tests, a simple switch control enabling to stabilize the bias voltage is described.

  6. Sequential shock induced switch tests for Eglin Air Force Base

    Energy Technology Data Exchange (ETDEWEB)

    Cech, R.D.

    1994-08-11

    Tests were performed at EG&G Mound Applied Technologies to investigate the effect of using the tangential shock wave from detonating Extex explosive to cause shock conduction of a Kapton dielectric. Two voltages (600 and 4000) were switched from a 600 pF capacitor. Timing between four shock switches and four pin switches was found and compared during a single detonation event. Electrical conduction was observed between shock switches and the current paths were found.

  7. USING PHOTO-INDUCED OPEN-CIRCUIT VOLTAGE

    African Journals Online (AJOL)

    open-circuit voltage decay, silicon photovoltaic solar cells. ..... cells in series configuration encapsulated on a ceramic base with glass cover and has an effective .... silicon solar cells and should be used parallel to the common performance test ...

  8. Understanding of self-terminating pulse generation using silicon controlled rectifier and RC load

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Chris, E-mail: chrischang81@gmail.com; Karunasiri, Gamani, E-mail: karunasiri@nps.edu [Department of Physics, Naval Postgraduate School, Monterey, CA 93943 (United States); Alves, Fabio, E-mail: falves@alionscience.com [Alion Science and Technology at NPS, Monterey, CA 93943 (United States)

    2016-01-15

    Recently a silicon controlled rectifier (SCR)-based circuit that generates self-terminating voltage pulses was employed for the detection of light and ionizing radiation in pulse mode. The circuit consisted of a SCR connected in series with a RC load and DC bias. In this paper, we report the investigation of the physics underlying the pulsing mechanism of the SCR-based. It was found that during the switching of SCR, the voltage across the capacitor increased beyond that of the DC bias, thus generating a reverse current in the circuit, which helped to turn the SCR off. The pulsing was found to be sustainable only for a specific range of RC values depending on the SCR’s intrinsic turn-on/off times. The findings of this work will help to design optimum SCR based circuits for pulse mode detection of light and ionizing radiation without external amplification circuitry.

  9. Understanding of self-terminating pulse generation using silicon controlled rectifier and RC load

    Science.gov (United States)

    Chang, Chris; Alves, Fabio; Karunasiri, Gamani

    2016-01-01

    Recently a silicon controlled rectifier (SCR)-based circuit that generates self-terminating voltage pulses was employed for the detection of light and ionizing radiation in pulse mode. The circuit consisted of a SCR connected in series with a RC load and DC bias. In this paper, we report the investigation of the physics underlying the pulsing mechanism of the SCR-based. It was found that during the switching of SCR, the voltage across the capacitor increased beyond that of the DC bias, thus generating a reverse current in the circuit, which helped to turn the SCR off. The pulsing was found to be sustainable only for a specific range of RC values depending on the SCR's intrinsic turn-on/off times. The findings of this work will help to design optimum SCR based circuits for pulse mode detection of light and ionizing radiation without external amplification circuitry.

  10. CONTROL OF BOUNCING IN RF MEMS SWITCHES USING DOUBLE ELECTRODE

    KAUST Repository

    Abdul Rahim, Farhan

    2014-05-01

    MEMS based mechanical switches are seen to be the likely replacements for CMOS based switches due to the several advantages that these mechanical switches have over CMOS switches. Mechanical switches can be used in systems under extreme conditions and also provide more reliability and cause less power loss. A major problem with mechanical switches is bouncing. Bouncing is an undesirable characteristic which increases the switching time and causes damage to the switch structure affecting the overall switch life. This thesis proposes a new switch design that may be used to mitigate bouncing by using two voltage sources using a double electrode configuration. The effect of many switch’s tunable parameters is also discussed and an effective tuning technique is also provided. The results are compared to the current control schemes in literature and show that the double electrode scheme is a viable control option.

  11. Silicon photonics for multicore fiber communication

    DEFF Research Database (Denmark)

    Ding, Yunhong; Kamchevska, Valerija; Dalgaard, Kjeld

    2016-01-01

    We review our recent work on silicon photonics for multicore fiber communication, including multicore fiber fan-in/fan-out, multicore fiber switches towards reconfigurable optical add/drop multiplexers. We also present multicore fiber based quantum communication using silicon devices....

  12. Grid Filter Design for a Multi-Megawatt Medium-Voltage Voltage Source Inverter

    DEFF Research Database (Denmark)

    Rockhill, A.A.; Liserre, Marco; Teodorescu, Remus

    2011-01-01

    This paper describes the design procedure and performance of an LCL grid filter for a medium-voltage neutral point clamped (NPC) converter to be adopted for a multimegawatt wind turbine. The unique filter design challenges in this application are driven by a combination of the medium voltage......-megawatt filter connecting a medium-voltage converter switching at low frequency to the electric grid. This paper demonstrates a frequency domain model based approach to determine the optimum filter parameters that provide the necessary performance under all operating conditions given the necessary design...... converter, a limited allowable switching frequency, component physical size and weight concerns, and the stringent limits for allowable injected current harmonics. Traditional design procedures of grid filters for lower power and higher switching frequency converters are not valid for a multi...

  13. Grid Filter Design for a Multi-Megawatt Medium-Voltage Voltage Source Inverter

    DEFF Research Database (Denmark)

    Rockhill, A.A.; Liserre, Marco; Teodorescu, Remus

    2011-01-01

    converter, a limited allowable switching frequency, component physical size and weight concerns, and the stringent limits for allowable injected current harmonics. Traditional design procedures of grid filters for lower power and higher switching frequency converters are not valid for a multi......This paper describes the design procedure and performance of an LCL grid filter for a medium-voltage neutral point clamped (NPC) converter to be adopted for a multimegawatt wind turbine. The unique filter design challenges in this application are driven by a combination of the medium voltage......-megawatt filter connecting a medium-voltage converter switching at low frequency to the electric grid. This paper demonstrates a frequency domain model based approach to determine the optimum filter parameters that provide the necessary performance under all operating conditions given the necessary design...

  14. Switching Characteristics of Ferroelectric Transistor Inverters

    Science.gov (United States)

    Laws, Crystal; Mitchell, Coey; MacLeod, Todd C.; Ho, Fat D.

    2010-01-01

    This paper presents the switching characteristics of an inverter circuit using a ferroelectric field effect transistor, FeFET. The propagation delay time characteristics, phl and plh are presented along with the output voltage rise and fall times, rise and fall. The propagation delay is the time-delay between the V50% transitions of the input and output voltages. The rise and fall times are the times required for the output voltages to transition between the voltage levels V10% and V90%. Comparisons are made between the MOSFET inverter and the ferroelectric transistor inverter.

  15. Research of an electromagnetically actuated spark gap switch.

    Science.gov (United States)

    Zhang, Tianyang; Chen, Dongqun; Liu, Jinliang; Wang, Yuwei; Qiu, Yongfeng

    2013-11-01

    As an important part of pulsed power systems, high-voltage and high-current triggered spark gap switch and its trigger system are expected to achieve a compact structure. In this paper, a high-voltage, high-current, and compact electromagnetically actuated spark gap switch is put forward, and it can be applied as a part of an intense electron-beam accelerator (IEBA). A 24 V DC power supply is used to trigger the switch. The characteristics of the switch were measured for N2 when the gas pressure is 0.10-0.30 MPa. The experimental results showed that the voltage/pressure (V/p) curve of the switch was linear relationship. The operating ranges of the switch were 21%-96%, 21%-95%, 21%-95%, 19%-95%, 17%-95%, and 16%-96% of the switch's self-breakdown voltage when the gas pressures were 0.10, 0.14, 0.18, 0.22, 0.26, and 0.30 MPa, respectively. The switch and its trigger system worked steadily and reliably with a peak voltage of 30 kV, a peak current of 60 kA in the IEBA when the pressure of N2 in the switch was 0.30 MPa.

  16. High voltage systems (tube-type microwave)/low voltage system (solid-state microwave) power distribution

    Science.gov (United States)

    Nussberger, A. A.; Woodcock, G. R.

    1980-01-01

    SPS satellite power distribution systems are described. The reference Satellite Power System (SPS) concept utilizes high-voltage klystrons to convert the onboard satellite power from dc to RF for transmission to the ground receiving station. The solar array generates this required high voltage and the power is delivered to the klystrons through a power distribution subsystem. An array switching of solar cell submodules is used to maintain bus voltage regulation. Individual klystron dc voltage conversion is performed by centralized converters. The on-board data processing system performs the necessary switching of submodules to maintain voltage regulation. Electrical power output from the solar panels is fed via switch gears into feeder buses and then into main distribution buses to the antenna. Power also is distributed to batteries so that critical functions can be provided through solar eclipses.

  17. Zinc Oxide Surface Flashover Triggering of Pseudospark Switch

    Institute of Scientific and Technical Information of China (English)

    谢建民; 邱毓昌

    2003-01-01

    Accurate and reliable triggering is one of the most important issues with high powerpseudospark switch, because it not only has an impact on the design of discharge chamber ofswitch, but also has an influence on the dynamic range of operation voltage, repetition frequenciesand lifetime of switch. The unique feature of pseudospark switch is its hollow cathode geometry.The hollow cathode effect produced by the hollow cathode provides the protection of the switchfor the triggering unit from erosion by high discharge plasma. In this paper, a zinc oxide (ZnO)surface flashover triggering is presented. This trigger unit possesses an excellent time delay (80 ns~ 360 ns) and jitter (20 ns ~ 50 ns) at the switch voltage of 30 kV ~ 2 kV. The emitted plasmaelectron density is high enough to trigger switch reliably down to switch voltage of 440 V.

  18. Protection of Low Voltage CIGRE distribution Network

    DEFF Research Database (Denmark)

    Mustafa, Ghullam; Bak-Jensen, Birgitte; Bak, Claus Leth

    2013-01-01

    the inverters used for Photovoltaic (PV) and battery applications. The disconnection of the PV solar panels when in island mode is made by proposing switch dis-connecting devices. ABB is currently using these kinds of disconnection devices for the purpose of protecting solar panels against over voltages...

  19. Compact model for switching characteristics of graphene field effect transistor

    Science.gov (United States)

    Sreenath, R.; Bala Tripura Sundari, B.

    2016-04-01

    The scaling of CMOS transistors has resulted in intensified short channel effects, indicating that CMOS has reached its physical limits. Alternate non silicon based materials namely carbon based graphene, carbon nanotubes are being explored for usability as channel and interconnect material due to their established higher mobility and robustness. This paper presents a drift-diffusion based circuit simulatable Verilog-A compact model of graphene field effect transistor (GFET) for channel length of 100nm.The focus is on the development of simulatable device model in Verilog A based on intrinsic parameters and obtain the current, high cutoff frequency and use the model into circuit level simulations to realize an inverter and a 3-stage ring oscillator using Synopsys HSPICE. The applications are so chosen that their switching characteristics enable the determination of the RF frequency ranges of operation that the model can achieve when used in digital applications and also to compare its performance with existing CMOS model. The GFET's switching characteristics and power consumption were found to be better than similarly sized CMOS operating at same range of voltages. The basic frequency of operation in the circuit is of significant importance so as to use the model in other applications at RF and in future for millimeter wave applications. The frequency of operation at circuit level is found to be 1.1GHz at 100nm which is far higher than the existing frequency of 245 MHz reported at 500nm using AlN.

  20. Molecular Rotors as Switches

    Directory of Open Access Journals (Sweden)

    Kang L. Wang

    2012-08-01

    Full Text Available The use of a functional molecular unit acting as a state variable provides an attractive alternative for the next generations of nanoscale electronics. It may help overcome the limits of conventional MOSFETd due to their potential scalability, low-cost, low variability, and highly integratable characteristics as well as the capability to exploit bottom-up self-assembly processes. This bottom-up construction and the operation of nanoscale machines/devices, in which the molecular motion can be controlled to perform functions, have been studied for their functionalities. Being triggered by external stimuli such as light, electricity or chemical reagents, these devices have shown various functions including those of diodes, rectifiers, memories, resonant tunnel junctions and single settable molecular switches that can be electronically configured for logic gates. Molecule-specific electronic switching has also been reported for several of these device structures, including nanopores containing oligo(phenylene ethynylene monolayers, and planar junctions incorporating rotaxane and catenane monolayers for the construction and operation of complex molecular machines. A specific electrically driven surface mounted molecular rotor is described in detail in this review. The rotor is comprised of a monolayer of redox-active ligated copper compounds sandwiched between a gold electrode and a highly-doped P+ Si. This electrically driven sandwich-type monolayer molecular rotor device showed an on/off ratio of approximately 104, a read window of about 2.5 V, and a retention time of greater than 104 s. The rotation speed of this type of molecular rotor has been reported to be in the picosecond timescale, which provides a potential of high switching speed applications. Current-voltage spectroscopy (I-V revealed a temperature-dependent negative differential resistance (NDR associated with the device. The analysis of the device