WorldWideScience

Sample records for voltage switching ebs

  1. 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.

  2. 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...

  3. 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....

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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....

  17. 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.

  18. The Electron Beam Semiconductor (EBS) amplifier

    Science.gov (United States)

    True, R. M.; Baxendale, J. F.

    1980-07-01

    The Electron Beam Semiconductor (EBS) concept has existed for three decades; but only within the last decade has an active, well-defined program been underway to develop devices that can operate as high-power radio frequency(RF) amplifiers, fast risetime switches, and current and voltage pulse amplifiers. This report discusses the test procedures, data and results of reliability testing of RF and video pulse EBS amplifiers at Electronics Research and Development Command (ERADCOM), Fort Monmouth, New Jersey. Also, the experimental analysis of the series connected diode EBS device is described in detail. Finally, the report concludes with a discussion of the state-of-the-art of EBS and future trends of the technology.

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  3. 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...

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  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. 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.

  3. 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.

  4. 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)

  5. 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.

  6. 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...

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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....

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  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. 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.

  2. 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

  3. 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....

  4. 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...

  5. 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.

  6. 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.

  7. 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.)

  8. 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.

  9. 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.

  10. 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...

  11. 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.

  12. 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…

  13. 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.

  14. 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...

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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)

  20. 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.

  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. 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.

  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. 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.

  5. 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.

  6. 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...

  7. 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).

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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)

  17. 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...

  18. 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.

  19. 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.

  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. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. EBS Radionuclide Transport Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    R. Schreiner

    2001-06-27

    The purpose of this work is to develop the Engineered Barrier System (EBS) radionuclide transport abstraction model, as directed by a written development plan (CRWMS M&O 1999a). This abstraction is the conceptual model that will be used to determine the rate of release of radionuclides from the EBS to the unsaturated zone (UZ) in the total system performance assessment-license application (TSPA-LA). In particular, this model will be used to quantify the time-dependent radionuclide releases from a failed waste package (WP) and their subsequent transport through the EBS to the emplacement drift wall/UZ interface. The development of this conceptual model will allow Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department to provide a more detailed and complete EBS flow and transport abstraction. The results from this conceptual model will allow PA0 to address portions of the key technical issues (KTIs) presented in three NRC Issue Resolution Status Reports (IRSRs): (1) the Evolution of the Near-Field Environment (ENFE), Revision 2 (NRC 1999a), (2) the Container Life and Source Term (CLST), Revision 2 (NRC 1999b), and (3) the Thermal Effects on Flow (TEF), Revision 1 (NRC 1998). The conceptual model for flow and transport in the EBS will be referred to as the ''EBS RT Abstraction'' in this analysis/modeling report (AMR). The scope of this abstraction and report is limited to flow and transport processes. More specifically, this AMR does not discuss elements of the TSPA-SR and TSPA-LA that relate to the EBS but are discussed in other AMRs. These elements include corrosion processes, radionuclide solubility limits, waste form dissolution rates and concentrations of colloidal particles that are generally represented as boundary conditions or input parameters for the EBS RT Abstraction. In effect, this AMR provides the algorithms for transporting radionuclides using the flow geometry and radionuclide concentrations

  12. 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%.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. EBS Radionuclide Transport Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    J. Prouty

    2006-07-14

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport

  6. 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.

  7. 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).

  8. 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

  9. 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.

  10. 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...

  11. 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...

  12. 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.

  13. 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.

  14. EBS Radionuclide Transport Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    J.D. Schreiber

    2005-08-25

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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...

  20. 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,

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Application of EB in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Sunaga, Hiromi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2003-02-01

    Radiation processing using electron beam (EB) facilities other than gamma-ray facilities in Japan is introduced. After briefly presented the features of EB compared with gamma ray, present status of EB application is described. Polymerized materials for use of wire, cable, radial tire, heat shrinkable tube, foam polyethylene, PTFE, battery separator, and adsorbent material are known to be resulting from cross-linking, decomposition, and graft polymerization reactions. Environmental preservation includes electron flue gas treatment in the coal- or oil-fired power plants, research for volatile organic compounds (VOC) and dioxins, as well as wastewater and sludge treatment. Finally activity of JAERI in the related fields is overviewed with the authors prospects for utilization of low energy EB with low cost for surface treatment and functional materials. (S. Ohno)

  10. 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)

  11. 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.

  12. 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.

  13. 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)

  14. 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。

  15. 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.

  16. 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.

  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. Experimental Research Of Charged Particles Streams, Emitted From Area Of Eb Acting On Material, In Order To Estimate The Possibilities Of Using Them To Eb Welding Control

    CERN Document Server

    Olszewska, K

    2001-01-01

    The basic parameters of electron beam (EB) welding process are position and dimensions of so called EB active zone. Wrong position of active zone make impossible to obtain desirable shape of a weld and may cause various defects of a weld. Relatively reach source of information about EB welding process are charged particles emitted from the area of EB acting on material. The measurements of various types of signals for the three largest groups of charged particles: back-scattered electrons, really secondary electrons and ions were carried out. It was estimated that practically none of them could be used directly in procedures of EB active zone position control. It is result of ambiguous of information, they contain and susceptibility to interferences or impossibility of real time data acquisition. Using the neural networks can solve this problem. The computer simulations of various models of neural networks were done. The best result was obtained for network, which has as input signals: accelerating voltage, E...

  19. 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.

  20. 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.

  1. 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.

  2. Eliminating leakage current in voltage-controlled exchange-bias devices

    Science.gov (United States)

    Mahmood, Ather; Echtenkamp, Will; Street, Michael; Binek, Christian; Magnetic Heterostructures Team

    Manipulation of magnetism by electric field has drawn much attention due to the technological importance for low-power devices, and for understanding fundamental magnetoelectric phenomena. A manifestation of electrically controlled magnetism is voltage control of exchange bias (EB). Robust isothermal voltage control of EB was demonstrated near room temperature using a heterostructure of Co/Pd thin film and an exchange coupled single crystal of the antiferromagnetic Cr2O3 (Chromia). A major obstacle for EB in lithographically patterned Chromia based thin-film devices is to minimize the leakage currents at high electric fields (>10 kV/mm). By combining electrical measurements on patterned devices and conductive Atomic Force Microscopy of Chromia thin-films, we investigate the defects which form conducting paths impeding the application of sufficient voltage for demonstrating the isothermal EB switching in thin film heterostructures. Technological challenges in the device fabrication will be discussed. This project was supported by SRC through CNFD, an SRC-NRI Center, by C-SPIN, part of STARnet, and by the NSF through MRSEC Abstract DMR-0820521.

  3. 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.

  4. 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.

  5. 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.

  6. 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.)

  7. 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.

  8. 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.

  9. EB1 and EB3 promote cilia biogenesis by several centrosome-related mechanisms

    DEFF Research Database (Denmark)

    Schrøder, Jacob M; Larsen, Jesper; Komarova, Yulia

    2011-01-01

    surrounded by vesicles. Further, GST pull-down assays, mass spectrometry and immunoprecipitation indicated that EB1 and EB3 interact with proteins implicated in MT minus-end anchoring or vesicular trafficking to the cilia base, suggesting that EB1 and EB3 promote ciliogenesis by facilitating such trafficking...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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。

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. 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....

  6. 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...

  7. 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...

  8. Magnetoelectric switching of exchange bias.

    Science.gov (United States)

    Borisov, Pavel; Hochstrat, Andreas; Chen, Xi; Kleemann, Wolfgang; Binek, Christian

    2005-03-25

    The perpendicular exchange bias field, H(EB), of the magnetoelectric heterostructure Cr2O3(111)/(Co/Pt)(3) changes sign after field cooling to below the Néel temperature of Cr2O3 in either parallel or antiparallel axial magnetic and electric freezing fields. The switching of H(EB) is explained by magnetoelectrically induced antiferromagnetic single domains which extend to the interface, where the direction of their end spins controls the sign of H(EB). Novel applications in magnetoelectronic devices seem possible.

  9. 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.

  10. The Role of Microtubule End Binding (EB) Proteins in Ciliogenesis

    DEFF Research Database (Denmark)

    Schrøder, Jacob Morville

    in the biflagellate green alga Chlamydomonas (Pedersen et al., 2003), and is required for ciliogenesis in mouse fibroblasts (Schroder et al., 2007). However, the exact mechanism(s) involved and roles of the two additional mammalian members of the end binding (EB) protein family, EB2 and EB3, in ciliogenesis...... also form a heterodimeric complex that is likely to be functionally distinct from the homodimeric complexes (Komarova et al., 2009; De Groot et al., 2010). This thesis is based on experiments using small interfering (si) RNA and dominant-negative constructs to show that EB1 and EB3, but not EB2......, are required for assembly of primary cilia in cultured human cells. The EB3 - siRNA ciliary phenotype could be rescued by GFP-EB1 expression, and GFP-EB3 over expression resulted in elongated cilia. Transmission electron microscopy (TEM) revealed that EB3-depleted cells possess stumpy cilia, a disorganized...

  11. 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.

  12. Trapping of normal EB1 ligands in aggresomes formed by an EB1 deletion mutant

    Directory of Open Access Journals (Sweden)

    Askham Jon M

    2005-04-01

    Full Text Available Abstract Background EB1 is a microtubule tip-associated protein that interacts with the APC tumour suppressor protein and the p150glued subunit of dynactin. We previously reported that an EB1 deletion mutant that retains both of these interactions but does not directly associate with microtubules (EB1-ΔN2-GFP spontaneously formed perinuclear aggregates when expressed in COS-7 cells. Results In the present study live imaging indicated that EB1-ΔN2-GFP aggregates underwent dynamic microtubule-dependent changes in morphology and appeared to be internally cohesive. EB1-ΔN2-GFP aggregates were phase-dense structures that displayed microtubule-dependent accumulation around the centrosome, were immunoreactive for both the 20s subunit of the proteasome and ubiquitin, and induced the collapse of the vimentin cytoskeleton. Fractionation studies revealed that a proportion of EB1-ΔN2-GFP was detergent-insoluble and ubiquitylated, indicating that EB1-ΔN2-GFP aggregates are aggresomes. Immunostaining also revealed that APC and p150glued were present in EB1-ΔN2-GFP aggregates, whereas EB3 was not. Furthermore, evidence for p150glued degradation was found in the insoluble fraction of EB1-ΔN2-GFP transfected cultures. Conclusion Our data indicate that aggresomes can be internally cohesive and may not represent a simple "aggregate of aggregates" assembled around the centrosome. Our observations also indicate that a partially misfolded protein may retain the ability to interact with its normal physiological ligands, leading to their co-assembly into aggresomes. This supports the idea that the trapping and degradation of co-aggregated proteins might contribute to human pathologies characterised by aggresome formation.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. EB Frond wave energy converter - phase 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The EB Frond project is a wave energy programme developed by The Engineering Business (EB) from an original idea at Lancaster University. The EB Frond is a wave generator with a collector vane on top of an arm that pivots near the seabed. Phase 1 of the project demonstrated the technical feasibility of the project and provided proof of concept. Phase 2 involved further assesment of the technical and commercial viability of the concept through the development of mathematical and physical modelling methods. The work involved small-scale (1/25th) testing in wave tanks at Newcastle and Lancaster Universities and the development, verification and validation of a time domain mathematical model. The decision by EB to put on hold its renewable generation programme meant that plans to test at an intermediate scale (1/16th), assess different survival strategies in extreme wave conditions, carry out site characterisation for full-scale systems and to produce a robust economic model were not fulfilled. However, the mathematical and physical modelling work was used to develop an economic model for the Frond system. This produced a predicted unit cost of electricity by a pre-commercial 5 MW demonstration farm of about 17 pence/kWh. The report discusses the small-scale testing, test results, mathematical modelling, analysis and interpretation, survivability, the economic model and the development route to full-scale production.

  18. 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.

  19. 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.

  20. 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%.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.)

  6. 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...

  7. 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.

  8. EB1 is required for primary cilia assembly in fibroblasts

    DEFF Research Database (Denmark)

    Schrøder, Jacob M; Schneider, Linda; Christensen, Søren T

    2007-01-01

    EB1 is a small microtubule (MT)-binding protein that associates preferentially with MT plus ends and plays a role in regulating MT dynamics. EB1 also targets other MT-associated proteins to the plus end and thereby regulates interactions of MTs with the cell cortex, mitotic kinetochores, and diff......EB1 is a small microtubule (MT)-binding protein that associates preferentially with MT plus ends and plays a role in regulating MT dynamics. EB1 also targets other MT-associated proteins to the plus end and thereby regulates interactions of MTs with the cell cortex, mitotic kinetochores...... in the cilium/flagellum is unknown. We depleted EB1 from NIH3T3 fibroblasts by using siRNA and found that EB1 depletion causes a approximately 50% reduction in the efficiency of primary cilia assembly in serum-starved cells. Expression of dominant-negative EB1 also inhibited cilia formation, and expression...

  9. 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。

  10. 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.

  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. 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.

  13. 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

  14. 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

  15. Photospheric response to EB-like event

    CERN Document Server

    Danilovic, S; Barthol, P; Gandorfer, A; Gizon, L; Hirzberger, J; van Noort, T L Riethmüller M; Rodríguez, J Blanco; Iniesta, J C Del Toro; Suárez, D Orozco; Schmidt, W; Pillet, V Martínez; Knölker, M

    2016-01-01

    Ellerman Bombs are signatures of magnetic reconnection, which is an important physical process in the solar atmosphere. How and where they occur is a subject of debate. In this paper we analyse Sunrise/IMaX data together with 3D MHD simulations that aim to reproduce the exact scenario proposed for the formation of these features. Although the observed event seems to be more dynamic and violent than the simulated one, simulations clearly confirm the basic scenario for the production of EBs. The simulations also reveal the full complexity of the underlying process. The simulated observations show that the Fe I 525.02 nm line gives no information on the height where reconnection takes place. It can only give clues about the heating in the aftermath of the reconnection. The information on the magnetic field vector and velocity at this spatial resolution is, however, extremely valuable because it shows what numerical models miss and how they can be improved.

  16. Simulations for EBS Task Force BMT 1

    Energy Technology Data Exchange (ETDEWEB)

    Lempinen, A. [Marintel Ky, Turku (Finland)

    2006-12-15

    The Aespoe HRL International Joint Committee has set up a Task Force on Engineered Barrier Systems (EBS). Its long time objective is to develop effective tools for analysis of THM(C) behaviour of buffer and backfill. The idea of the Task Force is to offer a forum to develop the tools of the work groups. This BMT has two parts: BMT 1.1 and BMT 1.2 based on the performance of THM mock-up experiments on MX-80 bentonite by CEA and FEBEX bentonite by CIEMAT, respectively. Simulation results are presented here. These simulations are performed with Freefem++ software, which is a high-level programming language for solving partiel differential equations with finite element method. The mathematical model used is based on continuum thermodynamics. The simulations repeat the evolution of relevant THM variables of the experiments fairly well, but some modificatios of parameters is needed, especially in hydraulic behaviour. (orig.)

  17. 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...

  18. 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,...

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  3. 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.

  4. EB1 targets to kinetochores with attached, polymerizing microtubules.

    Science.gov (United States)

    Tirnauer, Jennifer S; Canman, Julie C; Salmon, E D; Mitchison, Timothy J

    2002-12-01

    Microtubule polymerization dynamics at kinetochores is coupled to chromosome movements, but its regulation there is poorly understood. The plus end tracking protein EB1 is required both for regulating microtubule dynamics and for maintaining a euploid genome. To address the role of EB1 in aneuploidy, we visualized its targeting in mitotic PtK1 cells. Fluorescent EB1, which localized to polymerizing ends of astral and spindle microtubules, was used to track their polymerization. EB1 also associated with a subset of attached kinetochores in late prometaphase and metaphase, and rarely in anaphase. Localization occurred in a narrow crescent, concave toward the centromere, consistent with targeting to the microtubule plus end-kinetochore interface. EB1 did not localize to kinetochores lacking attached kinetochore microtubules in prophase or early prometaphase, or upon nocodazole treatment. By time lapse, EB1 specifically targeted to kinetochores moving antipoleward, coupled to microtubule plus end polymerization, and not during plus end depolymerization. It localized independently of spindle bipolarity, the spindle checkpoint, and dynein/dynactin function. EB1 is the first protein whose targeting reflects kinetochore directionality, unlike other plus end tracking proteins that show enhanced kinetochore binding in the absence of microtubules. Our results suggest EB1 may modulate kinetochore microtubule polymerization and/or attachment.

  5. 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。

  6. 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).

  7. 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.

  8. 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.

  9. Antiviral activity of the EB peptide against zoonotic poxviruses

    Directory of Open Access Journals (Sweden)

    Altmann Sharon E

    2012-01-01

    Full Text Available Abstract Background The EB peptide is a 20-mer that was previously shown to have broad spectrum in vitro activity against several unrelated viruses, including highly pathogenic avian influenza, herpes simplex virus type I, and vaccinia, the prototypic orthopoxvirus. To expand on this work, we evaluated EB for in vitro activity against the zoonotic orthopoxviruses cowpox and monkeypox and for in vivo activity in mice against vaccinia and cowpox. Findings In yield reduction assays, EB had an EC50 of 26.7 μM against cowpox and 4.4 μM against monkeypox. The EC50 for plaque reduction was 26.3 μM against cowpox and 48.6 μM against monkeypox. A scrambled peptide had no inhibitory activity against either virus. EB inhibited cowpox in vitro by disrupting virus entry, as evidenced by a reduction of the release of virus cores into the cytoplasm. Monkeypox was also inhibited in vitro by EB, but at the attachment stage of infection. EB showed protective activity in mice infected intranasally with vaccinia when co-administered with the virus, but had no effect when administered prophylactically one day prior to infection or therapeutically one day post-infection. EB had no in vivo activity against cowpox in mice. Conclusions While EB did demonstrate some in vivo efficacy against vaccinia in mice, the limited conditions under which it was effective against vaccinia and lack of activity against cowpox suggest EB may be more useful for studying orthopoxvirus entry and attachment in vitro than as a therapeutic against orthopoxviruses in vivo.

  10. Studies on EB radiation effect on PA610

    Energy Technology Data Exchange (ETDEWEB)

    Yang Kebin; Zhang Huaming; Li Xiurong; Xiong Ruilin [Sichuan Forever Group Co. Ltd., China Academy of Engineering Physics, Miangany (China)

    2000-03-01

    Radiation effect of PA610 with polyfunctional monomer trially isocyanurate (TAIC) was studied, the results show that crosslinking effect of EB radiation on PA610 is obvious. After the PA610 samples were radiated by EB with dosage 75KGY, the physical characters of PA610 materials were greatly improved, especially their tensile strength being increased about 18% and their impact strength about 50%, but their water and oil absorption were decreased. So, EB radiation can enhance PA610 materials physical strength, resistance to solvents and water and increase their thermal-deformation temperature. (author)

  11. 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。

  12. 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.

  13. 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.

  14. THE CONCEPT OF INTEGRATED ENGINEERING AND BUSINESS (EB EDUCATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Michał Charlak

    2013-12-01

    Full Text Available In our approach to engineering and business education system an engineer is a man working as creator and user of technical products. We stress that the process of understanding and gaining knowledge of technical reality and creativity of engineers are the essential for EB concept . Next, we describe briefly three perspectives for building the system of innovative product origination as a basis for EB system: 1 designer’s perspective; 2 business perspective. 3 consumer perspective.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Recruitment of EB1, a master regulator of microtubule dynamics, to the surface of the Theileria annulata schizont.

    Directory of Open Access Journals (Sweden)

    Kerry L Woods

    2013-05-01

    Full Text Available The apicomplexan parasite Theileria annulata transforms infected host cells, inducing uncontrolled proliferation and clonal expansion of the parasitized cell population. Shortly after sporozoite entry into the target cell, the surrounding host cell membrane is dissolved and an array of host cell microtubules (MTs surrounds the parasite, which develops into the transforming schizont. The latter does not egress to invade and transform other cells. Instead, it remains tethered to host cell MTs and, during mitosis and cytokinesis, engages the cell's astral and central spindle MTs to secure its distribution between the two daughter cells. The molecular mechanism by which the schizont recruits and stabilizes host cell MTs is not known. MT minus ends are mostly anchored in the MT organizing center, while the plus ends explore the cellular space, switching constantly between phases of growth and shrinkage (called dynamic instability. Assuming the plus ends of growing MTs provide the first point of contact with the parasite, we focused on the complex protein machinery associated with these structures. We now report how the schizont recruits end-binding protein 1 (EB1, a central component of the MT plus end protein interaction network and key regulator of host cell MT dynamics. Using a range of in vitro experiments, we demonstrate that T. annulata p104, a polymorphic antigen expressed on the schizont surface, functions as a genuine EB1-binding protein and can recruit EB1 in the absence of any other parasite proteins. Binding strictly depends on a consensus SxIP motif located in a highly disordered C-terminal region of p104. We further show that parasite interaction with host cell EB1 is cell cycle regulated. This is the first description of a pathogen-encoded protein to interact with EB1 via a bona-fide SxIP motif. Our findings provide important new insight into the mode of interaction between Theileria and the host cell cytoskeleton.

  1. Recruitment of EB1, a Master Regulator of Microtubule Dynamics, to the Surface of the Theileria annulata Schizont

    KAUST Repository

    Woods, Kerry L.

    2013-05-09

    The apicomplexan parasite Theileria annulata transforms infected host cells, inducing uncontrolled proliferation and clonal expansion of the parasitized cell population. Shortly after sporozoite entry into the target cell, the surrounding host cell membrane is dissolved and an array of host cell microtubules (MTs) surrounds the parasite, which develops into the transforming schizont. The latter does not egress to invade and transform other cells. Instead, it remains tethered to host cell MTs and, during mitosis and cytokinesis, engages the cell\\'s astral and central spindle MTs to secure its distribution between the two daughter cells. The molecular mechanism by which the schizont recruits and stabilizes host cell MTs is not known. MT minus ends are mostly anchored in the MT organizing center, while the plus ends explore the cellular space, switching constantly between phases of growth and shrinkage (called dynamic instability). Assuming the plus ends of growing MTs provide the first point of contact with the parasite, we focused on the complex protein machinery associated with these structures. We now report how the schizont recruits end-binding protein 1 (EB1), a central component of the MT plus end protein interaction network and key regulator of host cell MT dynamics. Using a range of in vitro experiments, we demonstrate that T. annulata p104, a polymorphic antigen expressed on the schizont surface, functions as a genuine EB1-binding protein and can recruit EB1 in the absence of any other parasite proteins. Binding strictly depends on a consensus SxIP motif located in a highly disordered C-terminal region of p104. We further show that parasite interaction with host cell EB1 is cell cycle regulated. This is the first description of a pathogen-encoded protein to interact with EB1 via a bona-fide SxIP motif. Our findings provide important new insight into the mode of interaction between Theileria and the host cell cytoskeleton. 2013 Woods et al.

  2. 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.

  3. 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.

  4. 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。

  5. 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.

  6. 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

  7. 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。

  8. 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...

  9. 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.

  10. A single-photon sensitive ebCMOS camera: The LUSIPHER prototype

    Energy Technology Data Exchange (ETDEWEB)

    Barbier, R., E-mail: rbarbier@ipnl.in2p3.fr [Universite de Lyon, Universite Lyon 1, Lyon F-69003 (France); CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, Villeurbanne F-69622 (France); Cajgfinger, T.; Calabria, P.; Chabanat, E.; Chaize, D.; Depasse, P.; Doan, Q.T.; Dominjon, A.; Guerin, C.; Houles, J.; Vagneron, L. [Universite de Lyon, Universite Lyon 1, Lyon F-69003 (France); CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, Villeurbanne F-69622 (France); Baudot, J.; Dorokhov, A.; Dulinski, W.; Winter, M. [Universite Louis Pasteur Strasbourg, Strasbourg (France); CNRS/IN2P3, Institut Pluridisciplinaire Hubert Curien, Strasbourg F-67037 (France); Kaiser, C.T. [PHOTONIS Netherlands BV, Roden B.O. Box 60, 9300 AB Roden (Netherlands)

    2011-08-21

    Processing high-definition images with single-photon sensitivity acquired above 500 frames per second (fps) will certainly find ground-breaking applications in scientific and industrial domains such as nano-photonics. However, current technologies for low light imaging suffer limitations above the standard 30 fps to keep providing both excellent spatial resolution and signal-over-noise. This paper presents the state of the art on a promising way to answer this challenge, the electron bombarded CMOS (ebCMOS) detector. A large-scale ultra fast single-photon tracker camera prototype produced with an industrial partner is described. The full characterization of the back-thinned CMOS sensor is presented and a method for Point Spread Function measurements is elaborated. Then the study of the ebCMOS performance is presented for two different multi-alkali cathodes, S20 and S25. Point Spread Function measurements carried out on an optical test bench are analysed to extract the PSF of the tube by deconvolution. The resolution of the tube is studied as a function of temperature, high voltage and incident wavelength. Results are discussed for both multi-alkali cathodes as well as a Maxwellian modelization of the radial initial energy of the photo-electrons.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. Creep life simulations of EB welded copper overpack

    Energy Technology Data Exchange (ETDEWEB)

    Holmstroem, S.; Laukkanen, A.; Andersson, T. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2013-12-15

    The long term life predictions of copper overpack (sealed by EB welding in Finland) have previously been based on stress estimations that vary over a wide range, typically between 40-100 MPa. These values are usually not based on structural calculation including the EB-weld that increases the complexity of the stress state in the copper overpack. This report will attempt to pinpoint and simulate the stresses and strains developing in the copper overpack during its first decennia of repository service by advanced FEA simulations including the impact of the EB-weld. The main challenge of this work is the extrapolation of the creep strain response of OFP copper to the service relevant loads and temperatures. The uniaxial creep model is translated to a multiaxial constitutive equation form with adequate computational efficiency. The copper overpack strain and stress evolution has been simulated at up to 100 000 years at a conservative constant temperature of 80 deg C with 14 MPa of external pressure. The results indicate rapid creep relaxation in the initial stages after the load has been applied followed by limited creep strain accumulation thereafter. Local elastic-plastic and creep deformation is predicted at the EB weld root with a total strain of below 12 %. The predicted stresses after external loading and short term relaxation are moderate and the impact of weld residual stresses and the lower creep rupture properties of the EB seem not to be detrimental to the predicted long term creep response. The simulation results imply that the most crucial impact on the creep strain accumulation of the copper overpack is related to the OFP copper primary creep properties. The present study predicts sufficiently low creep strains for a 100 000 years canister life with the conservative assumption at a constant temperature of 80 deg C. However a sensitivity study on the impact of primary creep is strongly recommended due to contradicting analysis results from earlier FEA

  17. 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.

  18. 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.

  19. 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.

  20. 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。

  1. 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.

  2. 47 CFR 27.1214 - EBS spectrum leasing arrangements and grandfathered leases.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false EBS spectrum leasing arrangements and... Educational Broadband Service § 27.1214 EBS spectrum leasing arrangements and grandfathered leases. (a) A licensee in the EBS that is solely utilizing analog transmissions may enter into a spectrum...

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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.

  8. Cap-Gly proteins at microtubule plus ends: is EB1 detyrosination involved?

    Science.gov (United States)

    Bosson, Anouk; Soleilhac, Jean-Marc; Valiron, Odile; Job, Didier; Andrieux, Annie; Moutin, Marie-Jo

    2012-01-01

    Localization of CAP-Gly proteins such as CLIP170 at microtubule+ends results from their dual interaction with α-tubulin and EB1 through their C-terminal amino acids -EEY. Detyrosination (cleavage of the terminal tyrosine) of α-tubulin by tubulin-carboxypeptidase abolishes CLIP170 binding. Can detyrosination affect EB1 and thus regulate the presence of CLIP170 at microtubule+ends as well? We developed specific antibodies to discriminate tyrosinated vs detyrosinated forms of EB1 and detected only tyrosinated EB1 in fibroblasts, astrocytes, and total brain tissue. Over-expressed EB1 was not detyrosinated in cells and chimeric EB1 with the eight C-terminal amino acids of α-tubulin was only barely detyrosinated. Our results indicate that detyrosination regulates CLIPs interaction with α-tubulin, but not with EB1. They highlight the specificity of carboxypeptidase toward tubulin.

  9. Cap-Gly proteins at microtubule plus ends: is EB1 detyrosination involved?

    Directory of Open Access Journals (Sweden)

    Anouk Bosson

    Full Text Available Localization of CAP-Gly proteins such as CLIP170 at microtubule+ends results from their dual interaction with α-tubulin and EB1 through their C-terminal amino acids -EEY. Detyrosination (cleavage of the terminal tyrosine of α-tubulin by tubulin-carboxypeptidase abolishes CLIP170 binding. Can detyrosination affect EB1 and thus regulate the presence of CLIP170 at microtubule+ends as well? We developed specific antibodies to discriminate tyrosinated vs detyrosinated forms of EB1 and detected only tyrosinated EB1 in fibroblasts, astrocytes, and total brain tissue. Over-expressed EB1 was not detyrosinated in cells and chimeric EB1 with the eight C-terminal amino acids of α-tubulin was only barely detyrosinated. Our results indicate that detyrosination regulates CLIPs interaction with α-tubulin, but not with EB1. They highlight the specificity of carboxypeptidase toward tubulin.

  10. 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%.

  11. 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.

  12. 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。

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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。

  18. 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.

  19. EBS/C proton spectra from a virgin diamond crystal

    Energy Technology Data Exchange (ETDEWEB)

    Erich, M., E-mail: marko.erich@gmail.com [Laboratory of Physics, Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 552, Belgrade (Serbia); Kokkoris, M. [Department of Physics, National Technical University of Athens, Zografou Campus 157 80, Athens (Greece); Fazinić, S. [Laboratory for Ion Beam Interactions, Department of Experimental Physics, Institute Ruđer Bošković, Bijenička cesta 54, 10000 Zagreb (Croatia); Petrović, S. [Laboratory of Physics, Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 552, Belgrade (Serbia)

    2016-08-15

    In the present work, elastic backscattering channeling spectra, EBS/C, of protons in a 〈1 0 0〉 diamond crystal were experimentally and theoretically studied via a new computer simulation code. Proton incident energies for EBS/C spectra were in the energy range from 1.0 MeV to 1.9 MeV. The energy range was chosen in order to explore a distinct strong resonance of the {sup 12}C(p,p{sub 0}){sup 12}C elastic scattering at 1737 keV. The computer simulation code applied for the fitting of the experimental spectra in the random mode was compared with the corresponding SIMNRA results. In the channeling mode, it assumes a Gompertz type sigmoidal dechanneling function, which has two fitting parameters, x{sub c} and k, the dechanneling range and rate, respectively. It also uses α, ratio of the channeling to random energy losses, as a fitting parameter. It was observed that x{sub c} increases, k decreases and α stays relatively constant with the proton incident energy. These observations confirm the physical interpretation of the fitting parameters. Also, they constitute the basics for the further development of the code for the quantification of induced amorphization and depth profiling of implanted ions.

  20. Autoinhibition of TBCB regulates EB1-mediated microtubule dynamics.

    Science.gov (United States)

    Carranza, Gerardo; Castaño, Raquel; Fanarraga, Mónica L; Villegas, Juan Carlos; Gonçalves, João; Soares, Helena; Avila, Jesus; Marenchino, Marco; Campos-Olivas, Ramón; Montoya, Guillermo; Zabala, Juan Carlos

    2013-01-01

    Tubulin cofactors (TBCs) participate in the folding, dimerization, and dissociation pathways of the tubulin dimer. Among them, TBCB and TBCE are two CAP-Gly domain-containing proteins that together efficiently interact with and dissociate the tubulin dimer. In the study reported here we showed that TBCB localizes at spindle and midzone microtubules during mitosis. Furthermore, the motif DEI/M-COO(-) present in TBCB, which is similar to the EEY/F-COO(-) element characteristic of EB proteins, CLIP-170, and α-tubulin, is required for TBCE-TBCB heterodimer formation and thus for tubulin dimer dissociation. This motif is responsible for TBCB autoinhibition, and our analysis suggests that TBCB is a monomer in solution. Mutants of TBCB lacking this motif are derepressed and induce microtubule depolymerization through an interaction with EB1 associated with microtubule tips. TBCB is also able to bind to the chaperonin complex CCT containing α-tubulin, suggesting that it could escort tubulin to facilitate its folding and dimerization, recycling or degradation.

  1. The EB-ANUBAD translator: A hybrid scheme

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This article is aimed at describing a hybrid scheme for English to Bangla translation. The translated output in English scripts is useful for learning Bengali language. This is a significant contribution to Human Language Technology generation also.About two hundred million people in West Bengal and Tripura (two states in India) and in Bangladesh (a country whose people speak and write Bangla as their first language). This proposed translator would benefit Bengalee society because rural people are not usually very conversant with English. The English to Bangla Translator is being enhanced. This system (EnglishBangla-ANUBAD or EB-ANUBAD) takes a paragraph of English sentences as input sentences and produces equivalent Bangla sentences. EB-ANUBAD system is comprised of a preprocessor, morphological parser, semantic parser using English word ontology for context disambiguation, an electronic lexicon associated with grammatical information and a discourse processor,and also uses a lexical disambiguation analyzer. This system does not rely on a stochastic approach. Rather, it is based on a special kind of hybrid architecture of transformer and rule-based Natural Language Engineering (NLE) architectures along with various linguistic knowledge components of both English and Bangla.

  2. EBS/C proton spectra from a virgin diamond crystal

    Science.gov (United States)

    Erich, M.; Kokkoris, M.; Fazinić, S.; Petrović, S.

    2016-08-01

    In the present work, elastic backscattering channeling spectra, EBS/C, of protons in a diamond crystal were experimentally and theoretically studied via a new computer simulation code. Proton incident energies for EBS/C spectra were in the energy range from 1.0 MeV to 1.9 MeV. The energy range was chosen in order to explore a distinct strong resonance of the 12C(p,p0)12C elastic scattering at 1737 keV. The computer simulation code applied for the fitting of the experimental spectra in the random mode was compared with the corresponding SIMNRA results. In the channeling mode, it assumes a Gompertz type sigmoidal dechanneling function, which has two fitting parameters, xc and k, the dechanneling range and rate, respectively. It also uses α, ratio of the channeling to random energy losses, as a fitting parameter. It was observed that xc increases, k decreases and α stays relatively constant with the proton incident energy. These observations confirm the physical interpretation of the fitting parameters. Also, they constitute the basics for the further development of the code for the quantification of induced amorphization and depth profiling of implanted ions.

  3. 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.

  4. 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

  5. Identification and immunogenicity of microneme protein 2 (EbMIC2) of Eimeria brunetti.

    Science.gov (United States)

    Hoan, Tran Duc; Zhang, Zhenchao; Huang, Jingwei; Yan, Ruofeng; Song, Xiaokai; Xu, Lixin; Li, Xiangrui

    2016-03-01

    There have been only a few antigen genes of Eimeria brunetti reported up to now. In this study, the gene encoding the microneme protein 2 (EbMIC2) was isolated from oocysts of E. brunetti by RT-PCR and the immunogenicity of recombinant EbMIC2 was observed. The EbMIC2 was cloned into vector pMD19-T for sequencing. The sequence was compared with the published EbMIC2 gene from GenBank revealed homology of the nucleotide sequence and amino acids sequence were 99.43 and 98.63%, respectively. The correct recombinant pMD-EbMIC2 plasmid was inserted into the pET-28a (+) expressing vector and transformed into competent Escherichia coli BL21 cells for expression. The expressed product was analyzed using SDS-PAGE and Western-blot. The results indicated that the recombinant EbMIC2 protein was recognized strongly by serum from naturally infected chicken with E. brunetti. Rat rcEbMIC2 antisera bound to bands of about 36 kDa in the somatic extract of E. brunetti sporozoites. The recombinant plasmid pVAX1-EbMIC2 was constructed and then the efficacies of recombinant plasmid and recombinant protein were evaluated. The results of IgG antibody level and cytokines concentration suggested that recombinant EbMIC2 could increase the IgG antibody level and induce the expressions of cytokines. Animal challenge experiments demonstrated that the recombinant EbMIC2 protein and recombinant plasmid pVAX1-EbMIC2 could significantly increase the average body weight gains, decrease the mean lesion scores and the oocyst outputs of the immunized chickens and presented high anti-coccidial index. All results suggested that EbMIC2 could become an effective candidate for the development of new vaccine against E. brunetti infection.

  6. Selenium Distribution Pattern, Antineoplastic and Immunostimulatory Activities of a Novel Organoselenium Compound Eb

    Institute of Scientific and Technical Information of China (English)

    YANJun; DENGSheng-ju; KUANGBin; HEFei; LIUTao; ZENGHui-hui

    2004-01-01

    Aim To study the distribution pattern, antineoplastic activity and immtmocompetence of a novel organeselenium compotmd Eb and investigate its in vivo antineoplastic potential. Methods Eb was administered to Kunming mice (dosage, 0.1 g·kg-1·d-1) intragastrically for 7 successive days. The contents of selenium in heart, liver, spleen, kidneys, lungs, stomach, brain, muscle, and bone were determined by fluommetric method on the eighth day. MTT assay was used to study tumor growth inhibition of Eb in vitro, and lymphocyte transformation, hemolysin formation and phagocytosis assay were used to study its immunocompetence. Results After 7 days' administration of Eb, the tissue contents of selenium in liver, spleen, lungs, kidneys, and bone of mice increased, especially those in liver and spleen increased significantly, compared with controls; but no significant changes of such contents were fotmd in muscle, heart, brain, and stomach. Eb demonstrated inhibitory effects on human Bel-7402, BGC-823, and Calu-3 cancer cell lines in vitro. Eb also showed ability to enhance lymphocyte transformation and serum hemolysin formation in v/tro and increase the phagocytosis of macrophages. Conclusion The validated antitumor and immtmostimulatory activities of Eb suggest a hypothesis that Eb may behave as a biological response modifier when used as an antitumor agent. Eb is worthy of further study in developing a new antineoplastic and immunity enhancing agent in the light of its antitumor activity, immtmocompetenee and specific distribution in liver, lungs, kidneys, bone, and spleen.

  7. 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.

  8. 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.

  9. 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....

  10. 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.

  11. Simulations of EBS task force BMT 1.3

    Energy Technology Data Exchange (ETDEWEB)

    Lempinen, A. (Marintel Ky, Turku (Finland))

    2007-08-15

    The Aespoe HRL International Joint Committee has set up a Task Force on Engineered Barrier Systems (EBS). Its long time objective is to develop effective tools for analysis of THM(C) behaviour of buffer and backfill. The idea of the Task Force is to offer a forum to develop the tools of the work groups. Bench Mark Test (BMT) 1.3 was a small-scale heating test with no external water supply. The experiment was conducted by Technical University of Catalonia. It was a thermal-hydraulic-mechanical test, although only temperature was measured continuously. Simulation results are presented here. These simulations were performed with Freefem++ software, which is a high-level programming language for solving partial differential equations with finite element method. The mathematical model used is based on continuum thermodynamics. With the model improvements for BMT 1.3, also BMT 1.2 was recalculated. (orig.)

  12. 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.

  13. 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.

  14. 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.

  15. Madis Habakuk : aasta pärast alustab EBS Indias / Madis Habakuk ; interv. Taivo Paju

    Index Scriptorium Estoniae

    Habakuk, Madis, 1938-

    2003-01-01

    EBS Grupp tegutseb juba Hiinas ning kavatseb laieneda Indiasse. EBS Grupi president selgitab, kuidas toimub töötajate juhtimine ja kontroll suure vahemaa tagant, milline peaks olema usalduse ja kontrolli vahekord, ning mida mõista lojaalsuse all ettevõttes

  16. Synthesis and application of novel EB curable polyester urethane acrylate modified by linseed oil fatty acid

    Science.gov (United States)

    Jun, Li; Xuecheng, Ju; Min, Yi; Jinshan, Wei; Hongfei, Ha

    1999-06-01

    A novel polyester urethane acrylate resin modified by linseed oil fatty acid (LFA) was synthesized and EB curing coating was formulated in this work. When the coating cured by EB radiation on the timber, the cured coating was possessed of good performances.

  17. Madis Habakuk : aasta pärast alustab EBS Indias / Madis Habakuk ; interv. Taivo Paju

    Index Scriptorium Estoniae

    Habakuk, Madis, 1938-

    2003-01-01

    EBS Grupp tegutseb juba Hiinas ning kavatseb laieneda Indiasse. EBS Grupi president selgitab, kuidas toimub töötajate juhtimine ja kontroll suure vahemaa tagant, milline peaks olema usalduse ja kontrolli vahekord, ning mida mõista lojaalsuse all ettevõttes

  18. 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...

  19. Phosphorylation of EB2 by Aurora B and CDK1 ensures mitotic progression and genome stability.

    Science.gov (United States)

    Iimori, Makoto; Watanabe, Sugiko; Kiyonari, Shinichi; Matsuoka, Kazuaki; Sakasai, Ryo; Saeki, Hiroshi; Oki, Eiji; Kitao, Hiroyuki; Maehara, Yoshihiko

    2016-03-31

    Temporal regulation of microtubule dynamics is essential for proper progression of mitosis and control of microtubule plus-end tracking proteins by phosphorylation is an essential component of this regulation. Here we show that Aurora B and CDK1 phosphorylate microtubule end-binding protein 2 (EB2) at multiple sites within the amino terminus and a cluster of serine/threonine residues in the linker connecting the calponin homology and end-binding homology domains. EB2 phosphorylation, which is strictly associated with mitotic entry and progression, reduces the binding affinity of EB2 for microtubules. Expression of non-phosphorylatable EB2 induces stable kinetochore microtubule dynamics and delays formation of bipolar metaphase plates in a microtubule binding-dependent manner, and leads to aneuploidy even in unperturbed mitosis. We propose that Aurora B and CDK1 temporally regulate the binding affinity of EB2 for microtubules, thereby ensuring kinetochore microtubule dynamics, proper mitotic progression and genome stability.

  20. Character-Size Optimization for Reducing the Number of EB Shots of MCC Lithographic Systems

    Science.gov (United States)

    Sugihara, Makoto

    We propose a character size optimization technique to reduce the number of EB shots of multi-column-cell (MCC) lithographic systems in which transistor patterns are projected with multiple column cells in parallel. Each and every column cell is capable of projecting patterns with character projection (CP) and variable shaped beam (VSB) methods. Seeking the optimal character size of characters contributes to minimizing the number of EB shots and reducing the fabrication cost for ICs. Experimental results show that the character size optimization achieved 70.6% less EB shots in the best case with an available electron beam (EB) size. Our technique also achieved 40.6% less EB shots in the best case than a conventional character sizing technique.

  1. 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....

  2. 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...

  3. 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.

  4. 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.

  5. Reactive Transport and Coupled THM Processes in Engineering Barrier Systems (EBS)

    Energy Technology Data Exchange (ETDEWEB)

    Steefel, Carl; Rutqvist, Jonny; Tsang, Chin-Fu; Liu, Hui-Hai; Sonnenthal, Eric; Houseworth, Jim; Birkholzer, Jens

    2010-08-31

    Geological repositories for disposal of high-level nuclear wastes generally rely on a multi-barrier system to isolate radioactive wastes from the biosphere. The multi-barrier system typically consists of a natural barrier system, including repository host rock and its surrounding subsurface environment, and an engineering barrier system (EBS). EBS represents the man-made, engineered materials placed within a repository, including the waste form, waste canisters, buffer materials, backfill and seals (OECD, 2003). EBS plays a significant role in the containment and long-term retardation of radionuclide release. EBS is involved in complex thermal, hydrogeological, mechanical, chemical and biological processes, such as heat release due to radionuclide decay, multiphase flow (including gas release due to canister corrosion), swelling of buffer materials, radionuclide diffusive transport, waste dissolution and chemical reactions. All these processes are related to each other. An in-depth understanding of these coupled processes is critical for the performance assessment (PA) for EBS and the entire repository. Within the EBS group of Used Fuel Disposition (UFD) Campaign, LBNL is currently focused on (1) thermal-hydraulic-mechanical-chemical (THMC) processes in buffer materials (bentonite) and (2) diffusive transport in EBS associated with clay host rock, with a long-term goal to develop a full understanding of (and needed modeling capabilities to simulate) impacts of coupled processes on radionuclide transport in different components of EBS, as well as the interaction between near-field host rock (e.g., clay) and EBS and how they effect radionuclide release. This final report documents the progress that LBNL has made in its focus areas. Specifically, Section 2 summarizes progress on literature review for THMC processes and reactive-diffusive radionuclide transport in bentonite. The literature review provides a picture of the state-of-the-art of the relevant research areas

  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. 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.

  8. The TT, TB, EB and BB correlations in anisotropic inflation

    CERN Document Server

    Chen, Xingang; Firouzjahi, Hassan; Wang, Yi

    2014-01-01

    Recently the BICEP2 experiment has detected the B-mode in the CMB polarization map. The ongoing and future experiments will measure the B-mode from different sky coverage and frequency bands, with the potential to reveal non-trivial features in polarization map. In this work we study the TT, TB, EB and BB correlations associated with the B-mode polarization of CMB map in models of charged anisotropic inflation. The model contains a complex inflaton field which is charged under the $U(1)$ gauge. We calculate the statistical anisotropies generated in the power spectra of the curvature perturbation, the tensor perturbation and their cross-correlation. It is shown that the asymmetry in tensor power spectrum is a very sensitive probe of the gauge coupling. While the level of statistical anisotropy in temperature power spectrum can be small and satisfy the observational bounds, the interactions from the gauge coupling can induce large directional dependence in tensor modes. This will leave interesting anisotropic f...

  9. 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...

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. Near field and altered zone environmental report Volume I: technical bases for EBS design

    Energy Technology Data Exchange (ETDEWEB)

    Wilder, D. G., LLNL

    1997-08-01

    This report presents an updated summary of results for the waste package (WP) and engineered barrier system (EBS) evaluations, including materials testing, waste-form characterization, EBS performance assessments, and near-field environment (NFE) characterization. Materials testing, design criteria and concept development, and waste-form characterization all require an understanding of the environmental conditions that will interact with the WP and EBS. The Near-Field Environment Report (NFER) was identified in the Waste Package Plan (WPP) (Harrison- Giesler, 1991) as the formal means for transmitting and documenting this information.

  17. Gas and RRR Distribution in High Purity Niobium EB Welded in Ultra-High Vacuum.

    OpenAIRE

    Anakhov, S.; Singer, X.; W. Singer; Wen, H.

    2006-01-01

    Electron beam (EB) welding in UHV (ultra-high vacuum, 10(-5) divided by 10(-8) mbar) is applied in the standard fabrication of high gradient niobium superconducting radio frequency (SRF) cavities of TESLA design. The quality of EB welding is critical for cavity performance. Experimental data of gas content (H-2, O-2, N-2) and RRR (residual resistivity ratio) measurements in niobium (Nb) welding seams are presented. EB welding in UHV conditions allow to preserve low gas content (1 divided by 3...

  18. 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

  19. Closing photoconductive semiconductor switches

    Energy Technology Data Exchange (ETDEWEB)

    Loubriel, G.M.; Zutavern, F.J.; Hjalmarson, H.P.; O' Malley, M.W.

    1989-01-01

    One of the most important limitations of Photoconductive Semiconductor Switches (PCSS) for pulsed power applications is the high laser powers required to activate the switches. In this paper, we discuss recent developments on two different aspects of GaAs PCSS that result in reductions in laser power by a factor of nearly 1000. The advantages of using GaAs over Si are many. First of all, the resistivity of GaAs can be orders of magnitude higher than that of the highest resistivity Si material, thus allowing GaAs switches to withstand dc voltages without thermal runaway. Secondly, GaAs has a higher carrier mobility than Si and, thus, is more efficient (per carrier). Finally, GaAs switches can have naturally fast (ns) opening times at room temperature and low fields, microsecond opening times at liquid nitrogen temperature of 77 K, or, on demand, closing and opening at high fields and room temperature by a mechanism called lock-on (see Ref. 1). By contrast, Si switches typically opening times of milliseconds. The amount of laser light required to trigger GaAs for lock-on, or at 77 K, is about three orders of magnitude lower than at room temperature. In this paper we describe the study of lock-on in GaAs and InP, as well as switching of GaAs at 77 K. We shall show that when GaAs is switched at 77 K, the carrier lifetime is about three orders of magnitude longer than it is at room temperature. We shall explain the change in lifetime in terms of the change in electron capture cross section of the deep levels in GaAs (these are defect or impurity levels in the band gap). In the second section, we describe the lock-on effect, now seen in GaAs and InP, and at fields as high as 70 kV/cm. We show how lock-on can be tailored by changing the GaAs temperature or by neutron bombardment. In the third section, we discuss possible lock-on mechanisms. 5 refs., 5 figs.

  20. Simulation on Soft-Switching PWM Converter with High Power Factor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new PWM converter based on soft-switching is introduced. The converter uses a minimum number of devices, and requires less switching operations than conventional techniques. Switching is realized solely in a ZVS (zero voltage switching) mode,therefore the loss is reduced and EMI (electromagnetic interference) is suppressed. The paper analyzes the operation of ZVS, and discusses the methods for maintaining a unit power factor and constant DC voltage. Changing the modulation index M and the phase angle θ keeps the input current in phase with the voltage. It also keeps the current sinusoidal, and ensures a constant output voltage.

  1. Simulation Research of Transient Over-voltage on High-voltage Shunt Capacitor Banks

    Institute of Scientific and Technical Information of China (English)

    HU Quan-wei; ZHOU Xing-xing; SI Wen-rong; ZHANG Yang; LI Jur-hao; LI Yan-ming

    2011-01-01

    With the development of power systems,a large number of shunt capacitors are used to improve power quality in the distribution network.The shunt capacitor banks are operated much frequently,as a result,the capacitor banks will bear large numbers of over-voltage inevitably.If the over-voltage exceeds certain amplitude,the capacitor will be damaged.This paper aims at the capacitor banks in the 35 kV side of Shanghai Xu-xing 500 kV substation,and applies ATP-EMTP to simulate the over-voltages generated by operating the switches under different angles of the source.Finally,according to the results of simulation and theoretical analysis,a best choice (i.e.angles of the source) to switch on capacitor banks is proposed.In this case the over-voltage on the capacitor will be limited to lowest.

  2. Gate-controlled conductance switching in DNA

    Science.gov (United States)

    Xiang, Limin; Palma, Julio L.; Li, Yueqi; Mujica, Vladimiro; Ratner, Mark A.; Tao, Nongjian

    2017-02-01

    Extensive evidence has shown that long-range charge transport can occur along double helical DNA, but active control (switching) of single-DNA conductance with an external field has not yet been demonstrated. Here we demonstrate conductance switching in DNA by replacing a DNA base with a redox group. By applying an electrochemical (EC) gate voltage to the molecule, we switch the redox group between the oxidized and reduced states, leading to reversible switching of the DNA conductance between two discrete levels. We further show that monitoring the individual conductance switching allows the study of redox reaction kinetics and thermodynamics at single molecular level using DNA as a probe. Our theoretical calculations suggest that the switch is due to the change in the energy level alignment of the redox states relative to the Fermi level of the electrodes.

  3. Altitude Correction of Switching Impulse Flashover Voltage of Tower Gaps With V-shaped Insulator Strings for HVDC Power Transmission Lines%高压直流输电线路V型串塔头间隙操作冲击放电电压的海拔校正

    Institute of Scientific and Technical Information of China (English)

    廖蔚明; 丁玉剑; 孙昭英; 宿志一

    2012-01-01

    介绍了采用相同结构的真型尺寸v型绝缘子串模拟塔头间隙存小同海拔地区开展操作冲击放电特性对比试验取得的成果。根据在北京和西藏(海拔4300m)试验基地获得的塔头『日J隙操作冲击放电特性曲线,采用插值法计算了海拔4000m及以下地区的塔头间隙操作冲击放电曲线。经分析计算,得出了适合海拔4000m及以下地区高压直流线路塔头间隙海拔校正的计算公式。还将通过试验得出的海拔校正计算公式与目前常用标准IEC60071—2—1996推荐的海拔校正计算公式进行了对比,分析了两者的修正因子m值的差别及对修正电压的影响。%The results obtained from contrast tests on switching impulse flashover characteristics of tower gaps under different altitudes by two simulation models with true sizes and actual layouts for V-shaped insulator strings are presented. Based on the curves of switching impulse flashover characteristics of tower gaps obtained respectively from test bases located at Beijing and Tibet individually and the latter is at the region with altitude of 4 300 m, the curves of switching impulse flashover characteristics for tower gaps located at the regions with altitudes of 4 000 m and below are calculated by interpolation method. After analysis and calculation, the altitude-corrected calculation formula of switching impulse flashover characteristics curves for tower gaps, which is suitable to the regions with altitudes of 4 000 m and below, is obtained. The comparison of altitude correction computing formula obtained from tests with the formula recommended by IEC 60071-2: 1996, which is common used currently, is performed, and the difference between the values of correction factors m in the two formulae as well as the impact of the two correction factors on switching impulse flashover voltage are analyzed.

  4. Evaluation of the PetrifilmTM EB and TEMPO® EB systems with ISO 21528-2:2004 method for the count of Enterobacteriaceae in milk

    Directory of Open Access Journals (Sweden)

    Andréia Cirolini

    2013-09-01

    Full Text Available The development of alternative microbiological techniques is driven by the necessity to meet the current needs to deliver rapid results in the manufacturing process of foods, but it is important that these methods be evaluated for each application. The objective of the present study was to assess the PetrifilmTM EB and the TEMPO® EB systems with ISO 21528-2:2004 for the count of Enterobacteriaceae in pasteurized and UHT milk samples. We analyzed the microflora of 141 pasteurized milk samples, 15 samples of artificially contaminated pasteurized milk and 15 samples of artificially contaminated UHT milk. Investigation of the method PetrifilmTM EB and ISO 21528:2 regression analysis showed a high correlation in the samples, r = 0.90 for the microflora of pasteurized milk, r = 0.98 for artificially contaminated pasteurized milk and r = 0.99 for the artificially contaminated UHT milk. In evaluating the system TEMPO EB ® method and ISO 21528:2 correlation was also significant in the analyzed samples, with r = 0.86 for the microflora of pasteurized milk, r = 0.96 for artificially contaminated pasteurized milk and r = 0.99 for artificially contaminated UHT milk. No statistically significant differences were observed between the three methods conducted to analyze artificially contaminated pasteurized and UHT milk at three inoculum levels. In conclusion, the PetrifilmTM EB system and the TEMPO® EB system may be an alternative to the ISO 21528-2:2004 for the Enterobacteriaceae assay for milk as because of the ease-of-operation and the time reduction achieved for conducting the microbiological assay using these systems.

  5. Towards energy efficient climate control in storage of tulip bulbs. Pilot EB-01; Naar een energiezuiniger klimaatbeheersing bij de bewaring van tulpenbollen. Praktijkproef EB-01

    Energy Technology Data Exchange (ETDEWEB)

    Gude, H.; Dijkema, M.

    2005-09-15

    The aim of this project is to enable energy conservation in the storage of tulip bulbs. To this end, it should be examined if the agent EB-01 (1-methylcycloprene, a protection agent for plants) can be used in practical cells that are not entirely leak proof and if it offers sufficient protection against ethylene damage [Dutch] Doel van dit project is om energiebesparing bij de bewaring van tulpenbollen mogelijk te maken. Om dat te realiseren wordt onderzocht of het middel EB-01 (1- methylcyclopropeen, een beschermingsmiddel voor planten) toepasbaar is in niet volledig lekdichte praktijkcellen en voldoende bescherming tegen ethyleenschade biedt.

  6. Nord ja EBS tahavad liituda Tallinna Ülikooliga / Igor Taro, Anu Mõistlik

    Index Scriptorium Estoniae

    Taro, Igor

    2001-01-01

    Erakõrgkoolid Akadeemia Nord ja EBS loodavad järgmisel õppeaastal saada allasutusteks Tallinna Ülikoolis, mida on asunud looma Tallinna Pedagoogikaülikool, Eesti Kunstiakadeemia ja Eesti Humanitaarinstituut

  7. E.B. Forsythe National Wildlife Refuge : Annual narrative report : Calendar year 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for E.B. Forsythe National Wildlife Refuge outlines Refuge accomplishments during the 1989 calendar year. The report begins with a...

  8. E.B. Forsythe National Wildlife Refuge : Annual narrative report : Calendar year 1991

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for E.B. Forsythe National Wildlife Refuge outlines Refuge accomplishments during the 1991 calendar year. The report begins with a...

  9. E.B. Forsythe National Wildlife Refuge : Annual narrative report : Calendar year 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for E.B. Forsythe National Wildlife Refuge outlines Refuge accomplishments during the 1992 calendar year. The report begins with a...

  10. Gas and RRR distribution in high purity Niobium EB welded in Ultra-High Vacuum

    Science.gov (United States)

    Anakhov, S.; Singer, X.; Singer, W.; Wen, H.

    2006-05-01

    Electron beam (EB) welding in UHV (ultra-high vacuum, 10-5÷10-8 mbar) is applied in the standard fabrication of high gradient niobium superconducting radio frequency (SRF) cavities of TESLA design. The quality of EB welding is critical for cavity performance. Experimental data of gas content (H2, O2, N2) and RRR (residual resistivity ratio) measurements in niobium (Nb) welding seams are presented. EB welding in UHV conditions allow to preserve low gas content (1÷3 wt. ppm hydrogen and 5÷7 ppm oxygen and nitrogen), essential for high values of RRR — 350÷400 units. Gas content redistribution in the electron beam welded and heat affected region take place in the welding process. Correlation between gas solubility parameters, RRR and thermal conductivity are presented. Mechanisms of gas solubility in EB welding process are discussed.

  11. E.B. Forsythe National Wildlife Refuge : Annual narrative report : Calendar year 1990

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for E.B. Forsythe National Wildlife Refuge outlines Refuge accomplishments during the 1990 calendar year. The report begins with a...

  12. Nord ja EBS tahavad liituda Tallinna Ülikooliga / Igor Taro, Anu Mõistlik

    Index Scriptorium Estoniae

    Taro, Igor

    2001-01-01

    Erakõrgkoolid Akadeemia Nord ja EBS loodavad järgmisel õppeaastal saada allasutusteks Tallinna Ülikoolis, mida on asunud looma Tallinna Pedagoogikaülikool, Eesti Kunstiakadeemia ja Eesti Humanitaarinstituut

  13. Disposal systems evaluations and tool development : Engineered Barrier System (EBS) evaluation.

    Energy Technology Data Exchange (ETDEWEB)

    Rutqvist, Jonny (LBNL); Liu, Hui-Hai (LBNL); Steefel, Carl I. (LBNL); Serrano de Caro, M. A. (LLNL); Caporuscio, Florie Andre (LANL); Birkholzer, Jens T. (LBNL); Blink, James A. (LLNL); Sutton, Mark A. (LLNL); Xu, Hongwu (LANL); Buscheck, Thomas A. (LLNL); Levy, Schon S. (LANL); Tsang, Chin-Fu (LBNL); Sonnenthal, Eric (LBNL); Halsey, William G. (LLNL); Jove-Colon, Carlos F.; Wolery, Thomas J. (LLNL)

    2011-01-01

    Key components of the nuclear fuel cycle are short-term storage and long-term disposal of nuclear waste. The latter encompasses the immobilization of used nuclear fuel (UNF) and radioactive waste streams generated by various phases of the nuclear fuel cycle, and the safe and permanent disposition of these waste forms in geological repository environments. The engineered barrier system (EBS) plays a very important role in the long-term isolation of nuclear waste in geological repository environments. EBS concepts and their interactions with the natural barrier are inherently important to the long-term performance assessment of the safety case where nuclear waste disposition needs to be evaluated for time periods of up to one million years. Making the safety case needed in the decision-making process for the recommendation and the eventual embracement of a disposal system concept requires a multi-faceted integration of knowledge and evidence-gathering to demonstrate the required confidence level in a deep geological disposal site and to evaluate long-term repository performance. The focus of this report is the following: (1) Evaluation of EBS in long-term disposal systems in deep geologic environments with emphasis on the multi-barrier concept; (2) Evaluation of key parameters in the characterization of EBS performance; (3) Identification of key knowledge gaps and uncertainties; and (4) Evaluation of tools and modeling approaches for EBS processes and performance. The above topics will be evaluated through the analysis of the following: (1) Overview of EBS concepts for various NW disposal systems; (2) Natural and man-made analogs, room chemistry, hydrochemistry of deep subsurface environments, and EBS material stability in near-field environments; (3) Reactive Transport and Coupled Thermal-Hydrological-Mechanical-Chemical (THMC) processes in EBS; and (4) Thermal analysis toolkit, metallic barrier degradation mode survey, and development of a Disposal Systems

  14. Complete genome sequence of "Thioalkalivibrio sulfidophilus" HL-EbGr7.

    Science.gov (United States)

    Muyzer, Gerard; Sorokin, Dimitry Yu; Mavromatis, Konstantinos; Lapidus, Alla; Clum, Alicia; Ivanova, Natalia; Pati, Amrita; d'Haeseleer, Patrick; Woyke, Tanja; Kyrpides, Nikos C

    2011-02-14

    "Thioalkalivibrio sulfidophilus" HL-EbGr7 is an obligately chemolithoautotrophic, haloalkaliphilic sulfur-oxidizing bacterium (SOB) belonging to the Gammaproteobacteria. The strain was found to predominate a full-scale bioreactor, removing sulfide from biogas. Here we report the complete genome sequence of strain HL-EbGr7 and its annotation. The genome was sequenced within the Joint Genome Institute Community Sequencing Program, because of its relevance to the sustainable removal of sulfide from bio- and industrial waste gases.

  15. Switching antidepressants

    African Journals Online (AJOL)

    by this time.4. Next-step ... and the side-effects are minimal), switching to an alternative antidepressant (if .... the new SSRI initiated immediately at the former therapeutic equivalent dose ... weeks because of the long half-life of its active metabolite, .... interactions with second-generation antidepressants: an update. Clin Ther.

  16. Diode-assisted buck-boost voltage source inverters

    DEFF Research Database (Denmark)

    Gao, F.; Loh, P.C.; Teodorescu, Remus

    2007-01-01

    charging and discharging processes of passive components reveals that the dc-link voltage can alternate between two levels, which therefore demonstrate the phenomena that the specified modulation schemes should note. A modulation scheme that can achieve optimized harmonic switching is first designed...... with symmetrical state placement in each switching sequence to avoid unnecessary voltage stress across both passive and active components. To reduce the total commutation count, the designed modulation scheme is then modified without increasing voltage stress. All theoretical findings were verified experimentally...... using a number of scale-down laboratory prototypes....

  17. 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.

  18. The Leber congenital amaurosis protein AIPL1 and EB proteins co-localize at the photoreceptor cilium.

    Directory of Open Access Journals (Sweden)

    Juan Hidalgo-de-Quintana

    Full Text Available The aim of this study was to investigate the interaction and co-localization of novel interacting proteins with the Leber congenital amaurosis (LCA associated protein aryl hydrocarbon receptor interacting protein-like 1 (AIPL1.The CytoTrapXR yeast two-hybrid system was used to screen a bovine retinal cDNA library. A novel interaction between AIPL1 and members of the family of EB proteins was confirmed by directed yeast two-hybrid analysis and co-immunoprecipitation assays. The localization of AIPL1 and the EB proteins in cultured cells and in retinal cryosections was examined by immunofluorescence microscopy and cryo-immunogold electron microscopy.Yeast two-hybrid (Y2H analysis identified the interaction between AIPL1 and the EB proteins, EB1 and EB3. EB1 and EB3 were specifically co-immunoprecipitated with AIPL1 from SK-N-SH neuroblastoma cells. In directed 1:1 Y2H analysis, the interaction of EB1 with AIPL1 harbouring the LCA-causing mutations A197P, C239R and W278X was severely compromised. Immunofluorescent confocal microscopy revealed that AIPL1 did not co-localize with endogenous EB1 at the tips of microtubules, endogenous EB1 at the microtubule organising centre following disruption of the microtubule network, or with endogenous β-tubulin. Moreover, AIPL1 did not localize to primary cilia in ARPE-19 cells, whereas EB1 co-localized with the centrosomal marker pericentrin at the base of primary cilia. However, both AIPL1 and the EB proteins, EB1 and EB3, co-localized with centrin-3 in the connecting cilium of photoreceptor cells. Cryo-immunogold electron microscopy confirmed the co-localization of AIPL1 and EB1 in the connecting cilia in human retinal photoreceptors.AIPL1 and the EB proteins, EB1 and EB3, localize at the connecting cilia of retinal photoreceptor cells, but do not co-localize in the cellular microtubule network or in primary cilia in non-retinal cells. These findings suggest that AIPL1 function in these cells is not related

  19. 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

  20. Analysis and Research of E-commerce Platform Based on ebXML%基于ebXML的电子商务平台分析与研究

    Institute of Scientific and Technical Information of China (English)

    阮梦黎

    2009-01-01

    ebXML是由UN/CEFACT和OASIS共同倡导、全球参与开发和使用的一组支持模块化电子商务框架的规范,是基于XML的,它的目标是提供一种全球化的、开放的、基于XML的架构,使不同企业规模的用户之间的电子商务交换能够成功、安全和可靠地进行.本文以ebXML的体系结构及其在电子商务中的应用为主题进行分析和研究.%ebXML,based on XML, is a group of rules which is advocated coordinately by UN/CEFACT and OASIS and explored and used globally. Its taget is to provide a global and open framework based on XML which can enable different users of different enterprise scale to exchange e-commerce successfully, safely and reliably. This thesis mainly analyse and study the framework of ebXML and its application in e-commerce.

  1. EB1089抑制肝癌细胞增殖的研究%Regulatory mechanism of EB1089 for hepatocarcinoma cell proliferation

    Institute of Scientific and Technical Information of China (English)

    骆文静; 陈景元; 张雪萍; 王文亮; 陈耀明; 赵芳

    2004-01-01

    目的探讨维生素D类似物EB1089对肝癌细胞增殖的可能机制.方法体外培养了肝癌细胞株HHCC细胞,培养时添加10、10和1nmol/LEB1089分别作用2d、4d、6d后,用四唑蓝比色实验(MTT)、平板克隆形成实验检测细胞的存活和生长;用电子显微镜和流式细胞仪方法检测细胞凋亡;用Wester blot方法检测蛋白的表达.结果EB1089可以抑制肝癌细胞增殖(抑制率为17.50%~72.14%),诱导肝癌细胞发生凋亡.10nmol/L EB1089作用肝癌细胞4d可使p27kipl和PTEN蛋白表达增加.结论EB1089对于人肝癌细胞的增殖具有抑制作用,能机诱导肝癌细胞凋亡,增加肝癌细胞中p27kipl和PTEN蛋白的表达.

  2. A technique to reduce plasma armature formation voltage

    Energy Technology Data Exchange (ETDEWEB)

    Jamison, K.A. (Science Applications International Corp., Shalimar, FL (US)); Littrell, D.M. (Air Force Armament Lab., Eglin AFB, FL (United States))

    1991-01-01

    The initiation of a plasma armature by foil vaporization in a railgun is often accompanied by a large, fast, voltage transient appearing on both the breech and muzzle of the gun. For a railgun driven by an inductor/opening switch power supply, this voltage transient becomes a concern during current commutation from the switch to the railgun. To lessen the requirements on the opening switch, techniques must be found to reduce the armature formation voltage. This paper presents the experimental results from railgun firings at AFATL's Electromagnetic Launcher Basic Research Facility (Site A-15, Eglin Air Force Base, Florida) using different shapes of initiation foils. These foils have been designed to vaporize into a plasma armature with reduced transient voltages. A design criteria was developed to ensure that all portions of the foil vaporize at slightly different times.

  3. New Control Technique Applied in Dynamic Voltage Restorer for Voltage Sag Mitigation

    Directory of Open Access Journals (Sweden)

    Rosli Omar

    2010-01-01

    Full Text Available The Dynamic Voltage Restorer (DVR was a power electronics device that was able to compensate voltage sags on critical loads dynamically. The DVR consists of VSC, injection transformers, passive filters and energy storage (lead acid battery. By injecting an appropriate voltage, the DVR restores a voltage waveform and ensures constant load voltage. There were so many types of the control techniques being used in DVR for mitigating voltage sags. The efficiency of the DVR depends on the efficiency of the control technique involved in switching the inverter. Problem statement: Simulation and experimental investigation toward new algorithms development based on SVPWM. Understanding the nature of DVR and performance comparisons between the various controller technologies available. The proposed controller using space vector modulation techniques obtain higher amplitude modulation indexes if compared with conventional SPWM techniques. Moreover, space vector modulation techniques can be easily implemented using digital processors. Space vector PWM can produce about 15% higher output voltage than standard Sinusoidal PWM. Approach: The purpose of this research was to study the implementation of SVPWM in DVR. The proposed control algorithm was investigated through computer simulation by using PSCAD/EMTDC software. Results: From simulation and experimental results showed the effectiveness and efficiency of the proposed controller based on SVPWM in mitigating voltage sags in low voltage distribution systems. It was concluded that its controller also works well both in balance and unbalance conditions of voltages. Conclusion/Recommendations: The simulation and experimental results of a DVR using PSCAD/EMTDC software based on SVPWM technique showed clearly the performance of the DVR in mitigating voltage sags. The DVR operates without any difficulties to inject the appropriate voltage component to correct rapidly any anomaly in the supply voltage to keep the

  4. Composite Dielectric Materials for Electrical Switching

    Energy Technology Data Exchange (ETDEWEB)

    Modine, F.A.

    1999-04-25

    Composites that consist of a dielectric host containing a particulate conductor as a second phase are of interest for electrical switching applications. Such composites are "smart" materials that can function as either voltage or current limiters, and the difference in fimction depends largely upon whether the dielectric is filled to below or above the percolation threshold. It also is possible to combine current and voltage limiting in a single composite to make a "super-smart" material.

  5. Analysis of a novel phase-shifted soft switch converter

    Institute of Scientific and Technical Information of China (English)

    蒋志宏; 黄立培; 张义

    2002-01-01

    In this paper, on the basis of the phase-shifted controlled zero-voltage-switch (ZVS) full-bridge converter with pulse width modulation (PWM), a novel zero-voltage and zero-current switch (ZVZCS) PWM converter using a simple auxiliary circuit was designed. The ZVZCS soft switch is achieved by the resonance among the resisting electromagnetic deflection capacitor, the capacitor of the simple auxiliary network and the leakage inductor of transformer. There are no dissipation devices of the saturation inductor and the auxiliary switch in the converter, meantime the capacitor of the auxiliary circuit is also used to clamp the voltage of the rectifier, and there is no additional clamped circuit. There is no big circulating current in the converter, all the active and passive devices work on the condition of the low current and voltage stress, and the proposed converter has wide load range and small duty loss.

  6. EDITORIAL: Molecular switches at surfaces Molecular switches at surfaces

    Science.gov (United States)

    Weinelt, Martin; von Oppen, Felix

    2012-10-01

    electron-vibration coupling in transport through single moleculesKatharina J Franke and Jose Ignacio Pascual Vibrational heating in single-molecule switches: an energy-dependent density-of-states approachT Brumme, R Gutierrez and G Cuniberti Reversible switching of single tin phthalocyanine molecules on the InAs(111)A surfaceC Nacci, K Kanisawa and S Fölsch Tuning the interaction between carbon nanotubes and dipole switches: the influence of the change of the nanotube-spiropyran distanceP Bluemmel, A Setaro, C Maity, S Hecht and S Reich Carbon nanotubes as substrates for molecular spiropyran-based switchesE Malic, A Setaro, P Bluemmel, Carlos F Sanz-Navarro, Pablo Ordejón, S Reich and A Knorr Ultrafast dynamics of dithienylethenes differently linked to the surface of TiO2 nanoparticlesLars Dworak, Marc Zastrow, Gehad Zeyat, Karola Rück-Braun and Josef Wachtveitl Switching the electronic properties of Co-octaethylporphyrin molecules on oxygen-covered Ni films by NO adsorptionC F Hermanns, M Bernien, A Krüger, J Miguel and W Kuch STM-switching of organic molecules on semiconductor surfaces: an above threshold density matrix model for 1,5 cyclooctadiene on Si(100)K Zenichowski, Ch Nacci, S Fölsch, J Dokić, T Klamroth and P Saalfrank A switch based on self-assembled thymineFatih Kalkan, Michael Mehlhorn and Karina Morgenstern The growth and electronic structure of azobenzene-based functional molecules on layered crystalsJ Iwicki, E Ludwig, J Buck, M Kalläne, F Köhler, R Herges, L Kipp and K Rossnagel Voltage-dependent conductance states of a single-molecule junctionY F Wang, N Néel, J Kröger, H Vázquez, M Brandbyge, B Wang and R Berndt Molecules with multiple switching units on a Au(111) surface: self-organization and single-molecule manipulationJohannes Mielke, Sofia Selvanathan, Maike Peters, Jutta Schwarz, Stefan Hecht and Leonhard Grill Preparing and regulating a bi-stable molecular switch by atomic manipulationS Sakulsermsuk, R E Palmer and P A Sloan Mixed self

  7. Application of advanced 100-kV EB writer EB-X3 for 100-nm node x-ray mask fabrication

    Science.gov (United States)

    Watanabe, Hiroshi; Nakayama, Yoshinori; Tsuboi, Shinji; Ezaki, Mizunori; Aoyama, Hajime; Matsui, Yasuji; Morosawa, Tetsuo; Oda, Masatoshi

    2001-08-01

    Most important issues in a precise X-ray mask fabrication are the mask materials and EB writing to achieve good accuracy in critical dimension (CD) control and image placement (IP). However, 1-to-1 X-ray mask is required severe accuracy in comparison with photo reticles. The following discussions focus on how to realize the precise IP accuracy. We installed and evaluated 100-kV electron-beam (EB) mask writer (EB-X3), and developed the writing process on a thin membrane. Key factors in accurate EB mask writing include not only EB positioning accuracy but also mask distortions caused by mask holding and the temperature change of the mask and a mask holder. This paper presents mask distortion characteristics due to the holding, temperature change, and then, good results of mask accuracy of 4-Gb dynamic random access memory (DRAM) test patterns (gate and contact layers) and 90 nm SRAM test patterns. In addition, we employed the advanced PAT method with 4-multi-pass writing that adequately compensates the process-induced mask distortion and the beam drift. These improvements resulted in IP accuracy of better than 10 nm (3(sigma) ), 100 nm CD uniformity within 8 nm (mean shift +/- 3(sigma) ) and the overlay accuracy within 10 nm for 4-Gb gate and contact layers with a 24 mm x 24 mm area on the X-ray membrane mask. These results demonstrate that we can actually fabricate precise X-ray membrane masks that meet our final target of IP accuracy corresponding to the 100 nm technology node.

  8. Sector Switching

    DEFF Research Database (Denmark)

    Newman, Carol; Rand, John; Tarp, Finn

    Much of the literature on industry evolution has found firm dynamics to be an important source of sector-level productivity growth. In this paper, we ask whether the delineation of entry and exit firms matters in assessing the impact of firm turnover. Using detailed firm level data from Vietnam......-level determinants of firm exit and switching, which need to be carefully considered in the search for effective policy...

  9. Sector Switching

    DEFF Research Database (Denmark)

    Newman, Carol; Rand, John; Tarp, Finn

    Much of the literature on industry evolution has found firm dynamics to be an important source of sector-level productivity growth. In this paper, we ask whether the delineation of entry and exit firms matters in assessing the impact of firm turnover. Using detailed firm level data from Vietnam, ......-level determinants of firm exit and switching, which need to be carefully considered in the search for effective policy...

  10. Switching station platform for applications worldwide; Schaltanlagenplattform fuer weltweite Einsaetze

    Energy Technology Data Exchange (ETDEWEB)

    Soens, Herbert [Siemens AG, Erlangen (Germany). Energy Sector

    2011-03-15

    The air-insulated medium-voltage power switching station NX-Air was first presented at the 1998 Hanover Fair. The range of variations in terms of rated voltage and rated short-circuit current was continuously expanded during the past few years. Now, Siemens introduced the new NX-Air concept as a platform switching stations for global applications in its production sites worldwide.

  11. Design of a switched reluctance generator

    Energy Technology Data Exchange (ETDEWEB)

    Heese, T.; Pyrhoenen, J.

    1996-12-31

    This report presents the design of a low voltage switched reluctance generator for variable speed applications showing the design of its construction and commutation unit. For the realisation of the control system the control strategy is presented. The principle and the theory of switched reluctance generators are described in this context. Also an overview of existing generator technology for these applications is given. The results gained suggest that switched reluctance machines can also advantageously be used as generators if the generating operation is considered within the design process. Compared with the existing technology a higher output power and efficiency is reached over the whole speed range. (orig.)

  12. Single photon detection and localization accuracy with an ebCMOS camera

    Science.gov (United States)

    Cajgfinger, T.; Dominjon, A.; Barbier, R.

    2015-07-01

    The CMOS sensor technologies evolve very fast and offer today very promising solutions to existing issues facing by imaging camera systems. CMOS sensors are very attractive for fast and sensitive imaging thanks to their low pixel noise (1e-) and their possibility of backside illumination. The ebCMOS group of IPNL has produced a camera system dedicated to Low Light Level detection and based on a 640 kPixels ebCMOS with its acquisition system. After reminding the principle of detection of an ebCMOS and the characteristics of our prototype, we confront our camera to other imaging systems. We compare the identification efficiency and the localization accuracy of a point source by four different photo-detection devices: the scientific CMOS (sCMOS), the Charge Coupled Device (CDD), the Electron Multiplying CCD (emCCD) and the Electron Bombarded CMOS (ebCMOS). Our ebCMOS camera is able to identify a single photon source in less than 10 ms with a localization accuracy better than 1 μm. We report as well efficiency measurement and the false positive identification of the ebCMOS camera by identifying more than hundreds of single photon sources in parallel. About 700 spots are identified with a detection efficiency higher than 90% and a false positive percentage lower than 5. With these measurements, we show that our target tracking algorithm can be implemented in real time at 500 frames per second under a photon flux of the order of 8000 photons per frame. These results demonstrate that the ebCMOS camera concept with its single photon detection and target tracking algorithm is one of the best devices for low light and fast applications such as bioluminescence imaging, quantum dots tracking or adaptive optics.

  13. Single photon detection and localization accuracy with an ebCMOS camera

    Energy Technology Data Exchange (ETDEWEB)

    Cajgfinger, T. [CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne F-69622 (France); Dominjon, A., E-mail: agnes.dominjon@nao.ac.jp [Université de Lyon, Université de Lyon 1, Lyon 69003 France. (France); Barbier, R. [CNRS/IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne F-69622 (France); Université de Lyon, Université de Lyon 1, Lyon 69003 France. (France)

    2015-07-01

    The CMOS sensor technologies evolve very fast and offer today very promising solutions to existing issues facing by imaging camera systems. CMOS sensors are very attractive for fast and sensitive imaging thanks to their low pixel noise (1e-) and their possibility of backside illumination. The ebCMOS group of IPNL has produced a camera system dedicated to Low Light Level detection and based on a 640 kPixels ebCMOS with its acquisition system. After reminding the principle of detection of an ebCMOS and the characteristics of our prototype, we confront our camera to other imaging systems. We compare the identification efficiency and the localization accuracy of a point source by four different photo-detection devices: the scientific CMOS (sCMOS), the Charge Coupled Device (CDD), the Electron Multiplying CCD (emCCD) and the Electron Bombarded CMOS (ebCMOS). Our ebCMOS camera is able to identify a single photon source in less than 10 ms with a localization accuracy better than 1 µm. We report as well efficiency measurement and the false positive identification of the ebCMOS camera by identifying more than hundreds of single photon sources in parallel. About 700 spots are identified with a detection efficiency higher than 90% and a false positive percentage lower than 5. With these measurements, we show that our target tracking algorithm can be implemented in real time at 500 frames per second under a photon flux of the order of 8000 photons per frame. These results demonstrate that the ebCMOS camera concept with its single photon detection and target tracking algorithm is one of the best devices for low light and fast applications such as bioluminescence imaging, quantum dots tracking or adaptive optics.

  14. An interleaved five-level boost converter with voltage-balance control

    DEFF Research Database (Denmark)

    Chen, Jianfei; Hou, Shiying; Deng, Fujin

    2016-01-01

    This paper proposes an interleaved five-level boost converter based on switched-capacitor network. Operating principle of the converter under CCM mode is analyzed. High voltage gain, low component stress, small input current ripple, and self-balance function for capacitor voltages in the switched......-capacitor networks are achieved. Besides, a three-loop control strategy including outer voltage loop, inner current loop and voltage-balance loop has been researched to achieve good performances and voltage-balance effect. Experimental study has been done to verify the correctness and feasibility of the proposed...... converter and control strategy....

  15. 动态电压调节开关变换器的定频导通时间控制%Constant frequency turn-on time control of dynamic voltage scaling switching converters

    Institute of Scientific and Technical Information of China (English)

    徐杨军; 许建平; 王金平; 何圣仲

    2014-01-01

    对动态电压调节(Dynamic Voltage Scaling,DVS)开关变换器的定频导通时间(Constant Frequency Turn-On Time,CFOT)控制技术进行了研究,在恒定导通时间(Constant On-Time,COT)基础上,通过引入输入电压前馈和输出参考电压反馈环路,实现不同输入、输出电压条件下DVS开关变换器保持开关频率恒定.研究结果表明,CFOT控制不仅继承了传统COT控制环路设计简单、无需误差放大器及其相应的补偿网路、瞬态响应快的优点,而且消除了输入、输出电压变动对开关频率的影响.

  16. Vibration control via stiffness switching of magnetostrictive transducers

    Science.gov (United States)

    Scheidler, Justin J.; Asnani, Vivake M.; Dapino, Marcelo J.

    2016-04-01

    In this paper, a computational study is presented of structural vibration control that is realized by switching a magneto-strictive transducer between high and low stiffness states. Switching is accomplished by either changing the applied magnetic field with a voltage excitation or changing the shunt impedance on the transducer's coil (i.e., the magneto-strictive material's magnetic boundary condition). Switched-stiffness vibration control is simulated using a lumped mass supported by a damper and the magneto-strictive transducer (mount), which is represented by a nonlinear, electromechanical model. Free vibration of the mass is calculated while varying the mount's stiffness according to a reference switched-stiffness vibration control law. The results reveal that switching the magnetic field produces the desired change in stiffness, but also an undesired actuation force that can significantly degrade the vibration control. Hence, a modified switched-stiffness control law that accounts for the actuation force is proposed and implemented for voltage-controlled stiffness switching. The influence of the magneto-mechanical bias condition is also discussed. Voltage-controlled stiffness switching is found to introduce damping equivalent to a viscous damping factor up to about 0.13; this is shown to primarily result from active vibration reduction caused by the actuation force. The merit of magneto-strictive switched-stiffness vibration control is then quantified by comparing the results of voltage- and shunt-controlled stiffness switching to the performance of optimal magneto-strictive shunt damping. For the cases considered, optimal resistive shunt damping performed considerably better than both voltage- and shunt-controlled stiffness switching.

  17. Dynamical modeling and multi-period behavior analysis of voltage-mode bi-frequency controlled switching converter%电压型双频率控制开关变换器的动力学建模与多周期行为分析

    Institute of Scientific and Technical Information of China (English)

    吴松荣; 何圣仲; 许建平; 周国华; 王金平

    2013-01-01

    在断续导电模式下,建立了电压型双频率控制开关变换器的动力学模型,并推导了相应的特征值方程。根据动力学模型,采用分岔图研究了电路参数变化时变换器存在的边界碰撞分岔行为和周期2,周期3,周期4等多周期行为,结果表明:变换器经历了周期1态、多周期态、周期1态的分岔路由;周期态的转变均是由边界碰撞分岔引起的。根据特征值方程,采用Lyapunov指数研究了变换器的稳定性,结果表明:随着电路参数的变化, Lyapunov指数始终小于零,变换器一直工作于稳定的周期态,验证了电压型双频率控制开关变换器的周期3行为并不意味着变换器会必然发生混沌。通过电路仿真,分析了负载变化时变换器的时域波形、相轨图和频谱图,验证了动力学模型的可行性和理论分析的正确性。实验结果验证了文中的仿真结果。%A dynamical model is proposed and the corresponding characteristic aligns are derived for voltage-mode bi-frequency controlled switching converter operating in discontinuous conduction mode. According to the dynamical model, the border-collision bifurcation and multi-period behaviors, such as period-2, period-3, period-4, and so on, are studied using bifurcation diagrams as the circuit parameters are varied. It is found that the converter behaves along the bifurcation route of period-1, multi-period, and period-1, and the change of period state is induced by border-collision bifurcation. Based on the characteristic equation, the converter stability is investigated by the Lyapunov exponent. It is shown that Lyapunov exponent is always smaller than zero with the variation of circuit parameters and the converter operates in stable period state all the time. Also, it is validated that period-3 behavior of voltage-mode bi-frequency controlled switching converter does not predicate its inevitable chaos. Time-domain waveforms, phase portraits, and

  18. Crystal micromorphologies and forming voltage effect on resistance switching behaviors in Ti/Pr(Sr{sub 0.1}Ca{sub 0.9}){sub 2}Mn{sub 2}O{sub 7}/Pt devices

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yuchen; Song, Liwei; Hua, Lifang; Cai, Wenhui; Chen, Wei [College of Physics Science & Information Engineering, Hebei Normal University, Shijiazhuang 050024 (China); Key Laboratory of Advanced Films of Hebei Province, Shijiazhuang 050024 (China); Zhao, Xu, E-mail: xzhao@hebtu.edu.cn [College of Physics Science & Information Engineering, Hebei Normal University, Shijiazhuang 050024 (China); Key Laboratory of Advanced Films of Hebei Province, Shijiazhuang 050024 (China)

    2015-10-15

    Two Pr(Sr{sub 0.1}Ca{sub 0.9}){sub 2}Mn{sub 2}O{sub 7} (PSCMO)-based devices (Ti/PSCMO-1/Pt and Ti/PSCMO-2/Pt) have been prepared by pulsed laser deposition, and the micromorphology of the films can be controlled through the different deposition condition. PSCMO-1 film with a smaller grain size grows with a near-random arrangement, whereas columnar grains with a larger grain size appear in the Ti/PSCMO-2/Pt device. The I–V curves in Ti/PSCMO-2/Pt device show the higher resistance ratio and larger hysteresis than that in the Ti/PSCMO-1/Pt device without forming process. The electron transport property in the PSCMO-2 film shows the higher resistance and metal behavior in room temperature. By fitting the I–V curves, we found that the conduction process in Ti/PSCMO-1/Pt device is dominated by Schottky barrier mechanism, but the conduction behavior in Ti/PSCMO-2/Pt device are dominated by trap-charged space-charge-limited current (SCLC) mechanism. Interesting, after a forming process, the Ti/PSCMO-1/Pt device also displays the higher resistance ratio and larger hysteresis, which can be explained by SCLC mechanism. Our results suggest that the crystal micromorphology and grain size may play a critical role in oxygen vacancy movement, and result in the transformation of resistance switching along with a higher resistance ratio and larger hysteresis in the Ti/PSCMO-2/Pt device. - Highlights: • Two different Pr(Sr{sub 0.1}Ca{sub 0.9}){sub 2}Mn{sub 2}O{sub 7}-based devices have been prepared. • The device with larger grain and columnar arrangement shows higher resistance ratio. • Crystal morphologies and grain size play critical role in oxygen vacancy movement.

  19. A solid-state dielectric elastomer switch for soft logic

    Science.gov (United States)

    Chau, Nixon; Slipher, Geoffrey A.; O'Brien, Benjamin M.; Mrozek, Randy A.; Anderson, Iain A.

    2016-03-01

    In this paper, we describe a stretchable solid-state electronic switching material that operates at high voltage potentials, as well as a switch material benchmarking technique that utilizes a modular dielectric elastomer (artificial muscle) ring oscillator. The solid-state switching material was integrated into our oscillator, which self-started after 16 s and performed 5 oscillations at a frequency of 1.05 Hz with 3.25 kV DC input. Our materials-by-design approach for the nickel filled polydimethylsiloxane based switch has resulted in significant improvements over previous carbon grease-based switches in four key areas, namely, sharpness of switching behavior upon applied stretch, magnitude of electrical resistance change, ease of manufacture, and production rate. Switch lifetime was demonstrated to be in the range of tens to hundreds of cycles with the current process. An interesting and potentially useful strain-based switching hysteresis behavior is also presented.

  20. A solid-state dielectric elastomer switch for soft logic

    Energy Technology Data Exchange (ETDEWEB)

    Chau, Nixon [Biomimetics Laboratory, Auckland Bioengineering Institute, The University of Auckland, Level 6, 70 Symonds Street, Auckland 1010 (New Zealand); Slipher, Geoffrey A., E-mail: geoffrey.a.slipher.civ@mail.mil; Mrozek, Randy A. [U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States); O' Brien, Benjamin M. [StretchSense, Ltd., 27 Walls Rd., Penrose, Auckland 1061 (New Zealand); Anderson, Iain A. [Biomimetics Laboratory, Auckland Bioengineering Institute, The University of Auckland, Level 6, 70 Symonds Street, Auckland 1010 (New Zealand); StretchSense, Ltd., 27 Walls Rd., Penrose, Auckland 1061 (New Zealand); Department of Engineering Science, School of Engineering, The University of Auckland, Level 3, 70 Symonds Street, Auckland 1010 (New Zealand)

    2016-03-07

    In this paper, we describe a stretchable solid-state electronic switching material that operates at high voltage potentials, as well as a switch material benchmarking technique that utilizes a modular dielectric elastomer (artificial muscle) ring oscillator. The solid-state switching material was integrated into our oscillator, which self-started after 16 s and performed 5 oscillations at a frequency of 1.05 Hz with 3.25 kV DC input. Our materials-by-design approach for the nickel filled polydimethylsiloxane based switch has resulted in significant improvements over previous carbon grease-based switches in four key areas, namely, sharpness of switching behavior upon applied stretch, magnitude of electrical resistance change, ease of manufacture, and production rate. Switch lifetime was demonstrated to be in the range of tens to hundreds of cycles with the current process. An interesting and potentially useful strain-based switching hysteresis behavior is also presented.

  1. Performance of Three-Arm Ac Automatic Voltage Regulator

    Directory of Open Access Journals (Sweden)

    T. Papinaidu

    2014-04-01

    Full Text Available In this paper the design and simulation of automatic voltage regulator (AVR is proposed. The AVR provides voltage buck and boost capability to eliminate power problems created by under voltage or over voltage fluctuations. It also protects against minor and severe spikes and surges that comprise over 80% of power problems. Over heating of components due to voltage swell is also avoided by using AVR. The switching losses are also reduced as only one arm among three arms is maintained at higher power frequencies depending on mode of operation. Moreover, there is no need to use large capacitor as a result the overall size of converter is also reduced. Hence, the output voltage of the AVR can be maintained at the specified voltage. Hence, the AVR is cost can be reduced, and the efficiency of the power convertor can be extended.

  2. A nanoscale piezoelectric transformer for low-voltage transistors.

    Science.gov (United States)

    Agarwal, Sapan; Yablonovitch, Eli

    2014-11-12

    A novel piezoelectric voltage transformer for low-voltage transistors is proposed. Placing a piezoelectric transformer on the gate of a field-effect transistor results in the piezoelectric transformer field-effect transistor that can switch at significantly lower voltages than a conventional transistor. The piezoelectric transformer operates by using one piezoelectric to squeeze another piezoelectric to generate a higher output voltage than the input voltage. Multiple piezoelectrics can be used to squeeze a single piezoelectric layer to generate an even higher voltage amplification. Coupled electrical and mechanical modeling in COMSOL predicts a 12.5× voltage amplification for a six-layer piezoelectric transformer. This would lead to more than a 150× reduction in the power needed for communications.

  3. STUDIES ON TiCl4/Mg (Oet)2/EB SUPPORTED CATALYSTS FOR PROPYLENE POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    XIAO Shijing; LU Honglan; ZHANG Minghui

    1990-01-01

    The supported catalysts for propylene polymerization were prepared by milling Mg (OEt)2 with EB (ethylbenzoate) and treating with TiCl4 solution. When TiCl4/(Mg (OEt)2/EB) (mol.) ratio was increased, decrease in contents of -OEt and Ti of the catalysts was observed, while the content of EB increased. It is proved by analyses of IR, X-ray and XPS that during co-milling Mg(OEt)2with EB no reactions have taken place. But after treatment with TiCl4 solution, Mg (OEt)2 converts into MgCl2 and EB coordinates on the resulting MgCl2 carrier, a surface complex forms.The activity of catalysts,isotacticityand vicosimetric molecular weight of polypropylene increase with the decrease of the content of ethoxyl group. The kinetic curves of propene polymerization obtained with present catalysts system display decay curves. It is found from the triad tacticity calculated from the expanded spectra of methyl carbon region that, ethoxyl group in catalyst has an effect on the configuration of polymer chain.

  4. PSD-95 alters microtubule dynamics via an association with EB3

    Science.gov (United States)

    Sweet, Eric S.; Previtera, Michelle L.; Fernández, Jose R.; Charych, Erik I.; Tseng, Chia-Yi; Kwon, Munjin; Starovoytov, Valentin; Zheng, James Q.; Firestein, Bonnie L.

    2011-01-01

    Little is known about how the neuronal cytoskeleton is regulated when a dendrite decides whether to branch or not. Previously, we reported that postsynaptic density protein 95 (PSD-95) acts as a stop signal for dendrite branching. It is yet to be elucidated how PSD-95 affects the cytoskeleton and how this regulation relates to the dendritic arbor. Here, we show that the SH3 (src homology 3) domain of PSD-95 interacts with a proline-rich region within the microtubule end-binding protein EB3. Overexpression of PSD-95 or mutant EB3 results in a decreased lifetime of EB3 comets in dendrites. In line with these data, transfected rat neurons show that overexpression of PSD-95 results in less organized microtubules at dendritic branch points and decreased dendritogensis. The interaction between PSD-95 and EB3 elucidates a function for a novel region of EB3 and provides a new and important mechanism for the regulation of microtubules in determining dendritic morphology. PMID:21248129

  5. International Collaborations on Engineered Barrier Systems: Brief Overview of SKB-EBS Activities.

    Energy Technology Data Exchange (ETDEWEB)

    Jove-Colon, Carlos F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-10-01

    Research collaborations with international partners on the behavior and performance of engineered barrier systems (EBS) are an important aspect of the DOE-NE Used Fuel Disposition Campaign strategy in the evaluation of disposal design concepts. These international partnerships are a cost-effective way of engaging in key R&D activities with common goals resulting in effective scientific knowledge exchanges thus enhancing existing and future research programs in the USA. This report provides a brief description of the activities covered by the Swedish Nuclear Fuel and Waste Management Company (SKB) EBS Task Force (TF) (referred hereafter as SKB EBS TF) and potential future directions for engagement of the DOE-NE UFDC program in relevant R&D activities. Emphasis is given to SKB EBS TF activities that are still ongoing and aligned to the UFDC R&D program. This include utilization of data collected in the bentonite rock interaction experiment (BRIE) and data sets from benchmark experiments produced by the chemistry or “C” part of the SKB EBS TF. Potential applications of information generated by this program include comparisons/tests between model and data (e.g., reactive diffusion), development and implementation of coupled-process models (e.g., HM), and code/model benchmarking.

  6. Isolation and characterization of Bacillus subtilis EB-28, an endophytic bacterium strain displaying biocontrol activity against Botrytis cinerea Pers

    Institute of Scientific and Technical Information of China (English)

    Shutong WANG; Tongle HU; Yanling JIAO; Jianjian WEI; Keqiang CAO

    2009-01-01

    The fungal pathogen Botrytis cinerea Pers. causes severe rotting on tomato fruits during storage and shelf life. As a biological control agent, endophytic bacterium was regarded as an effective alternative to chemical control. Out of 238 endophytic bacterial isolates, three strains (EB-15, EB-28, and EB-122) isolated from Lycopersicum esculentum Mill., Speranskia tuberculata (Bge.) Baill, and Dictamnus dasycarpus Turcz. respectively were found to be strongly antagonistic to the pathogen in vitro and were selected for further in vivo tests. One endophytic bacterium strain, encoded EB-28, was selected from the three in vivo tested isolates. The inhibitive rate of EB-28 reached 71.1% in vitro and 52.4% in vivo. EB-28 was identified as Bacillus subtilis according to its morphological, physiological, and biochemical characteristics and 16S rDNA sequence analysis.

  7. Energy-aware Supply Voltage and Body Biasing Voltage Scheduling Algorithm for Real-time Distributed Systems

    Institute of Scientific and Technical Information of China (English)

    SUYajuan; WEIShaojun

    2005-01-01

    Technique of energy minimization by combining Dynamic voltage scheduling (DVS) and Adaptive body biasing voltage (ABB) method for distributed realtime system at design level is proposed. First, a simplified energy optimizing model is illustrated where the supply voltage or body biasing voltage is kept as constant according to each separated frequency region, thus calculation of exceeding equation is avoided. Divergence of simplified and analytic model within 5% indicates the accuracy of this model. Based on it, the proposed approach named LEVVS (Low energy supply voltage and body biasing voltage scheduling algorithm) explores space of minimizing energy consumption by finding optimal trade-off between dynamic and static energy. The corresponding optimal supply voltage and body biasing voltage are determined by an iterative method in which the supply voltage and body biasing voltage of tasks are adjusted according to the value of energy latency differential coefficient of each task and slack time distribution of the system. Experiments show that using LEVVS approach, 51% more average energy reduction can be obtained than employing DVS method alone. Furthermore the effects of switch capacitance and global slack on the energy saving efficiency of LEVVS are investigated. The smaller the global slack or average switch capacitance is, the more the energy saving of LEVVS compared with DVS is.

  8. Resistance switching of electrodeposited cuprous oxide

    Science.gov (United States)

    Yazdanparast, Sanaz

    In this work, the resistance switching behavior of electrodeposited cuprous oxide (Cu2O) thin films in Au/Cu2O/top electrode (Pt, Au-Pd, Al) cells was studied. After an initial FORMING process, the fabricated cells show reversible switching between a low resistance state (16.6 O) and a high resistance state (0.4 x 106 O). Changing the resistance states in cuprous oxide films depends on the magnitude of the applied voltage which corresponds to unipolar resistance switching behavior of this material. The endurance and retention tests indicate a potential application of the fabricated cells for nonvolatile resistance switching random access memory (RRAM). The results suggest formation and rupture of one or several nanoscale copper filaments as the resistance switching mechanism in the cuprous oxide films. At high electric voltage in the as-deposited state of Au/Cu 2O/Au-Pd cell structure, the conduction behavior follows Poole-Frenkel emission. Various parameters, such as the compliance current, the cuprous oxide microstructure, the cuprous oxide thickness, top electrode area, and top electrode material, affect the resistance switching characteristics. The required FORMING voltage is higher for Au/Cu2O/Al cell compared with the Au/Cu2O/Pt which is related to the Schottky behavior of Al contact with Cu2O. Cu2O nanowires in Au-Pt/ Cu 2O/Au-Pt cell also show resistance switching behavior, indicating scalable potential of this cell for usage as RRAM. After an initial FORMING process under an electric field of 3 x 106 V/m, the Cu2O nanowire is switched to the LRS. During the FORMING process physical damages are observed in the cell, which may be caused by Joule heating and gas evolution.

  9. Ultra-compact Marx-type high-voltage generator

    Science.gov (United States)

    Goerz, David A.; Wilson, Michael J.

    2000-01-01

    An ultra-compact Marx-type high-voltage generator includes individual high-performance components that are closely coupled and integrated into an extremely compact assembly. In one embodiment, a repetitively-switched, ultra-compact Marx generator includes low-profile, annular-shaped, high-voltage, ceramic capacitors with contoured edges and coplanar extended electrodes used for primary energy storage; low-profile, low-inductance, high-voltage, pressurized gas switches with compact gas envelopes suitably designed to be integrated with the annular capacitors; feed-forward, high-voltage, ceramic capacitors attached across successive switch-capacitor-switch stages to couple the necessary energy forward to sufficiently overvoltage the spark gap of the next in-line switch; optimally shaped electrodes and insulator surfaces to reduce electric field stresses in the weakest regions where dissimilar materials meet, and to spread the fields more evenly throughout the dielectric materials, allowing them to operate closer to their intrinsic breakdown levels; and uses manufacturing and assembly methods to integrate the capacitors and switches into stages that can be arranged into a low-profile Marx generator.

  10. Transient Voltage Recorder

    Science.gov (United States)

    Medelius, Pedro J. (Inventor); Simpson, Howard J. (Inventor)

    2002-01-01

    A voltage transient recorder can detect lightning induced transient voltages. The recorder detects a lightning induced transient voltage and adjusts input amplifiers to accurately record transient voltage magnitudes. The recorder stores voltage data from numerous monitored channels, or devices. The data is time stamped and can be output in real time, or stored for later retrieval. The transient recorder, in one embodiment, includes an analog-to-digital converter and a voltage threshold detector. When an input voltage exceeds a pre-determined voltage threshold, the recorder stores the incoming voltage magnitude and time of arrival. The recorder also determines if its input amplifier circuits clip the incoming signal or if the incoming signal is too low. If the input data is clipped or too low, the recorder adjusts the gain of the amplifier circuits to accurately acquire subsequent components of the lightning induced transients.

  11. Improved multi-level capability in Si3N4-based resistive switching memory using continuous gradual reset switching

    Science.gov (United States)

    Kim, Sungjun; Park, Byung-Gook

    2017-01-01

    In this letter, we compare three different types of reset switching behavior in a bipolar resistive random-access memory (RRAM) system that is housed in a Ni/Si3N4/Si structure. The abrupt, step-like gradual and continuous gradual reset transitions are largely determined by the low-resistance state (LRS). For abrupt reset switching, the large conducting path shows ohmic behavior or has a weak nonlinear current-voltage (I-V) characteristics in the LRS. For gradual switching, including both the step-like and continuous reset types, trap-assisted direct tunneling is dominant in the low-voltage regime, while trap-assisted Fowler-Nordheim tunneling is dominant in the high-voltage regime, thus causing nonlinear I-V characteristics. More importantly, we evaluate the multi-level capabilities of the two different gradual switching types, including both step-like and continuous reset behavior, using identical and incremental voltage conditions. Finer control of the conductance level with good uniformity is achieved in continuous gradual reset switching when compared to that in step-like gradual reset switching. For continuous reset switching, a single conducting path, which initially has a tunneling gap, gradually responds to pulses with even and identical amplitudes, while for step-like reset switching, the multiple conducting paths only respond to incremental pulses to obtain effective multi-level states.

  12. Human Eb Peptide: Not just a By-product of Pre-pro-IGF1b Processing?

    Science.gov (United States)

    Durzyńska, J.; Wardziński, A.; Koczorowska, M.; Goździcka-Józefiak, A.; Barton, E. R.

    2015-01-01

    Several physiological activities have been assigned to E-peptides derived from pre-pro-insulin-like growth factor (IGF1) processing; however, the whole range of the E-peptides’ functions is still unknown. The objective of this study was to investigate human Eb peptide (hEb) in terms of its bioactivity, cellular localization, and intracellular trafficking using human cancer cells. Human Eb fused with red fluorescence protein (RFP) or green fluorescence protein (GFP) localizes strongly to nucleoli and to a lesser extent to nuclei of HeLa and U2-OS cells. Mutagenesis of hEb nucleolus localization sequence (NoLS) leads to its partial delocalization from nuclei and nucleoli to cytoplasm of transfected cells. Thus, NoLS is not sufficient for the hEb to be localized in nucleoli of the cells and a different mechanism may be involved in hEb targeting. A BrdU ELISA showed that the proliferation index of cells expressing hEb hybrid proteins increased up to 28 %. For comparison, the same assay was performed using HeLa cells treated extracellularly with synthetic hEb. A significant increase in the proliferation index was observed (41–58 % for concentrations ranging from 10–100 nM, respectively). Additionally, a cell migration assay was performed using stable U2-OS cell lines expressing hEb fused with RFP or RFP alone as a negative control. The migration index of hEb expressing cells was 38.3 % greater. The increase in cell proliferation index and in motile properties of hEb expressing cells demonstrate that hEb is more than a pre-pro-IGF1b processing product, and has intrinsic activity of biological significance. PMID:23335048

  13. Comparison of soft and hard-switching effiency in a three-level single phase 60kW dc-ac converter

    DEFF Research Database (Denmark)

    Munk-Nielsen, Stig; Teodorescu, Remus; Bech, Michael Møller;

    2003-01-01

    Efficiency measurements on a three-level single-phase soft-switched converter are presented and show a slightly improved efficiency compared with the hard-switched converter for output powers higher than 25 % of rated power. The resonant converter switches are Zero Voltage Switched (ZVS) and a si......Efficiency measurements on a three-level single-phase soft-switched converter are presented and show a slightly improved efficiency compared with the hard-switched converter for output powers higher than 25 % of rated power. The resonant converter switches are Zero Voltage Switched (ZVS...

  14. Chopper amplifier circuit with CMOS switches and amplifier FETs

    NARCIS (Netherlands)

    Huijsing, J.H.; Bakker, A.

    1997-01-01

    Abstract of NL 1001231 (C2) The input voltage is fed to the inputs of an operational amplifier via a chopping reversal switchThe CMOS operational amplifier has a current source and a current mirror. The operational amplifier output is fed to an output circuit. The possible offset voltage is supp

  15. Observations and implications of gap closure in plasma opening switch operation

    Science.gov (United States)

    Goyer, John R.; Kortbawi, David

    1994-09-01

    Plasma opening switches are believed to develop voltage through opening and magnetically insulating a gap formed in plasma injected between two conducting electrodes. Data will be presented to show that a relatively simple assumption about the behavior of this gap suffices to describe the overall operation of the switch. Specifically, the observed increase, then decrease, of operational voltage as a function of conduction time can be accounted for by the switch gap linearly decreasing with conduction time, while the conducted current increases. In addition to presentation of data to demonstrate this collapse, analysis is performed to couple the gap history to the voltage predicted for the switch, and to optimize this latter quantity.

  16. GPS navigation based on ADXL345 and EB3631%ADXL345与EB3631在GPS导航中的应用

    Institute of Scientific and Technical Information of China (English)

    王波

    2014-01-01

    为实现用户到目标点的距离测量和方向控制,设计并实现了基于加速度传感器ADXL345和EB3631的GPS模块的实时导航系统.系统选用EB3631搭建GPS模块,通过串口与ATMEGA644P控制器通信采集GPS定位信息;采用加速度传感器ADXL345,通过ⅡC协议与控制器通信实现位移测量.在0m-500m范围内,对系统稳定性和准确性的反复测试,最终实现了相对误差在10%以内的准确度较高的导航系统.

  17. Design of DC-contact RF MEMS switch with temperature stability

    Directory of Open Access Journals (Sweden)

    Junfeng Sun

    2015-04-01

    Full Text Available In order to improve the temperature stability of DC-contact RF MEMS switch, a thermal buckle-beam structure is implemented. The stability of the switch pull-in voltage versus temperature is not only improved, but also the impact of stress and stress gradient on the drive voltage is suppressed. Test results show that the switch pull-in voltage is less sensitive to temperature between -20 °C and 100 °C. The variable rate of pull-in voltage to temperature is about -120 mV/°C. The RF performance of the switch is stable, and the isolation is almost independent of temperature. After being annealed at 280 °C for 12 hours, our switch samples, which are suitable for packaging, have less than 1.5% change in the rate of pull-in voltage.

  18. Voltage Balancing Method on Expert System for 51-Level MMC in High Voltage Direct Current Transmission

    Directory of Open Access Journals (Sweden)

    Yong Chen

    2016-01-01

    Full Text Available The Modular Multilevel Converters (MMC have been a spotlight for the high voltage and high power transmission systems. In the VSC-HVDC (High Voltage Direct Current based on Voltage Source Converter transmission system, the energy of DC link is stored in the distributed capacitors, and the difference of capacitors in parameters and charge rates causes capacitor voltage balance which affects the safety and stability of HVDC system. A method of MMC based on the expert system for reducing the frequency of the submodules (SMs of the IGBT switching frequency is proposed. Firstly, MMC with 51 levels for HVDC is designed. Secondly, the nearest level control (NLC for 51-level MMC is introduced. Thirdly, a modified capacitor voltage balancing method based on expert system for MMC-based HVDC transmission system is proposed. Finally, a simulation platform for 51-level Modular Multilevel Converter is constructed by using MATLAB/SIMULINK. The results indicate that the strategy proposed reduces the switching frequency on the premise of keeping submodule voltage basically identical, which greatly reduces the power losses for MMC-HVDC system.

  19. Characteristics of SF6 Switch with a Small Gap under High Pressure and Nanosecond Pulse

    Institute of Scientific and Technical Information of China (English)

    TANG Junping; QIU Aici; BO Haiwang; DONG Qinxiao; HE Xiaoping

    2009-01-01

    Structural design and tests on the characteristics of the SFs gas switch with a small gap are presented. This kind of switch often works under high pressure and nanosecond pulse for getting pulse with faster risetime. The breakdown voltage and breakdown delay of a number of switches with different geometries, gas pressures and pulse waveforms were investigated.Experimental results suggested that the breakdown voltage increases linearly with the gas pressure,and the breakdown delay decreases with an increase in the gas pressure and a reduction in the gap distance of the switch under the same applied pulse. By using this kind of switch with a gap of 3 mm as a peaking switch, a pulse generator can provide an output voltage with a peak voltage of 300 kV and a risetime of 3 ns on a resistance load of 150 Ω.

  20. A Pulsed Power Supply with Sag Compensation using Controlled Gradational Voltage

    Science.gov (United States)

    Suzuki, Akihiro; Yamada, Masaki; Tashiro, Shojirou; Iwata, Akihiko

    A pulsed power supply with sag compensation using controlled gradational voltage to increase the flatness of output waveforms has been developed.The sag compensation circuit consists of compensation units connected in series. Each compensation unit consists of capacitances, diodes, and semiconductor switches. The capacitances of each unit are charged with different voltages by 2n (V0, 2V0, 4V0, ···). The compensation voltages, which has 2n-1 steps, is generated by switching the semiconductor switches of each unit in a binary sequence. Using this method, compensation voltage waveforms up to 6.2kV with 31 steps can be obtained with 5 compensation units. The sag compensation circuit has been adapted to a direct switch type pulsed power supply, which generates 7kV pulsed voltage with a pulse width of 700μs, thus realizing sag compensation.

  1. Plasma opening switch with extrinsic magnetic field

    CERN Document Server

    Dolgachev, G; Maslennikov, D

    2001-01-01

    Summary form only given, as follows. We have demonstrated in series of experiments that plasma opening switch (POS) switching voltage (UPOS) is defined by energy density (w) deposited in the POS plasma. If we then consider a plasma erosion mainly responsible for the effect of POS switching (the erosion effect could be described by Hall or Child-Langmuir models) the energy density (w) could be measured as a function of a system "macro-parameter" such as the initial charging voltage of the capacity storage system (the Marx pulsed voltage generator) UMarx. The POS voltage in this case could be given by UPOS"aw=aUMarx4/7, where a is a constant. This report demonstrates that for the high-impedance POS which has limited charge density transferred through the POS plasma a"2.5 (MV3/7) with no external magnetic field applied. The use of the extrinsic magnetic field allows to increase a up to 3.6 (MV3/7) and to achieve higher voltages at the opening phase - UPOS=3.6UMarx4/7. To verify this approach set of experimental ...

  2. Three New Pierce's Disease Pathogenicity Effectors Identified Using Xylella fastidiosa Biocontrol Strain EB92-1.

    Directory of Open Access Journals (Sweden)

    Shujian Zhang

    Full Text Available Xylella fastidiosa (X. fastidiosa infects a wide range of plant hosts and causes economically serious diseases, including Pierce's Disease (PD of grapevines. X. fastidiosa biocontrol strain EB92-1 was isolated from elderberry and is infectious and persistent in grapevines but causes only very slight symptoms under ideal conditions. The draft genome of EB92-1 revealed that it appeared to be missing genes encoding 10 potential PD pathogenicity effectors found in Temecula1. Subsequent PCR and sequencing analyses confirmed that EB92-1 was missing the following predicted effectors found in Temecula1: two type II secreted enzymes, including a lipase (LipA; PD1703 and a serine protease (PD0956; two identical genes encoding proteins similar to Zonula occludens toxins (Zot; PD0915 and PD0928, and at least one relatively short, hemagglutinin-like protein (PD0986. Leaves of tobacco and citrus inoculated with cell-free, crude protein extracts of E. coli BL21(DE3 overexpressing PD1703 exhibited a hypersensitive response (HR in less than 24 hours. When cloned into shuttle vector pBBR1MCS-5, PD1703 conferred strong secreted lipase activity to Xanthomonas citri, E. coli and X. fastidiosa EB92-1 in plate assays. EB92-1/PD1703 transformants also showed significantly increased disease symptoms on grapevines, characteristic of PD. Genes predicted to encode PD0928 (Zot and a PD0986 (hemagglutinin were also cloned into pBBR1MCS-5 and moved into EB92-1; both transformants also showed significantly increased symptoms on V. vinifera vines, characteristic of PD. Together, these results reveal that PD effectors include at least a lipase, two Zot-like toxins and a possibly redundant hemagglutinin, none of which are necessary for parasitic survival of X. fastidiosa populations in grapevines or elderberry.

  3. Superconducting switch pack

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, V.C.; Wollan, J.J.

    1990-07-24

    This patent describes a superconducting switch pack at least one switch element. The switch element including a length of superconductive wire having a switching portion and two lead portions, the switching portion being between the lead portions; means for supporting the switching portion in a plane in a common mold; hardened resin means encapsulating the switching portion in the plane in a solid body; wherein the solid body has an exterior surface which is planar and substantially parallel with and spaced apart from the plane in which the switching portion is positioned. The exterior surface being exposed to the exterior of the switch pack and the resin means filling the space between the exterior surface and the plane of the switching portion so as to provide uninterrupted thermal communication between the plane of the switching portion and the exterior of the switch pack; and a heater element in thermal contact with the switching portion.

  4. EB 病毒 LMP2A 在胃癌研究中的进展%Research progress in EB virus LMP2A in gastric cancer

    Institute of Scientific and Technical Information of China (English)

    夏琳钦; 伍石华; 张志伟

    2016-01-01

    EB 病毒(EBV)是具有致瘤潜能的疱疹病毒,其编码的潜伏性膜蛋白2A(LMP2A)通过多条信号传导通路,参与上皮细胞的转化。 EB 病毒存在于胃癌组织中,在胃癌的发生和发展过程中发挥重要的作用。本文主要就 LMP2A 的结构、介导的信号传导通路与胃癌的关系进行综述。%Epstein-Barr virus is a herpes virus with tumorigenic potential, its encoded latent membrane protein-2A through multiple signaling pathways, involved in the transformation of epithelial cells. The EB virus exists in gastric cancer cells,in the process of the occurrence and development of gastric cancer play an important role. This article mainly reviews the structure of LMP2A, mediated signaling pathway and gastric cancer.

  5. Validade convergente do tipo de vivência (EB no teste de Zulliger/SC = Convergent validity evidence of the personality Style (EB in Z-test/SC

    Directory of Open Access Journals (Sweden)

    Villemor-Amaral, Anna Elisa de

    2012-01-01

    Full Text Available O Zulliger foi adaptado para o Sistema Compreensivo de Exner numa amostra brasileira, pois embora o Sistema Compreensivo tenha sido desenvolvido para codificação e interpretação do método de Rorschach, a semelhança entre as duas técnicas levou a supor que o Zulliger poderia se beneficiar das mesmas vantagens alcançadas para o Rorschach. Esse estudo tem por objetivo verificar evidências de validade convergente para a classificação do Tipo de Vivência (EB no Zulliger, por meio de correlações com o indicador EB do Rorschach. Selecionaram-se de um banco de dados 51 protocolos de adultos, de ambos os sexos, com idade, escolaridade e nível socioeconômicos variados. As pessoas responderam a técnica de Zulliger e do Rorschach em dias consecutivos, alternando-se a ordem de aplicação das técnicas. Os resultados indicaram correlações significativas, mas apontam à necessidade de estabelecer novas proporções das variáveis que compõe o EB para a técnica de Zulliger

  6. Single-photon sensitive fast ebCMOS camera system for multiple-target tracking of single fluorophores: application to nano-biophotonics

    Science.gov (United States)

    Cajgfinger, Thomas; Chabanat, Eric; Dominjon, Agnes; Doan, Quang T.; Guerin, Cyrille; Houles, Julien; Barbier, Remi

    2011-03-01

    Nano-biophotonics applications will benefit from new fluorescent microscopy methods based essentially on super-resolution techniques (beyond the diffraction limit) on large biological structures (membranes) with fast frame rate (1000 Hz). This trend tends to push the photon detectors to the single-photon counting regime and the camera acquisition system to real time dynamic multiple-target tracing. The LUSIPHER prototype presented in this paper aims to give a different approach than those of Electron Multiplied CCD (EMCCD) technology and try to answer to the stringent demands of the new nano-biophotonics imaging techniques. The electron bombarded CMOS (ebCMOS) device has the potential to respond to this challenge, thanks to the linear gain of the accelerating high voltage of the photo-cathode, to the possible ultra fast frame rate of CMOS sensors and to the single-photon sensitivity. We produced a camera system based on a 640 kPixels ebCMOS with its acquisition system. The proof of concept for single-photon based tracking for multiple single-emitters is the main result of this paper.

  7. Effect of UV/EB radiation dosages on the properties of nanocomposite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Nik Salleh, Nik Ghazali, E-mail: Nik_Ghazali@nuclearmalaysia.gov.m [Malaysian Nuclear Agency, Block 42, Radiation Curing and Synthesis Group, Bangi, 43000 Kajang, Selangor (Malaysia); Firdaus Yhaya, Mohd; Hassan, Azman; Abu Bakar, Aznizam; Mokhtar, Munirah [Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)

    2011-02-15

    The aim of this study was to compare the effects of ultraviolet (UV) and electron beam (EB) radiation on the properties of cured nanocomposite coatings. Surface hardness increased with increase in radiation dosages (number of passes) for all samples. This was due to the increase in crosslinking with increase in radiation dosage. Pendulum hardness, gel content, and thumb twist results were analyzed to choose appropriate curing dosage for both curing techniques. The selected dosages were then used to cure coatings for scratch and abrasion resistance tests. It was found that the UV curing produced coatings with better abrasion resistance, whereas EB curing was a more suitable approach for producing scratch resistance coatings.

  8. Locally-Actuated Graphene-Based Nano-Electro-Mechanical Switch

    Directory of Open Access Journals (Sweden)

    Jian Sun

    2016-07-01

    Full Text Available The graphene nano-electro-mechanical switches are promising components due to their outstanding switching performance. However, most of the reported devices suffered from a large actuation voltages, hindering them from the integration in the conventional complementary metal-oxide-semiconductor (CMOS circuit. In this work, we demonstrated the graphene nano-electro-mechanical switches with the local actuation electrode via conventional nanofabrication techniques. Both cantilever-type and double-clamped beam switches were fabricated. These devices exhibited the sharp switching, reversible operation cycles, high on/off ratio, and a low actuation voltage of below 5 V, which were compatible with the CMOS circuit requirements.

  9. Line Capacity Expansion and Transmission Switching in Power Systems With Large-Scale Wind Power

    DEFF Research Database (Denmark)

    Villumsen, Jonas Christoffer; Bronmo, Geir; Philpott, Andy B.

    2013-01-01

    of power generation. We allow for active switching of transmission elements to reduce congestion effects caused by Kirchhoff's voltage law. Results show that actively switching transmission lines may yield a better utilization of transmission networks with large-scale wind power and increase wind power...... penetration. Furthermore, it is shown that transmission switching is likely to affect the optimal line capacity expansion plan....

  10. Theoretical analysis of highly linear tunable filters using Switched-Resistor techniques

    NARCIS (Netherlands)

    Jiraseree-amornkun, Amorn; Jiraseree-Amornkun, A.; Worapishet, Apisak; Klumperink, Eric A.M.; Nauta, Bram; Surakampontorn, Wanlop

    2008-01-01

    Abstract—In this paper, an in-depth analysis of switched-resistor (S-R) techniques for implementing low-voltage low-distortion tunable active-RC filters is presented. The S-R techniques make use of switch(es) with duty-cycle-controlled clock(s) to achieve tunability of the effective resistance and,

  11. Mixed voltage VLSI design

    Science.gov (United States)

    Panwar, Ramesh; Rennels, David; Alkalaj, Leon

    1993-01-01

    A technique for minimizing the power dissipated in a Very Large Scale Integration (VLSI) chip by lowering the operating voltage without any significant penalty in the chip throughput even though low voltage operation results in slower circuits. Since the overall throughput of a VLSI chip depends on the speed of the critical path(s) in the chip, it may be possible to sustain the throughput rates attained at higher voltages by operating the circuits in the critical path(s) with a high voltage while operating the other circuits with a lower voltage to minimize the power dissipation. The interface between the gates which operate at different voltages is crucial for low power dissipation since the interface may possibly have high static current dissipation thus negating the gains of the low voltage operation. The design of a voltage level translator which does the interface between the low voltage and high voltage circuits without any significant static dissipation is presented. Then, the results of the mixed voltage design using a greedy algorithm on three chips for various operating voltages are presented.

  12. 基于分形理论的低压断路器三相合闸同期性振动信号特征分析%Vibration signal feature analysis of switching synchronization for low voltage circuit breaker based on fractal theory

    Institute of Scientific and Technical Information of China (English)

    石敦义; 缪希仁; 郭谋发

    2014-01-01

    在综述现有断路器机械故障振动信号研究方法的基础上,提出了一种经验模态分解( EMD)和分形理论相结合的方法用于提取低压断路器振动信号的特征量,并以典型的三相合闸不同期性低压断路器故障为对象,研究了EMD结合分形维数的故障振动信号特征分析,且给出以分形维数均方根作为故障特征量的实验仿真数据结果。首先,利用EMD方法对低压断路器的振动信号进行分解,得到若干个本征模态函数( IMF);其次,对振动信号以及各IMF分量求分形维数及其均方根,作为低压断路器振动信号的特征量。通过对低压断路器三相合闸不同期性模拟故障振动信号处理,对比其不同状态下的分形维数及其均方根的变化规律,表明该方法不仅可作为低压断路器三相同期性故障诊断的判据,且可应用于断路器其他各类机械故障的振动信号特征的提取分析。%By reviewing the existing methods for mechanical fault vibration signal of circuit breaker, a method that combines EMD ( Empirical Mode Decomposition) with fractal theory is presented for extracting feature value from vibration signal of low voltage circuit breaker. Based on the typical object of low voltage circuit breaker for three⁃phases switching asynchronism, not only the fault vibration signal feature is analyzed by the method of EMD com⁃bined with fractal dimension, also the fault feature value of experimental and simulation data is provided with the root⁃mean⁃square of fractal dimension. Firstly, EMD is used to decompose the vibration signal into a number of in⁃trinsic mode functions ( IMF) . Secondly, the root⁃mean⁃square of fractal dimension is calculated for the vibration signal and it’ s every order IMF as the vibration signal feature value. Finally, the changing rule for the root⁃mean⁃square of fractal dimension to simulated failure vibration signals is

  13. Apparatus for Controlling Low Power Voltages in Space Based Processing Systems

    Science.gov (United States)

    Petrick, David J. (Inventor)

    2017-01-01

    A low power voltage control circuit for use in space missions includes a switching device coupled between an input voltage and an output voltage. The switching device includes a control input coupled to an enable signal, wherein the control input is configured to selectively turn the output voltage on or off based at least in part on the enable signal. A current monitoring circuit is coupled to the output voltage and configured to produce a trip signal, wherein the trip signal is active when a load current flowing through the switching device is determined to exceed a predetermined threshold and is inactive otherwise. The power voltage control circuit is constructed of space qualified components.

  14. Intrinsic nanofilamentation in resistive switching

    KAUST Repository

    Wu, Xing

    2013-03-15

    Resistive switching materials are promising candidates for nonvolatile data storage and reconfiguration of electronic applications. Intensive studies have been carried out on sandwiched metal-insulator-metal structures to achieve high density on-chip circuitry and non-volatile memory storage. Here, we provide insight into the mechanisms that govern highly reproducible controlled resistive switching via a nanofilament by using an asymmetric metal-insulator-semiconductor structure. In-situ transmission electron microscopy is used to study in real-time the physical structure and analyze the chemical composition of the nanofilament dynamically during resistive switching. Electrical stressing using an external voltage was applied by a tungsten tip to the nanosized devices having hafnium oxide (HfO2) as the insulator layer. The formation and rupture of the nanofilaments result in up to three orders of magnitude change in the current flowing through the dielectric during the switching event. Oxygen vacancies and metal atoms from the anode constitute the chemistry of the nanofilament.

  15. Wind Power Plant Voltage Stability Evaluation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, E.; Zhang, Y. C.

    2014-09-01

    Voltage stability refers to the ability of a power system to maintain steady voltages at all buses in the system after being subjected to a disturbance from a given initial operating condition. Voltage stability depends on a power system's ability to maintain and/or restore equilibrium between load demand and supply. Instability that may result occurs in the form of a progressive fall or rise of voltages of some buses. Possible outcomes of voltage instability are the loss of load in an area or tripped transmission lines and other elements by their protective systems, which may lead to cascading outages. The loss of synchronism of some generators may result from these outages or from operating conditions that violate a synchronous generator's field current limit, or in the case of variable speed wind turbine generator, the current limits of power switches. This paper investigates the impact of wind power plants on power system voltage stability by using synchrophasor measurements.

  16. Challenges for High Voltage Testing of UHV Equipment

    Institute of Scientific and Technical Information of China (English)

    Ernst Gockenbach

    2011-01-01

    The increase of voltage level for AC and DC transmission systems requires some changes in the high voltage testing for Ultra High Voltage (UHV) equipment. After a short description of the coordination work in the standard- ization bodies the requirements for UHV equipment are mentioned. The main points concerning high voltage testing of UHV equipment are the impulse shape of standard lightning impulse voltage, the evaluation of the test voltage for impulses with oscillations or overshoot near the peak and the time parameter of switching impulses. The linearity check of the measuring devices, the proximity effect, the wet tests and the atmospheric correction factors are further points to be discussed concerning testing of UHV equipment.

  17. 76 FR 59927 - Treatment of Aliens Whose Employment Creation Immigrant (EB-5) Petitions Were Approved After...

    Science.gov (United States)

    2011-09-28

    ... SECURITY 8 CFR Parts 216 and 245 RIN 1615-AA90 Treatment of Aliens Whose Employment Creation Immigrant (EB... applications and petitions of qualifying aliens whose employment-creation immigrant petitions were approved by...-273 Provisions C. Summary of the Adjudications Required by Public Law 107-273 III. Aliens Eligible To...

  18. 76 FR 61288 - Treatment of Aliens Whose Employment Creation Immigrant (EB-5) Petitions Were Approved After...

    Science.gov (United States)

    2011-10-04

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF HOMELAND SECURITY 8 CFR Parts 216 and 245 RIN 1615-AA90 Treatment of Aliens Whose Employment Creation Immigrant (EB... Homeland Security corrects an inadvertent error contained in the proposed rule titled Treatment of Aliens...

  19. Enhanced -->E*-->B drift effects in the TCV snowflake divertor

    NARCIS (Netherlands)

    G.P. Canal,; Lunt, T.; Reimerdes, H.; Duval, B. P.; Labit, B.; Vijvers, W. A. J.; TCV team,

    2015-01-01

    Measurements of various plasma parameters at the divertor targets of snowflake (SF) and conventional single-null configurations indicate an enhanced effect of the -->E*-->B drift in the scrape-off layer of plasmas in the SF configuration. Plasma boundary transport simulations using the EMC3-Ei

  20. Kebab: kinetochore and EB1 associated basic protein that dynamically changes its localisation during Drosophila mitosis.

    Science.gov (United States)

    Meireles, Ana M; Dzhindzhev, Nikola S; Ohkura, Hiroyuki

    2011-01-01

    Microtubule plus ends are dynamic ends that interact with other cellular structures. Microtubule plus end tracking proteins are considered to play important roles in the regulation of microtubule plus ends. Recent studies revealed that EB1 is the central regulator for microtubule plus end tracking proteins by recruiting them to microtubule plus ends through direct interaction. Here we report the identification of a novel Drosophila protein, which we call Kebab (kinetochore and EB1 associated basic protein), through in vitro expression screening for EB1-interacting proteins. Kebab fused to GFP shows a novel pattern of dynamic localisation in mitosis. It localises to kinetochores weakly in metaphase and accumulates progressively during anaphase. In telophase, it associates with microtubules in central-spindle and centrosomal regions. The localisation to kinetochores depends on microtubules. The protein has a domain most similar to the atypical CH domain of Ndc80, and a coiled-coil domain. The interaction with EB1 is mediated by two SxIP motifs but is not required for the localisation. Depletion of Kebab in cultured cells by RNA interference did not show obvious defects in mitotic progression or microtubule organisation. Generation of mutants lacking the kebab gene indicated that Kebab is dispensable for viability and fertility.

  1. Narvas näeb Eesti tantsuauhinna võitnud tantsulavastust / Rene Nõmmik ; intervjueerinud Tiia Linnart

    Index Scriptorium Estoniae

    Nõmmik, Rene, 1962-

    2015-01-01

    Narva kultuurimajas Rugodiv näeb Fine5 tantsuteatri lavastust "...and blue", mis võitis tänavu Eesti teatriauhinna. Etenduse koreograafideks ja lavastajateks on Tiina Ollesk ja Rene Nõmmik, keda on palutud lavastama ka Venemaale. Intervjuu Rene Nõmmikuga

  2. 47 CFR 73.4097 - EBS (now EAS) attention signals on automated programing systems.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false EBS (now EAS) attention signals on automated programing systems. 73.4097 Section 73.4097 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... (now EAS) attention signals on automated programing systems. See Public Notice dated March 1, 1979....

  3. Narvas näeb Eesti tantsuauhinna võitnud tantsulavastust / Rene Nõmmik ; intervjueerinud Tiia Linnart

    Index Scriptorium Estoniae

    Nõmmik, Rene, 1962-

    2015-01-01

    Narva kultuurimajas Rugodiv näeb Fine5 tantsuteatri lavastust "...and blue", mis võitis tänavu Eesti teatriauhinna. Etenduse koreograafideks ja lavastajateks on Tiina Ollesk ja Rene Nõmmik, keda on palutud lavastama ka Venemaale. Intervjuu Rene Nõmmikuga

  4. [Scientability - a concept for the handling of homeopathic remedies by EbM].

    Science.gov (United States)

    Weymayr, Christian

    2013-01-01

    Evidence-based medicine (EbM) has proved to be very useful in healthcare; thanks to its methodology the reliability of our knowledge of the benefits and harms of interventions can be assessed. This at least applies to interventions which are based on a plausible concept for their mechanism of action and which have already achieved positive effects in experiments and simple studies. However, for interventions whose concepts contradict scientific findings EbM has proved to be unsuitable; it has not been able to prevent that they are still regarded as effective amongst wide parts of the population and medical experts. Particularly homeopathy has managed to even present itself as scientifically justified by using EbM. With the aim of highlighting the speculative character of homeopathy and other procedures and of preventing EbM from getting damaged, the concept of scientability is introduced in this article. This concept only approves of clinical studies if the intervention that is to be tested does not contradict definite scientific findings. Copyright © 2013. Published by Elsevier GmbH.

  5. Kebab: kinetochore and EB1 associated basic protein that dynamically changes its localisation during Drosophila mitosis.

    Directory of Open Access Journals (Sweden)

    Ana M Meireles

    Full Text Available Microtubule plus ends are dynamic ends that interact with other cellular structures. Microtubule plus end tracking proteins are considered to play important roles in the regulation of microtubule plus ends. Recent studies revealed that EB1 is the central regulator for microtubule plus end tracking proteins by recruiting them to microtubule plus ends through direct interaction. Here we report the identification of a novel Drosophila protein, which we call Kebab (kinetochore and EB1 associated basic protein, through in vitro expression screening for EB1-interacting proteins. Kebab fused to GFP shows a novel pattern of dynamic localisation in mitosis. It localises to kinetochores weakly in metaphase and accumulates progressively during anaphase. In telophase, it associates with microtubules in central-spindle and centrosomal regions. The localisation to kinetochores depends on microtubules. The protein has a domain most similar to the atypical CH domain of Ndc80, and a coiled-coil domain. The interaction with EB1 is mediated by two SxIP motifs but is not required for the localisation. Depletion of Kebab in cultured cells by RNA interference did not show obvious defects in mitotic progression or microtubule organisation. Generation of mutants lacking the kebab gene indicated that Kebab is dispensable for viability and fertility.

  6. Complete genome sequence of Thioalkalivibrio sulfidophilus HL-EbGr7

    NARCIS (Netherlands)

    Muyzer, G.; Sorokin, D.Y.; Mavromatis, K.; Lapidus, A.; Clum, A.; Ivanova, N.; Pati, A.; d' Haeseleer, P.; Woyke, T.; Kyrpides, N.C.

    2011-01-01

    "Thioalkalivibrio sulfidophilus" HL-EbGr7 is an obligately chemolithoautotrophic, haloalkaliphilic sulfur-oxidizing bacterium (SOB) belonging to the Gammaproteobacteria. The strain was found to predominate a full-scale bioreactor, removing sulfide from biogas. Here we report the complete genome

  7. A Metallurgical Characterization and Assessment of SMA, GMA, EB, and LB Welds of HY-130 Steel.

    Science.gov (United States)

    1977-09-30

    and GMA welds consisted of a large percentage of acicular ferrite with smaller amounts of bainite and martensite; EB and LB welds comprised mostly...martensite and a small percentage of bainite . Strain hardening exponent values for SMA, GMA, and LB welds were appreciably higher than the values

  8. Robust EBS design and source-term analysis for the partially saturated Yucca Mountain Site

    Energy Technology Data Exchange (ETDEWEB)

    Apted, M. [Intera Information Technologies, Inc., Denver, CO (United States)

    1994-12-31

    The concept of robust repository design and assessment is examined. Successful demonstration of decoupling of near-field and far-field performance is a central principle in achieving robustness. An innovative design for the engineered barrier system (EBS) for the partially saturated conditions at Yucca Mountain is described based on this principle of robustness.

  9. 47 CFR 27.58 - Interference to BRS/EBS receivers.

    Science.gov (United States)

    2010-10-01

    ... downconverters if all of the following conditions are met: (1) The complaint is received by the WCS licensee...) The BRS/EBS customer or licensee has informed the WCS licensee of the interference within one year... increases at the WCS station. (b) Resolution of the complaint shall be at no cost to the complainant....

  10. The EB Factory Project. II. Validation with the Kepler Field in Preparation for K2 and TESS

    CERN Document Server

    Parvizi, Mahmoud; Stassun, Keivan G

    2014-01-01

    Large repositories of high precision light curve data, such as the Kepler data set, provide the opportunity to identify astrophysically important eclipsing binary (EB) systems in large quantities. However, the rate of classical "by eye" human analysis restricts complete and efficient mining of EBs from these data using classical techniques. To prepare for mining EBs from the upcoming K2 mission as well as other current missions, we developed an automated end-to-end computational pipeline - the Eclipsing Binary Factory (EBF) - that automatically identifies EBs and classifies them into morphological types. The EBF has been previously tested on ground-based light curves. To assess the performance of the EBF in the context of space-based data, we apply the EBF to the full set of light curves in the Kepler "Q3" Data Release. We compare the EBs identified from this automated approach against the human generated Kepler EB Catalog of ~2,600 EBs. When we require EB classification with at least 90% confidence, we find ...

  11. High Voltage Bi-directional Flyback Converter for Capacitive Actuator

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    This paper presents a high voltage DC-DC converter topology for bi-directional energy transfer between a low voltage DC source and a high voltage capacitive load. The topology is a bi-directional flyback converter with variable switching frequency control during the charge mode, and constant...... switching frequency control during the discharge mode. The converter is capable of charging the capacitive load from 24 V DC source to 2.5 kV, and discharges it to 0 V. The flyback converter has been analyzed in detail during both charge and discharge modes, by considering all the parasitic elements...... in the converter, including the most dominating parameters of the high voltage transformer viz., self-capacitance and leakage inductance. The specific capacitive load for this converter is a dielectric electro active polymer (DEAP) actuator, which can be used as an effective replacement for conventional actuators...

  12. Buck supplies output voltage ripple reduction using fuzzy control

    Directory of Open Access Journals (Sweden)

    Nicu BIZON

    2007-12-01

    Full Text Available Using the PWM control for switching power supplies the peaks EMI noise appear at the switching frequency and its harmonics. Using randomize or chaotic PWM control techniques in these systems the power spectrum is spread out in all frequencies band spectral emissions, but with a bigger ripple in the output voltage. The proposed nonlinear feedback control method, which induces chaos, is based by fuzzy rules that minimize the output voltage ripple. The feasibility and effectiveness of this relative simple method is shown by simulation. A comparison with the previous control method is included, too.

  13. Fast response double series resonant high-voltage DC-DC converter

    Science.gov (United States)

    Lee, S. S.; Iqbal, S.; Kamarol, M.

    2012-10-01

    In this paper, a novel double series resonant high-voltage dc-dc converter with dual-mode pulse frequency modulation (PFM) control scheme is proposed. The proposed topology consists of two series resonant tanks and hence two resonant currents flow in each switching period. Moreover, it consists of two high-voltage transformer with the leakage inductances are absorbed as resonant inductor in the series resonant tanks. The secondary output of both transformers are rectified and mixed before supplying to load. In the resonant mode operation, the series resonant tanks are energized alternately by controlling two Insulated Gate Bipolar Transistor (IGBT) switches with pulse frequency modulation (PFM). This topology operates in discontinuous conduction mode (DCM) with all IGBT switches operating in zero current switching (ZCS) condition and hence no switching loss occurs. To achieve fast rise in output voltage, a dual-mode PFM control during start-up of the converter is proposed. In this operation, the inverter is started at a high switching frequency and as the output voltage reaches 90% of the target value, the switching frequency is reduced to a value which corresponds to the target output voltage. This can effectively reduce the rise time of the output voltage and prevent overshoot. Experimental results collected from a 100-W laboratory prototype are presented to verify the effectiveness of the proposed system.

  14. A Survey on Voltage Boosting Techniques for Step-Up DC-DC Converters

    DEFF Research Database (Denmark)

    Forouzesh, Mojtaba; Siwakoti, Yam Prasad; Gorji, Saman Asghari;

    2016-01-01

    , researches on new voltage boosting techniques are inevitable for various power converter applications. This can be achieved either by additional magnetic or by electric field storage elements with switching elements (switch and/or diode) in different configurations. Such combination of primary voltage...... boosting techniques and topologies are large, which at times may be confusing and difficult to follow/adapt for different applications. Considering these aspects and in order to make a clear sketch of the general law and framework of various voltage boosting techniques, this paper comprehensively reviews...... different voltage boosting techniques and categorizes them according to their circuit performance....

  15. Switched on!

    CERN Multimedia

    2008-01-01

    Like a star arriving on stage, impatiently followed by each member of CERN personnel and by millions of eyes around the world, the first beam of protons has circulated in the LHC. After years in the making and months of increasing anticipation, today the work of hundreds of people has borne fruit. WELL DONE to all! Successfully steered around the 27 kilometres of the world’s most powerful particle accelerator at 10:28 this morning, this first beam of protons circulating in the ring marks a key moment in the transition from over two decades of preparation to a new era of scientific discovery. "It’s a fantastic moment," said the LHC project leader Lyn Evans, "we can now look forward to a new era of understanding about the origins and evolution of the universe". Starting up a major new particle accelerator takes much more than flipping a switch. Thousands of individual elements have to work in harmony, timings have to be synchronize...

  16. A New Phase-Shifted Cascade High Voltage Inverter

    Institute of Scientific and Technical Information of China (English)

    Lau Eng Tin

    2005-01-01

    This paper presents a unique novel design of the phase-shifted cascade high voltage inverter. Thehigh voltage inverter utilizes fewer power switches and supplies a balance load. The usage of phase shifttransformer and phase shifting SPWM ensures that input and output harmonic wave content is low and outputvoltage change (du/dt) has a low rate, meeting all the requirements of the power authorities. The most out-standing feature is the energy saving with very fast cost recovery.

  17. Matlab/Simulink Modeling of Four-leg Voltage Source Inverter With Fundamental Inverter output Voltages Vector Observation

    Directory of Open Access Journals (Sweden)

    Riyadh G. Omar

    2014-12-01

    Full Text Available Four-leg voltage source inverter is an evolution of the three-leg inverter, and was ought about by the need to handle the non-linear and unbalanced loads. In this work Matlab/ Simulink model is presented using space vector modulation technique. Simulation results for worst conditions of unbalanced linear and non-linear loads are obtained. Observation for the continuity of the fundamental inverter output voltages vector in stationary coordinate is detected for better performance. Matlab programs are executed in block functions to perform switching vector selection and space vector switching.

  18. The EB factory project. II. Validation with the Kepler field in preparation for K2 and TESS

    Energy Technology Data Exchange (ETDEWEB)

    Parvizi, Mahmoud; Paegert, Martin; Stassun, Keivan G., E-mail: mahmoud.parvizi@vanderbilt.edu [Department of Physics and Astronomy, Vanderbilt University, VU Station B 1807, Nashville, TN 37235 (United States)

    2014-12-01

    Large repositories of high precision light curve data, such as the Kepler data set, provide the opportunity to identify astrophysically important eclipsing binary (EB) systems in large quantities. However, the rate of classical “by eye” human analysis restricts complete and efficient mining of EBs from these data using classical techniques. To prepare for mining EBs from the upcoming K2 mission as well as other current missions, we developed an automated end-to-end computational pipeline—the Eclipsing Binary Factory (EBF)—that automatically identifies EBs and classifies them into morphological types. The EBF has been previously tested on ground-based light curves. To assess the performance of the EBF in the context of space-based data, we apply the EBF to the full set of light curves in the Kepler “Q3” Data Release. We compare the EBs identified from this automated approach against the human generated Kepler EB Catalog of ∼2600 EBs. When we require EB classification with ⩾90% confidence, we find that the EBF correctly identifies and classifies eclipsing contact (EC), eclipsing semi-detached (ESD), and eclipsing detached (ED) systems with a false positive rate of only 4%, 4%, and 8%, while complete to 64%, 46%, and 32%, respectively. When classification confidence is relaxed, the EBF identifies and classifies ECs, ESDs, and EDs with a slightly higher false positive rate of 6%, 16%, and 8%, while much more complete to 86%, 74%, and 62%, respectively. Through our processing of the entire Kepler “Q3” data set, we also identify 68 new candidate EBs that may have been missed by the human generated Kepler EB Catalog. We discuss the EBF's potential application to light curve classification for periodic variable stars more generally for current and upcoming surveys like K2 and the Transiting Exoplanet Survey Satellite.

  19. Electrocaloric devices based on thini-film heat switches

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, Richard I [Los Alamos National Laboratory; Malloy, Kevin J [UNM

    2009-01-01

    We describe a new approach to refrigeration and electrical generation that exploits the attractive properties of thin films of electrocaloric materials. Layers of electrocaloric material coupled with thin-film heat switches can work as either refrigerators or electrical generators, depending on the phasing of the applied voltages and heat switching. With heat switches based on thin layers of liquid crystals, the efficiency of these thin-film heat engines can be at least as high as that of current thermoelectric devices. Advanced heat switches would enable thin-film heat engines to outperform conventional vaporcompression devices.

  20. Carbon Nanotube Switches for Communication and Memory Applications

    Science.gov (United States)

    Kaul, Anupama B.; Epp, Larry; Wong, Eric W.; Kowalczyk, Robert

    2008-01-01

    Lateral CNT Switches: a) dc CNT switches were demonstrated to operate at low voltages, low powers and high speeds. b) RF simulations of switch in series configuration with metallized tube yielded good RF performance 1) Isolation simulated to be approx. 20 dB at 100 GHz. 2) Insertion loss simulated to be < 0.5 dB at 100 GHz. Vertical CNT Switches: a) Thermal CVD was used to mechanically constrain tubes in nanopockets; tubes not self-supporting. b) Demonstrated growth of vertically aligned arrays and single-few MWNTs using dc PECVD with Ni catalyst using optical lithography.

  1. Modelling and Analysis of High Pressure Peaking Switch

    Science.gov (United States)

    S, Bindu; Parekh, Mrunal; Mangalvedekar, H. A.; Sharma, Archana; Chakravarthy, D. P.

    2012-07-01

    This paper presents modelling and analysis of peaking switch used in Marx generator, such that the rise time of the pulse produced by the Marx generator is reduced substantially. Towards this FEMM (Finite Element Methods Magnetics) software is used for the field modelling of the switch and MATLAB for circuit modelling to observe the rise time. The switch has to produce pulse with sub-nanosecond rise time, hence the electrode distance has to be minimum. This switch can withstand high voltage only under high pressure. A mathematical model is simulated in MATLAB to see the performance under high pressure.

  2. Note: Complementary metal-oxide-semiconductor high voltage pulse generation circuits.

    Science.gov (United States)

    Sun, Jiwei; Wang, Pingshan

    2013-10-01

    We present two types of on-chip pulse generation circuits. The first is based on CMOS pulse-forming-lines (PFLs). It includes a four-stage charge pump, a four-stacked-MOSFET switch and a 5 mm long PFL. The circuit is implemented in a 0.13 μm CMOS process. Pulses of ~1.8 V amplitude with ~135 ps duration on a 50 Ω load are obtained. The obtained voltage is higher than 1.6 V, the rated operating voltage of the process. The second is a high-voltage Marx generator which also uses stacked MOSFETs as high voltage switches. The output voltage is 11.68 V, which is higher than the highest breakdown voltage (~10 V) of the CMOS process. These results significantly extend high-voltage pulse generation capabilities of CMOS technologies.

  3. Technological Aspects: High Voltage

    CERN Document Server

    Faircloth, D C

    2013-01-01

    This paper covers the theory and technological aspects of high-voltage design for ion sources. Electric field strengths are critical to understanding high-voltage breakdown. The equations governing electric fields and the techniques to solve them are discussed. The fundamental physics of high-voltage breakdown and electrical discharges are outlined. Different types of electrical discharges are catalogued and their behaviour in environments ranging from air to vacuum are detailed. The importance of surfaces is discussed. The principles of designing electrodes and insulators are introduced. The use of high-voltage platforms and their relation to system design are discussed. The use of commercially available high-voltage technology such as connectors, feedthroughs and cables are considered. Different power supply technologies and their procurement are briefly outlined. High-voltage safety, electric shocks and system design rules are covered.

  4. Cold-cathode, pulsed-power plasma discharge switch

    Science.gov (United States)

    Goebel, Dan M.

    1996-09-01

    CROSSATRONTMmodulator switches are cold-cathode, grid-controlled, plasma-discharge devices that are used for thyratron and hard-tube replacement in high-voltage, pulsed-power applications. CROSSATRON modulator switches have been used to produce square pulses of up to 100 kV and 1000 A, and CROSSATRON laser-discharge switches have switched peak discharge currents of up to 10 kA at 40 kV. The major advantage that CROSSATRON switches offer over other plasma switches is a rapid deionization time that permits high pulse-repetition frequencies (103 to 106 pulses per second depending on the application), and a long life associated with the cold-cathode plasma production mechanism. Compared to hard tubes, CROSSATRON switches have a relatively low forward voltage drop (500 V), the ability to close and open up to 1 kA of peak current, and lower grid-drive power requirements. In this article, we describe the physical mechanisms for how the switch works based on simple models and experimental data. The design of CROSSATRON switches is explained, and characteristic performance in closing and opening applications is described and explained.

  5. Stray voltage mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Jamali, B.; Piercy, R.; Dick, P. [Kinetrics Inc., Toronto, ON (Canada). Transmission and Distribution Technologies

    2008-04-09

    This report discussed issues related to farm stray voltage and evaluated mitigation strategies and costs for limiting voltage to farms. A 3-phase, 3-wire system with no neutral ground was used throughout North America before the 1930s. Transformers were connected phase to phase without any electrical connection between the primary and secondary sides of the transformers. Distribution voltage levels were then increased and multi-grounded neutral wires were added. The earth now forms a parallel return path for the neutral current that allows part of the neutral current to flow continuously through the earth. The arrangement is responsible for causing stray voltage. Stray voltage causes uneven milk production, increased incidences of mastitis, and can create a reluctance to drink water amongst cows when stray voltages are present. Off-farm sources of stray voltage include phase unbalances, undersized neutral wire, and high resistance splices on the neutral wire. Mitigation strategies for reducing stray voltage include phase balancing; conversion from single to 3-phase; increasing distribution voltage levels, and changing pole configurations. 22 refs., 5 tabs., 13 figs.

  6. High voltage engineering

    CERN Document Server

    Rizk, Farouk AM

    2014-01-01

    Inspired by a new revival of worldwide interest in extra-high-voltage (EHV) and ultra-high-voltage (UHV) transmission, High Voltage Engineering merges the latest research with the extensive experience of the best in the field to deliver a comprehensive treatment of electrical insulation systems for the next generation of utility engineers and electric power professionals. The book offers extensive coverage of the physical basis of high-voltage engineering, from insulation stress and strength to lightning attachment and protection and beyond. Presenting information critical to the design, selec

  7. High voltage test techniques

    CERN Document Server

    Kind, Dieter

    2001-01-01

    The second edition of High Voltage Test Techniques has been completely revised. The present revision takes into account the latest international developments in High Voltage and Measurement technology, making it an essential reference for engineers in the testing field.High Voltage Technology belongs to the traditional area of Electrical Engineering. However, this is not to say that the area has stood still. New insulating materials, computing methods and voltage levels repeatedly pose new problems or open up methods of solution; electromagnetic compatibility (EMC) or components and systems al

  8. Mitigation of Unbalanced Voltage Sags and Voltage Unbalance in CIGRE Low Voltage Distribution Network

    OpenAIRE

    Mustafa, Ghullam; Bak-Jensen, Birgitte; Mahat, Pukar; Cecati, Carlo

    2013-01-01

    Any problem with voltage in a power network is undesirable as it aggravates the quality of the power. Power electronic devices such as Voltage Source Converter (VSC) based Static Synchronous Compensator (STATCOM) etc. can be used to mitigate the voltage problems in the distribution system. The voltage problems dealt with in this paper are to show how to mitigate unbalanced voltage sags and voltage unbalance in the CIGRE Low Voltage (LV) test network and net-works like this. The voltage unbala...

  9. A Novel Crowbar Impulse Current Circuit for Testing the Switch-Type SPD

    Institute of Scientific and Technical Information of China (English)

    YAO Xueling; CHEN Jingliang; SUN Wei

    2008-01-01

    A crowbar impulse current circuit for testing the switch-type surge protective device (SPD) is presented. The crowbar circuit consists of a computer control circuit, a trigger voltage pulse generator, a main discharging switch, and a crowbar pseudospark switch. The active trigger technology was studied in the crowbar impulse current circuit. The circuit monitors the main discharging current and generates a trigger signal at a proper time for the crowbar pseudospark switch operation. The trigger characteristics of the main discharge switch and the crowbar pseudospark switch were investigated. By monitoring the preset applied capacitor voltage, the gap distance of the main discharging switch could be adjusted to ensure a discharging delay time less than 2 μs. Equipped with a surface flashover trigger device made of high relative perimittivity dielectric material BaTiO3 (εr = 3460), the discharge delay time of the crowbar pseudospark switch is less than 85 ns, and the minimum operating voltage is less than 1% of its self-breakdown voltage. With a storage capacitor of 9 μF , an inductor of 18 μH and a crowbar pseudospark switch, a load of 30 mΩ and an applied capacitor voltage of 40 kV, an impulse current wave form of maximum 25 kA was generated with a rise time and time to half peak value of 17.2/μs and 336 μs respectively.

  10. The Integration and Abstracyion of EBS Models in Yucca Mountain Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    S.D. Sevougian; V. Jain; A.V. Luik

    2006-01-11

    The safety strategy for geological disposal of radioactive waste at Yucca Mountain relies on a multi-barrier system to contain the waste and isolate it from the biosphere. The multi-barrier system consists of the natural barrier provided by the geological setting and the engineered barrier system (EBS). In the case of Yucca Mountain (YM) the geologic setting is the unsaturated-zone host rock, consisting of about 600 meters of layered ash-flow volcanic tuffs above the water table, and the saturated zone beneath the water table. Both the unsaturated and saturated rocks are part of a closed hydrologic basin in a desert surface environment. The waste is to be buried about halfway between the desert surface and the water table. The primary engineered barriers at YM consist of metal components that are highly durable in an oxidizing environment. The two primary components of the engineered barrier system are highly corrosion-resistant metal waste packages, made from a nickel-chromium-molybdenum alloy, Alloy 22, and titanium drip shields that protect the waste packages from corrosive dripping water and falling rocks. Design and performance assessment of the EBS requires models that describe how the EBS and near field behave under anticipated repository-relevant conditions. These models must describe coupled hydrologic, thermal, chemical, and mechanical (THCM) processes that drive radionuclide transport in a highly fractured host rock, consisting of a relatively permeable network of conductive fractures in a setting of highly impermeable tuff rock matrix. An integrated performance assessment of the EBS must include a quantification of the uncertainties that arise from (1) incomplete understanding of processes and (2) from lack of data representative of the large spatial scales and long time scales relevant to radioactive waste disposal (e.g., long-term metal corrosion rates and heterogeneities in rock properties over the large 5 km{sup 2} emplacement area of the repository

  11. Magnetically switched power supply system for lasers

    Science.gov (United States)

    Pacala, Thomas J. (Inventor)

    1987-01-01

    A laser power supply system is described in which separate pulses are utilized to avalanche ionize the gas within the laser and then produce a sustained discharge to cause the gas to emit light energy. A pulsed voltage source is used to charge a storage device such as a distributed capacitance. A transmission line or other suitable electrical conductor connects the storage device to the laser. A saturable inductor switch is coupled in the transmission line for containing the energy within the storage device until the voltage level across the storage device reaches a predetermined level, which level is less than that required to avalanche ionize the gas. An avalanche ionization pulse generating circuit is coupled to the laser for generating a high voltage pulse of sufficient amplitude to avalanche ionize the laser gas. Once the laser gas is avalanche ionized, the energy within the storage device is discharged through the saturable inductor switch into the laser to provide the sustained discharge. The avalanche ionization generating circuit may include a separate voltage source which is connected across the laser or may be in the form of a voltage multiplier circuit connected between the storage device and the laser.

  12. Development of Medium-Voltage and Large-Capacity Uninterruptible Power Supply System

    Science.gov (United States)

    Fujii, Kansuke; Kikuchi, Takayuki; Yoda, Kazuyuki

    A 2-MVA uninterruptible power supply (UPS) system has been developed for compensating for voltage dips in a medium voltage network. The UPS system realizes a high efficiency (99.7%) during single-pulse switching. In this paper, the UPS configurations, storage devices, and transfer switches are compared. Thereafter, the details of the UPS system, the results of the short-circuit test and the system efficiencies are described.

  13. Progress toward Treatment and Cure of Epidermolysis Bullosa: Summary of the DEBRA International Research Symposium EB2015.

    Science.gov (United States)

    Uitto, Jouni; Bruckner-Tuderman, Leena; Christiano, Angela M; McGrath, John A; Has, Cristina; South, Andrew P; Kopelan, Brett; Robinson, E Clare

    2016-02-01

    Epidermolysis bullosa (EB), a group of complex heritable blistering diseases, is the topic of triennial research meetings organized by DEBRA International, Vienna, Austria, the network of national EB patient advocacy organizations. The DEBRA 2015 Research Conference, held in May 2015, brought together investigators and clinicians from around the world working at the forefront of EB research. Discussing the state-of-the-art approaches from a wide range of disciplines, there was a palpable excitement at this conference brought about by the optimism about applying new sequencing techniques, genome editing, protein replacement, autologous and allogeneic stem cell therapy, innovations in cancer biology, revertant mosaicism, and induced pluripotent stem cell techniques, all of which are aimed at developing new therapies for EB. Many in the field who have participated in EB research for many years were especially enthusiastic and felt that, possibly for the first time, the field seems uniquely poised to bring these new tools to effectively tackle EB. Multiple complementary approaches are currently in motion toward improved quality of life and eventually a cure for patients suffering from EB, a currently intractable disease.

  14. High performance dc-dc conversion with voltage multipliers

    Science.gov (United States)

    Harrigill, W. T.; Myers, I. T.

    1974-01-01

    The voltage multipliers using capacitors and diodes first developed by Cockcroft and Walton in 1932 were reexamined in terms of state of the art fast switching transistors and diodes, and high energy density capacitors. Because of component improvements, the voltage multiplier, used without a transformer, now appears superior in weight to systems now in use for dc-dc conversion. An experimental 100-watt 1000-volt dc-dc converter operating at 100 kHz was built, with a component weight of about 1 kg/kW. Calculated and measured values of output voltage and efficiency agreed within experimental error.

  15. Reproducible and controllable induction voltage adder for scaled beam experiments

    Science.gov (United States)

    Sakai, Yasuo; Nakajima, Mitsuo; Horioka, Kazuhiko

    2016-08-01

    A reproducible and controllable induction adder was developed using solid-state switching devices and Finemet cores for scaled beam compression experiments. A gate controlled MOSFET circuit was developed for the controllable voltage driver. The MOSFET circuit drove the induction adder at low magnetization levels of the cores which enabled us to form reproducible modulation voltages with jitter less than 0.3 ns. Preliminary beam compression experiments indicated that the induction adder can improve the reproducibility of modulation voltages and advance the beam physics experiments.

  16. Important contribution of the novel locus comEB to extracellular DNA-dependent Staphylococcus lugdunensis biofilm formation.

    Science.gov (United States)

    Rajendran, Nithya Babu; Eikmeier, Julian; Becker, Karsten; Hussain, Muzaffar; Peters, Georg; Heilmann, Christine

    2015-12-01

    The coagulase-negative species Staphylococcus lugdunensis is an emerging cause of serious and potentially life-threatening infections, such as infective endocarditis. The pathogenesis of these infections is characterized by the ability of S. lugdunensis to form biofilms on either biotic or abiotic surfaces. To elucidate the genetic basis of biofilm formation in S. lugdunensis, we performed transposon (Tn917) mutagenesis. One mutant had a significantly reduced biofilm-forming capacity and carried a Tn917 insertion within the competence gene comEB. Site-directed mutagenesis and subsequent complementation with a functional copy of comEB verified the importance of comEB in biofilm formation. In several bacterial species, natural competence stimulates DNA release via lysis-dependent or -independent mechanisms. Extracellular DNA (eDNA) has been demonstrated to be an important structural component of many bacterial biofilms. Therefore, we quantified the eDNA in the biofilms and found diminished eDNA amounts in the comEB mutant biofilm. High-resolution images and three-dimensional data obtained via confocal laser scanning microscopy (CSLM) visualized the impact of the comEB mutation on biofilm integrity. The comEB mutant did not show reduced expression of autolysin genes, decreased autolytic activities, or increased cell viability, suggesting a cell lysis-independent mechanism of DNA release. Furthermore, reduced amounts of eDNA in the comEB mutant biofilms did not result from elevated levels or activity of the S. lugdunensis thermonuclease NucI. In conclusion, we defined here, for the first time, a role for the competence gene comEB in staphylococcal biofilm formation. Our findings indicate that comEB stimulates biofilm formation via a lysis-independent mechanism of DNA release.

  17. An Automatic Switched-Capacitor Cell Balancing Circuit for Series-Connected Battery Strings

    Directory of Open Access Journals (Sweden)

    Yuanmao Ye

    2016-02-01

    Full Text Available In this paper, a novel voltage equalizer is developed for series battery strings based on the two-phase switched capacitor technique. Different from the conventional voltage equalizers which are developed by switched-mode power converters, bulky magnetic components and complex monitoring and control system are avoided in the proposed system. Just a pair of complementary pulse signals with constant switching frequency and fixed duty ratio are required to control all of switches employed in the proposed voltage equalizer, and charge transfers from the higher voltage battery cells to lower voltage ones automatically. The circuit configuration and operation principle are provided in this paper. The model of the proposed voltage equalizer is also derived. Comparison with other works indicates that the proposed method is superior to the conventional switched-capacitor (SC voltage equalizer for the high stack of series battery strings. Experimental results demonstrate that the proposed voltage equalization system is capable of excellent voltage balancing performance with a simple control method.

  18. A high voltage ratio and low ripple interleaved DC-DC converter for fuel cell applications.

    Science.gov (United States)

    Chang, Long-Yi; Chao, Kuei-Hsiang; Chang, Tsang-Chih

    2012-01-01

    This paper proposes a high voltage ratio and low ripple interleaved boost DC-DC converter, which can be used to reduce the output voltage ripple. This converter transfers the low DC voltage of fuel cell to high DC voltage in DC link. The structure of the converter is parallel with two voltage-doubler boost converters by interleaving their output voltages to reduce the voltage ripple ratio. Besides, it can lower the current stress for the switches and inductors in the system. First, the PSIM software was used to establish a proton exchange membrane fuel cell and a converter circuit model. The simulated and measured results of the fuel cell output characteristic curve are made to verify the correctness of the established simulation model. In addition, some experimental results are made to validate the effectiveness in improving output voltage ripple of the proposed high voltage ratio interleaved boost DC-DC converters.

  19. Reduction of Switching Losses in Active Power Filters With a New Generalized Discontinuous-PWM Strategy

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Asiminoaei, Lucian; Malinowski, M.

    2008-01-01

    . It achieves a clamped voltage pattern, with variable lengths depending on the magnitude of the inverter current. This property reduces the current stress and minimizes the inverter switching losses. The proposed modulation strategy is described, analyzed, and validated on a three-phase voltage source inverter...... the switching losses in any operating point. This paper proposes a new DPWM strategy for shunt APFs. The proposed modulation strategy detects the current vector position relative to the inverter voltage reference and determines the optimum clamped duration for each phase, in terms of switching power losses...

  20. A compact, all solid-state LC high voltage generator.

    Science.gov (United States)

    Fan, Xuliang; Liu, Jinliang

    2013-06-01

    LC generator is widely applied in the field of high voltage generation technology. A compact and all solid-state LC high voltage generator based on saturable pulse transformer is proposed in this paper. First, working principle of the generator is presented. Theoretical analysis and circuit simulation are used to verify the design of the generator. Experimental studies of the proposed LC generator with two-stage main energy storage capacitors are carried out. And the results show that the proposed LC generator operates as expected. When the isolation inductance is 27 μH, the output voltage is 1.9 times larger than the charging voltage on single capacitor. The multiplication of voltages is achieved. On the condition that the primary energy storage capacitor is charged to 857 V, the output voltage of the generator can reach to 59.5 kV. The step-up ratio is nearly 69. When self breakdown gas gap switch is used as main switch, the rise time of the voltage pulse on load resistor is 8.7 ns. It means that the series-wound inductance in the discharging circuit is very small in this system. This generator can be employed in two different applications.

  1. EB病毒相关性肿瘤疾病%EB virus-associated tumors

    Institute of Scientific and Technical Information of China (English)

    肖智辉; 文飞球

    2010-01-01

    EB病毒(EBV)是一种能诱发肿瘤的疱疹病毒.近年来,有关EBV在人体内生存的机制、感染后的免疫调控、相关疾病的发病机制等方面均有了新的认识.现就近年来EBV相关性肿瘤的研究进展情况进行介绍.%Epstein-Barr virus is a herpes virus that is associated with many human neoplasms. In re-cent years, there are some developments for the research on the mechanism of survival of EBV in the human body,immune regulation after EBV infection and pathogenesis of EB virus-associated diseases. This article presents an overview and update of EB virus-associated tumors.

  2. Regulation of EB1/3 proteins by classical MAPs in neurons.

    Science.gov (United States)

    Sayas, C L; Avila, Jesús

    2014-01-01

    Microtubules (MTs) are key cytoskeletal elements in developing and mature neurons. MT reorganization underlies the morphological changes that occur during neuronal development. Furthermore, MTs contribute to the maintenance of neuronal architecture, enable intracellular transport and act as scaffolds for signaling molecules. Thus, a fine-tuned regulation of MT dynamics and stability is crucial for the correct differentiation and functioning of neurons. Different types of proteins contribute to the regulation of the MT state, such as plus-end tracking proteins (+TIPs), which interact with the plus-ends of growing microtubules, and classical microtubule-associated proteins (MAPs), which bind along the microtubule lattice. Recent evidence indicates that MAPs interplay with End Binding Proteins (EBs), the core +TIPs, in neuronal cells. This might contribute to the orchestrated regulation of MT dynamics in neurons. In this mini-review article, we address recent research on the neuronal crosstalk between EBs and classical MAPs and speculate on its possible functional relevance.

  3. Influence of surface modification on isothermal oxidation behavior of EB-PVD NiAl coating

    Institute of Scientific and Technical Information of China (English)

    LI He-fei; TAO Shu-feng; JIANG Kuo; A. HESNAWI; GONG Sheng-kai

    2006-01-01

    The isothermal oxidation behaviors of the as-deposited NiAl coating on the nickel-based superalloy by electron beam physical vapour deposition(EB-PVD) and the NiAl coating after surface modifications of grinding and polishing were investigated. The as-deposited coating shows the least mass gain, the initially formed θ-Al2O3 scale spalls after only 1 h, and the succeeding scale formed is coarse and discontinuous and thus can not be used as protective coatings. Among the two surface-modified coatings, the ground coating results in the highest oxide growth rate, which is consistent with the SEM results where the scale spalls heavily and many voids appear between the scale and the NiAl coating. The scale spallation and void formation mechanisms during isothermal oxidation test of EB-PVD NiAl coating were also discussed.

  4. e-Relationships for e-Readiness:culture and corruption in international e-B2B

    OpenAIRE

    Berthon, Pierre; Pitt, Leyland; Berthon, Jean-Paul; Campbell, Colin; Thwaites, Des

    2008-01-01

    The role of electronic networks in B2B relationships has been growing exponentially. From massive internet B2B exchanges to tiny RFID chips, B2B is increasingly becoming e-B2B. Whilst e-B2B has been explored intra-nationally, its international counterpart is less well documented; as has been the role that culture might play in the development of international e-B2B relationships. In this paper we address this important issue of international e-business relationships. Specifically we explore t...

  5. High-speed FSK Modulator Using Switched-capacitor Resonators

    CERN Document Server

    Salehi, Mohsen

    2015-01-01

    In this paper, an ultra-fast frequency shift-keying (FSK) modulation technique based on switched capacitor resonators is presented. It is demonstrated that switching a reactive component such as a capacitor, in a high-Q resonator with proper switching signal can preserve the stored energy and shift it to a different frequency. Switching boundaries are found by continuity of electric charge and magnetic flux. It is shown that if switching time is synchronous with zero crossing of the voltage signal across the switched capacitor, impulsive components can be avoided and continuity of electric charge is satisfied without energy dissipation. We use this property to realize a fast binary frequency-shift keying (FSK) modulator with only a single RF source. In this technique, the modulation rate is independent of the resonator bandwidth and can be as high as the lower carrier frequency. Experimental results are presented to validate the simulations.

  6. New method for capturing arc of moving on switching apparatus

    Institute of Scientific and Technical Information of China (English)

    LIU Jiao-min; WANG Jing-hong

    2007-01-01

    The switching arc that occurs in contact gap when contact of low voltage apparatus closes or breaks in electric circuit is harmful to the contacts, insulation, and reliability of electrical gear because of its very high temperature. As arcing time is very short in switching gear, it is very difficult to observe arc phenomena directly for researchers. Therefore, visualization of switching arc is important for understanding arc phenomena, to analyze the arc features, and to improve the design and reliability of switching gear. Based on analyzing the visualization methods proposed by researchers, a new switching arc capturing approach is introduced in this paper. Arc image acquisition, and image processing techniques were studied. A switching arc image acquisition and visual simulation software based on high speed CCD camera hard ware system was designed and implemented to yield enhanced arc image with good visual effect.

  7. Unity power factor switching regulator

    Science.gov (United States)

    Rippel, Wally E. (Inventor)

    1983-01-01

    A single or multiphase boost chopper regulator operating with unity power factor, for use such as to charge a battery is comprised of a power section for converting single or multiphase line energy into recharge energy including a rectifier (10), one inductor (L.sub.1) and one chopper (Q.sub.1) for each chopper phase for presenting a load (battery) with a current output, and duty cycle control means (16) for each chopper to control the average inductor current over each period of the chopper, and a sensing and control section including means (20) for sensing at least one load parameter, means (22) for producing a current command signal as a function of said parameter, means (26) for producing a feedback signal as a function of said current command signal and the average rectifier voltage output over each period of the chopper, means (28) for sensing current through said inductor, means (18) for comparing said feedback signal with said sensed current to produce, in response to a difference, a control signal applied to the duty cycle control means, whereby the average inductor current is proportionate to the average rectifier voltage output over each period of the chopper, and instantaneous line current is thereby maintained proportionate to the instantaneous line voltage, thus achieving a unity power factor. The boost chopper is comprised of a plurality of converters connected in parallel and operated in staggered phase. For optimal harmonic suppression, the duty cycles of the switching converters are evenly spaced, and by negative coupling between pairs 180.degree. out-of-phase, peak currents through the switches can be reduced while reducing the inductor size and mass.

  8. AUTOMATED EB BILLING SYSTEM USING GSM AND AD-HOC WIRELESS ROUTING

    Directory of Open Access Journals (Sweden)

    R.Saravanan

    2010-10-01

    Full Text Available With the passage of time, technology has merged itself with the daily life of humans. We have seen so much progress in the field of science and technology but we are not able to make full use of it. One such area for improvement is the Electricity board billing system. Our existing electricity board billing system in India is obsolete and time consuming. We are proposing a system through which electricity billing becomes fully automated and communication is made possiblevia wireless networks. The existing manual system in India has major drawbacks. This system is prone to errors and can also be easily manipulated. The prevailing manual system also requires lot of human workforce. The major disadvantage in this system is that the meter cannot be accessed by the meter reader if the customer is not present at home. In our system the central EB office has immediate access to all consumer homes in a locality with the help of an RF system. The EB meter present in each house is connected by wireless network with the EB office which periodically gets updates from the meter. The EB office using a backend database calculates the amount to be paid according to the number of units consumed and sends it back to the meter for display and also to the user’s mobile phone. The advantages of the proposed system make the existing system incompetent. It ispossible to connect to remote areas even when there is a power failure as it employs wireless technology. The new system is user friendly, easy to access and far more efficient than the existing system.

  9. Mainstreaming Ecosystem Services Based Climate Change Adaptation (EbA in Bangladesh: Status, Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Nazmul Huq

    2017-06-01

    Full Text Available The paper aims to analyze the extent of Ecosystem Service (ESS based Adaptation (EbA to climate change in the policy-making process of Bangladesh. The paper is based on a three stage hybrid policy-making cycle: (i agenda setting; (ii policy formulation; and (iii policy implementation stage, where the contributions of EbA can horizontally (on the ground or vertically (strategic stage be mainstreamed and integrated. A total of nine national and sectoral development and climate change policies, and 329 climate change adaptation projects are examined belonging to different policy-making stages. The major findings include that the role of ESS is marginally considered as an adaptation component in most of the reviewed policies, especially at the top strategic level (vertical mainstreaming. However, at the policy formulation and implementation stage (horizontal mainstreaming, they are largely ignored and priority is given to structural adaptation policies and projects, e.g., large scale concrete dams and embankments. For example, ESS’s roles to adapt sectors such as urban planning, biodiversity management and disaster risk reduction are left unchecked, and the implementation stage receives overwhelming priorities and investments to undertake hard adaptation measures such that only 38 projects are related to EbA. The paper argues that: (i dominant structural adaptation ideologies; (ii the expert and bureaucracy dependent policy making process; and (iii the lack of adaptive and integration capacities at institutional level are considerably offsetting the EbA mainstreaming process that need to be adequately addressed for climate change adaptation.

  10. Voltage verification unit

    Science.gov (United States)

    Martin, Edward J.

    2008-01-15

    A voltage verification unit and method for determining the absence of potentially dangerous potentials within a power supply enclosure without Mode 2 work is disclosed. With this device and method, a qualified worker, following a relatively simple protocol that involves a function test (hot, cold, hot) of the voltage verification unit before Lock Out/Tag Out and, and once the Lock Out/Tag Out is completed, testing or "trying" by simply reading a display on the voltage verification unit can be accomplished without exposure of the operator to the interior of the voltage supply enclosure. According to a preferred embodiment, the voltage verification unit includes test leads to allow diagnostics with other meters, without the necessity of accessing potentially dangerous bus bars or the like.

  11. Voltage Regulator for a dc-to-dc Converter

    Science.gov (United States)

    Mclyman, C. W.

    1983-01-01

    New voltage regulator isolates signals from power-switching converter without use of complex circuitry or optical couplers. Only addition is extra secondary winding on existing interstage transformer. Error signals shortcircuit new winding and inhibit converter action. Resistor in series with primary winding limits short-circuit current to prevent damage to circuit components. Extra transformer winding eliminates need for isolation components.

  12. WAVELET BASED CLASSIFICATION OF VOLTAGE SAG, SWELL & TRANSIENTS

    Directory of Open Access Journals (Sweden)

    Vijay Gajanan Neve

    2013-05-01

    Full Text Available When the time localization of the spectral components is needed, the WAVELE TRANSFORM (WT can be used to obtain the optimal time frequency representation of the signal. This paper deals with the use of a wavelet transform to detect and analyze voltage sags, voltage swell and transients. It introduces voltage disturbance detection approach based on wavelet transform, identifies voltage disturbances, and discriminates the type of event which has resulted in the voltage disturbance, e.g. either a fault or a capacitor-switching incident.Feasibility of the proposed disturbance detection approach is demonstrated based on digital time-domain simulation of a distribution power system using the PSCAD software package, and is implemented using MATLAB. The developed algorithm has been applied to the 14-buses IEEE system to illustrate its application. Results are analyzed.

  13. 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.

  14. DOE-Managed HLW and SNF Research: FY15 EBS and Thermal Analysis Work Package Status.

    Energy Technology Data Exchange (ETDEWEB)

    Matteo, Edward N. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Hadgu, Teklu [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    This report examines the technical elements necessary to evaluate EBS concepts and perform thermal analysis of DOE-Managed SNF and HLW in the disposal settings of primary interest – argillite, crystalline, salt, and deep borehole. As the disposal design concept is composed of waste inventory, geologic setting, and engineered concept of operation, the engineered barrier system (EBS) falls into the last component of engineered concept of operation. The waste inventory for DOE-Managed HLW and SNF is closely examined, with specific attention to the number of waste packages, the size of waste packages, and the thermal output per package. As expected, the DOE-Managed HLW and SNF inventory has a much smaller volume, and hence smaller number of canisters, as well a lower thermal output, relative to a waste inventory that would include commercial spent nuclear fuel (CSNF). A survey of available data and methods from previous studies of thermal analysis indicates that, in some cases, thermo-hydrologic modeling will be necessary to appropriately address the problem. This report also outlines scope for FY16 work -- a key challenge identified is developing a methodology to effectively and efficiently evaluate EBS performance in each disposal setting on the basis of thermal analyses results.

  15. Novel, Four-Switch, Z-Source Three-Phase Inverter

    DEFF Research Database (Denmark)

    Antal, Robert; Muntean, Nicolae; Boldea, Ion

    2010-01-01

    ) value as in six switch standard three-phase inverter. The article presents the derivation of the equations describing the operation of the converter based on space vector analysis, validation through digital simulations in PSIM and preliminary experimental results on a laboratory setup with a dsPIC30F......, besides the self-boost property, has low switch count and it can operate as a buck-boost inverter. In contrast to standard four-switch three-phase inverter which operates at half dc input voltage the proposed four-switch z-source inverter, by self boosting, brings the output voltage at same (or higher...

  16. Voltage source inverters for high power, variable-voltage DC power sources

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z. [Department of Engineering and Technology, De Montfort University, Queens Building, The Gateway, Leicester, LE1 9BH, (United Kingdom); Spooner, E. [School of Engineering, University of Durham, Science Laboratories, South Rd, Durham, DRI 3LE, (United Kingdom)

    2001-09-01

    The paper discusses the applications of voltage source inverter (VSI) based power electronic systems for interfacing variable-voltage DC sources to the grid. A variable-speed wind power conversion system is used for illustration, where the VSI-based interface needs to convert a variable DC voltage to a nearly constant AC voltage with high-quality power. The power control principles of VSI are described. Various system configurations and switching strategies are examined by analysis, simulation and experimental methods. It is shown that better utilisation of semiconductors and more flexible control may be achieved by using a separately controlled DC link, rather than a directly connected VSI that has to operate at a lower modulation ratio at higher power. In some cases, multipulse inverter structures may be preferred, despite higher component count, because of reduced switching losses, fault tolerance and the absence of filters. The solutions developed in the study could be applied at a different scale to other renewable energy sources, such as wave or solar photovoltaic devices. (Author)

  17. Latching micro optical switch

    Science.gov (United States)

    Garcia, Ernest J; Polosky, Marc A

    2013-05-21

    An optical switch reliably maintains its on or off state even when subjected to environments where the switch is bumped or otherwise moved. In addition, the optical switch maintains its on or off state indefinitely without requiring external power. External power is used only to transition the switch from one state to the other. The optical switch is configured with a fixed optical fiber and a movable optical fiber. The movable optical fiber is guided by various actuators in conjunction with a latching mechanism that configure the switch in one position that corresponds to the on state and in another position that corresponds to the off state.

  18. The effect of oxygen vacancy on switching mechanism of ZnO resistive switching memory

    Science.gov (United States)

    Hu, Cong; Wang, Qi; Bai, Shuai; Xu, Min; He, Deyan; Lyu, Deyuan; Qi, Jing

    2017-02-01

    Oxygen vacancy (Vo) is believed to control the switching mechanism of metal oxide resistive switching memory. However, an accurate and quantitative theory to prove this point of view remains absent. In this letter, we propose a model combining the Poole-Frenkel effect, space charge limited current, and the modification of Vo density to simulate the current-voltage curves. The calculated results show reasonable agreements with the experimental data, which indicates that resistive switching between high resistance state and low resistance state in the devices of Al/ZnO/p+-Si is led by the density change of Vo. Furthermore, the essence of this leading effect of Vo density is explained by electrons capture and emission via oxygen vacancies. This research demonstrates the significance of Vo in theory and gives an insight into the switching mechanism.

  19. Study on Establishment of the Main Flowchart of CPFR Based on ebXML%基于ebXML的CPFR主要流程构建与实施研究

    Institute of Scientific and Technical Information of China (English)

    刘斌; 王喜富

    2009-01-01

    通过分析CPFR实施过程中对信息技术的要求,结合ebXML自身特点,指出在CPFR实施中建立基于ebxML的信息交换平台的必要性,并根据CPFR实施的步骤,构建了基于ebXML的CPFR主要步骤的流程模型.

  20. Voltage scheduling for low power/energy

    Science.gov (United States)

    Manzak, Ali

    2001-07-01

    Power considerations have become an increasingly dominant factor in the design of both portable and desk-top systems. An effective way to reduce power consumption is to lower the supply voltage since voltage is quadratically related to power. This dissertation considers the problem of lowering the supply voltage at (i) the system level and at (ii) the behavioral level. At the system level, the voltage of the variable voltage processor is dynamically changed with the work load. Processors with limited sized buffers as well as those with very large buffers are considered. Given the task arrival times, deadline times, execution times, periods and switching activities, task scheduling algorithms that minimize energy or peak power are developed for the processors equipped with very large buffers. A relation between the operating voltages of the tasks for minimum energy/power is determined using the Lagrange multiplier method, and an iterative algorithm that utilizes this relation is developed. Experimental results show that the voltage assignment obtained by the proposed algorithm is very close (0.1% error) to that of the optimal energy assignment and the optimal peak power (1% error) assignment. Next, on-line and off-fine minimum energy task scheduling algorithms are developed for processors with limited sized buffers. These algorithms have polynomial time complexity and present optimal (off-line) and close-to-optimal (on-line) solutions. A procedure to calculate the minimum buffer size given information about the size of the task (maximum, minimum), execution time (best case, worst case) and deadlines is also presented. At the behavioral level, resources operating at multiple voltages are used to minimize power while maintaining the throughput. Such a scheme has the advantage of allowing modules on the critical paths to be assigned to the highest voltage levels (thus meeting the required timing constraints) while allowing modules on non-critical paths to be assigned

  1. High voltage dc-dc converter with dynamic voltage regulation and decoupling during load-generated arcs

    Science.gov (United States)

    Shimer, Daniel W.; Lange, Arnold C.

    1995-01-01

    A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

  2. FPGA Techniques Based New Hybrid Modulation Strategies for Voltage Source Inverters

    OpenAIRE

    Sudha, L. U.; J. Baskaran; Elankurisil, S. A.

    2015-01-01

    This paper corroborates three different hybrid modulation strategies suitable for single-phase voltage source inverter. The proposed method is formulated using fundamental switching and carrier based pulse width modulation methods. The main tale of this proposed method is to optimize a specific performance criterion, such as minimization of the total harmonic distortion (THD), lower order harmonics, switching losses, and heat losses. The proposed method is articulated using fundamental switch...

  3. Uninterruptible system for switching between two different power sources; Idengenkan muteiden kirikae system

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-12-17

    The above system with a patent pending is described. When a regular power source is to be temporarily stopped, a switchover is made to a mobile generator. After such a switchover, the temporary switch is heavier because of the transformer for driving instruments, and this creates a problem in workability. In this invention, a voltage detector built of a partial voltage circuit of small and light capacitors is provided at each end of the temporary switch. The detectors, together with a contact arrangement which generates a switch closing signal, constitutes a temporary switch for the synchronous closing of different power sources. A temporary switch control device is connected to the switch by coupling cables and, across the cables, a means that performs synchronism detection in response to signals from the voltage detector and a voltage/frequency adjustment circuit are installed. Their signals are transmitted to a mobile generator equipped with a parallel operator. The mobile generator is equipped with a circuit to compensate for cross currents to operate when in parallel operation. In this invention, thanks to the use of capacitor partial voltage-aided voltage detector in place of a transformer for instruments, the temporary switch is reduced in weight. The cross current compensation circuit inhibits the reactive current in case of switchback. (NEDO)

  4. Neutron and gamma irradiation effects on power semiconductor switches

    Science.gov (United States)

    Schwarze, G. E.; Frasca, A. J.

    1990-01-01

    The performance characteristics of high power semiconductor switches subjected to high levels of neutron fluence and gamma dose must be known by the designer of the power conditioning, control and transmission subsystem of space nuclear power systems. Location and the allowable shielding mass budget will determine the level of radiation tolerance required by the switches to meet performance and reliability requirements. Neutron and gamma ray interactions with semiconductor materials and how these interactions affect the electrical and switching characteristics of solid state power switches is discussed. The experimental measurement system and radiation facilities are described. Experimental data showing the effects of neutron and gamma irradiation on the performance characteristics are given for power-type NPN Bipolar Junction Transistors (BJTs), and Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs). BJTs show a rapid decrease in gain, blocking voltage, and storage time for neutron irradiation, and MOSFETs show a rapid decrease in the gate threshold voltage for gamma irradiation.

  5. Shuttle-promoted nano-mechanical current switch

    Energy Technology Data Exchange (ETDEWEB)

    Song, Taegeun, E-mail: tsong@ictp.it; Kiselev, Mikhail N. [Condensed Matter and Statistical Physics Section, The Abdus Salam International Center for Theoretical Physics, I-34151 Trieste (Italy); Gorelik, Leonid Y. [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Shekhter, Robert I. [Department of Physics, University of Gothenburg, SE-412 96 Göteborg (Sweden); Kikoin, Konstantin [School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel)

    2015-09-21

    We investigate electron shuttling in three-terminal nanoelectromechanical device built on a movable metallic rod oscillating between two drains. The device shows a double-well shaped electromechanical potential tunable by a source-drain bias voltage. Four stationary regimes controllable by the bias are found for this device: (i) single stable fixed point, (ii) two stable fixed points, (iii) two limit cycles, and (iv) single limit cycle. In the presence of perpendicular magnetic field, the Lorentz force makes possible switching from one electromechanical state to another. The mechanism of tunable transitions between various stable regimes based on the interplay between voltage controlled electromechanical instability and magnetically controlled switching is suggested. The switching phenomenon is implemented for achieving both a reliable active current switch and sensoring of small variations of magnetic field.

  6. Giant thermal spin-torque-assisted magnetic tunnel junction switching.

    Science.gov (United States)

    Pushp, Aakash; Phung, Timothy; Rettner, Charles; Hughes, Brian P; Yang, See-Hun; Parkin, Stuart S P

    2015-05-26

    Spin-polarized charge currents induce magnetic tunnel junction (MTJ) switching by virtue of spin-transfer torque (STT). Recently, by taking advantage of the spin-dependent thermoelectric properties of magnetic materials, novel means of generating spin currents from temperature gradients, and their associated thermal-spin torques (TSTs), have been proposed, but so far these TSTs have not been large enough to influence MTJ switching. Here we demonstrate significant TSTs in MTJs by generating large temperature gradients across ultrathin MgO tunnel barriers that considerably affect the switching fields of the MTJ. We attribute the origin of the TST to an asymmetry of the tunneling conductance across the zero-bias voltage of the MTJ. Remarkably, we estimate through magneto-Seebeck voltage measurements that the charge currents that would be generated due to the temperature gradient would give rise to STT that is a thousand times too small to account for the changes in switching fields that we observe.

  7. Thermodynamics of Phase Transitions and Bipolar Filamentary Switching in Resistive Random-Access Memory

    Science.gov (United States)

    Karpov, V. G.; Niraula, D.; Karpov, I. V.; Kotlyar, R.

    2017-08-01

    We present a phenomenological theory of bipolar filamentary resistive random-access memory describing the commonly observed features of their current-voltage characteristics. Our approach follows the approach of a thermodynamic theory developed earlier for chalcogenide memory and threshold switches and largely independent of their microscopic details. It explains, without adjustable parameters, such features as the domains of filament formation and switching, voltage-independent current in set and current-independent voltage in reset regimes, the relation between the set and reset voltages, filament resistance independent of its length, etc. Furthermore, it expresses the observed features through the material and circuitry parameters, thus paving the way to device improvements.

  8. Micromagnetic simulation of electric-field-assisted magnetization switching in perpendicular magnetic tunnel junction

    Directory of Open Access Journals (Sweden)

    Chikako Yoshida

    2017-05-01

    Full Text Available The feasibility of a voltage assisted unipolar switching in perpendicular magnetic tunnel junction (MTJ has been studied using a micromagnetic simulation. Assuming a linear modulation of anisotropy field with voltage, both parallel (P to anti-parallel (AP and AP to P switchings were observed by application of unipolar voltage pulse without external magnetic field assistance. In latter case, the final P state can only be achieved with an ultrashort voltage pulse which vanishes before spin transfer torque (STT becomes dominant to restore the initial AP state. In addition, it was found that the larger change in anisotropy field is required for the MTJ with smaller diameter.

  9. Micromagnetic simulation of electric-field-assisted magnetization switching in perpendicular magnetic tunnel junction

    Science.gov (United States)

    Yoshida, Chikako; Noshiro, Hideyuki; Yamazaki, Yuichi; Sugii, Toshihiro; Tanaka, Tomohiro; Furuya, Atsushi; Uehara, Yuji

    2017-05-01

    The feasibility of a voltage assisted unipolar switching in perpendicular magnetic tunnel junction (MTJ) has been studied using a micromagnetic simulation. Assuming a linear modulation of anisotropy field with voltage, both parallel (P) to anti-parallel (AP) and AP to P switchings were observed by application of unipolar voltage pulse without external magnetic field assistance. In latter case, the final P state can only be achieved with an ultrashort voltage pulse which vanishes before spin transfer torque (STT) becomes dominant to restore the initial AP state. In addition, it was found that the larger change in anisotropy field is required for the MTJ with smaller diameter.

  10. SVPWM Technique with Varying DC-Link Voltage for Common Mode Voltage Reduction in a Matrix Converter and Analytical Estimation of its Output Voltage Distortion

    Science.gov (United States)

    Padhee, Varsha

    Common Mode Voltage (CMV) in any power converter has been the major contributor to premature motor failures, bearing deterioration, shaft voltage build up and electromagnetic interference. Intelligent control methods like Space Vector Pulse Width Modulation (SVPWM) techniques provide immense potential and flexibility to reduce CMV, thereby targeting all the afore mentioned problems. Other solutions like passive filters, shielded cables and EMI filters add to the volume and cost metrics of the entire system. Smart SVPWM techniques therefore, come with a very important advantage of being an economical solution. This thesis discusses a modified space vector technique applied to an Indirect Matrix Converter (IMC) which results in the reduction of common mode voltages and other advanced features. The conventional indirect space vector pulse-width modulation (SVPWM) method of controlling matrix converters involves the usage of two adjacent active vectors and one zero vector for both rectifying and inverting stages of the converter. By suitable selection of space vectors, the rectifying stage of the matrix converter can generate different levels of virtual DC-link voltage. This capability can be exploited for operation of the converter in different ranges of modulation indices for varying machine speeds. This results in lower common mode voltage and improves the harmonic spectrum of the output voltage, without increasing the number of switching transitions as compared to conventional modulation. To summarize it can be said that the responsibility of formulating output voltages with a particular magnitude and frequency has been transferred solely to the rectifying stage of the IMC. Estimation of degree of distortion in the three phase output voltage is another facet discussed in this thesis. An understanding of the SVPWM technique and the switching sequence of the space vectors in detail gives the potential to estimate the RMS value of the switched output voltage of any

  11. An Integrated Inductor For Parallel Interleaved Three-Phase Voltage Source Converters

    DEFF Research Database (Denmark)

    Gohil, Ghanshyamsinh Vijaysinh; Bede, Lorand; Teodorescu, Remus;

    2016-01-01

    Three phase Voltage Source Converters (VSCs) are often connected in parallel to realize high current output converter system. The harmonic quality of the resultant switched output voltage can be improved by interleaving the carrier signals of these parallel connected VSCs. As a result, the line...

  12. [Design of a high-voltage insulation testing system of X-ray high frequency generators].

    Science.gov (United States)

    Huang, Yong; Mo, Guo-Ming; Wang, Yan; Wang, Hong-Zhi; Yu, Jie-Ying; Dai, Shu-Guang

    2007-09-01

    In this paper, we analyze the transformer of X-ray high-voltage high-frequency generators and, have designed and implemented a high-voltage insulation testing system for its oil tank using full-bridge series resonant soft switching PFM DC-DC converter.

  13. Microstructural, mechanical and oxidation features of NiCoCrAlY coating produced by plasma activated EB-PVD

    Energy Technology Data Exchange (ETDEWEB)

    He, Jian; Guo, Hongbo, E-mail: guo.hongbo@buaa.edu.cn; Peng, Hui; Gong, Shengkai

    2013-06-01

    NiCoCrAlY coatings produced by electron beam-physical vapor deposition (EB-PVD) have been extensively used as the oxidation resistance coatings or suitable bond coats in thermal barrier coating (TBC) system. However, the inherent imperfections caused by EB-PVD process degrade the oxidation resistance of the coatings. In the present work, NiCoCrAlY coatings were creatively produced by plasma activated electron beam-physical vapor deposition (PA EB-PVD). The novel coatings showed a terraced substructure on the surface of each grain due to the increased energy of metal ions and enhanced mobility of adatoms. Also a strong (1 1 1) crystallographic texture of γ/γ′ grains was observed. The toughness of the coatings got remarkably improved compared with the coatings deposited by conventional EB-PVD and the oxidation behavior at 1373 K showed that the novel coatings had excellent oxidation resistance. The possible mechanism was finally discussed.

  14. Electrical switching in bulk samples of 0. 15As-0. 12Ge-0. 73Te glass

    Energy Technology Data Exchange (ETDEWEB)

    Eckels, D.E.

    1976-06-01

    Switching in bulk samples of 0.15As--0.12Ge--0.73Te glass is found to be caused predominantly by the thermal switching mechanism for near threshold applied voltages. Switching also occurred by the thermal mechanism even for applied voltages an order of magnitude above the threshold voltage of the sample. In order to investigate a switching event in this glass sample, a constant voltage pulse was applied to the sample and the delay time and the electrical energy input to the sample during the delay time measured. A log--log plot of the energy input to the sample during a delay time of 1.00 s as a function of the electrode spacing on the sample's surface was found to have a slope of approximately 1.6. For the theoretical study of the thermal switching mechanism, a one-dimensional calculation of the heat balance equation with radial heat flow was made and the results of the calculation followed the same trends as the experimental data. The large scatter in parts of the data and the increase in the average resistance of the sample for a switching event with near threshold applied voltages could not be explained by the thermal switching mechanism. These effects could be a manifestation of the structural changes which probably occur in the sample as a result of the high temperatures present at the moment of switching. 33 fig.

  15. The Integration of EDI and JDF Based on ebXML%基于ebXML规范实现EDI与JDF的集成

    Institute of Scientific and Technical Information of China (English)

    徐骁俊; 丁岳伟

    2006-01-01

    传统的B2B信息化应用中,EDI(Electronic Data Interface)最大缺点在于没有一个统一规范的标准.我们提供一种开放的技术框架将XML作为数据载体,利用现有的网络资源基础上进行电子数据交换.本文在此基础上,提出了一种在印刷行业SCM系统中,将基于全球统一ebXML规范的XML/EDI与JDF(Job Definition Format作业定义格式)的集成解决方法.

  16. Nanoeletromechanical switch and logic circuits formed therefrom

    Science.gov (United States)

    Nordquist, Christopher D [Albuquerque, NM; Czaplewski, David A [Albuquerque, NM

    2010-05-18

    A nanoelectromechanical (NEM) switch is formed on a substrate with a source electrode containing a suspended electrically-conductive beam which is anchored to the substrate at each end. This beam, which can be formed of ruthenium, bows laterally in response to a voltage applied between a pair of gate electrodes and the source electrode to form an electrical connection between the source electrode and a drain electrode located near a midpoint of the beam. Another pair of gate electrodes and another drain electrode can be located on an opposite side of the beam to allow for switching in an opposite direction. The NEM switch can be used to form digital logic circuits including NAND gates, NOR gates, programmable logic gates, and SRAM and DRAM memory cells which can be used in place of conventional CMOS circuits, or in combination therewith.

  17. Chalcogenide Nanoionic-based Radio Frequency Switch

    Science.gov (United States)

    Nessel, James (Inventor); Lee, Richard (Inventor)

    2013-01-01

    A nonvolatile nanoionic switch is disclosed. A thin layer of chalcogenide glass engages a substrate and a metal selected from the group of silver and copper photo-dissolved in the chalcogenide glass. A first oxidizable electrode and a second inert electrode engage the chalcogenide glass and are spaced apart from each other forming a gap therebetween. A direct current voltage source is applied with positive polarity applied to the oxidizable electrode and negative polarity applied to the inert electrode which electrodeposits silver or copper across the gap closing the switch. Reversing the polarity of the switch dissolves the electrodeposited metal and returns it to the oxidizable electrode. A capacitor arrangement may be formed with the same structure and process.

  18. Optical packet switched networks

    DEFF Research Database (Denmark)

    Hansen, Peter Bukhave

    1999-01-01

    Optical packet switched networks are investigated with emphasis on the performance of the packet switch blocks. Initially, the network context of the optical packet switched network is described showing that a packet network will provide transparency, flexibility and bridge the granularity gap...... between the electrical switched layer and the WDM transport layer. Analytical models are implemented to determine the signal quality ghrough the switch blocks in terms of power penalty and to assess the traffic performance of different switch block architectures. Further, a computer simulation model...... is used to investigate the influence on the traffic performance of asynchronous operation of the switch blocks. The signal quality investigation illustrates some of the component requirements in respect to gain saturation in SOA gates and crosstalk in order to obtain high cascadability of the switch...

  19. BPAG1a and b associate with EB1 and EB3 and modulate vesicular transport, Golgi apparatus structure, and cell migration in C2.7 myoblasts.

    Directory of Open Access Journals (Sweden)

    Kseniia Poliakova

    Full Text Available BPAG1a and BPAG1b (BPAG1a/b constitute two major isoforms encoded by the dystonin (Dst gene and show homology with MACF1a and MACF1b. These proteins are members of the plakin family, giant multi-modular proteins able to connect the intermediate filament, microtubule and microfilament cytoskeletal networks with each other and to distinct cell membrane sites. They also serve as scaffolds for signaling proteins that modulate cytoskeletal dynamics. To gain better insights into the functions of BPAG1a/b, we further characterized their C-terminal region important for their interaction with microtubules and assessed the role of these isoforms in the cytoskeletal organization of C2.7 myoblast cells. Our results show that alternative splicing does not only occur at the 5' end of Dst and Macf1 pre-mRNAs, as previously reported, but also at their 3' end, resulting in expression of additional four mRNA variants of BPAG1 and MACF1. These isoform-specific C-tails were able to bundle microtubules and bound to both EB1 and EB3, two microtubule plus end proteins. In the C2.7 cell line, knockdown of BPAG1a/b had no major effect on the organization of the microtubule and microfilament networks, but negatively affected endocytosis and maintenance of the Golgi apparatus structure, which became dispersed. Finally, knockdown of BPAG1a/b caused a specific decrease in the directness of cell migration, but did not impair initial cell adhesion. These data provide novel insights into the complexity of alternative splicing of Dst pre-mRNAs and into the role of BPAG1a/b in vesicular transport, Golgi apparatus structure as well as in migration in C2.7 myoblasts.

  20. Plasma opening switch studies of an applied Bz ion diode

    Science.gov (United States)

    Struckman, C. K.; Kusse, B. R.; Meyerhofer, D. D.; Rondeau, G.

    1989-05-01

    The light ion accelerator (1.5 MV, 4 ohms) at Cornell University is being used to study the characteristics of an applied Bz, or 'barrel', diode. The results of a series of experiments utilizing a plasma opening switch are reported. With a magnetically insulated ion diode load, the peak diode voltage increase from 1.5 to 1.8 MV and the ion power increased from 50 to 80 GW when a plasma opening switch was used.

  1. Electrostatic Switching in Vertically Oriented Nanotubes for Nonvolatile Memory Applications

    Science.gov (United States)

    Kaul, Anupama B.; Khan, Paul; Jennings, Andrew T.; Greer, Julia R.; Megerian, Krikor G.; Allmen, Paul von

    2009-01-01

    We have demonstrated electrostatic switching in vertically oriented nanotubes or nanofibers, where a nanoprobe was used as the actuating electrode inside an SEM. When the nanoprobe was manipulated to be in close proximity to a single tube, switching voltages between 10 V - 40 V were observed, depending on the geometrical parameters. The turn-on transitions appeared to be much sharper than the turn-off transitions which were limited by the tube-to-probe contact resistances. In many cases, stiction forces at these dimensions were dominant, since the tube appeared stuck to the probe even after the voltage returned to 0 V, suggesting that such structures are promising for nonvolatile memory applications. The stiction effects, to some extent, can be adjusted by engineering the switch geometry appropriately. Nanoscale mechanical measurements were also conducted on the tubes using a custom-built anoindentor inside an SEM, from which preliminary material parameters, such as the elastic modulus, were extracted. The mechanical measurements also revealed that the tubes appear to be well adhered to the substrate. The material parameters gathered from the mechanical measurements were then used in developing an electrostatic model of the switch using a commercially available finite-element simulator. The calculated pull-in voltages appeared to be in agreement to the experimentally obtained switching voltages to first order.

  2. Electromechanical resistive switching via back-to-back Schottky junctions

    Science.gov (United States)

    Li, Lijie

    2015-09-01

    The physics of the electromechanical resistive switching is uncovered using the theory of back-to-back Schottky junctions combined with the quantum domain space charge transport. A theoretical model of the basic element of resistive switching devices realized by the metal-ZnO nanowires-metal structure has been created and analyzed. Simulation results show that the reverse biased Schottky junction and the air gap impedance dominate the current-voltage relation at higher external voltages; thereby electromechanically varying the air gap thickness causes the device exhibit resistive tuning characteristics. As the device dimension is in nanometre scale, investigation of the model based on quantum mechanics has also been conducted.

  3. Experimental study on the characteristics of semiconductor opening switch

    CERN Document Server

    Su Jian Cang; Ding Yong Zhong; Song Zhi Min; Ding Zhen Jie; Liu Guo Zhi

    2002-01-01

    An experimental set-up is developed to measure the characteristics of semiconductor opening switch (SOS). The parameters, such as interruption impedance, current int eruption time, voltage gain, pulse duration and energy transfer efficiency, are studied experimentally. The experimental results show that forward pumping time and reverse pumping time are important parameters for semiconductor opening switches. The influences of forward pumping time and reverse pumping time on interruption time, voltage gain, and energy transfer efficiency are obtained. In the interruption process, the impedance variation is divided into three phases: that is rapid increasing phase, slow change phase and completely interruption phase

  4. Enhancement Mode Power Switching AlGaN HEMTs

    Science.gov (United States)

    2013-05-14

    the highest recorded off- state breakdown voltage for an AlGaN/ GaN HEMT device with a relatively small gate-drain spacing and no field plate...3. DATES COVERED (From - To) 03/01/2010-12/31/2012 4. TITLE AND SUBTITLE Enhancement Mode Power Switching AIGaN HEMTs 5a. CONTRACT NUMBER...AISiN is a preferred dielectric for high voltage AIGaN HEMTs for power switching applications. The grate-source capacitance will compare favorably

  5. Perancangan Switch Matrik Besar Menggunakan Array Switch Analog Zarlink

    OpenAIRE

    2009-01-01

    Secara tradisional, perancangan sebuah switch matrik yang besar dilakukan dengan menggunakan switch-switch elektromekanik. Dengan demikian, banyak bagian yang bergerak yang digunakan untuk membangun switch matrik ini. Dengan kemajuan bidang elektronik, switch elektromekanik saat ini dapat digantikan dengan switch-switch semikonduktor yang ekivalen yang menawarkan solusi yang lebih ekonomis dan memiliki keandalan yang lebih baik. Rumpun switch crosspoint analog Zarlink dapat disusun dengan mud...

  6. 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.

  7. 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.

  8. Shot number estimation for EB direct writing for logic LSI utilizing character-build standard-cell layout technique

    Science.gov (United States)

    Kajiya, Yoshihiko; Nakamura, Akihiro; Yoshikawa, Masaya; Fujino, Takeshi

    2006-05-01

    Electron Beam direct writing (EBDW) technology is the most cost-effective lithography tool for small-volume logic-LSI fabrication. The EB exposure time will be greatly reduced by applying character-projection (CP) aperture. But the applicable number of CP aperture is limited to 25-400 depending upon EB lithography apparatus. The cell-based logic LSIs are composed of standard-cells (SCs) whose number is 400-1000. Therefore, it is impossible to implement all SCs as CP apertures, because the SCs are placed to 4-directions in general. We had proposed the new technique named 'Character-Build (CB) standard-cell', and demonstrate the most of the combination-logic SCs can be composed by only 17 CP apertures. In this paper, not only combination-logic SCs but also sequential-logic SCs are considered. The number of EB-shots and the chip-area are estimated for some sample circuits. Compared to the simply-limited SCs, The EB shot number is 30-40% reduced by using proposed CB standard-cell, when the CP aperture numbers are 20-30. Moreover, CB standard-cell was advantageous in the module area. Considering 2-directional placement of SCs, the combination of the EB apparatus with 50-100 CP apertures and the CB standard-cell technique may be the best method for high-speed EB direct-writing.

  9. Protective effects of ebselen (Ebs) and para-aminosalicylic acid (PAS) against manganese (Mn)-induced neurotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Marreilha dos Santos, A.P., E-mail: apsantos@ff.ul.pt [I-Med.UL, Department of Toxicology and Food Sciences, Faculty of Pharmacy, University of Lisbon, Lisbon (Portugal); Lucas, Rui L.; Andrade, Vanda; Mateus, M. Luísa [I-Med.UL, Department of Toxicology and Food Sciences, Faculty of Pharmacy, University of Lisbon, Lisbon (Portugal); Milatovic, Dejan; Aschner, Michael [Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232 (United States); Batoreu, M. Camila [I-Med.UL, Department of Toxicology and Food Sciences, Faculty of Pharmacy, University of Lisbon, Lisbon (Portugal)

    2012-02-01

    Chronic, excessive exposure to manganese (Mn) may induce neurotoxicity and cause an irreversible brain disease, referred to as manganism. Efficacious therapies for the treatment of Mn are lacking, mandating the development of new interventions. The purpose of the present study was to investigate the efficacy of ebselen (Ebs) and para-aminosalicylic acid (PAS) in attenuating the neurotoxic effects of Mn in an in vivo rat model. Exposure biomarkers, inflammatory and oxidative stress biomarkers, as well as behavioral parameters were evaluated. Co-treatment with Mn plus Ebs or Mn plus PAS caused a significant decrease in blood and brain Mn concentrations (compared to rats treated with Mn alone), concomitant with reduced brain E{sub 2} prostaglandin (PGE{sub 2}) and enhanced brain glutathione (GSH) levels, decreased serum prolactin (PRL) levels, and increased ambulation and rearing activities. Taken together, these results establish that both PAS and Ebs are efficacious in reducing Mn body burden, neuroinflammation, oxidative stress and locomotor activity impairments in a rat model of Mn-induced toxicity. -- Highlights: ► The manuscript is unique in its approach to the neurotoxicity of Mn. ► The manuscript incorporates molecular, cellular and functional (behavioral) analyses. ► Both PAS and Ebs are effective in restoring Mn behavioral function. ► Both PAS and Ebs are effective in reducing Mn-induced oxidative stress. ► Both PAS and Ebs led to a decrease in Mn-induced neuro-inflammation.

  10. A Switched Capacitor Based AC/DC Resonant Converter for High Frequency AC Power Generation

    Directory of Open Access Journals (Sweden)

    Cuidong Xu

    2015-09-01

    Full Text Available A switched capacitor based AC-DC resonant power converter is proposed for high frequency power generation output conversion. This converter is suitable for small scale, high frequency wind power generation. It has a high conversion ratio to provide a step down from high voltage to low voltage for easy use. The voltage conversion ratio of conventional switched capacitor power converters is fixed to n, 1/n or −1/n (n is the switched capacitor cell. In this paper, A circuit which can provide n, 1/n and 2n/m of the voltage conversion ratio is presented (n is stepping up the switched capacitor cell, m is stepping down the switching capacitor cell. The conversion ratio can be changed greatly by using only two switches. A resonant tank is used to assist in zero current switching, and hence the current spike, which usually exists in a classical switching switched capacitor converter, can be eliminated. Both easy operation and efficiency are possible. Principles of operation, computer simulations and experimental results of the proposed circuit are presented. General analysis and design methods are given. The experimental result verifies the theoretical analysis of high frequency AC power generation.

  11. Negative-resistance voltage-current characteristics of superconductor contact junctions for macro-scale applications

    CERN Document Server

    Takayasu, M; Minervini, J V; 10.1109/TASC.2003.812854

    2003-01-01

    Voltage-current characteristics of mechanical pressure contact junctions between superconducting wires are investigated using a voltage-driving method. It is found that the switching regions at low voltages result from negative resistance of the contact junction. The current transport of the contact junctions is discussed from the perspective of two existing models: the multiple Andreev reflections at the two SN interfaces of a SNS (Superconductor/Normal metal /Superconductor) junction and the inhomogeneous multiple Josephson weak-link array. (13 refs).

  12. High Voltage Distribution

    Science.gov (United States)

    Norbeck, Edwin; Miller, Michael; Onel, Yasar

    2010-11-01

    For detector arrays that require 5 to 10 kV at a few microamps each for hundreds of detectors, using hundreds of HV power supplies is unreasonable. Bundles of hundreds of HV cables take up space that should be filled with detectors. A typical HV module can supply 1 ma, enough current for hundreds of detectors. It is better to use a single HV module and distribute the current as needed. We show a circuit that, for each detector, measures the current, cuts off the voltage if the current exceeds a set maximum, and allows the HV to be turned on or off from a control computer. The entire array requires a single HV cable and 2 or 3 control lines. This design provides the same voltage to all of the detectors, the voltage set by the single HV module. Some additional circuitry would allow a computer controlled voltage drop between the HV and each individual detector.

  13. 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.

  14. Voltage-controlled nanoscale reconfigurable magnonic crystal

    Science.gov (United States)

    Wang, Qi; Chumak, Andrii V.; Jin, Lichuan; Zhang, Huaiwu; Hillebrands, Burkard; Zhong, Zhiyong

    2017-04-01

    A nanoscale reconfigurable magnonic crystal is designed using voltage-controlled perpendicular magnetic anisotropy (PMA) in ferromagnetic-dielectric heterostructures. A periodic array of gate metallic strips is placed on top of a MgO/Co structure in order to apply a periodic electric field and to modify the PMA in Co. It is numerically demonstrated that the introduction of PMA, which can be realized experimentally via applying a voltage, modifies the spin-wave propagation and leads to the formation of band gaps in the spin-wave spectrum. The band gaps can be controlled, i.e., it is possible to switch band gaps on and off within a few tens of nanoseconds. The width and the center frequency of the band gaps are defined by the applied voltage. Finally, it is shown that the introduction of PMA to selected, rather than to all gate strips allows for a predefined modification of the band-gap spectra. The proposed voltage-controlled reconfigurable magnonic crystal opens a way to low power consumption magnonic applications.

  15. High voltage engineering fundamentals

    CERN Document Server

    Kuffel, E; Hammond, P

    1984-01-01

    Provides a comprehensive treatment of high voltage engineering fundamentals at the introductory and intermediate levels. It covers: techniques used for generation and measurement of high direct, alternating and surge voltages for general application in industrial testing and selected special examples found in basic research; analytical and numerical calculation of electrostatic fields in simple practical insulation system; basic ionisation and decay processes in gases and breakdown mechanisms of gaseous, liquid and solid dielectrics; partial discharges and modern discharge detectors; and over

  16. Low-voltage gyrotrons

    Science.gov (United States)

    Glyavin, M. Yu.; Zavolskiy, N. A.; Sedov, A. S.; Nusinovich, G. S.

    2013-03-01

    For a long time, the gyrotrons were primarily developed for electron cyclotron heating and current drive of plasmas in controlled fusion reactors where a multi-megawatt, quasi-continuous millimeter-wave power is required. In addition to this important application, there are other applications (and their number increases with time) which do not require a very high power level, but such issues as the ability to operate at low voltages and have compact devices are very important. For example, gyrotrons are of interest for a dynamic nuclear polarization, which improves the sensitivity of the nuclear magnetic resonance spectroscopy. In this paper, some issues important for operation of gyrotrons driven by low-voltage electron beams are analyzed. An emphasis is made on the efficiency of low-voltage gyrotron operation at the fundamental and higher cyclotron harmonics. These efficiencies calculated with the account for ohmic losses were, first, determined in the framework of the generalized gyrotron theory based on the cold-cavity approximation. Then, more accurate, self-consistent calculations for the fundamental and second harmonic low-voltage sub-THz gyrotron designs were carried out. Results of these calculations are presented and discussed. It is shown that operation of the fundamental and second harmonic gyrotrons with noticeable efficiencies is possible even at voltages as low as 5-10 kV. Even the third harmonic gyrotrons can operate at voltages about 15 kV, albeit with rather low efficiency (1%-2% in the submillimeter wavelength region).

  17. On-chip High-Voltage Generator Design

    CERN Document Server

    Tanzawa, Toru

    2013-01-01

    This book describes high-voltage generator design with switched-capacitor multiplier techniques.  The author provides various design techniques for switched-capacitor on-chip high-voltage generators, including charge pump circuits, regulators, level shifters, references, and oscillators.  Readers will see these techniques applied to system design in order to address the challenge of how the on-chip high-voltage generator is designed for Flash memories, LCD drivers, and other semiconductor devices to optimize the entire circuit area and power efficiency with a low voltage supply, while minimizing the cost.   ·         Shows readers how to design charge pump circuits with lower voltage operation, higher power efficiency, and smaller circuit area; ·         Describes comprehensive circuits and systems design of on-chip high-voltage generators; ·         Covers all the component circuit blocks, including charge pumps, pump regulators, level shifters, oscillators, and references.

  18. High-voltage pulsed generator for dynamic fragmentation of rocks.

    Science.gov (United States)

    Kovalchuk, B M; Kharlov, A V; Vizir, V A; Kumpyak, V V; Zorin, V B; Kiselev, V N

    2010-10-01

    A portable high-voltage (HV) pulsed generator has been designed for rock fragmentation experiments. The generator can be used also for other technological applications. The installation consists of low voltage block, HV block, coaxial transmission line, fragmentation chamber, and control system block. Low voltage block of the generator, consisting of a primary capacitor bank (300 μF) and a thyristor switch, stores pulse energy and transfers it to the HV block. The primary capacitor bank stores energy of 600 J at the maximum charging voltage of 2 kV. HV block includes HV pulsed step up transformer, HV capacitive storage, and two electrode gas switch. The following technical parameters of the generator were achieved: output voltage up to 300 kV, voltage rise time of ∼50 ns, current amplitude of ∼6 kA with the 40 Ω active load, and ∼20 kA in a rock fragmentation regime (with discharge in a rock-water mixture). Typical operation regime is a burst of 1000 pulses with a frequency of 10 Hz. The operation process can be controlled within a wide range of parameters. The entire installation (generator, transmission line, treatment chamber, and measuring probes) is designed like a continuous Faraday's cage (complete shielding) to exclude external electromagnetic perturbations.

  19. Influence of pulse line switch inductance on output characteristics of high-current nanosecond accelerators

    Science.gov (United States)

    Mashchenko, A. I.; Vintizenko, I. I.

    2016-06-01

    Various types of high-current nanosecond accelerators are simulated numerically using an equivalent circuit representation. The influence of pulse forming line switch inductance on the amplitude and waveform of output voltage and current pulses is analyzed.

  20. Simple Switching Strategy for High-Torque Control Performance utilizing Neutral Point Clamped Multilevel Inverter

    Directory of Open Access Journals (Sweden)

    Nor Faezah Alias

    2013-12-01

    Full Text Available Three-level Neutral Point Clamped (NPC inverter allows the configuration of switching devices to operate at high voltage and produce lower current/voltage harmonics. It is known that, DTC of induction machine which employs hysteresis controller has major drawbacks namely larger torque ripple and variable switching frequency. This paper aims to propose a suitable voltage vector selection to provide better torque regulation and lower switching frequency by employing DTC with 3-level NPC multilevel inverter. A simple switching strategy was formulated using 7-level torque hysteresis and 2-level flux hysteresis controllers to give more options in selecting an appropriate voltage vector, inherently, according the motor operation conditions. The improvements offered were verified through simulations.