WorldWideScience

Sample records for breakers circuit

  1. Short- circuit tests of circuit breakers

    OpenAIRE

    Chorovský, P.

    2015-01-01

    This paper deals with short-circuit tests of low voltage electrical devices. In the first part of this paper, there are described basic types of short- circuit tests and their principles. Direct and indirect (synthetic) tests with more details are described in the second part. Each test and principles are explained separately. Oscilogram is obtained from short-circuit tests of circuit breakers at laboratory. The aim of this research work is to propose a test circuit for performing indirect test.

  2. Arc modelling in SF6 circuit breakers

    International Nuclear Information System (INIS)

    The paper presents the work done by an operator, EDF and two manufacturers to improve the physical models and numerical methods used to simulate the behavior of the plasma and cold gas around it in a breaking chamber of the HV SF6 circuit breaker, during the high-current phase. This work concerns flow phenomena, in particular incorporating compressibility and the study of turbulence, the coupling between these flow phenomena and electromagnetic phenomena, and finally, radiation - which plays an essential role in energy transfer during the high-current phase. For this latter aspect, emission but also absorption were proven to play a major role, and the two were introduced into the models. The paper presents the models developed and the results obtained with them for simulation of two circuit breaker mock-ups (a double-pressure circuit breaker mock-up and a self-expanding and rotating arc circuit breaker mock-up). (author)

  3. 30 CFR 77.904 - Identification of circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Identification of circuit breakers. 77.904... COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.904 Identification of circuit breakers. Circuit breakers shall be labeled to show which circuits they control unless identification...

  4. 46 CFR 169.670 - Circuit breakers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Circuit breakers. 169.670 Section 169.670 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and... for— (a) Inverse time delay; (b) Instantaneous short circuit protection; and (c) Repeated opening...

  5. 30 CFR 75.904 - Identification of circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Identification of circuit breakers. 75.904 Section 75.904 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... Alternating Current Circuits § 75.904 Identification of circuit breakers. Circuit breakers shall be marked...

  6. 30 CFR 75.800 - High-voltage circuits; circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 75.800... § 75.800 High-voltage circuits; circuit breakers. High-voltage circuits entering the underground area of any coal mine shall be protected by suitable circuit breakers of adequate interrupting...

  7. 30 CFR 77.800 - High-voltage circuits; circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 77.800... COAL MINES Surface High-Voltage Distribution § 77.800 High-voltage circuits; circuit breakers. High-voltage circuits supplying power to portable or mobile equipment shall be protected by suitable...

  8. Transient Ablation Regime in Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    Alexandre MARTIN; Jean-Yves TREPANIER; Marcelo REGGIO; GUO Xue-yan

    2007-01-01

    Nozzle wall ablation caused by high temperature electric arcs is studied in the context of high voltage SF6 circuit breakers.The simplified ablation model used in litterature has been updated to take into account the unsteady state of ablation.Ablation rate and velocity are now calculated by a kinetic model using two layers of transition,between the bulk plasma and the ablating wall.The first layer (Knudsen layer),right by the wall,is a kinetic layer of a few mean-free path of thickness.The second layer is collision dominated and makes the transition between the kinetic layer and the plasma bulk.With this new coupled algorithm,it is now possible to calculate the temperature distribution inside the wall,as well as more accurate ablation rates.

  9. 30 CFR 75.601-1 - Short circuit protection; ratings and settings of circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection; ratings and settings of circuit breakers. 75.601-1 Section 75.601-1 Mineral Resources MINE SAFETY AND HEALTH... Trailing Cables § 75.601-1 Short circuit protection; ratings and settings of circuit breakers....

  10. Arc modelling in SF{sub 6} circuit breakers

    Energy Technology Data Exchange (ETDEWEB)

    Verite, J.C. [Electricite de France, Clamart (France). Derection des Etudes et Recherches; Boucher, T.; Comte, A. [Electricite de France, Moret sur Loing (France). Direction des Etudes et Recherches; Delalondre, C. [Electricite de France, Chatou (France). Direction des Etudes et Recherches; Robin-Jouan, P.; Serres, E.; Texier, V. [GEC Alsthom, Villeurbanne (France). Direction Technique Haute et Moyenne Tension; Barrault, M.; Chevrier, P.; Fievet, C. [CEA Centre d`Etudes Nucleaires de Grenoble, 38 (France). Merlin Gerin

    1995-06-01

    The paper presents the work done by an operator, EDF and two manufacturers to improve the physical models and numerical methods used to simulate the behavior of the plasma and cold gas around it in a breaking chamber of the HV SF6 circuit breaker, during the high-current phase. This work concerns flow phenomena, in particular incorporating compressibility and the study of turbulence, the coupling between these flow phenomena and electromagnetic phenomena, and finally, radiation - which plays an essential role in energy transfer during the high-current phase. For this latter aspect, emission but also absorption were proven to play a major role, and the two were introduced into the models. The paper presents the models developed and the results obtained with them for simulation of two circuit breaker mock-ups (a double-pressure circuit breaker mock-up and a self-expanding and rotating arc circuit breaker mock-up). (author) 10 refs.

  11. Evaluation of generator circuit breaker applications / J.F. Fourie.

    OpenAIRE

    Fourie, Johannes Frederick

    2010-01-01

    The use of generator circuit breakers in power stations was investigated and evaluated. A feasibility study to determine if the additional capital cost required, when using a generator circuit breaker in a power station could be justified by the advantages it provides. The background to the study is provided through a technology and literature survey. Included in the technology review and the literature study is information on interruption mediums, the historic developments ...

  12. Development, integration and testing of automated triggering circuit for hybrid DC circuit breaker

    International Nuclear Information System (INIS)

    A novel concept of Hybrid DC circuit breaker having combination of mechanical switch and static switch provides arc-less current commutation into the dump resistor during quench in superconducting magnet operation. The triggering of mechanical and static switches in Hybrid DC breaker can be automatized which can effectively reduce the overall current commutation time of hybrid DC circuit breaker and make the operation independent of opening time of mechanical switch. With this view, a dedicated control circuit (auto-triggering circuit) has been developed which can decide the timing and pulse duration for mechanical switch as well as static switch from the operating parameters. This circuit has been tested with dummy parameters and thereafter integrated with the actual test set up of hybrid DC circuit breaker. This paper deals with the conceptual design of the auto-triggering circuit, its control logic and operation. The test results of Hybrid DC circuit breaker using this circuit have also been discussed. (author)

  13. Age-related degradation of Westinghouse 480-volt circuit breakers

    International Nuclear Information System (INIS)

    An aging assessment of Westinghouse DS-series low-voltage air circuit breakers was performed as part of the Nuclear Plant Aging Research (NPAR) program. The objectives of this study are to characterize age-related degradation within the breaker assembly and to identify maintenance practices to mitigate their effect. Since this study has been promulgated by the failures of the reactor trip breakers at the McGuire Nuclear Station in July 1987, results relating to the welds in the breaker pole lever welds are also discussed. The design and operation of DS-206 and DS-416 breakers were reviewed. Failure data from various national data bases were analyzed to identify the predominant failure modes, causes, and mechanisms. Additional operating experiences from one nuclear station and two industrial breaker-service companies were obtained to develop aging trends of various subcomponents. The responses of the utilities to the NRC Bulletin 88-01, which discusses the center pole lever welds, were analyzed to assess the final resolution of failures of welds in the reactor trips. Maintenance recommendations, made by the manufacturer to mitigate age-related degradation were reviewed, and recommendations for improving the monitoring of age-related degradation are discussed. As described in Volume 2 of this NUREG, the results from a test program to assess degradation in breaker parts through mechanical cycling are also included. The testing has characterized the cracking of center-pole lever welds, identified monitoring techniques to determine aging in breakers, and provided information to augment existing maintenance programs. Recommendations to improve breaker reliability using effective maintenance, testing, and inspection programs are suggested. 13 refs., 21 figs., 8 tabs

  14. Switching Surge Analysis of Vacuum Circuit Breaker using EMTP

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ik Mo; Kim, Ji Hong [Hyundai Heavy Industry, Mechatronics Research Institute (Korea)

    2000-07-01

    The first objective of this study is to set up the switching surge analysis method in motor driving distribution system. The simplified model which can simulate the motor energization and circuit breaker re-ignitions, and each circuit element model is presented in this paper. The second objective is to calculate the quantity of surge over-voltage in real nuclear power station. And the surge suppressing measures are verified on the simulation basis. It is clarified that most cases are not satisfactory to meet the IEEE standard 522-1992 without using surge suppressing measures. In cases that the surge arrester are installed in distribution board at the load side of circuit breaker. The IEEE specification is fully met. (author). 6 refs., 4 figs., 3 tabs.

  15. Increasing of Switching Abilities of High Voltage Circuit Breakers

    OpenAIRE

    RUSTEMLI, Sabir

    2015-01-01

    The most effective way of increasing switching abilities of high voltage circuit breakers in energy transmission systems is to influence around zero degree to short circuit currents (Maljkovic Z et al 2000; Gashimov, A.M et al. 2001;Antipov, K.M et al. 1985; Gashimov A.M 1991). For this reason, transformers neutral points should be grounded variously for limitation of asymmetric short circuit currents. But another way for this limitation is grounded of transformers neutral points over non-lin...

  16. Assessment and modelling of switching technologies for application in HVDC-circuit breakers

    OpenAIRE

    Lund, Johan

    2011-01-01

    A key element for future DC-grids is a DC circuit breaker that in case of a short circuit fault reliably can turn off a short circuit current. AC circuit breakers are well known components that has been in use for a long time in AC-grids. The AC circuit breaker is designed to interrupt the current at its natural current zero crossings. In DC grids such does not exists, therefore AC breakers can not be directly applied in DC grids. Different concepts and technologies to solve this problem is a...

  17. Calculation and comparison of circuit breaker parameters in Power World Simulator

    Directory of Open Access Journals (Sweden)

    Kuljinder Kaur,

    2016-01-01

    Full Text Available A circuit breaker has ratings that an engineer uses for their application. These ratings define circuit breaker performance characteristics. A good understanding of Ratings allow the electrical engineer to make a proper comparison of various circuit breaker designs. In this research work, the different ratings of circuit breaker were calculated. The other objective of this work was comparison between ratings of existing circuit breaker and calculated ratings in POWER WORLD SIMULATOR. Further, the impact of time delay in circuit breaker was studied. These calculations were performed for rated current of 400 & 630 Amps. The results performed in POWER WORLD SIMULATOR were shown better and information gained from the analysis can be used for proper relay selection, settings, performances and coordination.

  18. An Overview of Dynamic Contact Resistance Measurement of HV Circuit Breakers

    Science.gov (United States)

    Bhole, A. A.; Gandhare, W. Z.

    2016-06-01

    With the deregulation of the electrical power industry, utilities and service companies are operating in a changing business environment. High voltage circuit breakers are extremely important for the function of modern electric power supply systems. The need to predict the proper function of circuit breaker grew over the years as the transmission networks expanded. The maintenance of circuit breakers deserves special consideration because of their importance for routine switching and for protection of other equipments. Electric transmission system breakups and equipment destruction can occur if a circuit breaker fails to operate because of a lack of preventive maintenance. Dynamic Contact Resistance Measurement (DCRM) is known as an effective technique for assessing the condition of power circuit breakers contacts and operating mechanism. This paper gives a general review about DCRM. It discusses the practical case studies on use of DCRM for condition assessment of high voltage circuit breakers.

  19. Reliability centered maintenance of power transformers and circuit breakers

    Energy Technology Data Exchange (ETDEWEB)

    Purucker, S.L.; Goeltz, R.T. [Oak Ridge National Lab., TN (United States); Hemmelman, K.; Price, R. [Bonneville Power Administration, Van Couver, WA (United States)

    1992-08-01

    At the Bonneville Power Administration (BPA), we have historically maintained high voltage equipment. Including transformers and power circuit breakers, on a time driven basis. While this has served our needs in the past, newer methods are needed to effectively maintain the power system in future years. Today aging equipment, maintenance backlogs, and budget constraints are a reality. BPA has initiated a research and development project to examine reliability centered maintenance (RCM) as an alternative to time based maintenance on high voltage equipment. Under RCM, the performance of each place of equipment is to be monitored by observing many operating parameters. For example, with circuit breakers we will observe (measure) the trip time, accumulated contact wear using I{sup 2}T, timing of the mechanism, plus several other parameters. Equipment performing below a predetermined level, or equipment having accumulated a large amount of ``usage`` will receive maintenance. The maintenance will restore full performance and preserve an acceptable service life for that piece of equipment. To develop and evaluate RCM concepts, BPA is installing a prototype system at our Alvey Substation on 4 transformers and 25 breakers.

  20. Study on the instantaneous protection reliability of low voltage circuit breakers

    Institute of Scientific and Technical Information of China (English)

    LU Jian-guo; DU Tai-hang; LUO Yan-yan

    2007-01-01

    This paper outlines the significance of enhancing the instantaneous protection reliability of low voltage circuit breakers and describes their main failure modes. The instantaneous failure mechanism of low voltage circuit breakers was analyzed so that measures to improve instantaneous protection reliability can be determined. Furthermore, the theory of the instantaneous characteristics Calibration device for low voltage circuit breakers and the method of eliminating the non-periodic component of test current are given in detail. Finally, the test results are presented.

  1. Approaching the Processes in the Generator Circuit Breaker at Disconnection through Sustainability Concepts

    OpenAIRE

    Carmen A. Bulucea; Nikos E. Mastorakis; Doru A. Nicola; Marc A. Rosen; Cornelia A. Bulucea

    2013-01-01

    Nowadays, the electric connection circuits of power plants (based on fossil fuels as well as renewable sources) entail generator circuit-breakers (GCBs) at the generator terminals, since the presence of that electric equipment offers many advantages related to the sustainability of a power plant. In an alternating current (a.c.) circuit the interruption of a short circuit is performed by the circuit-breaker at the natural passing through zero of the short-circuit current. During the current i...

  2. Age-related degradation of Westinghouse 480-volt circuit breakers

    International Nuclear Information System (INIS)

    After the McGuire event in 1987 relating to failure of the center pole weld in one of its reactor trip breakers, activities were initiated by the NRC to investigate the probable causes. A review of operating experience suggested that the burning of coils, jamming of the operating mechanism, and deterioration of the contacts dominated the breakers failures. Although failures of the pole shaft weld were not included as one of the generic problems, the NRC augmented inspection team had suspected that these welds were substandard which led them to crack prematurely. A DS-416 low voltage air circuit breaker manufactured by Westinghouse was mechanically cycled to identify age-related degradations. This accelerated aging test was conducted for over 36,000 cycles during nine months. Three separate pole shafts, one with a 60 degree weld, one with a 120 degree and one with a 180 degree were used to characterize the cracking in the pole level welds. In addition, three different operating mechanisms and several other parts were replaced as they became inoperable. The testing yielded many useful results. The burning of the closing coils was found to be the effect of binding in the linkages that are connected to this device. Among the seven welds on the pole shaft, number-sign 1 and number-sign 3 were the critical ones which cracked first to cause misalignment of the pole levers, which, in turn, had led to many problems with the operating mechanism including the burning of coils, excessive wear in certain parts, and overstressed linkages. Based on these findings, a maintenance program is suggested to alleviate the age-related degradations that occur due to mechanical cycling of this type of breaker. 3 refs., 39 figs., 7 tabs

  3. Investigation of a circuit breaker for the ASDEX fusion experiment at Garching

    International Nuclear Information System (INIS)

    In fusion experiments electric discharges are produced in the plasma by interrupting high currents in the ohmic heating coils using fast and powerful circuit breakers. Thereby high plasma currents are induced which heat the plasma. Results obtained with a standard circuit breaker capable of interrupting 30 kA at 20 kV are reported here. The lifetime of the breaker contacts is investigated. (orig.)

  4. Experimental and theoretical analysis of vacuum circuit breaker prestrike effect on a transformer

    NARCIS (Netherlands)

    Popov, M.; Smeets, R.P.P.; Van der Sluis, L.; De Herdt, H.; Declerq, J.

    2009-01-01

    The work presented in this paper deals with the investigation of circuit breaker prestrike effect that occurs during energizing a distribution transformer. An experimental test setup that consists of a supply transformer, a vacuum circuit breaker (VCB), a cable and a test transformer is built, and t

  5. Fault current limiter with solid-state circuit breakers

    Science.gov (United States)

    Bălan, H.; Neamț, L.; Buzdugan, M. I.; Varodi, T.; Pop, E.

    2016-08-01

    Switching of power circuit breakers is an important technical issue, especially at short circuit, since the fault current cause thermal and dynamic stresses, and the power quality worsens. Recently, the development of distributed renewable electricity induces the short circuit protection problematic because the distributed production of electric energy cause the transport networks to lose their radial character and disturbs the protective relays coordination. The modern technologies for power switching uses static fault current limiters, which offers a viable solution to remove the problems caused by large fault currents in the system. An appropriate design of the current limiting device reduces the thermal and dynamic stress and limits the fault current to a low value. The static switches are based on high power semiconductor devices that offer advantages compared to mechanical switches. Using a fault current limiter that minimizes the effect of distributed generation of electricity in a radial network on the co-ordination of protective relays is a solution to this problem in terms of switching speed and lifespan of power switches.

  6. Dedicating Finite Volume Method to Electromagnetic Plasma Modeling: Circuit Breaker Application

    OpenAIRE

    Rondot, Loïc; Mazauric, Vincent; Delannoy, Yves; Meunier, Gérard

    2009-01-01

    For several applications including strong hydrodynamics constraints (like in a circuit breaker), Finite Element solvers are not suitable for fluid dynamical modeling. For these applications, the coupling between the Computational Fluid Dynamics and the electromagnetism modeling is not easy. In this context, a magnetodynamic formulation is developed using the Finite Volume Method to address specific issues in multiphysics involved in circuit breaker modeling. The principles of Finite Volume Me...

  7. Experimental and theoretical analysis of vacuum circuit breaker prestrike effect on a transformer

    OpenAIRE

    Popov, M.; Smeets, RPP René; Sluis, van der, B.J.; Herdt, de, H; Declercq, J.

    2009-01-01

    The work presented in this paper deals with the investigation of circuit breaker prestrike effect that occurs during energizing a distribution transformer. An experimental test setup that consists of a supply transformer, a vacuum circuit breaker (VCB), a cable and a test transformer is built, and the prestrikes in the VCB are recorded. The test transformer is a prototype distribution transformer, with installed measuring points along transformer windings in each phase. Voltage oscillations a...

  8. CFD Simulation of Transonic Flow in High-Voltage Circuit Breaker

    OpenAIRE

    Xiangyang Ye; Mahesh Dhotre

    2012-01-01

    A high-voltage circuit breaker is an indispensable piece of equipment in the electric transmission and distribution systems. Transonic flow typically occurs inside breaking chamber during the current interruption, which determines the insulating characteristics of gas. Therefore, accurate compressible flow simulations are required to improve the prediction of the breakdown voltages in various test duties of high-voltage circuit breakers. In this work, investigation of the impact of the solver...

  9. Biocompatible circuit-breaker chip for thermal management of biomedical microsystems

    Science.gov (United States)

    Luo, Yi; Dahmardeh, Masoud; Takahata, Kenichi

    2015-05-01

    This paper presents a thermoresponsive micro circuit breaker for biomedical applications specifically targeted at electronic intelligent implants. The circuit breaker is micromachined to have a shape-memory-alloy cantilever actuator as a normally closed temperature-sensitive switch to protect the device of interest from overheating, a critical safety feature for smart implants including those that are electrothermally driven with wireless micro heaters. The device is fabricated in a size of 1.5  ×  2.0  ×  0.46 mm3 using biocompatible materials and a chip-based titanium package, exhibiting a nominal cold-state resistance of 14 Ω. The breaker rapidly enters the full open condition when the chip temperature exceeds 63 °C, temporarily breaking the circuit of interest to lower its temperature until chip temperature drops to 51 °C, at which the breaker closes the circuit to allow current to flow through it again, physically limiting the maximum temperature of the circuit. This functionality is tested in combination with a wireless resonant heater powered by radio-frequency electromagnetic radiation, demonstrating self-regulation of heater temperature. The developed circuit-breaker chip operates in a fully passive manner that removes the need for active sensor and circuitry to achieve temperature regulation in a target device, contributing to the miniaturization of biomedical microsystems including electronic smart implants where thermal management is essential.

  10. Biocompatible circuit-breaker chip for thermal management of biomedical microsystems

    International Nuclear Information System (INIS)

    This paper presents a thermoresponsive micro circuit breaker for biomedical applications specifically targeted at electronic intelligent implants. The circuit breaker is micromachined to have a shape-memory-alloy cantilever actuator as a normally closed temperature-sensitive switch to protect the device of interest from overheating, a critical safety feature for smart implants including those that are electrothermally driven with wireless micro heaters. The device is fabricated in a size of 1.5  ×  2.0  ×  0.46 mm3 using biocompatible materials and a chip-based titanium package, exhibiting a nominal cold-state resistance of 14 Ω. The breaker rapidly enters the full open condition when the chip temperature exceeds 63 °C, temporarily breaking the circuit of interest to lower its temperature until chip temperature drops to 51 °C, at which the breaker closes the circuit to allow current to flow through it again, physically limiting the maximum temperature of the circuit. This functionality is tested in combination with a wireless resonant heater powered by radio-frequency electromagnetic radiation, demonstrating self-regulation of heater temperature. The developed circuit-breaker chip operates in a fully passive manner that removes the need for active sensor and circuitry to achieve temperature regulation in a target device, contributing to the miniaturization of biomedical microsystems including electronic smart implants where thermal management is essential. (paper)

  11. Vacuum Dielectric Recovery Characteristics of a Novel Current Limiting Circuit Breaker Base on Artificial Current Zero

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhuangxian; ZHUANG Jinwu; WANG Chen; WU Jin; LIU Luhui

    2012-01-01

    A novel current limiting circuit breaker employs zero current switching method in cutting off DC current, which gives out a reverse impulsive current towards a high speed vacuum interrupter and force the current down to zero. This kind of breaker is simply in structure and can act in a very short time with high current limiting capability, and therefore it has a long electric life and is extremely suitable to be installed in a DC electrical system as a fault orotection utility.

  12. Research on current sharing of paralleled IGBTs in different DC breaker circuit topologies

    Directory of Open Access Journals (Sweden)

    Chen Ying

    2016-01-01

    Full Text Available IGBT modules used in series and parallel to satisfy the requirement in high-power DC circuit breakers are often prone to large-current destruction due to current unbalance between paralleled IGBTs. It is of great importance to identify the current unbalance causes and to find a method optimizing the current sharing of paralleled IGBTs. In this paper the current-sharing influencing factors are discussed and verified by simulation. Two possible circuit topologies used in DC circuit breakers are proposed and simulated to see their performance in current sharing. The results show that one of them can provide us with a simple and effective method to achieve good current balancing in the DC circuit breaker application.

  13. Study of the cost reduction possibilities on the secondary equipment of SION Vacuum Circuit Breaker from Siemens AG

    OpenAIRE

    Gil González, Alba

    2011-01-01

    The aim of this Master Thesis is to make a study of the cost reduction possibilities of the secondary equipment of SION Vacuum Circuit Breaker from Siemens AG. The secondary equipment of a circuit breaker consists of several auxiliary devices –usually electronic- which are necessary for operating and controlling the breaker. Regarding the most important requirements for the new M3 price driven market which are Price reduction and Standard technology, a study on the current situation and...

  14. Analysis of cold flow reestablishment time in a circuit breaker nozzle

    Science.gov (United States)

    Leone, S. A.; Nagamatsu, H. T.

    1983-01-01

    The deblocking process in a circuit breaker nozzle is similar to the flow starting process in a shock tunnel, and the computer uses this analogy to solve for the deblocking process by utilizing a diaphragm at the throat of a nozzle. At time equal to zero the diaphragm is broken and the throat area increases with time. It is a rarity to have the area as a function of both time and distance. Experimental data obtained from the RPI calibration shock tunnel are utilized to verify some of the calculated results with the area being a function of distance and the agreement is found to be good. The circuit breaker designer can utilize the computer simulation to estimate the deblocking time, an important parameter in the design of circuit breakers.

  15. CFD Simulation of Transonic Flow in High-Voltage Circuit Breaker

    Directory of Open Access Journals (Sweden)

    Xiangyang Ye

    2012-01-01

    Full Text Available A high-voltage circuit breaker is an indispensable piece of equipment in the electric transmission and distribution systems. Transonic flow typically occurs inside breaking chamber during the current interruption, which determines the insulating characteristics of gas. Therefore, accurate compressible flow simulations are required to improve the prediction of the breakdown voltages in various test duties of high-voltage circuit breakers. In this work, investigation of the impact of the solvers on the prediction capability of the breakdown voltages in capacitive switching is presented. For this purpose, a number of compressible nozzle flow validation cases have been presented. The investigation is then further extended for a real high-voltage circuit breaker geometry. The correlation between the flow prediction accuracy and the breakdown voltage prediction capability is identified.

  16. Approaching the Processes in the Generator Circuit Breaker at Disconnection through Sustainability Concepts

    Directory of Open Access Journals (Sweden)

    Carmen A. Bulucea

    2013-03-01

    Full Text Available Nowadays, the electric connection circuits of power plants (based on fossil fuels as well as renewable sources entail generator circuit-breakers (GCBs at the generator terminals, since the presence of that electric equipment offers many advantages related to the sustainability of a power plant. In an alternating current (a.c. circuit the interruption of a short circuit is performed by the circuit-breaker at the natural passing through zero of the short-circuit current. During the current interruption, an electric arc is generated between the opened contacts of the circuit-breaker. This arc must be cooled and extinguished in a controlled way. Since the synchronous generator stator can flow via highly asymmetrical short-circuit currents, the phenomena which occur in the case of short-circuit currents interruption determine the main stresses of the generator circuit-breaker; the current interruption requirements of a GCB are significantly higher than for the distribution network circuit breakers. For shedding light on the proper moment when the generator circuit-breaker must operate, using the space phasor of the short-circuit currents, the time expression to the first zero passing of the short-circuit current is determined. Here, the manner is investigated in which various factors influence the delay of the zero passing of the short-circuit current. It is shown that the delay time is influenced by the synchronous machine parameters and by the load conditions which precede the short-circuit. Numerical simulations were conducted of the asymmetrical currents in the case of the sudden three-phase short circuit at the terminals of synchronous generators. Further in this study it is emphasized that although the phenomena produced in the electric arc at the terminals of the circuit-breaker are complicated and not completely explained, the concept of exergy is useful in understanding the physical phenomena. The article points out that just after the short-circuit

  17. Moisture Sensor for Sulfur Hexafluoride (SF6)-filled Circuit Breakers; FINAL

    International Nuclear Information System (INIS)

    Measurements at ORNL were made on the Kahn moisture sensor which Doble Engineering wants to evaluate for use in SF(sub 6) circuit breakers. Test conducted at ORNL indicate that vacuum conditions, as might be found in SF(sub 6) circuit breakers prior to filling with SF(sub 6), could lead to significant changes in calibration, resulting in erroneous readings of moisture content. Similar effects might also be observed in cases where SF(sub 6) byproducts are present, due the reactivity of some of these byproducts with water

  18. Pressure and Arc Voltage Measurement in a 252 kV SF6 Puffer Circuit Breaker

    Science.gov (United States)

    Zhong, Jianying; Guo, Yujing; Zhang, Hao

    2016-05-01

    The pressure distribution in an arcing chamber is critically important for the SF6 puffer circuit breaker design. In this paper, the pressure variation of four locations in the nozzle was measured by piezoresistive and fiber optical pressure sensors at two current levels of 10 kA and 50 kA. An arc voltage measurement was also taken. The results demonstrate that using either type of sensor with a connecting tube is able to detect the fast pressure variation in circuit breakers, however the possible distortion and delay to the pressure transient caused by the tube need further study.

  19. Pressure and Arc Voltage Measurement in a 252 kV SF6 Puffer Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    ZHONG Jianying; GUO Yujing; ZHANG Hao

    2016-01-01

    The pressure distribution in an arcing chamber is critically important for the SF6 puffer circuit breaker design.In this paper,the pressure variation of four locations in the nozzle was measured by piezoresistive and fiber optical pressure sensors at two current levels of 10 kA and 50 kA.An arc voltage measurement was also taken.The results demonstrate that using either type of sensor with a connecting tube is able to detect the fast pressure variation in circuit breakers,however the possible distortion and delay to the pressure transient caused by the tube need further study.

  20. Research on The Mechanical State Parameter Extraction Method of High Voltage Circuit Breakers

    Directory of Open Access Journals (Sweden)

    Yang Tianxu

    2013-05-01

    Full Text Available High voltage circuit breakers play an important role in the power system. So it is necessary to implement the state detection of breakers in order to ensure stable and reliable running of the grid. The purpose of state detection is to provide reliable basis of maintenance by extracting mechanical state parameters accurately. This paper mainly focuses on the coil current signal feature extraction algorithm. To settle the problem of too much noise mixed with the current signal and signal distortion, the discrete wavelet transform algorithm is used to extract the coil current signal parameters. This paper also designs the FIR filter to extract stroke and speed parameters from travel-time waveform. The experiments show that the difference between the theoretical results and test results processed by the method in this paper is very small and the test results are able to accurately reflect operation states and mechanical features of high voltage circuit breakers.

  1. The Implications of the Use of Parental Choice as a Legal "Circuit Breaker"

    Science.gov (United States)

    Mead, Julie F.; Lewis, Maria M.

    2016-01-01

    This study explores four instances where parental choice has been employed as a legal "circuit breaker": (a) First Amendment Establishment Clause cases related to public funding, (b) Fourteenth Amendment Equal Protection cases regarding race-conscious student assignment, (c) Title IX regulations concerning single-sex education, and (d) a…

  2. Online Monitoring System Design of Intelligent Circuit Breaker Based on DSP and ARM

    Directory of Open Access Journals (Sweden)

    Meng Song

    2014-08-01

    Full Text Available In order to accurately analyze the dynamic characteristics of the vacuum circuit breaker, a dual-core master-slave processor structure for online monitoring system based on DSP and ARM is proposed. This structure consists of host computer, lower computer and signal processing modules. The lower computer uses DSP as the core, which completes acquisition and data preprocessing of circuit breaker’s dynamic characteristics through sensors and signal conditioning circuits. The host computer uses ARM as the core which is responsible for task management, analysis, processing and displaying collected data via Ethernet. The communication between DSP and ARM is conducted by HPI. This design improves the reliability of intelligent control unit for the circuit breaker. The experiment showed that this system works steadily and accuracy.

  3. Numerical Simulation of Gas Flow During Arcing Process for 252 kV Puffer Circuit Breakers%Numerical Simulation of Gas Flow During Arcing Process for 252 kV Puffer Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    吴军辉; 王小华; 马志瀛; 荣命哲; 闫静

    2011-01-01

    A numerical simulation model for 252 kV puffer circuit breaker is constructed, by using a proven commercial computational fluid dynamics (CFD) package, PHOENICS. The model takes into account the moving parts in the circuit breaker, turbulence enhanced momentum and energy transport, radiation transport. The arcing process in a SF6 puffer circuit breaker with two hollow contacts is simulated under different conditions, and the simulation results are verified with experimental results. Through simulation, the pressure, temperature and velocity in the arc quenching chamber can be obtained. The simulation model is also capable of predicting the influence of design parameters variations on breaker performance, and can thus help to reduce the number of short-circuit tests during the design stage.

  4. Mechanical Fault Diagnosis for HV Circuit Breakers Based on Ensemble Empirical Mode Decomposition Energy Entropy and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Jianfeng Zhang

    2015-01-01

    Full Text Available During the operation process of the high voltage circuit breaker, the changes of vibration signals can reflect the machinery states of the circuit breaker. The extraction of the vibration signal feature will directly influence the accuracy and practicability of fault diagnosis. This paper presents an extraction method based on ensemble empirical mode decomposition (EEMD. Firstly, the original vibration signals are decomposed into a finite number of stationary intrinsic mode functions (IMFs. Secondly, calculating the envelope of each IMF and separating the envelope by equal-time segment and then forming equal-time segment energy entropy to reflect the change of vibration signal are performed. At last, the energy entropies could serve as input vectors of support vector machine (SVM to identify the working state and fault pattern of the circuit breaker. Practical examples show that this diagnosis approach can identify effectively fault patterns of HV circuit breaker.

  5. Research on the overload protection reliability of moulded case circuit-breakers and its test device

    Institute of Scientific and Technical Information of China (English)

    LI Kui; LU Jian-guo; WU Yi; QIN Zhi-jun; YAO Dong-mei

    2007-01-01

    This paper analyzed the reliability and put forward the reliability index of overload protection for moulded case circuit breaker. The success rate was adopted as its reliability index of overload protection. Based on the reliability index and the reliability level, the reliability examination plan was analyzed and a test device for the overload protection of moulded case circuit-breaker was developed. In the reliability test of overload protection, two power sources were used, which reduced the time of conversion and regulation between two different test currents in the overload protection test, which made the characteristic test more accurate. The test device was designed on the base of a Windows system, which made its operation simple and friendly.

  6. Transient simulation of nozzle geometry change during ablation in high-voltage circuit breakers

    International Nuclear Information System (INIS)

    In high voltage circuit breakers, radiated heat from the electric arc is strongly absorbed by surrounding poly-tetra-fluro-ethylene (PTFE) parts and causes them to reach their vaporization temperature and ablate. Ablation deforms the PTFE parts, widens the throat and hence, changes the nozzle geometry. This paper presents a physical model coupling plasma flow simulation with erosion and movement of the PTFE walls to study this phenomena. The model is first applied and validated on a segmented tube case and on a model SF6 circuit breaker for which the experimental data is available. Then, the model is used to investigate the effect of the surface ablation on the nozzle geometry in a long-operation time. (paper)

  7. Dynamic Simulation and Opening Bouncing Analysis of Vacuum Circuit Breaker with Permanent Magnetic Actuator

    Institute of Scientific and Technical Information of China (English)

    LIN Xin; CAO Chen; LI Bin; LIU Yang; XU Jianyuan

    2013-01-01

    In order to research the dynamic characteristics of circuit breaker (CB) in opening process,taking a 12 kV vacuum circuit breaker (VCB) with permanent magnetic actuator as the example,a dynamic model of the VCB is established based on the virtual prototype technology,and dynamic equations of the model are deduced.Simulation and experiment are carried out on the VCB of both opening and closing processes.The simulative opening time and closing time are 39.5 ms and 54.6 ms respectively.Influencing factors of opening bouncing and their effect principles are analyzed through dynamic simulations of opening bouncing process.Analytic results indicate that the increase in the stiffness coefficient of contact spring limits the opening bouncing; meanwhile increases in the preload of contact spring and the mass of shaft can enlarge the opening bouncing.

  8. Effect of Circuit Breaker Shunt Resistance on Chaotic Ferroresonance in Voltage Transformer

    Directory of Open Access Journals (Sweden)

    RADMANESH, H.

    2010-08-01

    Full Text Available Ferroresonance or nonlinear resonance is a complex electrical phenomenon, which may cause over voltages and over currents in the electrical power system which endangers the system reliability and continuous safe operating. This paper studies the effect of circuit breaker shunt resistance on the control of chaotic ferroresonance in a voltage transformer. It is expected that this resistance generally can cause ferroresonance dropout. For confirmation this aspect Simulation has been done on a one phase voltage transformer rated 100VA, 275kV. The magnetization characteristic of the transformer is modeled by a single-value two-term polynomial with q=7. The simulation results reveal that considering the shunt resistance on the circuit breaker, exhibits a great mitigating effect on ferroresonance over voltages. Significant effect on the onset of chaos, the range of parameter values that may lead to chaos along with ferroresonance voltages has been obtained and presented.

  9. IMPROVEMENT OF TRANSIENT STABILITY OF POWER SYSTEM USING SOLID STATE CIRCUIT BREAKER

    OpenAIRE

    Kalai Murugan Amirthalingam; Raja Prabu Ramachandran

    2013-01-01

    The aim of this study is to use a solid state circuit breaker for the improvement of transient stability margin. Long distance AC transmission is often subject to stability problems, which limits the transmission capability. Interconnected power systems suffer from weakly damped swings between synchronous generator and sub systems. The development of modern power system has lead to an increasing complexity in the study of power system and also presents new challenges to power system stability...

  10. A Novel Approach to Power Circuit Breaker Design for Replacement of SF6

    Directory of Open Access Journals (Sweden)

    D. J. Telfer

    2004-01-01

    Full Text Available This contribution explores the role of PTFE ablation in enhancing current interruption for various background gases in high voltage circuit breakers. An assessment of the current interruption capability has been made in terms of the arcing duration and the contact gap length at which critical arc extinction is achieved. These observations are supported by measurements of the magnitude of extinction and re-ignition voltage peaks. Most previous and other current experimental work on gas filled circuit breaker design follows conventional wisdom in investigating arcing behaviours at elevated gas pressures (usually up to 6 bar. But in this work we concentrate on the effects of using low gas pressures (less than 1 bar in the presence of a close-fitting shield of ablatant polymer material (PTFE that surrounds the electrode assembly of an experimental high power circuit breaker. We demonstrate that for several different gases, arc extinction capability compares well under these conditions with SF6, suggesting that SF6 could be replaced entirely in this novel system by more environmentally friendly gases. Moreover, the critical contact gap lengths at extinction are only slightly greater than when using SF6 at 6 bar. Weight loss measurements from the ablatant shield suggest that a chemical puffer action is the most likely mechanism for achieving the observed arc extinctions in this system.

  11. IMPROVEMENT OF TRANSIENT STABILITY OF POWER SYSTEM USING SOLID STATE CIRCUIT BREAKER

    Directory of Open Access Journals (Sweden)

    Kalai Murugan Amirthalingam

    2013-01-01

    Full Text Available The aim of this study is to use a solid state circuit breaker for the improvement of transient stability margin. Long distance AC transmission is often subject to stability problems, which limits the transmission capability. Interconnected power systems suffer from weakly damped swings between synchronous generator and sub systems. The development of modern power system has lead to an increasing complexity in the study of power system and also presents new challenges to power system stability and in particular to the aspects of transient stability and small signal stability. Transient stability control plays a significant role in ensuring the stable operation of power systems in the event of large disturbances and faults and is thus a significant area of research. This study investigates the improvement of transient stability of a two area system, using Solid State Circuit Breaker which is capable of fast switching in case of faults and thus controlling the real and reactive power flows in a faulted transmission line. Simulations are carried out in Matlab/Simulink environment for two area system model with Solid State Circuit Breaker to analyze the effects of SSCB on transient stability performance of the system. From the simulation results, swing curves of the three phase faulted power system without SSCB gets increases monotonically and thus the system can be considered as unstable whereas the swing curves of the system with an SSCB reaches to a steady state.

  12. Fuzzy Diagnostic System for Oleo-Pneumatic Drive Mechanism of High-Voltage Circuit Breakers

    Directory of Open Access Journals (Sweden)

    Viorel Nicolau

    2013-01-01

    Full Text Available Many oil-based high-voltage circuit breakers are still in use in national power networks of developing countries, like those in Eastern Europe. Changing these breakers with new more reliable ones is not an easy task, due to their implementing costs. The acting device, called oleo-pneumatic mechanism (MOP, presents the highest fault rate from all components of circuit breaker. Therefore, online predictive diagnosis and early detection of the MOP fault tendencies are very important for their good functioning state. In this paper, fuzzy logic approach is used for the diagnosis of MOP-type drive mechanisms. Expert rules are generated to estimate the MOP functioning state, and a fuzzy system is proposed for predictive diagnosis. The fuzzy inputs give information about the number of starts and time of functioning per hour, in terms of short-term components, and their mean values. Several fuzzy systems were generated, using different sets of membership functions and rule bases, and their output performances are studied. Simulation results are presented based on an input data set, which contains hourly records of operating points for a time horizon of five years. The fuzzy systems work well, making an early detection of the MOP fault tendencies.

  13. Study on Restrike Phenomena for 40.5-kV Vacuum Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    Yan Jing; Ma Zhiying

    2006-01-01

    When interrupting short circuit fault by 40.5-Kv vacuum circuit breakers, it is significant to eliminate multiple restrike phenomena, which occur frequently and result in high overvoltage and even interruption failure. A synthetic circuit that can supply a DC recovery voltage after current zero was used to study multiple restrike phenomena in switching. Some key factors including breaking current, clearance between open contacts, electrode structure and contact material, which may affect restrike characteristics, were studied. Under various clearances, the statistical probability of restrike was obtained. As a result, the best scope of clearance between open contacts was found. The performance of CuCrS0/50 and CuCr75/25 material were compared. Two kinds of electrode structures, namely 1/2 coil structure and cup-shaped axial magnetic structure, were tested. After a high-current interruption, conditioning effect was realized and the probability ofrestrike decreased.

  14. Transient Studies in Large Offshore Wind Farms, Employing Detailed Circuit Breaker Representation

    DEFF Research Database (Denmark)

    Glasdam, Jakob Bærholm; Bak, Claus Leth; Hjerrild, Jesper

    2012-01-01

    in order to ensure reliable switching operations. Transient measurement results in an OWF are compared with simulation results in PSCAD EMTDC and DigSILENT Power Factory. A user-defined model of the vacuum circuit breaker (VCB) is included in both tools, capable of simulating multiple prestrikes during...... the closing operation. An analysis of the switching transients that might occur in OWFs will be made on the basis of the validated model, and the importance of the inclusion of a sufficiently accurate representation of the VCB in the simulation tool will be described. The inclusion of the VCB model in PSCAD...

  15. Transient studies in large offshore wind farms, taking into account network/circuit breaker interaction

    DEFF Research Database (Denmark)

    Glasdam, Jacob Bærholm; Bak, Claus Leth; Hjerrild, Jesper;

    2011-01-01

    to ensure reliable switching operations. Transient measurement results in an OWF are compared with simulation results in PSCAD EMTDC and DigSILENT Power Factory, where a user-defined model of the vacuum circuit breaker (VCB) is included, capable of simulating multiple prestrikes during the closing operation....... An analysis of the switching transients that might occur in an OWF will be made on basis of the validated model and the importance of the inclusion of a sufficient accurate representation of the VCB in the simulation tool will be described. The inclusion of the VCB model in PSCAD greatly improves...

  16. Simulation of the Effects of Several Factors on Arc Plasma Behavior in Low Voltage Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Taking into account the properties of the arc plasma and the electromagnetic, heat and radiative phenomena, commercial computational fluid dynamics software PHOENICS has been adapted and modified to develop the three-dimensional magneto-hydrodynamic (MHD)model of arc in a low voltage circuit breaker. The effects of the arc ignition location, venting size and gassing material on arc behavior have been investigated. The analysis of the results show that the arc velocity accelerates with the increase in the distance between arc ignition location and of the venting size, and the existence of the gassing material is beneficial to improving the arc voltage and reducing the arc temperature.

  17. Study on the Mathematical Model of Dielectric Recovery Characteristics in High Voltage SF6 Circuit Breaker

    Science.gov (United States)

    Lin, Xin; Wang, Feiming; Xu, Jianyuan; Xia, Yalong; Liu, Weidong

    2016-03-01

    According to the stream theory, this paper proposes a mathematical model of the dielectric recovery characteristic based on the two-temperature ionization equilibrium equation. Taking the dynamic variation of charged particle's ionization and attachment into account, this model can be used in collaboration with the Coulomb collision model, which gives the relationship of the heavy particle temperature and electron temperature to calculate the electron density and temperature under different pressure and electric field conditions, so as to deliver the breakdown electric field strength under different pressure conditions. Meanwhile an experiment loop of the circuit breaker has been built to measure the breakdown voltage. It is shown that calculated results are in conformity with experiment results on the whole while results based on the stream criterion are larger than experiment results. This indicates that the mathematical model proposed here is more accurate for calculating the dielectric recovery characteristic, it is derived from the stream model with some improvement and refinement and has great significance for increasing the simulation accuracy of circuit breaker's interruption characteristic. supported by Science and Technology Project of State Grid Corporation of China (No. GY17201200063), National Natural Science Foundation of China (No. 51277123), Basic Research Project of Liaoning Key Laboratory of Education Department (LZ2015055)

  18. Study of switching electric circuits with DC hybrid breaker, one stage

    Science.gov (United States)

    Niculescu, T.; Marcu, M.; Popescu, F. G.

    2016-06-01

    The paper presents a method of extinguishing the electric arc that occurs between the contacts of direct current breakers. The method consists of using an LC type extinguishing group to be optimally sized. From this point of view is presented a theoretical approach to the phenomena that occurs immediately after disconnecting the load and the specific diagrams are drawn. Using these, the elements extinguishing group we can choose. At the second part of the paper there is presented an analyses of the circuit switching process by decomposing the process in particular time sequences. For every time interval there was conceived a numerical simulation model in MATLAB-SIMULINK medium which integrates the characteristic differential equation and plots the capacitor voltage variation diagram and the circuit dumping current diagram.

  19. Improving Transient Recovery voltage of circuit breaker using Fault Current Limiter

    Directory of Open Access Journals (Sweden)

    Amir Heidary

    2012-12-01

    Full Text Available This study investigates influence of Fault Current Limiter (FCL on short-circuits current level of substation bus bar splitter circuit breaker and its TRV. An approach for TRV evaluation is developed and applied for proposed power system as shown in this study. FCL circuit is connected to the power system in order to limit TRV. The limiter circuit consists of two equal windings which are turned around unique magnetic core. One of the windings is connected in series with the power system network and the other is connected to the network via series capacitor and power electronic switches. During normal operating condition, both tyristors are in on state and current of the primary and secondary windings are equal. This causes zero impedance of the limiter. During fault, faults current cause the power electronic switch to turn off which increases the limiter impedance. By increasing the limiter impedance, amplitude of TRV decreases substantially. The novel method presented in this study is a cheap and successful scheme.

  20. Power nanosecond pulse shaping by means of RCD-generators with peaking circuits based on diode current breakers

    CERN Document Server

    Grekhov, I V; Korotkov, S V; Stepanyants, A L; Khristyuk, D V

    2002-01-01

    One considered the basic principles to design nanosecond region generators based on reverse-connected dynistos (RCD) with diode current breaker base output peaking circuits. Paper presents the results of experimental investigation in intense generator based on RCD, peaking pulsed transformer and high-voltage diode breaker from a set of series-connected drift diodes with abrupt reset. Generator at 1 kHz frequency commutates voltage pulses with approx 45 kV amplitude, approx 50 ns duration and approx 10 ns rise front to 25 ohm load

  1. Plasma circuit breaker in a magnetic field as a high-power ion flux generator

    International Nuclear Information System (INIS)

    It is ascertained that plasma circuit breaker (PCB) in the external magnetic field of acute-anguled geometry in the mode when PCB serves as inductive storage loading is a natural magnetoizolated diode. Using PCB as an ion emitter and as a high-voltage generator it proved possible in case of full electron magnetiuzation to attain the maximum efficiency of the storage. The density of ion current evaluated by the measured energy density for 30 J/cm2 thermocouple and by the energy of 1.5 MeV constitutes 100 A/cm2. The given method of ion generation is very effective when high ion currents with a high energy are required

  2. The Influence of Contact Space on Arc Commutation Process in Air Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    NIU Chunping; DING Juwen; YANG Fei; DONG Delong; RONG Mingzhe; XU Dan

    2016-01-01

    In this paper,a 3D magneto-hydrodynamic (MHD) arc simulation model is applied to analyze the arc motion during current interruption in a certain air circuit breaker (ACB).The distributions of pressure,temperature,gas flow and current density of the arc plasma in the arc region are calculated,and the factors influencing the commutation process are analyzed according to the calculated results.Based on the airflow in the arc chamber,the causes of arc commutation asynchrony and the back commutation are investigated.It indicates that a reasonable contact space design is crucial to a successful arc commutation process.To verify the simulation results,the influence of contact space on arc voltage and arc commutation is tested.This research can provide methods and references to the optimization of ACB design.

  3. Reduction of Switching Surge by Controlled Shunt Reactor Switching of Gas Circuit Breaker

    Science.gov (United States)

    Kohyama, Haruhiko; Ito, Hiroki; Asai, Jun; Hidaka, Mikio; Yonezawa, Takashi

    Controlled switching system (CSS) with a 204kV gas circuit breaker (GCB) demonstrates to reduce an inrush current and to eliminate re-ignitions in shunt reactor switching. Target closing and opening instants for controlled switching are determined by the electrical and mechanical characteristics of GCB. Idle time dependence of the operating time, which gives a sufficient impact on controlling accuracy, is evaluated and successfully compensated by synchronous switching controller (SSC). Field operation of CSS for a year shows an effective suppression of inrush current on closing and prevention of re-ignitions on opening of shunt reactor. The operations also proved that the CSS has a satisfactory performance for electro-magnetic disturbance imposed in practical field.

  4. New Breakdown Electric Field Calculation for SF6 High Voltage Circuit Breaker Applications

    Institute of Scientific and Technical Information of China (English)

    Ph.ROBIN-JOUAN; M.YOUSFI

    2007-01-01

    The critical electric fields of hot SF6 are calculated including both electron and ion kinetics in wide ranges of temperature and pressure,namely from 300 K up to 4000 K and 2 atmospheres up to 32 atmospheres respectively.Based on solving a multi-term electron Boltzmann equation the calculations use improved electron-gas collision cross sections for twelve SF6 dissociation products with a particular emphasis on the electron-vibrating molecule interactions.The ion kinetics is also considered and its role on the critical field becomes non negligible as the temperature is above 2000 K.These critical fields are then used in hydrodynamics simulations which correctly predict the circuit breaker behaviours observed in the case of breaking tests.

  5. Power ion beam production in a magnetic-insulated diode placed in a circuit with an inductive storage with a plasmoerosion circuit breaker

    International Nuclear Information System (INIS)

    Consideration is given to results of experimental studies of modes of operation of plasma current breaker and magnetic insulated diode, placed parallel in a circuit with inductive storage and microsecond generator, as well as parameters of high-power ion beam, generated in gas-filled diode. Magnetic field of mirror configuration, which enabled to locate the gas-filled diode dose to breaking region was used for decrease of electrodynamic plasma transfer. It is shown that time delay (of the order of ten and more) of power maximum in gas-filled diode with respect to power maximum in plasma breaker is observed when using passive plasma source on anode

  6. Vacuum interrupter, high reliability component of distribution switches, circuit breakers and contactors

    Institute of Scientific and Technical Information of China (English)

    SLADE Paul G.; LI Wang-pei; MAYO Stephen; SMITH R.Kirkland; TAYLOR Erik D.

    2007-01-01

    The use of vacuum interrupters (VIs) as the current interruption component for switches, circuit breakers, reclosers and contactors operating at distribution voltages has escalated since their introduction in the mid-1950's. This electrical product has developed a dominating position for switching and protecting distribution circuits. VIs are even being introduced into switching products operating at transmission voltages. Among the reasons for the VI's popularity are its compactness, its range of application, its low cost, its superb electrical and mechanical life and its ease of application. Its major advantage is its well-established reliability. In this paper we show how this reliability has been achieved by design, by mechanical life testing and by electrical performance testing. We introduce the "sealed for life" concept for the VI's integrity. We discuss this in terms of what is meant by a practical leak rate for VIs with a life of over 30 years. We show that a simple high voltage withstand test is an easy and effective method for monitoring the long-term vacuum integrity. Finally we evaluate the need for routine inspection of this electrical product when it is used in adverse ambient environments.

  7. Current identification in vacuum circuit breakers as a least squares problem*

    Directory of Open Access Journals (Sweden)

    Ghezzi Luca

    2013-01-01

    Full Text Available In this work, a magnetostatic inverse problem is solved, in order to reconstruct the electric current distribution inside high voltage, vacuum circuit breakers from measurements of the outside magnetic field. The (rectangular final algebraic linear system is solved in the least square sense, by involving a regularized singular value decomposition of the system matrix. An approximated distribution of the electric current is thus returned, without the theoretical problem which is encountered with optical methods of matching light to temperature and finally to current density. The feasibility is justified from the computational point of view as the (industrial goal is to evaluate whether, or to what extent in terms of accuracy, a given experimental set-up (number and noise level of sensors is adequate to work as a “magnetic camera” for a given circuit breaker. Dans cet article, on résout un problème inverse magnétostatique pour déterminer la distribution du courant électrique dans le vide d’un disjoncteur à haute tension à partir des mesures du champ magnétique extérieur. Le système algébrique (rectangulaire final est résolu au sens des moindres carrés en faisant appel à une décomposition en valeurs singulières regularisée de la matrice du système. On obtient ainsi une approximation de la distribution du courant électrique sans le problème théorique propre des méthodes optiques qui est celui de relier la lumière à la température et donc à la densité du courant. La faisabilité est justifiée d’un point de vue numérique car le but (industriel est d’évaluer si, ou à quelle précision, un dispositif expérimental donné (nombre et seuil limite de bruit des senseurs peut travailler comme une “caméra magnétique” pour un certain disjoncteur.

  8. Analytical Analysis and Case Study of Transient Behavior of Inrush Current in Power Transformer for Designing of Efficient Circuit Breakers

    Science.gov (United States)

    Harmanpreet, Singh, Sukhwinder; Kumar, Ashok; Kaur, Parneet

    2010-11-01

    Stability & security are main aspects in electrical power systems. Transformer protection is major issue of concern to system operation. There are many mall-trip cases of transformer protection are caused by inrush current problems. The phenomenon of transformer inrush current has been discussed in many papers since 1958. In this paper analytical analysis of inrush current in a transformer switched on dc and ac supply has been done. This analysis will help in design aspects of circuit breakers for better performance.

  9. Simulation and Experimental Study of Arc Column Expansion After Ignition in Low-Voltage Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    MA Qiang; RONG Mingzhe; WU Yi; XU Tiejun; SUN Zhiqiang

    2008-01-01

    The dynamicprocess of arc pressure and corresponding arc column expansion, which is the main feature after arc ignition and has a significant effect on the breaking behaviour of low -voltage circuit breakers, is studied. By constructing a three dimensional mathematical model of air arc plasma and adopting the Control Volume Method, the parameters of arc plasma including temperature and pressure axe obtained. The variations of pressure field and temperature field with time are simulated. The result indicates that there are six stages for the process of arc column expansion according to the variation of pressure in arc chamber. In the first stage, the maximal pressure locates in the region close to cathode, and in the second stage the maximal pressure shifts to the region close to the anode. In the third stage, the pressure difference between the middle of arc column and the ambient gas is very large, so the arc column begins to expand apparently. In the fourth stage, the pressure wave propagates towards both ends and the maximal pressure appears at the two ends when the pressure wave reaches both sidewalls. In the fifth stage, the pressure wave is reflected and collides in the middle of the arc chamber. In the last stage, the propagation and reflection of pressure wave will repeat several times until a steady burning state is reached. In addition, the experimental results of arc column expansion, corresponding to the arc pressure variation, are presented to verify the simulation results.

  10. Influence of Copper Vapor on Low-Voltage Circuit Breaker Arcs During Stationary and Moving States

    Institute of Scientific and Technical Information of China (English)

    MA Qiang; RONG Mingzhe; WU Yi; XU Tiejun; SUN Zhiqiang

    2008-01-01

    The influence of copper vapor on the low-voltage circuit breaker arcs is studied. A three-dimensional (3-D) magnetohydrodynamics(MHD) model of arc motion under the effect of external magnetic field is built up. By adopting the commercial computational fluid dynamics (CFD) package FLUENT based on control-volume method, the above MHD model is solved. For the mediums of air-1% Cu and air-10% Cu, the distributions of stationary temperature, pressure, electrical potential and the arc motion processes are compared with those of a pure air arc. The copper vapor diffusion process in the arc chamber and the distribution of copper vapor mass concentration are also simulated. The results shows that the copper vapor has a cooling effect on the arc plasma and can decrease the stationary voltage as well. Moreover, the presence of copper vapor can decelerate the arc motion in the quenching chambers. The maximal copper vapor concentration locates behind the arc root because of the existence of a "double vortex" near the electrodes.

  11. Numerical Study on Arc Plasma Behavior During Arc Commutation Process in Direct Current Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    杨飞; 马瑞光; 吴翊; 孙昊; 纽春萍; 荣命哲

    2012-01-01

    This paper focuses on the numerical investigation of arc plasma behavior during arc commutation process in a medium-voltage direct current circuit breaker (DCCB) contact system. A three-dimensional magneto-hydrodynamic (MHD) model of air arc plasma in the contact system of a DCCB is developed, based on commercial software FLUENT. Coupled electromagnetic and gas dynamic interactions are considered as usual, and a thin layer of nonlinear electrical resistance elements is used to represent the voltage drop of plasma sheath and the formation of new arc root. The distributions of pressure, temperature, gas flow and current density of arc plasma in arc region are calculated. The simulation results indicate that the pressure distribution related to the contact system has a strong effect on the arc commutation process, arising from the change of electrical conductivity in the arc root region. In DCCB contact system, the pressure of arc root region will be concentrated and higher if the space above the moving contact is enclosed, which is not good for arc root commutation. However, when the region is opened, the pressure distribution would be lower and more evenly, which is favorable for the arc root commutation.

  12. Calculation of Nozzle Ablation During Arcing Period in an SF6 Auto-Expansion Circuit Breaker

    Science.gov (United States)

    Zhang, Junmin; Lu, Chunrong; Guan, Yonggang; Liu, Weidong

    2016-05-01

    The nozzle ablation process is described as two phases of heat and ablation in the interruption for an SF6 circuit breaker in this paper. Their mathematical models are established with the Fourier heat conduction differential equation respectively. The masses of nozzle ablation with different arc durations and arc currents are calculated through the model of the nozzle ablation combined with an MHD (magneto-hydrodynamic) arc model. The time of the temperature rise on the inner surface of the nozzle under a given energy flux and of reaching the pyrolysis temperature under different energy fluxes is respectively analyzed. The relations between the mass of nozzle ablation and breaking current and arc duration are obtained. The result shows that the absorbing energy process before the nozzle ablation can be neglected under the condition of the energy flux entering into nozzle q > 109 W/m2. The ablation is the severest during the high-current phase and the ablation mass increases rapidly with the breaking current and with arc duration respectively. supported by National Natural Science Foundation of China (Nos. 51177005 and 51477004)

  13. Influence of a Circuit Breaker's Grading Capacitor on Controlled Transformer Switching

    Science.gov (United States)

    Corrodi, Yves; Kamei, Kenji; Kohyama, Haruhiko; Ito, Hiroki

    Controlled switching, taking into account the residual flux level within a transformer core, can effectively eliminate inrush currents. Many switching sequences assume the residual flux as a constant value, which can be obtained by a measurement after a transformer de-energization. However, in case of a transformer system that is switched by a circuit breaker equipped with a grading capacitor, the residual flux characteristic cannot be considered as constant. A source voltage will feed the deenergized transformer system through the grading capacitor, which will change the residual flux level and let oscillations appear. It follows that the optimal re-energization targets change and inrush currents might not be optimally minimized. Further, transient voltages based on line failures can influence the residual flux through a grading capacitor as well. At first, this paper evaluates the influence of a grading capacitor on the residual flux characteristic analytically. Further, measurements of two transformer systems at a varied de-energization instant and for different grading capacitors provide actual information for the development of future controller systems.

  14. Investigation of DC hybrid circuit breaker based on high-speed switch and arc generator

    Science.gov (United States)

    Wu, Yifei; Rong, Mingzhe; Wu, Yi; Yang, Fei; Li, Mei; Zhong, Jianying; Han, Guohui; Niu, Chunping; Hu, Yang

    2015-02-01

    A new design of DC hybrid circuit breaker based on high-speed switch (HSS) and arc generator (AG), which can drastically profit from low heat loss in normal state and fast current breaking under fault state, is presented and analyzed in this paper. AG is designed according to the magnetic pinch effect of liquid metal. By utilizing the arc voltage generated across AG, the fault current is rapidly commutated from HSS into parallel connected branch. As a consequence, the arcless open of HSS is achieved. The post-arc conducting resume time (Δ tc) of AG and the commutation original voltage (Uc), two key factors in the commutation process, are investigated experimentally. Particularly, influences of the liquid metal channel diameter (Φ) of AG, fault current rate of rise (di/dt) and Uc on Δ tc are focused on. Furthermore, a suitable Uc is determined during the current commutation process, aiming at the reliable arcless open of HSS and short breaking time. Finally, the fault current breaking test is carried out for the current peak value of 11.8 kA, and the validity of the design is confirmed by the experimental results.

  15. The Influence of Contact Space on Arc Commutation Process in Air Circuit Breaker

    Science.gov (United States)

    Niu, Chunping; Ding, Juwen; Yang, Fei; Dong, Delong; Rong, Mingzhe; Xu, Dan

    2016-05-01

    In this paper, a 3D magneto-hydrodynamic (MHD) arc simulation model is applied to analyze the arc motion during current interruption in a certain air circuit breaker (ACB). The distributions of pressure, temperature, gas flow and current density of the arc plasma in the arc region are calculated, and the factors influencing the commutation process are analyzed according to the calculated results. Based on the airflow in the arc chamber, the causes of arc commutation asynchrony and the back commutation are investigated. It indicates that a reasonable contact space design is crucial to a successful arc commutation process. To verify the simulation results, the influence of contact space on arc voltage and arc commutation is tested. This research can provide methods and references to the optimization of ACB design. supported by National Key Basic Research Program of China (973 Program) (Nos. 2015CB251002, 6132620303) and National Natural Science Foundation of China (Nos. 51221005, 51377128, 51577144), and Science and Technology Project Through Grid State Corporation (No. SGSNKYOOKJJS1501564)

  16. Calculation of Nozzle Ablation During Arcing Period in an SF6 Auto-Expansion Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    ZHANG Junmin; LU Chunrong; GUAN Yonggang; LIU Weidong

    2016-01-01

    The nozzle ablation process is described as two phases of heat and ablation in the interruption for an SF6 circuit breaker in this paper.Their mathematical models are established with the Fourier heat conduction differential equation respectively.The masses of nozzle ablation with different arc durations and arc currents are calculated through the model of the nozzle ablation combined with an MHD (magneto-hydrodynamic) arc model.The time of the temperature rise on the inner surface of the nozzle under a given energy flux and of reaching the pyrolysis temperature under different energy fluxes is respectively analyzed.The relations between the mass of nozzle ablation and breaking current and arc duration are obtained.The result shows that the absorbing energy process before the nozzle ablation can be neglected under the condition of the energy flux entering into nozzle q > 109 W/m2.The ablation is the severest during the high-current phase and the ablation mass increases rapidly with the breaking current and with arc duration respectively.

  17. Numerical Prediction on the Thermal Interrupting Capability of HV SF6 Gas Circuit Breakers%Numerical Prediction on the Thermal Interrupting Capability of HV SF6Gas Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    MU Jingwei; GUO Jin; DENG Xiang'e

    2013-01-01

    The design technology for HV SF6 gas circuit breakers is very demanding.A numerical method for prediction of the thermal interruption capability of SF6 gas circuit breakers is established based on the two-dimensional magneto-hydrodynamic (MHD) model and a commercial CFD(computational fluid dynamics) software,FLUENT.Nozzle ablation effect is considered by introducing an independent mass conservation equation for the ablated material to the overall conservation equations of mass,momentum,and energy.The ohmic heating and the radiation of the electric arc are considered in the model by adding relevant source terms.To predict the thermal interruption capability,the arc conductance 200 ns before current zero is used as an indicator.The CFD model is applied for the high current arcing phase,and Mayr arc model is used near the current zero period.The arc conductance at 200 ns before current zero(G200) for various arcing periods are computed by the present method.It shows that there exist a limit of the G200.For those whose arcing periods are within the arcing window,the related G200 are below the limit,therefore result a successful current interruption,and vice versa.The validation of the developed computer simulation tool is therefore verified.The numerical prediction by the simulation tool is verified by the direct interrupting test of 550 kV gas circuit breaker (GCB).The developed computer simulation tool was applied in the design of a 550 kV GCB.Significant benefits have been achieved in terms of both the cost saving and shorten of the development cycle.

  18. Technical-economic evaluation of the utilization of closing resistor in CEMIG extra-high voltage circuit breakers

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Angelica C.O.; Pinto, Roberto del Giudice R.; Teixeira, Jose Cleber; Fonseca, Rodrigo Assuncao; F. Junior, Sebastiao V. [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil)

    1994-12-31

    This paper presents the technical and economic studies performed by CEMIG, Companhia Energetica de Minas Gerais, Brazil, concerning the use of closing resistor in its extra-high voltage (EHV) breakers. The analysis emphasizes the advantages which could be achieved with the elimination of the resistor as far as costs and reliability are concerned. This evaluation was motivated by two 500 kV breaker failures resulting from the breakdown of the closing resistor operation mechanism. These occurrences resulted in operative restriction for CEMIG EHV system. The analysis demanded a review of the capability criteria of silicon carbide (Si C) gap arresters, which are still greatly used in CEMIG EHV System, and of the procedures to be applied when carrying out the transient studies. The investigation resulted in the prompt removal of closing resistors from circuit breakers in CEMIG extra-high voltage system generating an economy of approximately U$ 840,00 and an improvement in safety and system reliability. (author) 13 refs., 4 figs., 1 tab.

  19. Approach for electrodynamic force for compensation in low voltage circuit breaker WP 630-1.2 type

    Institute of Scientific and Technical Information of China (English)

    LU Na; XU L.J.; Miedzi(n)ski B.

    2007-01-01

    Undesirable repulsive force between contact members due to both a current path shrink near a real contact area and/or so-called pinch effect is particularly onerous for power switch applications, and results in either contact floating or bouncing which are associated with an electric arc following contact welding. This problem is of great importance for any circuit breaker especially for compact low voltage vacuum circuit breakers. To avoid contact floating at closure and during any inrush current under short circuit conditions, the electrodynamic repulsive force can be employed successfully if we use a special compensation system flexibly combined with the contact itself. However to select and design the compensation system properly, its efficiency has to be known. This paper presents an approach to obtain the electrodynamic force value depending on different shaped (rectangular,square, circle and arch) copper plates used in the compensator by using ANSYS for current values 40 kA RMS. Curve-fitting was done according to the calculating results, the optimization designing of compensation unit is based on them.

  20. Transient Studies in Large Offshore Wind Farms, Tak-ing Into Account Network/Circuit Breaker Interaction

    DEFF Research Database (Denmark)

    Glasdam, Jakob; Bak, Claus Leth; Hjerrild, Jesper;

    2011-01-01

    to ensure reliable switching operations. Transient measurement results in an OWF are compared with simulation results in PSCAD EMTDC and DigSILENT Power Factory, where a user-defined model of the vacuum circuit breaker (VCB) is included, capable of simulating multiple prestrikes during the closing operation....... An analysis of the switching transients that might occur in an OWF will be made on basis of the validated model and the importance of the inclusion of a sufficient accurate representation of the VCB in the simulation tool will be described. The inclusion of the VCB model in PSCAD greatly improves...

  1. Field Experiments on 10 kV Switching Shunt Capacitor Banks Using Ordinary and Phase-Controlled Vacuum Circuit Breakers

    OpenAIRE

    Wenxia Sima; Mi Zou; Qing Yang; Ming Yang; Licheng Li

    2016-01-01

    During the switching on/off of shunt capacitor banks in substations, vacuum circuit breakers (VCBs) are required to switch off or to switch on the capacitive current. Therefore, the VCBs have to be operated under a harsh condition to ensure the reliability of the equipment. This study presents a complete comparison study of ordinary and phase-controlled VCBs on switching 10 kV shunt capacitor banks. An analytical analysis for switching 10 kV shunt capacitor banks is presented on the basis of ...

  2. Transient Recovery Voltages at the Main 132kV Line Bay GIS Circuit Breaker in a Windfarm

    OpenAIRE

    Arana Aristi, Iván; Okholm, J.; Holbøll, Joachim

    2011-01-01

    This paper presents the results of investigations of the Transient Recovery Voltage (TRV) across the terminals of the main 132kV Line Bay GIS circuit breaker (GIS CB) for Walney 2, second phase of the Walney Offshore Wind Farm. Several simulations were performed where the influence of different parameters in the network was evaluated during a fault in the onshore substation. The rate of rise of recovery voltage (RRRV) and the maximum crest voltage (Uc) of the TRV across the GIS CB were compar...

  3. Simulation of the Process of Arc Energy-Effect in High Voltage Auto-Expansion SF6 Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    Rong Mingzhe; Yang Qian; Fan Chunduo

    2005-01-01

    A new magnetic hydro-dynamics (MHD) model of arc in H.V. auto-expansion SF6circuit breaker that takes into consideration nozzle ablation due to both radiation and thermal conduction is presented in this paper. The effect of PTFE (polytetrafluorethylene) vapor is considered in the mass, momentum and energy conservation equations of the constructed model. Then,the gas flow fields with and without conduction considered are simulated. By comparing the aforementioned two results, it is indicated that the arc's maximal temperature with conduction considered is 90 percent of that without considering conduction.

  4. Transient Recovery Voltages at the Main 132kV Line Bay GIS Circuit Breaker in a Windfarm

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Okholm, J.; Holbøll, Joachim

    2011-01-01

    parameters in the network was evaluated during a fault in the onshore substation. The rate of rise of recovery voltage (RRRV) and the maximum crest voltage (Uc) of the TRV across the GIS CB were compared against the standard values based on the type test results from the GIS. The investigations were......This paper presents the results of investigations of the Transient Recovery Voltage (TRV) across the terminals of the main 132kV Line Bay GIS circuit breaker (GIS CB) for Walney 2, second phase of the Walney Offshore Wind Farm. Several simulations were performed where the influence of different...

  5. Feasibility analysis of a novel hybrid-type superconducting circuit breaker in multi-terminal HVDC networks

    Science.gov (United States)

    Khan, Umer Amir; Lee, Jong-Geon; Seo, In-Jin; Amir, Faisal; Lee, Bang-Wook

    2015-11-01

    Voltage source converter-based HVDC systems (VSC-HVDC) are a better alternative than conventional thyristor-based HVDC systems, especially for developing multi-terminal HVDC systems (MTDC). However, one of the key obstacles in developing MTDC is the absence of an adequate protection system that can quickly detect faults, locate the faulty line and trip the HVDC circuit breakers (DCCBs) to interrupt the DC fault current. In this paper, a novel hybrid-type superconducting circuit breaker (SDCCB) is proposed and feasibility analyses of its application in MTDC are presented. The SDCCB has a superconducting fault current limiter (SFCL) located in the main current path to limit fault currents until the final trip signal is received. After the trip signal the IGBT located in the main line commutates the current into a parallel line where DC current is forced to zero by the combination of IGBTs and surge arresters. Fault simulations for three-, four- and five-terminal MTDC were performed and SDCCB performance was evaluated in these MTDC. Passive current limitation by SFCL caused a significant reduction of fault current interruption stress in the SDCCB. It was observed that the DC current could change direction in MTDC after a fault and the SDCCB was modified to break the DC current in both the forward and reverse directions. The simulation results suggest that the proposed SDCCB could successfully suppress the DC fault current, cause a timely interruption, and isolate the faulty HVDC line in MTDC.

  6. Analysis to Differences of Miniature Circuit Breakers Between EN and IEC Standard%解析小型断路器EN与IEC标准的差异

    Institute of Scientific and Technical Information of China (English)

    章晓艳

    2012-01-01

      Analysis and comparison were carried out for EN and IEC standard about circuit breakers for over-current protection used for household and similar site──circuit breakers for AC operation (miniature circuit breakers for short), EN 60898-1 and IEC 60898-1. In the aspects of product marking requirements, short-circuit test value quantity, tripping characteristic test of circuit breakers, energy losses clas-sification, this paper gave contents of main differences so as to provide references for related technical personnel.%  对欧盟、IEC 关于家用和类似场所用过电流保护断路器——用于交流的断路器(简称小型断路器)的标准 EN 60898-1、IEC 60898-1进行了分析比较,在产品标志要求、短路试验中试验量、断路器的脱扣特性试验、能耗等级分类等方面给出了主要差异内容,以供相关技术人员进行参考。

  7. Circuit-Breaker Lightning Accident Analysis Under Electrified State%热备用状态下的断路器雷击事故分析

    Institute of Scientific and Technical Information of China (English)

    王乃会; 邢大鹏; 汪德荣; 曾丽

    2012-01-01

    Via analysis to a burnt-down circuit-breaker accident taking place after certain substation undergoing lightning overvoltage, the main cause of circuit breakers undergoing lightning overvoltage damage under electrified state was that overvoltage all round radiation took place at the end of open circuit to make overvoltage raise in great scale. There are two ways such as to raise a circuit breaker itself with standing overvoltage capacity, to strengthen overvoltage protection and to strengthen safety and reliability of circuit breakers.%通过对某变电站遭受雷击过电压后发生的断路器烧毁事故进行分析,得出处于热备用状态下的断路器遭受雷电过电压损坏的主要原因是过电压在开路末端发生过电压全发射,造成过电压大幅度提高。可通过提高断路器本身耐受过电压能力和加强过电压保护两方面来加强断路器的安全性和可靠性。

  8. Summary of CIGRE 13.06 Working Group world wide reliability data and maintenence cost data on high voltage circuit breakers above 63 kV

    Energy Technology Data Exchange (ETDEWEB)

    Colombo, E.; Dialynas, E.; Heising, C.; Janssen, A.; Lanz, W.

    1995-06-01

    A summary is given of the most significant reliability data and maintenance cost data from the two CIGRE 13.06 Working Group world wide reliability surveys of the reliabilityof high voltage circuit breakers 63 kV and above. The first enquiry covered the years 1974 thru 1977 and included all interrupting technologies. The second enquiry covered the years 1988 thru 1991 and only included single pressure SF6 breakers. A description is given of the scope and objectives of the CIGRE 13.06 Working Group. A brief description is given of some of the highlights from their studies.

  9. Numerical Analysis of the Arc Plasma in a Simplified Low-voltage Circuit Breaker Chamber with Ferromagnetic Materials

    Institute of Scientific and Technical Information of China (English)

    Wu Yi; Rong Mingzhe; Yang Qian; Hu Guangxia

    2005-01-01

    This paper is devoted to the simulation of the arc plasma in a simplified low-voltage circuit breaker chamber. Based on a group of coupled governing equations, a three-dimensional (3-D) arc plasma model is built and solved by a modified commercial code. Firstly, this paper presents a solution of the stationary state of the arc plasma and discusses the distribution of some parameters throughout the chamber. Secondly, with the ferromagnetic materials included,the balance of the stationary state is broken and a transient course is calculated. In light of the simulation results, the temperature distribution sequence, the arc motion and the plasma jet are then described and analyzed in detail.

  10. 大容量发电机出口断路器选择%Circuit Breakers Selection Method for Large-capacity AC High-voltage Generator

    Institute of Scientific and Technical Information of China (English)

    张爽

    2011-01-01

    针对大容量发电机出口断路器的选择问题,依据GB/T 14824-2008、IEEE Std C37.013-1997和IEC 60909-0-2001中的计算方法,并结合发电机出口断路器型式试验报告的有关数据,以某百万千瓦级发电机组为例进行了比较计算,分析计算结果,提出了对发电机出口短路器短路电流开断能力不能采用百分比而应采用绝对值进行校验.%For selecting large-capacity AC high-voltage generator circuit breakers in a large generator system, comparative calculations are conducted for a million kilowatts rated generator following the standards of GB/T 14824-2008, IEEE Std C37.013-1997 and IEC 60909-0-2001. The calculation results and the test reports of generator circuit breakers are analyzed, and a suggestion is hence offered that absolute value of short-circuit current should be used for examining the short-circuit current breaking capacity of an AC high-voltage generator circuit breaker instead of percentage value.

  11. Field Experiments on 10 kV Switching Shunt Capacitor Banks Using Ordinary and Phase-Controlled Vacuum Circuit Breakers

    Directory of Open Access Journals (Sweden)

    Wenxia Sima

    2016-01-01

    Full Text Available During the switching on/off of shunt capacitor banks in substations, vacuum circuit breakers (VCBs are required to switch off or to switch on the capacitive current. Therefore, the VCBs have to be operated under a harsh condition to ensure the reliability of the equipment. This study presents a complete comparison study of ordinary and phase-controlled VCBs on switching 10 kV shunt capacitor banks. An analytical analysis for switching 10 kV shunt capacitor banks is presented on the basis of a reduced circuit with an ungrounded neutral. A phase selection strategy for VCBs to switch 10 kV shunt capacitor banks is proposed. Switching on current waveforms and switching off overvoltage waveforms with, and without, phase selection were measured and discussed by field experiments in a 110 kV substation in Chongqing, China. Results show that the operation of phase-controlled VCBs for 10 kV switching shunt capacitor banks is stable, and phase-controlled VCBs can be used to implement the 10 kV switching on/off shunt capacitor banks to limit the transient overvoltage and overcurrent. The values of overvoltage and inrush current using phase-controlled VCBs are all below those with ordinary VCBs.

  12. Application of Fast Vacuum Circuit Breaker in Electric System%快速真空断路器在电力系统中的应用

    Institute of Scientific and Technical Information of China (English)

    艾绍贵; 马奎; 吴旭涛; 孙丽琼

    2016-01-01

    介绍了涡流驱动型快速真空断路器的原理,分析了目前配网消弧消谐、故障选线及触电防护、电网短路电流限制、串联补偿及变压器直流偏磁抑制等技术的现状和存在的问题。根据快速真空断路器特点,提出了解决相关技术问题的方法,阐述了相关装置的结构、试验及应用情况,并对快速真空断路器在电力系统中的应用进行了展望。%Introduction was made to the principle of eddy current forced fast vacuum circuit breaker. Analysis was made to the technolo-gies used and problems existing including arc and resonance elimination, fault line selection and electric shock protection, grid short-circuit current limitation, series compensation and transformer direct current magnetic bias suppression etc technologies in distribution network at present. According to the characteristic of fast vacuum circuit breaker, the solution method of those problems was proposed. This paper ex-pounded the structure, experiment and application of the relevant device. The further application of the circuit breaker is prospected.

  13. Selection of Circuit Breaker at the Outlet of LV Diesel Generator%低压柴油发电机出口处断路器的选择

    Institute of Scientific and Technical Information of China (English)

    蒋炜栋; 王坚

    2013-01-01

    介绍柴油发电机短路电流的计算方法;计算某柴油发电机的短路电流;利用计算结果选择此柴油发电机出口处断路器。%This paper introduces the calculation method of short circuit current of diesel generator, calculates the short circuit current of the diesel generator, and selects the circuit breaker at the outlet of diesel generator based on the calculation results.

  14. Numerical study of turbulence-influence mechanism on arc characteristics in an air direct current circuit breaker

    Science.gov (United States)

    Wu, Mingliang; Yang, Fei; Rong, Mingzhe; Wu, Yi; Qi, Yang; Cui, Yufei; Liu, Zirui; Guo, Anxiang

    2016-04-01

    This paper focuses on the numerical investigation of arc characteristics in an air direct current circuit breaker (air DCCB). Using magneto-hydrodynamics (MHD) theory, 3D laminar model and turbulence model are constructed and calculated. The standard k-epsilon model is utilized to consider the turbulence effect in the arc chamber of the DCCB. Several important phenomena are found: the arc column in the turbulence-model case is more extensive, moves much more slowly than the counterpart in the laminar-model case, and shows stagnation at the entrance of the chamber, unlike in the laminar-model case. Moreover, the arc voltage in the turbulence-model case is much lower than in the laminar-model case. However, the results in the turbulence-model case show a much better agreement with the results of the breaking experiments under DC condition than in the laminar-model case, which is contradictory to the previous conclusions from the arc researches of both the low-voltage circuit breaker and the sulfur hexafluoride (SF6) nozzle. First, in the previous air-arc research of the low-voltage circuit breaker, it is assumed that the air plasma inside the chamber is in the state of laminar, and the laminar-model application gives quite satisfactory results compared with the experiments, while in this paper, the laminar-model application works badly. Second, the turbulence-model application in the arc research of the SF6-nozzle performs much better and gives higher arc voltage than the laminar-model application does, whereas in this paper, the turbulence-model application predicts lower arc voltage than the laminar-model application does. Based on the analysis of simulation results in detail, the mechanism of the above phenomena is revealed. The transport coefficients are strongly changed by turbulence, which will enhance the arc diffusion and make the arc volume much larger. Consequently, the arc appearance and the distribution of Lorentz force in the turbulence-model case

  15. 带电测量断路器接触电阻方法的研究%Design of Electriifed Measuring Contact Resistance in Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    陈杏灿; 程汉湘; 彭湃; 冼冀

    2015-01-01

    This paper presented a new real-time measuring method for the contact resistance of the operated circuit breakers. A pair of potential transformer worked in parallel to measure indirectly the voltage difference on the two terminals of the circuit breaker, while the currents lfowing through circuit breakers were measured by current transformers. The result of contact resistance could be obtained based on Ohm Law. The analysis shows that this method could not only guarantee the isolation between control system and strong current, but also measure the contact resistance in real time, which would effectively prevent circuit breakers accidents.%提出了一种可对运行中的断路器实时测量其接触电阻的新方法。通过两个电压互感器采集断路器两端对地电压,求得断路器两端的电压差,同时测得流过断路器的电流,根据欧姆定律即可得接触电阻。分析表明,该方法可在保证测量系统与高压隔离的前提下,实时带电测量断路器的接触电阻。对预防断路器的安全事故,保证断路器可靠运行具有重要意义。

  16. 断路器跳位监视与防跳回路的分析与改进%Analysis and Improvement on Open-Position Monitoring and Anti-Pumping Circuit of Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    叶晴炜

    2015-01-01

    某变电站252 kV SF6瓷柱式断路器防跳回路因设计缺陷使断路器跳位监视回路存在寄生回路,导致操作箱对断路器的跳位监视发生错误。分析了防跳回路对跳位监视回路的影响,并对比了550 kV H-GIS断路器出现的类似问题。阐述了成因和解决方法,对防跳回路的设计提出了改进,在跳位监视回路中串联断路器常闭辅助节点和就地防跳继电器的常闭节点,以解决寄生回路对跳位监视的影响。%The anti-pumping circuit of a 252 kV SF6 circuit breaker used in a certain substation existed parasitic circuits in its open-position circuit because of design deficiency, which caused the operation box to make mistakes towards the open-position monitoring of the circuit breaker. This paper analyzed the effect of the anti-pumping circuit on the open-position monitoring circuit, and compared with a similar phe-nomenon that happened to the 550 kV H-GIS circuit breaker. The factor and solution has been explained, and it has also proposed improve-ment towards the design of the anti-pumping circuit. In the open-position monitoring circuit, the normally closed auxiliary nodal point of the circuit breaker was connected in series to the normally closed nodal point in in-site anti-pumping relay of the circuit breaker to remove the effect of parasitic circuits on open-position monitoring.

  17. AUTOMATED ANALYSIS OF BREAKERS

    Directory of Open Access Journals (Sweden)

    E. M. Farhadzade

    2014-01-01

    Full Text Available Breakers relate to Electric Power Systems’ equipment, the reliability of which influence, to a great extend, on reliability of Power Plants. In particular, the breakers determine structural reliability of switchgear circuit of Power Stations and network substations. Failure in short-circuit switching off by breaker with further failure of reservation unit or system of long-distance protection lead quite often to system emergency.The problem of breakers’ reliability improvement and the reduction of maintenance expenses is becoming ever more urgent in conditions of systematic increasing of maintenance cost and repair expenses of oil circuit and air-break circuit breakers. The main direction of this problem solution is the improvement of diagnostic control methods and organization of on-condition maintenance. But this demands to use a great amount of statistic information about nameplate data of breakers and their operating conditions, about their failures, testing and repairing, advanced developments (software of computer technologies and specific automated information system (AIS.The new AIS with AISV logo was developed at the department: “Reliability of power equipment” of AzRDSI of Energy. The main features of AISV are:· to provide the security and data base accuracy;· to carry out systematic control of breakers conformity with operating conditions;· to make the estimation of individual  reliability’s value and characteristics of its changing for given combination of characteristics variety;· to provide personnel, who is responsible for technical maintenance of breakers, not only with information but also with methodological support, including recommendations for the given problem solving  and advanced methods for its realization.

  18. Simulation of the Arc Behavior in Puffer-type High Voltage Circuit Breaker Considering the Influence of Nozzle Ablation

    Institute of Scientific and Technical Information of China (English)

    JIANG Xu; ZHONG Jianying; ZHANG Youpeng; ZHANG Gaochao; LI Xingwen; JIA Shenli

    2013-01-01

    In order to investigate the influence of nozzle ablation to arc,a 2 D axisymmetric magneto-hydro-dynamics arc model is developed to simulate the arc behavior during the whole interruption process in a puffer type high voltage circuit breaker,considering the nozzle ablating and the mixing process of Polytetrafluoroethylene(PTFE) vapor with SF6.The results show that the arc radius firstly increases and then decreases as arc current varies according to its sinusoida waveform.At 3.5 ms after arc initiation the nozzle ablation starts,and 2.5 ms later the current nearly reaches its peak value and nozzle ablation develops intensely.Meanwhile the nozzle is blocked by arc at this time and consequently the vapor concentration in nozzle reaches the highest.Then while the current decreasing and open distance increaseing the vapor concentration gradually decreases.Before current zero the extinction peak of arc voltage occurs.It indicates that the PTFE vapor enhances pressure rise in arc quenching chamber and strengthens the arc blocking effect on nozzle; the arc radius is wider and arc temperature is lower when nozzle ablation is considered.

  19. 直流开断技术的进展与新型直流断路器%Development of Modern DC Switching Technologies and New Type of DC Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    陈德桂

    2014-01-01

    The renaissance of DC system promotes the progress of DC interruption technologies.First of all,this paper introduced the new demands for DC switches according to its application area to be expanded,then the difference between DC and AC interruption characteristics was analyzed,especially,non-stable phenomena to quenching DC arc is shown in the region of small DC current interruption.Based on the above analysis,some new DC interruption technologies and new types of DC circuit breakers were presented,including permanent magnet circuit breaker without polarity;DC circuit breaker derived from AC;gas filled DC circuit breaker;DC circuit breaker with artificial current zero produced by self-excitation oscillation circuit.%提出了直流系统对直流开断的新要求,分析了直流开断与交流分断的区别。同时介绍了几种直流开断新技术与新型直流断路器,包括无极性直流断路器、由交流派生直流断路器、密封充气式直流开关、自励振荡人工零点直流断路器,理清了直流开断技术的进展。

  20. Influence of the gas flow rate on the nonchemical equilibrium N2 arc behavior in a model nozzle circuit breaker

    Science.gov (United States)

    Wu, Yi; Sun, Hao; Tanaka, Yasunori; Tomita, Kentaro; Rong, Mingzhe; Yang, Fei; Uesugi, Yoshihiko; Ishijima, Tatsuo; Wang, Xiaohua; Feng, Ying

    2016-10-01

    The influence of the gas flow rate on the N2 arc behavior was investigated based on a previously established nonchemical equilibrium (non-CE) model. This numerical non-CE model was adopted in the N2 nozzle arc in a model circuit breaker. The arc behaviors of both the arc burning and arc decay phases were obtained at different gas flow rates in both the non-CE and local thermal equilibrium (LTE) model. To better understand the influence of the gas flow rate, in this work we devised the concept of the nonequilibrium parameter. Additionally, the influences of convection, diffusion, and chemical reactions were examined separately to determine which one contributed most to the non-CE behavior. Finally, laser Thomson scattering (LTS) measurements at different gas flow rates were adopted to further demonstrate the validity of the non-CE model. The results of the macroscopic behaviors indicate that the deviations between the non-CE and LTE models during the arc burning phase are much fewer than those during the arc decay phase. By the nonequilibrium parameters, it clearly indicates that with an increase in the gas flow rate, the non-CE effect will be greatly enhanced. During the arc burning phase, this non-CE effect is mainly caused by radial diffusion of the particles. During the arc decay phase, for the charged particles, the chemical reactions had the greatest effect on the time variations of the particle number densities; however, for the neutral particles the time variations of the number densities were mutually influenced by convections, diffusions, and chemical reactions. Finally, the LTS results further demonstrate the validity of the non-CE model at different gas flow rates.

  1. Analysis of Decomposition Products Due to Floating Potential Discharge in SF6 Circuit Breaker%SF6断路器内部悬浮电位放电产生的分解产物分析

    Institute of Scientific and Technical Information of China (English)

    杨韧; 吴水锋; 薛军; 菅永峰; 陈江韩; 孙志恒; 修士新

    2013-01-01

    Abnormal content of SO2 gas was detected in a 126 kV SF6 circuit breaker,which inferred a latent fault in this circuit breaker.Theoretical analysis and disassembling inspection of the circuit breaker indicated that this latent fault was due to floating potential discharge in this circuit breaker.This paper analyses the forming process of floating potential and its influence on the operating characteristics of the circuit breaker.And the generation mechanisms of gaseous and solid decomposition products of SF6 gas under floating potential discharge are discussed.%在某断路器SF6分解产物检测时发现SO2气体体积分数异常,判断该断路器存在潜伏性缺陷.通过理论分析并对断路器进行解体检查,最终判断该断路器的潜伏性缺陷为悬浮电位放电故障.笔者分析了悬浮电位的形成过程及其对断路器的影响,分析了SF6气体在悬浮电位放电下的气体以及固体分解组分的生成机理.

  2. Improvement of energy storage motor control circuit of hydraulic actuator in high-voltage circuit breakers%高压断路器液压操动机构储能电机控制回路改进

    Institute of Scientific and Technical Information of China (English)

    张全民; 赵玉柱

    2011-01-01

    高压断路器液压操动机构的常见故障是储能电机频繁启动。通过合理地设计储能电机的控制回路,减少了液压机构频繁启动的现象。%The fault of the mechanism of High voltage circuit-breaker is motor of storaging power high frequency starup.That rationally design control circuit of hydraulic mechanism reduce the fault that motor of storaging power high frequency starup.

  3. 虚拟样机技术在断路器优化中的应用研究%Application Study of Virtual Prototype Technology in Optimization of Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    于永站; 张金泉; 孙永雷; 陈大江

    2012-01-01

      以 KFW2系列万能式断路器为列,介绍了虚拟样机技术在断路器优化中的应用,利用 ADAMS软件建立断路器虚拟样机模型,对断路器的运动情况进行仿真,模拟了实物样机的真实运动情况,得到断路器各部件在分离、试验、连接位置时的行程数据,并给出了关键部件在试验和连接位置时的行程范围。通过分析结果表明,虚拟样机技术对低压断路器的优化提供了新的技术途径%  Taking KFW2 series open-construction circuit breaker as an example, this paper introduced the application of virtual prototype technology in circuit-breaker optimization. ADAMS software was used to build up a circuit-breaker virtual prototype model to carry out simulation for movement conditions of circuit breakers. The real movement conditions of actual prototype was simulated to get the travel data of circuit-breaker each component at separating, test, contact positions and travel ranges of key components at test and contact positions were given. The results of analysis show that virtual prototype technology has provided new technology path for low-voltage circuit-breaker optimization.

  4. Three-Dimensional Simulation of Plasma Deformation During Contact Opening in a Circuit Breaker, Including the Analysis of Kink Instability and Sausage Instability

    Institute of Scientific and Technical Information of China (English)

    Vahid ABBASI; Ahmad GHOLAMI; Kaveh NIAYESH

    2012-01-01

    A three-dimensional (3-D) transient model has been developed to investigate plasma deformation driven by a magnetic field and its influence on arc stability in a circuit breaker. The 3-D distribution of electric current density is obtained from a current continuity equation along with the generalized Ohm's law; while the magnetic field induced by the current flowing through the arc column is calculated by the magnetic vector potential equation. When gas interacts with an arc column, fundamental factors, such as Ampere's law, Ohm's law, the turbulence model, transport equations of mass, momentum and energy of plasma flow, have to be coupled for aria- lyzing the phenomenon. The coupled interactions between arc and plasma flow are described in the fl'amework of time-dependent magnetohydrodynamic (MHD) equations in conjunction with a K-~ turbulence model. Simulations have been focused on sausage and kink instabilities in plasma (these phenomena are related tO pinch effects and electromagnetic fields). The 3-D sjm- ulation reveals the relation between plasma deformation and instability phenomena, which affect arc stability during circuit breaker operation. Plasma deformation is the consequence of coupled interactions between the electromagnetic force and plasma flow described in simulations.

  5. 南阳特高压断路器失灵保护的研究%Study on Nanyang substation of UHV circuit breaker failure protection

    Institute of Scientific and Technical Information of China (English)

    姜自强; 刘建勇

    2015-01-01

    晋东南-南阳-荆门特高压示范工程的正式投运标识着特高压电网的建设已进入快速发展阶段,但是特高压二次系统时间常数的增大使得CT拖尾现象变得不可忽视。一方面,对特高压断路器 CT电流互感器的选型提出了新的问题,只选择TPY次级则会进一步恶化CT拖尾现象,选择P次级则增加成本。另一方面,CT拖尾对断路器失灵保护的正确动作造成了负面的影响。针对该情况,对特高压3/2断路器接线方式下断路器的失灵保护进行了研究,并提出一种针对性的改进方案。通过对比分析、仿真实验以及数模实验结果,证明该修改方案是切实可行的。既能有效地解决特高压断路器 CT电流互感器的选型问题,也能有效地解决 CT拖尾对失灵保护的危害问题。%The formal commissioning Jindongnan-Nanyang-Jingmen UHV demonstration project identifies that the construction of special high-voltage power grid has entered a rapid development stage, but the increase of UHV two system time constant makes the CT become tailing phenomenon can not be ignored. On the one hand, it puts forward a new problem for the selection of UHV circuit breaker CT current transformer, namely selecting only the TPY secondary will deteriorate further CT tailing phenomenon and selecting the P secondary will increase the cost. On the other hand, CT trailing influences breaker failure protection, making it unable to right action. In view of this situation, it studies the failure protection under the wiring mode of 3/2 breaker in UHV and proposes an improved scheme. The contrast analysis, simulation and RTDS experimental results prove that the modified scheme is feasible, which can both effectively solve the problems of the selection of UHV circuit breaker CT current transformer and CT tailing hazard failure protection.

  6. SF6断路器中润滑脂过量引起的分解产物分析%Analysis of Decomposition Products by Grease Overdose in SF6 Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    杨韧; 吴水锋; 汪金星; 菅永峰; 陈江韩; 孙志恒; 修士新

    2013-01-01

    An abnormal level of CO gas was detected in a 126 kV SF6 circuit breaker when it was beingtested.According to the analysis,potential fault has occurred in this circuit breaker.After chemical analysis and experimental research on the source of the CO gas,we disintegrated the circuit breaker in order to check it.Finally we come to conclusion that the fault was caused by the excessive scribbling of lubricating grease.The paper analyses the lubricating grease's influence on the operating characteristics of circuit breaker and the decomposition products of SF6.%对SF6电气设备检测时发现某126 kV断路器CO气体组分体积分数异常,根据分析,该断路器存在潜伏性故障.通过化学分析以及实验研究对可能产生CO的来源进行了分析,并对断路器进行解体检查,最终判断该断路器潜伏性故障产生的原因为润滑脂过量.笔者通过化学反应机理分析了润滑脂涂敷过量对断路器运行特性及SF6气体分解组分的影响.

  7. Interruption of a dry-type transformer in no-load by a vacuum circuit-breaker

    Science.gov (United States)

    Vandenheuvel, W. M. C.; Daalder, J. E.; Boone, M. J. M.; Wilmes, L. A. H.

    1983-08-01

    Overvoltages generated during interruption of a dry type delta-star connected transformer in no load by a vacuum breaker were studied. During interruption of inrush current 37% of the phase-to-ground overvoltages were 5 pu, and 6% 7 pu. Comparison of experimental and theoretical results using Boyle's model shows no discrepancy for inrush currents and clean overvoltages from the steady-state interruption. Overvoltages due to repetitive reignitions (not covered by Boyle's model) are higher than the calculated values during steady-state switching.

  8. Simulation of Arc Rotation and Its Effects on Pressure of Expansion Volume in an Auto-Expansion SF6 Circuit Breaker

    Science.gov (United States)

    Zhang, Junmin; Chi, Chengbin; Guan, Yonggang; Liu, Weidong; Wu, Junhui

    2016-03-01

    A 3D Magnetohydrodynamics (MHD) arc model in conjunction with an arc movement model is applied to simulate the arc rotation as well as to solve its effect on the pressure in an auto-expansion circuit breaker. The rotation of the arc driven by an external electromagnetic force is simulated in the case with 200 kA of the short circuit current and 16 ms of arc duration. The arc rotating process and the speed of arc rotation have been obtained in the simulation. A comparison of the pressure in the expansion volume with and without an external magnetic field has been carried out based on the calculation results of two cases. The results of the simulation reveal that the arc rotation, which causes more energy exchange between the arc and its surrounding gas, can evidently bring about the pressurization in the expansion volume, which would contribute to more effective arc quenching at current zero and further reducing operation power. supported by National Natural Science Foundation of China (Nos. 51177005 and 51477004)

  9. 750 kV断路器现场交流耐压试验系统研究与应用%Site AC Voltage Withstand Test System Study and Application of 750 kV Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    温定筠; 乔立凤; 江峰; 王成生; 孙亚明; 吕景顺

    2013-01-01

      介绍了750 kV断路器现场交流耐压试验的标准和时序,分析了基于串联谐振原理的试验方法及试验系统中各设备的具体参数。在此基础上配置出成套的750 kV断路器现场交流耐压试验系统,通过实例成功完成了750 kV断路器主回路及断口的交流耐压试验。%  Introduction was made to the standard and time sequence of site AC voltage withstand test of 750 kV circuit breakers. Analysis was made to the test methods based on serial resonance principle and actual parameters of different equipment in test system. On the basis of this, the site AC voltage withstand test system of a set of 750 kV circuit breakers was disposed. The actual example shows that the AC voltage withstand test for the main circuit and breaking outlet of 750 kV circuit breakers could be completed successfully.

  10. Control Strategy and Experimental Study of Hybrid HVDC Circuit Breaker%混合式高压直流断路器的控制策略与实验研究

    Institute of Scientific and Technical Information of China (English)

    杜翼; 江道灼; 陈可; 王玉芬; 尹瑞; 张弛

    2014-01-01

    现有的高压直流断路器能够在几十ms内断开电路,但对于高压直流输电系统,远不能达到要求。基于半导体的高压直流断路器能克服动作速度上的问题,但需要大量电力电子开关器件串并联,有很高的技术难度,同时会产生大量损耗。为了克服上述缺点,采用一种混合式高压直流断路器的拓扑结构。首先介绍了断路器开通和关断的原理,接着提出一种故障预处理的控制策略,在故障发生时提前进行换流,从而缩短故障发生后线路开断的时间;最后利用PSCAD进行建模仿真,制作了单元样机进行降压实验。仿真和实验结果证明:在系统发生短路的情况下,混合式直流断路器能够快速开断短路电流,还可以在直流线路分断后为直流线路及负载中储存的能量提供释放回路。%Existing HVDC circuit breakers are capable of interrupting HVDC currents within several tens of milliseconds, but this is too slow to fulfill the requirements of a reliable HVDC grid.HVDC breakers based on semiconductors can easily overcome the limitations of operating speed,but need large number of the series (parallel ) connection of electronic switching devices;at the same time, it requires high technology and generates a lot of loss. To overcome these shortcomings,a topology of hybrid HVDC circuit breaker was introduced.Firstly,this paper described the principle of hybrid HVDC circuit breaker;then a control strategy of fault pretreatment was also proposed,that was the pre-action of the converter when fault occurred,in order to improve the breaking speed of the hybrid circuit breaker;at last the modeling and simulation were carried out on the hybrid HVDC circuit breaker by PSCAD,and unit prototype was made for the step-down experiments.The simulation and experimental results prove that:when a short circuit occurs,the hybrid HVDC circuit breaker can quickly break the short-circuit current

  11. 继电器、断路器、交流接触器在100 kW发射机中的应用%Relays, Circuit Breakers, AC Contactors used in 100 kW Transmitters

    Institute of Scientific and Technical Information of China (English)

    范学东

    2015-01-01

    DF100 kW transmitter, using a lot of relays, circuit breakers, AC contactor control switch as a transmitter. Detailed summary of all relays, circuit breakers, AC contactors whole transmitter, and various switches for a detailed explanation for reference.%DF100 kW发射机中采用了很多继电器、断路器、交流接触器作为发射机中的控制开关。详细总结了整部发射机的所有继电器、断路器、交流接触器,并对各种开关进行了详细的讲解,以供参考。

  12. Monitoring of circuit breakers and detection of rupture cables through the IEDs - intelligent electronic devices; Monitoracao de disjuntor e deteccao de cabos rompidos atraves de IEDs - dispositivos eletronicos inteligentes

    Energy Technology Data Exchange (ETDEWEB)

    Lellys, Denys [Areva T and D Brasil, Sao Paulo, SP (Brazil); Cruz, Jorge; Esteves, Eduardo; Lisboa, Luiz Afonso [Centrais Eletricas do Para (CELPA), Belem, PA (Brazil); Rolim, Joaquim C.; Garrido, Roberto; Silveira, Giordane [Companhia Energetica do Ceara (COELCE), Fortaleza, CE (Brazil)

    2009-04-15

    The advances on digital techniques allowed the inclusion into the modern protection relays, monitoring auxiliary functions of the state of circuit breakers, and the detection of cable rupture, which can reduce the maintenance costs, and increase the operational safety. This article describes in detail those resources, not yet well explored, presenting from the the theoretical base to the practical application and the expected technical and economical results.

  13. Analysis on dielectric loss characteristic of ionic defect on circuit-breaker parallel capacitor%断路器并联电容器离子性缺陷介损特性分析

    Institute of Scientific and Technical Information of China (English)

    马飞越; 郝金鹏; 田禄

    2014-01-01

    By the high voltage dielectric loss test on the type of JWF150-1500 and JWF150-0.0015GHW circuit-breaker parallel capacitors,discoveres that with voltage increase the dielectric loss value of some circuit-breaker parallel capacitors obvious change,exists ionic defect. Through the data and theoretical analysis,explains the reason of the dielectric loss change with voltage increase and the effects of ionic defects on circuit-breaker parallel capacitor,suggests the effective solution.The result shows that routine test and test before operation under 10 kV voltage,the tan δhas large measure deviation value, and with voltage change the high voltage dielectric loss decreased obviously,can judge the circuit-breaker parallel capacitor have ionic defect.%对JWF150-1500型和JWF150-0.0015GHW型断路器并联电容器进行高压介质损耗试验,发现部分断路器并联电容器随电压升高介损值变化明显,存在离子性缺陷。通过数据和理论分析,解释了断路器并联电容器介质损耗随电压变化的原因及离子性缺陷对断路器并联电容器影响,并提出有效解决措施。结果表明:例行试验与投运前试验时10 kV下tanδ测量值偏差较大,且高压介损随电压变化下降明显的断路器并联电容器,可认定存在离子性缺陷。

  14. TAN/LOFT 13. 8 KV, 2. 4 KV, and 480 V relay and circuit breaker coordination study

    Energy Technology Data Exchange (ETDEWEB)

    Burnett, J.E.

    1977-10-28

    Present overcurrent relay settings are presented and evaluated for adequacy in terms of the updated short circuit analysis. Recommendations are made for new relay and trip device settings to improve coordination. Switchgear ratings are examined against available short circuit currents, and recommendations are made where applicable. Vital MCC-A and B are examined in detail to provide maximum continuity of service for every fault contingency. A recommendation is made to improve the reliability of these buses.

  15. Path Tracking Control of Vacuum Circuit Breaker%真空断路器循迹控制

    Institute of Scientific and Technical Information of China (English)

    秦涛涛; 董恩源; 陈宇硕; 段雄英; 邹积岩

    2014-01-01

    采用带自调整函数的模糊算法,能够使断路器永磁机构按给定曲线动作,保证断路器的合闸时间稳定,从而提高选相操作的精度。通过该算法可实时纠正断路器永磁机构的运动位移偏差,在电容电压、环境温度等外界因素发生变化时,使机构仍按给定曲线动作。通过开关特性测试仪和DSP2812硬件控制系统,得到标准位移曲线及控制算法中的基本参量值,并在 Matlab 中建立了考虑续流过程的真空断路器闭环控制系统,给出了电容电压变化的仿真结果,验证了上述控制方法的可行性。此外,针对单相配永磁机构真空断路器,进行大量的合闸实验。实验结果表明:在上述外界因素变化时,该控制方法能将断路器合闸时间稳定在±0.5 ms之内。%A fuzzy algorithm with self-turning function was proposed in this paper to make Permanent Magnetic Actuator (PMA) move along with the given displacement curve. Then the closing time of PMA is stable and the precision of phase-selection operation is improved. The deviation of displacement, caused by the variation of capacitor voltage and ambient temperature, can be corrected by the algorithm in real time. So PMA can still move along with the given displacement curve. The standard displacement curve and the basic parameters were obtained by the high-voltage switch testing equipment and hardware system DSP2812 respectively. Meanwhile, a closed-loop system, considering free-wheeling process of coil, was established in the software Matlab to verify the feasibility of the algorithm when the voltage of capacitor varied. In addition, a large number of tracing experiments have been done on the breakers and the results proved that closing time of breaker can be stabilized within±0.5ms under the condition of changing capacitor voltage and ambient temperature.

  16. Mechanical Fault Diagnosis of High Voltage Circuit Breakers Based on Wavelet Time-Frequency Entropy and One-Class Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Nantian Huang

    2015-12-01

    Full Text Available Mechanical faults of high voltage circuit breakers (HVCBs are one of the most important factors that affect the reliability of power system operation. Because of the limitation of a lack of samples of each fault type; some fault conditions can be recognized as a normal condition. The fault diagnosis results of HVCBs seriously affect the operation reliability of the entire power system. In order to improve the fault diagnosis accuracy of HVCBs; a method for mechanical fault diagnosis of HVCBs based on wavelet time-frequency entropy (WTFE and one-class support vector machine (OCSVM is proposed. In this method; the S-transform (ST is proposed to analyze the energy time-frequency distribution of HVCBs’ vibration signals. Then; WTFE is selected as the feature vector that reflects the information characteristics of vibration signals in the time and frequency domains. OCSVM is used for judging whether a mechanical fault of HVCBs has occurred or not. In order to improve the fault detection accuracy; a particle swarm optimization (PSO algorithm is employed to optimize the parameters of OCSVM; including the window width of the kernel function and error limit. If the mechanical fault is confirmed; a support vector machine (SVM-based classifier will be used to recognize the fault type. The experiments carried on a real SF6 HVCB demonstrated the improved effectiveness of the new approach.

  17. Advantages of the synthetic technique for the conduction of short circuit tests to breakers; Ventajas de la tecnica sintetica para realizar pruebas de corto circuito a interruptores

    Energy Technology Data Exchange (ETDEWEB)

    Sibilski, Henry [Instituto Electrotecnico de Varsovia, Varsovia (Poland); Ochoa Vivanco, Ruben [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    In this article the operational principle of the synthetic test is described; specifically of the current injection circuit in parallel. Its utilization in the research and development of new breaker models and its wide possibilities regarding its testing characteristics is outlined. Likewise the different tests that can be performed by means of the synthetic technique are described. Finally the importance of the synthetic tests is outlined for the development of own technology in the area of interruption equipment and emphasis is made that in industrialized countries this technique is of common practice. [Espanol] En este articulo se describe el principio de operacion de la prueba sintetica; especificamente del circuito de inyeccion de corriente en paralelo. Se destaca su utilizacion en la investigacion y desarrollo de nuevos modelos de interruptores y sus amplias posibilidades en cuanto a caracteristicas de prueba. Asimismo, se describen las diferentes pruebas que pueden realizarse mediante la tecnica sintetica. Por ultimo, se destaca la importancia de las pruebas sinteticas para el desarrollo de tecnologia propia en el area de equipos de interrupcion, y se hace notar que en paises desarrollados, esta tecnica es practica comun.

  18. Calculation of radiative properties of SF6-C2F4 thermal plasmas—application to radiative transfer in high-voltage circuit breakers modelling

    Science.gov (United States)

    Jan, C.; Cressault, Y.; Gleizes, A.; Bousoltane, K.

    2014-01-01

    Radiative transfer is a key point for accurate simulations of arcs in high voltage circuit breakers where the plasma is mainly composed, at high current, of a mixture of SF6 and PTFE vapours (C2F4 and decomposition products). Assuming local thermodynamic equilibrium, we have built a database of absorption coefficients over almost 300 000 spectral points, for a pressure range between 1 and 100 bar, temperatures from 300 to 50 000 K, and proportions from pure SF6 to pure C2F4. From these data, we have calculated the mean absorption coefficients (MAC) by considering several definitions of the mean coefficient and several spectral ranges or intervals. The choice between the various definitions was operated using a one dimensional radiative transfer model with imposed temperature profiles. The results showed that a combination of a normal average over the molecular continuum at low temperature, with a mixed definition of Planck average at high temperature gives the most accurate results. The optimization of the number of intervals for the definition of the MAC database was performed and showed that the accuracy on the radiative flux and on the divergence of the flux depends on the temperature profile. A good compromise is obtained with five or seven intervals.

  19. Gas breakers for tokamak OHMIC-heating duty

    International Nuclear Information System (INIS)

    The current interrupting capacity of air blast and SF6 breakers is reviewed for application in tokamak ohmic-heating circuits. Particular attention is paid to generator breakers for their large current interrupting capacity and suitability for ohmic-heating circuits

  20. A New Method of Rising the Intensity of Self-Restoring Insulation in Circuit Breaker%一种提高断路器自恢复绝缘强度的新方法

    Institute of Scientific and Technical Information of China (English)

    刘明光; 颜怀梁

    1999-01-01

    The physical process when a circuit breaker cutsout the arc ofshort-circuit current in a power system is analysed ,and that the neutral point in a system grounds through a special nonlinear grounding resistor is presented in this papepr.The method can restrict the speed of shortcircuit current which flows through zero value.Therefore it raises the intensity of self-restoring insulation and enhances the ability of cutting out short-circuit current in circuit breaker.The calculating result is found to be close to the test one.%当电力系统断路器切断短路电弧时,通过物理分析,提出在系统中性点接入一个特殊的非线性接地电阻的方法.这个方法可以限制短路电流过零点的增长速度,因而可以提高自恢复绝缘强度,增强断路器切断短路电流的能力,计算结果与测试一致.

  1. "Hyperglutamatergic cortico-striato-thalamo-cortical circuit" breaker drugs alleviate tics in a transgenic circuit model of Tourette׳s syndrome.

    Science.gov (United States)

    Nordstrom, Eric J; Bittner, Katie C; McGrath, Michael J; Parks, Clinton R; Burton, Frank H

    2015-12-10

    The brain circuits underlying tics in Tourette׳s syndrome (TS) are unknown but thought to involve cortico/amygdalo-striato-thalamo-cortical (CSTC) loop hyperactivity. We previously engineered a transgenic mouse "circuit model" of TS by expressing an artificial neuropotentiating transgene (encoding the cAMP-elevating, intracellular A1 subunit of cholera toxin) within a small population of dopamine D1 receptor-expressing somatosensory cortical and limbic neurons that hyperactivate cortico/amygdalostriatal glutamatergic output circuits thought to be hyperactive in TS and comorbid obsessive-compulsive (OC) disorders. As in TS, these D1CT-7 ("Ticcy") transgenic mice׳s tics were alleviated by the TS drugs clonidine and dopamine D2 receptor antagonists; and their chronic glutamate-excited striatal motor output was unbalanced toward hyperactivity of the motoric direct pathway and inactivity of the cataleptic indirect pathway. Here we have examined whether these mice׳s tics are countered by drugs that "break" sequential elements of their hyperactive cortical/amygdalar glutamatergic and efferent striatal circuit: anti-serotonoceptive and anti-noradrenoceptive corticostriatal glutamate output blockers (the serotonin 5-HT2a,c receptor antagonist ritanserin and the NE alpha-1 receptor antagonist prazosin); agmatinergic striatothalamic GABA output blockers (the presynaptic agmatine/imidazoline I1 receptor agonist moxonidine); and nigrostriatal dopamine output blockers (the presynaptic D2 receptor agonist bromocriptine). Each drug class alleviates tics in the Ticcy mice, suggesting a hyperglutamatergic CSTC "tic circuit" could exist in TS wherein cortical/amygdalar pyramidal projection neurons׳ glutamatergic overexcitation of both striatal output neurons and nigrostriatal dopaminergic modulatory neurons unbalances their circuit integration to excite striatothalamic output and create tics, and illuminating new TS drug strategies.

  2. Design of Mechanical Characteristics Test Instrument for Vacuum Circuit Breaker Base on Linux%基于Linux的真空断路器机械特性测试仪的设计

    Institute of Scientific and Technical Information of China (English)

    胡敏

    2011-01-01

    真空断路器的可靠性,主要依赖于其机械特性的可靠性,而这需要有相应的测试设备来对其状态进行检测,便于工作人员对其进行维护.真空断路器机械特性测试仪是以嵌入式Linux为平台构建的嵌入式操作系统,运用Qt/E编写了界面美观、人机交互性能良好的操作控制图形用户界面程序,运用MySQL数据库编写相应的程序模块实现检测结果的存储、查询和传输,达到高精度、高性能、操作简便实现真空断路器机械特性参数测试的目的.%The reliability of vacuum circuit breaker mainly depends on Its mechanical characteristic, which needs relevant test equipment to give a test so as to maintain the vacuum circuit breaker. Embedded operating system is developed based on the embedded Linux. In this system, Qt/E is used to edit graphical user interface programs. Based on MySQL database, we edit relevant program module to store,retrieve and transfer testing results,in order to attain the goal of testing mechanical characteristic parameter of vacuum circuit breaker with high precision, high performance and easy operation.

  3. 基于IGBT串联技术的混合式高压直流断路器方案%A Hybrid High Voltage DC Circuit Breaker Design Plan With Series-Connected IGBTs

    Institute of Scientific and Technical Information of China (English)

    药韬; 温家良; 李金元; 陈中圆

    2015-01-01

    大力发展可再生能源将是解决我国能源资源分布不平衡,电力供需紧张,实现经济可持续发展的必然选择.综合常规直流输电技术和柔性直流输电技术,建立高压直流电网将是解决大规模可再生能源并网问题的有效手段.回顾高压直流断路器的发展历程,介绍当前最新的研究成果,阐明现阶段高压直流断路器将要面临的挑战,分析比较不同类型高压直流断路器的典型拓扑结构、工作原理和优缺点.在此基础上提出一种基于绝缘栅双极型晶体管(insulated gate bipolar transistor,IGBT)串联技术的混合式高压直流断路器方案,详细介绍其拓扑结构、特点和工作原理,基于舟山5端直流工程在PSCAD/EMTDC软件中搭建仿真模型验证了其可行性.%Vigorously developing renewable energy will be an inevitable choice to solve the unbalanced distribution of energy resources, ease the tension between electricity supply and demand, and achieve sustainable economic development in China. To integrate conventional DC transmission technology and flexible DC transmission technology, establishing HVDC grid would be an effective means to solve the problem of large scale grid-connected of renewable energy. In this paper the history of HVDC circuit breaker is reviewed, the latest research results are introduced, the current challenges for HVDC circuit breaker are illustrated. Also the typical topological structure, working principle, advantages and shortcomings of different types of HVDC circuit breaker are analyzed and compared. Based on this, a new hybrid HVDC circuit breaker design with series-connected insulated gate bipolar transistors (IGBTs) is presented, and the topology characteristics and its working principles are introduced in details. Zhoushan five-terminal DC transmission system is modeled and simulated in the PSCAD/EMTDC software to verify its feasibility.

  4. 220 kV变电站GIS断路器短路典型事故分析%Analysis on Typical GIS Breaker Short-circuit Fault in 220 kV Substation

    Institute of Scientific and Technical Information of China (English)

    李晓刚

    2014-01-01

    介绍了某220 kV变电站气体绝缘金属封闭开关设备(gas insulated metal enclose switchgear,GIS)断路器短路事故经过。通过对220 kVGIS短路事故后的故障录波、气体成分、断路器解体及出厂原始数据的综合分析,认为在出厂时的雷电冲击试验中的击穿、放电造成的断路器极间绝缘筒的缺陷是事故发生的主要原因。并通过事故过程的还原从另一角度验证了事故原因分析的正确性,并提出了相应的建议,同时为类似 GIS 故障的处理分析提供借鉴与参考。%This paper introduces one GIS breaker short-circuit accident in some 220 kV substation.By comprehensively analy-zing fault recording,gas components,breaker disintegration and factory original data after the short-circuit fault,the main reason for the accident was considered to be defect of breaker interelectrode insulating cylinder caused by breakdown and discharge in factory lightning impulse test.Meanwhile,by review on the accident,correctness of accident reason analysis was verified from another angle and relevant suggestions were proposed for providing references on similar GIS fault handling a-nalysis.

  5. Vacuum Dielectric Recovery Characteristics of a Novel Current Limiting Circuit Breaker Base on Artificial Current Zero%新型强迫换流型限流断路器真空介质强度的恢复特性

    Institute of Scientific and Technical Information of China (English)

    江壮贤; 庄劲武; 王晨; 武瑾; 刘路辉

    2012-01-01

    In order to maintain the reliability of the opening operation of a new vacuum DC current limiting circuit breaker in cutting off short circuit current, the vacuum dielectric recovery after current zero was investigated. An equivalent experiment was designed and set up. Dynamic vacuum dielectric recovery characteristic of the circuit breaker during opening of the vacuum contacts was achieved from experiments results and theoretical deduction. Researching results show that the breakdown voltage of the vacuum interrupter can be improved with less arcing energy and higher contact moving speed; and with the increasing of arcing time the breakdown voltage reduces at first and increases later. These results can be used in the designing of the new vacuum DC circuit breaker.%为了保证新型强迫换流型真空直流限流断路器关断短路电流的可靠性,对该型断路器分断过程的真空介质恢复特性进行研究。设计了与断路器关断过程等效的介质恢复试验方案,通过等效试验结果和理论推演公式的拟合,得到了新型强迫换流型限流断路器真空灭弧室触头打开过程的动态介质强度恢复规律。研究结果表明:减小燃弧能量、提高触头运动速度可提高真空灭弧室介质的临界击穿电压;综合考虑燃弧时间与燃弧能量及触头开距的关系,随着燃弧时间的增加,真空灭弧室临界击穿电压先减小后增大。所得介质恢复规律可以作为新型断路器优化设计的参考依据。

  6. Review on Out-Of-Phase Making and Breaking Test Method of High-Voltage Circuit Breaker%高压断路器失步开合试验方法的评述

    Institute of Scientific and Technical Information of China (English)

    吴盛刚; 张建新; 赵建沛; 王鹏飞; 周跃刚

    2013-01-01

    Description was made to the multiple test circuits and the test conditions of high-voltage circuit breakers in carrying out out-of-phase making and breaking test and comparison was made to their advantages and disadvantages. According to the actual test conditions in test station, this paper selected transformer double-circuit which is convenient to carry out and parallel voltage injec-tion circuit and calculated parameters of 126 kV level test loop. Simulation was carried out for the relevant transient recovery voltage waveforms. The result is in conformity with the expected requirements, so it can be implemented.%阐述了高压断路器进行失步开合试验的多种试验线路及其试验条件,并比较了各自的优缺点。根据试验站的具体设备条件,选取了便于实施的变压器双联电路和并联电压引入回路,并计算了126 kV级试验回路的参数,对相应的瞬态恢复电压TRV波形进行了仿真,其结果符合预期要求,故可以实施。

  7. 6 kV high-voltage vacuum circuit breaker operating mechanism optimization way%6 kV 高压真空断路器操动机构优化方式总结

    Institute of Scientific and Technical Information of China (English)

    许江鑫; 李卫利

    2015-01-01

    company way introduced in detail in the high voltage power supply system of 6 kv vacuum circuit breaker operating mechanism in the process of action cannot be points in a short time, feed motion,making points,closing electromagnet charged burned for a long time,and affect the normal operation of the process equipment,especially in the process need to stop immediately when the equipment is in failure,will cause the circuit breaker operating mechanism transformation,in order to control points,closing electromagnet burned down,and thus can ensure the stable operation of power supply system,to ensure the production system and stable operation for a long period of time.%详细介绍了公司在6 kV 高压供电系统中真空断路器操动机构在动作过程中出现不能在较短时间内进行分、合闸动作,从而使分、合闸电磁铁长时间带电烧毁,影响现场工艺设备的正常运行,特别是在工艺设备出现故障需要立即停车时,如果在分闸过程中出现电磁铁烧毁,将造成断路器无法正常停下来,从而造成事故扩大化。如何进行断路器操动机构优化改造,以此来控制分、合闸电磁铁烧毁问题,从而能够保证供电系统和生产系统的稳定运行。

  8. Rectifier cabinet static breaker

    Science.gov (United States)

    Costantino, Jr, Roger A.; Gliebe, Ronald J.

    1992-09-01

    A rectifier cabinet static breaker replaces a blocking diode pair with an SCR and the installation of a power transistor in parallel with the latch contactor to commutate the SCR to the off state. The SCR serves as a static breaker with fast turnoff capability providing an alternative way of achieving reactor scram in addition to performing the function of the replaced blocking diodes. The control circuitry for the rectifier cabinet static breaker includes on-line test capability and an LED indicator light to denote successful test completion. Current limit circuitry provides high-speed protection in the event of overload.

  9. Application of CF4 Detection to Insulation Fault Diagnosis for Gas Interrupter of Circuit Breaker%CF4检测在气体灭弧室绝缘故障诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    印华; 唐世宇; 徐韬; 姚强; 何宁

    2012-01-01

    SF6气体分解产物检测在电气设备故障分析中的应用比较广泛,而由于新气中含有一定量的CF4,所以分析重点集中于H2S、SO2、SOF2、SO2F2、HF几种特征气体.笔者将SF6气体分解产物检测技术应用于一起500 kV气体断路器的故障诊断,气体检测结果和解体检查表明断路器喷口发生非正常的电孤烧蚀,在经历较长一段时间后,仅体现在SF6气体中CF4体积分数的显著增加.从而表明,对于SF6气体绝缘电气设备应该定期进行检测气体分解物,对CF4体积分数的增加也应引起足够的重视,注重数据的横向和纵向的分析比较.%Detection technology of SF6 decomposition products has been wildly used in the fault analysis of SF6 insulated power equipments. The detection is focused on the characteristic gases such as H2S,SO2, SOF2,SO2F2 and HF because the new SF6 gas contains CF4. In this paper, the detection technology of SF6 decomposition products is used in a fault diagnosis of 500 kV SF6 circuit breaker. The detection results of SF6 decomposition products show that after a long time only the volume fraction of CF4 in SF6 increases significantly as the nozzle of circuit breaker was abnormally eroded by the arc. Therefore, the SF6 decomposition products ought to be detected periodically, including the volume fraction of CF4. It's also necessary to compare the detection results with the former ones, and with those of other equipments.

  10. Differences Analysis Between New and Old Standard IEC 61008-1 for Residual Current Operated Circuit-Breakers%剩余电流动作断路器IEC 61008-1新旧标准差异分析

    Institute of Scientific and Technical Information of China (English)

    何秀明

    2013-01-01

    The article introduced the revision situation of IEC 61008-1: 2012 (edition 3.1) for the residual current operated circuit-breakers (RCCBs) without integral overcurrent protection for household and similar uses, comparing with IEC 61008-1:1996 (edition 2.0) and IEC 61008-1:1996 am1(2002) and analyzing the differences about the scope, terms and definition, characteristics, marking, standard working conditions, construction and operation requirement, tests and annexes, so as to provide references for the corresponding technical personnel.%  介绍了家用和类似用途的不带过电流保护的剩余电流动作断路器(RCCB)IEC 61008-1:2012(3.1版)的修订情况,并与IEC 61008-1:1996(2.0版)及IEC 61008-1:1996 am1(2002)进行了比较,分析了新旧标准在范围、术语和定语、特性、标志、标准工作条件、结构和操作的要求、试验及附录等方面的差异,供相关技术人员进行参考.

  11. NUMERICAL SIMULATION OF THREE DIMENSINAL ELECTRIC FIELD NEAR THE BREAK OF THE SF6 CIRCUIT BREAKER%SF6断路器灭弧室内三维电场数值模拟

    Institute of Scientific and Technical Information of China (English)

    曹云东; 王尔智; 刘晓明

    2001-01-01

    运用有限元法FEM对罐式SF6断路器断口附近三维电场进行了数值计算,以计算机辅助绘图为支撑,完成了SF6断路器三维电场的数值模拟。在三维电场数学模型的建立中考虑了屏蔽罩和并联电容器组的存在; 对断路器不同三维剖面的等电位线分布及电场分布情况进行了分析; 并将计算结果进行三维图形可视化处理及显示。%In this paper, three-dimensional electric field of SF6 circuit breaker has been calculated by applying the finite element method based on the computer aided graphic, the 3-D electric field numerical simulations are achieved. In the mathematic models of the three dimensional electric field,the shield and the parallel capacitors are considered; the potential and the electric field distributions of the different three-dimensional profiles are analyzed and figured.

  12. Application in Parameters Testing of Moulded Case Circuit Breaker Based on KingView Database%基于组态王数据库在塑壳断路器参数测试中的应用

    Institute of Scientific and Technical Information of China (English)

    吴学忠; 李飞; 匡红兵

    2015-01-01

    介绍了组态王SQL数据库的特点和访问功能,分析了塑壳断路器参数测试系统组成和PLC数据与组态王变量关联方式,利用组态王SQL及变量组态技术组态和编制命令程序实现对测试数据库的操作。运行结果表明,该应用有效提高了产品测试的质量控制和数据分析能力。%Introduction was made to the features and access functions of KingView structured query language (SQL) database. This paper analyzed the associated mode between the composition of moulded case circuit breaker (MCCB) parameters testing system and the programmable logic controller (PLC) database, as well as the KingView variables. The KingView SQL and variables configuration technology, together with the programming commands were used to realize the operation on testing database. The operational results show that this application effectively improves the quality control and data analysis ability of product testing.

  13. Study on Electromagnetic Operating Mechanism Holding Force Compensation Method of Circuit Breaker%断路器电磁操动机构合闸保持力补偿方法的研究

    Institute of Scientific and Technical Information of China (English)

    车焕

    2016-01-01

    新型电力机车主断路器用电磁操动机构处于合闸位置时,其保持力由一组保持线圈励磁实现。由于机车上电源电压波动大且机车工作环境温度变化大,此保持力的变化范围非常大。为了稳定合闸时的保持力,保证电磁操动机构稳定工作,提出采用直流斩波的方法对合闸保持力进行补偿。%When the new type electromagnetic operating mechanism using for electric locomotive main circuit breaker is in the closing position, its keeping force is provided by a group of holding coil . Because of power supply voltage on the locomotive and environment temperature of the locomotive all changes greatly.In order to stabilize the keeping force, guarantee the stability of electromagnetic operating mechanism, a dc chopper method is proposed to compensate keeping force.

  14. 船用交流中压断路器开断性能相关参数分析%Analysis of Parameters for Breaking Performance of Marine Medium Voltage AC Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    杨青

    2013-01-01

    According to the characteristics of marine medium voltage power system,the parameters closely related to the breaking performance of medium voltage AC circuit breaker were analyzed.It is shown that the key performance parameters in land standards,such as rated breaking current,making current,power frequency recovery voltage,transient recovery voltage,electrical life and so on,basically meet the marine requirements after conversion. But there are also some individual parameters need to be studied further to decide.%根据船舶中压电力系统的特点,对中压断路器开断性能密切相关的参数进行了分析。结果表明,陆用标准中额定短路开断电流和关合电流、工频恢复电压和瞬态恢复电压、电寿命等参数经过换算、折算,基本上符合船用要求,个别参数是否合适有待进一步研究。

  15. 广东地区变电站出线断路器侵入波过电压实时数字仿真分析%Realtime Digital Simulation of Lightning Surge Intrusion on Outlet Circuit Breakers of Substations in Guangdong Region

    Institute of Scientific and Technical Information of China (English)

    彭向阳; 姚森敬; 郭婷; 周文俊

    2012-01-01

    General situation of substation outlet circuit breaker faults caused by lightning surge intrusion occurred in Guangdong region before the installation of outlet arrester is described, and it is clarified that the lightning surge intrusion protection for outlet circuit breakers during its reclosure must be reinforced, i.e., outlet arresters must be installed in front of outlet circuit breakers. Utilizing real-time" digital simulator (RTDS), the overvoltage caused by lightning surge intrusion during the reclosure of outlet circuit breaker is simulated, and the effect of enhancing insulation level of transmission line and the protection result of adding outlet arresters are evaluated as well. Simulation results show that after outlet arrester is installed, although the insulation level of transmission line is strengthened considerably, dangerous lightning surge intrusion will not appear on outlet circuit breaker, thus the operating condition of lightning protection for substation can be effectively improved.%介绍广东地区变电站未安装出线避雷器前雷电侵入波事故概况,明确了必须加强出线断路器重合闸期间的侵入波保护,即应安装出线断路器前置避雷器。利用实时数字仿真器(real.timedigitalsimulator,RTDS)分析变电站出线断路器开断期间雷电侵入波过电压,并对加强线路绝缘的影响以及出线避雷器的保护效果进行评估。计算结果表明:变电站装设出线避雷器后,即使大幅提高输电线路绝缘水平,也不会在出线断路器产生危险的雷电侵入波过电压,能有效地改善变电站防雷运行工况。

  16. Improvement of failure protection for high voltage side circuit breaker of 220 kV transformer%220kV变压器高压侧断路器失灵保护的改进

    Institute of Scientific and Technical Information of China (English)

    郑春生

    2016-01-01

    Failure protection of Shengli Oilfield 220 kV substation main transformer circuit breaker, its typical configuration cannot effectively isolate the fault point, in some atypical failure,the main transformer for a long time by the impact of short-circuit current,seriously affect the power system stability and safety. The failure protection action nodes and mother difference protection action nodes and the corresponding non electric starter relay series, when startup failure protection, the corresponding node closed, start relay, to direct trip-ping of main transformer with three side of the switch. Using this improved scheme, 3 of Shengli Oilfield 220 kV substation main transformer failure protection has been improved, reduces the possibility of 220 kV Main Transformer be impact by the fault current, guarantee the safe and stable operation of power grids.%胜利油田220 kV变电站主变断路器失灵保护中的典型配置不能有效隔离故障点,在一些非典型故障中,会使主变长时间受到短路电流冲击,严重影响电力系统稳定性和安全性.为此,将失灵保护动作节点和母差保护动作节点与相应的非电量启动继电器串联,当失灵保护启动时,相应节点闭合,启动继电器,进而直接跳开主变三侧开关.应用此改进方案,对胜利油田3座220 kV变电站的主变失灵保护进行了完善,降低了220 kV主变压器受到故障电流冲击的可能性,保障了电网安全、稳定运行.

  17. Analysis on Connection Error in Current Transformer Secondary Circuit of 500 kV Tank Circuit Breaker with Countermeasures%500kV罐式断路器电流互感器二次回路接线错误的分析及对策

    Institute of Scientific and Technical Information of China (English)

    杨忠礼; 牛元泰; 吴征; 任平力

    2012-01-01

    介绍了一起因500 kV罐式断路器电流互感器二次回路接线错误而产生的重大隐患,当500 kV罐式断路器本体发生故障时,由于线路保护与母线保护使用的电流互感器绕组接线未实现交叉,使得两者的保护范围没有交叉,存在保护死区,从而会导致主保护拒动.通过对全站500 kV系统保护用电流互感器绕组接线的检查和分析,发现造成保护死区主要是设计和安装两方面的原因,针对这两方面原因,提出了加强规范管理,在设计施工阶段加强一二次施工人员的配合以及施工、验收和日常维护时注重对该部分的检查等一系列具体的反事故措施,为今后罐式断路器继电保护用电流互感器绕组的设计、安装调试以及现场验收及维护提供了借鉴.%A hidden danger owing to connection error in the current transformer secondary circuit of 500 kV tank circuit breaker is introduced. When the 500 kV tank circuit breaker went wrong, the main protections did not trip to clear the fault because current transformer windings for respective line protection and bus protection had not been cross-connected hence two protection ranges did not overlapped and main protection did not work. The protection dead zone is found to be due to some problems in both design and installation of the current transformer through checking and analyzing the current transformer winding. Consequently, some countermeasures' for avoiding the protection dead zone are suggested, such as strengthening cooperation between primary and secondary builders during design and installation stage, and paying more attention to examinations in construction, acceptance and daily maintenance stages.

  18. Analysis on the Standard Conformance of Thermal Circuit Breaker of Heat-pump Water Heater and Air-conditioner%关于热泵热水器和空调热断路器结构标准符合性浅析

    Institute of Scientific and Technical Information of China (English)

    马洁丹; 肖凯佳

    2015-01-01

    This paper analyzes the standard conformance of the construction of thermal circuit breaker in air-condi-tioner and heat pump and some designs according to the standards of IEC 60335 series. Besides, it provides responding suggestions to the designers.%本文根据标准IEC 60335系列,对带电辅热的空调及热泵的热断路器及部分设计方案进行标准符合性分析,给出相应的意见,以供设计人员参考.

  19. Study on process of marking two-dimensional codes on air circuit breakers by UV laser%紫外激光标记空气开关的工艺研究

    Institute of Scientific and Technical Information of China (English)

    吴煜文; 郭亮; 张庆茂; 吕启涛; 张超

    2012-01-01

    激光器的打标速度、频率、填充间隔、电流、离焦量等工艺参数直接影响空气开关的打标效果.实验根据5因素4水平正交表L16(45)改变激光工艺参数,利用分光测色计和二维码扫描器对激光标记分别进行色差和读码率的测量,通过正交分析法和极差法研究激光工艺参数对打标效果的影响.研究表明:色差与读码率的数据趋于正比关系,并且存在一个阈值色差;当激光参数的速度为1 000 mm/s、频率为20~30 kHz、填充间隔为0.04 mm、电流为28A、离焦量为-1 mm时,在空气开关上打标出点密度合适、色差对比度高、易于读取的二维码.%The quality of two-dimensional codes on air circuit breakers depends on laser parameters such as scanning speed, Q frequency, line spacing, electric current and defocusing distance. The experiment changed laser parameters according to the orthogonal table L16(4S). Color difference was measured by a spectrophotometer and code success ratio was tested by a bar code scanner. Orthogonal analysis and range analysis were carried out to study the influence of laser parameters on marking effect. The experiment shows that, there is a threshold color difference and the linear relationship between color difference and code success ratio is good. Perfect two-dimensional codes are obtained with optimum laser parameters, which are 1 000 mm/s scanning speed, 20-30 kHz Q frequency, 0.04 mm line spacing, 28 A electric current and -1 mm defocusing distance.

  20. Review of the Numerical Prediction Method for the Interruption Capability of SF6 Circuit Breakers%SF6断路器开断能力数值预测方法研究综述

    Institute of Scientific and Technical Information of China (English)

    牟京卫; 郭瑾; 李兴文; 陈冰; 辛昭昭; 游一民

    2012-01-01

    Numerical prediction methods both for the thermal interruption capability and the dielectric recovery capability of SF6 gas circuit breaker (GCB) are reviewed in the paper. The arc conductance 200 ns (G200) before current zero is a key parameter of the thermal interruption capability of the GCB. The magneto-hydro-dynamics (MHD) model is applied during the arcing process and the Mayr model is 'adopted near current zero to evaluate the Gxo- Then the arc time constant and the arc power loss coefficient could be obtained. To evaluate the dielectric recovery capability of GCB, the reduced electric field strength Ec has to be calculated everywhere in the interrupter after current zero. The reduced critical electric filed strength £a has to be computed as well. The probability of the dielectric breakdown after current zero can be judged by the comparison of the £a and Ec. It has to be indicated that the proposed numerical prediction methods are still need to be verified by further experimental efforts.%综述了SF6断路器极限开断能力以及介质开断能力的数值预测方法的最新研究进展.电流过零前200 ns的电弧电导(G200)是判断断路器热开断能力的一个重要参数,为计算G200,对电弧特性进行模拟,在燃弧阶段采用磁流体动力学模型,而在接近电流零区采用Mayr模型,从而建立相应的电路模型来确定电弧时间常数和电弧功率损耗系数等参数,以分析高压断路器的热开断能力.为判断电击穿能力,需要根据电弧过零时灭弧室内的每一点的压力和温度值,确定对应点的临界击穿场强分布Ec,同时计算在暂态恢复电压作用下灭弧室内的电场分布Ea,然后通过比较灭弧室内各处Ea和Ec的值,就可以判断出灭弧室内不同区域电击穿几率的大小.

  1. 基于MATLAB仿真的缓冲器对断路器分闸特性影响研究%Simulation Study on the Influence of Multi-orifice Hydraulic Buffer on Opening Characteristics of High Voltage Circuit Breaker Based on MATLAB

    Institute of Scientific and Technical Information of China (English)

    余明星; 赵伟涛

    2015-01-01

    为研究用于弹簧操动机构中的排孔式液压缓冲器结构参数对高压断路器分闸特性的影响,文中以排孔式缓冲器工作原理为基础建立了缓冲过程的数学模型,应用MATLAB对数学模型进行仿真求解。仿真所得曲线与试验曲线相吻合,证明了仿真的准确性,并依此为依据,仿真得到缓冲器在不同阻尼孔直径、不同阻尼孔位置、不同活塞与缸体配合间隙以及不同分闸弹簧刚度下对断路器分闸特性的影响,该研究为设计出满足断路器分合特性的缓冲器提供了理论指导。%In order to investigate the influence of structure parameters of multi-orifice hydraulic buffer which used in the spring operating mechanism of high voltage circuit breaker to the opening operation , in this paper, a mathematical model of cushioning process based on buffer working principle is established. Then simulate and solve such mathematical model by MATLAB. First of all , to verify the simulation accuracy, the simulation and experimental curves are compared and analyzed. Then on this basis, through numerical simulation, it is found that the diameter and the spacing interval of damped orifice, the clearance between piston and cylinder block, and the stiffness of trip spring would influence the opening operation of circuit breaker. This study provides the theoretical guidance for designing and optimizing the performance of hydraulic buffer.

  2. 用于高压断路器金短时间控制的辅助开关延时特性研究%Research on the Delay Time of Auxiliary Switch for the Close-open Time Controlling in High-voltage Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    刘坚钢; 金立军

    2012-01-01

    高压断路器重合闸操作的金属短接时间(金短时间),是保证断路器“C-O”操作第二“分”开断能力的重要参数.现有高压SF6断路器的金属短接时间通常不能满足标准推荐的50 ms的指标.高压断路器的分合闸指令是由其操动机构配置的辅助开关发出的,因而辅助开关是金短时间控制的理想而可靠的机构.笔者分析了高压断路器辅助开关的结构,在理论力学和系统动力学的基础上,对辅助开关操动特性进行了研究,研究成果通过实验验证.%The close-open time of extra-high voltage circuit breaker reclosing is an important parameter to ensure the second contact separation breaking capacity of "close-open" operation. The close-open time of high voltage SFg breakers is less than time 50 ms which is recommend by the standard. The close and open commands are issued by auxiliary switch equipped by the operating mechanism, so the auxiliary switch is an ideal and reliable mechanism to control the close-open time. Based on theoretical mechanics and system dynamics, the structure of the auxiliary switch is analysis, the operation characteristics of auxiliary switch is studied, and the research results are verified by experiments.

  3. A study on Main Breaker for Quench Protection of HT—7U Toroidal Superconducting Tokammak

    Institute of Scientific and Technical Information of China (English)

    许留伟; 刘小宁

    2002-01-01

    This paper proposes a quench protection project of HT-7U toroidal superconducting tokamak through a forced commutation analysis of DC circuit breaker(DCCB) paralleling fuse.Based on the requirement of quench protection.Amin parameters are selected.Experimental results demonstrate the validity of this proposed project.

  4. A Study on Main Breaker for Quench Protection of HT-7U Toroidal Superconducting Tokamak

    Institute of Scientific and Technical Information of China (English)

    许留伟; 刘小宁

    2002-01-01

    This paper proposes a quench protection project of HT-7U toroidal superconducting tokamak through a forced commutation analysis of DC circuit breaker (DCCB) paralleling fuse.Based on the requirement of quench protection, main parameters are selected. Experimental results demonstrate the validity of this proposed project.

  5. 330 MW火电机组发变组出口断路器跳闸原因分析%Trip cause analysis for outlet circuit breaker trip of generator-transformer unit in 330 MW coal-fired power plant

    Institute of Scientific and Technical Information of China (English)

    余民

    2015-01-01

    针对一起330 MW火电机组发变组出口断路器在无任何保护动作情况下的跳闸故障,采用逐步排查法,通过现场模拟实验,找出了故障的原因,提出有效解决办法并制定了防范措施.应用结果表明:改进措施消除了机组存在的安全隐患,确保了机组的长周期安全运行.%Aiming at an accident of generator-transformer unit outlet circuit breaker trip without any protection device act in 330 MW coal-fired power plant,using gradual elimination method and field simulation test,finds out the causes of the trip,puts forward effective solution and preventive measures. The application result shows that the improved measures eliminate the hidden safety trouble,guarantee long periodic safe operation of the 330 MW coal-fired power generation unit.

  6. Experience with the Alpine Breaker Line Support

    Energy Technology Data Exchange (ETDEWEB)

    Habnicht, H.; Halbmayer, C.

    1989-01-01

    The Alpine Breaker Line Support is new, mechanised support equipment for stabilising the caving edge during depillaring operations. A short discussion is presented of some panel geometry variations used, and of performance data achieved. 5 figs.

  7. 30 CFR 75.900-2 - Approved circuit schemes.

    Science.gov (United States)

    2010-07-01

    ... undervoltage protection for each circuit that receives power from that transformer. (c) One circuit breaker may... regarded as providing the necessary protection to the circuit required by § 75.900: (a) Ground check relays may be used for undervoltage protection if the relay coils are designed to trip the circuit...

  8. A threshold for the Maker-Breaker clique game

    NARCIS (Netherlands)

    Muller, Tobias; Stojakovic, Milos

    2014-01-01

    We study the Maker-Breaker k-clique game played on the edge set of the random graph G(n, p). In this game, two players, Maker and Breaker, alternately claim unclaimed edges of G(n, p), until all the edges are claimed. Maker wins if he claims all the edges of a k-clique; Breaker wins otherwise. We de

  9. Magnetic selfinsulation of transmission lines with a nanosecond circuit breaker

    International Nuclear Information System (INIS)

    The paper deals with application of plasma erosion switches for peaking power of pulse generators. Basic characteristics of magnetic selfinsulation waves which propagate in vacuum transmission line after operation of plasma erosion switch. It is shown that consideration of electron flow results in the decrease of voltage pulse amplitude by 20% as compared to the vacuum case. The influence of finiteness of switch time on pulse magnitude is considered

  10. 46 CFR 111.54-1 - Circuit breakers.

    Science.gov (United States)

    2010-10-01

    ...; see 46 CFR 110.10-1); (ii) ANSI/IEEE C37.27 (incorporated by reference; see 46 CFR 110.10-1); or (iii... C37.04, IEEE C37.010, and ANSI/IEEE C37.12 (all three standards incorporated by reference; see 46 CFR... provision of Article 240 of NFPA NEC 2002 or IEC 92-202 (both incorporated by reference; see 46 CFR...

  11. Video auditing techniques for breaker reject

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, B.M.; Corke, P.I.; O`Brien, G.D.; Waugh, J.M. [CSIRO (Australia). Division of Minerals

    1998-12-31

    Rotary breakers are used by many Australian coal mines to reduce the topsize of run of mine (ROM) coal to a size that can be handled by the processing plant. Coal that does not break to the designated topsize therefore passes out with the rock as breaker rejects. The degree of coal loss can be assessed manually by stop belt auditing of the reject belt, but this method is impractical for long-term monitoring of breaker rejects and breaker performance. Case studies of several open cut coal mines in the Bowen Basin of Central Queensland were made to determine the extent of the problem. The results indicated instances where significant losses did occur, but it was not possible to make an accurate estimate of the total value of the losses. This paper covers work undertaken to develop new auditing techniques for qualitative, quantitative and continuous monitoring of reject belt material which uses relatively low-cost equipment and mature technology. Initial work has concentrated on developing video surveillance techniques suitable for the range of environmental conditions typically encountered in the field. Multi-media methods are being developed for qualitative data presentation, and image analysis techniques are being investigated to extract basic quantitative information from video sequences, such as particle size and shape. Future work includes development of automatic methods using machine vision for 100% on-line inspection. The main attraction of the methodology being adopted is the potential to easily adapt the techniques to diagnostic and control functions. In situations where significant losses occur, this approach could open up many possibilities for reducing coal rejection or allowing its recovery from the rejects stream to improve productivity. 12 refs., 4 figs., 1 tab.

  12. Automatic Speed Breaker on Time Demand Using Embedded Systems

    Directory of Open Access Journals (Sweden)

    Sanchit Vashistha

    2012-11-01

    Full Text Available The concept of this research work is to have an automatic speed breaker on time demand according to the requirements. Means when there is no need of the speed breaker on the road, it disappears from the road and the road becomes flat and when there is a need then the breaker comes on the road from ground and it starts its working of slowing speed of the vehicles. In implementation of this concept, we use an iron made hemi-cylindrical speed breaker which is capable of rotating itself using control circuitry of embedded systems. So when needed, it comes on the road by rotating itself from flat position and when not needed, it rotates itself again and gets flat and combines with flat road. In the system, real time clock is used to mention the required time for having the speed breaker on road. When time gets started, breaker comes on the road and remains until the countdown gets zero. In the Embedded system’s clock any time and date can be stored on which the speed breaker is required on the road. So this type of speed breaker is useful before any building for which the time is specified for coming in the building and going out from it e.g. schools, any organization etc.

  13. Anti-rebound Cushion Device for Hydraulic Breaker

    Institute of Scientific and Technical Information of China (English)

    Zhao Hongqiang

    2005-01-01

    This paper analyzes the phenomenon of rebound impact and its negative influence on the present hydraulic breaker. To get over its shortcomings, a new anti-rebound cushion device has been designed to prevent the phenomenon of rebound impact. A hydraulic cushion is used to absorb the rebound impact energy, which can be released for the next stroke of the hydraulic breaker. Thus, there is little loss of energy, and the efficiency of the impact system can be increased by 5 %. The absorption effect of the hydraulic anti-rebound cushion increases the service life of breaker components by up to twice as long as in the current breaker. A dynamic model and a motion equation of the anti-rebound cushion device are presented, and the optimum frequency and damping ratio are obtained, providing optimum design parameters for the anti-rebound cushion device.

  14. LARGE EDDY SIMULATION FOR PLUNGING BREAKER WAVE

    Institute of Scientific and Technical Information of China (English)

    Bai Yu-chuan; Wang Zhao-yin

    2003-01-01

    As wave propagates into shallow water, the shoaling effect leads to increase of wave height, and at a certain position, the wave will be breaking. The breaking wave is powerful agents for generating turbulence, which plays an important role in most of the fluid dynamical processes in the surf zone, so a proper numerical model for describing the turbulent effect is needed urgently. A numerical model is set up to simulate the wave breaking process, which consists of a free surface model using the surface marker method and the vertical two-dimensional model that solves the flow equations. The turbulence is described by Large Eddy Simulation (LES) method where the larger turbulent features are simulated by solving the flow equations, and the small-scale turbulence that is represented by a sub-grid model. A dynamic eddy viscosity sub-grid scale stress model has been used for the present simulation. The large eddy simulation model, which we presented in this paper, can be used to study the propagation of a solitary wave in constant water depth and the shoaling of a non-breaking solitary wave on a beach. To track free-surface movements, The TUMMAC method is employed. By applying the model to wave breaking problem in the surf zone, we found that these model results compared very well with experimental data. In addition, this model is able to reproduce the complicated flow phenomena, especially the plunging breaker.

  15. A Full Hydro- and Morphodynamic Description of Breaker Bar Development

    DEFF Research Database (Denmark)

    Jacobsen, Niels Gjøl

    The present thesis considers a coupled modelling approach for hydro- and morphodynamics in the surf zone, which is based on a solution to the Reynolds Averaged Navier-Stokes (RANS) equations with a Volume of Fluid (VOF) closure for the surf tracking. The basis for the numerical approach is the su......The present thesis considers a coupled modelling approach for hydro- and morphodynamics in the surf zone, which is based on a solution to the Reynolds Averaged Navier-Stokes (RANS) equations with a Volume of Fluid (VOF) closure for the surf tracking. The basis for the numerical approach...... stress on the crest of the breaker bar, and its migration speed. Additionally, a net onshore current over a breaker bar is considered, where this current mimics the presence of a horizontal circulation cell. The development of the breaker bar is described for different values of the net onshore current...

  16. Fracturing Fluid (Guar Polymer Gel Degradation Study by using Oxidative and Enzyme Breaker

    Directory of Open Access Journals (Sweden)

    Aung Kyaw

    2012-06-01

    Full Text Available Oxidative and enzyme breakers are used in this research project with the main objective to study on the degradation pattern of fracturing fluid (i.e., guar polymer gel as a function of time, temperature and breaker concentration itself. The fracturing fluid used in hydraulic fracturing or frac pack contain a chemical breakers to reduce the viscosity of the fluid intermingled with the proppant. Chemical breakers reduce viscosity of the guar polymer by cleaving the polymer into small-molecular-weight fragments. The reduction of viscosity will facilitate the flow-back of residual polymer providing rapid recovery of polymer from proppant pack. Ineffective breakers or misapplication of breakers can result in screen-outs or flow-back of viscous fluids both of which can significantly decrease the well productivity. Breaker activity of low to medium temperature range oxidative and enzyme breaker systems was evaluated. ViCon NF an oxidative breaker (Halliburton product and GBW 12- CD an enzyme breaker (BJ Services product were used in this research project with the main objective to study on the degradation pattern of fracturing fluid (guar polymer gel as a function of (time, temperature and breaker concentration itself. This study provides focuses on the way to mix the fracturing fluid, compositions of the fracturing fluid and how to conduct the crosslink and break test. Crosslink test indicate the optimum cross-linker concentration to produce good crosslink gel and the break test gave the characteristic of the gel during degradation process and also the break time. Besides relying on the laboratory experiment, information obtained from research on SPE and US Pattern papers were used to make a comparison study on oxidative and enzyme breakers properties. Degradation pattern observed from the break test showed that reduction in gel viscosity depends on time, temperature and breaker concentration. Observations from experiment also revealed that small

  17. Causes Analysis, Treatment and Prevention of Remote Switch Refused Action and Tripping Coil Burnout in 110kV Circuit Breaker%110 kV断路器远控分闸开关拒动跳闸线圈烧毁故障原因分析及处理防范

    Institute of Scientific and Technical Information of China (English)

    毛艳东

    2015-01-01

    Through introducing the refused action in breaking the 110kV 161QF remote switch in Dahua hydropower station as well as theoretically analyzing and investigating the reasons of the refused action and the tripping coil burnout, it is found that there is tripping coil burnout risk in the control circuit due to the design defect of switch op-erating mechanism. To eliminate it, some correction measures are presented and brought into operation after passed through on-site inspection.%通过介绍大化水电厂一起远控分闸110 kV 161QF开关过程中出现分闸失灵、开关拒动故障,综合排查故障原因,对跳闸线圈烧毁原因进行详细分析,并通过理论分析, 最后发现开关操作机构设计上存在的缺陷,因操作机构存在的缺陷导致控制回路存在严重隐患,提出整改防范措施,并通过现场检验后投入运行无问题,排除了跳闸线圈烧毁隐患.

  18. Structure design of and experimental research on a two-stage laval foam breaker for foam fluid recycling.

    Science.gov (United States)

    Wang, Jin-song; Cao, Pin-lu; Yin, Kun

    2015-07-01

    Environmental, economical and efficient antifoaming technology is the basis for achievement of foam drilling fluid recycling. The present study designed a novel two-stage laval mechanical foam breaker that primarily uses vacuum generated by Coanda effect and Laval principle to break foam. Numerical simulation results showed that the value and distribution of negative pressure of two-stage laval foam breaker were larger than that of the normal foam breaker. Experimental results showed that foam-breaking efficiency of two-stage laval foam breaker was higher than that of normal foam breaker, when gas-to-liquid ratio and liquid flow rate changed. The foam-breaking efficiency of normal foam breaker decreased rapidly with increasing foam stability, whereas the two-stage laval foam breaker remained unchanged. Foam base fluid would be recycled using two-stage laval foam breaker, which would reduce the foam drilling cost sharply and waste disposals that adverse by affect the environment. PMID:26387358

  19. The wave vane - A device to measure the breaker angle

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Nayak, B.U.; Anand, N.M.

    (1993) 173-181 173 Elsevier Science Publishers B.V., Amsterdam 00036-1 Technical note The wave vane a device to measure the breaker angle P. Chandramohan, B.U. Nayak and N.M. Anand National Institute of Oceanography, Goa 403 004, India (Received... of a wave direction recording instrument, a simple device called the wave vane as described here has been developed to measure the breaking wave angle. The changes in the horizontal component of the orbital velocity under a progressive wave govern...

  20. 断路器结构参数对GIS中特快速暂态过电压波形的影响%Effect of Breaker Structural Parameters on Very Fast-fronted Transient Overvoltage Waveform in GIS

    Institute of Scientific and Technical Information of China (English)

    邵冲; 杨钰; 刘卫东; 王赞基

    2011-01-01

    550 kV及以上电压等级的气体绝缘变电站(GIS)系统中一般采用双断口断路器,并装有均压电容.本文着重分析断路器均压电容、空载母线、接地开关状态等对GIS系统中特快速暂态过电压(VFTO)波形的影响.首先建立了考虑断路器结构的简化GIS分析模型,推导了系统中节点电压的频域解析解答,然后分析了断路器结构参数和接地开关状态对VFTO的影响.结果表明,随着断路器均压电容、对地电容变大以及断路器到隔离开关母线长度的增加,系统中VFTO主要频率变小,但各频率分量的幅值在不同节点处有不同的变化规律;空载母线末端VFTO幅值呈减小趋势,上升沿变平缓,变压器线圈处幅值变化比较小,上升沿陡度变化不大,但上升时间增大;接地开关断开时,断路器断口间电压较小,但断口对地可能产生过电压;接地开关闭合时,断口间和断口对地可能出现谐振过电压,在设计时应予以避免.%The double-fracture circuit-breaker with two grading capacitors is used in gas insulated substation (GIS) at 550kV and above voltage levels. This article focuses on the effect of some parameters of circuit-breaker on very fast-fronted transient overvoltage (VFTO) waveform in GIS, such as the shunt capacitance of circuit breakers, floating bus, grounding switch status and so on. First, a simplified GIS model considering the circuit breaker struc ture was established. The analytical solution in frequency domain of node voltage was derived out from this model. Then, the effects of these parameters were analyzed. The results showed that when the capacitances of shunt capaci tors or the capacitance to ground or the length of bus between circuit-breaker and disconnector increased, the main frequency of VFTO decreased, but the amplitude of each frequency at different nods had different variations, indica ting that the amplitude of VFTO at the end of the no load bus decreased, the rising

  1. The Impact of a Deep-Water Plunging Breaker

    CERN Document Server

    Ikeda, Christine; Brucker, Kyle A; Drazen, David A; Dommermuth, Douglas G; Fu, Thomas; Fullerton, Anne M; Duncan, James H

    2014-01-01

    The impact of a plunging breaking wave (wavelength approximately 1.3m) on a rigidly mounted rigid cube structure (dimension 0.31m) that is partially submerged is explored through experiments and numerical calculations. The experiments are carried out in a wave tank and the breaker is generated with a mechanical wave maker using a dispersive focusing technique. The water-surface profile upstream of the front face of the cube and in its vertical centerplane is measured using a cinematic laser-induced fluorescence technique. The three-dimensional flow in the wave tank is simulated directly using the Numerical Flow Analysis (NFA) code. The experiments and the calculations are used to explore the details of the wave-impact process and, in particular, the formation of the high-speed vertical jet that is found on the front face of the cube under some impact conditions.

  2. Every Speed Breaker Is A Source Of Power

    Directory of Open Access Journals (Sweden)

    N. N. Ghuge,

    2014-03-01

    Full Text Available Electricity in India, is a big problem which is faced by people who reside in the country. Electricity is the form of energy, Electricity is a basic part of nature and it is one of our most widely used forms of energy. We get electricity, which is a secondary energy source, from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. Before electricity generation began slightly over 100 years ago, we use kerosene lamps, and rooms were warmed by wood-burning or coal burning stoves. Direct current (DC electricity had been used in arc lights for outdoor lighting. In the late-1800s, Nikola Tesla pioneered the generation, transmission, and use of alternating current (AC electricity, which can be transmitted over much greater distances than direct current. Generating electricity by speed breakers is innovative and useful concept. R

  3. Numerical modeling of post current-zero dielectric breakdown in a low voltage circuit breaker

    Science.gov (United States)

    Thenkarai Narayanan, Venkat raman

    Oral delivery of macromolecular therapeutics has remained a challenge. Various factors govern principles of oral absorption, including solubility, tissue permeability, stability and dynamics of the gastrointestinal environment. Developing a macromolecular drug carrier for poorly bioavailable drugs is highly desirable. Dendritic polymers are attractive drug delivery vehicles because of their multifunctional surface groups, globular conformation, branched architecture, low poly dispersity and hydrophilic nature. They also offer traditional benefits of macromolecular systems such as extended plasma residence time and reduced systemic toxicity. Developing a poly(amido amine) (PAMAM) dendrimer-based oral drug delivery vehicle is the long-term goal of this research. PAMAM dendrimers can offer advantages in terms of improving solubility and permeability that can ultimately enhance oral absorption of poorly bioavailable drugs. In this dissertation, first the safety and maximum tolerated dose of six different PAMAM dendrimers was studied after oral and systemic administration. Surface charge of these dendrimers significantly influenced their toxicity profile in vivo with cationic systems proving to be more toxic than anionic systems. The inherent permeability of native anionic dendrimers was then evaluated in a mouse model to assess their potential in oral drug delivery. Results suggested that anionic G6.5 dendrimers exhibited appreciable bioavailability with partial degradation observed under in vivo conditions. Subsequently, camptothecin, a model drug used for the treatment of colorectal carcinoma, was attached to PAMAM dendrimers. Antitumor activity revealed that these conjugates were effective in inhibiting growth of cancer cells in vitro. Preliminary efficacy studies conducted in xenograft tumor models also indicated that dendrimer-drug conjugates have potential for oral chemotherapy. Further detailed in vivo studies are needed to demonstrate the utility of PAMAM-drug conjugates for effective and safe delivery of chemotherapeutics by the oral route.

  4. Analysis of Fault Arc in High-Speed Switch Applied in Hybrid Circuit Breaker

    Science.gov (United States)

    Wu, Yifei; Ren, Zhigang; Feng, Ying; Li, Mei; Zhang, Hantian

    2016-03-01

    The behavior of fault arc in a high-speed switch (HSS) has been studied theoretically and experimentally. A simplified HSS setup is designed to support this work. A two-dimensional arc model is developed to analyze the characteristics of fault arc based on magnetic-hydrodynamic (MHD) theory. The advantage of such a model is that the thermal transfer coefficient can be determined by depending on the numerical method alone. The influence of net emission coefficients (NEC) radiation model and P1 model on fault arc is analyzed in detail. Results show that NEC model predicts more radiation energy and less pressure rise without the re-absorption effect considered. As a consequence, P1 model is more suitable to calculate the pressure rise caused by fault arc. Finally, the pressure rise during longer arcing time for different arc currents is predicted. supported by National Key Basic Research Program of China (973 Program) (No. 2015CB251001), National Natural Science Foundation of China (Nos. 51221005, 51177124, 51377128, 51323012), the Science and Technology Project Funds of the Grid State Corporation SGSNKYOOKJJS1501564 and Shaanxi Province Natural Science Foundation of China (No. 2013JM-7010)

  5. Consideration of using 3G cellular network to monitor ABB’s remote circuit breakers

    OpenAIRE

    Afolabi, Ibrahim

    2013-01-01

    Increase in the energy demand for domestic purposes as well as in the manufactur-ing industries has led to a rapid and proportional increase in the electrical energy production today. In meeting this huge electric consumption and demand, proper network and supply of electric power has to be in place from the electric energy generation stations to the final user i.e. the consumers at home, in offices and heavy manufacturing industries. Achieving this goal without mincing safety and securit...

  6. Study of DC Circuit Breaker of H2-N2 Mixture Gas for High Voltage

    Science.gov (United States)

    Shiba, Yuji; Morishita, Yukinaga; Kaneko, Shuhei; Okabe, Shigemitsu; Mizoguchi, Hitoshi; Yanabu, Satoru

    Global warming caused by CO2 etc. is a field where the concern is very high. Especially, automobile emissions are problem for it. Therefore, the hybrid car is widely development and used recently. Hybrid car used electric power and gasoline. So, the car reduces CO2. Hybrid car has engine and motor. To rotate the motor, hybrid car has battery. This battery is large capacity. Therefore, the relay should interrupt high DC current for the switch of the motor and the engine. So, hybrid car used hydrogen gas filling relay We studied interruption test for the research of a basic characteristic of hydrogen gas. DC current has not current zero point. So, it is necessary to make the current zero by high arc voltage and forcible current zero point. The loss coefficient and arc voltage of hydrogen is high. Therefore, we studied interruption test for used high arc voltage. We studied interruption test and dielectric breakdown test of air, pure Hydrogen, and Hydrogen- nitrogen mixture gas. As a result, we realized H2-N2(80%-20%) is the best gas.

  7. Large Eddy Simulation for Plunge Breaker and Sediment Suspension

    Institute of Scientific and Technical Information of China (English)

    BAI Yuchuan(白玉川); C.O.NG

    2002-01-01

    Breaking waves are a powerful agent for generating turbulence that plays an important role in many fluid dynamicalprocesses, particularly in the mixing of materials. Breaking waves can dislodge sediment and throw it into suspension,which will then be carried by wave-induced steady current and tidal flow. In order to investigate sediment suspension bybreaking waves, a numerical model based on large-eddy-simulation (LES) is developed. This numerical model can beused to simulate wave breaking and sediment suspension. The model consists of a free-surface model using the surfacemarker method combined with a two-dimensional model that solves the flow equations. The turbulence and the turbulentdiffusion are described by a large-eddy-simulation (LES) method where the large turbulence features are simulated bysolving the flow equations, and a subgrid model represents the small-scale turbulence that is not resolved by the flowmodel. A dynamic eddy viscosity subgrid scale stress model has been used for the present simulation. By applying thismodel to Stokes' wave breaking problem in the surf zone, we find that the model results agree very well with experimentaldata. By use of this model to simulation of the breaking process of a periodic wave, it can be found that the model canreproduce the complicated flow phenomena, especially the plunging breaker. It reflects the dynamic structures of roller orvortex in the plunging breaker, and when the wave breaks, many strong vortex structures will be produced in the innersurf zone where the concentration of suspended sediment can thereby become relatively high.

  8. The ice-breaker effect: singing mediates fast social bonding.

    Science.gov (United States)

    Pearce, Eiluned; Launay, Jacques; Dunbar, Robin I M

    2015-10-01

    It has been proposed that singing evolved to facilitate social cohesion. However, it remains unclear whether bonding arises out of properties intrinsic to singing or whether any social engagement can have a similar effect. Furthermore, previous research has used one-off singing sessions without exploring the emergence of social bonding over time. In this semi-naturalistic study, we followed newly formed singing and non-singing (crafts or creative writing) adult education classes over seven months. Participants rated their closeness to their group and their affect, and were given a proxy measure of endorphin release, before and after their class, at three timepoints (months 1, 3 and 7). We show that although singers and non-singers felt equally connected by timepoint 3, singers experienced much faster bonding: singers demonstrated a significantly greater increase in closeness at timepoint 1, but the more gradual increase shown by non-singers caught up over time. This represents the first evidence for an 'ice-breaker effect' of singing in promoting fast cohesion between unfamiliar individuals, which bypasses the need for personal knowledge of group members gained through prolonged interaction. We argue that singing may have evolved to quickly bond large human groups of relative strangers, potentially through encouraging willingness to coordinate by enhancing positive affect. PMID:26587241

  9. Numerical Simulation of the Laval Annular Mechanical Foam Breaker for Foam Drilling

    Directory of Open Access Journals (Sweden)

    Pin Lu Cao

    2013-12-01

    Full Text Available The Computational Fluid Dynamics (CFD code, Fluent, is employed to simulate the flow phenomena inside the annular foam breaker in order to improve its performance. The numerical simulation results show that the value and the distribution of the negative pressure are very important for the annular foam breaker. The design of the Laval nozzle not only can increase the fluid velocity, but also can reduce the pressure value from -30.2 to -50.3 kPa compared with the common annular nozzle foam breaker. In order to improve the range of the internal negative pressure, the two-stage Laval annular foam breaker is designed in this study. The analysis results show the distance between the two annular slit have greatly influence on its performance. There is a small overlap area between the two negative pressure zones generated by the two annular slits. The smaller the value distance is, the larger the overlap zone is. When the value of the distance decreases to 50 mm, the minimum negative pressure can be reduced to approximately -65.5 kPa. Meanwhile, the range of the internal negative pressure is larger than the single Laval annular foam breaker, which is benefit to break foam.

  10. Design of a New Type of Distribution Valve for Hydraulic Breaker and Analysis of Energy Consumption

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Energy consumed by distribution valves causes an energy loss for the output energy of hydraulic breakers, which has a significant influence on its efficiency. A new type of distribution valve used for hydraulic breakers, designed to reduce energy consumption, is analyzed on the basis of the operating principle and energy loss of the current distribution valve. The new distribution valve adopts a cone valve and the optimization technique of unequal open degree for the valve port. Theoretical calculations and analyses have proven that the new distribution valve can reduce energy loss by 9.0127J, or energy consumption by 31%, during an impact cycle and the efficiency of the hydraulic breaker can be raised by 4.5%. It has the following characteristics: little leakage, little pressure loss and low energy consumption.

  11. Short Circuit Mechanical Force Withstand Capability Test%短路机械力耐受能力试验

    Institute of Scientific and Technical Information of China (English)

    朱英浩

    2001-01-01

    论述了变压器短路电流的动态力效应和断路器重合闸时变压器发热的影响,分析了变压器短路耐受试验有效性和剩磁对短路电流的影响,对预先短路法与后短路法进行了比较,还给出了短路电流的计算式。%The dynamic force effect of short circuit current in transformerand the influence on the heating of transformer when circuit breaker recloses are expouded. The effectiveness of transformer short circuit withstand test and the influence of residual flux on short circuit current are analysed. Preshort-circuit method is compared with postshort-circuit method, and calculation formulas of short circuit current are given.

  12. A study of plunging breaker mechanics by PIV measurements and a Navier-Stokes solver

    DEFF Research Database (Denmark)

    Emarat, Narumon; Forehand, David I. M.; Christensen, Erik Damgaard;

    2000-01-01

    The mechanics of a surf-zone plunging breaker are studied from Particle Image Velocimetry (PIV) measurements and a numerical model based on the Navier-Stokes equations, using a Volume of Fluid (VOF) method. An additional numerical model using a Boundary-Integral Method (BIM) is also used in order...

  13. Experimental and numerical investigation of the internal kinetics of a surf-zone plunging breaker

    DEFF Research Database (Denmark)

    Emarat, Narumon; Forehand, David I.M.; Christensen, Erik Damgaard;

    2012-01-01

    for surfzone breaking waves have been reported. In this study, a comparison is made between the experimental and numerical investigation of the internal kinematics of a surf-zone plunging breaker. The full-field velocity measuring technique known as Particle Image Velocimetry (PIV) is used in the experiments...

  14. Formation and Development of a Breaker Bar under Regular Waves. Part 1: Model Description and Hydrodynamics

    DEFF Research Database (Denmark)

    Jacobsen, Niels Gjøl; Fredsøe, Jørgen; Hjelmager Jensen, Jacob

    2014-01-01

    -shore sediment transport and morphodynamic response are considered. All simulations are presented for regular waves and for values of the deep-water surf similarity parameter, ζ0, in the range from 0.08 to 1.19, i.e. covering both spilling and plunging breakers. © 2014 Elsevier B.V. All rights reserved....

  15. Circuit Training.

    Science.gov (United States)

    Nelson, Jane B.

    1998-01-01

    Describes a research-based activity for high school physics students in which they build an LC circuit and find its resonant frequency of oscillation using an oscilloscope. Includes a diagram of the apparatus and an explanation of the procedures. (DDR)

  16. Controllable circuit

    DEFF Research Database (Denmark)

    2010-01-01

    A switch-mode power circuit comprises a controllable element and a control unit. The controllable element is configured to control a current in response to a control signal supplied to the controllable element. The control unit is connected to the controllable element and provides the control...

  17. EDA circuit simulation

    International Nuclear Information System (INIS)

    EDA technique is used for circuit simulation. The circuit simulation and the analysis are made for a gate circuit one-shot multivibrator. The result shows: EDA circuit simulation is very useful technique

  18. Analog and VLSI circuits

    CERN Document Server

    Chen, Wai-Kai

    2009-01-01

    Featuring hundreds of illustrations and references, this book provides the information on analog and VLSI circuits. It focuses on analog integrated circuits, presenting the knowledge on monolithic device models, analog circuit cells, high performance analog circuits, RF communication circuits, and PLL circuits.

  19. Lagrangian kinematics of steep waves up to the inception of a spilling breaker

    CERN Document Server

    Shemer, Lev

    2013-01-01

    Horizontal Lagrangian velocities and accelerations at the surface of steep water-waves are studied by Particle Tracking Velocimetry (PTV) for gradually increasing crest heights up to the inception of a spilling breaker. Localized steep waves are excited using wavemaker-generated Peregrine breather-type wave trains. Actual crest and phase velocities are estimated from video recorded sequences of the instantaneous wave shape as well as from surface elevation measurements by wave gauges. Effects of nonlinearity and spectral width on phase velocity, as well as relation between the phase velocity and crest propagation speed are discussed. The inception of a spilling breaker is associated with the horizontal velocity of water particles at the crest attaining that of the crest, thus confirming the kinematic criterion for inception of breaking.

  20. Detusking fence-breaker elephants as an approach in human-elephant conflict mitigation.

    Directory of Open Access Journals (Sweden)

    Matthew Mutinda

    Full Text Available Human-elephant conflict (HEC is a recurring problem that appears wherever the range of elephants and humans overlap. Different methods including the use of electric fences are used worldwide to mitigate this conflict. Nonetheless, elephants learn quickly that their tusks do not conduct electricity and use them to break down fences (fence-breakers.In Lewa Wildlife Conservancy, Kenya, destructive elephants (Loxodonta africana were monitored between 2010 and 2013. The fence-breaking rate reached four incidents (fence-breaking per elephant per 100 days. Ten bull males and 57 females were identified as fence-breakers. The bulls were involved in 85.07% and the females in 14.93% of incidents. The Kenya Wildlife Service approved detusking (partial cutting of tusks in four of the 10 fence-breakers as a way of preventing them from breaking down fences, thereby mitigating HEC in the Conservancy. The result of the detusking was a drastic six-fold reduction in damage to fences (range: 1.67 to 14.5 times less fence-breaking by the four worst fence-breaker elephants, because with trimmed tusks elephants lack the tools to break down fences. Detusking could not totally eliminate fence destruction because, despite lacking their tools, elephants can still destroy fences using their heads, bodies and trunks, albeit less effectively. On the other hand, apart from inherent aesthetic considerations, the detusking of elephants may have certain negative effects on factors such as elephants' social hierarchies, breeding, mate selection and their access to essential minerals and food.Elephant detusking seems to be effective in drastically reducing fence-breaking incidents, nonetheless its negative effects on behaviour, access to food and its aesthetical consequences still need to be further studied and investigated.

  1. Cross-shore redistribution of nourished sand near a breaker bar

    DEFF Research Database (Denmark)

    Jacobsen, Niels Gjøl; Fredsøe, Jørgen

    2014-01-01

    This paper focuses on the optimal location for dumping nourished sand on a barred coastline. This is done by investigating the short-term behavior of the cross-shore redistribution of nourished sediment on a breaker-bar profile in a two-dimensional vertical plane. This is achieved by the use of a...... bar can have both destructive and protective impacts on the original shoreward-located cross-shore profile....

  2. 锦屏二级水电站10 kV开关保护防跳回路异常分析%Anomaly Analysis of 10 kV Switch Protection Anti-Jump Circuit in Jinping Two Stage Hydropower Station

    Institute of Scientific and Technical Information of China (English)

    陈强; 曹钢; 王文松; 王为浩; 陈熙平

    2014-01-01

    Analysis was made to the abnormal switch position indication of 10 kV internal leakage drainage pump in Jinping two stage hydro-power station and the problem that the circuit breaker couldn’t be closed again later on. By comparing Nari protection anti-jump circuit switch with Schneider body anti-jump circuit which the circuit breaker configured, the application ranges for protection anti-jump circuit and body anti-jump circuit were obtained. This paper proposed four kinds of improved anti-jump circuit-breaker circuits and compared each advantage.%分析了锦屏二级水电站10 kV厂内渗漏排水泵开关位置指示异常,且断路器分闸后无法再次合上的问题,对比了断路器配置的南瑞保护防跳回路和施耐德开关本体防跳回路的差异,得出保护防跳回路和断路器本体防跳回路应用范围,提出了四种断路器防跳回路的改进方案,并比较了各自的优缺点。

  3. Hydrodynamic characteristics and geometric properties of plunging and spilling breakers over impermeable slopes

    Science.gov (United States)

    Alagan Chella, Mayilvahanan; Bihs, Hans; Myrhaug, Dag; Muskulus, Michael

    2016-07-01

    The two-phase flow CFD model REEF3D has been used for modeling waves breaking over a sloping seabed for a spilling and a plunging breaker. This model is based on Reynolds-averaged Navier-Stokes (RANS) equations with the level set method (LSM) for the free surface and k-ω model for turbulence. First, the characteristics and geometric properties of plunging breaking waves with different offshore wave steepnesses over slopes are examined and discussed. The study further explores the hydrodynamic characteristics of spilling and plunging breakers in terms of the wave height evolution and attenuation, horizontal and vertical velocity, free surface profile evolution, and the geometric properties during the development of the breaking process. The numerical results show a good agreement with experimental data in terms of free surface elevation, horizontal and vertical velocity, wave envelope and turbulent intensity for the spilling and plunging breakers. Results of numerical simulations describing the physical flow characteristics such as the formation of the forward overturning water jet, air pocket, splash-up, and the secondary wave during the breaking process are presented for both cases. For both cases, the physical flow process is found to have similar flow features, but the breaking process occurs at significantly different scales.

  4. The Danish Curve Breaker Agreement model - a voluntary agreement to break the electricity consumption curve

    Energy Technology Data Exchange (ETDEWEB)

    Jarby, Christian (Public Sector Affairs, The Danish Electricity Saving Trust (Denmark)); Pagh Nielsen, Karen Marie (Alectia A/S (Denmark)); Fjordbak, Troels (IT Energy ApS (Denmark))

    2009-07-01

    Both the public and private company sectors are continually acquiring more electrically powered equipment. Consequently, electricity consumption has risen by more than 1% per year over the last 10 years in Denmark (Danish Energy Agency, 2008). Curve Breaker Agreements were introduced in Denmark in 2007 by The Danish Electricity Saving Trust, an independent institution led by a Board appointed by the Danish Ministry of Climate and Energy. The agreements commit organisations and companies signing the agreements to reduce their electricity consumption and 'break the rising electricity curve', typically over a 3-year period. This paper describes the Curve Breaker Agreement model and analyses the effectiveness of initiatives and solutions in different agreements. The analysis is based on empirical research covering 115 agreements concluded by 18 March 2009. The research also includes remotely metered electricity consumption data and interviews with agreeing partners. The results showed that agreements should be concluded at macro level. An important precondition of the agreement follow-up process is that both parties should be able to track the electricity consumption of an individual organisation on a website. 115 agreements have been concluded in about 2 years, and by December 2008 the list of signatories included one third of all Danish municipalities, government ministries and public sector institutions, as well as a number of large private companies. The latest survey of electricity consumption in the Danish public sector indicates that the consumption curve by signatories of Curve Breaker Agreements has generally been broken, and is heading lower.

  5. Collective of mechatronics circuit

    International Nuclear Information System (INIS)

    This book is composed of three parts, which deals with mechatronics system about sensor, circuit and motor. The contents of the first part are photo sensor of collector for output, locating detection circuit with photo interrupts, photo sensor circuit with CdS cell and lamp, interface circuit with logic and LED and temperature sensor circuit. The second part deals with oscillation circuit with crystal, C-R oscillation circuit, F-V converter, timer circuit, stability power circuit, DC amp and DC-DC converter. The last part is comprised of bridge server circuit, deformation bridge server, controlling circuit of DC motor, controlling circuit with IC for PLL and driver circuit of stepping motor and driver circuit of Brushless.

  6. Analog circuit design designing dynamic circuit response

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    This second volume, Designing Dynamic Circuit Response builds upon the first volume Designing Amplifier Circuits by extending coverage to include reactances and their time- and frequency-related behavioral consequences.

  7. Photomultiplier blanking circuit

    Science.gov (United States)

    Mcclenahan, J. O.

    1972-01-01

    Circuit for protecting photomultiplier equipment from current surges which occur when exposed to brilliant illumination is discussed. Components of circuit and details of operation are provided. Circuit diagram to show action of blanking pulse on zener diode is included.

  8. Analog circuit design designing waveform processing circuits

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    The fourth volume in the set Designing Waveform-Processing Circuits builds on the previous 3 volumes and presents a variety of analog non-amplifier circuits, including voltage references, current sources, filters, hysteresis switches and oscilloscope trigger and sweep circuitry, function generation, absolute-value circuits, and peak detectors.

  9. El uso de los "ice breakers" en la orientación de las asignaturas

    OpenAIRE

    Galván Vallina, Joaquín; Gutiérrez Duarte, María Victoria

    2012-01-01

    El proceso de renovación pedagógica que ha supuesto el Espacio Europeo de Educación Superior (EEES) conduce a una nueva orientación en el desarrollo de las asignaturas. Con arreglo a estos planteamientos, se ha desarrollado el uso de los Ice Breakers (actividades para romper el hielo) con el objetivo de que el alumno se integre en la dinámica de la asignatura, superando la desconfianza y el recelo iniciales que se presentan ante una materia nueva y/o un grupo nuevo de compañeros de clase. En ...

  10. A novel advanced glycation endproducts breaker restores cardiovascular dysfunctions in experimental diabetic rats

    Institute of Scientific and Technical Information of China (English)

    GangCHENG; Li-liWANG; Hong-yingLIU; HaoCUI; Ying-linCAO; SongLI

    2005-01-01

    AIM The formation of advanced glycation endproducts (AGEs) on connective tissue and matrix components leads to increases in collagen crosslinkingthat contributes to aortic and myocardial stiffness in normal aging and which occurs at an accelerated rate in diabetes. In this study, we examined the effects of a novel AGEs breaker, C36, on cardiovascular dysfunctions in experimental diabetic rats. METHODS and RESULTS Male Wiatar rats were made diabetic by i.p. injection of 70mg/kg streptozotocin. After 12 weeks of diabetes, the animals were randomly divided into 4 groups (n=8-11),

  11. Design of the Control Interface of Reactor Trip Breaker in Nuclear Power Plant%核电厂停堆断路器停堆控制接口设计

    Institute of Scientific and Technical Information of China (English)

    周叶翔; 田亚杰; 任立永; 刘光明; 江辉

    2015-01-01

    In PWR nuclear power plants, the reactor trip breakers are commonly used as the actuators of emergency reactor trip system. Through researching and analyzing various existing trip control interface schemes, two hidden dangers in current designing schemes are pointed out, i. e. , the load of the trip coil don' t match with the load capacity of the control platform;and the circuit coupling is existing among control loops of the under voltage coils of trip breakers. To against these two problems, in accordance with related standards and regulations, improving schemes are proposed respectively by using dioxide circuit decoupling method and intermediate relay decoupling method, these provide reference for designing trip control interface of subsequent nuclear power plants.%压水堆核电厂普遍采用停堆断路器作为紧急停堆系统的执行机构. 通过对当前多种停堆控制接口方案的研究分析,指出当前的设计方案在某些工作瞬态下存在两个隐患:停堆线圈的负载与控制平台的带载能力失配;停堆断路器欠压线圈控制回路间存在电路耦合. 针对这两个问题,根据相关标准法规要求,采用二极管电路解耦方法及中间继电器解耦方法,分别提出一种改进方案,为后续核电厂停堆控制接口的设计及改造提供参考.

  12. Solid-state circuits

    CERN Document Server

    Pridham, G J

    2013-01-01

    Solid-State Circuits provides an introduction to the theory and practice underlying solid-state circuits, laying particular emphasis on field effect transistors and integrated circuits. Topics range from construction and characteristics of semiconductor devices to rectification and power supplies, low-frequency amplifiers, sine- and square-wave oscillators, and high-frequency effects and circuits. Black-box equivalent circuits of bipolar transistors, physical equivalent circuits of bipolar transistors, and equivalent circuits of field effect transistors are also covered. This volume is divided

  13. Circuit analysis for dummies

    CERN Document Server

    Santiago, John

    2013-01-01

    Circuits overloaded from electric circuit analysis? Many universities require that students pursuing a degree in electrical or computer engineering take an Electric Circuit Analysis course to determine who will ""make the cut"" and continue in the degree program. Circuit Analysis For Dummies will help these students to better understand electric circuit analysis by presenting the information in an effective and straightforward manner. Circuit Analysis For Dummies gives you clear-cut information about the topics covered in an electric circuit analysis courses to help

  14. Development of a test for water-in-oil emulsion breakers

    International Nuclear Information System (INIS)

    Studies have been conducted on the breaking of water-in-oil emulsions to develop a standard test for emulsion breaking agents, to test commercial products, and to understand the physics of emulsions. A review of the literature on the physics of emulsification is presented, showing the effects on emulsion formation of polar and asphaltene compounds in the oil. Nine basic test methods and several variations of each were developed, with successive tests developed to solve problems noted with earlier tests. The tests had to have a high degree of repeatability, aspects of the test methods had to be analogous to the sea and the practical application of emulsion breaking agents, and the test results had to relate to physical understanding of phenomena. Once a basic test was established, a series of studies was conducted to examine optimal time of shaking, the possibility of substituting settling time for shaking time, the relationship between energy of shaking and demuslfier effectiveness, and the effects of water to oil ratios. The studies show that a test for emulsion breakers can be developed to yield consistent results which are not entirely dependent on the shaking methods or vessels. The critical factor is the stability of the emulsion being tested, since unstable emulsions will show anomalous results. Other major factors are the type of emulsion breaker being tested and the determination of endpoint. 17 refs. 17 figs., 18 tabs

  15. 基于PAC&GPRS的高压直流开关振荡回落参数在线监测系统%On-line monitoring system of HVDC breaker based on PAC and GPRS

    Institute of Scientific and Technical Information of China (English)

    金涛; 蔡超; 王俊; 阮玲

    2013-01-01

    针对传统的离线式高压直流开关监测方法的诸多不足,为了能够实时地掌握直流开关的振荡回路的工作状态,在线计算出高压直流开关的状态参数,提出一种基于PAC(Programmable Automation Controller)和GPRS(General Packet Radio Service)的高压直流开关的在线监测方法.该方法通过采用霍尔传感器将振荡回路的振荡电流信号线性转换为电压信号,再通过PAC高数采样模块采集该电压信号,将采集到的振荡信号在本地存储之后再通过GPRS无线传输技术将采集到的数据传回后台数据处理中心,后台数据处理中心在线处理分析数据,得出RLC的参数值.实验室和葛洲坝换流站的实验表明,该系统对电力系统运行无任何影响,同时该系统能够准确地、高精度地采集振荡信号,正确地计算出振荡回路RLC参数,为准确获取高压直流开关的工作状态提供有利基础.%In order to get the real-time operating state of the oscillation circuit of the high voltage direct circuit (HVDC) breaker,and calculate the RLC parameters of the oscillation circuit,an on-line monitoring system of HVDC breaker's oscillation circuit is put forward based on the programmable automation controller (PAC) data acquisition technique.The hardware and software are designed to achieve this goal.In this system,a Hall sensor is used to linearly transform the oscillation current into voltage signal; then the voltage is gathered by PAC data acquisition system; after stored on local disk of PAC,the data is transmitted to the data processing center.After these,the RLC parameters of the oscillation circuit could be calculated automatically.With this on-line monitoring system of DC breaker's oscillation circuit,we have done experiments in our laboratory and in Gezhouba convertor station.The experimental data prove that this system does not have any impact on the electric power system; the most important is that it can accurately acquire

  16. 智能断路器抗EFT/B干扰滤波器设计%Filter design of resistance to interference of electrical fast transient/burst in intelligent gircuit breaker

    Institute of Scientific and Technical Information of China (English)

    佟为明; 张忠; 李中伟; 王胤燊

    2012-01-01

    To improve the performance of intelligent circuit breaker of resisting the interference of electrical fast transienl/burst (EFT/B) , an EFT/B interference source equivalent circuit model in accordance with the analysis of the generation mechanism and characteristics of EFT/B was created and the circuit state equation was established, a new Levenberg-Marquardt method was proposed to optimize the extended Kalman filter( EKF) algorithm on the basis of Taylor expansion, the derivation process of new theory was given and tracking performance and root mean square error (RMS error) was analyzed through the simulation experiment of EFT/B interference current transformer system which generated the EKF simulation results and evidence for the method was provided. Experimental results show that the improved EKF has higher estimate accuracy and stability and can improve the ability of resistance interference of the intelligent circuit breaker for EFT/B effectively.%为了提高智能断路器抗电快速瞬变脉冲群(EFT/B)干扰性,依据EFT/B形成和作用机理分析,建立EFT/B干扰源等效电路模型,给出电路状态方程;基于泰勒展开公式,提出了一种Levenberg-Marquardt优化扩展卡尔曼滤波算法,给出了方法的理论推导过程,并通过EFT/B干扰电流互感器系统仿真实验,给出了该方法与扩展卡尔曼滤波(EKF)仿真结果,并分析了跟踪性能和均方根误差.实验结果表明:改进的卡尔曼滤波器(NIEKF)具有更高的估计精确度和稳定性,该方法设计的扩展卡尔曼滤波器可有效提高智能断路器抗电快速瞬变脉冲群干扰能力.

  17. Incremento del porcentaje de breakers que pasan la calibración magnética en la linea FA Maggard para Schneider Electric

    OpenAIRE

    Gamboa Corzas, Ramón

    2005-01-01

    El objetivo principal de este trabajo consistió en incrementar el porcentaje de breakers que pasan la prueba de calibración magnética en la linea de ensamble de breakers FA Maggard en la empresa Schneider Electric. El problema principal es que el porcentaje de breakers que pasan la calibración magnética en esta línea ha sido tan solo del 80% en los meses de mayo, junio y julio del 2005, ocasionando por consecuencia una eficiencia del 60%, un retrabajo de 76 hrs. mensuales y ...

  18. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1972-01-01

    Electronic Devices and Circuits, Volume 3 provides a comprehensive account on electronic devices and circuits and includes introductory network theory and physics. The physics of semiconductor devices is described, along with field effect transistors, small-signal equivalent circuits of bipolar transistors, and integrated circuits. Linear and non-linear circuits as well as logic circuits are also considered. This volume is comprised of 12 chapters and begins with an analysis of the use of Laplace transforms for analysis of filter networks, followed by a discussion on the physical properties of

  19. The circuit designer's companion

    CERN Document Server

    Williams, Tim

    2013-01-01

    The Circuit Designer's Companion covers the theoretical aspects and practices in analogue and digital circuit design. Electronic circuit design involves designing a circuit that will fulfill its specified function and designing the same circuit so that every production model of it will fulfill its specified function, and no other undesired and unspecified function.This book is composed of nine chapters and starts with a review of the concept of grounding, wiring, and printed circuits. The subsequent chapters deal with the passive and active components of circuitry design. These topics are foll

  20. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  1. Record breakers

    CERN Multimedia

    Antonella Del Rosso

    2012-01-01

    In the sixties, CERN’s Fellows were but a handful of about 50 young experimentalists present on site to complete their training. Today, their number has increased to a record-breaking 500. They come from many different fields and are spread across CERN’s different activity areas.   “Diversifying the Fellowship programme has been the key theme in recent years,” comments James Purvis, Head of the Recruitment, Programmes and Monitoring group in the HR Department. “In particular, the 2005 five-yearly review introduced the notion of ‘senior’ and ‘junior’ Fellowships, broadening the target audience to include those with Bachelor-level qualifications.” Diversification made CERN’s Fellowship programme attractive to a wider audience but the number of Fellows on site could not have increased so much without the support of EU-funded projects, which were instrumental in the growth of the programme. ...

  2. Electrical Circuits and Water Analogies

    Science.gov (United States)

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  3. The Impact Of Surface Shape Of Chip-Breaker On Machined Surface

    Science.gov (United States)

    Šajgalík, Michal; Czán, Andrej; Martinček, Juraj; Varga, Daniel; Hemžský, Pavel; Pitela, David

    2015-12-01

    Machined surface is one of the most used indicators of workpiece quality. But machined surface is influenced by several factors such as cutting parameters, cutting material, shape of cutting tool or cutting insert, micro-structure of machined material and other known as technological parameters. By improving of these parameters, we can improve machined surface. In the machining, there is important to identify the characteristics of main product of these processes - workpiece, but also the byproduct - the chip. Size and shape of chip has impact on lifetime of cutting tools and its inappropriate form can influence the machine functionality and lifetime, too. This article deals with elimination of long chip created when machining of shaft in automotive industry and with impact of shape of chip-breaker on shape of chip in various cutting conditions based on production requirements.

  4. Circuits on Cylinders

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Miltersen, Peter Bro; Vinay, V

    2006-01-01

    We consider the computational power of constant width polynomial size cylindrical circuits and nondeterministic branching programs. We show that every function computed by a Pi2 o MOD o AC0 circuit can also be computed by a constant width polynomial size cylindrical nondeterministic branching...... program (or cylindrical circuit) and that every function computed by a constant width polynomial size cylindrical circuit belongs to ACC0....

  5. Electric circuits essentials

    CERN Document Server

    REA, Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Electric Circuits I includes units, notation, resistive circuits, experimental laws, transient circuits, network theorems, techniques of circuit analysis, sinusoidal analysis, polyph

  6. Inhibition of aggregation of amyloid peptides by beta-sheet breaker peptides and their binding affinity.

    Science.gov (United States)

    Viet, Man Hoang; Ngo, Son Tung; Lam, Nguyen Sy; Li, Mai Suan

    2011-06-01

    The effects of beta-sheet breaker peptides KLVFF and LPFFD on the oligomerization of amyloid peptides were studied by all-atom simulations. It was found that LPFFD interferes the aggregation of Aβ(16-22) peptides to a greater extent than does KLVFF. Using the molecular mechanics-Poisson-Boltzmann surface area (MM-PBSA) method, we found that the former binds more strongly to Aβ(16-22). Therefore, by simulations, we have clarified the relationship between aggregation rates and binding affinity: the stronger the ligand binding, the slower the oligomerization process. The binding affinity of pentapeptides to full-length peptide Aβ(1-40) and its mature fibrils has been considered using the Autodock and MM-PBSA methods. The hydrophobic interaction between ligands and receptors plays a more important role for association than does hydrogen bonding. The influence of beta-sheet breaker peptides on the secondary structures of monomer Aβ(1-40) was studied in detail, and it turns out that, in their presence, the total beta-sheet content can be enhanced. However, the aggregation can be slowed because the beta-content is reduced in fibril-prone regions. Both pentapeptides strongly bind to monomer Aβ(1-40), as well as to mature fibrils, but KLVFF displays a lower binding affinity than LPFFD. Our findings are in accord with earlier experiments that both of these peptides can serve as prominent inhibitors. In addition, we predict that LPFFD inhibits/degrades the fibrillogenesis of full-length amyloid peptides better than KLVFF. This is probably related to a difference in their total hydrophobicities in that the higher the hydrophobicity, the lower the inhibitory capacity. The GROMOS96 43a1 force field with explicit water and the force field proposed by Morris et al. (Morris et al. J. Comput. Chem. 1998, 19, 1639 ) were employed for all-atom molecular dynamics simulations and Autodock experiments, respectively. PMID:21563780

  7. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, Simon Minze; Vertregt, Maarten

    2010-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital converte

  8. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, Simon Minze; Vertregt, Maarten

    2011-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital converte

  9. Piezoelectric drive circuit

    Science.gov (United States)

    Treu, Jr., Charles A.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes.

  10. Short-circuit logic

    NARCIS (Netherlands)

    J.A. Bergstra; A. Ponse

    2010-01-01

    Short-circuit evaluation denotes the semantics of propositional connectives in which the second argument is only evaluated if the first argument does not suffice to determine the value of the expression. In programming, short-circuit evaluation is widely used. A short-circuit logic is a variant of p

  11. Scaled photographs of surf over the full range of breaker sizes on the north shore of Oahu and Jaws, Maui, Hawaiian Islands (NODC Accession 0001753)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digital surf photographs were scaled using surfers as height benchmarks to estimate the size of the breakers. Historical databases for surf height in Hawaii are...

  12. Lightning Surge Analysis in 154 kV S/S due to Flashover on the 4 Circuits Tower

    Energy Technology Data Exchange (ETDEWEB)

    Woo, J. W.; Shim, E. B.; Kwak, J. S.; Choi, B. J. [Korea Electric Power Corporation (Korea)

    2000-07-01

    This paper describes the analysis results for the protection of lightning surge at 154 kV substation. We found that the surge arrester is needed at the inlet structure. The maximum overvoltage is about 1,500 kV at the circuit breaker without the surge arrester at the inlet structure. This value can be lower than 600 kV by installing the surge arrester at the inlet structure. In addition to the shield wire should be considered to prevent the shielding failure by the direct lightning stroke. (author). 6 refs., 8 figs.

  13. Practical microwave circuits

    CERN Document Server

    Maas, Stephen A

    2014-01-01

    This book differentiates itself by presenting microwave and RF technology from a circuit design viewpoint, rather than a set of electromagnetic problems. The emphasis is on gaining a practical understanding of often overlooked but vital physical processes.This resource provides microwave circuit engineers with analytical techniques for understanding and designing high-frequency circuits almost entirely from a circuit point of view. Electromagnetic concepts are not avoided, but they are employed only as necessary to support circuit-theoretical ones or to describe phenomena such as radiation and

  14. Exact Threshold Circuits

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Podolskii, Vladimir V.

    2010-01-01

    We initiate a systematic study of constant depth Boolean circuits built using exact threshold gates. We consider both unweighted and weighted exact threshold gates and introduce corresponding circuit classes. We next show that this gives a hierarchy of classes that seamlessly interleave with the ......We initiate a systematic study of constant depth Boolean circuits built using exact threshold gates. We consider both unweighted and weighted exact threshold gates and introduce corresponding circuit classes. We next show that this gives a hierarchy of classes that seamlessly interleave...... with the well-studied corresponding hierarchies defined using ordinary threshold gates. A major open problem in Boolean circuit complexity is to provide an explicit super-polynomial lower bound for depth two threshold circuits. We identify the class of depth two exact threshold circuits as a natural subclass...

  15. Feedback in analog circuits

    CERN Document Server

    Ochoa, Agustin

    2016-01-01

    This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...

  16. The analysis of failure circuit of 500 kV transformer protection%500 kV主变保护失灵回路分析

    Institute of Scientific and Technical Information of China (English)

    舒逸石; 魏民; 马勇

    2011-01-01

    Aiming at the particularity of failure circuit of 500 kV main transformer, this paper discusses the logic principle of start Up failure circuit at high-pressure side and middle-pressure side.Through the analysis of the start-up and trip circuit of failure protection of main transformer, it points out the characteristic oftbe failure circuit in high-pressure side of main transformer is that “when the high side breaker refuses to trip, the breaker of three sides and the high-side associated will be tripped”, and the characteristic of the failure circuit in middle-pressure side transformer is that “when circuit-breaker failures, the complex voltage lockout should be removed and breaker location is not judged”.The failure start-up criterion of main transformer is educed, namely “current discrimination + power protection exit”, and the principle of electricity protection start up failure is that failure protection at the side which trips should be started.%针对500 kV主变失灵回路的特殊性,分别对主变高压侧、中压侧失灵启动回路的逻辑原理进行论述.通过对主变失灵保护的启动回路和跳闸回路的分析,总结了主变高压侧失灵回路的特点即"高压侧任一断路器拒动联跳主变三侧断路器并跳开高压侧相关断路器";中压侧断路器失灵回路的特点即"断路器失灵解除复压闭锁且不判断路器位置".得出了主变失灵启动的判据即"电流判别+电量保护出口",电量保护启动失灵的原则--跳哪侧断路器启动哪侧失灵.

  17. Analog circuits cookbook

    CERN Document Server

    Hickman, Ian

    2013-01-01

    Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

  18. Stochastic Switching Circuit Synthesis

    OpenAIRE

    Wilhelm, Daniel; Bruck, Jehoshua

    2009-01-01

    Shannon in his 1938 Masterpsilas Thesis demonstrated that any Boolean function can be realized by a switching relay circuit, leading to the development of deterministic digital logic. Here, we replace each classical switch with a probabilistic switch (pswitch). We present algorithms for synthesizing circuits closed with a desired probability, including an algorithm that generates optimal size circuits for any binary fraction. We also introduce a new duality property for series-parallel stocha...

  19. Regenerative feedback resonant circuit

    Science.gov (United States)

    Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

    2014-09-02

    A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

  20. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  1. Signal sampling circuit

    OpenAIRE

    Louwsma, Simon Minze; Vertregt, Maarten

    2011-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital converter via a respective output switch. The output switch of each channel opens for a tracking time period when the track-and-hold circuit is in a tracking mode for sampling the signal, and closes for a ...

  2. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1968-01-01

    Electronic Devices and Circuits, Volume 1 deals with the design and applications of electronic devices and circuits such as passive components, diodes, triodes and transistors, rectification and power supplies, amplifying circuits, electronic instruments, and oscillators. These topics are supported with introductory network theory and physics. This volume is comprised of nine chapters and begins by explaining the operation of resistive, inductive, and capacitive elements in direct and alternating current circuits. The theory for some of the expressions quoted in later chapters is presented. Th

  3. Security electronics circuits manual

    CERN Document Server

    MARSTON, R M

    1998-01-01

    Security Electronics Circuits Manual is an invaluable guide for engineers and technicians in the security industry. It will also prove to be a useful guide for students and experimenters, as well as providing experienced amateurs and DIY enthusiasts with numerous ideas to protect their homes, businesses and properties.As with all Ray Marston's Circuits Manuals, the style is easy-to-read and non-mathematical, with the emphasis firmly on practical applications, circuits and design ideas. The ICs and other devices used in the practical circuits are modestly priced and readily available ty

  4. CMOS circuits manual

    CERN Document Server

    Marston, R M

    1995-01-01

    CMOS Circuits Manual is a user's guide for CMOS. The book emphasizes the practical aspects of CMOS and provides circuits, tables, and graphs to further relate the fundamentals with the applications. The text first discusses the basic principles and characteristics of the CMOS devices. The succeeding chapters detail the types of CMOS IC, including simple inverter, gate and logic ICs and circuits, and complex counters and decoders. The last chapter presents a miscellaneous collection of two dozen useful CMOS circuits. The book will be useful to researchers and professionals who employ CMOS circu

  5. Timergenerator circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Timer/Generator Circuits Manual is an 11-chapter text that deals mainly with waveform generator techniques and circuits. Each chapter starts with an explanation of the basic principles of its subject followed by a wide range of practical circuit designs. This work presents a total of over 300 practical circuits, diagrams, and tables.Chapter 1 outlines the basic principles and the different types of generator. Chapters 2 to 9 deal with a specific type of waveform generator, including sine, square, triangular, sawtooth, and special waveform generators pulse. These chapters also include pulse gen

  6. Circuits and filters handbook

    CERN Document Server

    Chen, Wai-Kai

    2003-01-01

    A bestseller in its first edition, The Circuits and Filters Handbook has been thoroughly updated to provide the most current, most comprehensive information available in both the classical and emerging fields of circuits and filters, both analog and digital. This edition contains 29 new chapters, with significant additions in the areas of computer-aided design, circuit simulation, VLSI circuits, design automation, and active and digital filters. It will undoubtedly take its place as the engineer's first choice in looking for solutions to problems encountered in the design, analysis, and behavi

  7. MOS integrated circuit design

    CERN Document Server

    Wolfendale, E

    2013-01-01

    MOS Integral Circuit Design aims to help in the design of integrated circuits, especially large-scale ones, using MOS Technology through teaching of techniques, practical applications, and examples. The book covers topics such as design equation and process parameters; MOS static and dynamic circuits; logic design techniques, system partitioning, and layout techniques. Also featured are computer aids such as logic simulation and mask layout, as well as examples on simple MOS design. The text is recommended for electrical engineers who would like to know how to use MOS for integral circuit desi

  8. 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。

  9. A Virtual Circuits Lab

    Science.gov (United States)

    Vick, Matthew E.

    2010-01-01

    The University of Colorado's Physics Education Technology (PhET) website offers free, high-quality simulations of many physics experiments that can be used in the classroom. The Circuit Construction Kit, for example, allows students to safely and constructively play with circuit components while learning the mathematics behind many circuit…

  10. Synchronizing Hyperchaotic Circuits

    DEFF Research Database (Denmark)

    Tamasevicius, Arunas; Cenys, Antanas; Namajunas, Audrius;

    1997-01-01

    Regarding possible applications to secure communications the technique of synchronizing hyperchaotic circuits with a single dynamical variable is discussed. Several specific examples including the fourth-order circuits with two positive Lyapunov exponents as well as the oscillator with a delay line...

  11. Approximate circuits for increased reliability

    Energy Technology Data Exchange (ETDEWEB)

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-12-22

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  12. Approximate circuits for increased reliability

    Energy Technology Data Exchange (ETDEWEB)

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-08-18

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  13. Optoelectronics circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Optoelectronics Circuits Manual covers the basic principles and characteristics of the best known types of optoelectronic devices, as well as the practical applications of many of these optoelectronic devices. The book describes LED display circuits and LED dot- and bar-graph circuits and discusses the applications of seven-segment displays, light-sensitive devices, optocouplers, and a variety of brightness control techniques. The text also tackles infrared light-beam alarms and multichannel remote control systems. The book provides practical user information and circuitry and illustrations.

  14. Circuit analysis with Multisim

    CERN Document Server

    Baez-Lopez, David

    2011-01-01

    This book is concerned with circuit simulation using National Instruments Multisim. It focuses on the use and comprehension of the working techniques for electrical and electronic circuit simulation. The first chapters are devoted to basic circuit analysis.It starts by describing in detail how to perform a DC analysis using only resistors and independent and controlled sources. Then, it introduces capacitors and inductors to make a transient analysis. In the case of transient analysis, it is possible to have an initial condition either in the capacitor voltage or in the inductor current, or bo

  15. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

    Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

  16. Load testing circuit

    DEFF Research Database (Denmark)

    2009-01-01

    A load testing circuit a circuit tests the load impedance of a load connected to an amplifier. The load impedance includes a first terminal and a second terminal, the load testing circuit comprising a signal generator providing a test signal of a defined bandwidth to the first terminal of the load...... impedance, an energy-storing element being connected to the second terminal of the load impedance and providing an output signal, and a measuring unit that measures the output signal or compares the output signal with a reference....

  17. Modern TTL circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Modern TTL Circuits Manual provides an introduction to the basic principles of Transistor-Transistor Logic (TTL). This book outlines the major features of the 74 series of integrated circuits (ICs) and introduces the various sub-groups of the TTL family.Organized into seven chapters, this book begins with an overview of the basics of digital ICs. This text then examines the symbology and mathematics of digital logic. Other chapters consider a variety of topics, including waveform generator circuitry, clocked flip-flop and counter circuits, special counter/dividers, registers, data latches, com

  18. Plasmonic Nanoguides and Circuits

    CERN Document Server

    Bozhevolnyi, Sergey

    2008-01-01

    Modern communication systems dealing with huge amounts of data at ever increasing speed try to utilize the best aspects of electronic and optical circuits. Electronic circuits are tiny but their operation speed is limited, whereas optical circuits are extremely fast but their sizes are limited by diffraction. Waveguide components utilizing surface plasmon (SP) modes were found to combine the huge optical bandwidth and compactness of electronics, and plasmonics thereby began to be considered as the next chip-scale technology. In this book, the authors concentrate on the SP waveguide configurati

  19. Pragmatic circuits frequency domain

    CERN Document Server

    Eccles, William

    2006-01-01

    Pragmatic Circuits: Frequency Domain goes through the Laplace transform to get from the time domain to topics that include the s-plane, Bode diagrams, and the sinusoidal steady state. This second of three volumes ends with a-c power, which, although it is just a special case of the sinusoidal steady state, is an important topic with unique techniques and terminology. Pragmatic Circuits: Frequency Domain is focused on the frequency domain. In other words, time will no longer be the independent variable in our analysis. The two other volumes in the Pragmatic Circuits series include titles on DC

  20. Monolithic microwave integrated circuits

    Science.gov (United States)

    Pucel, R. A.

    Monolithic microwave integrated circuits (MMICs), a new microwave technology which is expected to exert a profound influence on microwave circuit designs for future military systems as well as for the commercial and consumer markets, is discussed. The book contains an historical discussion followed by a comprehensive review presenting the current status in the field. The general topics of the volume are: design considerations, materials and processing considerations, monolithic circuit applications, and CAD, measurement, and packaging techniques. All phases of MMIC technology are covered, from design to testing.

  1. Counting rate logarithmic circuits

    International Nuclear Information System (INIS)

    This paper describes the basic circuit and the design method for a multidecade logarithmic counting ratemeter. The method is based on the charging and discharging of several RC time constants. An F.E.T. switch is used and the drain current is converted into a proportional voltage by a current to voltage converter. The logarithmic linearity was estimated for 4 decades starting from 50 cps. This circuit can be used in several nuclear instruments like survey meters and counting systems. This circuits has been developed as part of campbell channel instrumentation. (author)

  2. C16, a novel advanced glycation endproduct breaker, restores cardiovascular dysfunction in experimental diabetic rats

    Institute of Scientific and Technical Information of China (English)

    Gang CHENG; Li-li WANG; Wen-sheng QU; Long LONG; Hao CUI; Hong-ying LIU; Ying-lin CAO; Song LI

    2005-01-01

    Aim: Advanced glycation endproducts (AGE) have been implicated in the pathogenesis of diabetic complications, including diabetic cardiovascular dysfunction.3-[2-(4-Bromo-phenyl)- 1-methyl-2-oxo-ethyl]-4,5,6,7-tetrahydro-benzothiazol-3-ium bromide (C16), a novel AGE breaker, was investigated for its effects on the development of cardiovascular disease in diabetic rats. Methods: Rats that had streptozotocin-induced diabetes for 12 weeks were divided into groups receiving C16 or vehicle by gavage. Results: In hemodynamic studies of the left ventricle,C16 treatment (25 or 50 mg/kg) for 4 weeks resulted in a significant increase in left ventricular systolic pressure, +dp/dtmax, and -dp/dtmax as compared with vehicletreated diabetic rats. Furthermore, in hemodynamic studies of the cardiovascular system, C16 (12.5, 25, or 50 mg/kg) treatment for 4 weeks resulted in a dosedependent and significant increase in cardiac output, a reduction of total peripheral resistance, and an increase in systemic arterial compliance when compared with vehicle-treated diabetic rats. Biochemical studies showed that C16 treatment also resulted in a significant decrease in immunoglobulin G-red blood cell surface crosslink content and an increase in collagen solubility. Morphological and immunohistochemical examinations indicated that C 16 was able to prevent increases of the collagen type Ⅲ/Ⅰ ratio in the aorta and decrease the accumulation of AGE in the aorta. Conclusion: C16 has the ability to reduce AGE accumulation in tissues in vivo, and can restore diabetes-associated cardiovascular disorders in rats. This provides a potential therapeutic approach for cardiovascular disease associated with diabetes and aging in humans.

  3. Printed circuit for ATLAS

    CERN Multimedia

    Laurent Guiraud

    1999-01-01

    A printed circuit board made by scientists in the ATLAS collaboration for the transition radiaton tracker (TRT). This will read data produced when a high energy particle crosses the boundary between two materials with different electrical properties.

  4. Synthetic in vitro circuits

    OpenAIRE

    Hockenberry, Adam J.; Jewett, Michael C.

    2012-01-01

    Inspired by advances in the ability to construct programmable circuits in living organisms, in vitro circuits are emerging as a viable platform for designing, understanding, and exploiting dynamic biochemical circuitry. In vitro systems allow researchers to directly access and manipulate biomolecular parts without the unwieldy complexity and intertwined dependencies that often exist in vivo. Experimental and computational foundations in DNA, DNA/RNA, and DNA/RNA/protein based circuitry have g...

  5. Chelation: a fundamental mechanism of action of AGE inhibitors, AGE breakers, and other inhibitors of diabetes complications.

    Science.gov (United States)

    Nagai, Ryoji; Murray, David B; Metz, Thomas O; Baynes, John W

    2012-03-01

    This article outlines evidence that advanced glycation end product (AGE) inhibitors and breakers act primarily as chelators, inhibiting metal-catalyzed oxidation reactions that catalyze AGE formation. We then present evidence that chelation is the most likely mechanism by which ACE inhibitors, angiotensin receptor blockers, and aldose reductase inhibitors inhibit AGE formation in diabetes. Finally, we note several recent studies demonstrating therapeutic benefits of chelators for diabetic cardiovascular and renal disease. We conclude that chronic, low-dose chelation therapy deserves serious consideration as a clinical tool for prevention and treatment of diabetes complications.

  6. Peak reading detector circuit

    International Nuclear Information System (INIS)

    The peak reading detector circuit serves for picking up the instants during which peaks of a given polarity occur in sequences of signals in which the extreme values, their time intervals, and the curve shape of the signals vary. The signal sequences appear in measuring the foetal heart beat frequence from amplitude-modulated ultrasonic, electrocardiagram, and blood pressure signals. In order to prevent undesired emission of output signals from, e. g., disturbing intermediate extreme values, the circuit consists of the series connections of a circuit to simulate an ideal diode, a strong unit, a discriminator for the direction of charging current, a time-delay circuit, and an electronic switch lying in the decharging circuit of the storage unit. The time-delay circuit thereby causes storing of a preliminary maximum value being used only after a certain time delay for the emission of the output signal. If a larger extreme value occurs during the delay time the preliminary maximum value is cleared and the delay time starts running anew. (DG/PB)

  7. Characteristics of the Delayed Current-zero Crossing of Short-circuit Current Occurred in the UHV Series Compensated Transmission Line%特高压串补线路短路电流的延时过零特性

    Institute of Scientific and Technical Information of China (English)

    关永刚; 郭珮琪; 项祖涛; 徐国政; 刘卫东

    2015-01-01

    特高压串补线路故障时流经断路器的短路电流可能出现延时过零现象,给断路器的成功开断造成困难.依据中国1 000 kV同塔双回线路的典型参数,仿真分析了该现象的产生机制.双回线路中,故障回路串补保护装置MOV动作引起短路电流中的周期分量经非故障回路分流,是造成流经串补装置远端的断路器中短路电流过零延时的主要原因.就影响该现象的因素如故障类型、故障点位置、线路长度、串补布置方式以及串补度进行了探讨.根据仿真结果,建议采取串补分散布置和提高断路器开断性能来解决该问题,不建议特高压交流断路器加装分闸电阻.%The delayed current-zero crossing of short circuits current can happen in UHV systems with series-compensation when fault occurs and can create difficulties to the circuit breakers to interrupt. This paper analyzed the mechanism of the above phenomenon based on the typical parameters of 1000kV double circuit transmission line in China. The key reason for the delayed current-zero crossing of current passing through the circuit breaker which is far away from the series compensation is that the bypass flowing of periodic content of fault current through non-fault line which caused by the action of MOV in the series compensation. The factors that influenced the delayed current-zero crossing have been studied, such as fault type, fault location, line length, series compensator arrangement and series compensation degree. According to the simulation results, it is recommended to take the dispersed arrangement of series compensation and improve the capacity of circuit breaker to solve this problem, opposed to apply opening resistances on the circuit breaker in UHV line with series-compensation.

  8. Diagnosis technique for the detection of mechanical faults in power breakers; Tecnica de diagnostico para la deteccion de fallas mecanicas en interruptores de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Linan, Roberto; Perez, Marciano; Estrada, J. Manuel [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    This article reports a non-invasive diagnosis technique for the detection of mechanical faults in power breakers, supporting it with the recording and analysis of vibration signals of the equipment under test. Also, an assessment of four breakers using this technique is presented. [Espanol] En el presente articulo se reporta una tecnica de diagnostico no invasiva para detectar fallas mecanicas en interruptores de potencia, apoyandose en el registro y analisis de senales de vibracion del equipo bajo prueba. Asimismo, se presenta la evaluacion de cuatro interruptores usando esta tecnica.

  9. Chelation: A Fundamental Mechanism of Action of AGE Inhibitors, AGE Breakers, and Other Inhibitors of Diabetes Complications

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, Rhoji; Murray, David B.; Metz, Thomas O.; Baynes, John

    2012-03-01

    Advanced glycation or glycoxidation end-products (AGE) increase in tissue proteins with age, and their rate of accumulation is increased in diabetes, nephropathy and inflammatory diseases. AGE inhibitors include a range of compounds that are proposed to act by trapping carbonyl and dicarbonyl intermediates in AGE formation. However, some among the newer generation of AGE inhibitors lack reactive functional groups that would trap reaction intermediates, indicating an alternative mechanism of action. We propose that AGE inhibitors function primarily as chelators, inhibiting metal-catalyzed oxidation reactions. The AGE-inhibitory activity of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers is also consistent with their chelating activity. Finally, compounds described as AGE breakers, or their hydrolysis products, also have strong chelating activity, suggesting that these compounds also act through their chelating activity. We conclude that chelation is the common, and perhaps the primary, mechanism of action of AGE inhibitors and breakers, and that chronic, mild chelation therapy should prove useful in treatment of diabetes and age-related diseases characterized by oxidative stress, inflammation and increased chemical modification of tissue proteins by advanced glycoxidation and lipoxidation end-products.

  10. A semiconductor laser excitation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Kaadzunari, O.; Masaty, K.

    1984-03-27

    A semiconductor laser excitation circuit is patented that is designed for operation in a pulsed mode with a high pulse repetition frequency. This circuit includes, in addition to a semiconductor laser, a high speed photodetector, a reference voltage source, a comparator, and a pulse oscillator and modulator. If the circuit is built using standard silicon integrated circuits, its speed amounts to several hundred megahertz, if it is constructed using gallium arsenide integrated circuits, its speed is several gigahertz.

  11. The Mind Grows Circuits

    CERN Document Server

    Panigrahy, Rina

    2012-01-01

    There is a vast supply of prior art that study models for mental processes. Some studies in psychology and philosophy approach it from an inner perspective in terms of experiences and percepts. Others such as neurobiology or connectionist-machines approach it externally by viewing the mind as complex circuit of neurons where each neuron is a primitive binary circuit. In this paper, we also model the mind as a place where a circuit grows, starting as a collection of primitive components at birth and then builds up incrementally in a bottom up fashion. A new node is formed by a simple composition of prior nodes when we undergo a repeated experience that can be described by that composition. Unlike neural networks, however, these circuits take "concepts" or "percepts" as inputs and outputs. Thus the growing circuits can be likened to a growing collection of lambda expressions that are built on top of one another in an attempt to compress the sensory input as a heuristic to bound its Kolmogorov Complexity.

  12. Chaotic memristive circuit: equivalent circuit realization and dynamical analysis

    Institute of Scientific and Technical Information of China (English)

    Bao Bo-Cheng; Xu Jian-Ping; Zhou Guo-Hua; Ma Zheng-Hua; Zou Ling

    2011-01-01

    In this paper,a practical equivalent circuit of an active flux-controlled memristor characterized by smooth piecewise-quadratic nonlinearity is designed and an experimental chaotic memristive circuit is implemented.The chaotic memristive circuit has an equilibrium set and its stability is dependent on the initial state of the memristor.The initial state-dependent and the circuit parameter-dependent dynamics of the chaotic memristive circuit are investigated via phase portraits,bifurcation diagrams and Lyapunov exponents.Both experimental and simulation results validate the proposed equivalent circuit realization of the active flux-controlled memristor.

  13. Circuit Quantum Electrodynamics

    CERN Document Server

    Bishop, Lev S

    2010-01-01

    Circuit Quantum Electrodynamics (cQED), the study of the interaction between superconducting circuits behaving as artificial atoms and 1-dimensional transmission-line resonators, has shown much promise for quantum information processing tasks. For the purposes of quantum computing it is usual to approximate the artificial atoms as 2-level qubits, and much effort has been expended on attempts to isolate these qubits from the environment and to invent ever more sophisticated control and measurement schemes. Rather than focussing on these technological aspects of the field, this thesis investigates the opportunities for using these carefully engineered systems for answering questions of fundamental physics.

  14. Electronic circuits fundamentals & applications

    CERN Document Server

    Tooley, Mike

    2015-01-01

    Electronics explained in one volume, using both theoretical and practical applications.New chapter on Raspberry PiCompanion website contains free electronic tools to aid learning for students and a question bank for lecturersPractical investigations and questions within each chapter help reinforce learning Mike Tooley provides all the information required to get to grips with the fundamentals of electronics, detailing the underpinning knowledge necessary to appreciate the operation of a wide range of electronic circuits, including amplifiers, logic circuits, power supplies and oscillators. The

  15. Primer printed circuit boards

    CERN Document Server

    Argyle, Andrew

    2009-01-01

    Step-by-step instructions for making your own PCBs at home. Making your own printed circuit board (PCB) might seem a daunting task, but once you master the steps, it's easy to attain professional-looking results. Printed circuit boards, which connect chips and other components, are what make almost all modern electronic devices possible. PCBs are made from sheets of fiberglass clad with copper, usually in multiplelayers. Cut a computer motherboard in two, for instance, and you'll often see five or more differently patterned layers. Making boards at home is relatively easy

  16. Electronic circuit analysis

    CERN Document Server

    Kishore, K Lal

    2008-01-01

    Second Edition of the book Electronic Circuit Analysis is brought out with certain new Topics and reorganization of text matter into eight units. With addition of new topics, syllabi of many universities in this subject can be covered. Besides this, the book can also meet the requirements of M.Sc (Electronics), AMIETE, AMIE (Electronics) courses. Text matter is improved thoroughly. New topics like frequency effects in multistage amplifiers, amplifier circuit analysis, design of high frequency amplifiers, switching regulators, voltage multipliers, Uninterrupted Power Supplies (UPS), and Switchi

  17. Inrush Current Control Circuit

    Science.gov (United States)

    Cole, Steven W. (Inventor)

    2002-01-01

    An inrush current control circuit having an input terminal connected to a DC power supply and an output terminal connected to a load capacitor limits the inrush current that charges up the load capacitor during power up of a system. When the DC power supply applies a DC voltage to the input terminal, the inrush current control circuit produces a voltage ramp at the load capacitor instead of an abrupt DC voltage. The voltage ramp results in a constant low level current to charge up the load capacitor, greatly reducing the current drain on the DC power supply.

  18. Circuit design for reliability

    CERN Document Server

    Cao, Yu; Wirth, Gilson

    2015-01-01

    This book presents physical understanding, modeling and simulation, on-chip characterization, layout solutions, and design techniques that are effective to enhance the reliability of various circuit units.  The authors provide readers with techniques for state of the art and future technologies, ranging from technology modeling, fault detection and analysis, circuit hardening, and reliability management. Provides comprehensive review on various reliability mechanisms at sub-45nm nodes; Describes practical modeling and characterization techniques for reliability; Includes thorough presentation of robust design techniques for major VLSI design units; Promotes physical understanding with first-principle simulations.

  19. The effect of an advanced glycation end-product crosslink breaker and exercise training on vascular function in older individuals: a randomized factorial design trial.

    NARCIS (Netherlands)

    Oudegeest-Sander, M.H.; Olde Rikkert, M.G.M.; Smits, P.; Thijssen, D.H.J.; Dijk, A.P.J. van; Levine, B.D.; Hopman, M.T.E.

    2013-01-01

    Aging leads to accumulation of irreversible advanced glycation end-products (AGEs), contributing to vascular stiffening and endothelial dysfunction. When combined with the AGE-crosslink breaker Alagebrium, exercise training reverses cardiovascular aging in experimental animals. This study is the fir

  20. ESD analog circuits and design

    CERN Document Server

    Voldman, Steven H

    2014-01-01

    A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

  1. Unstable oscillators based hyperchaotic circuit

    DEFF Research Database (Denmark)

    Murali, K.; Tamasevicius, A.; G. Mykolaitis, A.;

    1999-01-01

    A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations in the circ...... in the circuit. The performance of the circuit is investigated by means of numerical integration of appropriate differential equations, PSPICE simulations, and hardware experiment.......A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations...

  2. Quantum secure circuit evaluation

    Institute of Scientific and Technical Information of China (English)

    CHEN Huanhuan; LI Bin; ZHUANG Zhenquan

    2004-01-01

    In order to solve the problem of classical secure circuit evaluation, this paper proposes a quantum approach. In this approach, the method of inserting redundant entangled particles and quantum signature has been employed to strengthen the security of the system. Theoretical analysis shows that our solution is secure against classical and quantum attacks.

  3. Superconducting Quantum Circuits

    NARCIS (Netherlands)

    Majer, J.B.

    2002-01-01

    This thesis describes a number of experiments with superconducting cir- cuits containing small Josephson junctions. The circuits are made out of aluminum islands which are interconnected with a very thin insulating alu- minum oxide layer. The connections form a Josephson junction. The current trough

  4. Bioluminescent bioreporter integrated circuit

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Michael L. (Knoxville, TN); Sayler, Gary S. (Blaine, TN); Paulus, Michael J. (Knoxville, TN)

    2000-01-01

    Disclosed are monolithic bioelectronic devices comprising a bioreporter and an OASIC. These bioluminescent bioreporter integrated circuit are useful in detecting substances such as pollutants, explosives, and heavy-metals residing in inhospitable areas such as groundwater, industrial process vessels, and battlefields. Also disclosed are methods and apparatus for environmental pollutant detection, oil exploration, drug discovery, industrial process control, and hazardous chemical monitoring.

  5. Resistor Combinations for Parallel Circuits.

    Science.gov (United States)

    McTernan, James P.

    1978-01-01

    To help simplify both teaching and learning of parallel circuits, a high school electricity/electronics teacher presents and illustrates the use of tables of values for parallel resistive circuits in which total resistances are whole numbers. (MF)

  6. The LMT circuit and SPICE

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamacevicius, Arunas

    2006-01-01

    The state equations of the LMT circuit are modeled as a dedicated analogue computer circuit and solved by means of PSpice. The nonlinear part of the system is studied. Problems with the PSpice program are presented....

  7. Electronic circuits and systems: A compilation. [including integrated circuits, logic circuits, varactor diode circuits, low pass filters, and optical equipment circuits

    Science.gov (United States)

    1975-01-01

    Technological information is presented electronic circuits and systems which have potential utility outside the aerospace community. Topics discussed include circuit components such as filters, converters, and integrators, circuits designed for use with specific equipment or systems, and circuits designed primarily for use with optical equipment or displays.

  8. Diode, transistor & fet circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Diode, Transistor and FET Circuits Manual is a handbook of circuits based on discrete semiconductor components such as diodes, transistors, and FETS. The book also includes diagrams and practical circuits. The book describes basic and special diode characteristics, heat wave-rectifier circuits, transformers, filter capacitors, and rectifier ratings. The text also presents practical applications of associated devices, for example, zeners, varicaps, photodiodes, or LEDs, as well as it describes bipolar transistor characteristics. The transistor can be used in three basic amplifier configuration

  9. Positive fractional linear electrical circuits

    Science.gov (United States)

    Kaczorek, Tadeusz

    2013-10-01

    The positive fractional linear systems and electrical circuits are addressed. New classes of fractional asymptotically stable and unstable electrical circuits are introduced. The Caputo and Riemann-Liouville definitions of fractional derivatives are used to analysis of the positive electrical circuits composed of resistors, capacitors, coils and voltage (current) sources. The positive fractional electrical and specially unstable different types electrical circuits are analyzed. Some open problems are formulated.

  10. Static Switching Dynamic Buffer Circuit

    OpenAIRE

    Pandey, A. K.; R. A. Mishra; R. K. Nagaria

    2013-01-01

    We proposed footless domino logic buffer circuit. It minimizes redundant switching at the dynamic and the output nodes. The proposed circuit avoids propagation of precharge pulse to the output node and allows the dynamic node which saves power consumption. Simulation is done using 0.18 µm CMOS technology. We have calculated the power consumption, delay, and power delay product of the proposed circuit and compared the results with the existing circuits for different logic function, loading co...

  11. Value Constraint and Monotone circuit

    OpenAIRE

    Kobayashi, Koji

    2012-01-01

    This paper talks about that monotone circuit is P-Complete. Decision problem that include P-Complete is mapping that classify input with a similar property. Therefore equivalence relation of input value is important for computation. But monotone circuit cannot compute the equivalence relation of the value because monotone circuit can compute only monotone function. Therefore, I make the value constraint explicitly in the input and monotone circuit can compute equivalence relation. As a result...

  12. Computational non-chemically equilibrium model on the current zero simulation in a model N2 circuit breaker under the free recovery condition

    Science.gov (United States)

    Sun, Hao; Tanaka, Yasunori; Tomita, Kentaro; Wu, Yi; Rong, Mingzhe; Uesugi, Yoshihiko; Ishijima, Tatsuo

    2016-02-01

    A non-chemically equilibrium (non-CE) model was established to investigate the N2 arc plasma in the decaying phase during the arc interruption, and was validated by comparison with the experimental results based on laser Thomson scattering. Unlike the conventional model assuming the local thermodynamic equilibrium (LTE), in this non-CE model, the magneto-hydro-dynamics (MHD) method was coupled with the reaction kinetics to obtain the time-dependent species compositions and properties. The current calculation took into account five species in hot gas and 22 chemical reactions in total. The time-dependent species compositions of hot N2 were derived from the mass conservation equation for each species, considering the effect of the convection, diffusion and the chemical reaction. The influence of the non-CE compositions on the arc decaying behavior was realized by updating the thermodynamic and transport properties at each iterative step. The results indicate that the non-CE model can result in the departure of the arc decaying behavior from the LTE model, because it alters the time evolution of the species composition and consequently changes the thermodynamic and transport properties. At the edge of the arc, the time evolutions of the species are dominant by both the diffusion and the chemical reactions while at the center of the arc they are mainly influenced by the chemical reactions. Generally, the non-CE effect can lead to the delay of all the particles’ variations, particularly the electron decay, so that the arc interruption performance will be reduced compared with that in the LTE model.

  13. Circuit breaker provides overcurrent and precise overvoltage protection%提供过电流和过电压保护的断路器

    Institute of Scientific and Technical Information of China (English)

    Anthony H Smith

    2007-01-01

    图1中的断路器仅需几个廉价的元件.即可对过电流和过电压故障状态进行反应。电路的核心是可调节的精密分路电压调节器D2,置在一只3引脚的封装中.提供了电压参考、比较器和集电极开路输出。

  14. 110 kV断路器和微机保护的联动校验%Interacting Calibration of 110 kV Circuit Breaker and Microprocessing Proteetion

    Institute of Scientific and Technical Information of China (English)

    陈志诚; 詹仲延

    2002-01-01

    简单分析送变电工程或技改项目选用微机保护后、一些启动方案仍按以前电磁继电器保护原理编写的不足,并对送电工程试运行启动方案的编写提出了修改建议。

  15. Design, Fabrication and pseudo Field Evaluation of a Sugar Beet Crust Breaker and Weeding Unit Equipped with an Infrared Sensor

    Directory of Open Access Journals (Sweden)

    E Chaligar

    2014-09-01

    Full Text Available In conventional cultivation of sugar beet the weeding and crust breaking are mostly performed manually. The objectives of this research were to design, fabricate and evaluate a soil crust breaker and weeding implement equipped with a detecting sensor. Each unit consisted of a distance detecting sensor and a hydro-motor for driving the blades and pneumatic valves for moving the blades. The hydro-motor was activated by the sensors. To avoid damaging the plants, a command signal was sent to the pneumatic valves to move the blades up and down and pass safely. Three configurations of cutting blades were considered which could be mounted to the crust breaker. The field evaluation was conducted with two tractor forward speeds (0.4 and 1 km h-1 and four plant-to-plant spacings within rows (20, 25, 30 and 40 cm all with three different blade shapes. For field evaluation split plot experiments arranged in a completely randomized block design with three replications. The number of plants damaged (evaluated only for four-lobe blades and size of broken crusts (evaluated for all blade shapes for various treatments were recorded and compared. The results of analysis indicated that the higher the inter-row spacing the lower the injury to the plant. The highest and the least damage to the plants occurred for within-row plant spacings of 20 and 40 cm, respectively. The forward speed was also significantly affected the percent of plant damaged. The forward speed of 1 km h-1 at 20 cm spacing had the most (59% and the speed of 0.40 km h-1 at 40 cm spacing had the least effect (3.3% on the percent of plant damage. The two-lobe blade could result in the maximum surface area broken.

  16. LC-Circuit Calorimetry

    CERN Document Server

    Bossen, Olaf

    2011-01-01

    We present a new type of calorimeter in which we couple an unknown heat capacity with the aid of Peltier elements to an electrical circuit. The use of an electrical inductance and an amplifier in the circuit allows us to achieve autonomous oscillations, and the measurement of the corresponding resonance frequency makes it possible to accurately measure the heat capacity with an intrinsic statistical error that decreases as ~t^{-3/2} with measuring time t, as opposed to a corresponding error ~t^{-1/2} in the conventional alternating current (a.c.) method to measure heat capacities. We have built a demonstration experiment to show the feasibility of the new technique, and we have tested it on a gadolinium sample at its transition to the ferromagnetic state.

  17. Engineering prokaryotic gene circuits

    OpenAIRE

    Michalodimitrakis, Konstantinos; Isalan, Mark

    2009-01-01

    Engineering of synthetic gene circuits is a rapidly growing discipline, currently dominated by prokaryotic transcription networks, which can be easily rearranged or rewired to give different output behaviours. In this review, we examine both a rational and a combinatorial design of such networks and discuss progress on using in vitro evolution techniques to obtain functional systems. Moving beyond pure transcription networks, more and more networks are being implemented at the level of RNA, t...

  18. Refractory Neuron Circuits

    OpenAIRE

    Sarpeshkar, Rahul; Watts, Lloyd; Mead, Carver

    1992-01-01

    Neural networks typically use an abstraction of the behaviour of a biological neuron, in which the continuously varying mean firing rate of the neuron is presumed to carry information about the neuron's time-varying state of excitation. However, the detailed timing of action potentials is known to be important in many biological systems. To build electronic models of such systems, one must have well-characterized neuron circuits that capture the essential behaviour of real neur...

  19. Electronic devices and circuits

    CERN Document Server

    Kishore, K Lal

    2008-01-01

    This book is written in a simple lucid Language along with derivation of equations and supported by numerous solved problems to help the student to understand the concepts clearly.Advances in Miniaturization of Electronic Systems by ever increasing packaging densities on Integrated Circuits has made it very essential for thorough Knowledge of the concepts, phenomenon, characteristics and behaviour of semiconductor Devices for students and professionals.

  20. Cartography of serotonergic circuits.

    Science.gov (United States)

    Sparta, Dennis R; Stuber, Garret D

    2014-08-01

    Serotonin is an essential neuromodulator, but the precise circuit connectivity that regulates serotonergic neurons has not been well defined. Using rabies virus tracing strategies Weissbourd et al. (2014) and Pollak Dorocic et al. (2014) in this issue of Neuron and Ogawa et al. (2014) in Cell Reports provide a comprehensive map of the inputs to serotonergic neurons, highlighting the complexity and diversity of potential upstream cellular regulators.

  1. PARTICLE BEAM TRACKING CIRCUIT

    Science.gov (United States)

    Anderson, O.A.

    1959-05-01

    >A particle-beam tracking and correcting circuit is described. Beam induction electrodes are placed on either side of the beam, and potentials induced by the beam are compared in a voltage comparator or discriminator. This comparison produces an error signal which modifies the fm curve at the voltage applied to the drift tube, thereby returning the orbit to the preferred position. The arrangement serves also to synchronize accelerating frequency and magnetic field growth. (T.R.H.)

  2. Fundamental Atomtronic Circuit Elements

    Science.gov (United States)

    Lee, Jeffrey; McIlvain, Brian; Lobb, Christopher; Hill, Wendell T., III

    2012-06-01

    Recent experiments with neutral superfluid gases have shown that it is possible to create atomtronic circuits analogous to existing superconducting circuits. The goals of these experiments are to create complex systems such as Josephson junctions. In addition, there are theoretical models for active atomtronic components analogous to diodes, transistors and oscillators. In order for any of these devices to function, an understanding of the more fundamental atomtronic elements is needed. Here we describe the first experimental realization of these more fundamental elements. We have created an atomtronic capacitor that is discharged through a resistance and inductance. We will discuss a theoretical description of the system that allows us to determine values for the capacitance, resistance and inductance. The resistance is shown to be analogous to the Sharvin resistance, and the inductance analogous to kinetic inductance in electronics. This atomtronic circuit is implemented with a thermal sample of laser cooled rubidium atoms. The atoms are confined using what we call free-space atom chips, a novel optical dipole trap produced using a generalized phase-contrast imaging technique. We will also discuss progress toward implementing this atomtronic system in a degenerate Bose gas.

  3. Scaled photographs of surf over the full range of breaker sizes on the north shore of Oahu and Jaws, Maui, Hawaiian Islands, January 1998 - May 2004 (NODC Accession 0001753)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digital surf photographs were scaled using surfers as height benchmarks to estimate the size of the breakers. Historical databases for surf height in Hawaii are...

  4. Changes to the shuttle circuits

    CERN Multimedia

    GS Department

    2011-01-01

    To fit with passengers expectation, there will be some changes to the shuttle circuits as from Monday 10 October. See details on http://cern.ch/ShuttleService (on line on 7 October). Circuit No. 5 is cancelled as circuit No. 1 also stops at Bldg. 33. In order to guarantee shorter travel times, circuit No. 1 will circulate on Meyrin site only and circuit No. 2, with departures from Bldg. 33 and 500, on Prévessin site only. Site Services Section

  5. Experimental determination of circuit equations

    CERN Document Server

    Shulman, Jason; Widjaja, Matthew; Gunaratne, Gemunu H

    2013-01-01

    Kirchhoff's laws offer a general, straightforward approach to circuit analysis. Unfortunately, use of the laws becomes impractical for all but the simplest of circuits. This work presents a novel method of analyzing direct current resistor circuits. It is based on an approach developed to model complex networks, making it appropriate for use on large, complicated circuits. It is unique in that it is not an analytic method. It is based on experiment, yet the approach produces the same circuit equations obtained by more traditional means.

  6. Power system with an integrated lubrication circuit

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, Brian D. (East Peoria, IL); Akasam, Sivaprasad (Peoria, IL); Algrain, Marcelo C. (Peoria, IL); Johnson, Kris W. (Washington, IL); Lane, William H. (Chillicothe, IL)

    2009-11-10

    A power system includes an engine having a first lubrication circuit and at least one auxiliary power unit having a second lubrication circuit. The first lubrication circuit is in fluid communication with the second lubrication circuit.

  7. Integrated coherent matter wave circuits

    International Nuclear Information System (INIS)

    An integrated coherent matter wave circuit is a single device, analogous to an integrated optical circuit, in which coherent de Broglie waves are created and then launched into waveguides where they can be switched, divided, recombined, and detected as they propagate. Applications of such circuits include guided atom interferometers, atomtronic circuits, and precisely controlled delivery of atoms. We report experiments demonstrating integrated circuits for guided coherent matter waves. The circuit elements are created with the painted potential technique, a form of time-averaged optical dipole potential in which a rapidly moving, tightly focused laser beam exerts forces on atoms through their electric polarizability. Moreover, the source of coherent matter waves is a Bose-Einstein condensate (BEC). Finally, we launch BECs into painted waveguides that guide them around bends and form switches, phase coherent beamsplitters, and closed circuits. These are the basic elements that are needed to engineer arbitrarily complex matter wave circuitry

  8. Memristor based startup circuit for self biased circuits

    Science.gov (United States)

    Das, Mangal; Singh, Amit Kumar; Rathi, Amit; Singhal, Sonal

    2016-04-01

    This paper presents the design of a Memristor based startup circuit for self biased circuits. Memristor has many advantages over conventional CMOS devices such as low leakage current at nanometer scale, easy to manufacture. In this work the switching characteristics of memristor is utilized. First the theoretical equations describing the switching behavior of memristor are investigated. To prove the switching capability of Memristor, a startup circuit based on memristor is proposed which uses series combination of Memristor and capacitor. Proposed circuit is compared with the previously reported MOSFET based startup circuits. Comparison of different circuits was done to validate the results. Simulation results show that memristor based circuit can attain on (I = 12.94 µA) to off state (I = 1 .2 µA) in 25 ns while the MOSFET based startup circuits take on (I = 14.19 µA) to off state (I = 1.4 µA) in more than 90 ns. The benefit comes in terms of area because the number of components used in the circuit are lesser than the conventional startup circuits.

  9. 一起220 kV GIS断路器放电故障分析与试验研究%Analysis and Experimental Research on Discharge Fault of 220 kV GIS Breaker

    Institute of Scientific and Technical Information of China (English)

    王流火; 林博楚; 吕鸿

    2015-01-01

    Due to large short-circuit energy and serious erosion of faulted equipments,it is unable to determine fault position and direct reasons when high voltage gas insulated metal enclosed switchgear and controlgear(GIS)happens large current short-circuit fault. In view of this,this paper analyzes and studies SF6 decomposition product of faulted GIS in some 220 kV substation and attachments on surface of faulted region by using energy disperse spectroscopy method. Combining disassem-bly return to depot and considering composition of breaker device,it analyzes reasons for causing the accident. Meanwhile, it studies impact on dielectric strength of GIS by ferruginous metallic particles and criticality of insulation deterioration in 220 kV GIS. The result indicates that the direct reason for the accident is ferruginous metallic particles in GIS breaker and the indirect reason is relax control on installation which makes GIS with defects. With the same voltage level,impact on die-lectric strength of GIS by metallic particles is more obvious,insulation deterioration is more severe and the GIS is liable to come up flashover.%高电压等级的气体绝缘金属封闭开关设备(gas insulated metal enclosed switchgear and controlgear,GIS)在发生大电流短路故障时,常常由于短路能量较大,故障设备烧蚀严重而无法确定故障位置和直接原因。针对此,采用扫描电子能谱(energy disperse spectroscopy,EDS)法对发生故障的220 kV某变电站 GIS 设备 SF6气体分解产物及故障区域表面附着物进行分析研究,结合返厂解体,同时考虑断路器设备原件的成分组成,分析了造成事故的原因。同时,在实体220 kV GIS内试验研究了铁质金属颗粒对 GIS绝缘强度的影响和绝缘劣化的危险程度。结果表明:GIS断路器内存在铁质金属异物是造成事故的直接原因,厂内安装控制不严造成的带缺陷出厂为间接原因;在同一电压等级下,金属异物越大对 GIS 的

  10. Photonic Integrated Circuits

    Science.gov (United States)

    Merritt, Scott; Krainak, Michael

    2016-01-01

    Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.

  11. Optoelectronics circuits manual

    CERN Document Server

    Marston, R M

    1999-01-01

    This manual is a useful single-volume guide specifically aimed at the practical design engineer, technician, and experimenter, as well as the electronics student and amateur. It deals with the subject in an easy to read, down to earth, and non-mathematical yet comprehensive manner, explaining the basic principles and characteristics of the best known devices, and presenting the reader with many practical applications and over 200 circuits. Most of the ICs and other devices used are inexpensive and readily available types, with universally recognised type numbers.The second edition

  12. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2007-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Each chapter ends with a set

  13. Electric circuits problem solver

    CERN Document Server

    REA, Editors of

    2012-01-01

    Each Problem Solver is an insightful and essential study and solution guide chock-full of clear, concise problem-solving gems. All your questions can be found in one convenient source from one of the most trusted names in reference solution guides. More useful, more practical, and more informative, these study aids are the best review books and textbook companions available. Nothing remotely as comprehensive or as helpful exists in their subject anywhere. Perfect for undergraduate and graduate studies.Here in this highly useful reference is the finest overview of electric circuits currently av

  14. Electronic logic circuits

    CERN Document Server

    Gibson, J

    2013-01-01

    Most branches of organizing utilize digital electronic systems. This book introduces the design of such systems using basic logic elements as the components. The material is presented in a straightforward manner suitable for students of electronic engineering and computer science. The book is also of use to engineers in related disciplines who require a clear introduction to logic circuits. This third edition has been revised to encompass the most recent advances in technology as well as the latest trends in components and notation. It includes a wide coverage of application specific integrate

  15. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2011-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Ea

  16. Linear integrated circuits

    CERN Document Server

    Carr, Joseph

    1996-01-01

    The linear IC market is large and growing, as is the demand for well trained technicians and engineers who understand how these devices work and how to apply them. Linear Integrated Circuits provides in-depth coverage of the devices and their operation, but not at the expense of practical applications in which linear devices figure prominently. This book is written for a wide readership from FE and first degree students, to hobbyists and professionals.Chapter 1 offers a general introduction that will provide students with the foundations of linear IC technology. From chapter 2 onwa

  17. Nano integrated circuit process

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yung Sup

    2004-02-15

    This book contains nine chapters, which are introduction of manufacture of semiconductor chip, oxidation such as Dry-oxidation, wet oxidation, oxidation model and oxide film, diffusion like diffusion process, diffusion equation, diffusion coefficient and diffusion system, ion implantation, including ion distribution, channeling, multiimplantation and masking and its system, sputtering such as CVD and PVD, lithography, wet etch and dry etch, interconnection and flattening like metal-silicon connection, silicide, multiple layer metal process and flattening, an integrated circuit process, including MOSFET and CMOS.

  18. Optically controllable molecular logic circuits

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Takahiro, E-mail: t-nishimura@ist.osaka-u.ac.jp; Fujii, Ryo; Ogura, Yusuke; Tanida, Jun [Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2015-07-06

    Molecular logic circuits represent a promising technology for observation and manipulation of biological systems at the molecular level. However, the implementation of molecular logic circuits for temporal and programmable operation remains challenging. In this paper, we demonstrate an optically controllable logic circuit that uses fluorescence resonance energy transfer (FRET) for signaling. The FRET-based signaling process is modulated by both molecular and optical inputs. Based on the distance dependence of FRET, the FRET pathways required to execute molecular logic operations are formed on a DNA nanostructure as a circuit based on its molecular inputs. In addition, the FRET pathways on the DNA nanostructure are controlled optically, using photoswitching fluorescent molecules to instruct the execution of the desired operation and the related timings. The behavior of the circuit can thus be controlled using external optical signals. As an example, a molecular logic circuit capable of executing two different logic operations was studied. The circuit contains functional DNAs and a DNA scaffold to construct two FRET routes for executing Input 1 AND Input 2 and Input 1 AND NOT Input 3 operations on molecular inputs. The circuit produced the correct outputs with all possible combinations of the inputs by following the light signals. Moreover, the operation execution timings were controlled based on light irradiation and the circuit responded to time-dependent inputs. The experimental results demonstrate that the circuit changes the output for the required operations following the input of temporal light signals.

  19. Optically controllable molecular logic circuits

    International Nuclear Information System (INIS)

    Molecular logic circuits represent a promising technology for observation and manipulation of biological systems at the molecular level. However, the implementation of molecular logic circuits for temporal and programmable operation remains challenging. In this paper, we demonstrate an optically controllable logic circuit that uses fluorescence resonance energy transfer (FRET) for signaling. The FRET-based signaling process is modulated by both molecular and optical inputs. Based on the distance dependence of FRET, the FRET pathways required to execute molecular logic operations are formed on a DNA nanostructure as a circuit based on its molecular inputs. In addition, the FRET pathways on the DNA nanostructure are controlled optically, using photoswitching fluorescent molecules to instruct the execution of the desired operation and the related timings. The behavior of the circuit can thus be controlled using external optical signals. As an example, a molecular logic circuit capable of executing two different logic operations was studied. The circuit contains functional DNAs and a DNA scaffold to construct two FRET routes for executing Input 1 AND Input 2 and Input 1 AND NOT Input 3 operations on molecular inputs. The circuit produced the correct outputs with all possible combinations of the inputs by following the light signals. Moreover, the operation execution timings were controlled based on light irradiation and the circuit responded to time-dependent inputs. The experimental results demonstrate that the circuit changes the output for the required operations following the input of temporal light signals

  20. Sequential circuit design for radiation hardened multiple voltage integrated circuits

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Lawrence T. (Phoenix, AZ); McIver, III, John K. (Albuquerque, NM)

    2009-11-24

    The present invention includes a radiation hardened sequential circuit, such as a bistable circuit, flip-flop or other suitable design that presents substantial immunity to ionizing radiation while simultaneously maintaining a low operating voltage. In one embodiment, the circuit includes a plurality of logic elements that operate on relatively low voltage, and a master and slave latches each having storage elements that operate on a relatively high voltage.

  1. Quasi-Linear Circuit

    Science.gov (United States)

    Bradley, William; Bird, Ross; Eldred, Dennis; Zook, Jon; Knowles, Gareth

    2013-01-01

    This work involved developing spacequalifiable switch mode DC/DC power supplies that improve performance with fewer components, and result in elimination of digital components and reduction in magnetics. This design is for missions where systems may be operating under extreme conditions, especially at elevated temperature levels from 200 to 300 degC. Prior art for radiation-tolerant DC/DC converters has been accomplished utilizing classical magnetic-based switch mode converter topologies; however, this requires specific shielding and component de-rating to meet the high-reliability specifications. It requires complex measurement and feedback components, and will not enable automatic re-optimization for larger changes in voltage supply or electrical loading condition. The innovation is a switch mode DC/DC power supply that eliminates the need for processors and most magnetics. It can provide a well-regulated voltage supply with a gain of 1:100 step-up to 8:1 step down, tolerating an up to 30% fluctuation of the voltage supply parameters. The circuit incorporates a ceramic core transformer in a manner that enables it to provide a well-regulated voltage output without use of any processor components or magnetic transformers. The circuit adjusts its internal parameters to re-optimize its performance for changes in supply voltage, environmental conditions, or electrical loading at the output

  2. Simple Cell Balance Circuit

    Science.gov (United States)

    Johnson, Steven D.; Byers, Jerry W.; Martin, James A.

    2012-01-01

    A method has been developed for continuous cell voltage balancing for rechargeable batteries (e.g. lithium ion batteries). A resistor divider chain is provided that generates a set of voltages representing the ideal cell voltage (the voltage of each cell should be as if the cells were perfectly balanced). An operational amplifier circuit with an added current buffer stage generates the ideal voltage with a very high degree of accuracy, using the concept of negative feedback. The ideal voltages are each connected to the corresponding cell through a current- limiting resistance. Over time, having the cell connected to the ideal voltage provides a balancing current that moves the cell voltage very close to that ideal level. In effect, it adjusts the current of each cell during charging, discharging, and standby periods to force the cell voltages to be equal to the ideal voltages generated by the resistor divider. The device also includes solid-state switches that disconnect the circuit from the battery so that it will not discharge the battery during storage. This solution requires relatively few parts and is, therefore, of lower cost and of increased reliability due to the fewer failure modes. Additionally, this design uses very little power. A preliminary model predicts a power usage of 0.18 W for an 8-cell battery. This approach is applicable to a wide range of battery capacities and voltages.

  3. 49 CFR 236.13 - Spring switch; selection of signal control circuits through circuit controller.

    Science.gov (United States)

    2010-10-01

    ... circuits through circuit controller. 236.13 Section 236.13 Transportation Other Regulations Relating to...; selection of signal control circuits through circuit controller. The control circuits of signals governing... circuit controller, or through the contacts of relay repeating the position of such circuit...

  4. Synthetic Biology: Integrated Gene Circuits

    OpenAIRE

    Nandagopal, Nagarajan; Michael B Elowitz

    2011-01-01

    A major goal of synthetic biology is to develop a deeper understanding of biological design principles from the bottom up, by building circuits and studying their behavior in cells. Investigators initially sought to design circuits “from scratch” that functioned as independently as possible from the underlying cellular system. More recently, researchers have begun to develop a new generation of synthetic circuits that integrate more closely with endogenous cellular processes. These approaches...

  5. Quantum Circuits with Mixed States

    OpenAIRE

    Aharonov, Dorit; Kitaev, Alexei; Nisan, Noam

    1998-01-01

    We define the model of quantum circuits with density matrices, where non-unitary gates are allowed. Measurements in the middle of the computation, noise and decoherence are implemented in a natural way in this model, which is shown to be equivalent in computational power to standard quantum circuits. The main result in this paper is a solution for the subroutine problem: The general function that a quantum circuit outputs is a probabilistic function, but using pure state language, such a func...

  6. Pharmacokinetics and RC Circuit Concepts

    Science.gov (United States)

    Cock, Mieke De; Janssen, Paul

    2013-11-01

    Most introductory physics courses include a chapter on RC circuits in which the differential equations for the charging and discharging of a capacitor are derived. A number of papers in this journal describe lab experiments dealing with the measurement of different parameters in such RC circuits. In this contribution, we report on a lab experiment we developed for students majoring in pharmacy, using RC circuits to simulate a pharmacokinetic process.

  7. Designing Parity Preserving Reversible Circuits

    OpenAIRE

    Paul, Goutam; Chattopadhyay, Anupam; Chandak, Chander

    2013-01-01

    Making a reversible circuit fault-tolerant is much more difficult than classical circuit and there have been only a few works in the area of parity-preserving reversible logic design. Moreover, all of these designs are ad hoc, based on some pre-defined parity preserving reversible gates as building blocks. In this paper, we for the first time propose a novel and systematic approach towards parity preserving reversible circuits design. We provide some related theoretical results and give two a...

  8. A Circuit to Demonstrate Phase Relationships in "RLC" Circuits

    Science.gov (United States)

    Sokol, P. E.; Warren, G.; Zheng, B.; Smith, P.

    2013-01-01

    We have developed a circuit to demonstrate the phase relationships between resistive and reactive elements in series "RLC" circuits. We utilize a differential amplifier to allow the phases of the three elements and the current to be simultaneously displayed on an inexpensive four channel oscilloscope. We have included a novel circuit…

  9. Design on the HCB Based on IGCT and Neural Network Current Detection

    OpenAIRE

    Yue Feng; Xiao-dong Wang; Yang Zhao; Yun-xia Jiang

    2013-01-01

    Nowaday,the traditional circuit breaker is which action slow, poor reliability, can not meet Large grid interconnection and flexible AC transmission requirements. To address those shortcomings of traditional circuit breaker,an idear is put forward that traditional mechanical circuit breaker combinates of power electronic switch-IGCT to build a new type of hybrid circuit breaker device (Hybrid Circuit Breaker shorted at HCB). Basing on natural converter circuit principles,when grid line failur...

  10. Memristor Circuits and Systems

    KAUST Repository

    Zidan, Mohammed A.

    2015-05-01

    Current CMOS-based technologies are facing design challenges related to the continuous scaling down of the minimum feature size, according to Moore’s law. Moreover, conventional computing architecture is no longer an effective way of fulfilling modern applications demands, such as big data analysis, pattern recognition, and vector processing. Therefore, there is an exigent need to shift to new technologies, at both the architecture and the device levels. Recently, memristor devices and structures attracted attention for being promising candidates for this job. Memristor device adds a new dimension for designing novel circuits and systems. In addition, high-density memristor-based crossbar is widely considered to be the essential element for future memory and bio-inspired computing systems. However, numerous challenges need to be addressed before the memristor genuinely replaces current memory and computing technologies, which is the motivation behind this research effort. In order to address the technology challenges, we begin by fabricating and modeling the memristor device. The devices fabricated at our local clean room enriched our understanding of the memristive phenomenon and enabled the experimental testing for our memristor-based circuits. Moreover, our proposed mathematical modeling for memristor behavior is an essential element for the theoretical circuit design stage. Designing and addressing the challenges of memristor systems with practical complexity, however, requires an extra step, which takes the form of a reliable and modular simulation platform. We, therefore, built a new simulation platform for the resistive crossbar, which can simulate realistic size arrays filled with real memory data. In addition, this simulation platform includes various crossbar nonidealities in order to obtain accurate simulation results. Consequently, we were able to address the significant challenges facing the high density memristor crossbar, as the building block for

  11. A dishwasher for circuits

    CERN Multimedia

    Rosaria Marraffino

    2014-01-01

    You have always been told that electronic devices fear water. However, at the Surface Mount Devices (SMD) Workshop here at CERN all the electronic assemblies are cleaned with a machine that looks like a… dishwasher.   The circuit dishwasher. Credit: Clara Nellist.  If you think the image above shows a dishwasher, you wouldn’t be completely wrong. Apart from the fact that the whole pumping system and the case itself are made entirely from stainless steel and chemical resistant materials, and the fact that it washes electrical boards instead of dishes… it works exactly like a dishwasher. It’s a professional machine (mainly used in the pharmaceutical industry) designed to clean everything that can be washed with a water-based chemical soap. This type of treatment increases the lifetime of the electronic boards and therefore the LHC's reliability by preventing corrosion problems in the severe radiation and ozone environment of the LHC tunn...

  12. Basic electronic circuits

    CERN Document Server

    Buckley, P M

    1980-01-01

    In the past, the teaching of electricity and electronics has more often than not been carried out from a theoretical and often highly academic standpoint. Fundamentals and basic concepts have often been presented with no indication of their practical appli­ cations, and all too frequently they have been illustrated by artificially contrived laboratory experiments bearing little relationship to the outside world. The course comes in the form of fourteen fairly open-ended constructional experiments or projects. Each experiment has associated with it a construction exercise and an explanation. The basic idea behind this dual presentation is that the student can embark on each circuit following only the briefest possible instructions and that an open-ended approach is thereby not prejudiced by an initial lengthy encounter with the theory behind the project; this being a sure way to dampen enthusiasm at the outset. As the investigation progresses, questions inevitably arise. Descriptions of the phenomena encounte...

  13. Modeling cortical circuits.

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, Brandon Robinson; Rothganger, Fredrick H.; Verzi, Stephen J.; Xavier, Patrick Gordon

    2010-09-01

    The neocortex is perhaps the highest region of the human brain, where audio and visual perception takes place along with many important cognitive functions. An important research goal is to describe the mechanisms implemented by the neocortex. There is an apparent regularity in the structure of the neocortex [Brodmann 1909, Mountcastle 1957] which may help simplify this task. The work reported here addresses the problem of how to describe the putative repeated units ('cortical circuits') in a manner that is easily understood and manipulated, with the long-term goal of developing a mathematical and algorithmic description of their function. The approach is to reduce each algorithm to an enhanced perceptron-like structure and describe its computation using difference equations. We organize this algorithmic processing into larger structures based on physiological observations, and implement key modeling concepts in software which runs on parallel computing hardware.

  14. Closed Circuit Videoinstallationen

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    be seen with only insignificant qualification as a specific characteristic of the medium. The closed-circuit video installations based on it represent the attest field of experiment for the assumptions on art and the theory and history of the medium that it might lead one make. In recent years......, theoretical debate on the medium has diagnosed with some precision where the electronic video image stands between analogue and digital codes, or again, between media representation and presentation; but that position has hardly ever been subjected to examination against the pertinent examples. An art...... of video as well as the latest digital art forms, can then be examined with the aid of such results and elucidated in historical terms. The prospect at least, of a gradual introduction of the electronic arts into the art history syllabus will be brought a deal closer thanks to such individual...

  15. Diamond Integrated Optomechanical Circuits

    CERN Document Server

    Rath, Patrik; Nebel, Christoph; Wild, Christoph; Pernice, Wolfram H P

    2013-01-01

    Diamond offers unique material advantages for the realization of micro- and nanomechanical resonators due to its high Young's modulus, compatibility with harsh environments and superior thermal properties. At the same time, the wide electronic bandgap of 5.45eV makes diamond a suitable material for integrated optics because of broadband transparency and the absence of free-carrier absorption commonly encountered in silicon photonics. Here we take advantage of both to engineer full-scale optomechanical circuits in diamond thin films. We show that polycrystalline diamond films fabricated by chemical vapour deposition provide a convenient waferscale substrate for the realization of high quality nanophotonic devices. Using free-standing nanomechanical resonators embedded in on-chip Mach-Zehnder interferometers, we demonstrate efficient optomechanical transduction via gradient optical forces. Fabricated diamond resonators reproducibly show high mechanical quality factors up to 11,200. Our low cost, wideband, carri...

  16. VLSI circuits implementing computational models of neocortical circuits.

    Science.gov (United States)

    Wijekoon, Jayawan H B; Dudek, Piotr

    2012-09-15

    This paper overviews the design and implementation of three neuromorphic integrated circuits developed for the COLAMN ("Novel Computing Architecture for Cognitive Systems based on the Laminar Microcircuitry of the Neocortex") project. The circuits are implemented in a standard 0.35 μm CMOS technology and include spiking and bursting neuron models, and synapses with short-term (facilitating/depressing) and long-term (STDP and dopamine-modulated STDP) dynamics. They enable execution of complex nonlinear models in accelerated-time, as compared with biology, and with low power consumption. The neural dynamics are implemented using analogue circuit techniques, with digital asynchronous event-based input and output. The circuits provide configurable hardware blocks that can be used to simulate a variety of neural networks. The paper presents experimental results obtained from the fabricated devices, and discusses the advantages and disadvantages of the analogue circuit approach to computational neural modelling. PMID:22342970

  17. Pharmacokinetics and "RC" Circuit Concepts

    Science.gov (United States)

    De Cock, Mieke; Janssen, Paul

    2013-01-01

    Most introductory physics courses include a chapter on "RC" circuits in which the differential equations for the charging and discharging of a capacitor are derived. A number of papers in this journal describe lab experiments dealing with the measurement of different parameters in such "RC" circuits. In this contribution, we…

  18. Enhancement of Linear Circuit Program

    DEFF Research Database (Denmark)

    Gaunholt, Hans; Dabu, Mihaela; Beldiman, Octavian

    1996-01-01

    In this report a preliminary user friendly interface has been added to the LCP2 program making it possible to describe an electronic circuit by actually drawing the circuit on the screen. Component values and other options and parameters can easily be set by the aid of the interface. The interface...

  19. Demonstrations with an "LCR" Circuit

    Science.gov (United States)

    Kraftmakher, Yaakov

    2011-01-01

    The "LCR" circuit is an important topic in the course of electricity and magnetism. Papers in this field consider mainly the forced oscillations and resonance. Our aim is to show how to demonstrate the free and self-excited oscillations in an "LCR" circuit. (Contains 4 figures.)

  20. Logic Circuit Design Selected Methods

    CERN Document Server

    Vingron, Shimon P

    2012-01-01

        In three main divisions the  book covers combinational circuits, latches, and asynchronous sequential circuits. Combinational circuits have  no memorising ability, while sequential circuits have such an ability to various degrees. Latches are the simplest sequential circuits, ones with the shortest memory. The presentation is decidedly non-standard.         The design of combinational circuits is discussed in an orthodox manner using normal forms and in an unorthodox manner using set-theoretical evaluation formulas relying heavily on Karnaugh maps. The latter approach allows for a new design technique called composition.          Latches are covered very extensively. Their memory functions are expressed mathematically in a time-independent manner allowing the use of (normal, non-temporal) Boolean logic in their calculation. The theory of latches is then used as the basis for calculating asynchronous circuits.         Asynchronous circuits are specified in a tree-representation, eac...

  1. 49 CFR 236.728 - Circuit, trap.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, trap. 236.728 Section 236.728... Circuit, trap. A term applied to a circuit used where it is desirable to provide a track circuit but where it is impracticable to maintain a track circuit....

  2. Variational integrators for electric circuits

    CERN Document Server

    Ober-Blöbaum, Sina; Cheng, Mulin; Owhadi, Houman; Marsden, Jerrold E

    2011-01-01

    In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electrical circuit, one is faced with three special situations: 1. The system involves external (control) forcing through external (controlled) voltage sources and resistors. 2. The system is constrained via the Kirchhoff current (KCL) and voltage laws (KVL). 3. The Lagrangian is degenerate. Based on a geometric setting, an appropriate variational formulation is presented to model the circuit from which the equations of motion are derived. A time-discrete variational formulation provides an iteration scheme for the simulation of the electric circuit. Dependent on the discretization, the intrinsic degeneracy of the system can be canceled for the discrete variational scheme. In this way, a variational integrator is constructed that gains several advantages compared to standard integration tools for circuits; in particular, a comparison to BDF methods ...

  3. Electronic design with integrated circuits

    Science.gov (United States)

    Comer, D. J.

    The book is concerned with the application of integrated circuits and presents the material actually needed by the system designer to do an effective job. The operational amplifier (op amp) is discussed, taking into account the electronic amplifier, the basic op amp, the practical op amp, analog applications, and digital applications. Digital components are considered along with combinational logic, digital subsystems, the microprocessor, special circuits, communications, and integrated circuit building blocks. Attention is given to logic gates, logic families, multivibrators, the digital computer, digital methods, communicating with a computer, computer organization, register and timing circuits for data transfer, arithmetic circuits, memories, the microprocessor chip, the control unit, communicating with the microprocessor, examples of microprocessor architecture, programming a microprocessor, the voltage-controlled oscillator, the phase-locked loop, analog-to-digital conversion, amplitude modulation, frequency modulation, pulse and digital transmission, the semiconductor diode, the bipolar transistor, and the field-effect transistor.

  4. Demultiplexer circuit for neural stimulation

    Science.gov (United States)

    Wessendorf, Kurt O; Okandan, Murat; Pearson, Sean

    2012-10-09

    A demultiplexer circuit is disclosed which can be used with a conventional neural stimulator to extend the number of electrodes which can be activated. The demultiplexer circuit, which is formed on a semiconductor substrate containing a power supply that provides all the dc electrical power for operation of the circuit, includes digital latches that receive and store addressing information from the neural stimulator one bit at a time. This addressing information is used to program one or more 1:2.sup.N demultiplexers in the demultiplexer circuit which then route neural stimulation signals from the neural stimulator to an electrode array which is connected to the outputs of the 1:2.sup.N demultiplexer. The demultiplexer circuit allows the number of individual electrodes in the electrode array to be increased by a factor of 2.sup.N with N generally being in a range of 2-4.

  5. Cause analysis of circuit breaker tripping caused by AC power flowing into DC circuit%交流电源串入直流电源回路导致断路器跳合闸原因分析

    Institute of Scientific and Technical Information of China (English)

    赵永生; 庄洪波

    2010-01-01

    介绍2起多台断路器同时跳闸或合闸的典型事故,通过现场试验验证和分析,证明当交流电源串入直流电源回路中,可能引起多台断路器跳闸或合闸,并提出防范措施.

  6. Performance analysis of electrical circuits /PANE/

    Science.gov (United States)

    Johnson, K. L.; Steinberg, L. L.

    1968-01-01

    Automated statistical and worst case computer program has been designed to perform dc and ac steady circuit analyses. The program determines the worst case circuit performance by solving circuit equations.

  7. Global optimization of digital circuits

    Science.gov (United States)

    Flandera, Richard

    1991-12-01

    This thesis was divided into two tasks. The first task involved developing a parser which could translate a behavioral specification in Very High-Speed Integrated Circuits (VHSIC) Hardware Description Language (VHDL) into the format used by an existing digital circuit optimization tool, Boolean Reasoning In Scheme (BORIS). Since this tool is written in Scheme, a dialect of Lisp, the parser was also written in Scheme. The parser was implemented is Artez's modification of Earley's Algorithm. Additionally, a VHDL tokenizer was implemented in Scheme and a portion of the VHDL grammar was converted into the format which the parser uses. The second task was the incorporation of intermediate functions into BORIS. The existing BORIS contains a recursive optimization system that optimizes digital circuits by using circuit outputs as inputs into other circuits. Intermediate functions provide a greater selection of functions to be used as circuits inputs. Using both intermediate functions and output functions, the costs of the circuits in the test set were reduced by 43 percent. This is a 10 percent reduction when compared to the existing recursive optimization system. Incorporating intermediate functions into BORIS required the development of an intermediate-function generator and a set of control methods to keep the computation time from increasing exponentially.

  8. Spectral Purity Enhancement via Polyphase Multipath Circuits

    OpenAIRE

    Mensink, Eisse; Klumperink, Eric; Nauta, Bram

    2004-01-01

    The central question of this paper is: can we enhance the spectral purity of nonlinear circuits by using polyphase multipath circuits? The basic idea behind polyphase multipath circuits is to split the nonlinear circuits into two or more paths and exploit phase differences between these paths to cancel undesired distortion products. It turns out that it is very well possible to use polyphase multipath circuits to cancel distortion products produced by a nonlinear circuit. Unfortunately, there...

  9. Determining Covers in Combinational Circuits

    Directory of Open Access Journals (Sweden)

    Ljubomir Cvetkovic

    2011-05-01

    Full Text Available In this paper we propose a procedure for determining 0- or 1-cover of an arbitrary line in a combinational circuit. When determining a cover we do not need Boolean expression for the line; only the circuit structure is used. Within the proposed procedure we use the tools of the cube theory, in particular, some operations defined on cubes. The procedure can be applied for determining 0- and 1- covers of output lines in programmable logic devices. Basically, this procedure is a method for the analysis of a combinational circuit.

  10. The Maplin electronic circuits handbook

    CERN Document Server

    Tooley, Michael

    2015-01-01

    The Maplin Electronic Circuits Handbook provides pertinent data, formula, explanation, practical guidance, theory and practical guidance in the design, testing, and construction of electronic circuits. This book discusses the developments in electronics technology techniques.Organized into 11 chapters, this book begins with an overview of the common types of passive component. This text then provides the reader with sufficient information to make a correct selection of passive components for use in the circuits. Other chapters consider the various types of the most commonly used semiconductor

  11. Secure integrated circuits and systems

    CERN Document Server

    Verbauwhede, Ingrid MR

    2010-01-01

    On any advanced integrated circuit or 'system-on-chip' there is a need for security. In many applications the actual implementation has become the weakest link in security rather than the algorithms or protocols. The purpose of the book is to give the integrated circuits and systems designer an insight into the basics of security and cryptography from the implementation point of view. As a designer of integrated circuits and systems it is important to know both the state-of-the-art attacks as well as the countermeasures. Optimizing for security is different from optimizations for speed, area,

  12. 某型动车组空气压缩机保护电路优化设计探讨%Discussion of the Optimization Design of the Protective Electrical Circuit in the Air Compressor for a Certain Type of Multiple Units

    Institute of Scientific and Technical Information of China (English)

    于建功

    2012-01-01

    In view of the bur.ning damage of the driving motor and power supply Circuit breaker in the air compressor occurred in testing of a certain type of multiple units, the causes are analyzed, and the suggestion for design optimization is given.%针对某型动车组在试验过程中发生的空气压缩机驱动电机和电源断路器烧损的问题进行了原因分析,并提出了优化设计建议.

  13. CADAT integrated circuit mask analysis

    Science.gov (United States)

    1981-01-01

    CADAT System Mask Analysis Program (MAPS2) is automated software tool for analyzing integrated-circuit mask design. Included in MAPS2 functions are artwork verification, device identification, nodal analysis, capacitance calculation, and logic equation generation.

  14. Discharge quenching circuit for counters

    International Nuclear Information System (INIS)

    A circuit for quenching discharges in gas-discharge detectors with working voltage of 3-5 kV based on transistors operating in the avalanche mode is described. The quenching circuit consists of a coordinating emitter follower, amplifier-shaper for avalanche key cascade control which changes potential on the counter electrodes and a shaper of discharge quenching duration. The emitter follower is assembled according to a widely used flowsheet with two transistors. The circuit permits to obtain a rectangular quenching pulse with front of 100 ns and an amplitude of up to 3.2 kV at duration of 500 μm-8 ms. Application of the quenching circuit described permits to obtain countering characteristics with the slope less than or equal to 0.02%/V and plateau extent greater than or equal to 300 V

  15. Wireless communications circuits and systems

    CERN Document Server

    Sun, Yichuang

    2004-01-01

    This new book examines integrated circuits, systems and transceivers for wireless and mobile communications. It covers the most recent developments in key RF, IF, analogue, mixed-signal components and single-chip transceivers in CMOS technology.

  16. Extensional Uniformity for Boolean Circuits

    CERN Document Server

    McKenzie, Pierre; Vollmer, Heribert

    2008-01-01

    Imposing an extensional uniformity condition on a non-uniform circuit complexity class C means simply intersecting C with a uniform class L. By contrast, the usual intensional uniformity conditions require that a resource-bounded machine be able to exhibit the circuits in the circuit family defining C. We say that (C,L) has the "Uniformity Duality Property" if the extensionally uniform class C \\cap L can be captured intensionally by means of adding so-called "L-numerical predicates" to the first-order descriptive complexity apparatus describing the connection language of the circuit family defining C. This paper exhibits positive instances and negative instances of the Uniformity Duality Property.

  17. Circuit design on plastic foils

    CERN Document Server

    Raiteri, Daniele; Roermund, Arthur H M

    2015-01-01

    This book illustrates a variety of circuit designs on plastic foils and provides all the information needed to undertake successful designs in large-area electronics.  The authors demonstrate architectural, circuit, layout, and device solutions and explain the reasons and the creative process behind each. Readers will learn how to keep under control large-area technologies and achieve robust, reliable circuit designs that can face the challenges imposed by low-cost low-temperature high-throughput manufacturing.   • Discusses implications of problems associated with large-area electronics and compares them to standard silicon; • Provides the basis for understanding physics and modeling of disordered material; • Includes guidelines to quickly setup the basic CAD tools enabling efficient and reliable designs; • Illustrates practical solutions to cope with hard/soft faults, variability, mismatch, aging and bias stress at architecture, circuit, layout, and device levels.

  18. Practical circuits with Physarum Wires

    OpenAIRE

    Whiting, James G. H.; Mayne, Richard; Moody, Nadine; Costello, Ben de Lacy; Adamatzky, Andrew

    2015-01-01

    Purpose: Protoplasmic tubes of Physarum polycephalum, also know as Physarum Wires (PW), have been previously suggested as novel bio- electronic components. Until recently, practical examples of electronic circuits using PWs have been limited. These PWs have been shown to be self repairing, offering significant advantage over traditional electronic components. This article documents work performed to produce practical circuits using PWs. Method: We have demonstrated through manufacture and tes...

  19. Receiver Gain Modulation Circuit

    Science.gov (United States)

    Jones, Hollis; Racette, Paul; Walker, David; Gu, Dazhen

    2011-01-01

    A receiver gain modulation circuit (RGMC) was developed that modulates the power gain of the output of a radiometer receiver with a test signal. As the radiometer receiver switches between calibration noise references, the test signal is mixed with the calibrated noise and thus produces an ensemble set of measurements from which ensemble statistical analysis can be used to extract statistical information about the test signal. The RGMC is an enabling technology of the ensemble detector. As a key component for achieving ensemble detection and analysis, the RGMC has broad aeronautical and space applications. The RGMC can be used to test and develop new calibration algorithms, for example, to detect gain anomalies, and/or correct for slow drifts that affect climate-quality measurements over an accelerated time scale. A generalized approach to analyzing radiometer system designs yields a mathematical treatment of noise reference measurements in calibration algorithms. By treating the measurements from the different noise references as ensemble samples of the receiver state, i.e. receiver gain, a quantitative description of the non-stationary properties of the underlying receiver fluctuations can be derived. Excellent agreement has been obtained between model calculations and radiometric measurements. The mathematical formulation is equivalent to modulating the gain of a stable receiver with an externally generated signal and is the basis for ensemble detection and analysis (EDA). The concept of generating ensemble data sets using an ensemble detector is similar to the ensemble data sets generated as part of ensemble empirical mode decomposition (EEMD) with exception of a key distinguishing factor. EEMD adds noise to the signal under study whereas EDA mixes the signal with calibrated noise. It is mixing with calibrated noise that permits the measurement of temporal-functional variability of uncertainty in the underlying process. The RGMC permits the evaluation of EDA by

  20. Difference-Equation/Flow-Graph Circuit Analysis

    Science.gov (United States)

    Mcvey, I. M.

    1988-01-01

    Numerical technique enables rapid, approximate analyses of electronic circuits containing linear and nonlinear elements. Practiced in variety of computer languages on large and small computers; for circuits simple enough, programmable hand calculators used. Although some combinations of circuit elements make numerical solutions diverge, enables quick identification of divergence and correction of circuit models to make solutions converge.

  1. Multi-Layer E-Textile Circuits

    Science.gov (United States)

    Dunne, Lucy E.; Bibeau, Kaila; Mulligan, Lucie; Frith, Ashton; Simon, Cory

    2012-01-01

    Stitched e-textile circuits facilitate wearable, flexible, comfortable wearable technology. However, while stitched methods of e-textile circuits are common, multi-layer circuit creation remains a challenge. Here, we present methods of stitched multi-layer circuit creation using accessible tools and techniques.

  2. Tunable circuit for tunable capacitor devices

    Science.gov (United States)

    Rivkina, Tatiana; Ginley, David S.

    2006-09-19

    A tunable circuit (10) for a capacitively tunable capacitor device (12) is provided. The tunable circuit (10) comprises a tunable circuit element (14) and a non-tunable dielectric element (16) coupled to the tunable circuit element (16). A tunable capacitor device (12) and a method for increasing the figure of merit in a tunable capacitor device (12) are also provided.

  3. Comparison between four piezoelectric energy harvesting circuits

    Institute of Scientific and Technical Information of China (English)

    Jinhao QIU; Hao JIANG; Hongli JI; Kongjun ZHU

    2009-01-01

    This paper investigates and compares the efficiencies of four different interfaces for vibration-based energy harvesting systems. Among those four circuits, two circuits adopt the synchronous switching technique, in which the circuit is switched synchronously with the vibration. In this study, a simple source-less trigger circuit used to control the synchronized switch is proposed and two interface circuits of energy harvesting systems are designed based on the trigger circuit. To validate the effectiveness of the proposed circuits, an experimental system was established and the power harvested by those circuits from a vibration beam was measured. Experimental results show that the two new circuits can increase the harvested power by factors 2.6 and 7, respectively, without consuming extra power in the circuits.

  4. Distortion Cancellation via Polyphase Multipath Circuits

    OpenAIRE

    Mensink, Eisse; Klumperink, Eric A.M.; Nauta, Bram

    2004-01-01

    The central question of this paper is: can we enhance the spectral purity of nonlinear circuits with the help of polyphase multipath circuits. Polyphase multipath circuits are circuits with two or more paths that exploit phase differences between the paths to cancel unwanted signals. It turns out that it is very well possible to cancel distortion products produced by a nonlinear circuit. Unfortunately, there are also some spectral components that cannot be cancelled with the polyphase multipa...

  5. Instrumentation and test gear circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Instrumentation and Test Gear Circuits Manual provides diagrams, graphs, tables, and discussions of several types of practical circuits. The practical circuits covered in this book include attenuators, bridges, scope trace doublers, timebases, and digital frequency meters. Chapter 1 discusses the basic instrumentation and test gear principles. Chapter 2 deals with the design of passive attenuators, and Chapter 3 with passive and active filter circuits. The subsequent chapters tackle 'bridge' circuits, analogue and digital metering techniques and circuitry, signal and waveform generation, and p

  6. A New Method for Constructing Circuit Codes

    OpenAIRE

    Byrnes, Kevin M.

    2016-01-01

    Circuit codes are constructed from induced cycles in the graph of the $n$ dimensional hypercube. They are both theoretically and practically important, as circuit codes can be used as error correcting codes. When constructing circuit codes, the length of the cycle determines its accuracy and a parameter called the spread determines how many errors it can detect. We present a new method for constructing a circuit code of spread $k+1$ from a circuit code of spread $k$. This method leads to reco...

  7. Introduction to lethal circuit transformations

    Science.gov (United States)

    Fišer, Petr; Schmidt, Jan

    2015-12-01

    Logic optimization is a process that takes a logic circuit description (Boolean network) as an input and tries to refine it, to reduce its size and/or depth. An ideal optimization process should be able to devise an optimum implementation of a network in a reasonable time, given any circuit structure at the input. However, there are cases where it completely fails to produce even near-optimum solutions. Such cases are typically induced by non-standard circuit structure modifications. Surprisingly enough, such deviated structures are frequently present in standard benchmark sets too. We may only wonder whether it is an intention of the benchmarks creators, or just an unlucky coincidence. Even though synthesis tools should be primarily well suited for practical circuits, there is no guarantee that, e.g., a higher-level synthesis process will not generate such unlucky structures. Here we present examples of circuit transformations that lead to failure of most of state-of-the-art logic synthesis and optimization processes, both academic and commercial, and suggest actions to mitigate the disturbing effects.

  8. Improved Simulation of Stabilizer Circuits

    CERN Document Server

    Aaronson, S; Aaronson, Scott; Gottesman, Daniel

    2004-01-01

    The Gottesman-Knill theorem says that a stabilizer circuit -- that is, a quantum circuit consisting solely of CNOT, Hadamard, and phase gates -- can be simulated efficiently on a classical computer. This paper improves that theorem in several directions. * By removing the need for Gaussian elimination, we make the simulation algorithm much faster at the cost of a factor-2 increase in the number of bits needed to represent a state. We have implemented the improved algorithm in a freely-available program called CHP (CNOT-Hadamard-Phase), which can handle thousands of qubits easily. * We show that the problem of simulating stabilizer circuits is complete for the classical complexity class ParityL, which means that stabilizer circuits are probably not even universal for classical computation. * We give efficient algorithms for computing the inner product between two stabilizer states, putting any n-qubit stabilizer circuit into a "canonical form" that requires at most O(n^2/log n) gates, and other useful tasks. *...

  9. 30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

    Science.gov (United States)

    2010-07-01

    ... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection. Automatic... electric equipment and circuits against short circuit and overloads. Three-phase motors on all electric... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload...

  10. 49 CFR 236.5 - Design of control circuits on closed circuit principle.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Design of control circuits on closed circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on closed circuit principle. All control circuits the functioning of which affects safety of train...

  11. 络筒机智能防叠装置的研究%Sudy on intelligent ribboning breaker of a winder

    Institute of Scientific and Technical Information of China (English)

    王元昌; 薛卫; 肖荣

    2002-01-01

    现有的络筒机防叠装置不管有无重叠发生都按预设的周期作防叠动作,所以有多余的动作,又不能完全消除重叠.针对这一问题,笔者开发了智能防叠装置.这一装置在发生重叠时做防叠动作,否则络简机保持满速度运转.文中导出了纱圈重叠的条件,设计了微机的软件与硬件系统.%The ribboning breaker in a winder available does the anti-ribboning motion according to the preset-up period whatever ribboing or not. So there are motions to be unnecessary, moreover, it cannot eliminate the ribboning completely. Intelligent ribboning breaker does an anti-ribboning motion when produced ribboning, otherwise the winder keeps running fully. In this paper, the yarn loops ribboning conditions are deduced. Each spindle is controlled by a single-chip microcomputer to determine whether the yarn loop or not according to the ribboning conditions every yarn traverse to and fro, and to control the motor driving the grooved drum to change its rotational speed. The hardware and software design are written.

  12. Circuit model of Rimfire switch

    International Nuclear Information System (INIS)

    A cascade gaps circuit model for Rimfire switch has been developed. The circuit model includes all stray capacitances and spark channel on-state conduction characteristics. It can not only describe the behavior of Rimfire switch, but also allow analysis of the time varying voltage and current at each part of the switch, describing the internal characters of the switch. PSpice was used to implement the cascade gaps circuit model and simulate a 700 kV Rimfire switch. The simulation shows that, the voltage of the whole switch will be higher than 700 kV when the laser triggered section has broken down but all cascade gaps keep dielectric, and the voltage of all gaps attenuates with high frequency oscillation. (authors)

  13. Additive Manufacturing of Hybrid Circuits

    Science.gov (United States)

    Sarobol, Pylin; Cook, Adam; Clem, Paul G.; Keicher, David; Hirschfeld, Deidre; Hall, Aaron C.; Bell, Nelson S.

    2016-07-01

    There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects. Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. Finally, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.

  14. Vertically Integrated Circuits at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Deptuch, Grzegorz; Demarteau, Marcel; Hoff, James; Lipton, Ronald; Shenai, Alpana; Trimpl, Marcel; Yarema, Raymond; Zimmerman, Tom; /Fermilab

    2009-01-01

    The exploration of the vertically integrated circuits, also commonly known as 3D-IC technology, for applications in radiation detection started at Fermilab in 2006. This paper examines the opportunities that vertical integration offers by looking at various 3D designs that have been completed by Fermilab. The emphasis is on opportunities that are presented by through silicon vias (TSV), wafer and circuit thinning and finally fusion bonding techniques to replace conventional bump bonding. Early work by Fermilab has led to an international consortium for the development of 3D-IC circuits for High Energy Physics. The consortium has submitted over 25 different designs for the Fermilab organized MPW run organized for the first time.

  15. Nuclear sensor signal processing circuit

    Science.gov (United States)

    Kallenbach, Gene A.; Noda, Frank T.; Mitchell, Dean J.; Etzkin, Joshua L.

    2007-02-20

    An apparatus and method are disclosed for a compact and temperature-insensitive nuclear sensor that can be calibrated with a non-hazardous radioactive sample. The nuclear sensor includes a gamma ray sensor that generates tail pulses from radioactive samples. An analog conditioning circuit conditions the tail-pulse signals from the gamma ray sensor, and a tail-pulse simulator circuit generates a plurality of simulated tail-pulse signals. A computer system processes the tail pulses from the gamma ray sensor and the simulated tail pulses from the tail-pulse simulator circuit. The nuclear sensor is calibrated under the control of the computer. The offset is adjusted using the simulated tail pulses. Since the offset is set to zero or near zero, the sensor gain can be adjusted with a non-hazardous radioactive source such as, for example, naturally occurring radiation and potassium chloride.

  16. Fault Testing for Reversible Circuits

    CERN Document Server

    Patel, K N; Markov, I L; Patel, Ketan N.; Hayes, John P.; Markov, Igor L.

    2004-01-01

    Applications of reversible circuits can be found in the fields of low-power computation, cryptography, communications, digital signal processing, and the emerging field of quantum computation. Furthermore, prototype circuits for low-power applications are already being fabricated in CMOS. Regardless of the eventual technology adopted, testing is sure to be an important component in any robust implementation. We consider the test set generation problem. Reversibility affects the testing problem in fundamental ways, making it significantly simpler than for the irreversible case. For example, we show that any test set that detects all single stuck-at faults in a reversible circuit also detects all multiple stuck-at faults. We present efficient test set constructions for the standard stuck-at fault model as well as the usually intractable cell-fault model. We also give a practical test set generation algorithm, based on an integer linear programming formulation, that yields test sets approximately half the size o...

  17. Design automation for integrated circuits

    Science.gov (United States)

    Newell, S. B.; de Geus, A. J.; Rohrer, R. A.

    1983-04-01

    Consideration is given to the development status of the use of computers in automated integrated circuit design methods, which promise the minimization of both design time and design error incidence. Integrated circuit design encompasses two major tasks: error specification, in which the goal is a logic diagram that accurately represents the desired electronic function, and physical specification, in which the goal is an exact description of the physical locations of all circuit elements and their interconnections on the chip. Design automation not only saves money by reducing design and fabrication time, but also helps the community of systems and logic designers to work more innovatively. Attention is given to established design automation methodologies, programmable logic arrays, and design shortcuts.

  18. Embedded systems circuits and programming

    CERN Document Server

    Sanchez, Julio

    2012-01-01

    During the development of an engineered product, developers often need to create an embedded system--a prototype--that demonstrates the operation/function of the device and proves its viability. Offering practical tools for the development and prototyping phases, Embedded Systems Circuits and Programming provides a tutorial on microcontroller programming and the basics of embedded design. The book focuses on several development tools and resources: Standard and off-the-shelf components, such as input/output devices, integrated circuits, motors, and programmable microcontrollers The implementat

  19. Circuit modeling for electromagnetic compatibility

    CERN Document Server

    Darney, Ian B

    2013-01-01

    Very simply, electromagnetic interference (EMI) costs money, reduces profits, and generally wreaks havoc for circuit designers in all industries. This book shows how the analytic tools of circuit theory can be used to simulate the coupling of interference into, and out of, any signal link in the system being reviewed. The technique is simple, systematic and accurate. It enables the design of any equipment to be tailored to meet EMC requirements. Every electronic system consists of a number of functional modules interconnected by signal links and power supply lines. Electromagnetic interference

  20. Simplified design of filter circuits

    CERN Document Server

    Lenk, John

    1999-01-01

    Simplified Design of Filter Circuits, the eighth book in this popular series, is a step-by-step guide to designing filters using off-the-shelf ICs. The book starts with the basic operating principles of filters and common applications, then moves on to describe how to design circuits by using and modifying chips available on the market today. Lenk's emphasis is on practical, simplified approaches to solving design problems.Contains practical designs using off-the-shelf ICsStraightforward, no-nonsense approachHighly illustrated with manufacturer's data sheets

  1. Fermionic models with superconducting circuits

    Energy Technology Data Exchange (ETDEWEB)

    Las Heras, Urtzi; Garcia-Alvarez, Laura; Mezzacapo, Antonio; Lamata, Lucas [University of the Basque Country UPV/EHU, Department of Physical Chemistry, Bilbao (Spain); Solano, Enrique [University of the Basque Country UPV/EHU, Department of Physical Chemistry, Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, Bilbao (Spain)

    2015-12-01

    We propose a method for the efficient quantum simulation of fermionic systems with superconducting circuits. It consists in the suitable use of Jordan-Wigner mapping, Trotter decomposition, and multiqubit gates, be with the use of a quantum bus or direct capacitive couplings. We apply our method to the paradigmatic cases of 1D and 2D Fermi-Hubbard models, involving couplings with nearest and next-nearest neighbours. Furthermore, we propose an optimal architecture for this model and discuss the benchmarking of the simulations in realistic circuit quantum electrodynamics setups. (orig.)

  2. Short-circuit impedance measurement

    DEFF Research Database (Denmark)

    Pedersen, Knud Ole Helgesen; Nielsen, Arne Hejde; Poulsen, Niels Kjølstad

    2003-01-01

    Methods for estimating the short-circuit impedance in the power grid are investigated for various voltage levels and situations. The short-circuit impedance is measured, preferably from naturally occurring load changes in the grid, and it is shown that such a measurement system faces different...... kinds of problems at different locations in the grid. This means that the best measurement methodology changes depending on the location in the grid. Three typical examples with different measurement problems at 400 kV, 132 kV and 400 V voltage level are discussed....

  3. Circuit, Thermal and Cost Characteristics of Impulse Magnetizing Circuits

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper describes the development of circuit, thermal and cost model for a capacitor discharge impulse megnetizer and compares simulations to measurements from an actual system. We used a cost structure consisting of five major subsystems for cost modeling. Especially, we estimated the potential for cost reductions impulse magnetizer as a function of time using the learning curve.

  4. Relaxation Based Electrical Simulation for VLSI Circuits

    Directory of Open Access Journals (Sweden)

    S. Rajkumar

    2012-06-01

    Full Text Available Electrical circuit simulation was one of the first CAD tools developed for IC design. The conventional circuit simulators like SPICE and ASTAP were designed initially for the cost effective analysis of circuits containing a few hundred transistors or less. A number of approaches have been used to improve the performances of congenital circuit simulators for the analysis of large circuits. Thereafter relaxation methods was proposed to provide more accurate waveforms than standard circuit simulators with up to two orders of magnitude speed improvement for large circuits. In this paper we have tried to highlights recently used waveform and point relaxation techniques for simulation of VLSI circuits. We also propose a simple parallelization technique and experimentally demonstrate that we can solve digital circuits with tens of million transistors in a few hours.

  5. An Approach to Simplify Reversible Logic Circuits

    Directory of Open Access Journals (Sweden)

    Pabitra Roy

    2012-09-01

    Full Text Available Energy loss is one of the major problems in traditional irreversible circuits. For every bit of information loss kTln2 joules of heat is lost. In order to reduce the energy loss the concept of reversible logic circuits are introduced. Here we have described an algorithm for simplifying the reversible logic circuit and hence reduction of circuit cost and energy. The algorithm considers sub_circuit with respect to their number of lines and contiguous gates. The resulting sub_circuits are re-synthesized with smaller equivalent implementation. The process continues until circuit cost reaches good enough for Application or until a given computation budget has been exhausted. The circuit is constructed by NOT, CNOT and Toffoli gates only. By applying the algorithm and using the equivalent implementation we will get significant reduction of circuit cost and hence energy.

  6. Clocking Scheme for Switched-Capacitor Circuits

    DEFF Research Database (Denmark)

    Steensgaard-Madsen, Jesper

    1998-01-01

    A novel clocking scheme for switched-capacitor (SC) circuits is presented. It can enhance the understanding of SC circuits and the errors caused by MOSFET (MOS) switches. Charge errors, and techniques to make SC circuits less sensitive to them are discussed.......A novel clocking scheme for switched-capacitor (SC) circuits is presented. It can enhance the understanding of SC circuits and the errors caused by MOSFET (MOS) switches. Charge errors, and techniques to make SC circuits less sensitive to them are discussed....

  7. Digital circuit boards mach 1 GHz

    CERN Document Server

    Morrison, Ralph

    2012-01-01

    A unique, practical approach to the design of high-speed digital circuit boards The demand for ever-faster digital circuit designs is beginning to render the circuit theory used by engineers ineffective. Digital Circuit Boards presents an alternative to the circuit theory approach, emphasizing energy flow rather than just signal interconnection to explain logic circuit behavior. The book shows how treating design in terms of transmission lines will ensure that the logic will function, addressing both storage and movement of electrical energy on these lines. It cove

  8. Separating OR, SUM, and XOR Circuits

    OpenAIRE

    Find, Magnus; Göös, Mika; Järvisalo, Matti; Kaski, Petteri; Koivisto, Mikko; Korhonen, Janne H.

    2013-01-01

    Given a boolean n by n matrix A we consider arithmetic circuits for computing the transformation x->Ax over different semirings. Namely, we study three circuit models: monotone OR-circuits, monotone SUM-circuits (addition of non-negative integers), and non-monotone XOR-circuits (addition modulo 2). Our focus is on \\emph{separating} these models in terms of their circuit complexities. We give three results towards this goal: (1) We prove a direct sum type theorem on the monotone complexity of ...

  9. Advanced circuit simulation using Multisim workbench

    CERN Document Server

    Báez-López, David; Cervantes-Villagómez, Ofelia Delfina

    2012-01-01

    Multisim is now the de facto standard for circuit simulation. It is a SPICE-based circuit simulator which combines analog, discrete-time, and mixed-mode circuits. In addition, it is the only simulator which incorporates microcontroller simulation in the same environment. It also includes a tool for printed circuit board design.Advanced Circuit Simulation Using Multisim Workbench is a companion book to Circuit Analysis Using Multisim, published by Morgan & Claypool in 2011. This new book covers advanced analyses and the creation of models and subcircuits. It also includes coverage of transmissi

  10. A circuit mechanism for neurodegeneration.

    Science.gov (United States)

    Roselli, Francesco; Caroni, Pico

    2012-10-12

    How deficiency in SMN1 selectively affects motoneurons in spinal muscular atrophy is poorly understood. Here, Imlach et al. and Lotti et al. show that aberrant splicing of Stasimon in cholinergic sensory neurons and interneurons leads to motoneuron degeneration, suggesting that altered circuit function may underlie the disorder.

  11. Circuit design for RF transceivers

    CERN Document Server

    Leenaerts, Domine; Vaucher, Cicero S

    2007-01-01

    Second edition of this successful 2001 RF Circuit Design book, has been updated, latest technology reviews have been added as well as several actual case studies. Due to the authors being active in industry as well as academia, this should prove to be an essential guide on RF Transceiver Design for students and engineers.

  12. Integrated Circuit Stellar Magnitude Simulator

    Science.gov (United States)

    Blackburn, James A.

    1978-01-01

    Describes an electronic circuit which can be used to demonstrate the stellar magnitude scale. Six rectangular light-emitting diodes with independently adjustable duty cycles represent stars of magnitudes 1 through 6. Experimentally verifies the logarithmic response of the eye. (Author/GA)

  13. Unbalanced Neuronal Circuits in Addiction

    OpenAIRE

    Volkow, Nora D; Wang, Gen-Jack; Tomasi, Dardo; Baler, Ruben D.

    2013-01-01

    Through sequential waves of drug-induced neurochemical stimulation, addiction co-opts the brain's neuronal circuits that mediate reward, motivation, , to behavioral inflexibility and a severe disruption of self-control and compulsive drug intake. Brain imaging technologies have allowed neuroscientists to map out the neural landscape of addiction in the human brain and to understand how drugs modify it.

  14. 77 FR 50166 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Science.gov (United States)

    2012-08-20

    ... contactor in series with the circuit breaker in lieu of circuit breakers alone. The petitioner states that the circuit breaker would provide short circuit protection and the contactor would be equipped to... contactor will be rated for the maximum voltage of the circuit being protected and the continuous full...

  15. The voltage-current relationship and equivalent circuit implementation of parallel flux-controlled memristive circuits

    Institute of Scientific and Technical Information of China (English)

    Bao Bo-Cheng; Feng Fei; Dong Wei; Pan Sai-Hu

    2013-01-01

    A flux-controlled memristor characterized by smooth cubic nonlinearity is taken as an example,upon which the voltage-current relationships (VCRs) between two parallel memristive circuits-a parallel memristor and capacitor circuit (the parallel MC circuit),and a parallel memristor and inductor circuit (the parallel ML circuit)-are investigated.The results indicate that the VCR between these two parallel memristive circuits is closely related to the circuit parameters,and the frequency and amplitude of the sinusoidal voltage stimulus.An equivalent circuit model of the memristor is built,upon which the circuit simulations and experimental measurements of both the parallel MC circuit and the parallel ML circuit are performed,and the results verify the theoretical analysis results.

  16. Filter cake breaker systems

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Marcelo H.F. [Poland Quimica Ltda., Duque de Caxias, RJ (Brazil)

    2004-07-01

    Drilling fluids filter cakes are based on a combination of properly graded dispersed particles and polysaccharide polymers. High efficiency filter cakes are formed by these combination , and their formation on wellbore walls during the drilling process has, among other roles, the task of protecting the formation from instantaneous or accumulative invasion of drilling fluid filtrate, granting stability to well and production zones. Filter cake minimizes contact between drilling fluid filtrate and water, hydrocarbons and clay existent in formations. The uniform removal of the filter cake from the entire interval is a critical factor of the completion process. The main methods used to breaking filter cake are classified into two groups, external or internal, according to their removal mechanism. The aim of this work is the presentation of these mechanisms as well their efficiency. (author)

  17. Bayes Ice-Breaker

    Science.gov (United States)

    Jessop, Alan

    2010-01-01

    Showing simply how statistical thinking can help in weighing evidence and reaching decisions can be useful both as an introduction to an extended presentation of statistical theory and as an introduction to a looser discussion of the nature and value of data.

  18. Beijing Back Breakers

    Institute of Scientific and Technical Information of China (English)

    MICHAEL; L.; O’NEAL

    2010-01-01

    When I first arrived here a few months ago, I couldn’t help but notice several work projects going on all around me. A new dorm was being built on campus where I would be teaching, as well as a courtyard being repaved and bricked in front of the female students’ dormitory, and a building next to my gym was being renovated.

  19. Beijing Back Breakers

    Institute of Scientific and Technical Information of China (English)

    MICHAEL L. O'NEAL

    2010-01-01

    @@ When I first arrived here a few months ago, I couldn't help but notice several work projects going on all around me. A new dorm was being built on campus where I would be teach-ing, as well as a courtyard being repaved and bricked in front of the female students' dormitory, and a building next to my gym was being renovated. I wondered how long it would take to finish these large tasks, espe-cially the courtyard, as school would begin in about a week, and it would be a mess for students to have to walk through mud, over piles of sand, and around stacks of bricks to get where they wanted to go.

  20. Analog Nonvolatile Computer Memory Circuits

    Science.gov (United States)

    MacLeod, Todd

    2007-01-01

    In nonvolatile random-access memory (RAM) circuits of a proposed type, digital data would be stored in analog form in ferroelectric field-effect transistors (FFETs). This type of memory circuit would offer advantages over prior volatile and nonvolatile types: In a conventional complementary metal oxide/semiconductor static RAM, six transistors must be used to store one bit, and storage is volatile in that data are lost when power is turned off. In a conventional dynamic RAM, three transistors must be used to store one bit, and the stored bit must be refreshed every few milliseconds. In contrast, in a RAM according to the proposal, data would be retained when power was turned off, each memory cell would contain only two FFETs, and the cell could store multiple bits (the exact number of bits depending on the specific design). Conventional flash memory circuits afford nonvolatile storage, but they operate at reading and writing times of the order of thousands of conventional computer memory reading and writing times and, hence, are suitable for use only as off-line storage devices. In addition, flash memories cease to function after limited numbers of writing cycles. The proposed memory circuits would not be subject to either of these limitations. Prior developmental nonvolatile ferroelectric memories are limited to one bit per cell, whereas, as stated above, the proposed memories would not be so limited. The design of a memory circuit according to the proposal must reflect the fact that FFET storage is only partly nonvolatile, in that the signal stored in an FFET decays gradually over time. (Retention times of some advanced FFETs exceed ten years.) Instead of storing a single bit of data as either a positively or negatively saturated state in a ferroelectric device, each memory cell according to the proposal would store two values. The two FFETs in each cell would be denoted the storage FFET and the control FFET. The storage FFET would store an analog signal value

  1. Driver circuit for solid state light sources

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, Fred; Denvir, Kerry; Allen, Steven

    2016-02-16

    A driver circuit for a light source including one or more solid state light sources, a luminaire including the same, and a method of so driving the solid state light sources are provided. The driver circuit includes a rectifier circuit that receives an alternating current (AC) input voltage and provides a rectified AC voltage. The driver circuit also includes a switching converter circuit coupled to the light source. The switching converter circuit provides a direct current (DC) output to the light source in response to the rectified AC voltage. The driver circuit also includes a mixing circuit, coupled to the light source, to switch current through at least one solid state light source of the light source in response to each of a plurality of consecutive half-waves of the rectified AC voltage.

  2. Plug-in integrated/hybrid circuit

    Science.gov (United States)

    Stringer, E. J.

    1974-01-01

    Hybrid circuitry can be installed into standard round bayonet connectors, to eliminate wiring from connector to circuit. Circuits can be connected directly into either section of connector pair, eliminating need for hard wiring to that section.

  3. Brain-machine interface circuits and systems

    CERN Document Server

    Zjajo, Amir

    2016-01-01

    This book provides a complete overview of significant design challenges in respect to circuit miniaturization and power reduction of the neural recording system, along with circuit topologies, architecture trends, and (post-silicon) circuit optimization algorithms. The introduced novel circuits for signal conditioning, quantization, and classification, as well as system configurations focus on optimized power-per-area performance, from the spatial resolution (i.e. number of channels), feasible wireless data bandwidth and information quality to the delivered power of implantable system.

  4. Black hole qubit correspondence from quantum circuits

    CERN Document Server

    Prudencio, Thiago; Silva, Edilberto O; Belich, Humberto

    2014-01-01

    We propose a black hole qubit correspondence (BHQC) from quantum circuits, taking into account the BHQC formulations of wrapped brane qubits. With base on BHQC, we implement the corresponding gate operations to realize any given quantum circuit. In particular, we implement cases of the generation of Bell states, quantum teleportation and GHZ states circuits. Finally, we give an interpretation of the BHQC from quantum circuits with base on the BHQC classification of entanglement classes.

  5. 49 CFR 236.721 - Circuit, control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, control. 236.721 Section 236.721..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.721 Circuit, control. An electrical circuit between a source of electric energy and a device which it operates....

  6. Equivalence Checking of Hierarchical Combinational Circuits

    DEFF Research Database (Denmark)

    Williams, Poul Frederick; Hulgaard, Henrik; Andersen, Henrik Reif

    1999-01-01

    This paper presents a method for verifying that two hierarchical combinational circuits implement the same Boolean functions. The key new feature of the method is its ability to exploit the modularity of circuits to reuse results obtained from one part of the circuits in other parts. We demonstrate...

  7. An eigenvalue study of the MLC circuit

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.

    1998-01-01

    The MLC (Murali-Lakshmanan-Chua) circuit is the simplest non-autonomous chaotic circuit. Insight in the behaviour of the circuit is obtained by means of a study of the eigenvalues of the linearized Jacobian of the nonlinear differential equations. The trajectories of the eigenvalues as functions...

  8. An Equivalent Circuit for Landau Damping

    DEFF Research Database (Denmark)

    Pécseli, Hans

    1976-01-01

    An equivalent circuit simulating the effect of Landau damping in a stable plasma‐loaded parallel‐plate capacitor is presented. The circuit contains a double infinity of LC components. The transition from stable to unstable plasmas is simulated by the introduction of active elements into the circuit....

  9. 49 CFR 236.731 - Controller, circuit.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Controller, circuit. 236.731 Section 236.731 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Controller, circuit. A device for opening and closing electric circuits....

  10. A Current-mode Logarithmic Function Circuit

    OpenAIRE

    Osama Oglah Faris; Muhammad Taher Abuelma'atti

    2004-01-01

    A new current-mode analog circuit configuration that implements the function ln (x/y) is proposed. The circuit uses bipolar transistors and resistors and is suitable for integration. In the proposed circuit the ratio (x/y) can be larger or smaller than unity. Simulation results are included.

  11. 47 CFR 32.2232 - Circuit equipment.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Circuit equipment. 32.2232 Section 32.2232... FOR TELECOMMUNICATIONS COMPANIES Instructions for Balance Sheet Accounts § 32.2232 Circuit equipment... which is used for the amplification, modulation, regeneration, circuit patching, balancing or control...

  12. 49 CFR 236.726 - Circuit, track.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, track. 236.726 Section 236.726 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Circuit, track. An electrical circuit of which the rails of the track form a part....

  13. 30 CFR 56.6407 - Circuit testing.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit testing. 56.6407 Section 56.6407... Blasting § 56.6407 Circuit testing. A blasting galvanometer or other instrument designed for testing blasting circuits shall be used to test each of the following: (a) Continuity of each electric detonator...

  14. 30 CFR 57.6407 - Circuit testing.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit testing. 57.6407 Section 57.6407... Blasting-Surface and Underground § 57.6407 Circuit testing. A blasting galvanometer or other instrument designed for testing blasting circuits shall be used to test the following: (a) In surface operations—...

  15. 30 CFR 75.1323 - Blasting circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Blasting circuits. 75.1323 Section 75.1323... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1323 Blasting circuits. (a) Blasting circuits shall be protected from sources of stray electric current. (b) Detonators made...

  16. New Logic Circuit with DC Parametric Excitation

    Science.gov (United States)

    Sugahara, Masanori; Kaneda, Hisayoshi

    1982-12-01

    It is shown that dc parametric excitation is possible in a circuit named JUDO, which is composed of two resistively-connected Josephson junctions. Simulation study proves that the circuit has large gain and properties suitable for the construction of small, high-speed logic circuits.

  17. PRINCIPLES OF IMPLEMENTATION OF CURRENT PROTECTION FROM INTERPHASE SHORT-CIRCUITS ON THE POWER LINES WITH UNILATERAL FEED

    Directory of Open Access Journals (Sweden)

    F. A. Romaniuk

    2015-01-01

    Full Text Available The article describes the implementation of the principle of overcurrent protection from interphase  short-circuits  on  the  power  lines  with  unilateral  feed.  The  expression  of  the detection of the fault location by the relative value of the distance from the installation of pro- tection to the point of damage with the help of the results of operational control of the short- circuit current damaged phases has been suggested in the article. Also the expression for determining  the  time  delay response  for  such  protection  has been  presented,  taking  into account fault location that had been detected.The paper proposes and describes the functional diagram of the overcurrent protection in detail, provides realization of the implementation of the principles set out in the article. Paper content includes the description of the elements of the considered overcurrent protection, such as input current transducers connected to the measuring current transformers of the protected line, maxiselector, miniselector, block of the determination of the mode type, the measuring unit with the setting unit, detecting fault location unit with the setting unit, calculation unit and control unit with time delay parameter setting, an OR gate, the actuating element, that opens circuit breaker of the protected line. The operation of the proposed scheme is reviewed in  the  article.  All  units  and  elements  of functional  circuit overcurrent protection  can  be implemented with the help of analog and digital technology. Modern microprocessors can be used for these purposes.The efficiency of provided implementation of the principles of overcurrent protection from phase-to-phase short circuits on the power lines with unilateral feed was studied by computational experiments. These results confirm the effectiveness of the proposed solutions and also trip of short-circuit within the main zone line protection is provided without

  18. Calculation and Protection Selection of Single-phase Short-circuit Current for the City Road Lighting%城市道路照明单相短路电流的计算和保护选择

    Institute of Scientific and Technical Information of China (English)

    杨喜云

    2015-01-01

    This paper expounds the importance of the single-phase ( grounding) short-circuit current calculation and protection selection for the road lighting.And through the instance of the single-phase (grounding) short-circuit current calculation and the instance of choosing low-voltage circuit-breakers, this paper introduces the effective protective measures towards the problem of the low-voltage circuit-breaker’s lack of action sensitivity in practical use.%阐述了道路照明单相(接地)短路故障电流计算和保护选择的重要性,并通过单相(接地)短路故障电流计算和低压断路器的选择实例,简单介绍了在实际运用中,针对低压断路器动作灵敏性不足的问题采取的比较有效的保护措施。

  19. Integrated circuits for multimedia applications

    DEFF Research Database (Denmark)

    Vandi, Luca

    2007-01-01

    , and it is applied to a broad-band dual-loop receiver architecture in order to boost the linearity performances of the stage. A simplified noise- and linearity analysis of the circuit is derived, and a comparison is provided with a more traditional dual-loop topology (a broad-band stage based on shunt......This work presents several key aspects in the design of RF integrated circuits for portable multimedia devices. One chapter is dedicated to the application of negative-feedback topologies to receiver frontends. A novel feedback technique suitable for common multiplier-based mixers is described......-series feedback), showing a difference in compression point in the order of 10dBm for the same power consumption. The same principle is also applied to a more conventional narrow-band stage in which a single loop is employed in order to enhance noise performances. Noise analysis shows sensible improvements...

  20. Handbook of microwave integrated circuits

    Science.gov (United States)

    Hoffmann, Reinmut K.

    The design and operation of ICs for use in the 0.5-20-GHz range are described in an introductory and reference work for industrial engineers. Chapters are devoted to an overview of microwave IC (MIC) technology, general stripline characteristics, microwave transmission line (MTL) parameters for microstrips with isotropic dielectric substrates, higher-order modes on a microstrip, the effects of metallic enclosure on MTL transmission parameters, losses in microstrips, the measurement of MTL parameters, and MTLs on anisotropic dielectric substrates. Consideration is given to coupled microstrips on dielectric substrates, microstrip discontinuities, radiation from microstrip circuits, MTL variations, coplanar MTLs, slotlines, and spurious modes in MTL circuits. Diagrams, drawings, graphs, and a glossary of symbols are provided.

  1. Ionization tube simmer current circuit

    Science.gov (United States)

    Steinkraus, Jr., Robert F.

    1994-01-01

    A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

  2. Delay locked loop integrated circuit.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2007-10-01

    This report gives a description of the development of a Delay Locked Loop (DLL) integrated circuit (IC). The DLL was developed and tested as a stand-alone IC test chip to be integrated into a larger application specific integrated circuit (ASIC), the Quadrature Digital Waveform Synthesizer (QDWS). The purpose of the DLL is to provide a digitally programmable delay to enable synchronization between an internal system clock and external peripherals with unknown clock skew. The DLL was designed and fabricated in the IBM 8RF process, a 0.13 {micro}m CMOS process. It was designed to operate with a 300MHz clock and has been tested up to 500MHz.

  3. A Synchronization Method of Breaker Manual Closing for Smart Substations%一种智能变电站手合检同期的方法

    Institute of Scientific and Technical Information of China (English)

    张敏; 刘湘琼; 范培培; 沈健

    2012-01-01

    A synchronization method of breaker manual closing,which is suitable to smart substation characteristics is presented.The synchronization sampling signal is based on IEC 61850-9-2 acquired value transfer standard which adequately considers the abnormal situations such as losing sample value points and sample value sequence asynchronous between channels,etc.The sample value is re-sampled and re-sampling frequency is tracking with real signal so that ensures the accuracy of synchronization measurement.The results of synchronization judgment creates communication model and through general object-oriented substation event(GOOSE) output control smart execution terminal provides lock for breaker manual closing.The proposed method is realized in measuring and control device of smart substation and applied in engineering projects.%提出了一种适合智能变电站特点的手合检同期方法。同期采样基于IEC 61850-9-2采样值传输标准,充分考虑采样过程的丢点、不同步等异常处理。进行频率跟踪重采样,保证同期量测精度。按检同期结果建立通信模型,通过通用面向对象的变电站事件(GOOSE)输出控制智能终端,为手合操作提供闭锁。所提出方法已在智能变电站测控装置中实现并在工程中得到应用。

  4. Synthetic circuits, devices and modules

    OpenAIRE

    Zhang, Hong; Jiang, Taijiao

    2010-01-01

    The aim of synthetic biology is to design artificial biological systems for novel applications. From an engineering perspective, construction of biological systems of defined functionality in a hierarchical way is fundamental to this emerging field. Here, we highlight some current advances on design of several basic building blocks in synthetic biology including the artificial gene control elements, synthetic circuits and their assemblies into devices and modules. Such engineered basic buildi...

  5. ?Immunetworks?, intersecting circuits and dynamics

    OpenAIRE

    Demongeot, Jacques; Elena, Adrien; Noual, Mathilde; Sené, Sylvain; Thuderoz, Florence

    2011-01-01

    Abstract This paper proposes a study of biological regulatory networks based on a multi-level strategy. Given a network, the first structural level of this strategy consists in analysing the architecture of the network interactions in order to describe it. The second dynamical level consists in relating the patterns found in the architecture to the possible dynamical behaviours of the network. It is known that circuits are the patterns that play the most important part in the dynam...

  6. Microcontroller based Integrated Circuit Tester

    OpenAIRE

    Yousif Taha Yousif Elamin; Abdelrasoul Jabar Alzubaidi

    2015-01-01

    The digital integrated circuit (IC) tester is implemented by using the ATmega32 microcontroller . The microcontroller processes the inputs and outputs and displays the results on a Liquid Crystal Display (LCD). The basic function of the digital IC tester is to test a digital IC for correct logical functioning as described in the truth table and/or function table. The designed model can test digital ICs having 14 pins. Since it is programmable, any number of ICs can be tested . Thi...

  7. Monolithic readout circuits for RHIC

    Energy Technology Data Exchange (ETDEWEB)

    O`Connor, P.; Harder, J. [Brookhaven National Laboratory, Upton, NY (United States)

    1991-12-31

    Several CMOS ASICs have been developed for a proposed RHIC experiment. This paper discusses why ASIC implementation was chosen for certain functions, circuit specifications and the design techniques used to meet them, and results of simulations and early prototypes. By working closely together from an early stage in the planning process, in-house ASIC designers and detector and data acquisition experimenters can achieve optimal use of this important technology.

  8. CIRCUIT SWITCHING VERSUS PACKET SWITCHING

    OpenAIRE

    Sneps-Sneppe, Manfred

    2015-01-01

    Communication specialists around the world are facing the same problem: shifting from circuit switching (CS) to packet switching (CS). Communication service providers are favoring “All-over-IP” technologies hoping to boost their profits by providing multimedia services. The main stakeholder in this field of the paradigm shift is the industry itself: packet switching hardware manufacturers are going to earn billions of dollars and thus pay engineers and journalists many millions for the promot...

  9. An Interpreter for Quantum Circuits

    OpenAIRE

    Lucas Helms; Ruben Gamboa

    2013-01-01

    This paper describes an ACL2 interpreter for "netlists" describing quantum circuits. Several quantum gates are implemented, including the Hadamard gate H, which rotates vectors by 45 degrees, necessitating the use of irrational numbers, at least at the logical level. Quantum measurement presents an especially difficult challenge, because it requires precise comparisons of irrational numbers and the use of random numbers. This paper does not address computation with irrational numbers or the g...

  10. Circuit analysis of quantum measurement

    OpenAIRE

    Kurotani, Yuji; Ueda, Masahito

    2006-01-01

    We develop a circuit theory that enables us to analyze quantum measurements on a two-level system and on a continuous-variable system on an equal footing. As a measurement scheme applicable to both systems, we discuss a swapping state measurement which exchanges quantum states between the system and the measuring apparatus before the apparatus meter is read out. This swapping state measurement has an advantage in gravitational-wave detection over contractive state measurement in that the post...

  11. Quantum Circuits with Mixed States

    CERN Document Server

    Aharonov, D; Nisan, N; Aharonov, Dorit; Kitaev, Alexei; Nisan, Noam

    1998-01-01

    We define the model of quantum circuits with density matrices, where non-unitary gates are allowed. Measurements in the middle of the computation, noise and decoherence are implemented in a natural way in this model, which is shown to be equivalent in computational power to standard quantum circuits. The main result in this paper is a solution for the subroutine problem: The general function that a quantum circuit outputs is a probabilistic function, but using pure state language, such a function can not be used as a black box in other computations. We give a natural definition of using general subroutines, and analyze their computational power. We suggest convenient metrics for quantum computing with mixed states. For density matrices we analyze the so called ``trace metric'', and using this metric, we define and discuss the ``diamond metric'' on superoperators. These metrics enable a formal discussion of errors in the computation. Using a ``causality'' lemma for density matrices, we also prove a simple lowe...

  12. Ultra-low power integrated circuit design circuits, systems, and applications

    CERN Document Server

    Li, Dongmei; Wang, Zhihua

    2014-01-01

    This book describes the design of CMOS circuits for ultra-low power consumption including analog, radio frequency (RF), and digital signal processing circuits (DSP). The book addresses issues from circuit and system design to production design, and applies the ultra-low power circuits described to systems for digital hearing aids and capsule endoscope devices. Provides a valuable introduction to ultra-low power circuit design, aimed at practicing design engineers; Describes all key building blocks of ultra-low power circuits, from a systems perspective; Applies circuits and systems described to real product examples such as hearing aids and capsule endoscopes.

  13. CMOS circuit design, layout and simulation

    CERN Document Server

    Baker, R Jacob

    2010-01-01

    The Third Edition of CMOS Circuit Design, Layout, and Simulation continues to cover the practical design of both analog and digital integrated circuits, offering a vital, contemporary view of a wide range of analog/digital circuit blocks including: phase-locked-loops, delta-sigma sensing circuits, voltage/current references, op-amps, the design of data converters, and much more. Regardless of one's integrated circuit (IC) design skill level, this book allows readers to experience both the theory behind, and the hands-on implementation of, complementary metal oxide semiconductor (CMOS) IC design via detailed derivations, discussions, and hundreds of design, layout, and simulation examples.

  14. Design of analog circuits through symbolic analysis

    CERN Document Server

    Fakhfakh, Mourad; V Fernández, Francisco

    2012-01-01

    Symbolic analyzers have the potential to offer knowledge to sophomores as well as practitioners of analog circuit design. Actually, they are an essential complement to numerical simulators, since they provide insight into circuit behavior which numerical analyzers do not provide. Symbolic analysis of electronic circuits addresses the generation of symbolic expressions for the parameters that describe the performance of linear and nonlinear circuits in three domains: DC, AC and time; some or all the circuit parameters can be kept as symbols. Due to the fact that these expressions remain va

  15. Method and Circuit for Injecting a Precise Amount of Charge onto a Circuit Node

    Science.gov (United States)

    Hancock, Bruce R. (Inventor)

    2016-01-01

    A method and circuit for injecting charge into a circuit node, comprising (a) resetting a capacitor's voltage through a first transistor; (b) after the resetting, pre-charging the capacitor through the first transistor; and (c) after the pre-charging, further charging the capacitor through a second transistor, wherein the second transistor is connected between the capacitor and a circuit node, and the further charging draws charge through the second transistor from the circuit node, thereby injecting charge into the circuit node.

  16. Design of superconductor frame compression circuits

    Science.gov (United States)

    Sakurai, T.; Miyaho, N.; Miyahara, K.

    2007-10-01

    We proposed previously a novel interface circuit which was used between semiconductor data-input circuits and superconductor high-speed routers. The frame length of data packets is compressed in the interface circuit. Our proposed interface circuit has rather narrow timing margin. The problem was that our control circuit of the interface circuit could allow only very small timing delay. In this paper we propose a modified control circuit. We have improved the timing margin of the control circuit using RS-flip flop (RS-FF), where two shift registers and one control circuit are driven by clock pulses provided from a master clock-pulse generator. In this circuit, we have assumed fixed frame length packets. Our final target of master clock frequency is 100 GHz which will be realized with the device-parameter set of future advanced process. As the first step of realizing this target value, we aimed at 40 GHz clock operation with the conventional device-parameter set of NECs standard I process. The behavior of the whole frame compression circuit was simulated by a computer, and it was confirmed that it operated properly up to the master clock frequency of 23 GHz.

  17. Optimal Design of Control Loop of Special Breaker of 10 kV Capacitor Bank%10 kV电容器组专用断路器控制回路优化设计

    Institute of Scientific and Technical Information of China (English)

    崔勇; 王川; 牛满萍; 代鑫波

    2012-01-01

    In view of problem that closing coil in control loop of breaker often happens burnout when breaker of 10 kV capacitor bank makes breaking-closing control operation, the paper proposed an optimal design scheme of double control loops of closing coil of breaker. The scheme adds standby closing control loop in original closing control loop of breaker. When main closing coil is burnout, standby closing coil is charged to close breaker. The standby closing control loop series signal relay which can send out fault signal after main closing coil is burnout and can ensure terminal voltage of standby closing coil is uniform with one of main closing coil. The actual application shows that the optimal design scheme solves problem that closing coil of breaker cannot close timely after it is burnout and ensures normal on/off of capacitor bank.%针对10 kV电容器组断路器进行分合闸控制操作时经常发生断路器控制回路合闸线圈烧毁的问题,提出了一种断路器双合闸线圈控制回路的优化设计方案.该方案在原有的断路器合闸控制回路中增加了备用合闸控制回路,当主合闸线圈烧毁时,备用合闸线圈充电,合上断路器;备用合闸控制回路中串联了信号继电器,当主合闸线圈烧毁后信号继电器可发出故障信号,同时可保证备用合闸线圈端电压与主合闸线圈端电压保持一致.实际应用表明,该优化设计方案从根本上解决了断路器合闸线圈烧毁后不能及时合闸的问题,保证了电容器组的正常投退.

  18. Fractional linear systems and electrical circuits

    CERN Document Server

    Kaczorek, Tadeusz

    2015-01-01

    This monograph covers some selected problems of positive and fractional electrical circuits composed of resistors, coils, capacitors and voltage (current) sources. The book consists of 8 chapters, 4 appendices and a list of references. Chapter 1 is devoted to fractional standard and positive continuous-time and discrete-time linear systems without and with delays. In chapter 2 the standard and positive fractional electrical circuits are considered and the fractional electrical circuits in transient states are analyzed.  Descriptor linear electrical circuits and their properties are investigated in chapter 3,  while chapter 4 is devoted to the stability of fractional standard and positive linear electrical circuits. The reachability, observability and reconstructability of fractional positive electrical circuits and their decoupling zeros are analyzed in chapter 5. The fractional linear electrical circuits with feedbacks are considered in chapter 6. In chapter 7 solutions of minimum energy control for standa...

  19. Model Order Reduction for Electronic Circuits:

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Shontz, Suzanne

    Electronic circuits are ubiquitous; they are used in numerous industries including: the semiconductor, communication, robotics, auto, and music industries (among many others). As products become more and more complicated, their electronic circuits also grow in size and complexity. This increased...... the need for circuit simulators to evaluate potential designs before fabrication, as integrated circuit prototypes are expensive to build, and troubleshooting is difficult. In this report, we focus on the simulation of printed circuit boards (PCB’s) and interconnects both of which are of great importance...... in the semiconductor industry. Circuit simulation proceeds by using Maxwell’s equations to create a mathematical model of the circuit. The boundary element method is then used to discretize the equations, and the variational form of the equations are then solved on the graph network....

  20. Auto-programmable impulse neural circuits

    Science.gov (United States)

    Watula, D.; Meador, J.

    1990-01-01

    Impulse neural networks use pulse trains to communicate neuron activation levels. Impulse neural circuits emulate natural neurons at a more detailed level than that typically employed by contemporary neural network implementation methods. An impulse neural circuit which realizes short term memory dynamics is presented. The operation of that circuit is then characterized in terms of pulse frequency modulated signals. Both fixed and programmable synapse circuits for realizing long term memory are also described. The implementation of a simple and useful unsupervised learning law is then presented. The implementation of a differential Hebbian learning rule for a specific mean-frequency signal interpretation is shown to have a straightforward implementation using digital combinational logic with a variation of a previously developed programmable synapse circuit. This circuit is expected to be exploited for simple and straightforward implementation of future auto-adaptive neural circuits.

  1. Graphene radio frequency receiver integrated circuit.

    Science.gov (United States)

    Han, Shu-Jen; Garcia, Alberto Valdes; Oida, Satoshi; Jenkins, Keith A; Haensch, Wilfried

    2014-01-01

    Graphene has attracted much interest as a future channel material in radio frequency electronics because of its superior electrical properties. Fabrication of a graphene integrated circuit without significantly degrading transistor performance has proven to be challenging, posing one of the major bottlenecks to compete with existing technologies. Here we present a fabrication method fully preserving graphene transistor quality, demonstrated with the implementation of a high-performance three-stage graphene integrated circuit. The circuit operates as a radio frequency receiver performing signal amplification, filtering and downconversion mixing. All circuit components are integrated into 0.6 mm(2) area and fabricated on 200 mm silicon wafers, showing the unprecedented graphene circuit complexity and silicon complementary metal-oxide-semiconductor process compatibility. The demonstrated circuit performance allow us to use graphene integrated circuit to perform practical wireless communication functions, receiving and restoring digital text transmitted on a 4.3-GHz carrier signal.

  2. Pragmatic circuits signals and filters

    CERN Document Server

    Eccles, William

    2006-01-01

    Pragmatic Circuits: Signals and Filters is built around the processing of signals. Topics include spectra, a short introduction to the Fourier series, design of filters, and the properties of the Fourier transform. The focus is on signals rather than power. But the treatment is still pragmatic. For example, the author accepts the work of Butterworth and uses his results to design filters in a fairly methodical fashion. This third of three volumes finishes with a look at spectra by showing how to get a spectrum even if a signal is not periodic. The Fourier transform provides a way of dealing wi

  3. Circuit considerations for repetitive railguns

    Energy Technology Data Exchange (ETDEWEB)

    Honih, E.M.

    1986-01-01

    Railgun electromagnetic launchers have significant military and scientific potential. They provide direct conversion of electrical energy to projectile kinetic energy, and they offer the hope of achieving projectile velocities greatly exceeding the limits of conventional guns. With over 10 km/sec already demonstrated, railguns are attracting attention for tactical and strategic weapons systems and for scientific equation-of-state research. The full utilization of railguns will require significant improvements in every aspect of system design - projectile, barrel, and power source - to achieve operation on a large scale. This paper will review fundamental aspects of railguns, with emphasis on circuit considerations and repetitive operation.

  4. Advanced Microwave Circuits and Systems

    DEFF Research Database (Denmark)

    is usually optimized to have high output power, high efficiency, optimum heat dissipation and high gain. The third part of this book presents power amplifier designs through a series of design examples. Designs undertaken include a switching mode power amplifier, Doherty power amplifier, and flexible power...... such as voltage-controlled oscillators and electron devices for millimeter wave and submillimeter wave applications. This part also covers studies of integrated buffer circuits. Passive components are indispensable elements of any electronic system. The increasing demands to miniaturization and cost effectiveness...

  5. HF radio systems and circuits

    CERN Document Server

    Sabin, William

    1998-01-01

    A comprehensive reference for the design of high frequency communications systems and equipment. This revised edition is loaded with practical data, much of which cannot be found in other reference books. Its approach to the subject follows the needs of an engineer from system definition and performance requirements down to the individual circuit elements that make up radio transmitters and receivers. The accompanying disk contains updated software on filters, matching networks and receiver analysis. SciTech Publishing also provides many other products related to Communication Systems Design.

  6. Radio frequency integrated circuit design

    CERN Document Server

    Rogers, John W M

    2010-01-01

    This newly revised and expanded edition of the 2003 Artech House classic, Radio Frequency Integrated Circuit Design, serves as an up-to-date, practical reference for complete RFIC know-how. The second edition includes numerous updates, including greater coverage of CMOS PA design, RFIC design with on-chip components, and more worked examples with simulation results. By emphasizing working designs, this book practically transports you into the authors' own RFIC lab so you can fully understand the function of each design detailed in this book. Among the RFIC designs examined are RF integrated LC

  7. Circuit for Driving Piezoelectric Transducers

    Science.gov (United States)

    Randall, David P.; Chapsky, Jacob

    2009-01-01

    The figure schematically depicts an oscillator circuit for driving a piezoelectric transducer to excite vibrations in a mechanical structure. The circuit was designed and built to satisfy application-specific requirements to drive a selected one of 16 such transducers at a regulated amplitude and frequency chosen to optimize the amount of work performed by the transducer and to compensate for both (1) temporal variations of the resonance frequency and damping time of each transducer and (2) initially unknown differences among the resonance frequencies and damping times of different transducers. In other words, the circuit is designed to adjust itself to optimize the performance of whichever transducer is selected at any given time. The basic design concept may be adaptable to other applications that involve the use of piezoelectric transducers in ultrasonic cleaners and other apparatuses in which high-frequency mechanical drives are utilized. This circuit includes three resistor-capacitor networks that, together with the selected piezoelectric transducer, constitute a band-pass filter having a peak response at a frequency of about 2 kHz, which is approximately the resonance frequency of the piezoelectric transducers. Gain for generating oscillations is provided by a power hybrid operational amplifier (U1). A junction field-effect transistor (Q1) in combination with a resistor (R4) is used as a voltage-variable resistor to control the magnitude of the oscillation. The voltage-variable resistor is part of a feedback control loop: Part of the output of the oscillator is rectified and filtered for use as a slow negative feedback to the gate of Q1 to keep the output amplitude constant. The response of this control loop is much slower than 2 kHz and, therefore, does not introduce significant distortion of the oscillator output, which is a fairly clean sine wave. The positive AC feedback needed to sustain oscillations is derived from sampling the current through the

  8. Model reduction for circuit simulation

    CERN Document Server

    Hinze, Michael; Maten, E Jan W Ter

    2011-01-01

    Simulation based on mathematical models plays a major role in computer aided design of integrated circuits (ICs). Decreasing structure sizes, increasing packing densities and driving frequencies require the use of refined mathematical models, and to take into account secondary, parasitic effects. This leads to very high dimensional problems which nowadays require simulation times too large for the short time-to-market demands in industry. Modern Model Order Reduction (MOR) techniques present a way out of this dilemma in providing surrogate models which keep the main characteristics of the devi

  9. A Singularity in the Kirchhoff's Circuit Equations

    CERN Document Server

    Harsha, N R Sree

    2016-01-01

    Students often have difficulty in understanding qualitatively the behaviour of simple electric circuits. In particular, as different studies have shown, they find multiple batteries connected in multiple loops difficult to analyse. In a recent paper [Phys. Educ. 50 568 (2015)], we showed such an electric circuit, which consists of ideal batteries connected in parallel, that couldn't be solved by the existing circuit analysis methods. In this paper, we shall introduce a new mathematical method of solving simple electric circuits from the solutions of more general circuits and show that the currents, in this particular circuit, take the indeterminate 0/0 form. We shall also present some of the implications of teaching the method. We believe that the description presented in this paper should help the instructors in teaching the behaviour of multiple batteries connected in parallel.

  10. Physical synthesis of quantum circuits using templates

    Science.gov (United States)

    Mirkhani, Zahra; Mohammadzadeh, Naser

    2016-06-01

    Similar to traditional CMOS circuits, quantum circuit design flow is divided into two main processes: logic synthesis and physical design. Addressing the limitations imposed on optimization of the quantum circuit metrics because of no information sharing between logic synthesis and physical design processes, the concept of "physical synthesis" was introduced for quantum circuit flow, and a few techniques were proposed for it. Following that concept, in this paper a new approach for physical synthesis inspired by template matching idea in quantum logic synthesis is proposed to improve the latency of quantum circuits. Experiments show that by using template matching as a physical synthesis approach, the latency of quantum circuits can be improved by more than 23.55 % on average.

  11. Physical synthesis of quantum circuits using templates

    Science.gov (United States)

    Mirkhani, Zahra; Mohammadzadeh, Naser

    2016-10-01

    Similar to traditional CMOS circuits, quantum circuit design flow is divided into two main processes: logic synthesis and physical design. Addressing the limitations imposed on optimization of the quantum circuit metrics because of no information sharing between logic synthesis and physical design processes, the concept of " physical synthesis" was introduced for quantum circuit flow, and a few techniques were proposed for it. Following that concept, in this paper a new approach for physical synthesis inspired by template matching idea in quantum logic synthesis is proposed to improve the latency of quantum circuits. Experiments show that by using template matching as a physical synthesis approach, the latency of quantum circuits can be improved by more than 23.55 % on average.

  12. Worst Asymmetrical Short-Circuit Current

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Holmstrøm, O; Grastrup, L;

    2010-01-01

    In a typical power plant, the production scenario and the short-circuit time were found for the worst asymmetrical short-circuit current. Then, a sensitivity analysis on the missing generator values was realized in order to minimize the uncertainty of the results. Afterward the worst asymmetrical...... short-circuit current was analyzed in order to compare the results with the allowable DC current component based in the IEC. Finally the normal operating condition for the power plant was modeled....

  13. A Survey of Memristive Threshold Logic Circuits

    OpenAIRE

    Maan, Akshay Kumar; Jayadevi, Deepthi Anirudhan; James, Alex Pappachen

    2016-01-01

    In this paper, we review the different memristive threshold logic (MTL) circuits that are inspired from the synaptic action of flow of neurotransmitters in the biological brain. Brain like generalisation ability and area minimisation of these threshold logic circuits aim towards crossing the Moores law boundaries at device, circuits and systems levels.Fast switching memory, signal processing, control systems, programmable logic, image processing, reconfigurable computing, and pattern recognit...

  14. Monitoring transients in low inductance circuits

    Science.gov (United States)

    Guilford, R.P.; Rosborough, J.R.

    1985-10-21

    The instant invention relates to methods of and apparatus for monitoring transients in low inductance circuits and to a probe utilized to practice said method and apparatus. More particularly, the instant invention relates to methods of and apparatus for monitoring low inductance circuits, wherein the low inductance circuits include a pair of flat cable transmission lines. The instant invention is further directed to a probe for use in monitoring pairs of flat cable transmission lines.

  15. Theory of circuit block switch-off

    OpenAIRE

    S. Henzler; J. Berthold; G. Georgakos; Schmitt-Landsiedel, D.

    2005-01-01

    Switching-off unused circuit blocks is a promising approach to supress static leakage currents in ultra deep sub-micron CMOS digital systems. Basic performance parameters of Circuit Block Switch-Off (CBSO) schemes are defined and their dependence on basic circuit parameters is estimated. Therefore the design trade-off between strong leakage suppression in idle mode and adequate dynamic performance in active mode can be supported by simple analytic investigations. Additionally, a guideline for...

  16. Nonsmooth Modeling and Simulation for Switched Circuits

    CERN Document Server

    Acary, Vincent; Brogliato, Bernard

    2011-01-01

    "Nonsmooth Modeling and Simulation for Switched Circuits" concerns the modeling and the numerical simulation of switched circuits with the nonsmooth dynamical systems (NSDS) approach, using piecewise-linear and multivalued models of electronic devices like diodes, transistors, switches. Numerous examples (ranging from introductory academic circuits to various types of power converters) are analyzed and many simulation results obtained with the INRIA open-source SICONOS software package are presented. Comparisons with SPICE and hybrid methods demonstrate the power of the NSDS approach

  17. The analysis and design of linear circuits

    CERN Document Server

    Thomas, Roland E; Toussaint, Gregory J

    2009-01-01

    The Analysis and Design of Linear Circuits, 6e gives the reader the opportunity to not only analyze, but also design and evaluate linear circuits as early as possible. The text's abundance of problems, applications, pedagogical tools, and realistic examples helps engineers develop the skills needed to solve problems, design practical alternatives, and choose the best design from several competing solutions. Engineers searching for an accessible introduction to resistance circuits will benefit from this book that emphasizes the early development of engineering judgment.

  18. Analog circuit design art, science, and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    Analog Circuit Design: Art, Science, and Personalities discusses the many approaches and styles in the practice of analog circuit design. The book is written in an informal yet informative manner, making it easily understandable to those new in the field. The selection covers the definition, history, current practice, and future direction of analog design; the practice proper; and the styles in analog circuit design. The book also includes the problems usually encountered in analog circuit design; approach to feedback loop design; and other different techniques and applications. The text is

  19. Electric circuit theory applied electricity and electronics

    CERN Document Server

    Yorke, R

    1981-01-01

    Electric Circuit Theory provides a concise coverage of the framework of electrical engineering. Comprised of six chapters, this book emphasizes the physical process of electrical engineering rather than abstract mathematics. Chapter 1 deals with files, circuits, and parameters, while Chapter 2 covers the natural and forced response of simple circuit. Chapter 3 talks about the sinusoidal steady state, and Chapter 4 discusses the circuit analysis. The fifth chapter tackles frequency response of networks, and the last chapter covers polyphase systems. This book will be of great help to electrical

  20. Wafer-scale graphene integrated circuit.

    Science.gov (United States)

    Lin, Yu-Ming; Valdes-Garcia, Alberto; Han, Shu-Jen; Farmer, Damon B; Meric, Inanc; Sun, Yanning; Wu, Yanqing; Dimitrakopoulos, Christos; Grill, Alfred; Avouris, Phaedon; Jenkins, Keith A

    2011-06-10

    A wafer-scale graphene circuit was demonstrated in which all circuit components, including graphene field-effect transistor and inductors, were monolithically integrated on a single silicon carbide wafer. The integrated circuit operates as a broadband radio-frequency mixer at frequencies up to 10 gigahertz. These graphene circuits exhibit outstanding thermal stability with little reduction in performance (less than 1 decibel) between 300 and 400 kelvin. These results open up possibilities of achieving practical graphene technology with more complex functionality and performance.

  1. Hyperchaotic circuit with damped harmonic oscillators

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamasevicius, A.

    2001-01-01

    A simple fourth-order hyperchaotic circuit with damped harmonic oscillators is described. ANP3 and PSpice simulations including an eigenvalue study of the linearized Jacobian are presented together with a hardware implementation. The circuit contains two inductors with series resistance, two ideal...... capacitors and one nonlinear active conductor. The Lyapunov exponents are presented to confirm the hyperchaotic nature of the oscillations of the circuit. The nonlinear conductor is realized with a diode. A negative impedance converter and a linear resistor. The performance of the circuit is investigated...... by means of numerical integration of the appropriate differential equations....

  2. A Survey of Fast Analog Circuit Analysis Algorithm using SPICE

    OpenAIRE

    T.Murugajothi

    2014-01-01

    is paper presents a fast analog circuit analysis algorithm, fundamental circuit-based circuit analysis, for circuits being repeatedly modified and verified in product development. The algorithm reuses previous circuit simulation result on successive changed circuit analysis to achieve simulation operation reduction. The algorithm is implemented with SPICE simulator on linear and nonlinear circuit applications with the proposed device delta models. The experiments show that t...

  3. Short-Circuit Withstand Current Rating for Low Voltage Switchgear : Short-Circuit Current Rating (SCCR)

    OpenAIRE

    Schütt, Matthias

    2016-01-01

    The subject of this thesis was to observe the short-circuit currents at electrical distribution boards. The purpose was to investigate different methods of protecting switchgears from dam-ages caused by short-circuit currents. Manufactures of switchgears need to indicate the rated short-circuit withstand current of their assembly. This thesis is presenting methods of defining the right value of the short-circuit withstand current. This thesis presents theoretical information about the cau...

  4. Towards programmable plant genetic circuits.

    Science.gov (United States)

    Medford, June I; Prasad, Ashok

    2016-07-01

    Synthetic biology enables the construction of genetic circuits with predictable gene functions in plants. Detailed quantitative descriptions of the transfer function or input-output function for genetic parts (promoters, 5' and 3' untranslated regions, etc.) are collected. These data are then used in computational simulations to determine their robustness and desired properties, thereby enabling the best components to be selected for experimental testing in plants. In addition, the process forms an iterative workflow which allows vast improvement to validated elements with sub-optimal function. These processes enable computational functions such as digital logic in living plants and follow the pathway of technological advances which took us from vacuum tubes to cell phones. PMID:27297052

  5. Beta-gamma discriminator circuit

    International Nuclear Information System (INIS)

    The major difficulty encountered in the determination of beta-ray dose in field conditions is generally the presence of a relatively high gamma-ray component. Conventional dosimetry instruments use a shield on the detector to estimate the gamma-ray component in comparison with the beta-ray component. More accurate dosimetry information can be obtained from the measured beta spectrum itself. At Los Alamos, a detector and discriminator circuit suitable for use in a portable spectrometer have been developed. This instrument will discriminate between gammas and betas in a mixed field. The portable package includes a 256-channel MCA which can be programmed to give a variety of outputs, including a spectral display, and may be programmed to read dose directly

  6. Electrical circuit theory and technology

    CERN Document Server

    Bird, John

    2014-01-01

    This much-loved textbook explains the principles of electrical circuit theory and technology so that students of electrical and mechanical engineering can master the subject. Real-world situations and engineering examples put the theory into context. The inclusion of worked problems with solutions help you to learn and further problems then allow you to test and confirm you have fully understood each subject. In total the book contains 800 worked problems, 1000 further problems and 14 revision tests with answers online. This an ideal text for foundation and undergraduate degree students and those on upper level vocational engineering courses, in particular electrical and mechanical. It provides a sound understanding of the knowledge required by technicians in fields such as electrical engineering, electronics and telecommunications. This edition has been updated with developments in key areas such as semiconductors, transistors, and fuel cells, along with brand new material on ABCD parameters and Fourier's An...

  7. Analysis of Short Circuit Transition of Series Capacitor Compensation Device for Electrified Railway%电铁串联电容补偿装置短路过渡过程分析

    Institute of Scientific and Technical Information of China (English)

    魏存祥; 陈飞

    2011-01-01

    介绍了电气化铁道串联电容补偿装置通过穿越性短路电流时,其串补保护设备的工作仿真分析,剖析了外部接触网短路时,流过电容器组、保护间隙、阻尼电阻和电感以及并联断路器的电容器组放电电流和穿越短路电流过渡过程;给出了其串补保护设备主要单元的技术参数。%This article describes the protection device simulation analysis of the electric railway serial capacitor compensation device when passing short-circuit current,analyzes the transition process of the discharge current and the short-circuit current passing capacitors;protective space;damping resistance/inductance and parallel breaker when the OCS short-circuit.In this paper,the main technical parameters of the serial capacitor compensation device is suggested.

  8. Integrated Circuit Electromagnetic Immunity Handbook

    Science.gov (United States)

    Sketoe, J. G.

    2000-08-01

    This handbook presents the results of the Boeing Company effort for NASA under contract NAS8-98217. Immunity level data for certain integrated circuit parts are discussed herein, along with analytical techniques for applying the data to electronics systems. This handbook is built heavily on the one produced in the seventies by McDonnell Douglas Astronautics Company (MDAC, MDC Report E1929 of 1 August 1978, entitled Integrated Circuit Electromagnetic Susceptibility Handbook, known commonly as the ICES Handbook, which has served countless systems designers for over 20 years). Sections 2 and 3 supplement the device susceptibility data presented in section 4 by presenting information on related material required to use the IC susceptibility information. Section 2 concerns itself with electromagnetic susceptibility analysis and serves as a guide in using the information contained in the rest of the handbook. A suggested system hardening requirements is presented in this chapter. Section 3 briefly discusses coupling and shielding considerations. For conservatism and simplicity, a worst case approach is advocated to determine the maximum amount of RF power picked up from a given field. This handbook expands the scope of the immunity data in this Handbook is to of 10 MHz to 10 GHz. However, the analytical techniques provided are applicable to much higher frequencies as well. It is expected however, that the upper frequency limit of concern is near 10 GHz. This is due to two factors; the pickup of microwave energy on system cables and wiring falls off as the square of the wavelength, and component response falls off at a rapid rate due to the effects of parasitic shunt paths for the RF energy. It should be noted also that the pickup on wires and cables does not approach infinity as the frequency decreases (as would be expected by extrapolating the square law dependence of the high frequency roll-off to lower frequencies) but levels off due to mismatch effects.

  9. Manufacture of Lipstick-type ampoule help breaker and safety monitoring of its clinical application%口红式安瓿助断器的研制及其临床应用的安全性监测

    Institute of Scientific and Technical Information of China (English)

    戴琼

    2011-01-01

    [目的]设计一种轻便、灵巧、安全、成本低廉的安瓿助断器,探讨其安全性.[方法]根据玻璃材料的特点是承受压应力很强而承受拉应力却很弱的原理,用不锈钢材料设计制作口红式安瓿助断器,对其使用的安全性及微粒污染情况进行监测.[结果]经6 000次安全性对比试验,无一名护士在使用口红式安瓿助断器折安瓿过程中导致手部受损的发生;经过微粒污染监测试验显示,用口红式安瓿助断器折安瓿微粒污染显著低于临床上常规折安瓿法.[结论]口红式安瓿助断器能有效降低护士玻璃伤发生率,提高护士自我保护能力.%Objective: To design a kind of light, smart, safe, low cost ampoule help breaker, and establish a kind of safe and convenient off - ampoule method. Methods: According to the characteristics of glass which is very weak under stress and broKen in tension,To design lipstick - type ampoule help breaker with stainless steel, and monitor the use safety and particulate pollution. Results: Through 6000 times of security comparative test, no one caused the hand damage in folding the ampoule process by using lipstick - type ampoule help breaker;a test of monitoring particle pollution showed that particulate pollution monitoring by using lipstick- type ampoule help breaker to fold the ampoule was significantly lower than conventional method. Conclusion: The lipstick - type ampoule help breaker can effectively reduce the incidence of glass injuries of nurses and improve the ability to protect themselves.

  10. Analysis of circuits including magnetic cores (MTRAC)

    Science.gov (United States)

    Hanzen, G. R.; Nitzan, D.; Herndon, J. R.

    1972-01-01

    Development of automated circuit analysis computer program to provide transient analysis of circuits with magnetic cores is discussed. Allowance is made for complications caused by nonlinearity of switching core model and magnetic coupling among loop currents. Computer program is conducted on Univac 1108 computer using FORTRAN IV.

  11. Circuits in the Sun: Solar Panel Physics

    Science.gov (United States)

    Gfroerer, Tim

    2013-01-01

    Typical commercial solar panels consist of approximately 60 individual photovoltaic cells connected in series. Since the usual Kirchhoff rules apply, the current is uniform throughout the circuit, while the electric potential of the individual devices is cumulative. Hence, a solar panel is a good analog of a simple resistive series circuit, except…

  12. Sustainability issues in circuit board recycling

    DEFF Research Database (Denmark)

    Legarth, Jens Brøbech; Alting, Leo; Baldo, Gian Luca

    1995-01-01

    The resource recovery and environmental impact issues of printed circuit board recycling by secondary copper smelters are discussed. Guidelines concerning material selection for circuit board manufacture and concerning the recycling processes are given to enhance recovery efficiency and to lower...... the impacts on the external environment from recycling...

  13. CMOS circuits for analog signal processing

    NARCIS (Netherlands)

    Wallinga, Hans

    1988-01-01

    Design choices in CMOS analog signal processing circuits are presented. Special attention is focussed on continuous-time filter technologies. The basics of MOSFET-C continuous-time filters and CMOS Square Law Circuits are explained at the hand of a graphical MOST characteristics representation.

  14. Water quality control program in experimental circuits

    International Nuclear Information System (INIS)

    The Water Quality Control Program of the Experimental Circuits visualizes studying the water chemistry of the cooling in the primary and secondary circuits, monitoring the corrosion of the systems and studying the mechanism of the corrosion products transport in the systems. (author)

  15. POWER MOS FET MODELS FOR "SWITCHING" CIRCUITS

    OpenAIRE

    Rossel, P; Maimouni, R.; Belabadia, M.; Tranduc, Henri; Cordonnier, C.; Bairanzade, M.

    1988-01-01

    A compact model of the Power VDMOS Transistor compatible with the circuit simulator "SPICE2" is described in this article. This model is applied to the simulation of switching circuit with resistive and inductive loads ; comparisons with experimental results are presented.

  16. Memristive circuits simulate memcapacitors and meminductors

    CERN Document Server

    Pershin, Yuriy V

    2009-01-01

    We suggest electronic circuits with memristors (resistors with memory) that operate as memcapacitors (capacitors with memory) and meminductors (inductors with memory). Using a memristor emulator, the suggested circuits have been built and their operation has been demonstrated, showing a useful and interesting connection between the three memory elements.

  17. Automatic Test Pattern Generation for Digital Circuits

    Directory of Open Access Journals (Sweden)

    S. Hemalatha

    2014-04-01

    Full Text Available Digital circuits complexity and density are increasing and at the same time it should have more quality and reliability. It leads with high test costs and makes the validation more complex. The main aim is to develop a complete behavioral fault simulation and automatic test pattern generation (ATPG system for digital circuits modeled in verilog and VHDL. An integrated Automatic Test Generation (ATG and Automatic Test Executing/Equipment (ATE system for complex boards is developed here. An approach to use memristors (resistors with memory in programmable analog circuits. The Main idea consists in a circuit design in which low voltages are applied to memristors during their operation as analog circuit elements and high voltages are used to program the memristor’s states. This way, as it was demonstrated in recent experiments, the state of memristors does not essentially change during analog mode operation. As an example of our approach, we have built several programmable analog circuits demonstrating memristor -based programming of threshold, gain and frequency. In these circuits the role of memristor is played by a memristor emulator developed by us. A multiplexer is developed to generate a class of minimum transition sequences. The entire hardware is realized as digital logical circuits and the test results are simulated in Model sim software. The results of this research show that behavioral fault simulation will remain as a highly attractive alternative for the future generation of VLSI and system-on-chips (SoC.

  18. Verifying Relay Circuits using State Machines

    NARCIS (Netherlands)

    Eijk, P.H.J. van

    2008-01-01

    In this paper we present, illustrate and discuss a number of techniques that can be used in the modelling and verification of electro-mechanical relay circuits. These techniques are based on state machine descriptions of circuits and their functions, and on applying validation tools for properties o

  19. Automatic design of digital synthetic gene circuits.

    Directory of Open Access Journals (Sweden)

    Mario A Marchisio

    2011-02-01

    Full Text Available De novo computational design of synthetic gene circuits that achieve well-defined target functions is a hard task. Existing, brute-force approaches run optimization algorithms on the structure and on the kinetic parameter values of the network. However, more direct rational methods for automatic circuit design are lacking. Focusing on digital synthetic gene circuits, we developed a methodology and a corresponding tool for in silico automatic design. For a given truth table that specifies a circuit's input-output relations, our algorithm generates and ranks several possible circuit schemes without the need for any optimization. Logic behavior is reproduced by the action of regulatory factors and chemicals on the promoters and on the ribosome binding sites of biological Boolean gates. Simulations of circuits with up to four inputs show a faithful and unequivocal truth table representation, even under parametric perturbations and stochastic noise. A comparison with already implemented circuits, in addition, reveals the potential for simpler designs with the same function. Therefore, we expect the method to help both in devising new circuits and in simplifying existing solutions.

  20. IMPORTANT NOTICE: Cancellation of shuttle Circuit 3

    CERN Multimedia

    2013-01-01

    Circuit 3 of the CERN Shuttle Service (Point 5), which has served CMS since the start of LS1, will be cancelled with effect from Tuesday 16 April. This decision has been taken in consultation with CMS, as the circuit was seldom used.   In response to increasing demand for Circuit 1 - Meyrin and feedback from passengers, the two Circuit 3 journeys will be switched to Circuit 1 – Meyrin (see new timetable below): Mornings: Four journeys instead of three. Circuit 1 now starts at 8:10 (instead of 8:19 a.m.) and runs until 9:27 a.m. (instead of 9:16 a.m.). Lunchtimes: Five journeys in place between 12:10 p.m. and 1:47 p.m. Evenings: Circuit starts at 5:23 p.m. (instead of 5:03 p.m.) and ends at 6:20 p.m. at Building 33. Please note that the circuit will depart from Building 13 instead of Building 33.  

  1. Active components for integrated plasmonic circuits

    DEFF Research Database (Denmark)

    Krasavin, A.V.; Bolger, P.M.; Zayats, A.V.;

    2009-01-01

    We present a comprehensive study of highly efficient and compact passive and active components for integrated plasmonic circuit based on dielectric-loaded surface plasmon polariton waveguides.......We present a comprehensive study of highly efficient and compact passive and active components for integrated plasmonic circuit based on dielectric-loaded surface plasmon polariton waveguides....

  2. F-Paris: integrated electronic circuits [Tender

    CERN Multimedia

    2003-01-01

    "Fourniture, montage et tests des circuits imprimes et modules multi composants pour le trajectographe central de CMS. Maximum de 12 000 circuits imprimes et modules multi-composants necessaires au trajectographe central de l'experience CMS aupres du Large Hadron Collider" (1 page).

  3. Post irradiation effects (PIE) in integrated circuits

    International Nuclear Information System (INIS)

    Post Irradiation Effects (PIE) ranging from normal recovery catastrophic failure have been observed in integrated circuits during the PIE period. These variations indicate that a rebound or PIE recipe used for radiation hardness assurance must be chosen with care. In this paper, the authors provide examples of PIE in a variety of integrated circuits of importance to spacecraft electronics

  4. Textbook Error: Short Circuiting on Electrochemical Cell

    Science.gov (United States)

    Bonicamp, Judith M.; Clark, Roy W.

    2007-01-01

    Short circuiting an electrochemical cell is an unreported but persistent error in the electrochemistry textbooks. It is suggested that diagrams depicting a cell delivering usable current to a load be postponed, the theory of open-circuit galvanic cells is explained, the voltages from the tables of standard reduction potentials is calculated and…

  5. Understanding the Behaviour of Infinite Ladder Circuits

    Science.gov (United States)

    Ucak, C.; Yegin, K.

    2008-01-01

    Infinite ladder circuits are often encountered in undergraduate electrical engineering and physics curricula when dealing with series and parallel combination of impedances, as a part of filter design or wave propagation on transmission lines. The input impedance of such infinite ladder circuits is derived by assuming that the input impedance does…

  6. Two New Families of Floating FDNR Circuits

    Directory of Open Access Journals (Sweden)

    Ahmed M. Soliman

    2010-01-01

    Full Text Available Two new configurations for realizing ideal floating frequency-dependent negative resistor elements (FDNR are introduced. The proposed circuits are symmetrical and are realizable by four CCII or ICCII or a combination of both. Each configuration is realizable by eight different circuits. Simulation results are included to support the theory.

  7. Designer's Casebook: current-mode minimax circuit

    NARCIS (Netherlands)

    Wassenaar, Roelof F.

    1992-01-01

    The minimum-maximum (minimax) circuit selects the minimum and maximum of two input currents. Four transistors in matched pairs are operated in the saturation region. Because the behavior of the circuit is based on matched devices and is independent of the relationship between the drain current and t

  8. Delay Reduction in Optimized Reversible Multiplier Circuit

    Directory of Open Access Journals (Sweden)

    Mohammad Assarian

    2012-01-01

    Full Text Available In this study a novel reversible multiplier is presented. Reversible logic can play a significant role in computer domain. This logic can be applied in quantum computing, optical computing processing, DNA computing, and nanotechnology. One condition for reversibility of a computable model is that the number of input equate with the output. Reversible multiplier circuits are the circuits used frequently in computer system. For this reason, optimization in one reversible multiplier circuit can reduce its volume of hardware on one hand and increases the speed in a reversible system on the other hand. One of the important parameters that optimize a reversible circuit is reduction of delays in performance of the circuit. This paper investigates the performance characteristics of the gates, the circuits and methods of optimizing the performance of reversible multiplier circuits. Results showed that reduction of the reversible circuit layers has lead to improved performance due to the reduction of the propagation delay between input and output period. All the designs are in the nanometric scales.

  9. Circuit model for cavity with a port

    International Nuclear Information System (INIS)

    These notes present, by way of an example, the calculation of lumped circuit elements to model a cavity that is connected to a transmission line through a coupling loop. This example is featured in a well-known text. It is adopted here to illustrate the concept and the procedures involved in the calculation of equivalent circuit elements. Its generalization is indicated. (author)

  10. Remote tuning of NMR probe circuits.

    Science.gov (United States)

    Kodibagkar, V D; Conradi, M S

    2000-05-01

    There are many circumstances in which the probe tuning adjustments cannot be located near the rf NMR coil. These may occur in high-temperature NMR, low-temperature NMR, and in the use of magnets with small diameter access bores. We address here circuitry for connecting a fixed-tuned probe circuit by a transmission line to a remotely located tuning network. In particular, the bandwidth over which the probe may be remotely tuned while keeping the losses in the transmission line acceptably low is considered. The results show that for all resonant circuit geometries (series, parallel, series-parallel), overcoupling of the line to the tuned circuit is key to obtaining a large tuning bandwidth. At equivalent extents of overcoupling, all resonant circuit geometries have nearly equal remote tuning bandwidths. Particularly for the case of low-loss transmission line, the tuning bandwidth can be many times the tuned circuit's bandwidth, f(o)/Q. PMID:10783273

  11. Trigger circuits for the PHENIX electromagnetic calorimeter

    International Nuclear Information System (INIS)

    Monolithic and discrete circuits have been developed to provide trigger signals for the PHENIX electromagnetic calorimeter detector. These trigger circuits are deadtimeless and create overlapping 4 by 4 energy sums, a cosmic muon trigger, and a 144 channel energy sum. The front end electronics of the PHENIX system sample the energy and timing channels at each bunch crossing (BC) but it is not known immediately if this data is of interest. The information from the trigger circuits is used to determine if the data collected is of interest and should be digitized and stored or discarded. This paper presents details of the design, issues affecting circuit performance, characterization of prototypes fabricated in 1.2 microm Orbit CMOS, and integration of the circuits into the EMCal electronics system

  12. Depth-optimized reversible circuit synthesis

    Science.gov (United States)

    Arabzadeh, Mona; Saheb Zamani, Morteza; Sedighi, Mehdi; Saeedi, Mehdi

    2013-04-01

    In this paper, simultaneous reduction of circuit depth and synthesis cost of reversible circuits in quantum technologies with limited interaction is addressed. We developed a cycle-based synthesis algorithm which uses negative controls and limited distance between gate lines. To improve circuit depth, a new parallel structure is introduced in which before synthesis a set of disjoint cycles are extracted from the input specification and distributed into some subsets. The cycles of each subset are synthesized independently on different sets of ancillae. Accordingly, each disjoint set can be synthesized by different synthesis methods. Our analysis shows that the best worst-case synthesis cost of reversible circuits in the linear nearest neighbor architecture is improved by the proposed approach. Our experimental results reveal the effectiveness of the proposed approach to reduce cost and circuit depth for several benchmarks.

  13. Grounding and shielding circuits and interference

    CERN Document Server

    Morrison, Ralph

    2016-01-01

    Applies basic field behavior in circuit design and demonstrates how it relates to grounding and shielding requirements and techniques in circuit design This book connects the fundamentals of electromagnetic theory to the problems of interference in all types of electronic design. The text covers power distribution in facilities, mixing of analog and digital circuitry, circuit board layout at high clock rates, and meeting radiation and susceptibility standards. The author examines the grounding and shielding requirements and techniques in circuit design and applies basic physics to circuit behavior. The sixth edition of this book has been updated with new material added throughout the chapters where appropriate. The presentation of the book has also been rearranged in order to reflect the current trends in the field.

  14. Progress in organic integrated circuit manufacture

    Science.gov (United States)

    Taylor, D. Martin

    2016-02-01

    This review article focuses on the development of processes for the manufacture of organic electronic circuits. Beginning with the first report of an organic transistor it highlights the key developments leading to the successful manufacture of microprocessors and other complex circuits incorporating organic transistors. Both batch processing (based on silicon integrated circuit technology) as well as mass-printing, roll-to-roll (R2R) approaches are discussed. Currently, the best circuit performances are achieved using batch processing. It is suggested that an emerging, large mass-market for electronic tags may dictate that R2R manufacture will likely be required to meet the high throughput rates needed. However, significant improvements in resolution and registration are necessary to achieve increased circuit operating speeds.

  15. Low cost design of microprocessor EDAC circuit

    International Nuclear Information System (INIS)

    An optimization method of error detection and correction (EDAC) circuit design is proposed. The method involves selecting or constructing EDAC codes of low cost hardware, associated with operation scheduling implementation based on 2-input XOR gates structure, and two actions for reducing hardware cells, which can reduce the delay penalties and area costs of the EDAC circuit effectively. The 32-bit EDAC circuit hardware implementation is selected to make a prototype, based on the 180 nm process. The delay penalties and area costs of the EDAC circuit are evaluated. Results show that the time penalty and area cost of the EDAC circuitries are affected with different parity-check matrices and different hardware implementation for the EDAC codes with the same capability of correction and detection code. This method can be used as a guide for low-cost radiation-hardened microprocessor EDAC circuit design and for more advanced technologies. (paper)

  16. Light Sources and Ballast Circuits

    Science.gov (United States)

    Yorifuji, Takashi; Sakai, Makoto; Yasuda, Takeo; Maehara, Akiyoshi; Okada, Atsunori; Gouriki, Takeshi; Mannami, Tomoaki

    discharge models were reported. Further, studies on ultra high-pressure mercury lamps as light sources for projectors are becoming the mainstream of HID lamp related researches. For high-pressure sodium lamps, many studies on plant growing and pest control utilizing low insect attracting aspects were also reported in 2006. Additionally, for discharge lamps, the minimum sustaining electric power for arc tubes employed in electrode-less compact fluorescent lamps was investigated. For Hg-free rare-gas fluorescent lamps, a luminance of 10,000cd/m2 was attained by a 1 meter-long external duplex spiral electrode prototype using Xe/Ne barrier discharge. As to startup circuits, the commercialization of energy saving and high value added products mainly associated with fluorescent lamps and HID lamps are becoming common. Further, the miniaturization of startup circuits for self electronic-ballasted lamps has advanced. Speaking of the overall light sources and startup circuits in 2006 and with the enforcement of RoHS in Europe in July, the momentum toward hazardous substance-free and energy saving initiatives has been enhanced from the perspective of protecting the global environment. It is anticipated that similar restrictions will be globally enforced in the future.

  17. Functional molecules in electronic circuits.

    Science.gov (United States)

    Weibel, Nicolas; Grunder, Sergio; Mayor, Marcel

    2007-08-01

    Molecular electronics is a fascinating field of research contributing to both fundamental science and future technological achievements. A promising starting point for molecular devices is to mimic existing electronic functions to investigate the potential of molecules to enrich and complement existing electronic strategies. Molecules designed and synthesized to be integrated into electronic circuits and to perform an electronic function are presented in this article. The focus is set in particular on rectification and switching based on molecular devices, since the control over these two parameters enables the assembly of memory units, likely the most interesting and economic application of molecular based electronics. Both historical and contemporary solutions to molecular rectification are discussed, although not exhaustively. Several examples of integrated molecular switches that respond to light are presented. Molecular switches responding to an electrochemical signal are also discussed. Finally, supramolecular and molecular systems with intuitive application potential as memory units due to their hysteretic switching are highlighted. Although a particularly attractive feature of molecular electronics is its close cooperation with neighbouring disciplines, this article is written from the point of view of a chemist. Although the focus here is largely on molecular considerations, innovative contributions from physics, electro engineering, nanotechnology and other scientific disciplines are equally important. However, the ability of the chemist to correlate function with structure, to design and to provide tailor-made functional molecules is central to molecular electronics. PMID:17637951

  18. Ion implanted dielectric elastomer circuits

    Science.gov (United States)

    O'Brien, Benjamin M.; Rosset, Samuel; Anderson, Iain A.; Shea, Herbert R.

    2013-06-01

    Starfish and octopuses control their infinite degree-of-freedom arms with panache—capabilities typical of nature where the distribution of reflex-like intelligence throughout soft muscular networks greatly outperforms anything hard, heavy, and man-made. Dielectric elastomer actuators show great promise for soft artificial muscle networks. One way to make them smart is with piezo-resistive Dielectric Elastomer Switches (DES) that can be combined with artificial muscles to create arbitrary digital logic circuits. Unfortunately there are currently no reliable materials or fabrication process. Thus devices typically fail within a few thousand cycles. As a first step in the search for better materials we present a preliminary exploration of piezo-resistors made with filtered cathodic vacuum arc metal ion implantation. DES were formed on polydimethylsiloxane silicone membranes out of ion implanted gold nano-clusters. We propose that there are four distinct regimes (high dose, above percolation, on percolation, low dose) in which gold ion implanted piezo-resistors can operate and present experimental results on implanted piezo-resistors switching high voltages as well as a simple artificial muscle inverter. While gold ion implanted DES are limited by high hysteresis and low sensitivity, they already show promise for a range of applications including hysteretic oscillators and soft generators. With improvements to implanter process control the promise of artificial muscle circuitry for soft smart actuator networks could become a reality.

  19. EMI-resilient amplifier circuits

    CERN Document Server

    van der Horst, Marcel J; Linnenbank, André C

    2014-01-01

    This book enables circuit designers to reduce the errors introduced by the fundamental limitations and electromagnetic interference (EMI) in negative-feedback amplifiers.  The authors describe a systematic design approach for application specific negative-feedback amplifiers, with specified signal-to-error ratio (SER).  This approach enables designers to calculate noise, bandwidth, EMI, and the required bias parameters of the transistors used in  application specific amplifiers in order to meet the SER requirements.   ·         Describes design methods that incorporate electromagnetic interference (EMI) in the design of application specific negative-feedback amplifiers; ·         Provides designers with a structured methodology to avoid the use of trial and error in meeting signal-to-error ratio (SER) requirements; ·         Equips designers to increase EMI immunity of the amplifier itself, thus avoiding filtering at the input, reducing the number of components and avoiding detr...

  20. Brainstem Circuits Regulating Gastric Function

    Science.gov (United States)

    Travagli, R. Alberto; Hermann, Gerlinda E.; Browning, Kirsteen N.; Rogers, Richard C.

    2011-01-01

    Brainstem parasympathetic circuits that modulate digestive functions of the stomach are comprised of afferent vagal fibers, neurons of the nucleus tractus solitarius (NTS), and the efferent fibers originating in the dorsal motor nucleus of the vagus (DMV). A large body of evidence has shown that neuronal communications between the NTS and the DMV are plastic and are regulated by the presence of a variety of neurotransmitters and circulating hormones as well as the presence, or absence, of afferent input to the NTS. These data suggest that descending central nervous system inputs as well as hormonal and afferent feedback resulting from the digestive process can powerfully regulate vago-vagal reflex sensitivity. This paper first reviews the essential “static” organization and function of vago-vagal gastric control neurocircuitry. We then present data on the opioidergic modulation of NTS connections with the DMV as an example of the “gating” of these reflexes, i.e., how neurotransmitters, hormones, and vagal afferent traffic can make an otherwise static autonomic reflex highly plastic. PMID:16460274

  1. Microcontroller based Integrated Circuit Tester

    Directory of Open Access Journals (Sweden)

    Yousif Taha Yousif Elamin

    2015-02-01

    Full Text Available The digital integrated circuit (IC tester is implemented by using the ATmega32 microcontroller . The microcontroller processes the inputs and outputs and displays the results on a Liquid Crystal Display (LCD. The basic function of the digital IC tester is to test a digital IC for correct logical functioning as described in the truth table and/or function table. The designed model can test digital ICs having 14 pins. Since it is programmable, any number of ICs can be tested . This model applies the necessary signals to the inputs of the IC, monitoring the outputs at each stage and comparing them with the outputs in the truth table. Any discrepancy in the functioning of the IC results in a fail indication, displays the faulty and good gates on the LCD. The testing procedure is accomplished with the help of keypad keys present on the main board design. The test has been accomplished with most commonly used digital IC's, mainly belonging to the 74 series. Digital IC tester tests three samples of IC's ( NAND, NOT, NOR. The design is flexible . We can add extra IC bases and subroutines to test any other IC in the 74 series.

  2. 49 CFR 236.720 - Circuit, common return.

    Science.gov (United States)

    2010-10-01

    ... Circuit, common return. A term applied where one wire is used for the return of more than one electric circuit. ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, common return. 236.720 Section...

  3. Visualization of circuit card electromagnetic fields

    Science.gov (United States)

    Zwillinger, Daniel

    1995-01-01

    Circuit boards are used in nearly every electrical appliance. Most board failures cause differing currents in the circuit board traces and components. This causes the circuit board to radiate a differing electromagnetic field. Imaging this radiated field, which is equivalent to measuring the field, could be used for error detection. Using estimates of the fields radiated by a low power digital circuit board, properties of known materials, and available equipment, we determined how well the following technologies could be used to visualize circuit board electromagnetic fields (prioritized by promise): electrooptical techniques, magnetooptical techniques, piezoelectric techniques, thermal techniques, and electrodynamic force technique. We have determined that sensors using the electrooptical effect (Pockels effect) appear to be sufficiently sensitive for use in a circuit board imaging system. Sensors utilizing the magnetooptical effect may also be adequate for this purpose, when using research materials. These sensors appear to be capable of achieving direct broadband measurements. We also reviewed existing electromagnetic field sensors. Only one of the sensors (recently patented) was specifically designed for circuit board measurements.

  4. Performance Analysis of Modified QSERL Circuit

    Directory of Open Access Journals (Sweden)

    Shipra Upadhyay

    2013-08-01

    Full Text Available This work is based on a new approach for minimizing energy consumption in quasi static energy recoverylogic (QSERL circuit which involves optimization by removing the non adiabatic losses completely.Energy recovering circuitry based on adiabatic principles is a promising technique leading towards lowpowerhigh performance circuit design. The efficiency of such circuits may be increased by reducing theadiabatic and non-adiabatic losses drawn by them during the charging and recovery operations. In thispaper, performance of the proposed logic style is analyzed and compared with CMOS in theirrepresentative inverters, gates, flip flops and adder circuits. All the circuits were simulated by VIRTUOSOSPECTRE simulator of Cadence in 0.18μm technology. In our proposed inverter the energy efficiency hasbeen improved to almost 30% & 20% upto 20MHz and 20fF external load capacitance in comparison toCMOS & QSERL circuits respectively. Our proposed circuit provides energy efficient performance up to100 MHz and thus it has proven to be used in high-performance VLSI circuitry.

  5. 高压断路器气流场有限体积及TVD格式法的研究%Study on Finite Volume Method and TVD Scheme for Calculating the Flow Field of High Voltage Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    曹云东; 王尔智

    2002-01-01

    将有限体积法与TVD格式相结合对高压断路器气流场的计算进行了深入的研究.根据SF6断路器流路复杂、固壁形式多样、动触头高速运动的特点,本文采用区域分解、滑移网格连续移动、数据实时传递等技术,消除了传统网格滑移中计算时间、步长变化的各种限制,实现了计算时间的微量变化,很好地解决了传统方法中网格生成存在的各种问题,形成了高分辨率、高精度断路器流场计算的一整套新方法.

  6. RELIABLE OPERATIONAL MEASURES OF OUTDOOR SF6 CIRCUIT BREAKER AT INCLEMENT AREAS%户外SF6断路器在严寒地区可靠运行的措施

    Institute of Scientific and Technical Information of China (English)

    刘彦军; 李松琴

    2001-01-01

    由于SF6气体在超低温下产生部分液化,使得断路器内的SF6气体密度下降,降低了断路器的开断能力和绝缘水平;为此,提出了采用混合气体,或者采用加热SF6气体的方法,以解决高压SF6断路器在严寒地区能够可靠运行的问题.

  7. Causes Analysis of Circuit Breaker Malfunction in Low Voltage AC Cubicle Switchboard in Niangziguan Section Post%娘子关分区所低压交流柜断路器误动原因分析

    Institute of Scientific and Technical Information of China (English)

    冯巨祥

    2009-01-01

    对娘子关分区所低压交流柜断路器误动原因进行了分析,找出了低压断路器因高次谐波误动的原因,提出了问题的解决方案,并予以实施,取得了较好的效果.

  8. Application of SF6 Decomposition Products Test in 330kV Circuit Breaker Troubleshooting%SF6分解产物测试在330kV断路器故障排除中的应用

    Institute of Scientific and Technical Information of China (English)

    陈宏刚; 温定筠; 秦睿; 孙亚明; 王斌

    2015-01-01

    本文对一起典型的断路器SF6分解产物异常进行了研究分析.通过对断路器内部的测试分析,发现了设备重大安全隐患,确保了设备的运行安全,是一起SF6气体标志性分解产物发现设备内部故障的典型案例.对充SF6气体设备的运行、维护及试验检测具有借鉴意义.

  9. Reversible and quantum circuits optimization and complexity analysis

    CERN Document Server

    Abdessaied, Nabila

    2016-01-01

    This book presents a new optimization flow for quantum circuits realization. At the reversible level, optimization algorithms are presented to reduce the quantum cost. Then, new mapping approaches to decompose reversible circuits to quantum circuits using different quantum libraries are described. Finally, optimization techniques to reduce the quantum cost or the delay are applied to the resulting quantum circuits. Furthermore, this book studies the complexity of reversible circuits and quantum circuits from a theoretical perspective.

  10. Short-circuit forces in power lines and substations.

    OpenAIRE

    Lilien, Jean-Louis; Goel, Anand

    2009-01-01

    This chapter discusses short-circuit oscillations in power lines. Short-circuit currents generate electromagnetic forces on the conductors, exciting short-circuit oscillations. Since the short-circuit periods are very short, the short-circuit forces in single conductor overhead lines are usually low because of the large phase spacing. However these forces may have considerable impact on distribution lines due to the change in phase spacing during short-circuit occurrences. For bundle conducto...

  11. 75 FR 22043 - Airworthiness Directives; Agusta S.p.A. (Agusta) Model A109E Helicopters

    Science.gov (United States)

    2010-04-27

    ... of the 35 Amps BATT BUS circuit breaker. To prevent an electrical failure, the manufacturer has... BUS circuit breaker installation. The service information specifies modifying the fuselage electrical... electrical installation, P/N 109-0741-55 with a BATT BUS circuit breaker modification kit, P/N...

  12. 75 FR 61341 - Airworthiness Directives; Agusta S.p.A. (Agusta) Model A109E Helicopters

    Science.gov (United States)

    2010-10-05

    ... of the 35 Amps BATT BUS circuit breaker. To prevent an electrical failure, the manufacturer has...-49, and the overhead panel electrical installation, P/N 109-0741-55, with a BATT BUS circuit breaker... overhead panel electrical installation, P/N 109-0741-55 with a BATT BUS circuit breaker modification kit,...

  13. Equivalent circuit analysis of terahertz metamaterial filters

    KAUST Repository

    Zhang, Xueqian

    2011-01-01

    An equivalent circuit model for the analysis and design of terahertz (THz) metamaterial filters is presented. The proposed model, derived based on LMC equivalent circuits, takes into account the detailed geometrical parameters and the presence of a dielectric substrate with the existing analytic expressions for self-inductance, mutual inductance, and capacitance. The model is in good agreement with the experimental measurements and full-wave simulations. Exploiting the circuit model has made it possible to predict accurately the resonance frequency of the proposed structures and thus, quick and accurate process of designing THz device from artificial metamaterials is offered. ©2011 Chinese Optics Letters.

  14. Multi-qubit circuit quantum electrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Viehmann, Oliver

    2013-09-03

    Circuit QED systems are macroscopic, man-made quantum systems in which superconducting artificial atoms, also called Josephson qubits, interact with a quantized electromagnetic field. These systems have been devised to mimic the physics of elementary quantum optical systems with real atoms in a scalable and more flexible framework. This opens up a variety of possible applications of circuit QED systems. For instance, they provide a promising platform for processing quantum information. Recent years have seen rapid experimental progress on these systems, and experiments with multi-component circuit QED architectures are currently starting to come within reach. In this thesis, circuit QED systems with multiple Josephson qubits are studied theoretically. We focus on simple and experimentally realistic extensions of the currently operated circuit QED setups and pursue investigations in two main directions. First, we consider the equilibrium behavior of circuit QED systems containing a large number of mutually noninteracting Josephson charge qubits. The currently accepted standard description of circuit QED predicts the possibility of superradiant phase transitions in such systems. However, a full microscopic treatment shows that a no-go theorem for superradiant phase transitions known from atomic physics applies to circuit QED systems as well. This reveals previously unknown limitations of the applicability of the standard theory of circuit QED to multi-qubit systems. Second, we explore the potential of circuit QED for quantum simulations of interacting quantum many-body systems. We propose and analyze a circuit QED architecture that implements the quantum Ising chain in a time-dependent transverse magnetic field. Our setup can be used to study quench dynamics, the propagation of localized excitations, and other non-equilibrium features in this paradigmatic model in the theory of non-equilibrium thermodynamics and quantumcritical phenomena. The setup is based on a

  15. The Drosophila melanogaster circadian pacemaker circuit

    Indian Academy of Sciences (India)

    Vasu Sheeba

    2008-12-01

    As an experimental model system, the fruit fly Drosophila melanogaster has been seminal in shaping our understanding of the circadian clockwork. The wealth of genetic tools at our disposal over the past four decades has enabled discovery of the genetic and molecular bases of circadian rhythmicity. More recently, detailed investigation leading to the anatomical, neurochemical and electrophysiological characterization of the various neuronal subgroups that comprise the circadian machinery has revealed pathways through which these neurons come together to act as a neuronal circuit. Thus the D. melanogaster circadian pacemaker circuit presents a relatively simple and attractive model for the study of neuronal circuits and their functions.

  16. Some results on uniform arithmetic circuit complexity

    DEFF Research Database (Denmark)

    Frandsen, Gudmund Skovbjerg; Valence, Mark; Barrington, David A. Mix

    1994-01-01

    and polynomial-size unbounded fan-in arithmetic circuits satisfying a natural uniformity constraint (DLOGTIME-uniformity). A 1-input and 1-output arithmetic function over the fieldsF2n may be identified with ann-input andn-output Boolean function when field elements are represented as bit strings. We prove...... that if some such representation is X-uniform (where X is P or DLOGTIME), then the arithmetic complexity of a function (measured with X-uniform unbounded fan-in arithmetic circuits) is identical to the Boolean complexity of this function (measured with X-uniform threshold circuits). We show the existence...

  17. Circuits with arbitrary gates for random operators

    OpenAIRE

    Jukna, S.; Schnitger, G.

    2010-01-01

    We consider boolean circuits computing n-operators f:{0,1}^n --> {0,1}^n. As gates we allow arbitrary boolean functions; neither fanin nor fanout of gates is restricted. An operator is linear if it computes n linear forms, that is, computes a matrix-vector product y=Ax over GF(2). We prove the existence of n-operators requiring about n^2 wires in any circuit, and linear n-operators requiring about n^2/\\log n wires in depth-2 circuits, if either all output gates or all gates on the middle laye...

  18. Operational amplifier circuits analysis and design

    CERN Document Server

    Nelson, J C C

    1995-01-01

    This book, a revised and updated version of the author's Basic Operational Amplifiers (Butterworths 1986), enables the non-specialist to make effective use of readily available integrated circuit operational amplifiers for a range of applications, including instrumentation, signal generation and processing.It is assumed the reader has a background in the basic techniques of circuit analysis, particularly the use of j notation for reactive circuits, with a corresponding level of mathematical ability. The underlying theory is explained with sufficient but not excessive, detail. A range of compu

  19. An introduction to logic circuit testing

    CERN Document Server

    Lala, Parag K

    2008-01-01

    An Introduction to Logic Circuit Testing provides a detailed coverage of techniques for test generation and testable design of digital electronic circuits/systems. The material covered in the book should be sufficient for a course, or part of a course, in digital circuit testing for senior-level undergraduate and first-year graduate students in Electrical Engineering and Computer Science. The book will also be a valuable resource for engineers working in the industry. This book has four chapters. Chapter 1 deals with various types of faults that may occur in very large scale integration (VLSI)

  20. Theory of circuit block switch-off

    Directory of Open Access Journals (Sweden)

    S. Henzler

    2004-01-01

    Full Text Available Switching-off unused circuit blocks is a promising approach to supress static leakage currents in ultra deep sub-micron CMOS digital systems. Basic performance parameters of Circuit Block Switch-Off (CBSO schemes are defined and their dependence on basic circuit parameters is estimated. Therefore the design trade-off between strong leakage suppression in idle mode and adequate dynamic performance in active mode can be supported by simple analytic investigations. Additionally, a guideline for the estimation of the minimum time for which a block deactivation is useful is derived.