Wang, Hao; Zhang, Fengge; Guan, Tao; Yu, Siyang
2017-09-01
A brushless electrically excited synchronous generator (BEESG) with a hybrid rotor is a novel electrically excited synchronous generator. The BEESG proposed in this paper is composed of a conventional stator with two different sets of windings with different pole numbers, and a hybrid rotor with powerful coupling capacity. The pole number of the rotor is different from those of the stator windings. Thus, an analysis method different from that applied to conventional generators should be applied to the BEESG. In view of this problem, the equivalent circuit and electromagnetic torque expression of the BEESG are derived on the basis of electromagnetic relation of the proposed generator. The generator is simulated and tested experimentally using the established equivalent circuit model. The experimental and simulation data are then analyzed and compared. Results show the validity of the equivalent circuit model.
Brushless exciters using a high temperature superconducting field winding
Garces, Luis Jose [Schenectady, NY; Delmerico, Robert William [Clifton Park, NY; Jansen, Patrick Lee [Scotia, NY; Parslow, John Harold [Scotia, NY; Sanderson, Harold Copeland [Tribes Hill, NY; Sinha, Gautam [Chesterfield, MO
2008-03-18
A brushless exciter for a synchronous generator or motor generally includes a stator and a rotor rotatably disposed within the stator. The rotor has a field winding and a voltage rectifying bridge circuit connected in parallel to the field winding. A plurality of firing circuits are connected the voltage rectifying bridge circuit. The firing circuit is configured to fire a signal at an angle of less than 90.degree. or at an angle greater than 90.degree.. The voltage rectifying bridge circuit rectifies the AC voltage to excite or de-excite the field winding.
Integrated-Circuit Controller For Brushless dc Motor
Le, Dong Tuan
1994-01-01
Generic circuit performs commutation-logic and power-switching functions for control of brushless dc motor. Controller includes commutation-logic and associated control circuitry, power supply, and inverters containing power transistors. Major advantages of controller are size, weight, and power consumption can be made less than other brushless-dc-motor controllers.
Application brushless machines with combine excitation for a hybrid car and an electric car
Gandzha S.A.; Kiessh I.E.
2015-01-01
This article shows advantages of application the brushless machines with combined excitation (excitation from permanent magnets and excitation winding) for the hybrid car and the electric car. This type of electric machine is compared with a typical brushless motor and an induction motor. The main advantage is the decrease of the dimensions of electric machine and the reduction of the price for an electronic control system. It is shown the design and the principle of operation of the electric...
Application brushless machines with combine excitation for a hybrid car and an electric car
Directory of Open Access Journals (Sweden)
Gandzha S.A.
2015-08-01
Full Text Available This article shows advantages of application the brushless machines with combined excitation (excitation from permanent magnets and excitation winding for the hybrid car and the electric car. This type of electric machine is compared with a typical brushless motor and an induction motor. The main advantage is the decrease of the dimensions of electric machine and the reduction of the price for an electronic control system. It is shown the design and the principle of operation of the electric machine. The machine was modeled using Solidworks program for creating design and Maxwell program for the magnetic field analysis. The result of tests is shown as well.
Development of a brushless HTS exciter for a 10 kW HTS synchronous generator
Bumby, Chris W.; Badcock, Rodney A.; Sung, Hae-Jin; Kim, Kwang-Min; Jiang, Zhenan; Pantoja, Andres E.; Bernardo, Patrick; Park, Minwon; Buckley, Robert G.
2016-02-01
HTS synchronous generators, in which the rotor coils are wound from high-T c superconducting wire, are exciting attention due to their potential to deliver very high torque and power densities. However, injection of the large DC currents required by the HTS rotor coils presents a technical challenge. In this paper we discuss the development of a brushless HTS exciter which operates across the cryostat wall to inject a superconducting DC current into the rotor coil circuit. This approach fundamentally alters the thermal load upon the cryogenic system by removing the need for thermally inefficient normal-conducting current leads. We report results from an experimental laboratory device and show that it operates as a constant voltage source with an effective internal resistance. We then discuss the design of a prototype HTS-PM exciter based on our experimental device, and describe its integration with a demonstration HTS generator. This 200 RPM, 10 kW synchronous generator comprises eight double pancake HTS rotor coils which are operated at 30 K, and are energised to 1.5 T field through the injection of 85 A per pole. We show how this excitation can be achieved using an HTS-PM exciter consisting of 12 stator poles of 12 mm YBCO coated-conductor wire and an external permanent magnet rotor. We demonstrate that such an exciter can excite the rotor windings of this generator without forming a thermal-bridge across the cryostat wall. Finally, we provide estimates of the thermal load imposed by our prototype HTS-PM exciter on the rotor cryostat. We show that duty cycle operation of the device ensures that this heat load can be minimised, and that it is substantially lower than that of equivalently-rated conventional current leads.
Reversible thyristor converters of brushless synchronous compensators
Directory of Open Access Journals (Sweden)
А.М.Galynovskiy
2013-12-01
Full Text Available Behavior of models of three-phase-to-single-phase rotary reversible thyristor converters of brushless synchronous compensators in a circuit simulation system is analyzed. It is shown that combined control mode of opposite-connected thyristors may result in the exciter armature winding short circuits both at the thyristor feed-forward and lagging current delay angles. It must be taken into consideration when developing brushless compensator excitation systems.
Computer Simulation of a Three-phase Brushless Self-Excited Synchronous Generator
Cingoski, Vlatko; Mikami, Mitsuru; Yamashita, Hideo
1999-01-01
Computer simulation of the operating characteristics of a three-phase brushless synchronous generator with self-excited is presented. A voltage driven nonlinear time-periodic FEA is utilized to compute accurately the magnetic field distribution and the induced voltage and currents simultaneously.
Influence of Voltage Dips on the Operation of Brushless Exciter System of Synchronous Machines
Directory of Open Access Journals (Sweden)
Fedotov A.
2016-06-01
Full Text Available This paper presents a mathematical model with continuous variables for brushless exciter system of synchronous machines, containing the thyristor elements. Discrete Laplace transform is used for transition from a mathematical model of a system with variable structure in continuous variables to equation finite difference with permanent structure. Then inverse transition is made to a mathematical model in continuous variables with permanent structure.
Yingchao Zhang
2012-01-01
In this paper, a novel doubly excited brushless generator (DEBG) with outer radial laminated magnetic barrier rotor (RLMB-rotor) for wind power application was designed and analyzed. The DEBG has 10 rotor pole numbers with outer rotor. Its performance is investigated using the 2D transient finite element method. The magnetic fields, torque capability, end winding voltage characteristics, radial magnetic force and energy efficiency were analyzed. All studies in this paper show that the simplic...
16,000-rpm Interior Permanent Magnet Reluctance Machine with Brushless Field Excitation
Energy Technology Data Exchange (ETDEWEB)
Hsu, J.S.; Burress, T.A.; Lee, S.T.; Wiles, R.H.; Coomer, C.L.; McKeever, J.W.; Adams, D.J.
2007-10-31
The reluctance interior permanent magnet (RIPM) motor is currently used by many leading auto manufacturers for hybrid vehicles. The power density for this type of motor is high compared with that of induction motors and switched reluctance motors. The primary drawback of the RIPM motor is the permanent magnet (PM) because during high-speed operation, the fixed PM produces a huge back electromotive force (emf) that must be reduced before the current will pass through the stator windings. This reduction in back-emf is accomplished with a significant direct-axis (d-axis) demagnetization current, which opposes the PM's flux to reduce the flux seen by the stator wires. This may lower the power factor and efficiency of the motor and raise the requirement on the alternate current (ac) power supply; consequently, bigger inverter switching components, thicker motor winding conductors, and heavier cables are required. The direct current (dc) link capacitor is also affected when it must accommodate heavier harmonic currents. It is commonly agreed that, for synchronous machines, the power factor can be optimized by varying the field excitation to minimize the current. The field produced by the PM is fixed and cannot be adjusted. What can be adjusted is reactive current to the d-axis of the stator winding, which consumes reactive power but does not always help to improve the power factor. The objective of this project is to avoid the primary drawbacks of the RIPM motor by introducing brushless field excitation (BFE). This offers both high torque per ampere (A) per core length at low speed by using flux, which is enhanced by increasing current to a fixed excitation coil, and flux, which is weakened at high speed by reducing current to the excitation coil. If field weakening is used, the dc/dc boost converter used in a conventional RIPM motor may be eliminated to reduce system costs. However, BFE supports a drive system with a dc/dc boost converter, because it can further
Four quadrant control circuit for a brushless three-phase dc motor
Nola, Frank J. (Inventor)
1987-01-01
A control circuit is provided for a brushless three-phase dc motor which affords four quadrant control from a single command. The control circuit probes acceleration of the motor in both clockwise and counterclockwise directions and braking and generation in both clockwise and counterclockwise directions. In addition to turning on individual transistors of the transistor pairs connected to the phase windings of the motor for 120 deg periods while the other transistor of that pair is off, the control circuit also provides, in a future mode of operation, turning the two transistors of each pair on and off alternately at a phase modulation frequency during such a 120 deg period. A feedback signal is derived which is proportional to the motor current and which has a polarity consistent with the command signal, such that negative feedback results.
Directory of Open Access Journals (Sweden)
Yingchao Zhang
2012-09-01
Full Text Available In this paper, a novel doubly excited brushless generator (DEBG with outer radial laminated magnetic barrier rotor (RLMB-rotor for wind power application was designed and analyzed. The DEBG has 10 rotor pole numbers with outer rotor. Its performance is investigated using the 2D transient finite element method. The magnetic fields, torque capability, end winding voltage characteristics, radial magnetic force and energy efficiency were analyzed. All studies in this paper show that the simplicity, reliability, high efficiency and low vibration and noise of the DEBG with outer rotor are attractive for variable speed constant frequency (VSCF wind power generation system.
New Logic Circuit with DC Parametric Excitation
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.
Energy Technology Data Exchange (ETDEWEB)
Shibata, F.; Fukami, T. (Kanazawa Institute of Technology, Ishikawa (Japan))
1992-08-15
In this paper, configuration of a brushless three-phase synchronous motor with no exciter is proposed. The applied technique is effective to simplify the conventional brushless synchronous motor configuration. A stator of the motor is equipped with a double-star connected armature winding with two neutral points for DC exciting. A cylindrical stator is equipped with a two-phase field winding, which is connected with shaft-mounted rectifiers. During the operation of the motor at synchronous speed, DC voltage is applied to the two neutral points of the armature winding for excitation of the rotor. At that time, the armature winding acts as a stator DC exciting winding and a load winding. This paper describes the principle and the characteristic analysis of the new motor as well as the experimental results of the 2kW test-motor. The experimental results almost agree with the analytical results, so that the favorable performance characteristics of the proposed motor were confirmed. For instance, the power factor of this motor can be controlled in a wide range by adjusting the stator DC exciting current. 9 refs., 8 figs., 1 tab.
Tachometers Derived From a Brushless DC Motor
Howard, David E.; Smith, Dennis A.
2007-01-01
The upper part of the figure illustrates the major functional blocks of a direction-sensitive analog tachometer circuit based on the use of an unexcited two-phase brushless dc motor as a rotation transducer. The primary advantages of this circuit over many older tachometer circuits include the following: Its output inherently varies linearly with the rate of rotation of the shaft. Unlike some tachometer circuits that rely on differentiation of voltages with respect to time, this circuit relies on integration, which results in signals that are less noisy. There is no need for an additional shaft-angle sensor, nor is there any need to supply electrical excitation to a shaft-angle sensor. There is no need for mechanical brushes (which tend to act as sources of electrical noise). The underlying concept and electrical design are relatively simple. This circuit processes the back-electromagnetic force (back-emf) outputs of the two motor phases into a voltage directly proportional to the instantaneous rate (sign magnitude) of rotation of the shaft. The processing in this circuit effects a straightforward combination of mathematical operations leading to a final operation based on the well-known trigonometric identity (sin x)2 + (cos x)2 = 1 for any value of x. The principle of operation of this circuit is closely related to that of the tachometer circuit described in Tachometer Derived From Brushless Shaft-Angle Resolver (MFS-28845), NASA Tech Briefs, Vol. 19, No. 3 (March 1995), page 39. However, the present circuit is simpler in some respects because there is no need for sinusoidal excitation of shaftangle- resolver windings.
Dual Brushless Resolver Rate Sensor
Howard, David E. (Inventor)
1997-01-01
A resolver rate sensor is disclosed in which dual brushless resolvers are mechanically coupled to the same output shaft. Diverse inputs are provided to each resolver by providing the first resolver with a DC input and the second resolver with an AC sinusoidal input. A trigonometric identity in which the sum of the squares of the sin and cosine components equal one is used to advantage in providing a sensor of increased accuracy. The first resolver may have a fixed or variable DC input to permit dynamic adjustment of resolver sensitivity thus permitting a wide range of coverage. In one embodiment of the invention the outputs of the first resolver are directly inputted into two separate multipliers and the outputs of the second resolver are inputted into the two separate multipliers, after being demodulated in a pair of demodulator circuits. The multiplied signals are then added in an adder circuit to provide a directional sensitive output. In another embodiment the outputs from the first resolver is modulated in separate modulator circuits and the output from the modulator circuits are used to excite the second resolver. The outputs from the second resolver are demodulated in separate demodulator circuit and added in an adder circuit to provide a direction sensitive rate output.
Initial Rotor Position Estimation of Half-Wave Rectified Brushless Synchronous Motor
Abe, Takashi; Oyama, Jun; Higuchi, Tsuyoshi
This paper presents an initial rotor position estimation of Half-Wave Rectified Brushless Synchronous Motor. In the previous paper, we proposed this motor as AC servo motor, which is based on the half-wave rectified brushless excitation principle. The basic principle of this estimation technique utilizes the dependence of inductance on the rotor position. The bias frequency component of half-Wave rectified brushless excitation is used to estimate the rotor position error. The magnetic pole is discriminated by the switching condition of the diode inserted into the rotor field winding. This estimation technique is confirmed by simulation include inverter circuit, control program and motor model. Finally, the effectiveness of the proposed estimation technique has been verified by experiments.
An improved RF circuit for Overhauser magnetometer excitation
Zheng, Di; Zhang, Shuang; Guo, Xin; Fu, Haoyang
2015-08-01
Overhauser magnetometer is a high-precision device for magnetostatic field measurement, which can be used in a wide variety of purposes: UXO detection, pipeline mapping and other engineering and environmental applications. Traditional proton magnetometer adopts DC polarization, suffering from low polarization efficiency, high power consumption and low signal noise ratio (SNR). Compared with the traditional proton magnetometer, nitroxide free radicals are used for dynamic nuclear polarization (DNP) to enhance nuclear magnetic resonance (NMR). RF excitation is very important for electron resonance in nitrogen oxygen free radical solution, and it is primarily significant for the obtention of high SNR signal and high sensitive field observation. Therefore, RF excitation source plays a crucial role in the development of Overhauser magnetometer. In this paper, an improved design of a RF circuit is discussed. The new RF excitation circuit consists of two parts: Quartz crystal oscillator circuit and RF power amplifier circuit. Simulation and optimization designs for power amplifier circuit based on software ADS are presented. Finally we achieve a continuous and stable sine wave of 60MHz with 1-2.5 W output power, and the second harmonic suppression is close to -20dBc. The improved RF circuit has many merits such as small size, low-power consumption and high efficiency, and it can be applied to Overhauser magnetometer to obtain high sensitive field observation.
Renovating the excitation circuit of a conventional welding converter
Indian Academy of Sciences (India)
This paper presents two different new excitation current supplies based on power electronics for an existing conventional welding converter. The proposed circuits are simulated using Lab-VIEW 1200 AI and a PC based system. In the expressions for winding currents the dynamic inductances are used to take into account ...
Effects of cell cycle noise on excitable gene circuits
Veliz-Cuba, Alan; Bennett, Matthew R; Josić, Krešimir; Ott, William
2016-01-01
We assess the impact of cell cycle noise on gene circuit dynamics. For bistable genetic switches and excitable circuits, we find that transitions between metastable states most likely occur just after cell division and that this concentration effect intensifies in the presence of transcriptional delay. We explain this concentration effect with a 3-states stochastic model. For genetic oscillators, we quantify the temporal correlations between daughter cells induced by cell division. Temporal correlations must be captured properly in order to accurately quantify noise sources within gene networks.
Magnetic equivalent circuit model for unipolar hybrid excitation synchronous machine
Directory of Open Access Journals (Sweden)
Kupiec Emil
2015-03-01
Full Text Available Lately, there has been increased interest in hybrid excitation electrical machines. Hybrid excitation is a construction that combines permanent magnet excitation with wound field excitation. Within the general classification, these machines can be classified as modified synchronous machines or inductor machines. These machines may be applied as motors and generators. The complexity of electromagnetic phenomena which occur as a result of coupling of magnetic fluxes of separate excitation systems with perpendicular magnetic axis is a motivation to formulate various mathematical models of these machines. The presented paper discusses the construction of a unipolar hybrid excitation synchronous machine. The magnetic equivalent circuit model including nonlinear magnetization curves is presented. Based on this model, it is possible to determine the multi-parameter relationships between the induced voltage and magnetomotive force in the excitation winding. Particular attention has been paid to the analysis of the impact of additional stator and rotor yokes on above relationship. Induced voltage determines the remaining operating parameters of the machine, both in the motor and generator mode of operation. The analysis of chosen correlations results in an identification of the effective control range of electromotive force of the machine.
Simplified Model of Brushless Synchronous Generator for Real Time Simulation
Lopez, M D; Rebollo, E; Blanquez, F R
2015-01-01
This paper presents a simplified model of brushless synchronous machine for saving hardware resources in a real time simulation system. Firstly, a brushless excitation system model is described. Thereafter, the simplified transfer function of an AC exciter and rotating diodes of the brushless excitation system is estimated. Finally, the complete system is simulated, comparing the main generator's voltage with both detailed and simplified excitation systems in several scenarios. These results show the accuracy of the simplified model against the detailed simulation model, resulting on an important hardware resources savings.
Rotor position sensor switches currents in brushless dc motors
1965-01-01
Reluctance switch incorporated in an induction motor is used for sensing rotor position and switching armature circuits in a brushless dc motor. This device drives the solar array system of an unmanned space satellite.
Tachometer Derived From Brushless Shaft-Angle Resolver
Howard, David E.; Smith, Dennis A.
1995-01-01
Tachometer circuit operates in conjunction with brushless shaft-angle resolver. By performing sequence of straightforward mathematical operations on resolver signals and utilizing simple trigonometric identity, generates voltage proportional to rate of rotation of shaft. One advantage is use of brushless shaft-angle resolver as main source of rate signal: no brushes to wear out, no brush noise, and brushless resolvers have proven robustness. No switching of signals to generate noise. Another advantage, shaft-angle resolver used as shaft-angle sensor, tachometer input obtained without adding another sensor. Present circuit reduces overall size, weight, and cost of tachometer.
Mathematical modeling of electromechanical processes in a brushless DC motor
Directory of Open Access Journals (Sweden)
V.I. Tkachuk
2014-03-01
Full Text Available On the basis of initial assumptions, a mathematical model that describes electromechanical processes in a brushless DC electric motor with a salient-pole stator and permanent-magnet excitation is created.
Mathematical modeling of electromechanical processes in a brushless DC motor
V.I. Tkachuk; V.I. Zhuk
2014-01-01
On the basis of initial assumptions, a mathematical model that describes electromechanical processes in a brushless DC electric motor with a salient-pole stator and permanent-magnet excitation is created.
Magnetic equivalent circuit model for unipolar hybrid excitation synchronous machine
Kupiec Emil; Przyborowski Włodzimierz
2015-01-01
Lately, there has been increased interest in hybrid excitation electrical machines. Hybrid excitation is a construction that combines permanent magnet excitation with wound field excitation. Within the general classification, these machines can be classified as modified synchronous machines or inductor machines. These machines may be applied as motors and generators. The complexity of electromagnetic phenomena which occur as a result of coupling of magnetic fluxes of separate excitation syste...
Development and Implementation of Biological Circuits Using Excitable and Non-Excitable Cells
Energy Technology Data Exchange (ETDEWEB)
Casasnovas-Orus, V.; Gomez-Cid, L.; Hernandez-Romero, I.; Fuentes, L.; Guillem, M.S.; Atienza, F.; Fernandez-Aviles, F.; Climent, A.M.
2016-07-01
Compared to conventional computation systems, living beings require reduced power and raw materials consumption, inviting to explore the concept of biological circuits. In this project, a proof-of-concept of logical biocircuits using cell patterns has been developed. These were based upon differential ionic communication between cells, being the cells types used excitable and non-excitable, modeled by cardiomyocytes and fibroblasts correspondingly. To begin, patterns for the basic logic computation blocks were designed, including the OR gate, AND gate and logic memory. The designs were evaluated with mathematical models and in vitro experiments. Results of mathematical modeling indicated that theoretical approval of the biocircuit function. Regarding in vitro biocircuit implementation, three different selective cell localization techniques proved useful for the pattern creation. Evaluation with optical mapping confirmed the operation of the OR gate and logic memory. More resolution in the cell placement strategy will be needed to observe the proper AND gate operation. Thus, fine-tuning of the implementation process will enable the construction of more complex biocircuits that will take on clinical applications relating to electric stimulation of tissues and programmed drug delivery. (Author)
Control motor brushless sensorless
Solchaga Pérez de Lazárraga, Gonzalo
2015-01-01
El proyecto consiste en la creación de un circuito capaz de controlar la velocidad de un motor brushless sensorless. Este tipo de motores eléctricos tienen como característica que no tienen escobillas para cambiar la polaridad del bobinado de su interior y tampoco precisan de un sensor que indique que ha realizado una vuelta. Los motores brushless que son controlados por este tipo de circuitos son específicos para aeronaves no tripuladas y requieren un diseño diferente a un motor brushless pe...
Priming Neural Circuits to Modulate Spinal Reflex Excitability
Estes, Stephen P.; Iddings, Jennifer A.; Field-Fote, Edelle C.
2017-01-01
While priming is most often thought of as a strategy for modulating neural excitability to facilitate voluntary motor control, priming stimulation can also be utilized to target spinal reflex excitability. In this application, priming can be used to modulate the involuntary motor output that often follows central nervous system injury. Individuals with spinal cord injury (SCI) often experience spasticity, for which antispasmodic medications are the most common treatment. Physical therapeutic/...
Characteristics of a half-wave rectified brushless synchronous generator
Hirakawa, Yuki; Higuchi, Tsuyoshi; Yokoi, Yuichi; Abe, Takashi
2014-01-01
The paper proposes the half-wave rectified brushless synchronous generator and analyzes the basic characteristics using the finite element method. It is based on the half-wave rectified excitation theory and doesn't need brush and slip ring system or permanent magnets for field excitation.
A Brushless Three-phase Synchronous Induction Motor with Two Stators
Inoue, Kenji; Yamashita, Hideo; Ohnogi, Yukio; Cingoski, Vlatko
1993-01-01
In this paper, a brushless three-phase synchronous induction motor with two stators which can self-start as a wound-rotor induction motor without external secondary resistance is proposed. In the proposed motor, two excitation schemes, separately and self-ones, can be realized. In the separately excitation scheme, the proposed machine can operate as a synchronous generator-motor. The proposed machine compared with traditional brushless synchronous motor with AC exciter has the following advan...
Priming Neural Circuits to Modulate Spinal Reflex Excitability
Estes, Stephen P.; Iddings, Jennifer A.; Field-Fote, Edelle C.
2017-01-01
While priming is most often thought of as a strategy for modulating neural excitability to facilitate voluntary motor control, priming stimulation can also be utilized to target spinal reflex excitability. In this application, priming can be used to modulate the involuntary motor output that often follows central nervous system injury. Individuals with spinal cord injury (SCI) often experience spasticity, for which antispasmodic medications are the most common treatment. Physical therapeutic/electroceutic interventions offer an alternative treatment for spasticity, without the deleterious side effects that can accompany pharmacological interventions. While studies of physical therapeutic/electroceutic interventions have been published, a systematic comparison of these approaches has not been performed. The purpose of this study was to compare four non-pharmacological interventions to a sham-control intervention to assess their efficacy for spasticity reduction. Participants were individuals (n = 10) with chronic SCI (≥1 year) who exhibited stretch-induced quadriceps spasticity. Spasticity was quantified using the pendulum test before and at two time points after (immediate, 45 min delayed) each of four different physical therapeutic/electroceutic interventions, plus a sham-control intervention. Interventions included stretching, cyclic passive movement (CPM), transcutaneous spinal cord stimulation (tcSCS), and transcranial direct current stimulation (tDCS). The sham-control intervention consisted of a brief ramp-up and ramp-down of knee and ankle stimulation while reclined with legs extended. The order of interventions was randomized, and each was tested on a separate day with at least 48 h between sessions. Compared to the sham-control intervention, stretching, CPM, and tcSCS were associated with a significantly greater reduction in spasticity immediately after treatment. While the immediate effect was largest for stretching, the reduction persisted
Self-Excited Single-Stage Power Factor Correction Driving Circuit for LED Lighting
Directory of Open Access Journals (Sweden)
Yong-Nong Chang
2014-01-01
Full Text Available This pa\tper proposes a self-excited single-stage high power factor LED lighting driving circuit. Being featured with power factor correction capability without needing any control devices, the proposed circuit structure is with low cost and suitable for commercial production. The power factor correction function is accomplished by using inductor in combination with a half-bridge quasi resonant converter to achieve active switching and yield out voltage regulation according to load requirement. Furthermore, the zero-voltage switching in the half-bridge converter can be attained to promote the overall performance efficiency of the proposed circuit. Finally, the validity and production availability of the proposed circuit will be verified as well.
Measuring Speed Of Rotation With Two Brushless Resolvers
Howard, David E.
1995-01-01
Speed of rotation of shaft measured by use of two brushless shaft-angle resolvers aligned so electrically and mechanically in phase with each other. Resolvers and associated circuits generate voltage proportional to speed of rotation (omega) in both magnitude and sign. Measurement principle exploits simple trigonometric identity.
Laser cooling and optical detection of excitations in a LC electrical circuit
DEFF Research Database (Denmark)
Taylor, J. M.; Sørensen, Anders Søndberg; Marcus, Charles Masamed
2011-01-01
We explore a method for laser cooling and optical detection of excitations in a room temperature LC electrical circuit. Our approach uses a nanomechanical oscillator as a transducer between optical and electronic excitations. An experimentally feasible system with the oscillator capacitively...... coupled to the LC and at the same time interacting with light via an optomechanical force is shown to provide strong electromechanical coupling. Conditions for improved sensitivity and quantum limited readout of electrical signals with such an “optical loud speaker” are outlined....
Controller for computer control of brushless dc motors. [automobile engines
Hieda, L. S. (Inventor)
1981-01-01
A motor speed and torque controller for brushless d.c. motors provides an unusually smooth torque control arrangement. The controller provides a means for controlling a current waveform in each winding of a brushless dc motor by synchronization of an excitation pulse train from a programmable oscillator. Sensing of torque for synchronization is provided by a light beam chopper mounted on the motor rotor shaft. Speed and duty cycle are independently controlled by controlling the frequency and pulse width output of the programmable oscillator. A means is also provided so that current transitions from one motor winding to another is effected without abrupt changes in output torque.
Directory of Open Access Journals (Sweden)
V. S. Malyar
2017-08-01
Full Text Available Purpose. Development of a mathematical model that enables to detect resonance modes during asynchronous startup of salient-pole synchronous motors, in which capacitors are switched on to increase the electromagnetic moment in the circuit of the excitation winding. Methodology. The asynchronous mode is described by a system of differential equations of the electric equilibrium of motor circuits written in orthogonal coordinate axes. The basis of the developed algorithm is the mathematical model of the high-level adequacy motor and the projection method for solving the boundary value problem for the equations of the electric equilibrium of the circuits written in orthogonal coordinate axes, taking into account the presence of capacitors in the excitation winding. The coefficients of differential equations are the differential inductances of the motor circuits, which are determined on the basis of the calculation of its magnetic circuit. As a result of the asymmetry of the rotor windings in the asynchronous mode, the current coupling and currents change according to the periodic law. The problem of its definition is solved as a boundary one. Results. A mathematical model for studying the asynchronous characteristics of synchronous motors with capacitors in an excitation winding is developed, by means of which it is possible to investigate the influence of the size of the capacity on the motor's starting properties and the resonance processes which may arise in this case. Scientific novelty. The developed method of mathematical modeling is based on a fundamentally new mathematical basis for the calculation of stationary dynamic modes of nonlinear electromagnetic circuits, which enables to obtain periodic coordinate dependencies, without resorting to the calculation of the transients. The basis of the developed algorithm is based on the approximation of state variables by cubic splines, the projection method of decomposition for the boundary value
Malik, Naveed ur Rehman
2015-01-01
This thesis deals with the modeling, analysis and control of a novel brushlessgenerator for wind power application. The generator is named as rotatingpower electronic brushless doubly-fed induction machine/generator (RPEBDFIM/G). A great advantage of the RPE-BDFIG is that the slip power recoveryis realized in a brushless manner. This is achieved by introducing an additionalmachine termed as exciter together with the rotating power electronicconverters, which are mounted on the shaft of a DFIG...
Directory of Open Access Journals (Sweden)
А.М. Galynovskiy
2015-11-01
Full Text Available The comparative analysis of direct frequency converters with artificial and natural- switching term of the cyclical control algorithm is presented; the recommendations for their using in brushless asynchronized machines with three-phase winding are developed. Converters with a limited number of full-controlled valves have large losses in safety circuits of gates, they can be used in system of automatic excitation control. The best quality of voltage and current load are provided by converters with natural commutation using modulated input voltage, the combined potential compounds windings supply and the combined method of thyristor controlling. When the load is divided into two three-phase groups, an even number of phases of the power supply for single phase of the load are applied the bridge converter circuit. Regulation of the load current is carried out by the excitation current of field exciters and by the control angle of thyristor. Converters can be used in high-power asynchronized motors and generators. In asynchronized compensators it is possible to use diode-thyristor converters without transmitting the control signals to the rotating part. The frequency converters without modulation of input voltage have the smallest increase in rated capacity of power supply. However, they have a low quality form of the output voltage at high power factor of load.
Controller for a High-Power, Brushless dc Motor
Fleming, David J.; Makdad, Terence A.
1987-01-01
Driving and braking torques controllable. Control circuit operates 7-kW, 45-lb-ft (61-N-m), three-phase, brushless dc motor in both motor and generator modes. In motor modes, energy from power source is pulse-width modulated to motor through modified "H-bridge" circuit, in generator mode, energy from motor is pulse-width modulated into bank of load resistors to provide variable braking torques. Circuit provides high-resolution torque control in both directions over wide range of speeds and torques. Tested successfully at bus voltages up to 200 Vdc and currents up to 45 A.
Magnetic Signature of Brushless Electric Motors
National Research Council Canada - National Science Library
Clarke, David
2006-01-01
Brushless electric motors are used in a number of underwater vehicles. When these underwater vehicles are used for mine clearance operations the magnetic signature of the brushless motors is important...
Fan, Denggui; Duan, Lixia; Wang, Qian; Luan, Guoming
2017-01-01
The mechanisms underlying electrophysiologically observed two-way transitions between absence and tonic-clonic epileptic seizures in cerebral cortex remain unknown. The interplay within thalamocortical network is believed to give rise to these epileptic multiple modes of activity and transitions between them. In particular, it is thought that in some areas of cortex there exists feedforward inhibition from specific relay nucleus of thalamus (TC) to inhibitory neuronal population (IN) which has even more stronger functions on cortical activities than the known feedforward excitation from TC to excitatory neuronal population (EX). Inspired by this, we proposed a modified computational model by introducing feedforward inhibitory connectivity within thalamocortical circuit, to systematically investigate the combined effects of feedforward inhibition and excitation on transitions of epileptic seizures. We first found that the feedforward excitation can induce the transition from tonic oscillation to spike and wave discharges (SWD) in cortex, i.e., the epileptic tonic-absence seizures, with the fixed weak feedforward inhibition. Thereinto, the phase of absence seizures corresponding to strong feedforward excitation can be further transformed into the clonic oscillations with the increasing of feedforward inhibition, representing the epileptic absence-clonic seizures. We also observed the other fascinating dynamical states, such as periodic 2/3/4-spike and wave discharges, reversed SWD and clonic oscillations, as well as saturated firings. More importantly, we can identify the stable parameter regions representing the tonic-clonic oscillations and SWD discharges of epileptic seizures on the 2-D plane composed of feedforward inhibition and excitation, where the physiologically plausible transition pathways between tonic-clonic and absence seizures can be figured out. These results indicate the functional role of feedforward pathways in controlling epileptic seizures and
Directory of Open Access Journals (Sweden)
Denggui Fan
2017-07-01
Full Text Available The mechanisms underlying electrophysiologically observed two-way transitions between absence and tonic-clonic epileptic seizures in cerebral cortex remain unknown. The interplay within thalamocortical network is believed to give rise to these epileptic multiple modes of activity and transitions between them. In particular, it is thought that in some areas of cortex there exists feedforward inhibition from specific relay nucleus of thalamus (TC to inhibitory neuronal population (IN which has even more stronger functions on cortical activities than the known feedforward excitation from TC to excitatory neuronal population (EX. Inspired by this, we proposed a modified computational model by introducing feedforward inhibitory connectivity within thalamocortical circuit, to systematically investigate the combined effects of feedforward inhibition and excitation on transitions of epileptic seizures. We first found that the feedforward excitation can induce the transition from tonic oscillation to spike and wave discharges (SWD in cortex, i.e., the epileptic tonic-absence seizures, with the fixed weak feedforward inhibition. Thereinto, the phase of absence seizures corresponding to strong feedforward excitation can be further transformed into the clonic oscillations with the increasing of feedforward inhibition, representing the epileptic absence-clonic seizures. We also observed the other fascinating dynamical states, such as periodic 2/3/4-spike and wave discharges, reversed SWD and clonic oscillations, as well as saturated firings. More importantly, we can identify the stable parameter regions representing the tonic-clonic oscillations and SWD discharges of epileptic seizures on the 2-D plane composed of feedforward inhibition and excitation, where the physiologically plausible transition pathways between tonic-clonic and absence seizures can be figured out. These results indicate the functional role of feedforward pathways in controlling epileptic
One hospital's clinical evaluation of brushless scrubbing.
Berman, Mara
2004-02-01
BRUSHLESS SCRUBBING rapidly is becoming an accepted method for surgical hand scrubbing. AN EVALUATION was undertaken at an acute care hospital in the southeastern United States to examine brushless scrubbing before laminectomy, craniotomy, and colectomy procedures. PATIENTS DID NOT SHOW an increase in postoperative surgical site infections when the brushless scrubbing product was used. SATISFACTION AND COMPLIANCE among users of the product was positive.
Hidden hyperchaos and electronic circuit application in a 5D self-exciting homopolar disc dynamo.
Wei, Zhouchao; Moroz, Irene; Sprott, J C; Akgul, Akif; Zhang, Wei
2017-03-01
We report on the finding of hidden hyperchaos in a 5D extension to a known 3D self-exciting homopolar disc dynamo. The hidden hyperchaos is identified through three positive Lyapunov exponents under the condition that the proposed model has just two stable equilibrium states in certain regions of parameter space. The new 5D hyperchaotic self-exciting homopolar disc dynamo has multiple attractors including point attractors, limit cycles, quasi-periodic dynamics, hidden chaos or hyperchaos, as well as coexisting attractors. We use numerical integrations to create the phase plane trajectories, produce bifurcation diagram, and compute Lyapunov exponents to verify the hidden attractors. Because no unstable equilibria exist in two parameter regions, the system has a multistability and six kinds of complex dynamic behaviors. To the best of our knowledge, this feature has not been previously reported in any other high-dimensional system. Moreover, the 5D hyperchaotic system has been simulated using a specially designed electronic circuit and viewed on an oscilloscope, thereby confirming the results of the numerical integrations. Both Matlab and the oscilloscope outputs produce similar phase portraits. Such implementations in real time represent a new type of hidden attractor with important consequences for engineering applications.
Brushless direct-current motors
Bahm, E. J.
1970-01-01
Survey results are presented on the use of unconventional motor windings and switching sequences to optimize performance of brushless dc motors. A motor was built, each coil terminal having a separate, accessible lead. With the shaft and all electronics excluded, length and outside diameter measured 1.25 and 0.75 in., respectively.
Wahlstrom-Helgren, Sarah; Klyachko, Vitaly A
2016-12-01
Feed-forward inhibitory (FFI) circuits are important for many information-processing functions. FFI circuit operations critically depend on the balance and timing between the excitatory and inhibitory components, which undergo rapid dynamic changes during neural activity due to short-term plasticity (STP) of both components. How dynamic changes in excitation/inhibition (E/I) balance during spike trains influence FFI circuit operations remains poorly understood. In the current study we examined the role of STP in the FFI circuit functions in the mouse hippocampus. Using a coincidence detection paradigm with simultaneous activation of two Schaffer collateral inputs, we found that the spiking probability in the target CA1 neuron was increased while spike precision concomitantly decreased during high-frequency bursts compared with a single spike. Blocking inhibitory synaptic transmission revealed that dynamics of inhibition predominately modulates the spike precision but not the changes in spiking probability, whereas the latter is modulated by the dynamics of excitation. Further analyses combining whole cell recordings and simulations of the FFI circuit suggested that dynamics of the inhibitory circuit component may influence spiking behavior during bursts by broadening the width of excitatory postsynaptic responses and that the strength of this modulation depends on the basal E/I ratio. We verified these predictions using a mouse model of fragile X syndrome, which has an elevated E/I ratio, and found a strongly reduced modulation of postsynaptic response width during bursts. Our results suggest that changes in the dynamics of excitatory and inhibitory circuit components due to STP play important yet distinct roles in modulating the properties of FFI circuits. Copyright © 2016 the American Physiological Society.
Brushless tachometer gives speed and direction
Nola, F. J.
1977-01-01
Brushless electronic tachometer measures rotational speed and rotational direction, maintaining accuracy at high or low speeds. Unit is particularly useful in vacuum environments requiring low friction.
Teaching about operation of brushless DC motors
Čufar, Aleksandra
2013-01-01
Brush DC motor is being replaced by brushless DC motors on every area of application. My diploma thesis is a presentation of brushless DC motor, how it works and its application. Within first part we describe various electric motors and their application. There are several types of electric motors division. Last to be added is a brushless motor. Within second part of thesis we look into a brushless DC motor, how it works, its application and control. In the third part of thesis we construct a...
A New Rb Lamp Exciter Circuit for Rb atomic clocks and Studies on Transition from Ring to Red mode
Singh, Savita; Saxena, G M
2010-01-01
In this paper we describe the development of novel RF exciter circuit for electrode less Rb lamp. The lamp exciter circuit is a RF oscillator with a a new configuration operating at 60 to 65 MHz frequency with 3 to 4 watt power. The Rb lamp is used in exciting the ground state hyperfine transitions in Rb atom in a glass cell placed inside a tuned microwave cavity, As the frequency of these hyperfine transitions is very stable it is used in the development of Rb atomic clock by phase locking the oven controlled crystal oscillator (OCXO) to this atomic transition frequency. The details of the Rb lamp exciter are presented in the paper.The Lamp is ideally operated in ring mode as in this mode the linewidth is narrow and there is no self reversal. However, high temperature and RF excitation power may drive the Rb lamp to red mode which gives rise to line broadening and self reversal. It is the experience that mode change from ring to red deteriorates the atomic signal strength and S/N. In this paper the reasons o...
Hao, Kuan-Sheng; Huang, Song-Ling; Zhao, Wei; Wang, Shen
2011-06-01
This paper presents an analytical method for electromagnetic acoustic transducers (EMATs) under voltage excitation and considers the non-uniform distribution of the biased magnetic field. A complete model of EMATs including the non-uniform biased magnetic field, a pulsed eddy current field and the acoustic field is built up. The pulsed voltage excitation is transformed to the frequency domain by fast Fourier transformation (FFT). In terms of the time harmonic field equations of the EMAT system, the impedances of the coils under different frequencies are calculated according to the circuit-field coupling method and Poynting's theorem. Then the currents under different frequencies are calculated according to Ohm's law and the pulsed current excitation is obtained by inverse fast Fourier transformation (IFFT). Lastly, the sequentially coupled finite element method (FEM) is used to calculate the Lorentz force in the EMATs under the current excitation. An actual EMAT with a two-layer two-bundle printed circuit board (PCB) coil, a rectangular permanent magnet and an aluminium specimen is analysed. The coil impedances and the pulsed current are calculated and compared with the experimental results. Their agreement verified the validity of the proposed method. Furthermore, the influences of lift-off distances and the non-uniform static magnetic field on the Lorentz force under pulsed voltage excitation are studied.
Motor control for a brushless DC motor
Peterson, William J. (Inventor); Faulkner, Dennis T. (Inventor)
1985-01-01
This invention relates to a motor control system for a brushless DC motor having an inverter responsively coupled to the motor control system and in power transmitting relationship to the motor. The motor control system includes a motor rotor speed detecting unit that provides a pulsed waveform signal proportional to rotor speed. This pulsed waveform signal is delivered to the inverter to thereby cause an inverter fundamental current waveform output to the motor to be switched at a rate proportional to said rotor speed. In addition, the fundamental current waveform is also pulse width modulated at a rate proportional to the rotor speed. A fundamental current waveform phase advance circuit is controllingly coupled to the inverter. The phase advance circuit is coupled to receive the pulsed waveform signal from the motor rotor speed detecting unit and phase advance the pulsed waveform signal as a predetermined function of motor speed to thereby cause the fundamental current waveform to be advanced and thereby compensate for fundamental current waveform lag due to motor winding reactance which allows the motor to operate at higher speeds than the motor is rated while providing optimal torque and therefore increased efficiency.
Torque-Summing Brushless Motor
Vaidya, J. G.
1986-01-01
Torque channels function cooperatively but electrically independent for reliability. Brushless, electronically-commutated dc motor sums electromagnetic torques on four channels and applies them to single shaft. Motor operates with any combination of channels and continues if one or more of channels fail electrically. Motor employs single stator and rotor and mechanically simple; however, each of channels electrically isolated from other so that failure of one does not adversely affect others.
Control aspects of the brushless doubly-fed machine
Lauw, H. K.; Krishnan, S.
1990-09-01
This report covers the investigations into the control aspects of a variable-speed generation (VSG) system using a brushless double-fed generator excited by a series-resonant converter. The brushless double-fed machine comprises two sets of stator 3-phase systems which are designed with common windings. The rotor is a cage rotor resembling the low-cost and robust squirrel cage of a conventional induction machine. The system was actually designed and set up in the Energy Laboratory of the Department of Electrical and Computer Engineering at Oregon State University. The series-resonant converter designed to achieve effective control for variable-speed generation with the brushless doubly-fed generator was adequate in terms of required time response and regulation as well as in providing for adequate power quality. The three elements of the VSG controller, i.e., voltage or reactive power controller, the efficiency maximizer and the stabilizer, could be designed using conventional microprocessor elements with a processing time well within the time period required for sampling the variables involved with executing the control tasks. The report treats in detail the stability problem encountered in running the machine at certain speed regions, even if requirements for steady-state stability are satisfied. In this unstable region, shut down of the VSG system is necessary unless proper stabilization controls are provided for. The associated measures to be taken are presented.
Design Considerations for the Brushless Doubly-Fed (Induction) Machine
McMahon, R A; Mathekga, M. E.; Wang, X.; Tatlow, M. R.
2015-01-01
This is the author accepted manuscript. The final version is available from The Institution of Engineering and Technology via https://doi.org/10.1049/iet-epa.2015.0405 A design procedure for the Brushless Doubly Fed machine is based on equations derived from a simplified equivalent circuit. The method allows the many variables in the design of this machine to be handled in straightforward way. Relationships are given for the division of slot area between the two stator windings and for the...
Malik, Naveed ur Rehman
2012-01-01
This thesis deals with the steady-state, dynamic and control aspects of new type of brushless configuration of a doubly-fed induction machine in which the slip rings and carbon brushes are replaced by rotating power electronics and a rotating exciter. The aim is to study the stability of this novel configuration of the generator under mechanical and grid disturbances for wind power applications. The derivation, development and analysis of the steady-state model of the brushless doubly-fed ind...
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Uma Devi Kumaravelu
2012-01-01
Full Text Available A method of simulation and modeling outer rotor permanent magnet brushless DC (ORPMBLDC motor under dynamic conditions using finite element method by FEMM 4.2 software package is presented. In the proposed simulation, the torque developed at various positions of the rotor, under a complete cycle of excitation of the stator, is analysed. A novel method of sinusoidal excitation is proposed to enhance the overall torque development of ORPMBLDC motor.
Uma Devi Kumaravelu; Sanavullah Mohamed Yakub
2012-01-01
A method of simulation and modeling outer rotor permanent magnet brushless DC (ORPMBLDC) motor under dynamic conditions using finite element method by FEMM 4.2 software package is presented. In the proposed simulation, the torque developed at various positions of the rotor, under a complete cycle of excitation of the stator, is analysed. A novel method of sinusoidal excitation is proposed to enhance the overall torque development of ORPMBLDC motor.
National Research Council Canada - National Science Library
Kato Engineering Inc
1984-01-01
Contents: Common frame brushless synchronous motor-generator set - Field failure and out-of-step protection assembly for sychronous motor - Kato KCR 360 voltage regulators - Installation and maintenance...
Jian-ping Wen; Chuan-wei Zhang
2015-01-01
In order to improve energy utilization rate of battery-powered electric vehicle (EV) using brushless DC machine (BLDCM), the model of braking current generated by regenerative braking and control method are discussed. On the basis of the equivalent circuit of BLDCM during the generative braking period, the mathematic model of braking current is established. By using an extended state observer (ESO) to observe actual braking current and the unknown disturbances of regenerative braking system, ...
Controlling a Four-Quadrant Brushless Three-Phase dc Motor
Nola, F. J.
1986-01-01
Control circuit commutates windings of brushless, three-phase, permanent-magnet motor operating from power supply. With single analog command voltage, controller makes motor accelerate, drive steadily, or brake regeneratively, in clockwise or counterclockwise direction. Controller well suited for use with energy-storage flywheels, actuators for aircraft-control surfaces, cranes, industrial robots, and other electromechanical systems requiring bidirectional control or sudden stopping and reversal.
Chen, T; Beu, S C; Kaiser, N K; Hendrickson, C L
2014-06-01
A conventional Fourier transform-Ion Cyclotron Resonance (ICR) detection cell is azimuthally divided into four equal sections. One pair of opposed electrodes is used for ion cyclotron excitation, and the other pair for ion image charge detection. In this work, we demonstrate that an appropriate electrical circuit facilitates excitation and detection on one pair of opposed electrodes. The new scheme can be used to minimize the number of electrically independent ICR cell electrodes and/or improve the electrode geometry for simultaneously increased ICR signal magnitude and optimal post-excitation radius, which results in higher signal-to-noise ratio and decreased space-charge effects.
Zao, Yongming; Ouyang, Qi; Chen, Jiawei; Zhang, Xinglan; Hou, Shuaicheng
2017-08-01
This paper investigates the design and implementation of an improved series-parallel inductor-capacitor-inductor (LsCpLp) resonant circuit power supply for excitation of electromagnetic acoustic transducers (EMATs). The main advantage of the proposed resonant circuit is the absence of a high-permeability dynamic transformer. A high-frequency pulsating voltage gain can be achieved through a double resonance phenomenon. Both resonant tailing behavior and higher harmonics are suppressed by the improved resonant circuit, which also contributes to the generation of ultrasonic waves. Additionally, the proposed circuit can realize impedance matching and can also optimize the transduction efficiency. The complete design and implementation procedure for the power supply is described and has been validated by implementation of the proposed power supply to drive a portable EMAT. The circuit simulation results show close agreement with the experimental results and thus confirm the validity of the proposed topology. The proposed circuit is suitable for use as a portable EMAT excitation power supply that is fed by a low-voltage source.
Modeling of brushless dc generating systems using diakoptics
Vadher, Vinod; Gregory, Keith; Kettleborough, J. G.; Smith, Ivor R.
1993-01-01
The mathematical modeling of a brushless dc generator is described, as an illustration of the application of diakoptic techniques to the analysis of small-scale electrical power supply systems. Modeling of the generator and its output rectifier is accomplished using an established matrix technique that accounts for the continuously changing conduction pattern of the diode bridge network. The advantages of using diakoptics are introduced when consideration is given to the main generator linked to its exciter and to the automatic voltage regulator and permanent magnet generator which are often included in a complete unit. A solution algorithm is presented for this overall arrangement and a comparison is made between theoretical and practical results for a typical 3-stage 4000 rev/min 10.3 kW 28 V unit.
Design and evaluation of brushless electrical generators
Collins, F. A.; Ellis, J. N.
1970-01-01
Ten design manuals assembled and nine computer programs are developed for evaluation of proposed designs of brushless rotating electrical generators. Design manual package provides all information required for generator design, and computer programs permit calculation of performance of specific designs including effects of materials.
Variable Rail Voltage Control of a Brushless DC (BLDC) Motor
2013-01-01
Variable Rail Voltage Control of a Brushless DC (BLDC) Motor by Yuan Chen, Joseph Conroy, and William Nothwang ARL-TR-6308 January 2013...TR-6308 January 2013 Variable Rail Voltage Control of a Brushless DC (BLDC) Motor Yuan Chen, Joseph Conroy, and William Nothwang Sensors...DATES COVERED (From - To) 4. TITLE AND SUBTITLE Variable Rail Voltage Control of a Brushless DC (BLDC) Motor 5a. CONTRACT NUMBER 5b. GRANT
Generalized model of brushless dc generator
Vadher, V. V.; Kettleborough, J. Gordon; Smith, I. R.; Gerges, Wahid R.
1989-07-01
A generalized model is described for a brushless dc machine consisting of a multiphase synchronous machine with a full-wave bridge rectifier connected to its output terminals. The state-variable equations for the machine are suitable for numerical integration on a digital computer, and are assembled in a form which permits investigations to be made on the effects of different numbers of armature phase windings and different winding connections. The model has been used in both steady-state and transient studies on a number of generating units, with the detailed information which is provided being beneficial to design engineers. Comparisons presented between predicted and measured results illustrate the validity of the model and the mathematical techniques adopted, and confirm that accurate information on the performance of a brushless generator may be obtained prior to manufacture.
Axial flux permanent magnet brushless machines
Gieras, Jacek F; Kamper, Maarten J
2008-01-01
Axial Flux Permanent Magnet (AFPM) brushless machines are modern electrical machines with a lot of advantages over their conventional counterparts. They are being increasingly used in consumer electronics, public life, instrumentation and automation system, clinical engineering, industrial electromechanical drives, automobile manufacturing industry, electric and hybrid electric vehicles, marine vessels and toys. They are also used in more electric aircrafts and many other applications on larger scale. New applications have also emerged in distributed generation systems (wind turbine generators
Kitamura, Norihiko; Masuda, Arata
2017-04-01
This paper presents a resonance-type vibration energy harvester using a nonlinear oscillator with self-excitation circuit. The bandwidth of the resonance peak and the performance of the power generation at the resonance frequency are trade- offs for the conventional linear vibration energy harvester. A nonlinear oscillator can expand the resonance frequency band to generate larger electric power in a wider frequency range. However, it is difficult for the harmonically excited nonlinear vibration energy harvester to maintain the highest-energy response under the presence of disturbances since the nonlinear oscillator can have multiple stable steady-state solutions in the resonance band. In order to provide the global stability to the highest-energy solution, we introduce a self-excitation circuit which can destabilize other unexpected lower-energy solutions and entrain the oscillator only in the highest-energy solution. Numerical and experimental studies show that the proposed self-excitation control can provide the global stability to the highest-solution and maintain the high performance of the power generation in the widened resonance frequency band.
Directory of Open Access Journals (Sweden)
Jian-ping Wen
2015-01-01
Full Text Available In order to improve energy utilization rate of battery-powered electric vehicle (EV using brushless DC machine (BLDCM, the model of braking current generated by regenerative braking and control method are discussed. On the basis of the equivalent circuit of BLDCM during the generative braking period, the mathematic model of braking current is established. By using an extended state observer (ESO to observe actual braking current and the unknown disturbances of regenerative braking system, the autodisturbances rejection controller (ADRC for controlling the braking current is developed. Experimental results show that the proposed method gives better recovery efficiency and is robust to disturbances.
Rotor apparatus for high strength undiffused brushless electric machine
Hsu, John S [Oak Ridge, TN
2006-01-24
A radial gap brushless electric machine (30) having a stator (31) and a rotor (32) and a main air gap (34) also has at least one stationary excitation coil (35a, 36a) separated from the rotor (32) by a secondary air gap (35e, 35f, 36e, 36f) so as to induce a secondary flux in the rotor (32) which controls a resultant flux in the main air gap (34). Permanent magnetic (PM) material (38) is disposed in spaces between the rotor pole portions (39) to inhibit the second flux from leaking from the pole portions (39) prior to reaching the main air gap (34). By selecting the direction of current in the stationary excitation coil (35a, 36a) both flux enhancement and flux weakening are provided for the main air gap (34). Improvements of a laminated rotor, an end pole structure, and an arrangement of the PM elements for providing an arrangement of the flux paths from the auxiliary field coil assemblies are also disclosed.
Magnetic Circuit & Torque Analysis Of Brushless DC Motor
Directory of Open Access Journals (Sweden)
Arif J. Abbas
2013-05-01
Full Text Available This work is concerned with magnetic and torque analysis of BLDCM and with development of a method of designing BLDCM that have symmetric winding on the rotor .make significant contribution to the rotor inductance position difficult. It is also show that the prediction detent torque can be extremely sensitive to the permanent magnet by altering magnet arc width. Finally, simple lumped models that allow one to predict motor performance and characteristics as a function of main dimension, magnet residual flux density and phase current are developed. These models are used as a basis for an approach to designing BLDCM
Method and machine for high strength undiffused brushless operation
Hsu, John S.
2003-06-03
A brushless electric machine (30) having a stator (31) and a rotor (32) and a main air gap (34), the rotor (32) having pairs of rotor pole portions (22b, 22c, 32f, 32l) disposed at least partly around the axis of rotation (32p) and facing the main air gap (24b, 24c, 34), at least one stationary winding (20b, 20c, 33b) separated from the rotor (22b, 22c, 32) by a secondary air gap (23b, 23c, 35) so as to induce a rotor-side flux in the rotor (22b, 22c, 32) which controls a resultant flux in the main air gap (24b, 24c, 34). PM material (27b, 27c) is disposed in spaces between the rotor pole portions (22b, 22c, 32f, 32l) to inhibit the rotor-side flux from leaking from said pole portions (22b, 22c, 32f, 32l) prior to reaching the main air gap (24b, 24c, 34). By selecting the direction of current in the stationary winding (20b, 20c, 33b) both flux enhancement and flux weakening are provided for the main air gap (24b, 24c, 34). The stationary windings (31a, 33b) which are used for both primary and secondary excitation allow for easier adaptation to cooling systems as described. A method of non-diffused flux enhancement and flux weakening is also disclosed.
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U. Marschner
2014-09-01
Full Text Available Two-layer flexure beams often serve as basic transducers in actuators and sensors. In this paper a generalized description of their stimuli-influenced mechanical behavior is derived. For small deflection angles this description includes a multi-port circuit or network representation with lumped elements for a beam part of finite length. A number of coupled finite beam parts model the dynamic behavior including the first natural frequencies of the beam. For piezoelectric and piezomagnetic interactions, reversible transducer models are developed. The piezomagnetic two-layer beam model is extended to include solenoid and planar coils. Linear network theory is applied in order to determine network parameters and to simplify the circuit representation. The resulting circuit model is the basis for a fast simulation of the dynamic system behavior with advanced circuit simulators and, thus, the optimization of the system. It is also a useful tool for understanding and explaining this multi-domain system through basic principles of general system theory.
Design and development of a brushless, direct drive solar array reorientation system
Jessee, R. D.
1972-01-01
This report covers the design and development of the laboratory model, and is essentially a compilation of reports covering the system and its various parts. To enhance completeness, the final report of Phase 1 covering circuit development of the controller is also included. A controller was developed for a brushless, direct-drive, single axis solar array reorientation system for earth-pointed, passively-stabilized spacecraft. A control systems was designed and breadboard circuits were built and tested for performance. The controller is designed to take over automatic control of the array on command after the spacecraft is stabilized in orbit. The controller will orient the solar array to the sun vector and automatically track to maintain proper orientation. So long as the orbit is circular, orientation toward the sun is maintained even though the spacecraft goes into the shadow of the earth. Particular attention was given in the design to limit reaction between the array and the spacecraft.
Brushless Slip-Power Recovery System Simulation by Using Modified Nodal Analysis
Kato, Shinji; Hoshi, Nobukazu; Oguchi, Kuniomi
A novel simulation model for multiphase induction machines formulated by the modified nodal analysis is proposed. In the proposed model, the voltage and the torque equations for an elementary induction machine are used to formulate a multiphase induction machine. It is not necessary to derive the state equations for the multiphase induction machine corresponding to the conduction modes of a power electronics circuit. Thus, it is easy to simulate the complex systems including the multiphase induction machines and many power devices. Two brushless slip-power recovery systems are discussed in this paper to verify the effectiveness of the proposed model. The simulation results show good agreements with the experimental results. The proposed model enables to simulate the systems consisting of the multiphase induction machines and many power devices without derivations of the state equations for multiphase induction machines corresponding to the conduction modes of a power electronics circuit.
Brushless dc motor uses electron beam switching tube as commutator
Studer, P.
1965-01-01
Electron beam switching tube eliminates physical contact between rotor and stator in brushless dc motor. The tube and associated circuitry control the output of a dc source to sequentially energize the motor stator windings.
Brushless direct-current motor with stationary armature and field
Studer, P. A.
1970-01-01
Electronically commutated dc motor has an active fixed field winding, and active fixed armature winding, and passive rotor. By use of brushless dc motor switching technique, motor provides continuous controllable and reversible torque without use of sliding contacts.
Universal Brushless-DC Motor Controller for Space Applications Project
National Aeronautics and Space Administration — The goal of this SBIR is to adapt an initial prototype ultra-miniature high-performance brushless-DC-motor controller, code named 'Puck', for use by NASA across a...
Jono, Yasutomo; Iwata, Yasuyuki; Mizusawa, Hiroki; Hiraoka, Koichi
2016-11-01
The present study examined whether the excitability of the corticospinal pathway and the GABA-mediated inhibitory circuits of the primary motor cortex that project onto the corticospinal neurons in the tonically contracting hand muscle are changed by tonic contraction of the adjacent hand muscle. The motor evoked potential (MEP) and cortical silent period (CSP) in the tonically contracting hand muscle were obtained while the adjacent hand muscle was either tonically contracting or at rest. The MEP and CSP of the first dorsal interosseous (FDI) muscle elicited across the scalp sites where the MEP is predominantly elicited in the FDI muscle were decreased by tonic contraction of the abductor digiti minimi (ADM) muscle. The centers of the area of the MEP and the duration of the CSP in the FDI muscle elicited across the sites where the MEP is predominantly elicited in the FDI muscle were lateral to those in the FDI muscle elicited across the sites where the MEP is elicited in both the FDI and ADM muscles. They were also lateral to those in the ADM muscle elicited either across the sites where the MEP is predominantly elicited in the ADM muscle, or across the sites where the MEP is elicited in both the FDI and ADM muscles. The decrease in the corticospinal excitability and the excitability of the GABA-mediated inhibitory circuits of the primary motor cortex that project onto the corticospinal neurons in the FDI muscle may be due either to (1) the interaction between the activity of the lateral area of the FDI representation and the descending drive to the ADM muscle, or (2) the decreased susceptibility of the primary motor area that predominantly projects onto the corticospinal neurons in the FDI muscle, which also plays a role in independent finger movement when both the FDI and ADM muscles act together as synergists.
Summary on Sensorless permanent magnet Brushless DC Motor Control Strategies
Directory of Open Access Journals (Sweden)
Li Hai Xia
2016-01-01
Full Text Available This paper aims at discussing the development process and application of permanent magnet brushless DC motor. By referring to the related literatures, this thesis gives an overview of several common non-position sensor detection technologies, analyzing their strengths and weaknesses as well as a number of new and improved methods in practical applications. Besides, The application situation of the electric door with sensorless permanent magnet brushless DC motor was illustrated.
System For Characterizing Three-Phase Brushless dc Motors
Howard, David E.; Smith, Dennis A.
1996-01-01
System of electronic hardware and software developed to automate measurements and calculations needed to characterize electromechanical performances of three-phase brushless dc motors, associated shaft-angle sensors needed for commutation, and associated brushless tachometers. System quickly takes measurements on all three phases of motor, tachometer, and shaft-angle sensor simultaneously and processes measurements into performance data. Also useful in development and testing of motors with not only three phases but also two, four, or more phases.
Comparative analysis of some brushless motors based on catalog data
Directory of Open Access Journals (Sweden)
Anton Kalapish
2005-10-01
Full Text Available Brushless motors (polyphased AC induction, synchronous and brushless DC motors have no alternatives in modern electric drives. They possess highly efficient and very wide range of speeds. The objective of this paper is to represent some relation between the basic parameters and magnitudes of electrical machines. This allows to be made a comparative analysis and a choice of motor concerning each particular case based not only on catalogue data or price for sale.
An enhanced Z-source inverter topology-based permanent magnet brushless DC motor drive speed control
Geno Peter, P.; Rajaram, M.
2015-08-01
In this paper, an enhanced Z-source inverter (ZSI) is introduced for controlling the speed of permanent magnet brushless DC motor (PMBLDCM) drive. It is the extension of the conventional ZSI and the elements used in the circuit are the same as those of the conventional ZSI, except that the position of Inverter Bridge and diode would be exchanged from the classical circuit diagram. This exchanged circuit avoids the startup path of the inrush current and hence reduces the inrush current and improves the motor efficiency. Different modes of enhanced ZSI are studied with PMBLDCM. The voltage polarity of Z-source capacitors in the proposed circuit is the same as that of the input voltage polarity. Furthermore, to get the same voltage boost, the capacitor voltage stress is reduced to a significant extent. The speed control capability of the proposed brushless DC motor drive is compared with that of the conventional ZSI. The proposed ZSI is implemented in MATLAB/Simulink working platform and the output performance is evaluated. Also, the performance of voltage ratio is analysed both by simulation and mathematical models. All these analyses are known to express the innovative features of the proposed system.
Method and radial gap machine for high strength undiffused brushless operation
Hsu, John S.
2006-10-31
A radial gap brushless electric machine (30) having a stator (31) and a rotor (32) and a main air gap (34) also has at least one stationary excitation coil (35a, 36a) separated from the rotor (32) by a secondary air gap (35e, 35f, 36e, 36f) so as to induce a secondary flux in the rotor (32) which controls a resultant flux in the main air gap (34). Permanent magnetic (PM) material (38) is disposed in spaces between the rotor pole portions (39) to inhibit the second flux from leaking from the pole portions (39) prior to reaching the main air gap (34). By selecting the direction of current in the stationary excitation coil (35a, 36a) both flux enhancement and flux weakening are provided for the main air gap (34). A method of non-diffused flux enhancement and flux weakening for a radial gap machine is also disclosed.
Directory of Open Access Journals (Sweden)
Yu Feng
2017-01-01
Full Text Available We introduce and investigate a four-dimensional hidden hyperchaotic system without equilibria, which is obtained by augmenting the three-dimensional self-exciting homopolar disc dynamo due to Moffatt with an additional control variable. Synchronization of two such coupled disc dynamo models is investigated by active control and sliding mode control methods. Numerical integrations show that sliding mode control provides a better synchronization in time but causes chattering. The solution is obtained by switching to active control when the synchronization errors become very small. In addition, the electronic circuit of the four-dimensional hyperchaotic system has been realized in ORCAD-PSpice and on the oscilloscope by amplitude values, verifying the results from the numerical experiments.
Design and Optimization of a Brushless Wound-Rotor Vernier Machine
Directory of Open Access Journals (Sweden)
Qasim Ali
2018-02-01
Full Text Available In this paper, a permanent magnet (PM-less, brushless, wound-rotor vernier machine (BL-WRVM is proposed for variable speed applications such as electric vehicles and washing machines. The wound rotor is excited through an already existing brushless topology, which requires a dual inverter configuration to generate an additional subharmonic component in the stator magnetomotive force (MMF. Different from permanent magnet vernier machines (PMVMs, the proposed BL-WRVM provides easy regulation of the rotor flux for variable speed operation. A 24-slot, 4-pole stator, and 44-pole outer rotor were designed, and 2D finite element analysis (FEA was carried out to determine the performance of the proposed machine. To improve the performance of the proposed machine, optimization of the rotor and stator winding turns was done. The optimized model was further analyzed for wide-speed operation, and its performance was then compared with that of an equivalent permanent magnet vernier machine (PMVM. The proposed machine has the advantage of low cost due to its PM-less structure and is suitable for variable speed applications.
High-temperature brushless DC motor controller
Energy Technology Data Exchange (ETDEWEB)
Cieslewski, Crzegorz; Lindblom, Scott C.; Maldonado, Frank J.; Eckert, Michael Nathan
2017-05-16
A motor control system for deployment in high temperature environments includes a controller; a first half-bridge circuit that includes a first high-side switching element and a first low-side switching element; a second half-bridge circuit that includes a second high-side switching element and a second low-side switching element; and a third half-bridge circuit that includes a third high-side switching element and a third; low-side switching element. The motor controller is arranged to apply a pulse width modulation (PWM) scheme to switch the first half-bridge circuit, second half-bridge circuit, and third half-bridge circuit to power a motor.
Zschorlich, Volker R.; Köhling, Rüdiger
2013-01-01
The present study shows evidence for conscious motor intention in motor preparation prior to movement execution. We demonstrate that conscious motor intention of directed movement, combined with minimally supra-threshold transcranial magnetic stimulation (TMS) of the motor cortex, determines the direction and the force of resulting movements, whilst a lack of intention results in weak and omni-directed muscle activation. We investigated changes of consciously intended goal directed movements by analyzing amplitudes of motor-evoked potentials of the forearm muscle, flexor carpi radialis (FCR), and extensor carpi radialis (ECR), induced by transcranial magnetic stimulation over the right motor cortex and their motor outcome. Right-handed subjects were asked to develop a strong intention to move their left wrist (flexion or extension), without any overt motor output at the wrist, prior to brain stimulation. Our analyses of hand acceleration and electromyography showed that during the strong motor intention of wrist flexion movement, it evoked motor potential responses that were significantly larger in the FCR muscle than in the ECR, whilst the opposite was true for an extension movement. The acceleration data on flexion/extension corresponded to this finding. Under no-intention conditions again, which served as a reference for motor evoked potentials, brain stimulation resulted in undirected and minimally simultaneous extension/flexion innervation and virtually no movement. These results indicate that conscious intentions govern motor function, which in turn shows that a neuronal activation representing an “intention network” in the human brain pre-exists, and that it functionally represents target specific motor circuits. Until today, it was unclear whether conscious motor intention exists prior to movement, or whether the brain constructs such an intention after movement initiation. Our study gives evidence that motor intentions become aware before any motor
A Design Study of Dual-Stator Permanent Magnet Brushless DC Motor
Directory of Open Access Journals (Sweden)
Yanliang Xu
2013-11-01
Full Text Available Dual-stator permanent magnet brushless DC Motor (DSBLDC features high efficiency and torque-density. As DSBLDC could operate in various states according to different winding connection modes, it is fully qualified for electric vehicle (EV drive. Unfortunately, due to the particular dual-stator structure, this kind of motor is difficult to be designed by available design methods. However, this paper demonstrates that a DSBLDC with series magnetic circuit structure can be regarded as being consisted of two independent BLDCs, i.e. an inner-rotor BLDC and an outer-rotor BLDC. Thus, the DSBLDC can be divided into two single-stator BLDCs. Based on this demonstration, the design method is verified by finite element analysis (FEA, and the basic design steps are given. Furthermore, experimental results of the prototype motor have verified the correction of the method, which also indicates that the motor with superior performance is adapted to EV drive.
FEM Analysis of Brushless DC Servomotor with Fractional Number of Slots per Pole
Directory of Open Access Journals (Sweden)
BALUTA, G.
2014-02-01
Full Text Available The authors present in this paper the analysis with Finite Element Method (FEM of the magnetic circuit for a Brushless DC servomotor with fractional number of slots/pole (9 slots and 10 poles. For this purpose, FEMM 4.2 software package was used for the analysis. To obtain the waveforms of Back-ElectroMotive Forces (BEMFs, electromagnetic and cogging torque for servomotor a program in LUA scripting language (integrated into interactive shell of FEMM4.2 has been created. A comparation with a structure with integer number of slots/pole (18 slots and 6 poles was also realized. The analysis results prove that the structure chosen is an optimal solution: sinusoidal waveforms of BEMFs, improved electromagnetic torque and reduced cogging torque. Therefore, the operating characteristics of the servomotor with 9/10 slots/poles manufactured by Sistem Euroteh Company and included in an integrated electrical drives system are presented in this paper.
Hybrid Adaptive Observer for a Brushless DC Motor
DEFF Research Database (Denmark)
Niemczyk, Piotr; Porchez, Thomas; Bendtsen, Jan Dimon
2008-01-01
A novel hybrid adaptive observer for Brushless DC Motors (BLDCM) is presented. It uses two current measurements of BLDCM phases to estimate the angle and the speed of the rotor. The observer is designed on the basis of a hybrid model, which is also presented in this paper. The parameters of the o...
Brushless dc motors. [applications in non-space technology
1975-01-01
Brushless dc motors were intensively developed and tested over several years before qualification as the prime movers for Apollo Spacecraft life support blowers, and for circulating oxygen in the lunar portable life support system. Knowledge gained through prototype development and critical testing has significantly influenced the technology employed, broadened markets and applications, and reduced the cost of present day motors.
A brushless dc spin motor for momentum exchange altitude control
Stern, D.; Rosenlieb, J. W.
1972-01-01
Brushless dc spin motor is designed to use Hall effect probes as means of revolving rotor position and controlling motor winding currents. This results in 3 to 1 reduction in watt-hours required for wheel acceleration, a 2 to 1 reduction in power to run wheel, and a 10 to 1 reduction in the electronics size and weight.
Power factor correction (PFC) converters feeding brushless DC ...
African Journals Online (AJOL)
This paper presents a comprehensive study of power factor correction (PFC) converters for feeding brushless DC (BLDC) motor drive. This work explores various configurations of PFC converters which are classified into five different categories of non-isolated, bridgeless (BL) non-isolated, isolated, BL-isolated PFC ...
Sensorless Control of PM Synchronous Motors and Brushless DC Motors
DEFF Research Database (Denmark)
Montesinos, D.; Galceran, Samuel; Blaabjerg, Frede
2005-01-01
This paper provides a review of the literature addressing sensorless operation methods of PM brushless machines. The methods explained are state-of-the-art of open and closed loop control strategies. The closed loop review includes those methods based on voltage and current measurements, those me...
Effect of excitation methods on electrical characteristics of fully superconducting generator model
Muta, Itsuya; Tsukiji, H.; Handa, N.; Hoshino, Tsutomu; Mukai, E.
1994-07-01
We have fabricated a fully superconducting generator of 20 kW class, in which both of armature and field coils are made of superconductors. Two different types of excitation system were selected and tested: a brushless excitation method consisted of 'magnetic flux pump' and a conventional excitation method equipped with collector ring and brushes. The paper describes the experimental machine model and the comparison of test results between the two different types of excitation methods.
Characterization of Small DC Brushed and Brushless Motors
2013-03-01
back EMF signals for a brushless motor. ............................13 Figure 11. Torque vs. RPM at various voltages, 100% throttle for an A05-3700...electrical power to mechanical power in the form of rotary motion. This electromechanical system is characterized by a few specific parameters that, if...of the magnets over the coils also creates a back electromotive force ( EMF ) on the unenergized stator, which is sensed by the speed controller to
Pulse-Width-Modulating Driver for Brushless dc Motor
Salomon, Phil M.
1991-01-01
High-current pulse-width-modulating driver for brushless dc motor features optical coupling of timing signals from low-current control circuitry to high-current motor-driving circuitry. Provides high electrical isolation of motor-power supply, helping to prevent fast, high-current motor-driving pulses from being coupled through power supplies into control circuitry, where they interfere with low-current control signals.
Modeling and Design of Brushless Doubly-Fed Induction Machines
Wang, X.
2017-01-01
The rapid increase of wind power in the power grid results in high grid connection requirements for wind turbines. Moreover, the reliability of wind turbines becomes more and more important, especially in offshore applications. One potential solution for these demands is the wind turbine drive-train based on the brushless doubly-fed induction machine (DFIM). This machine type has no brushes or slip-rings on the rotor side which provides an attractive alternative to the DFIM which is commonly ...
Permanent magnet brushless motor control based on ADRC
Directory of Open Access Journals (Sweden)
Li Xiaokun
2016-01-01
Full Text Available Permanent magnet brushless motor is a nonlinear system with multiple variables, the mathematical model of Permanent magnet brushless motor is difficult to establish, and since that the classic PID control is hard to precisely control the motor. Active disturbance rejection control (ADRC technique is a new nonlinear controller which does not depend on the system model. It is starting from the classic PID control, and establishing the loop control system by error negative feedback, the ESO(extended state observer observing system which comes from the observer theory of modern control theory to observe internal and external perturbations. ADRC inherits the advantages of PID with little overshoot, high convergence speed, high accuracy, strong anti-interference ability and other characteristics, and it has a strong disturbance adaptability and robustness as for the uncertainty perturbation and their internal disturbance of control objects. Therefore, This paper attempts to use Active disturbance rejection control(ADRC, in order to improve the control of permanent magnet brushless motor. In this design of control system, the simulation of the system is realized based on MATLAB, and then the discrete control algorithm is transplanted to the embedded system to control the permanent magnet brushless DC motor (PMBLDCM. The control system is implemented on the DSP-F28335 digital signal processor, and the DSP also provides the functions like voltage and current AD sampling, PWM driver generation, speed and rotor position calculation, etc. The simulation and experiment results indicate that, the system has good dynamic performance and anti-disturbance performance.
Improved transistor-controlled and commutated brushless DC motors for electric vehicle propulsion
Demerdash, N. A.; Miller, R. H.; Nehl, T. W.; Nyamusa, T. A.
1983-01-01
The development, design, construction, and testing processes of two electronically (transistor) controlled and commutated permanent magnet brushless dc machine systems, for propulsion of electric vehicles are detailed. One machine system was designed and constructed using samarium cobalt for permanent magnets, which supply the rotor (field) excitation. Meanwhile, the other machine system was designed and constructed with strontium ferrite permanent magnets as the source of rotor (field) excitation. These machine systems were designed for continuous rated power output of 15 hp (11.2 kw), and a peak one minute rated power output of 35 hp (26.1 kw). Both power ratings are for a rated voltage of 115 volts dc, assuming a voltage drop in the source (battery) of about 5 volts. That is, an internal source voltage of 120 volts dc. Machine-power conditioner system computer-aided simulations were used extensively in the design process. These simulations relied heavily on the magnetic field analysis in these machines using the method of finite elements, as well as methods of modeling of the machine power conditioner system dynamic interaction. These simulation processes are detailed. Testing revealed that typical machine system efficiencies at 15 hp (11.2 kw) were about 88% and 84% for the samarium cobalt and strontium ferrite based machine systems, respectively. Both systems met the peak one minute rating of 35 hp.
Energy Technology Data Exchange (ETDEWEB)
Lukaniszyn, M.; Jagiela, M.; Wrobel, R.
2003-04-16
A brushless, permanent magnet, three-phase disc-type salient-pole DC motor with co-axial flux in the stator is considered. Electromechanical properties of a basic eight-pole motor are compared with those for a 16-pole one of the same volume, in order to contrast the two potential candidates for variable-speed, low-cost drives. As a basis of the comparative analysis, 3D FEM magnetic field modelling and circuit analysis considering an electronic commutator are employed. Increasing the number of poles results in unfavourable raising in the switching frequency. The eight-pole motor construction has been shown in simulations to have higher efficiency and lower power losses than its 16-pole counterpart. (Author)
Mechanism For Adjustment Of Commutation Of Brushless Motor
Schaefer, Richard E.
1995-01-01
Mechanism enables adjustment of angular position of set of Hall-effect devices that sense instantaneous shaft angle of brushless dc motor. Outputs of sensors fed to commutation circuitry. Measurement of shaft angle essential for commutation; that is, application of voltage to stator windings must be synchronized with shaft angle. To obtain correct angle measurement for commutation, Hall-effect angle sensors positioned at proper reference angle. The present mechanism accelerates adjustment procedure and makes it possible to obtain more accurate indication of minimum-current position because it provides for adjustment while motor running.
Redundant speed control for brushless Hall effect motor
Nola, F. J. (Inventor)
1973-01-01
A speed control system for a brushless Hall effect device equipped direct current (D.C.) motor is described. Separate windings of the motor are powered by separate speed responsive power sources. A change in speed, upward or downward, because of the failure of a component of one of the power sources results in a corrective signal being generated in the other power source to supply an appropriate power level and polarity to one winding to cause the motor to be corrected in speed.
A Hybrid Model of a Brushless DC Motor
DEFF Research Database (Denmark)
Bendtsen, Jan Dimon; Hansen, Hans Brink; Kallesøe, Carsten Skovmose
2007-01-01
This paper presents a novel approach to modeling of a Brush-Less Direct Current Motor (BLDCM) driven by an inverter using hybrid systems theory. Hybrid systems combine continuous and discrete (event-based) dynamics, which is exactly the case in an inverter-driven BLDCM. The model presented...... in this work consists of a general automaton with discrete states, combined with a set of continuous dynamic equations describing the electro-mechanical behavior of the motor. One of the significant benefits of this strategy is that the model describes the motor under all possible operating conditions...
Rectifier Fault Diagnosis and Fault Tolerance of a Doubly Fed Brushless Starter Generator
Directory of Open Access Journals (Sweden)
Liwei Shi
2015-01-01
Full Text Available This paper presents a rectifier fault diagnosis method with wavelet packet analysis to improve the fault tolerant four-phase doubly fed brushless starter generator (DFBLSG system reliability. The system components and fault tolerant principle of the high reliable DFBLSG are given. And the common fault of the rectifier is analyzed. The process of wavelet packet transforms fault detection/identification algorithm is introduced in detail. The fault tolerant performance and output voltage experiments were done to gather the energy characteristics with a voltage sensor. The signal is analyzed with 5-layer wavelet packets, and the energy eigenvalue of each frequency band is obtained. Meanwhile, the energy-eigenvalue tolerance was introduced to improve the diagnostic accuracy. With the wavelet packet fault diagnosis, the fault tolerant four-phase DFBLSG can detect the usual open-circuit fault and operate in the fault tolerant mode if there is a fault. The results indicate that the fault analysis techniques in this paper are accurate and effective.
Research on Control System of Three - phase Brushless DC Motor for Electric Vehicle
Wang, Zhiwei; Jin, Hai; Guo, Jie; Su, Jie; Wang, Miao
2017-12-01
In order to study the three-phase brushless motor control system of electric vehicle, Freescale9S12XS128 chip is used as the control core, and the power MOSFET is used as the inverter device. The software is compiled by Codewarrior software. The speed control link adopts open-loop control, and the control chip collects the external sensor signal voltage Change control PWM signal output control three-phase brushless DC motor speed. The whole system consists of Hall position detection module, current detection module, power drive module and voltage detection module. The basic functions of three-phase brushless DC motor drive control are realized.
Demerdash, N. A. O.
1976-01-01
The modes of operation of the brushless d.c. machine and its corresponding characteristics (current flow, torque-position, etc.) are presented. The foundations and basic principles on which the preliminary numerical model is based, are discussed.
Comparing the Brushless DFIM to other Generator Systems for Wind Turbine Drive-Trains
National Research Council Canada - National Science Library
Strous, T.D; Shipurkar, U; Polinder, H; Ferreira, J.A
2016-01-01
In this paper, the brushless DFIM based wind turbine drive-train topology is compared to the DFIG based and PM generator based drive-train topologies, that are most commonly applied in modern wind turbines...
Shen, J.X.; Zhu, Z Q; Howe, D.
2004-01-01
The sensorless control of brushless machines by detecting the third harmonic back electromotive force is a relatively simple and potentially low-cost technique. However, its application has been reported only for brushless dc motors operating under normal commutation. In this paper, the utility of the method for the sensorless control of both brushless dc and ac motors, including operation in the flux-weakening mode, is demonstrated.
Low speed phaselock speed control system. [for brushless dc motor
Fulcher, R. W.; Sudey, J. (Inventor)
1975-01-01
A motor speed control system for an electronically commutated brushless dc motor is provided which includes a phaselock loop with bidirectional torque control for locking the frequency output of a high density encoder, responsive to actual speed conditions, to a reference frequency signal, corresponding to the desired speed. The system includes a phase comparator, which produces an output in accordance with the difference in phase between the reference and encoder frequency signals, and an integrator-digital-to-analog converter unit, which converts the comparator output into an analog error signal voltage. Compensation circuitry, including a biasing means, is provided to convert the analog error signal voltage to a bidirectional error signal voltage which is utilized by an absolute value amplifier, rotational decoder, power amplifier-commutators, and an arrangement of commutation circuitry.
Performance Analysis of a Brushless Double Fed Cage Induction Generator
Energy Technology Data Exchange (ETDEWEB)
Ruencos, F. [WEG S.A., Jaragua do Sul (Brazil); Carlson, R.; Oliveira, A.M.; Kuo-Peng, P.; Sadowski, N. [GRUCAD-UFSC, Florianopolis (Brazil)
2004-07-01
This paper analyses design and performance aspects of a brushless double fed cage induction generator as an economic and technical alternative to the classical wound rotor induction generator used in wind power generation. It focuses firstly on the machine operational characteristics and main design criteria and secondly on steady state and dynamic analytical and numerical models for efficient prediction of machine behavior. The analytical dynamic model is obtained by transforming the equations written in machine variables into equations written in an arbitrary reference frame. In the finite element approach the electrical machine is modeled in a 2D domain, using the Maxwell equations to formulate the field behavior and the FE method to discretize the domain of study. A prototype was built and tested to validate the simulation models and to verify the design criteria.
Disc rotors with permanent magnets for brushless DC motor
Hawsey, Robert A.; Bailey, J. Milton
1992-01-01
A brushless dc permanent magnet motor drives an autonomous underwater vehe. In one embodiment, the motor comprises four substantially flat stators in stacked relationship, with pairs of the stators axially spaced, each of the stators comprising a tape-wound stator coil, and first and second substantially flat rotors disposed between the spaced pairs of stators. Each of the rotors includes an annular array of permanent magnets embedded therein. A first shaft is connected to the first rotor and a second, concentric shaft is connected to the second rotor, and a drive unit causes rotation of the two shafts in opposite directions. The second shaft comprises a hollow tube having a central bore in which the first shaft is disposed. Two different sets of bearings support the first and second shafts. In another embodiment, the motor comprises two ironless stators and pairs of rotors mounted on opposite sides of the stators and driven by counterrotating shafts.
An improved iron loss estimation for permanent magnet brushless machines
Fang, D
1999-01-01
This paper presents an improved approach for predicting iron losses in permanent magnet brushless machines. The new approach is based on the fundamental concept that eddy current losses are proportional to the square of the time rate of change of flux density. Expressions are derived for predicting hysteresis and eddy current losses in the stator teeth and yoke. The so-called anomalous or excess losses, caused by the induced eddy current concentration around moving magnetic domain walls and neglected in the conventional core loss calculation, are also included in the proposed approach. In addition, the model is also capable of accounting for the stator skewing, if present. The core losses obtained from the proposed approach are compared with those measured on an existing PM motor at several operating speeds, showing very good agreement. (14 refs).
Directory of Open Access Journals (Sweden)
Jingang Bai
2012-01-01
Full Text Available A new type of brushless double rotor machine (BDRM is proposed in this paper. The BDRM is an important component in compound-structure permanent-magnet synchronous machine (CS-PMSM systems, which are promising for power-split hybrid electric vehicle (HEV applications. The BDRM can realize the speed adjustment between claw-pole rotor and permanent-magnet rotor without brushes and slip rings. The structural characteristics of the BDRM are described and its magnetic circuit model is built. Reactance parameters of the BDRM are deduced by an analytical method. It is found that the size characteristics of the BDRM are different from those of conventional machines. The new sizing and torque equations are analyzed and the theoretical results are used in the optimization process. Studies of the analytical magnetic circuit and finite element method (FEM model show that the BDRM tends to have high leakage flux and low power factor, and then the method to obtain high power factor is discussed. Furthermore, a practical methodology of the BDRM design is developed, which includes an analytical tool, 2D field calculation and performance evaluation by 3D field calculation. Finally, different topologies of the BDRM are compared and an optimum prototype is designed.
Graf, Rudolf F
1996-01-01
This series of circuits provides designers with a quick source for measuring circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listings
Graf, Rudolf F
1996-01-01
This series of circuits provides designers with a quick source for oscillator circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listing
Matsumoto, Raymond T. (Inventor); Higashi, Stanley T. (Inventor)
1976-01-01
A driver circuit which has low power requirements, a relatively small number of components and provides flexibility in output voltage setting. The driver circuit comprises, essentially, two portions which are selectively activated by the application of input signals. The output signal is determined by which of the two circuit portions is activated. While each of the two circuit portions operates in a manner similar to silicon controlled rectifiers (SCR), the circuit portions are on only when an input signal is supplied thereto.
Cheaper Synthesis Of Multipole-Brushless-dc-Motor Current
Alhorn, Dean C.; Howard, David E.
1994-01-01
Circuit converts output of single two-phase shaft-angle resolver to that of multi-speed three-phase shaft-angle resolver. Converter circuit applicable to generation of multispeed, multiphase shaft-angle-resolver signals from single two-phase shaft-angle resolver. Combination of converter circuit and single two-phase shaft-angle resolver offer advantages in cost, weight, size, and complexity. Design readily adaptable to two-phase motor.
James Webb Space Telescope Deployment Brushless DC Motor Characteristics Analysis
Tran, Ahn N.
2016-01-01
A DC motor's performance is usually characterized by a series of tests, which are conducted by pass/fail criteria. In most cases, these tests are adequate to address the performance characteristics under environmental and loading effects with some uncertainties and decent power/torque margins. However, if the motor performance requirement is very stringent, a better understanding of the motor characteristics is required. The purpose of this paper is to establish a standard way to extract the torque components of the brushless motor and gear box characteristics of a high gear ratio geared motor from the composite geared motor testing and motor parameter measurement. These torque components include motor magnetic detent torque, Coulomb torque, viscous torque, windage torque, and gear tooth sliding torque. The Aerospace Corp bearing torque model and MPB torque models are used to predict the Coulomb torque of the motor rotor bearings and to model the viscous components. Gear tooth sliding friction torque is derived from the dynamo geared motor test data. With these torque data, the geared motor mechanical efficiency can be estimated and provide the overall performance of the geared motor versus several motor operating parameters such as speed, temperature, applied current, and transmitted power.
Prospects for Brushless ac Motors with HTS Rotors
McCulloch, M. D.; Jim, K.; Kawai, Y.; Dew-Hughes, D.; Morgan, C.; Goringe, M. J.; Grovenor, C. R. M.
1997-03-01
There is a superconducting equivalent for every type of brushless ac motor; permanent magnet, reluctance, hysteresis and induction (squirrel cage) motor. The particular advantage of superconducting versions of these machines is that they are expected to provide much higher power densities than their conventional equivalents. The behaviour of superconducting rotors fabricated in the form of (a) squirrell cages from silver coated with melt-processed Bi-2212, (b) tubes cast centifugally from Bi-2212, and (c) small cylinders of melt-processed and seeded YBCO has been studied in rotating magnetic fields provided by conventional motor coils. Measurements of static torque, and values of dynamic torque deduced from angular velocity and acceleration have been used to characterise the potential performance of these embryonic machines. Two broad types of behaviour have been observed. In the Bi-2212 rotors the torque decreases with increasing rotor speed; this behaviour is believed due to flux creep. By contrast the strong-pinning YBCO rotors maintain a constant torque up to synchronous speed. Mathematical modelling of flux penetration and distribution within the rotors is able to reproduce both types of the observed behaviour. Power densities some 5 to 10 times that of conventional machines are predicted to be achievable in optimised prototype machines.
Dynamic modeling of brushless dc motors for aerospace actuation
Demerdash, N. A.; Nehl, T. W.
1980-01-01
A discrete time model for simulation of the dynamics of samarium cobalt-type permanent magnet brushless dc machines is presented. The simulation model includes modeling of the interaction between these machines and their attached power conditioners. These are transistorized conditioner units. This model is part of an overall discrete-time analysis of the dynamic performance of electromechanical actuators, which was conducted as part of prototype development of such actuators studied and built for NASA-Johnson Space Center as a prospective alternative to hydraulic actuators presently used in shuttle orbiter applications. The resulting numerical simulations of the various machine and power conditioner current and voltage waveforms gave excellent correlation to the actual waveforms collected from actual hardware experimental testing. These results, numerical and experimental, are presented here for machine motoring, regeneration and dynamic braking modes. Application of the resulting model to the determination of machine current and torque profiles during closed-loop actuator operation were also analyzed and the results are given here. These results are given in light of an overall view of the actuator system components. The applicability of this method of analysis to design optimization and trouble-shooting in such prototype development is also discussed in light of the results at hand.
Research of subdivision driving technology for brushless DC motors in optical fiber positioning
Kan, Yi; Gu, Yonggang; Zhu, Ye; Zhai, Chao
2016-07-01
In fiber spectroscopic telescopes, optical fiber positioning units are used to position thousands of fibers on the focal plane quickly and precisely. Stepper motors are used in existing units, however, it has some inherent deficiencies, such as serious heating and low efficiency. In this work, the universally adopted subdivision driving technology for stepper motors is transplanted to brushless DC motors. It keeps the advantages of stepper motors such as high positioning accuracy and resolution, while overcomes the disadvantages mentioned above. Thus, this research mainly focuses on develop a novel subdivision driving technology for brushless DC motor. By the proving of experiments of online debug and subdivision speed and position, the proposed brushless DC motor subdivision technology can achieve the expected functions.
BRUSHLESS VALVE ELECTRIC DRIVE WITH MINIMUM EQUIPMENT EXCESS FOR AUTONOMOUS FLOATING VEHICLE
Directory of Open Access Journals (Sweden)
Ya. B. Volyanskaya
2017-08-01
Full Text Available Purpose. Development of a brushless valve electric drive with a minimum apparatus excess for an autonomous floating vehicle. Methodology. The construction of models of an automated electric drive with a contactless DC motor and the subsequent technical implementation of such automated electric drive under various control methods are possible using coordinate transformations of differential equations describing the electric motor under the assumed assumptions. Results. The analysis of the current state of an automated electric drive with a brushless DC motor in a special technique is carried out, possible directions for the improvement of automated electric drives are determined. A simple technical solution of an automated electric drive with a brushless DC motor was proposed and its mathematical model for an electric drive of an automatic floating vehicle with improved technical and economic parameters was developed. Model of an automated electric drive with a brushless DC motor are carried out. Originality. A simple technical solution for the construction of an automated electric drive with a brushless DC motor is proposed, which excludes the use of intermediate computation of coordinates and an expensive encoder. Practical value. Model of the proposed scheme of an automated electric drive with a minimum hardware redundancy, which confirmed the operability of the proposed solution, were carried out. Analysis of the dynamic and static characteristics of the proposed scheme of an automated asynchronous electric drive with a brushless DC motor with a simplified rotor position sensor has made it possible to determine the maximum speed control range with an allowable level of its pulsations.
Modeling and control of a brushless DC axial flow ventricular assist device.
Giridharan, Guruprasad A; Skliar, Mikhail; Olsen, Donald B; Pantalos, George M
2002-01-01
This article presents an integrated model of the human circulatory system that incorporates circulatory support by a brushless DC axial flow ventricular assist device (VAD), and a feedback VAD controller designed to maintain physiologically sufficient perfusion. The developed integrated model combines a network type model of the circulatory system with a nonlinear dynamic model of the brushless DC pump We show that maintaining a reference differential pressure between the left ventricle and aorta leads to adequate perfusion for different pathologic cases, ranging from normal heart to left heart asystole, and widely varying physical activity scenarios from rest to exercise.
Directory of Open Access Journals (Sweden)
Bo Long
2013-12-01
Full Text Available Regenerative braking provides an effective way of extending the driving range of battery powered electric vehicles (EVs. This paper analyzes the equivalent power circuit and operation principles of an EV using regenerative braking control technology. During the braking period, the switching sequence of the power converter is controlled to inverse the output torque of the three-phase brushless direct-current (DC motor, so that the braking energy can be returned to the battery. Compared with the presented methods, this technology can achieve several goals: energy recovery, electric braking, ultra-quiet braking and extending the driving range. Merits and drawbacks of different braking control strategy are further elaborated. State-space model of the EVs under energy-regenerative braking operation is established, considering that parameter variations are unavoidable due to temperature change, measured error, un-modeled dynamics, external disturbance and time-varying system parameters, a sliding mode robust controller (SMRC is designed and implemented. Phase current and DC-link voltage are selected as the state variables, respectively. The corresponding control law is also provided. The proposed control scheme is compared with a conventional proportional-integral (PI controller. A laboratory EV for experiment is setup to verify the proposed scheme. Experimental results show that the drive range of EVs can be improved about 17% using the proposed controller with energy-regeneration control.
Analysis of brushless DC generator incorporating an axial field coil
Energy Technology Data Exchange (ETDEWEB)
Moradi, Hassan, E-mail: H_moradi@sbu.ac.i [Department of Electrical and Computer Engineering, Shahid Beheshti University, GC, Tehran (Iran, Islamic Republic of); Afjei, E. [Department of Electrical and Computer Engineering, Shahid Beheshti University, GC, Tehran (Iran, Islamic Republic of)
2011-07-15
Highlights: {yields} Magnetic analysis and experiment of a three-phase field assisted BLDC generator. {yields} Confirm the accuracy of the predicted flux-linkage by 2-D FE analysis. {yields} Confirm the accuracy of the FE analysis results by coupling the FE and BE method. {yields} Control the output voltage to a desired level by control the amplitude of the I{sub f}. {yields} Compatible with any application that requires variable speed operation. -- Abstract: This paper describes the magnetic analysis and experiment of a three-phase field assisted brushless DC (BLDC) generator. Unlike conventional BLDC generators, the permanent magnet is replaced with an assisted field winding. The stator and rotor are constructed with two dependent magnetically sets, in which each stator set includes nine salient poles with coil windings, and the rotor comprises of six salient poles. Other pole combinations also are possible. This construction is similar to a homopolar inductor alternator. The DC current in the assisted field winding produces axial flux which makes the rotor magnetically polarized at its ends. The magnetic field flows axially through the rotor shaft and closes through the stator teeth and the machine housing. To evaluate the generator performance, two types of analysis, namely the numerical technique and the experimental study have been utilized. In the numerical analysis, 2-D finite element (FE) analysis has been carried out using a MagNet CAD package (Infolytica Corporation Ltd.), to confirm the accuracy of the predicted flux-linkage characteristics, whereas in the experimental study, a prototype BLDC generator was constructed for verifying the actual performance. Furthermore, the evaluation method based on a hybrid numerical method coupling the finite element (FE) analysis and boundary element (BE) method, has been carried out to confirm the accuracy of the 2-D FE analysis simulation results. It provides not only confirmations of the investigation in results
Anti-control of chaos of single time-scale brushless DC motor.
Ge, Zheng-Ming; Chang, Ching-Ming; Chen, Yen-Sheng
2006-09-15
Anti-control of chaos of single time-scale brushless DC motors is studied in this paper. In order to analyse a variety of periodic and chaotic phenomena, we employ several numerical techniques such as phase portraits, bifurcation diagrams and Lyapunov exponents. Anti-control of chaos can be achieved by adding an external constant term or an external periodic term.
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A.V. Matyuschenko
2015-03-01
Full Text Available By means of JMAG-Designer 12 the author performed a comparative analysis of the calculation of the EMF, cogging torque and electromagnetic torque of brushless motor with permanent magnets in two-dimensional and three-dimensional formulation of the problem.
Method and apparatus for sensorless operation of brushless permanent magnet motors
Sriram, T.V.
1998-04-14
A sensorless method and apparatus for providing commutation timing signals for a brushless permanent magnet motor extracts the third harmonic back-emf of a three-phase stator winding and independently cyclically integrates the positive and negative half-cycles thereof and compares the results to a reference level associated with a desired commutation angle. 23 figs.
Comparison of Nested-Loop Rotors in Brushless Doubly-Fed Induction Machines
Wang, X.; Liu, D.; Lahaye, D.J.P.; Polinder, H.; Ferreira, J.A.
2017-01-01
The brushless doubly-fed induction machine (DFIM) has great potential as a variable-speed generator for wind turbine applications. This special machine has a richer space-harmonic spectrum due to its special nested-loop rotor construction compared with conventional induction machines. It may result
Synchronization of the Fractional-Order Brushless DC Motors Chaotic System
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Shiyun Shen
2016-01-01
Full Text Available Based on the extension of Lyapunov direct method for nonlinear fractional-order systems, chaos synchronization for the fractional-order Brushless DC motors (BLDCM is discussed. A chaos synchronization scheme is suggested. By means of Lyapunov candidate function, the theoretical proof of chaos synchronization is addressed. The numerical results show that the chaos synchronization scheme is valid.
Synchronization of the Fractional-Order Brushless DC Motors Chaotic System
Shiyun Shen; Ping Zhou
2016-01-01
Based on the extension of Lyapunov direct method for nonlinear fractional-order systems, chaos synchronization for the fractional-order Brushless DC motors (BLDCM) is discussed. A chaos synchronization scheme is suggested. By means of Lyapunov candidate function, the theoretical proof of chaos synchronization is addressed. The numerical results show that the chaos synchronization scheme is valid.
Novel Motion Sensorless Control of Single Phase Brushless D.C. PM Motor Drive, with experiments
DEFF Research Database (Denmark)
Lepure, Liviu Ioan; Boldea, Ion; Andreescu, Gheorghe Daniel
2010-01-01
A motion sensorless control for single phase permanent magnet brushless d.c. (PM-BLDC) motor drives, based on flux integration and prior knowledge of the PM flux/position characteristic is proposed here and an adequate correction algorithm is adopted, in order to increase the robustness to noise...
Method and apparatus for sensorless operation of brushless permanent magnet motors
Sriram, Tillasthanam V.
1998-01-01
A sensorless method and apparatus for providing commutation timing signals for a brushless permanent magnet motor extracts the third harmonic back-emf of a three-phase stator winding and independently cyclically integrates the positive and negative half-cycles thereof and compares the results to a reference level associated with a desired commutation angle.
Improved Analytical Model of a Permanent-Magnet Brushless DC Motor
Kumar, P.; Bauer, P.
2008-01-01
In this paper, we develop a comprehensive model of a permanent-magnet brushless DC (BLDC) motor. An analytical model for determining instantaneous air-gap field density is developed. This instantaneous field distribution can be further used to determine the cogging torque, induced back electromotive
Comparing the Brushless DFIM to other Generator Systems for Wind Turbine Drive-Trains
Strous, T.D.; Shipurkar, U.; Polinder, H.; Ferreira, J.A.
2016-01-01
In this paper, the brushless DFIM based wind turbine drive-train topology is compared to the DFIG based and PM generator based drive-train topologies, that are most commonly applied in modern wind turbines. The comparison will be based on a 3:2MW case study wind turbine. By using FE based
Comparison of solar panel cooling system by using dc brushless fan and dc water
Irwan, Y. M.; Leow, W. Z.; Irwanto, M.; M, Fareq; Hassan, S. I. S.; Safwati, I.; Amelia, A. R.
2015-06-01
The purpose of this article is to discuss comparison of solar panel cooling system by using DC brushless fan and DC water pump. Solar photovoltaic (PV) power generation is an interesting technique to reduce non-renewable energy consumption and as a renewable energy. The temperature of PV modules increases when it absorbs solar radiation, causing a decrease in efficiency. A solar cooling system is design, construct and experimentally researched within this work. To make an effort to cool the PV module, Direct Current (DC) brushless fan and DC water pump with inlet/outlet manifold are designed for constant air movement and water flow circulation at the back side and front side of PV module representatively. Temperature sensors were installed on the PV module to detect temperature of PV. PIC microcontroller was used to control the DC brushless fan and water pump for switch ON or OFF depend on the temperature of PV module automatically. The performance with and without cooling system are shown in this experiment. The PV module with DC water pump cooling system increase 3.52%, 36.27%, 38.98%in term of output voltage, output current, output power respectively. It decrease 6.36 °C compare than to PV module without DC water pump cooling system. While DC brushless fan cooling system increase 3.47%, 29.55%, 32.23%in term of output voltage, output current, and output power respectively. It decrease 6.1 °C compare than to PV module without DC brushless fan cooling system. The efficiency of PV module with cooling system was increasing compared to PV module without cooling system; this is because the ambient temperature dropped significantly. The higher efficiency of PV cell, the payback period of the system can be shorted and the lifespan of PV module can also be longer.
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Abolfazl Halvaei Niasar
2017-12-01
Full Text Available This paper presents a simple and low-cost method to capture maximum power throughput of permanent magnet brushless DC (BLDC generator. Conventional methods of rectification are based on passive converters, and because the current waveform cannot be controlled as ideal waveform, a highly distorted current is drawn from brushless generator. It leads to lower power factor and reduces the efficiency and power per ampere capability. So, in this study an active six-witch power converter is employed and based on the phase back-EMF voltage, an optimum current waveform is generated. The phase currents are controlled inphase to phase voltages and their magnitudes are adjusted to regulate the DC-link voltage. Proposed control theory is verified by simulations for BLDC generator and permanent magnet synchronous generator (PMSG. Moreover, some experimental results are given to demonstrate the theoretical and simulation results.
On-Line Tracking Controller for Brushless DC Motor Drives Using Artificial Neural Networks
Rubaai, Ahmed
1996-01-01
A real-time control architecture is developed for time-varying nonlinear brushless dc motors operating in a high performance drives environment. The developed control architecture possesses the capabilities of simultaneous on-line identification and control. The dynamics of the motor are modeled on-line and controlled using an artificial neural network, as the system runs. The control architecture combines the experience and dependability of adaptive tracking systems with potential and promise of the neural computing technology. The sensitivity of real-time controller to parametric changes that occur during training is investigated. Such changes are usually manifested by rapid changes in the load of the brushless motor drives. This sudden change in the external load is simulated for the sigmoidal and sinusoidal reference tracks. The ability of the neuro-controller to maintain reasonable tracking accuracy in the presence of external noise is also verified for a number of desired reference trajectories.
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Rizqi Andry Ardiansyah
2017-08-01
Full Text Available Many industrial applications use servo motor because of its accuracy and user-friendly, but by using it in an application, a higher cost is required. To make an actuator with good precision and universal purpose but with lower cost, a position control system for brushless dc motor was built. To achieve a better precision in the position control for brushless DC motor, the system is utilized with a microcontroller ATmega 2560, an absolute encoder as a position sensor, and also Proportional-Derivative closed-loop control algorithm. In the final test, we obtained that the system worked well on average angular speed about 3.88º/ms and angle tolerance about 1º.
Comparing the Brushless DFIM to other Generator Systems for Wind Turbine Drive-Trains
Strous, Tim D.; Shipurkar, Udai; Polinder, Henk; Ferreira, Jan A.
2016-09-01
In this paper, the brushless DFIM based wind turbine drive-train topology is compared to the DFIG based and PM generator based drive-train topologies, that are most commonly applied in modern wind turbines. The comparison will be based on a 3.2 MW case study wind turbine. By using FE based multi-objective optimization, optimized generator designs for the different topologies are generated. Then the capital expenditures of the resulting drive-train topologies are calculated and compared. Additionally, wind turbine drive-train configurations with 1, 2 and 3 stage gearboxes as well as a direct-drive configuration are taken into account. The resulting comparison shows that the brushless DFIM based drive-train with a 2 stage gearbox configuration provides a feasible alternative in commercial wind turbine drive-train applications.
Optimal PID control of a brushless DC motor using PSO and BF techniques
Directory of Open Access Journals (Sweden)
H.E.A. Ibrahim
2014-06-01
Full Text Available This paper presents a Particle Swarm Optimization (PSO technique and bacterial foraging (BF technique for determining the optimal parameters of (PID controller for speed control of a brushless DC motor (BLDC where the (BLDC motor is modeled in simulink in Matlab. The proposed technique was more efficient in improving the step response characteristics as well as reducing the steady-state error, rise time, settling time and maximum overshoot.
Dynamic Performance of a Single Machine Brushless DFIG during Wind Speed Variation
Mona N. Eskander; Saleh, Mahmoud A.; Maged N. F. Nashed
2015-01-01
In this paper, the dynamic performance of the specially-designed Single Machine Brushless Doubly-Fed Induction Generator "SM-BDFIG" coupled to variable speed wind turbine is investigated. The rotor voltage of the SM-BDFIG during super-synchronous operation is used to charge a number of batteries, connected to the rotor via a 3- phase bridge rectifier. The number of charged battery cells are changed, by parallel and series connections, according to the wind speed variat...
System and Method for Determining Rate of Rotation Using Brushless DC Motor
Howard, David E. (Inventor); Smith, Dennis A. (Inventor)
2000-01-01
A system and method are provided for measuring rate of rotation. A brushless DC motor is rotated and produces a back electromagnetic force (emf) on each winding thereof. Each winding's back-emf is squared. The squared outputs associated with each winding are combined, with the square root being taken of such combination, to produce a DC output proportional only to the rate of rotation of the motor's shaft.
Fuzzy controllers in the control system of a brushless electric motor using HIL technology
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Kalach Gennady
2017-01-01
Full Text Available This article proposes a method for creation of a control system for a brushless electric motor based on a fuzzy logic apparatus. The use of a fuzzy controller in this case can increase stability and improve the quality of the system under consideration, which was implemented in the Simulink environment using HIL technology. This technology increases the chances of successfully passing the test phase, considering the control system in prototype.
Rate of rotation measurement using back-EMFS associated with windings of a brushless DC motor
Howard, David E. (Inventor)
2000-01-01
A system and method are provided for measuring rate of rotation. A brushless DC motor is rotated and produces a back electromagnetic force (emf) on each winding thereof. Each winding's back-emf is integrated and multiplied by the back-emf associated with an adjacent winding. The multiplied outputs associated with each winding are combined to produce a directionally sensitive DC output proportional only to the rate of rotation of the motor's shaft.
Rectifier Fault Diagnosis and Fault Tolerance of a Doubly Fed Brushless Starter Generator
Liwei Shi; Zhou Bo
2015-01-01
This paper presents a rectifier fault diagnosis method with wavelet packet analysis to improve the fault tolerant four-phase doubly fed brushless starter generator (DFBLSG) system reliability. The system components and fault tolerant principle of the high reliable DFBLSG are given. And the common fault of the rectifier is analyzed. The process of wavelet packet transforms fault detection/identification algorithm is introduced in detail. The fault tolerant performance and output voltage experi...
Computer Simulation and Operating Characteristics of a Three-Phase Brushless Synchronous Generator
Cingoski, Vlatko; Mikami, Mitsuru; Inoue, Kenji; Kaneda, Kazufumi; Yamashita, Hideo
1998-01-01
This paper deals with numerical computation and simulation of the operating conditions of a three-phase brushless synchronous generator. A voltage driven nonlinear time-periodic finite element analysis is utilized to compute accurately the magnetic field distribution and the induced voltage and currents. The computation procedure is briefly addressed followed by the computed results and their comparison with experimental ones. The agreement between results is very good verifying the computati...
High torque density permanent magnet brushless machines with similar slot and pole numbers
Ishak, D.; Zhu, Z. Q.; Howe, D.
2004-05-01
The paper describes a theoretical and experimental investigation into the electromagnetic performance of permanent magnet brushless machines having similar slot and pole numbers. Finite element analysis is employed to predict the airgap flux density distribution, the cogging torque and emf waveforms, and the winding inductances. It is shown that such machines exhibit a high torque density and is conducive to fault tolerance. The results are validated on two experimental motors.
Comparison of Nested-Loop Rotors in Brushless Doubly-Fed Induction Machines
Wang, X.; Liu, D; Lahaye, D.J.P.; Polinder, H.; Ferreira, J. A.
2017-01-01
The brushless doubly-fed induction machine (DFIM) has great potential as a variable-speed generator for wind turbine applications. This special machine has a richer space-harmonic spectrum due to its special nested-loop rotor construction compared with conventional induction machines. It may result in higher iron losses, higher torque ripple and more time-harmonics adding to the grid total harmonic distortion (THD). This paper applies the 2D finite element (FE) model to investigate several di...
Characterization of the Rotor Magnetic Field in a Brushless Doubly Fed Induction Machine.
Blázquez García, Francisco; Veganzones Nicolas, Carlos; Ramírez Prieto, Dionisio; Platero Gaona, Carlos Antonio
2009-01-01
The large increase in wind generation could improve the final development of wind systems with brushless doubly-fed induction machines (BDFIM) as an alternative to the doubly-fed asynchronous machines. For this reason, a detailed study of several aspects of the BDFIM design, as well as of its rotor configuration, is absolutely essential. In this paper, the authors present an alternative formulation of the BDFIM operating principle in synchronous mode. Besides the basic equation of the machine...
Jovanović, Milutin G.
2006-01-01
The brushless doubly-fed machine (BDFM) allows the use of a partially rated inverter and represents an attractive cost-effective candidate for variable speed applications with limited speed ranges. In its induction machine form (BDFIM), the BDFM has significant rotor losses and poor efficiency due to the cage rotor design which makes the machine dynamic models heavily parameter dependent and the resulting controller configuration complicated and difficult to implement. A reluctance version of...
E. Kaliappan; C. Chellamuthu
2012-01-01
Problem statement: In this study, a simplified modeling and experimental analysis of Permanent Magnet Brushless DC (PMBLDC) motors for Sensorless operation using MATLAB/SIMULINK. This model provides a mechanism for monitoring and controlling the voltage, current, speed and torque response. Approach: BLDC motor is modeled as sub-blocks. The inverter and switching function are implemented as S-function builder block. The Sensorless scheme employs direct back emf based zero crossing detection te...
Design and Optimization of Permanent Magnet Brushless Machines for Electric Vehicle Applications
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Weiwei Gu
2015-12-01
Full Text Available In this paper, by considering and establishing the relationship between the maximum operating speed and d-axis inductance, a new design and optimization method is proposed. Thus, a more extended constant power speed range, as well as reduced losses and increased efficiency, especially in the high-speed region, can be obtained, which is essential for electric vehicles (EVs. In the first step, the initial permanent magnet (PM brushless machine is designed based on the consideration of the maximum speed and performance specifications in the entire operation region. Then, on the basis of increasing d-axis inductance, and meanwhile maintaining constant permanent magnet flux linkage, the PM brushless machine is optimized. The corresponding performance of the initial and optimal PM brushless machines are analyzed and compared by the finite-element method (FEM. Several tests are carried out in an EV simulation model based on the urban dynamometer driving schedule (UDDS for evaluation. Both theoretical analysis and simulation results verify the validity of the proposed design and optimization method.
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Adhika Prajna Nandiwardhana
2017-01-01
Full Text Available Penggunaan motor brushless DC telah banyak digunakan dalam berbagai bidang seperti peralatan rumah tangga maupun industri dikarenakan motor ini memiliki struktur yang sederhana, efisiensi dan torsi yang tinggi, serta menggunakan konsep komutasi elektris yang berbeda dari motor DC lainnya. Namun pengoperasian pada umumnya yang menggunakan sumber AC, penyearah serta inverter membuat tingginya nilai harmonisa arus (THD sebesar 73,33% dan power factor sebesar 0,803 dimana nilai ini kurang baik dalam pengaplikasiannya. Pada penelitian ini akan dikaji mengenai proses power factor correction yang mereduksi harmonisa arus (THD sumber AC dengan menggunakan zeta converter dalam pengaplikasian motor brushless DC, serta pengoperasian motor dengan mengamati respon motor terhadap kecepatan referensi yang berubah-ubah dan mengamati kestabilan motor terhadap pembebanan yang bervariasi. Dalam menerapkan metode yang dilakukan pada penelitian ini, pengoperasian motor brushless DC yang telah dirancang dapat bekerja dengan baik meliputi respon motor yang dapat mengikuti kecepatan referensi yang berubah-ubah, serta kestabilan motor dalam mempertahankan kecepatannya pada pembebanan yang bervariasi. Proses power factor correction dapat meningkatkan kualitas daya pada berbagai kecepatan dan mode penerapan yang berbeda-beda, dimana peningkatan tersebut membuktikan kinerja yang baik dalam sistem ini dan memiliki nilai kualitas daya yang baik.
Estimation parameters and black box model of a brushless DC motor
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José A. Becerra-Vargas
2014-08-01
Full Text Available The modeling of a process or a plant is vital for the design of its control system, since it allows predicting its dynamic and behavior under different circumstances, inputs, disturbances and noise. The main objective of this work is to identify which model is best for a permanent magnet brushless DC specific motor. For this, the mathematical model of a DC motor brushless PW16D, manufactured by Golden Motor, is presented and compared with its black box model; both are derived from experimental data. These data, the average applied voltage and the angular velocity, are acquired by a data acquisition card and imported to the computer. The constants of the mathematical model are estimated by a curve fitting algorithm based on non-linear least squares and pattern search using computational tool. To estimate the mathematical model constants by non-linear least square and search pattern, a goodness of fit of 84.88% and 80.48% respectively was obtained. The goodness of fit obtained by the black box model was 87.72%. The mathematical model presented slightly lower goodness of fit, but allowed to analyze the behavior of variables of interest such as the power consumption and the torque applied to the motor. Because of this, it is concluded that the mathematical model obtained by experimental data of the brushless motor PW16D, is better than its black box model.
The Application of Parameter Space Design Method for Generator Excitation Control
Iki, Hiroyuki; Yoshimura, Shyuta; Uriu, Yosihisa
Recently, control engineering changes from classical control theory to modern control theory, and analogue to digital. However, as a matter of fact, the sensitivity adjustment of the parameters using Bode diagram require many time and works. In this paper, the tool of Matlab/Simulink that adjusted the AVR control parameter of the PI control type brushless and Thyristor excitation method by using the technique for based on the parameter space planning method by QE was made. Moreover, the adjustment of the sensitivity parameter of the excitation control method intended for the dynamic stability level area in Single Machine Infinite Bus is examined with the tool.
Multon, Bernard; Hoang, Emmanuel; Camus, François
1993-01-01
International audience; In this paper, we carried out a dimensional parametric analysis of average torque and copper losses in the case of two synchronous brushless motors. These motors were, on the one hand, a Permanent-Magnet Brushless DC (PMBLDC) motor supplied by quasi-square currents, with surface magnet mounted rotor and trapezoidal e.m.f. waveform, and, on the other hand, a Doubly Salient Variable Reluctance (DSVR) motor fed by quasi-square currents at low speed, and by full wave squar...
A flux-mnemonic permanent magnet brushless motor for electric vehicles
Yu, Chuang; Chau, K. T.; Liu, Xinhua; Jiang, J. Z.
2008-04-01
In this paper, a new permanent magnet (PM) brushless motor is proposed for electric vehicles. The key is to incorporate the concept of memory motors, namely, the online tunable flux-mnemonic PMs, into the stator doubly fed doubly salient PM motor, hence achieving effective air-gap flux control. By further employing the outer-rotor and double-layer-stator topology, the proposed motor takes the definite advantages of compact structure, low armature reaction, and direct-drive capability. Increasingly, this motor can offer the unique features of pole dropping and pole reversing. Finite element analysis and, hence, computer simulation are given to verify the validity of the proposed motor.
Comparing the Brushless DFIM to other Generator Systems for Wind Turbine Drive-Trains
Strous, T.D.; Shipurkar, U.; Polinder, H.; Ferreira, J. A.
2016-01-01
In this paper, the brushless DFIM based wind turbine drive-train topology is compared to the DFIG based and PM generator based drive-train topologies, that are most commonly applied in modern wind turbines. The comparison will be based on a 3:2MW case study wind turbine. By using FE based multi-objective optimization, optimized generator designs for the dierent topologies are generated. Then the capital expenditures of the resulting drive-train topologies are calculated and compared. Addition...
POSITION CONTROL OF BRUSHLESS DC MOTOR BASED ON DIGITAL SIGNAL PROCESSING
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Çetin GENÇER
2006-01-01
Full Text Available Brushless DC Motors (BLDC have been used widely high performance control systems which are depended on to development of power electronic and control technology. In these motors to fed commutated supply, the control of position without oscilation has been required. In this study, position control of BLDC with digital signal processing has been implemented by a proportional-derivative (PD controller because of its simple structure. It has been seen that the controller which is proposed from simulation and experimental studies, has a quick dynamic responce with nonoscillation.
Aspects Concerning the Torque Ripple Control of the Brushless DC Motor
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BALUTA, G.
2013-05-01
Full Text Available This paper deals with two advanced numerical structures to control the electromagnetic torque ripple of Brushless Direct Current Motors (BLDCM, indirectly achieved by phase currents control and directly by the Direct Torque Control (DTC technique. In DTC there was implemented an observer to increase the rudimentary transducer resolution, containing three Hall Effect sensors. The experimental results describe the evolution of torque in both situations of control and are obtained by applying a control strategy for an electric drive system with BLDCM with trapezoidal Back-EMF in Two-Phase Mode.
A new rotor speed observer for stand-alone brushless doubly-fed induction generators
DEFF Research Database (Denmark)
Liu, Yi; Xu, Wei; Long, Teng
2017-01-01
Brushless doubly-fed induction generator (BDFIG) is a new type of ac induction machine and can be used for both grid-connected and stand-alone power generation. The conventional control methods for the BDFIG almost all rely on the encoder, which brings many limitations in terms of cost, complexity......, reliability, and so on. This paper presents a new rotor speed observer (RSO) for the encoderless operation of the stand-alone BDFIG, which is based on a rotor position phase-locked loop (PLL) and a second-order generalized integrator (SOGI) and independent of any other machine parameters except for the pole...
A General Model for Describing the Performance of Brushless Doubly-Fed Induction Machines
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S. M. Allam
2010-12-01
Full Text Available This paper presents a generalized model, by which the dynamic and steady-state behaviour of the Brushless Doubly-Fed Induction Machine (BDFIM can be precisely predicted. The investigated doubly-fed machine has two sets of three-phase stator windings with different pole numbers. The rotor is a squirrel-cage type with a simple modification in order to support the two air-gap rotating fields that are produced by the stator windings and have different pole numbers. The machine model is derived in the qdo-axis variables. The qdoaxes are attached to rotor and hence, it rotates at the rotor speed (
Spin coater based on brushless dc motor of hard disk drivers.
Bianchi, Rodrigo Fernando; Panssiera, M. F.; Lima, J. P. H.; Yagura, L.; Andrade, A. M.; Faria, Roberto Mendonça
2006-01-01
We have developed a novel programmable, low cost, spin coater to be used for applications where flat substrates are coated with an uniform thin layer of a desirable material. The equipment is built with dc brushless motor present in most of the hard disk drivers (HDDs). The system offers manual control, wide speed range (from 0 to 10,000 rpm), spin speed stability and compact size. The paper also describes the use of such equipment for the fabrication of thin poly(o-methoxyaniline) (POMA) fil...
A Novel Coaxial Magnetic Gear and Its Integration With Permanent-Magnet Brushless Motor
DEFF Research Database (Denmark)
Zhang, Xiaoxu; Liu, Xiao; Chen, Zhe
2016-01-01
magnetic gear (CMG), which will not increase the mechanical complexity after integration with a permanent magnet (PM) brushless machine. The prominent feature of the proposed CMG is the introduction of the stator with modulating teeth, which function as the same as the modulating pole......A magnetic geared machine (MGM) is believed to be a promising candidate for high-torque direct-drive application. One of the key issues for developing MGMs is how to resolve the contradiction between the good performance and the complex structure. This paper aims at proposing a novel coaxial...
Novel Position and Speed Estimator for PM Single Phase Brushless D.C. Motor Drives
DEFF Research Database (Denmark)
Lepure, Liviu I.; Andreescu, Gheorghe-Daniel; Iles, Doris
2010-01-01
A novel position and speed estimator for single phase permanent magnet brushless d.c. (PMBLDC) motor drives, based on flux integration and prior knowledge of ΨPM (θ) is proposed here and an adequate correction algorithm is adopted in order to increase the robustness to noise and to reduce...... the sensitivity to accuracy of flux linkage estimation. A speed and current close loop control is employed based on the Hall signal and the motor is controlled at different speeds in order to validate the proposed estimation algorithm with satisfying results. The position correction effect is analyzed...
Lim, Edward C
1974-01-01
Excited States, Volume I reviews radiationless transitions, phosphorescence microwave double resonance through optical spectra in molecular solids, dipole moments in excited states, luminescence of polar molecules, and the problem of interstate interaction in aromatic carbonyl compounds. The book discusses the molecular electronic radiationless transitions; the double resonance techniques and the relaxation mechanisms involving the lowest triplet state of aromatic compounds; as well as the optical spectra and relaxation in molecular solids. The text also describes dipole moments and polarizab
DEFF Research Database (Denmark)
to the intersecting streams of goods, people, ideas, and money as they circulate between African migrants and their kin who remain back home. They also show the complex ways that emotions become entangled in these exchanges. Examining how these circuits operate in domains of social life ranging from child fosterage...... to binational marriages, from coming-of-age to healing and religious rituals, the book also registers the tremendous impact of state officials, laws, and policies on migrant experience. Together these essays paint an especially vivid portrait of new forms of kinship at a time of both intense mobility and ever...
Developing micro DC-brushless motor driver and position control for fiber positioners
Jenni, Laurent; Hörler, Philipp; Makarem, Laleh; Kneib, Jean-Paul; Gillet, Denis; Bleuler, Hannes; Bouri, Mohamed; Prada, Francisco; De Rivera, Guillermo; Sanchez, Justo
2014-07-01
In the large-scale, Dark Energy Spectroscopic Instrument (DESI), thousands of fiber positioners will be used. Those are robotic positioners, with two axis, and having the size of a pen. They are tightly packed on the focal plane of the telescope. Dedicated micro-robots have been developed and they use 4mm brushless DC motors. To simplify the implementation and reduce the space occupancy, each actuator will integrate its own electronic control board. This board will be used to communicate with the central trajectory generator, manage low level control tasks and motor current feeding. In this context, we present a solution for a highly compact electronic. This electronic is composed of two layers. The first is the power stage that can drive simultaneously two brushless motors. The second one consists of a fast microcontroller and deals with different control tasks: communication, acquisition of the hall sensor signals, commutation of the motors phases, and performing position and current regulation. A set of diagnostic functions are also implemented to detect failure in the motors or the sensors, and to sense abnormal load change that may be the result of two robots colliding.
Peacock, W. M.
1971-01-01
The ITOS with an improved attitude control system is described. A Hall generator brushless dc torque motor will replace the brush dc torque motor on ITOS-I and ITOS-A (NOAA-1). The four attitude horizon sensors will be replaced with two CO2 sensors for better horizon definition. An earth horizon splitting technique will be used to keep the earth facing side of the satellite toward earth even if the desired circular orbit is not achieved. The external appearance of the pitch control subsystem differs from TIROS-M (ITOS-1) and ITOS-A (NOAA-1) in that two instead of one pitch control electronics (PCE) boxes are used. Two instead of four horizon sensors will be used and one instead of two mirrors will be used for sensor scanning. The brushless motor will eliminate the requirement for brushes, strain gages and the telemetry for the brush wear. A single rotating flywheel, supported by a single bearing provides the gyroscopic stability and the required momentum interchange to keep one side of the satellite facing the earth. Magnetic torquing against the earth's magnetic field eliminates the requirement for expendable propellants which would limit satellite life in orbit.
Directory of Open Access Journals (Sweden)
Milutin G. Jovanović
2006-12-01
Full Text Available The brushless doubly-fed machine (BDFM allows the use of a partially rated inverter and represents an attractive cost-effective candidate for variable speed applications with limited speed ranges. In its induction machine form (BDFIM, the BDFM has significant rotor losses and poor efficiency due to the cage rotor design which makes the machine dynamic models heavily parameter dependent and the resulting controller configuration complicated and difficult to implement. A reluctance version of the BDFM, the brushless doubly-fed reluctance machine (BDFRM, ideally has no rotor losses, and therefore offers the prospect for higher efficiency and simpler control compared to the BDFIM. A detailed study of this interesting and emerging machine is very important to gain a thorough understanding of its unusual operation, control aspects and compromises between optimal performance and the size of the inverter and the machine. This paper will attempt to address these issues specifically concentrating on developing conditions for various control properties of the machine such as maximum power factor, maximum torque per inverter ampere and minimum copper losses, as well as analysing the associated trade-offs.
Energy Technology Data Exchange (ETDEWEB)
Muenchow, Frank [Federal-Mogul, Bad Camberg (Germany). Geschaeftsbereich Vehicle Safety and Protection; Harvey, Richard; Richards, Michael [Federal-Mogul Corporation, Logansport, IN (United States). Business Unit Vehicle Safety and Protection
2012-03-15
Electrifying components in commercial vehicles can be a challenge. High vibration levels, for instance, amplify carbon brush and commutator erosion in a conventional electric motor. To offer a solution Federal-Mogul has developed the brushless fuel pump. This BLDC pump has successfully passed 10,000 h of operation in B100 fuel. (orig.)
Strong, G.H.; Faught, M.L.
1963-12-24
A device for safety rod counting in a nuclear reactor is described. A Wheatstone bridge circuit is adapted to prevent de-energizing the hopper coils of a ball backup system if safety rods, sufficient in total control effect, properly enter the reactor core to effect shut down. A plurality of resistances form one arm of the bridge, each resistance being associated with a particular safety rod and weighted in value according to the control effect of the particular safety rod. Switching means are used to switch each of the resistances in and out of the bridge circuit responsive to the presence of a particular safety rod in its effective position in the reactor core and responsive to the attainment of a predetermined velocity by a particular safety rod enroute to its effective position. The bridge is unbalanced in one direction during normal reactor operation prior to the generation of a scram signal and the switching means and resistances are adapted to unbalance the bridge in the opposite direction if the safety rods produce a predetermined amount of control effect in response to the scram signal. The bridge unbalance reversal is then utilized to prevent the actuation of the ball backup system, or, conversely, a failure of the safety rods to produce the predetermined effect produces no unbalance reversal and the ball backup system is actuated. (AEC)
DEFF Research Database (Denmark)
2010-01-01
signal. The control unit comprises a first signal processing unit, a second signal processing unit, and a combiner unit. The first signal processing unit has an output and is supplied with a first carrier signal and an input signal. The second signal processing unit has an output and is supplied...... with a second carrier signal and the input signal. The combiner unit is connected to the first and second signal processing units combining the outputs of the first and the second signal processing units to form a signal representative of the control signal......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...
Directory of Open Access Journals (Sweden)
K.M. Vasyliv
2013-04-01
Full Text Available By means of a mathematical experiment, electromagnetic and electromechanical processes in an independent electric power supply system based on an asynchronized generator with a three-phase modulated exciter are investigated. The processes are analyzed to specify the working capacity of the power supply system during its operation to an induction motors site. Regularities of the electromagnetic and electromechanical processes behavior versus load intensity and the switch control system parameters are identified.
Directory of Open Access Journals (Sweden)
K.M. Vasyliv
2013-02-01
Full Text Available By means of mathematical experiment, the author investigates electromagnetic and electromechanical processes in an independent electric power supply system based on an asynchronized generator with a three-phase modulated exciter. The processes are analyzed to specify the working capacity of the power supply system during its operation under active-inductive loading. Regularities of the electromagnetic and electromechanical processes behavior versus load intensity and the modulator scheme are identified.
Saxena, Anand
The focus of this research was to demonstrate a four blade rotor trim in forward flight using integrated trailing edge flaps instead of using a swashplate controls. A compact brushless DC motor was evaluated as an on-blade actuator, with the possibility of achieving large trailing edge flap amplitudes. A control strategy to actuate the trailing edge flap at desired frequency and amplitude was developed and large trailing edge flap amplitudes from the motor (instead of rotational motion) were obtained. Once the actuator was tested on the bench-top, a lightweight mechanism was designed to incorporate the motor in the blade and actuate the trailing edge flaps. A six feet diameter, four bladed composite rotor with motor-flap system integrated into the NACA 0012 airfoil section was fabricated. Systematic testing was carried out for a range of load conditions, first in the vacuum chamber followed by hover tests. Large trailing edge flap deflections were observed during the hover testing, and a peak to peak trailing edge flap amplitude of 18 degree was achieved at 2000 rotor RPM with hover tip Mach number of 0.628. A closed loop controller was designed to demonstrate trailing edge flap mean position and the peak to peak amplitude control. Further, a soft pitch link was designed and fabricated, to replace the stiff pitch link and thereby reduce the torsional stiffness of the blade to 2/rev. This soft pitch link allowed for blade root pitch motion in response to the trailing edge flap inputs. Blade pitch response due to both steady as well as sinusoidal flap deflections were demonstrated. Finally, tests were performed in Glenn L. Martin wind tunnel using a model rotor rig to assess the performance of motor-flap system in forward flight. A swashplateless trim using brushless DC motor actuated trailing edge flaps was achieved for a rotor operating at 1200 RPM and an advance ratio of 0.28. Also, preliminary exploration was carried out to test the scalability of the motor
Analog circuit design designing dynamic circuit response
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.
Directory of Open Access Journals (Sweden)
Takeuchi, Asia
2011-02-01
Full Text Available Excited (or agitated delirium is characterized by agitation, aggression, acute distress and sudden death, often in the pre-hospital care setting. It is typically associated with the use of drugs that alter dopamine processing, hyperthermia, and, most notably, sometimes with death of the affected person in the custody of law enforcement. Subjects typically die from cardiopulmonary arrest, although the cause is debated. Unfortunately an adequate treatment plan has yet to be established, in part due to the fact that most patients die before hospital arrival. While there is still much to be discovered about the pathophysiology and treatment, it is hoped that this extensive review will provide both police and medical personnel with the information necessary to recognize and respond appropriately to excited delirium. [West J Emerg Med. 2011;12(1:77-83.
Speed Digital Control of Brushless DC Motor Using dsPIC Controller
Directory of Open Access Journals (Sweden)
Gheorghe Băluţă
2014-09-01
Full Text Available This paper presents the digital control of the Brushless DC motor (BLDCM speed. The dsPICDEM MC1 development system (with the dsPIC30F6010A microcontroller and the dsPICDEM MC1L power module, manufactured by Microchip Company, were used. The control program was developed in C programming language. The graphical user interface was realized in LabVIEW 8.6 graphical programming language. For speed control, a digital controller PI type was implemented. Due to digital controller well chosen and well tuned, the system response at speed step variation is very good. Therewith, the experimental results obtained also show a good compensation of disturbance which does not happen in open-loop control.
A flux-mnemonic permanent magnet brushless machine for wind power generation
Yu, Chuang; Chau, K. T.; Jiang, J. Z.
2009-04-01
In this paper, the concept of flux mnemonics is newly extended to the wind power generator. By incorporating a small magnetizing winding into an outer-rotor doubly salient AlNiCo permanent magnet (PM) machine, a new flux-mnemonic PM brushless wind power generator is proposed and implemented. This generator can offer effective and efficient air-gap flux control. First, the characteristics of the proposed generator are analyzed by using the finite element method. Second, the closed-loop flux control is devised to achieve a constant generated voltage under time-varying wind speeds. Finally, the experimental results are given to verify the validity of the proposed generator and control system.
Bat algorithm optimized fuzzy PD based speed controller for brushless direct current motor
Directory of Open Access Journals (Sweden)
K. Premkumar
2016-06-01
Full Text Available In this paper, design of fuzzy proportional derivative controller and fuzzy proportional derivative integral controller for speed control of brushless direct current drive has been presented. Optimization of the above controllers design is carried out using nature inspired optimization algorithms such as particle swarm, cuckoo search, and bat algorithms. Time domain specifications such as overshoot, undershoot, settling time, recovery time, and steady state error and performance indices such as root mean squared error, integral of absolute error, integral of time multiplied absolute error and integral of squared error are measured and compared for the above controllers under different operating conditions such as varying set speed and load disturbance conditions. The precise investigation through simulation is performed using simulink toolbox. From the simulation test results, it is evident that bat optimized fuzzy proportional derivative controller has superior performance than the other controllers considered. Experimental test results have also been taken and analyzed for the optimal controller identified through simulation.
Position and Speed Control of Brushless DC Motors Using Sensorless Techniques and Application Trends
Directory of Open Access Journals (Sweden)
Jaime Gómez-Gil
2010-07-01
Full Text Available This paper provides a technical review of position and speed sensorless methods for controlling Brushless Direct Current (BLDC motor drives, including the background analysis using sensors, limitations and advances. The performance and reliability of BLDC motor drivers have been improved because the conventional control and sensing techniques have been improved through sensorless technology. Then, in this paper sensorless advances are reviewed and recent developments in this area are introduced with their inherent advantages and drawbacks, including the analysis of practical implementation issues and applications. The study includes a deep overview of state-of-the-art back-EMF sensing methods, which includes Terminal Voltage Sensing, Third Harmonic Voltage Integration, Terminal Current Sensing, Back-EMF Integration and PWM strategies. Also, the most relevant techniques based on estimation and models are briefly analysed, such as Sliding-mode Observer, Extended Kalman Filter, Model Reference Adaptive System, Adaptive observers (Full-order and Pseudoreduced-order and Artificial Neural Networks.
Gamazo-Real, José Carlos; Vázquez-Sánchez, Ernesto; Gómez-Gil, Jaime
2010-01-01
This paper provides a technical review of position and speed sensorless methods for controlling Brushless Direct Current (BLDC) motor drives, including the background analysis using sensors, limitations and advances. The performance and reliability of BLDC motor drivers have been improved because the conventional control and sensing techniques have been improved through sensorless technology. Then, in this paper sensorless advances are reviewed and recent developments in this area are introduced with their inherent advantages and drawbacks, including the analysis of practical implementation issues and applications. The study includes a deep overview of state-of-the-art back-EMF sensing methods, which includes Terminal Voltage Sensing, Third Harmonic Voltage Integration, Terminal Current Sensing, Back-EMF Integration and PWM strategies. Also, the most relevant techniques based on estimation and models are briefly analysed, such as Sliding-mode Observer, Extended Kalman Filter, Model Reference Adaptive System, Adaptive observers (Full-order and Pseudoreduced-order) and Artificial Neural Networks.
Pohlmann, André; Hameyer, Kay
2012-01-01
Ventricular Assist Devices (VADs) are mechanical blood pumps that support the human heart in order to maintain a sufficient perfusion of the human body and its organs. During VAD operation blood damage caused by hemolysis, thrombogenecity and denaturation has to be avoided. One key parameter causing the blood's denaturation is its temperature which must not exceed 42 °C. As a temperature rise can be directly linked to the losses occuring in the drive system, this paper introduces an efficiency prediction chain for Brushless DC (BLDC) drives which are applied in various VAD systems. The presented chain is applied to various core materials and operation ranges, providing a general overview on the loss dependencies.
Genetic algorithm based design optimization of a permanent magnet brushless dc motor
Upadhyay, P. R.; Rajagopal, K. R.
2005-05-01
Genetic algorithm (GA) based design optimization of a permanent magnet brushless dc motor is presented in this paper. A 70 W, 350 rpm, ceiling fan motor with radial-filed configuration is designed by considering the efficiency as the objective function. Temperature-rise and motor weight are the constraints and the slot electric loading, magnet-fraction, slot-fraction, airgap, and airgap flux density are the design variables. The efficiency and the phase-inductance of the motor designed using the developed CAD program are improved by using the GA based optimization technique; from 84.75% and 5.55 mH to 86.06% and 2.4 mH, respectively.
Torque ripple reduction of brushless DC motor based on adaptive input-output feedback linearization.
Shirvani Boroujeni, M; Markadeh, G R Arab; Soltani, J
2017-09-01
Torque ripple reduction of Brushless DC Motors (BLDCs) is an interesting subject in variable speed AC drives. In this paper at first, a mathematical expression for torque ripple harmonics is obtained. Then for a non-ideal BLDC motor with known harmonic contents of back-EMF, calculation of desired reference current amplitudes, which are required to eliminate some selected harmonics of torque ripple, are reviewed. In order to inject the reference harmonic currents to the motor windings, an Adaptive Input-Output Feedback Linearization (AIOFBL) control is proposed, which generates the reference voltages for three phases voltage source inverter in stationary reference frame. Experimental results are presented to show the capability and validity of the proposed control method and are compared with the vector control in Multi-Reference Frame (MRF) and Pseudo-Vector Control (P-VC) method results. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
Research of influence of open-winding faults on properties of brushless permanent magnets motor
Bogusz, Piotr; Korkosz, Mariusz; Powrózek, Adam; Prokop, Jan; Wygonik, Piotr
2017-12-01
The paper presents an analysis of influence of selected fault states on properties of brushless DC motor with permanent magnets. The subject of study was a BLDC motor designed by the authors for unmanned aerial vehicle hybrid drive. Four parallel branches per each phase were provided in the discussed 3-phase motor. After open-winding fault in single or few parallel branches, a further operation of the motor can be continued. Waveforms of currents, voltages and electromagnetic torque were determined in discussed fault states based on the developed mathematical and simulation models. Laboratory test results concerning an influence of open-windings faults in parallel branches on properties of BLDC motor were presented.
Optimization of brushless direct current motor design using an intelligent technique.
Shabanian, Alireza; Tousiwas, Armin Amini Poustchi; Pourmandi, Massoud; Khormali, Aminollah; Ataei, Abdolhay
2015-07-01
This paper presents a method for the optimal design of a slotless permanent magnet brushless DC (BLDC) motor with surface mounted magnets using an improved bee algorithm (IBA). The characteristics of the motor are expressed as functions of motor geometries. The objective function is a combination of losses, volume and cost to be minimized simultaneously. This method is based on the capability of swarm-based algorithms in finding the optimal solution. One sample case is used to illustrate the performance of the design approach and optimization technique. The IBA has a better performance and speed of convergence compared with bee algorithm (BA). Simulation results show that the proposed method has a very high/efficient performance. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.
Numerical and Experimental Investigation of Heat Flow in Permanent Magnet Brushless DC Hub Motor
DEFF Research Database (Denmark)
Fasil, Muhammed; Plesner, Daniel; Walther, Jens Honore
2014-01-01
This paper investigates the heat dissipation in the hub motor of an electric two-wheeler using lumped parameter (LP), finite element (FE) and computational fluid dynamic (CFD) models. The motor uses external rotor permanent magnet brushless DC topology and nearly all of its losses are generated...... in the stator. The hub motor construction restricts the available conductive paths for heat dissipation from the stator to the ambient only through the shaft. In contrast to an internal rotor structure, where the stator winding losses are diffused via conduction, here convection plays a major role in loss...... dissipation. Therefore, a LP thermal model with improved convection modelling has been proposed to calculate the temperature of the components inside the hub motor. The developed model is validated with the FE thermal model and the test data. In addition, CFD tools has been used to accurately model...
Demerdash, N. A.; Nehl, T. W.
1979-01-01
A comprehensive digital model for the analysis of the dynamic-instantaneous performance of a power conditioner fed samarium-cobalt permanent magnet brushless DC motor is presented. The particular power conditioner-machine system at hand, for which this model was developed, is a component of an actual prototype electromechanical actuator built for NASA-JSC as a possible alternative to hydraulic actuators as part of feasibility studies for the shuttle orbiter applications. Excellent correlation between digital simulated and experimentally obtained performance data was achieved for this specific prototype. This is reported on in this paper. Details of one component of the model, its applications and the corresponding results are given in this paper.
Analog circuit design designing waveform processing circuits
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.
Directory of Open Access Journals (Sweden)
Yoon-Ho Kim
2016-01-01
Full Text Available The equivalent test circuit that can deliver both short-circuit current and recovery voltage is used to verify the performance of high-voltage circuit breakers. Most of the parameters in this circuit can be obtained by using a simple calculation or a simulation program. The ratings of the circuit breaker include rated short-circuit breaking current, rated short-circuit making current, rated operating sequence of the circuit breaker and rated short-time current. Among these ratings, the short-circuit making capacity of the circuit breaker is expressed in peak value and not in RMS value similar to breaking capacity. A series resistor or super-excitation is used to control the peak value of the short-circuit current in the equivalent test circuit. When using a series resistor, a higher rating of circuit breakers leads to a higher thermal capacity, thereby requiring additional space. Therefore, an effective, optimal design of the series resistor is essential. This paper proposes a method for reducing thermal capacity and selecting the optimal resistance to limit the making current by controlling the DC time constant of the test circuit.
Directory of Open Access Journals (Sweden)
Roni Permana Saputra
2012-03-01
Full Text Available This paper discusses the design of control system for brushless DC motor using microcontroller ATMega 16 that will be applied to an independent 4-wheel drive Mobile Robot LIPI version 2 (REV-11. The control system consists of two parts which are brushless DC motor control module and supervisory control module that coordinates the desired command to the motor control module. To control the REV-11 platform, supervisory control transmit the reference data of speed and direction of motor to control the speed and direction of each actuator on the platform REV-11. From the test results it is concluded that the designed control system work properly to coordinate and control the speed and direction of motion of the actuator motor REV-11 platform.
Moazen, Maryam; Kazemzadeh, Rasool; Azizian, Mohammad-Reza
2016-01-01
In this paper, a predictive direct power control (PDPC) method for the brushless doubly fed reluctance generator (BDFRG) is proposed. Firstly, the BDFRG active and reactive power equations are derived and then the active and reactive power variations have been predicted within a fixed sampling period. The predicted power variations are used to calculate the required voltage of the secondary winding so that the power errors at the end of the following sampling period are eliminated. Switching ...
Garcia-Escartin, Juan Carlos; Chamorro-Posada, Pedro
2011-01-01
Quantum algorithms and protocols are often presented as quantum circuits for a better understanding. We give a list of equivalence rules which can help in the analysis and design of quantum circuits. As example applications we study quantum teleportation and dense coding protocols in terms of a simple XOR swapping circuit and give an intuitive picture of a basic gate teleportation circuit.
Hysteresis in a quantized superfluid `atomtronic' circuit
Eckel, Stephen; Lee, Jeffrey G.; Jendrzejewski, Fred; Murray, Noel; Clark, Charles W.; Lobb, Christopher J.; Phillips, William D.; Edwards, Mark; Campbell, Gretchen K.
2014-02-01
Atomtronics is an emerging interdisciplinary field that seeks to develop new functional methods by creating devices and circuits where ultracold atoms, often superfluids, have a role analogous to that of electrons in electronics. Hysteresis is widely used in electronic circuits--it is routinely observed in superconducting circuits and is essential in radio-frequency superconducting quantum interference devices. Furthermore, it is as fundamental to superfluidity (and superconductivity) as quantized persistent currents, critical velocity and Josephson effects. Nevertheless, despite multiple theoretical predictions, hysteresis has not been previously observed in any superfluid, atomic-gas Bose-Einstein condensate. Here we directly detect hysteresis between quantized circulation states in an atomtronic circuit formed from a ring of superfluid Bose-Einstein condensate obstructed by a rotating weak link (a region of low atomic density). This contrasts with previous experiments on superfluid liquid helium where hysteresis was observed directly in systems in which the quantization of flow could not be observed, and indirectly in systems that showed quantized flow. Our techniques allow us to tune the size of the hysteresis loop and to consider the fundamental excitations that accompany hysteresis. The results suggest that the relevant excitations involved in hysteresis are vortices, and indicate that dissipation has an important role in the dynamics. Controlled hysteresis in atomtronic circuits may prove to be a crucial feature for the development of practical devices, just as it has in electronic circuits such as memories, digital noise filters (for example Schmitt triggers) and magnetometers (for example superconducting quantum interference devices).
Directory of Open Access Journals (Sweden)
Reza Ilka
2012-04-01
Full Text Available ABSTRACT: This paper develops a mathematical relationship for the purpose of designing and selecting the optimum dimensions of a brushless permanent magnet motor. The design is optimised by the use of artificial bee colony algorithm with the goal of maximizing the power density and efficiency of the motor. The required dimensions of the brushless motor are calculated based on the optimum power density and efficiency requirements. Finally, the predicted results of the optimisation are validated using a 2-D numerical program based on finite element analysis.ABSTRAK: Kajian ini mencadangkan persamaan yang menghubungkan rekabentuk dan dimensi magnet motor kekal tanpa berus. Rekabentuk optima berdasarkan algorisma koloni lebah tiruan dengan tujuan meningkatkan ketumpatan kuasa dan keberkesanan dibentangkan dalam kajian ini. Dimensi magnet motor kekal tanpa berus dihitung dengan ketumpatan kuasa optima dan keberkesanan. Akhirnya, keputusan telah disahkan dengan menggunakan program berangka 2-D berdasarkan analisis elemen finit.KEYWORDS: brushless; permanent magnet motor; power density; artificial bee colony; algorithm; finite element analysis
Bera, Debajyoti; Fenner, Stephen; Green, Frederic; Homer, Steve
2008-01-01
We define and construct efficient depth-universal and almost-size-universal quantum circuits. Such circuits can be viewed as general-purpose simulators for central classes of quantum circuits and can be used to capture the computational power of the circuit class being simulated. For depth we construct universal circuits whose depth is the same order as the circuits being simulated. For size, there is a log factor blow-up in the universal circuits constructed here. We prove that this construc...
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
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
Design and Performance Test of Axial Halbach Brushless DC Motor with Power Density 1.5 Kw/Kg
Directory of Open Access Journals (Sweden)
Kevin Dwi Prasetio
2017-01-01
Full Text Available Progress of technology on electric vehicle component sector is one reason the emergence of electric vehicles at the moment. Starting from battery which has a great current density up to the automatic control systems on electric vehicles. But there are still some shortcomings of this electric vehicle components, one of which is the low value of power density of existing electric motor in the market today.On vehicles such as electric cars when Race Car Contest, energy saving problems about power density of the driving motor is very vital. This is because the total weight of the vehicle has a huge influence on the vehicle efficiency is against it. The issue is one of the reasons of the research task. In this final task is done making the design, simulation, and architecture of the Axial Halbach Brushless DC Motor. Use of system configuration on the halbach magnet to avoid the use of iron as a material cantilever rotor. By changing the material of the cantilever rotor with lighter materials such as aluminum or even carbon fibre, the value of power density electric motors can be increased. Then using the litz wire on coil stator to reduce loss-power loss due to the barriers on the coil. Coreless stator on the system and to avoid the phenomenon of cogging at the time due to low rpm style attraction magnet with iron in the core material. While the creation process begins by determining the specifications of the Axial Halbach Brushless DC motors. Then go into the design phase of the mechanical and electrical design. Who then conducted simulations to help determine other parameters such as air gap, slot turn, and magnetic orientation. The process of making a component of stator and rotor after the simulation is completed. After all the components of the rotor and stator on assembly, mounting the hall sensor is carried out to the right to position obtained by reading the signals. After the motor can spin with good motor performance, testing can be done
The circuit designer's companion
Williams, Tim
1991-01-01
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
Electronic devices and circuits
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
Intuitive analog circuit design
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
Loss of excitation of synchronous generator
Krištof, Vladimír; Mešter, Marián
2017-01-01
This paper presents results of study of loss-of-excitation phenomena simulations. Loss of excitation is a very common fault in synchronous machine operating and can be caused by short circuit of the field winding, unexpected field breaker open or loss-of-excitation relay mal-operation. According to the statistic [1], the generator failure due to loss-of-excitation accounts for 69% of all generator failures. There has been concern over possible incorrect operation of the relay when operating the generator in the under-excited region, during stable transient swings and during major system disturbances. This article can serve as inputs for system operators in preparation of operation area or protection relaying area.
Gwaltney, D. A.
2002-01-01
A FY 2001 Center Director's Discretionary Fund task to develop a test platform for the development, implementation. and evaluation of adaptive and other advanced control techniques for brushless DC (BLDC) motor-driven mechanisms is described. Important applications for BLDC motor-driven mechanisms are the translation of specimens in microgravity experiments and electromechanical actuation of nozzle and fuel valves in propulsion systems. Motor-driven aerocontrol surfaces are also being utilized in developmental X vehicles. The experimental test platform employs a linear translation stage that is mounted vertically and driven by a BLDC motor. Control approaches are implemented on a digital signal processor-based controller for real-time, closed-loop control of the stage carriage position. The goal of the effort is to explore the application of advanced control approaches that can enhance the performance of a motor-driven actuator over the performance obtained using linear control approaches with fixed gains. Adaptive controllers utilizing an exact model knowledge controller and a self-tuning controller are implemented and the control system performance is illustrated through the presentation of experimental results.
Directory of Open Access Journals (Sweden)
SANJEEV SINGH
2010-12-01
Full Text Available Permanent magnet brushless DC motor (PMBLDCM drives are being employed in many variable speed applications due to their high efficiency, silent operation, compact size, high reliability, ease of control, and low maintenance requirements. These drives have power quality problems and poor power factor at input AC mains as they are mostly fed through diode bridge rectifier based voltage source inverters. To overcome such problems a single-phase single-switch power factor correction AC-DC converter topology based on a Cuk converter is proposed to feed voltage source inverters based PMBLDCM. It focuses on the analysis, design and performance evaluation of the proposed PFC converter topology for a 1.5 kW, 1500 rpm, 400 V PMBLDCM drive used for an air-conditioning system. The proposed PFC converter topology is modelled and its performance is simulated in Matlab-Simulink environment and results show an improved power quality and good power factor in wide speed range of the drive.
On Stability of Open-Loop Operation without Rotor Information for Brushless DC Motors
Directory of Open Access Journals (Sweden)
Zhong Wu
2014-01-01
Full Text Available Open-loop operation mode is often used to control the Brushless DC Motors (BLDCMs without rotor position sensors when the back electromotive force (EMF is too weak due to the very low rotor velocity. The rotor position information is not necessary in this mode and the stator windings are supplied with voltages under a certain ratio of the amplitude to the frequency. However, the rotor synchronization will be destroyed once if the commutation instant is inappropriate. In order to improve the reliability of the open-loop operation mode, a dynamic equation is established to represent the synchronization error between the rotor and the stator. Thereafter, the stability of the open-loop control mode is analyzed by using Lyapunov indirect method. Theoretical analysis indicates that the open-loop control mode is asymptotically stable only when the commutation instant of the stator current lags behind the ideal one suitably. Finally, theoretical analysis is verified through the experimental results of a certain BLDCM.
A new technique to control brushless motor for blood pump application.
Fonseca, Jeison; Andrade, Aron; Nicolosi, Denys E C; Biscegli, José F; Legendre, Daniel; Bock, Eduardo; Lucchi, Júlio César
2008-04-01
This article presents a back-electromotive force (BEMF)-based technique of detection for sensorless brushless direct current motor (BLDCM) drivers. The BLDCM has been chosen as the energy converter in rotary or pulsatile blood pumps that use electrical motors for pumping. However, in order to operate properly, the BLDCM driver needs to know the shaft position. Usually, that information is obtained through a set of Hall sensors assembled close to the rotor and connected to the electronic controller by wires. Sometimes, a large distance between the motor and controller makes the system susceptible to interference on the sensor signal because of winding current switching. Thus, the goal of the sensorless technique presented in this study is to avoid this problem. First, the operation of BLDCM was evaluated on the electronic simulator PSpice. Then, a BEMF detector circuitry was assembled in our laboratories. For the tests, a sensor-dependent system was assembled where the direct comparison between the Hall sensors signals and the detected signals was performed. The obtained results showed that the output sensorless detector signals are very similar to the Hall signals at speeds of more than 2500 rpm. Therefore, the sensorless technique is recommended as a responsible or redundant system to be used in rotary blood pumps.
Brushless DC motor control system responsive to control signals generated by a computer or the like
Packard, Douglas T. (Inventor); Schmitt, Donald E. (Inventor)
1987-01-01
A control system for a brushless DC motor responsive to digital control signals is disclosed. The motor includes a multiphase wound stator and a permanent magnet rotor. The rotor is arranged so that each phase winding, when energized from a DC source, will drive the rotor through a predetermined angular position or step. A commutation signal generator responsive to the shaft position provides a commutation signal for each winding. A programmable control signal generator such as a computer or microprocessor produces individual digital control signals for each phase winding. The control signals and commutation signals associated with each winding are applied to an AND gate for that phase winding. Each gate controls a switch connected in series with the associated phase winding and the DC source so that each phase winding is energized only when the commutation signal and the control signal associated with that phase winding are present. The motor shaft may be advanced one step at a time to a desired position by applying a predetermined number of control signals in the proper sequence to the AND gates and the torque generated by the motor may be regulated by applying a separate control signal to each AND gate which is pulse width modulated to control the total time that each switch connects its associated winding to the DC source during each commutation period.
Brushless DC motor control system responsive to control signals generated by a computer or the like
Packard, D. T.
1985-04-01
A control system for a brushless DC motor responsive to digital control signals is disclosed. The motor includes a multiphase wound stator and a permanent magnet rotor. The motor is arranged so that each phase winding, when energized from a DC source, will drive the rotor through a predetermined angular position or step. A commutation signal generator responsive to the shaft position provides a commutation signal for each winding. A programmable control signal generator such as a computer or microprocessor produces individual digital control signals for each phase winding. The control signals and commutation signals associated with each winding are applied to an AND gate for that phase winding. Each gate controls a switch connected in series with the associated phase winding and the DC source so that each phase winding is energized only when the commutation signal and the control signal associated with that phase winding are present. The motor shaft may be advanced one step at a time to a desired position by applying a predetermined number of control signals in the proper sequence to the AND gates and the torque generated by the motor be regulated by applying a separate control signal and each AND gate which is pulse width modulated to control the total time that each switch connects its associated winding to the DC source during each commutation period.
Sensor-less pseudo-sinusoidal drive for a permanent-magnet brushless ac motor
Liu, Li-Hsiang; Chern, Tzuen-Lih; Pan, Ping-Lung; Huang, Tsung-Mou; Tsay, Der-Min; Kuang, Jao-Hwa
2012-04-01
The precise rotor-position information is required for a permanent-magnet brushless ac motor (BLACM) drive. In the conventional sinusoidal drive method, either an encoder or a resolver is usually employed. For position sensor-less vector control schemes, the rotor flux estimation and torque components are obtained by complicated coordinate transformations. These computational intensive methods are susceptible to current distortions and parameter variations. To simplify the method complexity, this work presents a sensor-less pseudo-sinusoidal drive scheme with speed control for a three-phase BLACM. Based on the sinusoidal drive scheme, a floating period of each phase current is inserted for back electromotive force detection. The zero-crossing point is determined directly by the proposed scheme, and the rotor magnetic position and rotor speed can be estimated simultaneously. Several experiments for various active angle periods are undertaken. Furthermore, a current feedback control is included to minimize and compensate the torque fluctuation. The experimental results show that the proposed method has a competitive performance compared with the conventional drive manners for BLACM. The proposed scheme is straightforward, bringing the benefits of sensor-less drive and negating the need for coordinate transformations in the operating process.
Speed Control Analysis of Brushless DC Motor Based on Maximum Amplitude DC Current Feedback
Directory of Open Access Journals (Sweden)
Hassan M.A.A.
2014-07-01
Full Text Available This paper describes an approach to develop accurate and simple current controlled modulation technique for brushless DC (BLDC motor drive. The approach is applied to control phase current based on generation of quasi-square wave current by using only one current controller for the three phases. Unlike the vector control method which is complicated to be implemented, this simple current modulation technique presents advantages such as phase currents are kept in balance and the current is controlled through only one dc signal which represent maximum amplitude value of trapezoidal current (Imax. This technique is performed with Proportional Integral (PI control algorithm and triangular carrier comparison method to generate Pulse Width Modulation (PWM signal. In addition, the PI speed controller is incorporated with the current controller to perform desirable speed operation of non-overshoot response. The performance and functionality of the BLDC motor driver are verified via simulation by using MATLAB/SIMULINK. The simulation results show the developed control system performs desirable speed operation of non-overshoot and good current waveforms.
Optimization Design and Performance Analysis of a PM Brushless Rotor Claw Pole Motor with FEM
Directory of Open Access Journals (Sweden)
Zhenyang Zhang
2016-07-01
Full Text Available A new type of permanent magnet (PM brushless claw pole motor (CPM with soft magnetic composite (SMC core is designed and analyzed in this paper. The PMs are mounted on the claw pole surface, and the three-phase stator windings are fed by variable-frequency three-phase AC currents. The advantages of the proposed CPM are that the slip rings on the rotor are cast off and it can achieve the efficiency improvement and higher power density. The effects of the claw-pole structure parameters, the air-gap length, and the PM thinner parameter of the proposed CPM on the output torque are investigated by using three-dimensional time-stepping finite element method (3D TS-FEM. The optimal rotor structure of the proposed CPM is obtained by using the response surface methodology (RSM and the particle swarm optimization (PSO method and the comparison of full-load performances of the proposed CPM with different material cores (SMC and silicon steel is analyzed.
Directory of Open Access Journals (Sweden)
GHOLAMIAN, A. S.
2009-06-01
Full Text Available In this paper, a magnet shape optimization method for reduction of cogging torque and torque ripple in Permanent Magnet (PM brushless DC motors is presented by using the reduced basis technique coupled by finite element and design of experiments methods. The primary objective of the method is to reduce the enormous number of design variables required to define the magnet shape. The reduced basis technique is a weighted combination of several basis shapes. The aim of the method is to find the best combination using the weights for each shape as the design variables. A multi-level design process is developed to find suitable basis shapes or trial shapes at each level that can be used in the reduced basis technique. Each level is treated as a separated optimization problem until the required objective is achieved. The experimental design of Taguchi method is used to build the approximation model and to perform optimization. This method is demonstrated on the magnet shape optimization of a 6-poles/18-slots PM BLDC motor.
Speed response of brushless DC motor using fuzzy PID controller under varying load condition
Directory of Open Access Journals (Sweden)
Akash Varshney
2017-09-01
Full Text Available The increasing trend towards usage of precisely controlled, high torque, efficient and low noise motors for dedicated applications has attracted the attention of researcher in Brushless DC (BLDC motors. BLDC motors can act as an acceptable alternative to the conventional motors like Induction Motors, Switched Reluctance Motors etc. This paper presents a detailed study on the performance of a BLDC motor supplying different types of loads, and at the same time, deploying different control techniques. An advance Fuzzy PID controller is compared with the commonly used PID controller. The load variations considered are of the most common types, generally encountered in practice. A comparison has been carried out in this paper by observing the dynamic speed response of motor at the time of application as well as at the time of removal of the load. The BLDC motors suffer from a major drawback of having jerky behaviour at the time of load removal. The study reveals that irrespective of the type of controller used, the gradual load variation produces better results as against sudden load variations. It is further observed that in addition to other dynamic features, the jerks produced at the time of load removal also get improved to a large extent with Fuzzy PID controller.The speed torque characteristics unraveled the fact that the jerks are minimum at the time of gradual load removal with Fuzzy PID controller in place. An attempt has been made to define these jerks by ‘Perturbation Window’.
Research on an Axial Magnetic-Field-Modulated Brushless Double Rotor Machine
Directory of Open Access Journals (Sweden)
Bin Yu
2013-09-01
Full Text Available Double rotor machine, an electronic continuously variable transmission, has great potential in application of hybrid electric vehicles (HEVs, wind power and marine propulsion. In this paper, an axial magnetic-field-modulated brushless double rotor machine (MFM-BDRM, which can realize the speed decoupling between the shaft of the modulating ring rotor and that of the permanent magnet rotor is proposed. Without brushes and slip rings, the axial MFM-BDRM offers significant advantages such as excellent reliability and high efficiency. Since the number of pole pairs of the stator is not equal to that of the permanent magnet rotor, which differs from the traditional permanent magnet synchronous machine, the operating principle of the MFM-BDRM is deduced. The relations of corresponding speed and toque transmission are analytically discussed. The cogging toque characteristics, especially the order of the cogging torque are mathematically formulated. Matching principle of the number of pole pairs of the stator, that of the permanent magnet rotor and the number of ferromagnetic pole pieces is inferred since it affects MFM-BDRM’s performance greatly, especially in the respect of the cogging torque and electromagnetic torque ripple. The above analyses are assessed with the three-dimensional (3D finite-element method (FEM.
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
Wing, Omar
2008-01-01
Starting with the basic principles of circuits, this book derives their analytic properties in both the time and frequency domains. It develops an algorithmic method to design common and uncommon types of circuits, such as prototype filters, lumped delay lines, constant phase difference circuits, and delay equalizers.
Louwsma, S.M.; 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
Louwsma, S.M.; 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
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.
DEFF Research Database (Denmark)
Hansen, Kristoffer Arnsfelt; Podolskii, Vladimir V.
2010-01-01
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...
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...
Bergstra, J.A.; Ponse, A.
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
Energy Technology Data Exchange (ETDEWEB)
Luo, Shaohua, E-mail: hua66com@163.com [The Jiangsu Key Laboratory of Advanced Manufacturing Technology, Huaiyin Institute of Technology, Huai’an 223003 (China); School of Automation, Chongqing University, Chongqing 400044 (China); Hou, Zhiwei; Chen, Zhong [The Jiangsu Key Laboratory of Advanced Manufacturing Technology, Huaiyin Institute of Technology, Huai’an 223003 (China)
2015-12-15
In this paper, chaos control is proposed for the output- constrained system with uncertain control gain and time delay and is applied to the brushless DC motor. Using the dynamic surface technology, the controller overcomes the repetitive differentiation of backstepping and boundedness hypothesis of pre-determined control gain by incorporating radial basis function neural network and adaptive technology. The tangent barrier Lyapunov function is employed for time-delay chaotic system to prevent constraint violation. It is proved that the proposed control approach can guarantee asymptotically stable in the sense of uniformly ultimate boundedness without constraint violation. Finally, the effectiveness of the proposed approach is demonstrated on the brushless DC motor example.
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...
Directory of Open Access Journals (Sweden)
Wang Jixiang
2017-01-01
Full Text Available Precise electro-magnetic parameters are significant in the investigation of characteristic for brushless synchronous starter/generator system, especially the inductance during the starting process.This paper presented an analytical method for inductance calculation, which analysed the influence of stator windings’ parallel structure on inductance calculation and took the skewed slot structure into consideration. Due to the skewed slot structure, applicable two-dimensional coordinate systems were established .This proposed method could save time in calculation according to the simplification to some extent. The results of analytical method were presented and compared with the simulation results. The reason for the differences has been analyzed.
DEFF Research Database (Denmark)
Han, Peng; Cheng, Ming; Chen, Zhe
2016-01-01
This paper presents a dual-electrical-port control scheme of cascaded brushless doubly-fed induction machine (CBDFIM) for EV/HEV applications aiming at achieving doubled constant torque and constant power regions compared to its singly-fed counterpart with the same equivalent pole pair number....... The proposed control method enables the synchronous control of both current inputs of power winding and control winding and as a consequence, not only the control complexity, but also slip frequency and core loss are significantly reduced in comparison with the single-electrical-port control scheme. Computer...
Modeling and control of a novel dual-stator brushless doubly-fed wind power generation system
DEFF Research Database (Denmark)
Cheng, Ming; Wei, Xinchi; Han, Peng
2014-01-01
A novel dual-stator brushless doubly-fed induction generator-based wind power generation system (DSBDFIG-WPGS), with the merits of reduced converter scale, compact structure and high reliability, is proposed in this paper. System topology, operational principle and power flow of the DSBDFIG......-WPGS are analyzed. Based on the modelling of the system, a vector control scheme is proposed to realize decoupled control of the reactive power and the speed. Furthermore, a speed based maximum power point tracking method is adopted in the system. The simulation results demonstrate stable operation of the DSBDFIG...
DEFF Research Database (Denmark)
Zhang, Xiaoxu; Liu, Xiao; Chen, Zhe
2015-01-01
This paper presents a rapid approach to compute the magnetic field distribution in a flux-modulated permanent-magnet brushless motor. Partial differential equations are used to describe the magnet field behavior in terms of magnetic vector potentials. The whole computational domain is divided...... into several regions, i.e., magnet, air-gaps, slot-openings, and slots. The numerical solution could be obtained by applying the boundary constraints on the interfaces between these regions. The accuracy of the proposed analytical model is verified by comparing the no-load magnetic field and armature reaction...... magnetic field with those calculated by finite element method....
Extended Constant Power Speed Range of the Brushless DC Motor Through Dual Mode Inverter Control
Energy Technology Data Exchange (ETDEWEB)
Lawler, J.S.
2000-06-23
The trapezoidal back electromotive force (emf) brushless direct current (dc) motor (BDCM) with surface-mounted magnets has high-power density and efficiency especially when rare-earth magnet materials are used. Traction applications, such as electric vehicles, could benefit significantly from the use of such motors. Unfortunately, a practical means for driving the motor over a constant power speed ratio (CPSR) of 5:1 or more has not yet been developed. A key feature of these motors is that they have low internal inductance. The phase advance method is effective in controlling the motor power over such a speed range, but the current at high speed may be several times greater than that required at the base speed. The increase in current during high-speed operation is due to the low motor inductance and the action of the bypass diodes of the inverter. The use of such a control would require increased current rating of the inverter semiconductors and additional cooling for the inverter, where the conduction losses increase proportionally with current, and especially for the motor, where the losses increase with the square of the current. The high current problems of phase advance can be mitigated by adding series inductance; however, this reduces power density, requires significant increase in supply voltage, and leaves the CPSR performance of the system highly sensitive to variations in the available voltage. A new inverter topology and control scheme has been developed that can drive low-inductance BDCMs over the CPSR that would be required in electric vehicle applications. This new controller is called the dual-mode inverter control (DMIC). It is shown that the BDCM has an infinite CPSR when it is driven by the DMIC.
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
Renovating the excitation circuit of a conventional welding converter
Indian Academy of Sciences (India)
current. For this purpose phase control and PWM control techniques were employed. These two solutions were theoretically and practically examined. 2. A general description of the existing direct current arc welding converter. The old existing converter is composed of a direct current generator, a three-phase induction.
Sabah, Nassir H
2007-01-01
Circuit Variables and Elements Overview Learning Objectives Electric Current Voltage Electric Power and Energy Assigned Positive Directions Active and Passive Circuit Elements Voltage and Current Sources The Resistor The Capacitor The Inductor Concluding Remarks Summary of Main Concepts and Results Learning Outcomes Supplementary Topics on CD Problems and Exercises Basic Circuit Connections and Laws Overview Learning Objectives Circuit Terminology Kirchhoff's Laws Voltage Division and Series Connection of Resistors Current Division and Parallel Connection of Resistors D-Y Transformation Source Equivalence and Transformation Reduced-Voltage Supply Summary of Main Concepts and Results Learning Outcomes Supplementary Topics and Examples on CD Problems and Exercises Basic Analysis of Resistive Circuits Overview Learning Objectives Number of Independent Circuit Equations Node-Voltage Analysis Special Considerations in Node-Voltage Analysis Mesh-Current Analysis Special Conside...
Directory of Open Access Journals (Sweden)
Ping Zheng
2017-05-01
Full Text Available The magnetic-field-modulated brushless double-rotor machine (MFM-BDRM, composed of a stator, a modulating ring rotor, and a PM rotor, is a kind of power-split device for hybrid electric vehicles (HEVs. In this paper, a new MFM-BDRM with sinusoidal-permeance modulating ring named Sinusoidal-Permeance-Modulating-Ring Brushless Double-Rotor Machine (SPMR-BDRM is proposed to solve the problem of poor mechanical strength and large iron loss. The structure and the operating principle of the MFM-BDRM are introduced. The design principle of the sinusoidal-permeance modulating ring is analyzed and derived. The main idea of that is to minimize the harmonic permeance of air gap, thereby the harmonic magnetic fields can be restrained. There are comparisons between a MFM-BDRM with sinusoidal-permeance modulating ring and a same size MFM-BDRM with traditional modulating ring, including magnetic field distributions and electromagnetic performances. Most importantly, the iron losses are compared under six different conditions. The result indicates that the harmonic magnetic fields in the air gap are restrained; the electromagnetic torque and power factor are almost the same with same armature current; the torque ripples of the modulating ring rotor and the PM rotor are reduced; the stator loss is reduced by 13% at least and the PM loss is reduced by 20% at least compared with the same size traditional MFM-BDRM under the same operating conditions.
Zheng, Ping; Liu, Jiaqi; Bai, Jingang; Song, Zhiyi; Liu, Yong
2017-05-01
The magnetic-field-modulated brushless double-rotor machine (MFM-BDRM), composed of a stator, a modulating ring rotor, and a PM rotor, is a kind of power-split device for hybrid electric vehicles (HEVs). In this paper, a new MFM-BDRM with sinusoidal-permeance modulating ring named Sinusoidal-Permeance-Modulating-Ring Brushless Double-Rotor Machine (SPMR-BDRM) is proposed to solve the problem of poor mechanical strength and large iron loss. The structure and the operating principle of the MFM-BDRM are introduced. The design principle of the sinusoidal-permeance modulating ring is analyzed and derived. The main idea of that is to minimize the harmonic permeance of air gap, thereby the harmonic magnetic fields can be restrained. There are comparisons between a MFM-BDRM with sinusoidal-permeance modulating ring and a same size MFM-BDRM with traditional modulating ring, including magnetic field distributions and electromagnetic performances. Most importantly, the iron losses are compared under six different conditions. The result indicates that the harmonic magnetic fields in the air gap are restrained; the electromagnetic torque and power factor are almost the same with same armature current; the torque ripples of the modulating ring rotor and the PM rotor are reduced; the stator loss is reduced by 13% at least and the PM loss is reduced by 20% at least compared with the same size traditional MFM-BDRM under the same operating conditions.
Demerdash, N. A. O.; Nehl, T. W.
1979-01-01
A mathematical model was developed and computerized simulations were obtained for a brushless dc motor. Experimentally obtained oscillograms of the machine phase currents are presented and the corresponding current and voltage waveforms for various modes of operation of the motor are presented and discussed.
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.
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. <
Regenerative feedback resonant circuit
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.
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
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
Nanoscale Microelectronic Circuit Development
2011-06-17
Project 3: Low-Power All-Digital Chip-to-Chip Interface Circuits by Pavan Kumar Hanumolu (OSU) CDADIC Project 4: Nanoscale Clock and Data Recovery...CDADIC Project 3: Low-Power All-Digital Chip-to-Chip Interface Circuits by Pavan Kumar Hanumolu (OSU) CDADIC Project 6: Stochastic and Passive A/D...Area 3: Reconfigurable Mixed-Signal Circuits CDADIC Project 3: Low-Power All-Digital Chip-to-Chip Interface Circuits by Pavan Kumar Hanumolu (OSU
Timergenerator circuits manual
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
Electronic devices and circuits
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
Security electronics circuits manual
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
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
Wiegerink, Remco J.; Seevinck, Evert; de Jager, Wim
1989-01-01
A monolithic offset cancelling circuit to reduce the offset voltage at an integrated audio-amplifier output is described. This offset voltage is detected using a low-pass filter with a very large time constant for which only one small on-chip capacitor is needed. The circuit was realized with a
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...
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…
Analysis of the Torque Ripples in Designing a Disk Type Brushless Direct Current Motor
Directory of Open Access Journals (Sweden)
A. V. Stepanov
2015-01-01
Full Text Available This paper investigates the torque ripples of disk-type low-power brushless direct current motor (BDCM with permanent magnets. In spite of numerous studies on designing of valve engines this issue is understudied as yet. The torque ripples cause noise and vibration and can significantly limit accuracy when used in instrumentation, computer technology.We consider a motor that includes a power unit consisting of a rotor and a stator. There are ferrite elements of sensor on the rotor, and the nonmagnetic disk, bonded to it, contains permanent magnets. The rotor is mounted on a rotating shaft. The stator consists of a steel casing and bonded to it non-magnetic, non-conductive disk with holes. In the disk holes from both sides are mounted armature coils. The armature winding consists of two sections each of which has 6 coils. Each adjacent coil in section has an opposite direction of winding. The coils are arranged circumferentially and are shifted relative to each other; the displacement angle between the coils of one section is equal to 2π/6 (rad. Sections are also shifted relative to each other; the angular shift is π/6 (rad. Sections are connected to the output terminals of the electronic switch. Sections of motor windings have the reverse full-wave power.The paper has investigated the steady operation at four-stroke switching and under constant load (torque. In this case, the electromagnetic torque and rotor speed are periodical functions of the rotor rotation angle. The dependencies of the averaged torque on the rotation speed have been obtained. The spectral distribution of the torque ripples at various rotor speeds of rotation has been calculated. The dependencies of the torque on the speed were studied both at constant speed and taking into account the uneven speed. Based on the research findings of disk type BDCM was computed a level of ripples amounted to 0.8 - 5%, which is quite acceptable for use in a drive. The results are useful for
Allen, Phillip E
1987-01-01
This text presents the principles and techniques for designing analog circuits to be implemented in a CMOS technology. The level is appropriate for seniors and graduate students familiar with basic electronics, including biasing, modeling, circuit analysis, and some familiarity with frequency response. Students learn the methodology of analog integrated circuit design through a hierarchically-oriented approach to the subject that provides thorough background and practical guidance for designing CMOS analog circuits, including modeling, simulation, and testing. The authors' vast industrial experience and knowledge is reflected in the circuits, techniques, and principles presented. They even identify the many common pitfalls that lie in the path of the beginning designer--expert advice from veteran designers. The text mixes the academic and practical viewpoints in a treatment that is neither superficial nor overly detailed, providing the perfect balance.
Approximate circuits for increased reliability
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.
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.
Circuit for Driving Piezoelectric Transducers
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
Troubleshooting analog circuits
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
Circuit analysis with Multisim
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
Optoelectronics circuits manual
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.
Plasmonic Nanoguides and Circuits
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
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
Sigma-1 Receptor and Neuronal Excitability.
Kourrich, Saïd
2017-01-01
The sigma-1 receptor (Sig-1R), via interaction with various proteins, including voltage-gated and ligand-gated ion channels (VGICs and LGICs), is involved in a plethora of neuronal functions. This capability to regulate a variety of ion channel targets endows the Sig-1R with a powerful capability to fine tune neuronal excitability, and thereby the transmission of information within brain circuits. This versatility may also explain why the Sig-1R is associated to numerous diseases at both peripheral and central levels. To date, how the Sig-1R chooses its targets and how the combinations of target modulations alter overall neuronal excitability is one of the challenges in the field of Sig-1R-dependent regulation of neuronal activity. Here, we will describe and discuss the latest findings on Sig-1R-dependent modulation of VGICs and LGICs, and provide hypotheses that may explain the diverse excitability outcomes that have been reported so far.
Directory of Open Access Journals (Sweden)
Mohd Tariq
2016-05-01
Full Text Available Most of the Brushless DC (BLDC motors drive adopts proportional, integral and derivative (PID controller and pulse width modulation (PWM scheme for speed control. Hence, BLDC motor drive has strong saturation characteristics. The saturation results in a typical windup phenomenon. The paper presents an Antiwindup drive for BLDC motor. An Antiwindup controller (AWC has been used in the paper. AWC has been modeled in MATLAB/Simulink and comparison has been done between conventional PI controller and AWC at different starting loads. Dynamic characteristics of the BLDC motor drive have been examined and results are presented and discussed in detail in this paper. Details of DSP based experimental validation of the simulated results are also presented here.
Directory of Open Access Journals (Sweden)
Maryam Moazen
2016-09-01
Full Text Available In this paper, a predictive direct power control (PDPC method for the brushless doubly fed reluctance generator (BDFRG is proposed. Firstly, the BDFRG active and reactive power equations are derived and then the active and reactive power variations have been predicted within a fixed sampling period. The predicted power variations are used to calculate the required voltage of the secondary winding so that the power errors at the end of the following sampling period are eliminated. Switching pulses are produced using space vector pulse width modulation (SVPWM approach which causes to a fixed switching frequency. The BDFRG model and the proposed control method are simulated in MATLAB/Simulink software. Simulation results indicate the good performance of the control system in tracking of the active and reactive power references in both power step and speed variation conditions. In addition, fast dynamic response and lower output power ripple are other advantages of this control method.
DEFF Research Database (Denmark)
Han, Peng; Cheng, Ming; Jiang, Yunlei
2017-01-01
with a full set of geometrical, electromagnetic, and thermal constraints is developed based on the power flow of generating operation. The optimized results exhibit comparable torque per volume and torque per weight to standard industrial induction machines with the similar size, synchronous speed, and power...... and spatial harmonic distortion. This paper presents a simple design optimization approach for torque/power density optimization of a dual-stator brushless doubly-fed induction generator, which, unlike the modulation types, is inherently free of harmonic-related issues. An analytical average torque model...... loss per-unit area. Mechanical considerations, manufacturing costs, and control aspects are also discussed to show the high potential in superseding existing doubly-fed induction generators. Finite-element analysis and experimental results of a 3.7-kW prototype are used to validate the effectiveness...
Isovector monopole excitation energies
Energy Technology Data Exchange (ETDEWEB)
Bowman, J.D.; Lipparini, E.; Stringary, S.
1987-11-05
Using a hydrodynamical model whose parameters have been adjusted to fit the polarizability and excitation energy of the giant dipole nuclear resonance we predict excitation energies of the isovector monopole resonance. The predicted values are in good agreement with experimental data. The mass dependence of the excitation energy is strongly influenced by nuclear geometry.
Quantum circuits for cryptanalysis
Amento, Brittanney Jaclyn
Finite fields of the form F2 m play an important role in coding theory and cryptography. We show that the choice of how to represent the elements of these fields can have a significant impact on the resource requirements for quantum arithmetic. In particular, we show how the Gaussian normal basis representations and "ghost-bit basis" representations can be used to implement inverters with a quantum circuit of depth O(mlog(m)). To the best of our knowledge, this is the first construction with subquadratic depth reported in the literature. Our quantum circuit for the computation of multiplicative inverses is based on the Itoh-Tsujii algorithm which exploits the property that, in a normal basis representation, squaring corresponds to a permutation of the coefficients. We give resource estimates for the resulting quantum circuit for inversion over binary fields F2 m based on an elementary gate set that is useful for fault-tolerant implementation. Elliptic curves over finite fields F2 m play a prominent role in modern cryptography. Published quantum algorithms dealing with such curves build on a short Weierstrass form in combination with affine or projective coordinates. In this thesis we show that changing the curve representation allows a substantial reduction in the number of T-gates needed to implement the curve arithmetic. As a tool, we present a quantum circuit for computing multiplicative inverses in F2m in depth O(m log m) using a polynomial basis representation, which may be of independent interest. Finally, we change our focus from the design of circuits which aim at attacking computational assumptions on asymmetric cryptographic algorithms to the design of a circuit attacking a symmetric cryptographic algorithm. We consider a block cipher, SERPENT, and our design of a quantum circuit implementing this cipher to be used for a key attack using Grover's algorithm as in [18]. This quantum circuit is essential for understanding the complexity of Grover's algorithm.
Color Coding of Circuit Quantities in Introductory Circuit Analysis Instruction
Reisslein, Jana; Johnson, Amy M.; Reisslein, Martin
2015-01-01
Learning the analysis of electrical circuits represented by circuit diagrams is often challenging for novice students. An open research question in electrical circuit analysis instruction is whether color coding of the mathematical symbols (variables) that denote electrical quantities can improve circuit analysis learning. The present study…
Younis, Mohammad I.
2016-03-10
Embodiments of multi-frequency excitation are described. In various embodiments, a natural frequency of a device may be determined. In turn, a first voltage amplitude and first fixed frequency of a first source of excitation can be selected for the device based on the natural frequency. Additionally, a second voltage amplitude of a second source of excitation can be selected for the device, and the first and second sources of excitation can be applied to the device. After applying the first and second sources of excitation, a frequency of the second source of excitation can be swept. Using the methods of multi- frequency excitation described herein, new operating frequencies, operating frequency ranges, resonance frequencies, resonance frequency ranges, and/or resonance responses can be achieved for devices and systems.
Magnetic Circuit Model combined with Play Model Obtained from Landau-Lifshitz-Gilbert Equation
Tanaka, H.; Nakamura, K.; Ichinokura, O.
2017-10-01
This paper presents a novel magnetic circuit model considering magnetic hysteresis behavior, in which dc hysteresis is expressed by a play model while classical and anomalous eddy current losses are calculated by magnetic circuit elements. We describe an efficient method for obtaining the play model from the minimum measured B-H loops. It is proved that the proposed magnetic circuit model can calculate hysteresis loops under Pulse Width Modulation (PWM) excitation with high accuracy in a short time.
Circuits and Mechanisms for Surround Modulation in Visual Cortex.
Angelucci, Alessandra; Bijanzadeh, Maryam; Nurminen, Lauri; Federer, Frederick; Merlin, Sam; Bressloff, Paul C
2017-07-25
Surround modulation (SM) is a fundamental property of sensory neurons in many species and sensory modalities. SM is the ability of stimuli in the surround of a neuron's receptive field (RF) to modulate (typically suppress) the neuron's response to stimuli simultaneously presented inside the RF, a property thought to underlie optimal coding of sensory information and important perceptual functions. Understanding the circuit and mechanisms for SM can reveal fundamental principles of computations in sensory cortices, from mouse to human. Current debate is centered over whether feedforward or intracortical circuits generate SM, and whether this results from increased inhibition or reduced excitation. Here we present a working hypothesis, based on theoretical and experimental evidence, that SM results from feedforward, horizontal, and feedback interactions with local recurrent connections, via synaptic mechanisms involving both increased inhibition and reduced recurrent excitation. In particular, strong and balanced recurrent excitatory and inhibitory circuits play a crucial role in the computation of SM.
Peacock, W. M.
1973-01-01
The National Aeronautics and Space Administration (NASA), launched ITOS-D with an improved attitude control system. A Hall generator brushless dc torque motor replaced the brush dc torque motor on Tiros-M and ITOS-A. Two CO2 attitude horizon sensors and one mirror replaced the four wideband horizon sensors and two mirrors on ITOS-1 and NOAA-1. Redundant pitch-control electronic boxes containing additional electronic circuitry for earth-splitting and brushless motor electronics were used. A method of generating a spacecraft earth-facing side reference for comparison to the time occurrence of the earth-splitting pulse was used to automatically correct pitch-attitude error. A single rotating flywheel, supported by a single bearing, provided gyroscopic stability and the required momentum interchange to keep one side of the satellite facing the earth. Magnetic torquing against the earth's magnetic field eliminated the requirement for expendable propellants which would limit satellite life in orbit.
Directory of Open Access Journals (Sweden)
Weiran Wang
2013-06-01
Full Text Available In order to improve the performance of bearingless brushless DC motor, a closed-loop suspended force controller combining the discrete space voltage vector modulation is applied and the direct torque control is presented in this paper. Firstly, we increase the number of the control vector to reduce the torque ripple. Then, the suspending equation is constructed which is spired by the direct torque control algorithm. As a result, the closed-loop suspended force controller is built. The simulated and experimental results evaluate the performance of the proposed method. The more advantage is that the proposed algorithm can achieve the fast torque response, reduce the torque ripple, and follow ideal stator flux track. Furthermore, the motor which implants the closed-loop suspended force controller cannot onlyobtain the dynamic response rapidly and displacement control accurately, but also has the characteristics of bearingless brushless DC motor (such as simple structure, high energy efficiency, small volume and low failure rate.
Vibration Damping Circuit Card Assembly
Hunt, Ronald Allen (Inventor)
2016-01-01
A vibration damping circuit card assembly includes a populated circuit card having a mass M. A closed metal container is coupled to a surface of the populated circuit card at approximately a geometric center of the populated circuit card. Tungsten balls fill approximately 90% of the metal container with a collective mass of the tungsten balls being approximately (0.07) M.
GABAergic circuit dysfunctions in neurodevelopmental disorders
Directory of Open Access Journals (Sweden)
Bidisha eChattopadhyaya
2012-05-01
Full Text Available GABAergic interneurons control neuronal excitability, integration, and plasticity. Further, they regulate the generation of temporal synchrony and oscillatory behavior among networks of pyramidal neurons. Such oscillations within and across neural systems are believed to serve various complex functions, such as perception, movement initiation, and memory. Alterations in the development of GABAergic circuits have been implicated in various brain diseases with neurodevelopmental origin. Here, we highlight recent studies suggesting a role for alterations of GABA transmission in the pathophysiology of two neurodevelopmental diseases, schizophrenia and autism. We further discuss how manipulations of GABA signaling may be used for novel therapeutic interventions.
Directory of Open Access Journals (Sweden)
Achmad Abdul Ghoni
2015-12-01
Full Text Available Seiring berjalannya waktu dibutuhkan pengembangan teknologi pada motor penggerak pada kendaraan yang beredar dipasaran. Karena sumber energi fosil merupakan energi yang tidak dapat diperbarui, maka pengembangan kendaraan dengan listrik sebagai sumber energi adalah solusi untuk penghematan energi dimasa depan. Salah satu jenis motor yang tepat untuk digunakan sebagai penggerak kendaraan akan dibahas pada tugas akhir ini, yaitu motor axial flux brushless DC. Pada tugas akhir ini dilakukan pembuatan desain dan analisis simulasi variabel air gap pada motor axial flux brushless DC dengan rating daya output 12 kW, tegangan DC input 400 V, frekuensi 200 Hz, dan kecepatan 2388 rpm. Varasi variabel air gap dilakukan dengan cara membuat jarak air gap pada jari-jari dalam lebih lebar dibandingkan jari-jari luar. Variasi variabel air gap yang diberikan menghasilkan perubahan nilai pada beberapa parameter kelistrikan motor. Dari simulasi yang didapatkan variasi variabel air gap terbaik pada 1,5 mm dengan kompensasi penambahan ketebalan magnet permanen sebesar 5 mm. Hasil dari variabel air gap pada motor axial flux brushless DC adalah rating daya output yang meningkat menjadi 14,5 kW dengan efisiensi 78,8 persen dan core loss sebesar 356,2 W.
Noise-induced multimode behavior in excitable systems
DEFF Research Database (Denmark)
Postnov, D E; Sosnovtseva, Olga; Han, S K
2002-01-01
Based on experiments with electronic circuits, we show how a system of coupled excitable units can possess several noise-induced oscillatory modes. We characterize the multimode organization in terms of the coherence resonance effect. Multiple gain of regularity is found to be related to different...
Lim, Edward C
2013-01-01
Excited States, Volume 2 is a collection of papers that deals with molecules in the excited states. The book describes the geometries of molecules in the excited electronic states. One paper describes the geometries of a diatomic molecule and of polyatomic molecules; it also discusses the determination of the many excited state geometries of molecules with two, three, or four atoms by techniques similar to diatomic spectroscopy. Another paper introduces an ordered theory related to excitons in pure and mixed molecular crystals. This paper also presents some experimental data such as those invo
Wiegerink, Remco J.; Seevinck, Evert; de Jager, Wim
1989-01-01
A monolithic offset cancelling circuit to reduce the offset voltage at an integrated audio-amplifier output is described. This offset voltage is detected using a low-pass filter with a very large time constant for which only one small on-chip capacitor is needed. The circuit was realized with a bipolar cell-based semicustom array. Measurements have shown that a -3-dB bandwidth below 5 Hz can be realized with a capacitor value of 50 pF. The resulting offset voltage at the audio-amplifier outpu...
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
Electronic circuits fundamentals & applications
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
Love, Frank
2006-04-18
An electrical circuit testing device is provided, comprising a case, a digital voltage level testing circuit with a display means, a switch to initiate measurement using the device, a non-shorting switching means for selecting pre-determined electrical wiring configurations to be tested in an outlet, a terminal block, a five-pole electrical plug mounted on the case surface and a set of adapters that can be used for various multiple-pronged electrical outlet configurations for voltages from 100 600 VAC from 50 100 Hz.
Circuit design for reliability
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.
Takeya, Hideaki; Nauta, Bram
2015-01-01
PROBLEM TO BE SOLVED: To provide a power amplifier circuit which has high power efficiency while suppressing a fluctuation of output power relatively to a fluctuation of a power supply voltage in a high-efficiency switching amplifier which operates in a radio frequency band.SOLUTION: A duty ratio
Dickinson, R. M.
1977-01-01
Rectifying antenna is less bulky structure for absorbing transmitted microwave power and converting it into electrical current. Printed-circuit approach, using microstrip technology and circularly polarized antenna, makes polarization orientation unimportant and allows much smaller arrays for given performance. Innovation is particularly useful with proposed electric vehicles powered by beam microwaves.
Superconducting Quantum Circuits
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
ESD analog circuits and design
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
Energy Technology Data Exchange (ETDEWEB)
Amara, Y.
2001-12-01
Double excitation machines are synchronous machines where two excitation circuits coexist: one with permanent magnets and the other with windings. This study shows that double excitation allows to combine the advantages of synchronous machines with winded inductor with those of permanent magnet machines. This concept allows a better dimensioning of the converter-machine set and a better energy management. In order to allow the operation of permanent magnet machines over a wide range of speeds, it is necessary to have a magnetic reaction of the induced circuit of the same order than the excitation flux. On the other hand, the power factor is weaker and the power supply converter is over-dimensioned. The double excitation allows the permanent magnet machines to work over a large speed range with a better power factor, even when the magnetic reaction of the induced circuit is relatively weak with respect to the excitation flux. (J.S.)
Effects of aging on motor cortex excitability.
Oliviero, A; Profice, P; Tonali, P A; Pilato, F; Saturno, E; Dileone, M; Ranieri, F; Di Lazzaro, V
2006-05-01
To determine whether aging is associated with changes in excitability of the cerebral cortex, we evaluated the excitability of the motor cortex with transcranial magnetic stimulation (TMS). We compared TMS related measures obtained in a group of young people with those of a group of old people. Motor evoked potential (MEP) amplitude was significantly smaller in older than in younger controls (1.3+/-0.8 mV versus 2.7+/-1.1 mV; p<0.0071). Mean cortical silent period (CSP) duration was shorter in older than in younger controls (87+/-29 ms versus 147+/-39 ms; p<0.0071). SP duration/MEP amplitude ratios were similar in both groups. Our results are consistent with an impaired efficiency of some intracortical circuits in old age.
Reducing energy with asynchronous circuits
Rivas Barragan, Daniel
2012-01-01
Reducing energy consumption using asynchronous circuits. The elastic clocks approach has been implemented along with a closed-feedback loop in order to achieve a lower energy consumption along with more reliability in integrated circuits.
Explicit logic circuits discriminate neural states.
Directory of Open Access Journals (Sweden)
Lane Yoder
Full Text Available The magnitude and apparent complexity of the brain's connectivity have left explicit networks largely unexplored. As a result, the relationship between the organization of synaptic connections and how the brain processes information is poorly understood. A recently proposed retinal network that produces neural correlates of color vision is refined and extended here to a family of general logic circuits. For any combination of high and low activity in any set of neurons, one of the logic circuits can receive input from the neurons and activate a single output neuron whenever the input neurons have the given activity state. The strength of the output neuron's response is a measure of the difference between the smallest of the high inputs and the largest of the low inputs. The networks generate correlates of known psychophysical phenomena. These results follow directly from the most cost-effective architectures for specific logic circuits and the minimal cellular capabilities of excitation and inhibition. The networks function dynamically, making their operation consistent with the speed of most brain functions. The networks show that well-known psychophysical phenomena do not require extraordinarily complex brain structures, and that a single network architecture can produce apparently disparate phenomena in different sensory systems.
Diode, transistor & fet circuits manual
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
Comparison of Flux Regulation Ability of the Hybrid Excitation Doubly Salient Machines
DEFF Research Database (Denmark)
Chen, ZhiHui; Wang, Bo; Chen, Zhe
2014-01-01
A hybrid excitation doubly salient machine (DSM) (HEDSM) can adjust the air gap flux with the limited field exciting ampere-turns. There are a few studied structures with different air gap flux regulation abilities. In this paper, several HEDSMs with different structures are analyzed by using...... excitation prototype machine is used to conduct the no-load and loading experiments, and the results show the good agreement with the analysis based on the equivalent magnetic circuit....
Directory of Open Access Journals (Sweden)
Sukri M.F.
2016-01-01
Full Text Available The present study presents an experimental investigation on the effect of condenser air inlet temperature and dimensionless parameter of X on the performance of automobile air-conditioning (AAC system using integrated brushless direct current motor-rotary compressor and electronic expansion valve. The other components of AAC system are from original component of AAC system used for medium size passenger car. The experimental results showed that the increment of the condenser air inlet temperature and X caused an increase in condensing temperature, cooling capacity and compressor work, while decreasing the coefficient of performance (COP. Meanwhile, the evaporating temperature increase with the increment of condenser air inlet temperature, but decrease with decrement of X. In general, AAC system have to work at higher value of X in order to produce more cooling capacity, thereby increment in compressor work also occurs due to energy balance. However, at higher value of X, the COP of the system dropped due to dominant increase in compressor power, as opposed to a rise in cooling capacity. Due to this reason, the best operation of this compressor occurs at X = 4.96 for constant T5 (35ºC, or at T5 = 30ºC for constant X (4.96.
Directory of Open Access Journals (Sweden)
Nitin Subramonium A K
2017-03-01
Full Text Available Environmental protection and energy conservations are the main concern of 21st century Asia Pacific developing countries. This concern has compelled to design and develop zero pollution road transportation Electric Vehicles (EVs. The EV system consist of energy storage devices such as battery, fuel cell, ultra-capacitors along with electric propulsion, body of the vehicle and energy management system with the diversified technology of electrical, electronics, mechanical, automotive and chemical engineering. The objective of electric vehicle is to produce commercial viable range, efficient performance, and comfort with safety and reliable operations at cheaper price than its counterpart the Internal Combustion Engine Vehicle (ICEV. The PMBLDC motors are the present choice of automobile industries and researchers because of its high power density, compact size, reliability, with noise free and minimum maintenance requirements. The present state of art Permanent Magnet Brushless DC (PMBLDC Motor drive for the electric vehicle application is studied / reviewed in this paper.. In addition the study also reveals the advancement of the Power Processing Unit (PPU which consists of Microelectronics and Controls (Me and C to produce the super-premium efficiency PMBLDC drive system for EV applications.
Directory of Open Access Journals (Sweden)
Chetan K. Lad
2017-08-01
Full Text Available A commutation torque ripple is generated in a brushless DC motor due to a finite time taken for current transfer between outgoing phase and incoming phase due to the phase inductance. The effect of commutation ripple will be more severe for low voltage high current BLDC drives used for automotive applications. Direct Torque Control (DTC techniques are used to reduce the torque ripple. Two phase conduction with six voltage space vectors and three phase conduction with twelve voltage space vectors with DTC are used to reduce the torque ripple. Twelve Step DTC (TSDTC is capable of reducing torque ripple considerably but at the cost of increased inverter and winding losses. In Six Step DTC (SSDTC the torque ripple is higher than that of TSDTC but with reduced winding and inverter losses. In this paper an attempt has been made to strike a balance between torque ripple and losses. A novel Direct Torque Control with twelve voltage space vector with overlap angle control has been proposed. The proposed method is validated through simulation and experimental results.
Directory of Open Access Journals (Sweden)
Quanwu Li
2016-01-01
Full Text Available High reliability is required for the permanent magnet brushless DC motor (PM-BLDCM in an electrical pump of hypersonic vehicle. The PM-BLDCM is a short-time duty motor with high-power-density. Since thermal equilibrium is not reached for the PM-BLDCM, the temperature distribution is not uniform and there is a risk of local overheating. The winding is a main heat source and its insulation is thermally sensitive, so reducing the winding temperature rise is the key to the improvement of the reliability. In order to reduce the winding temperature rise, an electromagnetic-thermal integrated design optimization method is proposed. The method is based on electromagnetic analysis and thermal transient analysis. The requirements and constraints of electromagnetic and thermal design are considered in this method. The split ratio and the maximum flux density in stator lamination, which are highly relevant to the windings temperature rise, are optimized analytically. The analytical results are verified by finite element analysis (FEA and experiments. The maximum error between the analytical and the FEA results is 4%. The errors between the analytical and measured windings temperature rise are less than 8%. It can be proved that the method can obtain the optimal design accurately to reduce the winding temperature rise.
Yang, Shen; Zhu, Xiaoyong; Xiang, Zixuan; Fan, Deyang; Wu, Wenye; Yin, Jianing
2017-05-01
This paper proposes a new flux-intensifying permanent magnet brushless motor for potential application in electric vehicles. The key of the proposed motor is to adopt the concept of flux-intensifying effect, thus the preferable flux-weakening ability and extended speed range can be achieved. The usage of segmented and relatively thinner permanent magnet (PM) in the proposed motor contributes to the increase of d-axis inductance Ld. In addition, the multilayer flux barriers along q-axis flux path will effectively decrease q-axis inductance Lq. As a result, the unique feature of Ld>Lq can be obtained, which is beneficial to extending the speed range of the proposed motor. Furthermore, the flux-intensifying effect can reduce the risk of irreversible demagnetization in PMs. The electromagnetic performances of the proposed motor are analyzed and investigated in details by using the finite element methods, which demonstrate the excellent flux-weakening capability and wide speed range can be achieved in the proposed FI-PMBL motor.
Lim, Edward C
2013-01-01
Excited States, Volume 4 is a collection of papers that deals with the excited states of molecular activity. One paper investigates the resonance Raman spectroscopy as the key to vibrational-electronic coupling. This paper reviews the basic theory of Raman scattering; it also explains the derivation of the Raman spectra, excitation profiles, and depolarization ratios for simple resonance systems. Another paper reviews the magnetic properties of triplet states, including the zero-field resonance techniques, the high-field experiments, and the spin Hamiltonian. This paper focuses on the magnetic
Nuclear expansion with excitation
Energy Technology Data Exchange (ETDEWEB)
De, J.N. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Samaddar, S.K. [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064 (India); Vinas, X. [Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Centelles, M. [Departament d' Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain)]. E-mail: mario@ecm.ub.es
2006-07-06
The expansion of an isolated hot spherical nucleus with excitation energy and its caloric curve are studied in a thermodynamic model with the SkM{sup *} force as the nuclear effective two-body interaction. The calted results are shown to compare well with the recent experimental data from energetic nuclear collisions. The fluctuations in temperature and density are also studied. They are seen to build up very rapidly beyond an excitation energy of {approx}9 MeV/u. Volume-conserving quadrupole deformation in addition to expansion indicates, however, nuclear disassembly above an excitation energy of {approx}4 MeV/u.
Circuit Bodging : Atari Punk Console
Allen, B.
2009-01-01
Circuit bodging is back! Maxwell is proud to present small, simple, but ultimately lovable little circuits to build for your own, personal pleasure. In this edition we are featuring: The Atari Punk Console. The Atari Punk Console (or APC) is a 555 timer IC based noise maker circuit. The original was
Synthetic in vitro transcription circuits.
Weitz, Maximilian; Simmel, Friedrich C
2012-01-01
With the help of only two enzymes--an RNA polymerase and a ribonuclease--reduced versions of transcriptional regulatory circuits can be implemented in vitro. These circuits enable the emulation of naturally occurring biochemical networks, the exploration of biological circuit design principles and the biochemical implementation of powerful computational models.
High voltage MOSFET switching circuit
McEwan, Thomas E.
1994-01-01
The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET.
Tan, Kuan Yen; Partanen, Matti; Lake, Russell E.; Govenius, Joonas; Masuda, Shumpei; Möttönen, Mikko
2017-05-01
Quantum technology promises revolutionizing applications in information processing, communications, sensing and modelling. However, efficient on-demand cooling of the functional quantum degrees of freedom remains challenging in many solid-state implementations, such as superconducting circuits. Here we demonstrate direct cooling of a superconducting resonator mode using voltage-controllable electron tunnelling in a nanoscale refrigerator. This result is revealed by a decreased electron temperature at a resonator-coupled probe resistor, even for an elevated electron temperature at the refrigerator. Our conclusions are verified by control experiments and by a good quantitative agreement between theory and experimental observations at various operation voltages and bath temperatures. In the future, we aim to remove spurious dissipation introduced by our refrigerator and to decrease the operational temperature. Such an ideal quantum-circuit refrigerator has potential applications in the initialization of quantum electric devices. In the superconducting quantum computer, for example, fast and accurate reset of the quantum memory is needed.
Neuromorphic Silicon Neuron Circuits
Indiveri, Giacomo; Linares-Barranco, Bernabé; Hamilton, Tara Julia; van Schaik, André; Etienne-Cummings, Ralph; Delbruck, Tobi; Liu, Shih-Chii; Dudek, Piotr; Häfliger, Philipp; Renaud, Sylvie; Schemmel, Johannes; Cauwenberghs, Gert; Arthur, John; Hynna, Kai; Folowosele, Fopefolu; Saighi, Sylvain; Serrano-Gotarredona, Teresa; Wijekoon, Jayawan; Wang, Yingxue; Boahen, Kwabena
2011-01-01
Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain–machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance-based Hodgkin–Huxley models to bi-dimensional generalized adaptive integrate and fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips. PMID:21747754
Neuromorphic silicon neuron circuits
Directory of Open Access Journals (Sweden)
Giacomo eIndiveri
2011-05-01
Full Text Available Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain-machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance based Hodgkin-Huxley models to bi-dimensional generalized adaptive Integrate and Fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips.
Tan, Kuan Yen; Partanen, Matti; Lake, Russell E.; Govenius, Joonas; Masuda, Shumpei; Möttönen, Mikko
2017-01-01
Quantum technology promises revolutionizing applications in information processing, communications, sensing and modelling. However, efficient on-demand cooling of the functional quantum degrees of freedom remains challenging in many solid-state implementations, such as superconducting circuits. Here we demonstrate direct cooling of a superconducting resonator mode using voltage-controllable electron tunnelling in a nanoscale refrigerator. This result is revealed by a decreased electron temperature at a resonator-coupled probe resistor, even for an elevated electron temperature at the refrigerator. Our conclusions are verified by control experiments and by a good quantitative agreement between theory and experimental observations at various operation voltages and bath temperatures. In the future, we aim to remove spurious dissipation introduced by our refrigerator and to decrease the operational temperature. Such an ideal quantum-circuit refrigerator has potential applications in the initialization of quantum electric devices. In the superconducting quantum computer, for example, fast and accurate reset of the quantum memory is needed. PMID:28480900
Sketoe, J. G.; Clark, Anthony
2000-01-01
This paper presents a DOD E3 program overview on integrated circuit immunity. The topics include: 1) EMI Immunity Testing; 2) Threshold Definition; 3) Bias Tee Function; 4) Bias Tee Calibration Set-Up; 5) EDM Test Figure; 6) EMI Immunity Levels; 7) NAND vs. and Gate Immunity; 8) TTL vs. LS Immunity Levels; 9) TP vs. OC Immunity Levels; 10) 7805 Volt Reg Immunity; and 11) Seventies Chip Set. This paper is presented in viewgraph form.
Cartography of serotonergic circuits.
Sparta, Dennis R; Stuber, Garret D
2014-08-06
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. Copyright © 2014 Elsevier Inc. All rights reserved.
Changes to the shuttle circuits
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
Nonequilibrium Quantum Simulation in Circuit QED
Raftery, James John
Superconducting circuits have become a leading architecture for quantum computing and quantum simulation. In particular, the circuit QED framework leverages high coherence qubits and microwave resonators to construct systems realizing quantum optics models with exquisite precision. For example, the Jaynes-Cummings model has been the focus of significant theoretical interest as a means of generating photon-photon interactions. Lattices of such strongly correlated photons are an exciting new test bed for exploring non-equilibrium condensed matter physics such as dissipative phase transitions of light. This thesis covers a series of experiments which establish circuit QED as a powerful tool for exploring condensed matter physics with photons. The first experiment explores the use of ultra high speed arbitrary waveform generators for the direct digital synthesis of complex microwave waveforms. This new technique dramatically simplifies the classical control chain for quantum experiments and enables high bandwidth driving schemes expected to be essential for generating interesting steady-states and dynamical behavior. The last two experiments explore the rich physics of interacting photons, with an emphasis on small systems where a high degree of control is possible. The first experiment realizes a two-site system called the Jaynes-Cummings dimer, which undergoes a self-trapping transition where the strong photon-photon interactions block photon hopping between sites. The observation of this dynamical phase transition and the related dissipation-induced transition are key results of this thesis. The final experiment augments the Jaynes-Cummings dimer by redesigning the circuit to include in-situ control over photon hopping between sites using a tunable coupler. This enables the study of the dimer's localization transition in the steady-state regime.
Optimization study on inductive-resistive circuit for broadband piezoelectric energy harvesters
Directory of Open Access Journals (Sweden)
Ting Tan
2017-03-01
Full Text Available The performance of cantilever-beam piezoelectric energy harvester is usually analyzed with pure resistive circuit. The optimal performance of such a vibration-based energy harvesting system is limited by narrow bandwidth around its modified natural frequency. For broadband piezoelectric energy harvesting, series and parallel inductive-resistive circuits are introduced. The electromechanical coupled distributed parameter models for such systems under harmonic base excitations are decoupled with modified natural frequency and electrical damping to consider the coupling effect. Analytical solutions of the harvested power and tip displacement for the electromechanical decoupled model are confirmed with numerical solutions for the coupled model. The optimal performance of piezoelectric energy harvesting with inductive-resistive circuits is revealed theoretically as constant maximal power at any excitation frequency. This is achieved by the scenarios of matching the modified natural frequency with the excitation frequency and equating the electrical damping to the mechanical damping. The inductance and load resistance should be simultaneously tuned to their optimal values, which may not be applicable for very high electromechanical coupling systems when the excitation frequency is higher than their natural frequencies. With identical optimal performance, the series inductive-resistive circuit is recommended for relatively small load resistance, while the parallel inductive-resistive circuit is suggested for relatively large load resistance. This study provides a simplified optimization method for broadband piezoelectric energy harvesters with inductive-resistive circuits.
Optimization study on inductive-resistive circuit for broadband piezoelectric energy harvesters
Tan, Ting; Yan, Zhimiao
2017-03-01
The performance of cantilever-beam piezoelectric energy harvester is usually analyzed with pure resistive circuit. The optimal performance of such a vibration-based energy harvesting system is limited by narrow bandwidth around its modified natural frequency. For broadband piezoelectric energy harvesting, series and parallel inductive-resistive circuits are introduced. The electromechanical coupled distributed parameter models for such systems under harmonic base excitations are decoupled with modified natural frequency and electrical damping to consider the coupling effect. Analytical solutions of the harvested power and tip displacement for the electromechanical decoupled model are confirmed with numerical solutions for the coupled model. The optimal performance of piezoelectric energy harvesting with inductive-resistive circuits is revealed theoretically as constant maximal power at any excitation frequency. This is achieved by the scenarios of matching the modified natural frequency with the excitation frequency and equating the electrical damping to the mechanical damping. The inductance and load resistance should be simultaneously tuned to their optimal values, which may not be applicable for very high electromechanical coupling systems when the excitation frequency is higher than their natural frequencies. With identical optimal performance, the series inductive-resistive circuit is recommended for relatively small load resistance, while the parallel inductive-resistive circuit is suggested for relatively large load resistance. This study provides a simplified optimization method for broadband piezoelectric energy harvesters with inductive-resistive circuits.
Power system with an integrated lubrication circuit
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.
Reversible gates and circuits descriptions
Gracki, Krzystof
2017-08-01
This paper presents basic methods of reversible circuit description. To design reversible circuit a set of gates has to be chosen. Most popular libraries are composed of three types of gates so called CNT gates (Control, NOT and Toffoli). The gate indexing method presented in this paper is based on the CNT gates set. It introduces a uniform indexing of the gates used during synthesis process of reversible circuits. The paper is organized as follows. Section 1 recalls basic concepts of reversible logic. In Section 2 and 3 a graphical representation of the reversible gates and circuits is described. Section 4 describes proposed uniform NCT gates indexing. The presented gate indexing method provides gate numbering scheme independent of lines number of the designed circuit. The solution for a circuit consisting of smaller number of lines is a subset of solution for a larger circuit.
Visual experience modulates spatio-temporal dynamics of circuit activation
Directory of Open Access Journals (Sweden)
Lang eWang
2011-06-01
Full Text Available Persistent reduction in sensory drive in early development results in multiple plastic changes of different cortical synapses. How these experience-dependent modifications affect the spatio-temporal dynamics of signal propagation in neocortical circuits is poorly understood. Here we demonstrate that brief visual deprivation significantly affects the propagation of electrical signals in the primary visual cortex. The spatio-temporal spread of circuit activation upon direct stimulation of its input layer (Layer 4 is reduced, as is the activation of Layer 2/3 – the main recipient of the output from Layer 4. Our data suggest that the decrease in spatio-temporal activation of L2/3 depends on reduced L4 output, and is not intrinsically generated within L2/3. The data shown here suggest that changes in the synaptic components of the visual cortical circuit result not only in alteration of local integration of excitatory and inhibitory inputs, but also in a significant decrease in overall circuit activation. Furthermore, our data indicate a differential effect of visual deprivation on L4 and L2/3, suggesting that while feedforward activation of L2/3 is reduced, its activation by long range, within layer inputs is unaltered. Thus, brief visual deprivation induces experience-dependent circuit re-organization by modulating not only circuit excitability, but also the spatio-temporal patterns of cortical activation within and between layers.
DEFF Research Database (Denmark)
Liu, Yi; Xu, Wei; Xiong, Fei
2017-01-01
system. The positive-and negative-sequence components of the unbalanced power winding (PW) voltage caused by the unbalanced loads are regulated separately. Comprehensive experiments are carried out on a prototype BDFIG by employing the conventional and proposed control schemes. The experimental results......The ship shaft power generation system based on a stand-alone brushless doubly-fed induction generator (BDFIG) have demonstrated excellent saving-energy performance. This paper presents a new control scheme of the stand-alone BDFIG for supplying unbalanced loads in the ship shaft power generation...... verify the good performance of the proposed control scheme....
Ma, Xiaohe; Shen, Songhua
2006-11-01
This paper mainly introduces theoretical analysis and experimental results of instantaneous characteristics on a certain three level brushless three-phase AC synchronous generators. The analysis, modeling and simulations with Simplorer software of Ansoft Company are carried out. It establishes three level generator models, gives theoretical relation matrix equation, and simulates some instantaneous characteristics. Design of the system requires reliable simulation tools with comprehensive component libraries capable of dealing with complex system behavior. The simulation results verify that the proposed system model can efficiently simulate the instantaneous characteristics of the real AC generator system. It gives better design experiences and digital methods for aeronautic constant speed and frequency AC power system.
García Haro, Juan Miguel
2011-01-01
Este proyecto que el CAR inició hace pocos años tiene como objetivo principal el estudio y desarrollo de nuevas tecnologías en el campo de actuación y control automático, que servirá de base para otras futuras investigaciones dentro del centro. La tecnología a la que se hace mención se refiere al control de actuadores basados en motores DC brushless (BLDC Motors) empleando el sistema de hardware embebido CompactRIO y programación LabVIEW de National Instruments. Tradicionalmente se emplea en ...
Optoelectronics circuits manual
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
Krainak, Michael; Merritt, Scott
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.
Integrated circuit cell library
Whitaker, Sterling R. (Inventor); Miles, Lowell H. (Inventor)
2005-01-01
According to the invention, an ASIC cell library for use in creation of custom integrated circuits is disclosed. The ASIC cell library includes some first cells and some second cells. Each of the second cells includes two or more kernel cells. The ASIC cell library is at least 5% comprised of second cells. In various embodiments, the ASIC cell library could be 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 95% or more comprised of second cells.
Electronics circuits and systems
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
Electronics circuits and systems
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
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
Electric circuits problem solver
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
Digital Optical Circuit Technology.
1985-03-01
avait donc pour but de dresser un bilan des recherches; et des raisations intiEressant la technologie des circuits optiques et dudier leurs...experiment. 3. EXPERIMENTAL WAVEGUIDE DEVICE Experiments were performed using carbon disulphide, CS2 , as the nonlinear medium. CS2 has a high non- linear...x 1.60- 1.595- S1.590 15514 16 18 20 22 24 26 28 Temperature (I C) FIGURE 5 REFRACTIVE INDEX OF CARBON DISULPHIDE AT 1 .O6um AS A FUNCTION OF
Digital Optical Circuit Technology
Dove, B. L. (Editor)
1985-01-01
The Proceedings for the 48th Meeting of the AGARD Avionics Panel contain the 18 papers presented a Technical Evaluation Report, and discussions that followed the presentations of papers. Seven papers were presented in the session devoted to optical bistability. Optical logic was addressed by three papers. The session on sources, modulators and demodulators presented three papers. Five papers were given in the final session on all optical systems. The purpose of this Specialists' Meeting was to present the research and development status of digital optical circuit technology and to examine its relevance in the broad context of digital processing, communication, radar, avionics and flight control systems implementation.
Nanofabrication of Plasmonic Circuits Containing Single Photon Sources
Siampour, Hamidreza; Kumar, Shailesh; Bozhevolnyi, Sergey I.
2017-01-01
Nanofabrication of photonic components based on dielectric-loaded surface plasmon-polariton waveguides (DLSPPWs) excited by single nitrogen vacancy (NV) centers in nanodiamonds is demonstrated. DLSPPW circuits are built around NV containing nanodiamonds, which are certified to be single-photon emitters, using electron-beam lithography of hydrogen silsesquioxane (HSQ) resist on silver-coated silicon substrates. A propagation length of ~20 {\\mu}m for the NV single-photon emission is measured wi...
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.
High resolution capacitance detection circuit for rotor micro-gyroscope
Directory of Open Access Journals (Sweden)
Ming-Yuan Ren
2014-03-01
Full Text Available Conventional methods for rotor position detection of micro-gyroscopes include common exciting electrodes (single frequency and common sensing electrodes (frequency multiplex, but they have encountered some problems. So we present a high resolution and low noise pick-off circuit for micro-gyroscopes which utilizes the time multiplex method. The detecting circuit adopts a continuous-time current sensing circuit for capacitance measurement, and its noise analysis of the charge amplifier is introduced. The equivalent output noise power spectral density of phase-sensitive demodulation is 120 nV/Hz1/2. Tests revealed that the whole circuitry has a relative capacitance resolution of 1 × 10−8.
Emergence of task-dependent representations in working memory circuits
Directory of Open Access Journals (Sweden)
Cristina eSavin
2014-05-01
Full Text Available A wealth of experimental evidence suggests that working memory circuits preferentially represent information that is behaviorally relevant. Still, we are missing a mechanistic account of how these representations come about. Here we provide a simple explanation for a range of experimental findings, in light of prefrontal circuits adapting to task constraints by reward-dependent learning. In particular, we model a neural network shaped by reward-modulated spike-timing dependent plasticity (r-STDP and homeostatic plasticity (intrinsic excitability and synaptic scaling. We show that the experimentally-observed neural representations naturally emerge in an initially unstructured circuit as it learns to solve several working memory tasks. These results point to a critical, and previously unappreciated, role for reward-dependent learning in shaping prefrontal cortex activity.
Selective serotonergic excitation of callosal projection neurons
Directory of Open Access Journals (Sweden)
Daniel eAvesar
2012-03-01
Full Text Available Serotonin (5-HT acting as a neurotransmitter in the cerebral cortex is critical for cognitive function, yet how 5-HT regulates information processing in cortical circuits is not well understood. We tested the serotonergic responsiveness of layer 5 pyramidal neurons (L5PNs of the mouse medial prefrontal cortex (mPFC, and found 3 distinct response types: long-lasting 5-HT1A (1A receptor-dependent inhibitory responses (84% of L5PNs, 5-HT2A (2A receptor-dependent excitatory responses (9%, and biphasic responses in which 2A-dependent excitation followed brief inhibition (5%. Relative to 5-HT-inhibited neurons, those excited by 5-HT had physiological properties characteristic of callosal/commissural (COM neurons that project to the contralateral cortex. We tested whether serotonergic responses in cortical pyramidal neurons are correlated with their axonal projection pattern using retrograde fluorescent labeling of COM and corticopontine-projecting (CPn neurons. 5-HT generated excitatory or biphasic responses in all 5-HT-responsive layer 5 COM neurons. Conversely, CPn neurons were universally inhibited by 5-HT. Serotonergic excitation of COM neurons was blocked by the 2A antagonist MDL 11939, while serotonergic inhibition of CPn neurons was blocked by the 1A antagonist WAY 100635, confirming a role for these two receptor subtypes in regulating pyramidal neuron activity. Selective serotonergic excitation of COM neurons was not layer-specific, as COM neurons in layer 2/3 were also selectively excited by 5-HT relative to their non-labeled pyramidal neuron neighbors. Because neocortical 2A receptors are implicated in the etiology and pathophysiology of schizophrenia, we propose that COM neurons may represent a novel cellular target for intervention in psychiatric disease.
Hsu, John S [Oak Ridge, TN
2005-12-06
A method and apparatus in which a rotor (11) and a stator (17) define a radial air gap (20) for receiving AC flux and at least one, and preferably two, DC excitation assemblies (23, 24) are positioned at opposite ends of the rotor (20) to define secondary air gaps (21, 22). Portions of PM material (14a, 14b) are provided as boundaries separating the rotor pole portions (12a, 12b) of opposite polarity from other portions of the rotor (11) and from each other to define PM poles (12a, 12b) for conveying the DC flux to or from the primary air gap (20) and for inhibiting flux from leaking from the pole portions prior to reaching the primary air gap (20). The portions of PM material (14a, 14b) are spaced from each other so as to include reluctance poles (15) of ferromagnetic material between the PM poles (12a, 12b) to interact with the AC flux in the primary-air gap (20).
Wang, Yaxin; Logan, Thomas G; Smith, P Alex; Hsu, Po-Lin; Cohn, William E; Xu, Liping; McMahon, Richard A
2017-10-01
The IntraVAD is a miniature intra-aortic ventricular assist device (VAD) designed to work in series with the compromised left ventricle. A reverse-rotation control (RRc) mode has been developed to increase myocardial perfusion and reduce ventricular volume. The RRc mode includes forward rotation in systole and reverse rotation in diastole, which requires the IntraVAD to periodically reverse its rotational direction in synchrony with the cardiac cycle. This periodic reversal leads to changes in pressure force over the impeller, which makes the entire system less stable. To eliminate the mechanical wear of a contact bearing and provide active control over the axial position of the rotor, a miniature magnetically levitated bearing (i.e., the PM-Coil module) composed of two concentric permanent magnetic (PM) rings and a pair of coils-one on each side-was proposed to provide passive radial and active axial rotor stabilization. In the early design stage, the numerical finite element method (FEM) was used to optimize the geometry of the brushless DC (BLDC) motor and the maglev module, but constructing a new model each time certain design parameters were adjusted required substantial computation time. Because the design criteria for the module had to be modified to account for the magnetic force produced by the motor and for the hemodynamic changes associated with pump operation, a simplified analytic expression was derived for the expected magnetic forces. Suitable bearings could then be designed capable of overcoming these forces without repeating the complicated FEM simulation for the motor. Using this method at the initial design stage can inform the design of the miniature maglev BLDC motor for the proposed pulsatile axial-flow VAD. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.
Hobson, D W; Woller, W; Anderson, L; Guthery, E
1998-10-01
Since the introduction in the 1970s of surgical hand scrub formulations that contain 4% chlorhexidine gluconate (CHG), new surgical scrub formulations that have improved efficacy, persistence, or significantly improved use characteristics have not been forthcoming. In addition, the manufacturer's labeling for popular hand scrub products generally requires scrub times in excess of 6 minutes, whereas current practical needs call for products with substantially shorter scrub times. A new alcohol-based surgical scrub formulation, which has ingredients that provide emollient, surfactant, and antimicrobial persistence characteristics to complement the rapid and broad-spectrum antiseptic qualities of alcohol, has been developed in an effort to address these current practical needs. The relative efficacy of a new alcohol-based surgical scrub formulation that contains ingredients that provide surfactant and antimicrobial persistence characteristics was compared with that of commercial 4% CHG and 7.5% povidone iodine (PVPI) formulations with use of human subjects. Hand antimicrobial count sampling was performed by using standardized "glove juice" methodology. The efficacy and persistence results of the new formulation showed statistically significant improvement over both CHG and PVPI at a substantially lessened scrub time (3 minutes). In addition, use of the new formulation without a scrub brush produced results statistically similar to 3-minute applications with either a brush or a sponge. The new alcohol-based formulation demonstrates promise as a new surgical hand scrub formulation with antimicrobial and use characteristics that are significantly improved over current CHG and PVPI formulations. These studies demonstrate the suitability of this formulation for use as a surgical hand scrub and for brushless application.
Simpson, Michael L; Cox, Chris D; Allen, Michael S; McCollum, James M; Dar, Roy D; Karig, David K; Cooke, John F
2009-01-01
Noise biology focuses on the sources, processing, and biological consequences of the inherent stochastic fluctuations in molecular transitions or interactions that control cellular behavior. These fluctuations are especially pronounced in small systems where the magnitudes of the fluctuations approach or exceed the mean value of the molecular population. Noise biology is an essential component of nanomedicine where the communication of information is across a boundary that separates small synthetic and biological systems that are bound by their size to reside in environments of large fluctuations. Here we review the fundamentals of the computational, analytical, and experimental approaches to noise biology. We review results that show that the competition between the benefits of low noise and those of low population has resulted in the evolution of genetic system architectures that produce an uneven distribution of stochasticity across the molecular components of cells and, in some cases, use noise to drive biological function. We review the exact and approximate approaches to gene circuit noise analysis and simulation, and review many of the key experimental results obtained using flow cytometry and time-lapse fluorescent microscopy. In addition, we consider the probative value of noise with a discussion of using measured noise properties to elucidate the structure and function of the underlying gene circuit. We conclude with a discussion of the frontiers of and significant future challenges for noise biology. (c) 2009 John Wiley & Sons, Inc.
Arithmetic circuits for DSP applications
Stouraitis, Thanos
2017-01-01
Arithmetic Circuits for DSP Applications is a complete resource on arithmetic circuits for digital signal processing (DSP). It covers the key concepts, designs and developments of different types of arithmetic circuits, which can be used for improving the efficiency of implementation of a multitude of DSP applications. Each chapter includes various applications of the respective class of arithmetic circuits along with information on the future scope of research. Written for students, engineers, and researchers in electrical and computer engineering, this comprehensive text offers a clear understanding of different types of arithmetic circuits used for digital signal processing applications. The text includes contributions from noted researchers on a wide range of topics, including a review o circuits used in implementing basic operations like additions and multiplications; distributed arithmetic as a technique for the multiplier-less implementation of inner products for DSP applications; discussions on look ...
Integrated circuit cooled turbine blade
Energy Technology Data Exchange (ETDEWEB)
Lee, Ching-Pang; Jiang, Nan; Um, Jae Y.; Holloman, Harry; Koester, Steven
2017-08-29
A turbine rotor blade includes at least two integrated cooling circuits that are formed within the blade that include a leading edge circuit having a first cavity and a second cavity and a trailing edge circuit that includes at least a third cavity located aft of the second cavity. The trailing edge circuit flows aft with at least two substantially 180-degree turns at the tip end and the root end of the blade providing at least a penultimate cavity and a last cavity. The last cavity is located along a trailing edge of the blade. A tip axial cooling channel connects to the first cavity of the leading edge circuit and the penultimate cavity of the trailing edge circuit. At least one crossover hole connects the penultimate cavity to the last cavity substantially near the tip end of the blade.
Automated Design of Quantum Circuits
Williams, Colin P.; Gray, Alexander G.
2000-01-01
In order to design a quantum circuit that performs a desired quantum computation, it is necessary to find a decomposition of the unitary matrix that represents that computation in terms of a sequence of quantum gate operations. To date, such designs have either been found by hand or by exhaustive enumeration of all possible circuit topologies. In this paper we propose an automated approach to quantum circuit design using search heuristics based on principles abstracted from evolutionary genetics, i.e. using a genetic programming algorithm adapted specially for this problem. We demonstrate the method on the task of discovering quantum circuit designs for quantum teleportation. We show that to find a given known circuit design (one which was hand-crafted by a human), the method considers roughly an order of magnitude fewer designs than naive enumeration. In addition, the method finds novel circuit designs superior to those previously known.
Agranovich, Vladimir M
2009-01-01
During the last decade our expertise in nanotechnology has advanced considerably. The possibility of incorporating in the same nanostructure different organic and inorganic materials has opened up a promising field of research, and has greatly increased the interest in the study of properties of excitations in organic materials. In this book not only the fundamentals of Frenkel exciton and polariton theory are described, but also the electronic excitations and electronic energytransfers in quantum wells, quantum wires and quantum dots, at surfaces, at interfaces, in thin films, in multilayers,
Optical readout of coupling between a nanomembrane and an LC circuit at room temperature
DEFF Research Database (Denmark)
Bagci, T.; Simonsen, A.; Zeuthen, E.
2013-01-01
via a mechanical interface is of potential interest, as it would allow for low noise optical detection and laser cooling of weak electrical excitations. In a recent paper [4], a scheme was proposed for room temperature applications where a membrane converts rf electrical excitations in an LC circuit...... to optical excitations in a high finesse cavity.In this work, we have experimentally realized both optical and electrical detection of coupling in a roomtemperature electromechanical system composed of an LC circuit and a 100-nm thick SiN nanomembrane coated by 50 nm Aluminum. We follow an approach similar...... to the one described in [4] (cf. Fig 1a): The displacement of the high Q membrane is capacitively coupled to a plate capacitor that is connected in parallel to a ferrite inductor. A change in capacitance alters the LC resonance frequency, thereby creating coupling between the membrane and the LC circuit...
Excitation Methods for Bridge Structures
Energy Technology Data Exchange (ETDEWEB)
Farrar, C.R.; Duffy, T.A.; Cornwell, P.J.; Doebling, S.W.
1999-02-08
This paper summarizes the various methods that have been used to excited bridge structures during dynamic testing. The excitation methods fall into the general categories of ambient excitation methods and measured-input excitation methods. During ambient excitation the input to the bridge is not directly measured. In contrast, as the category label implies, measured-input excitations are usually applied at a single location where the force input to the structure can be monitored. Issues associated with using these various types of measurements are discussed along with a general description of the various excitation methods.
The printed circuit board industry and innovations for the 1990s
Castrovilla, Joseph A.
1989-04-01
The science of plastic materials for printed circuit boards is constantly improving to meet the demand for better electrical and mechanical performance of electrical systems. Epoxy resins will continue to dominate the printed circuit market through 1992. However, thermoplastics will make inroads due to their superior mechanical, thermal and electrical properties and compatibility with the surface-mount process. Through 1992, it is expected that laminates will resume a positive growth, but with most of the increase in value of printed circuit boards coming from increased circuit density on smaller surface volumes. During the 1990s, the function of the printed circuit board will change. The long-term role is for the circuit board to become part of the circuit. In some cases, the printed circuit board will provide not the second level of interconnection but the third level as future customization will move the circuit board function to silicon. New technologies will change the nature of printed circuit boards and the way firms in the industry do business. Board fabricators and consumers who prepare to adopt these technologies will benefit from exciting business opportunities.
Synthetic biology: integrated gene circuits.
Nandagopal, Nagarajan; Elowitz, Michael B
2011-09-02
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 are providing fundamental insights into the regulatory architecture, dynamics, and evolution of genetic circuits and enabling new levels of control across diverse biological systems.
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......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...
Precision bridge circuit using a temperature sensor
Mount, Bruce E. (Inventor)
1992-01-01
A precision bridge measurement circuit connected to a current source providing a linear output voltage versus resistance change of a variable resistance (resistance temperature transducer) including a voltage follower in one branch of the bridge so that the zero setting of the transducer resistance does not depend upon the current source or upon an excitation voltage. The zero setting depends only on the precision and stability of the three resistances. By connecting the output of an instrumentation amplifier to a feedback resistor and then to the output of the voltage follower, minor nonlinearities in the resistance-vs-temperature output of a resistance-temperature transducer, such as a platinum temperature sensor, may be corrected. Sensors which have nonlinearity opposite in polarity to platinum, such as nickel-iron sensors, may be linearized by inserting an inverting amplifier into the feedback loop.
Respiratory circuits: function, mechanisms, topology, and pathology.
Mironov, Sergej
2009-04-01
Neuroscientists have long sought to understand how circuits in the nervous system are organized to generate the precise neural outputs that underlie particular behaviors. Recent studies deepened our understanding of the mechanisms responsible for the generation of the rhythmic output for breathing. Here, the author focuses on issues that are pertinent for the respiratory network and considers its organization and how it derives the functional output. The author discusses pacemaker and network mechanisms of rhythm generation, which are now combined into a novel concept of emergent network activity due to coherent excitation of pacemaker groups. He discusses subcellular basis of this hypothesis and possible mechanisms of synchronization within respiratory network. These new findings in respiratory neuroscience are further applied to explain modifications in breathing during hypoxia and possible origins of respiratory disorders that may be acquired during neural development and aging.
Directory of Open Access Journals (Sweden)
Hassan Moradi CheshmehBeigi
2015-12-01
Full Text Available Abstract. This paper presents the design optimization and accurate electromagnetic field analysis of an 18-12 there phase Brushless dc motor (BLDCM by using a three-dimensional Finite-Element analysis. Proposed motor will provide a wide range of air-gap flux control by a dc assisted field winding which is replaced with the permanent magnet in the rotor structure. In proposed BLDCM a simple dc current control is used and no brushes or slip rings are required to perform this control. To achieve the required performance within a specified space envelope, the physical dimensions of the proposed configuration were optimized; subject to maximize the average output power. Proposed 18-12 BLDCM configuration has been compared with a 9-6 BLDCM configuration. To evaluate the motor performance, the numerical techniques have been utilized. In the numerical part, 3-D Finite Element (FE analysis has been carried out using a MagNet CAD package (Infolytica Corporation Ltd. for two type of BLDCM to confirm the accuracy and the efficacy of the proposed design procedure. The analysis results demonstrate the effectiveness of the proposed machine design methodology. Keywords: FE Analysis; Field analysis; Brushless Dc Motor
Parcell, L. A.; Mceachran, R. P.; Stauffer, A. D.
1990-01-01
The differential and total cross section for the excitation of the 3s1P10 and 3p1P1 states of neon by positron impact were calculated using a distorted-wave approximation. The results agree well with experimental conclusions.
Hardness and excitation energy
Indian Academy of Sciences (India)
It is shown that the first excitation energy can be given by the Kohn-Sham hardness (i.e. the energy difference of the ground-state lowest unoccupied and highest occupied levels) plus an extra term coming from the partial derivative of the ensemble exchange-correlation energy with respect to the weighting factor in the ...
Excitation of Stellar Pulsations
DEFF Research Database (Denmark)
Houdek, G.
2012-01-01
In this review I present an overview of our current understanding of the physical mechanisms that are responsible for the excitation of pulsations in stars with surface convection zones. These are typically cooler stars such as the δ Scuti stars, and stars supporting solar-like oscillations....
Memristor Circuits and Systems
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
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...
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.
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...
Improved Underwater Excitation-Emission Matrix Fluorometer
Moore, Casey; daCunha, John; Rhoades, Bruce; Twardowski, Michael
2007-01-01
A compact, high-resolution, two-dimensional excitation-emission matrix fluorometer (EEMF) has been designed and built specifically for use in identifying and measuring the concentrations of organic compounds, including polluting hydrocarbons, in natural underwater settings. Heretofore, most EEMFs have been designed and built for installation in laboratories, where they are used to analyze the contents of samples collected in the field and brought to the laboratories. Because the present EEMF can be operated in the field, it is better suited to measurement of spatially and temporally varying concentrations of substances of interest. In excitation-emission matrix (EEM) fluorometry, fluorescence is excited by irradiating a sample at one or more wavelengths, and the fluorescent emission from the sample is measured at multiple wavelengths. When excitation is provided at only one wavelength, the technique is termed one-dimensional (1D) EEM fluorometry because the resulting matrix of fluorescence emission data (the EEM) contains only one row or column. When excitation is provided at multiple wavelengths, the technique is termed two-dimensional (2D) EEM fluorometry because the resulting EEM contains multiple rows and columns. EEM fluorometry - especially the 2D variety - is well established as a means of simultaneously detecting numerous dissolved and particulate compounds in water. Each compound or pool of compounds has a unique spectral fluorescence signature, and each EEM is rich in information content, in that it can contain multiple fluorescence signatures. By use of deconvolution and/or other mixture-analyses techniques, it is often possible to isolate the spectral signature of compounds of interest, even when their fluorescence spectra overlap. What distinguishes the present 2D EEMF over prior laboratory-type 2D EEMFs are several improvements in packaging (including a sealed housing) and other aspects of design that render it suitable for use in natural underwater
Graphene-on-silicon hybrid plasmonic-photonic integrated circuits.
Xiao, Ting-Hui; Cheng, Zhenzhou; Goda, Keisuke
2017-06-16
Graphene surface plasmons (GSPs) have shown great potential in biochemical sensing, thermal imaging, and optoelectronics. To excite GSPs, several methods based on the near-field optical microscope and graphene nanostructures have been developed in the past few years. However, these methods suffer from their bulky setups and low GSP-excitation efficiency due to the short interaction length between free-space vertical excitation light and the atomic layer of graphene. Here we present a CMOS-compatible design of graphene-on-silicon hybrid plasmonic-photonic integrated circuits that achieve the in-plane excitation of GSP polaritons as well as localized surface plasmon (SP) resonance. By employing a suspended membrane slot waveguide, our design is able to excite GSP polaritons on a chip. Moreover, by utilizing a graphene nanoribbon array, we engineer the transmission spectrum of the waveguide by excitation of localized SP resonance. Our theoretical and computational study paves a new avenue to enable, modulate, and monitor GSPs on a chip, potentially applicable for the development of on-chip electro-optic devices.
Square-wave excitation of a linear oscillator
Butikov, Eugene I.
2004-04-01
The forced oscillations of a torsion spring pendulum excited by an external square-wave external torque are discussed. Two different ways of determining the steady-state response of the oscillator are described and compared. The behavior of this familiar mechanical system can help a student better understand why and how a LCR-circuit transfers a square-wave voltage from input to output with a distortion of its shape.
Digital circuits using universal logic gates
Whitaker, Sterling R. (Inventor); Miles, Lowell H. (Inventor); Cameron, Eric G. (Inventor); Donohoe, Gregory W. (Inventor); Gambles, Jody W. (Inventor)
2004-01-01
According to the invention, a digital circuit design embodied in at least one of a structural netlist, a behavioral netlist, a hardware description language netlist, a full-custom ASIC, a semi-custom ASIC, an IP core, an integrated circuit, a hybrid of chips, one or more masks, a FPGA, and a circuit card assembly is disclosed. The digital circuit design includes first and second sub-circuits. The first sub-circuits comprise a first percentage of the digital circuit design and the second sub-circuits comprise a second percentage of the digital circuit design. Each of the second sub-circuits is substantially comprised of one or more kernel circuits. The kernel circuits are comprised of selection circuits. The second percentage is at least 5%. In various embodiments, the second percentage could be at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%.
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...
Compact Circuit Preprocesses Accelerometer Output
Bozeman, Richard J., Jr.
1993-01-01
Compact electronic circuit transfers dc power to, and preprocesses ac output of, accelerometer and associated preamplifier. Incorporated into accelerometer case during initial fabrication or retrofit onto commercial accelerometer. Made of commercial integrated circuits and other conventional components; made smaller by use of micrologic and surface-mount technology.
Comminution circuits for compact itabirites
Directory of Open Access Journals (Sweden)
Pedro Ferreira Pinto
Full Text Available Abstract In the beneficiation of compact Itabirites, crushing and grinding account for major operational and capital costs. As such, the study and development of comminution circuits have a fundamental importance for feasibility and optimization of compact Itabirite beneficiation. This work makes a comparison between comminution circuits for compact Itabirites from the Iron Quadrangle. The circuits developed are: a crushing and ball mill circuit (CB, a SAG mill and ball mill circuit (SAB and a single stage SAG mill circuit (SSSAG. For the SAB circuit, the use of pebble crushing is analyzed (SABC. An industrial circuit for 25 million tons of run of mine was developed for each route from tests on a pilot scale (grinding and industrial scale. The energy consumption obtained for grinding in the pilot tests was compared with that reported by Donda and Bond. The SSSAG route had the lowest energy consumption, 11.8kWh/t and the SAB route had the highest energy consumption, 15.8kWh/t. The CB and SABC routes had a similar energy consumption of 14.4 kWh/t and 14.5 kWh/t respectively.
Adult neurogenesis modifies excitability of the dentate gyrus
Directory of Open Access Journals (Sweden)
Taruna eIkrar
2013-12-01
Full Text Available Adult-born dentate granule neurons contribute to memory encoding functions of the dentate gyrus (DG such as pattern separation. However, local circuit-mechanisms by which adult-born neurons partake in this process are poorly understood. Computational, neuroanatomical and electrophysiological studies suggest that sparseness of activation in the granule cell layer (GCL is conducive for pattern separation. A sparse coding scheme is thought to facilitate the distribution of similar entorhinal inputs across the GCL to decorrelate overlapping representations and minimize interference. Here we used fast voltage-sensitive dye (VSD imaging combined with laser photostimulation and electrical stimulation to examine how selectively increasing adult DG neurogenesis influences local circuit activity and excitability. We show that DG of mice with more adult-born neurons exhibits decreased strength of neuronal activation and more restricted excitation spread in GCL while maintaining effective output to CA3c. Conversely, blockade of adult hippocampal neurogenesis changed excitability of the DG in the opposite direction. Analysis of GABAergic inhibition onto mature dentate granule neurons in the DG of mice with more adult-born neurons shows a modest readjustment of perisomatic inhibitory synaptic gain without changes in overall inhibitory tone, presynaptic properties or GABAergic innervation pattern. Retroviral labeling of connectivity in mice with more adult-born neurons showed increased number of excitatory synaptic contacts of adult-born neurons onto hilar interneurons. Together, these studies demonstrate that adult hippocampal neurogenesis modifies excitability of mature dentate granule neurons and that this non-cell autonomous effect may be mediated by local circuit mechanisms such as excitatory drive onto hilar interneurons. Modulation of DG excitability by adult-born dentate granule neurons may enhance sparse coding in the GCL to influence pattern
Photodiode circuits for retinal prostheses.
Loudin, J D; Cogan, S F; Mathieson, K; Sher, A; Palanker, D V
2011-10-01
Photodiode circuits show promise for the development of high-resolution retinal prostheses. While several of these systems have been constructed and some even implanted in humans, existing descriptions of the complex optoelectronic interaction between light, photodiode, and the electrode/electrolyte load are limited. This study examines this interaction in depth with theoretical calculations and experimental measurements. Actively biased photoconductive and passive photovoltaic circuits are investigated, with the photovoltaic circuits consisting of one or more diodes connected in series, and the photoconductive circuits consisting of a single diode in series with a pulsed bias voltage. Circuit behavior and charge injection levels were markedly different for platinum and sputtered iridium-oxide film (SIROF) electrodes. Photovoltaic circuits were able to deliver 0.038 mC/cm(2) (0.75 nC/phase) per photodiode with 50- μm platinum electrodes, and 0.54-mC/cm(2) (11 nC/phase) per photodiode with 50-μ m SIROF electrodes driven with 0.5-ms pulses of light at 25 Hz. The same pulses applied to photoconductive circuits with the same electrodes were able to deliver charge injections as high as 0.38 and 7.6 mC/cm(2) (7.5 and 150 nC/phase), respectively. We demonstrate photovoltaic stimulation of rabbit retina in-vitro, with 0.5-ms pulses of 905-nm light using peak irradiance of 1 mW/mm(2). Based on the experimental data, we derive electrochemical and optical safety limits for pixel density and charge injection in various circuits. While photoconductive circuits offer smaller pixels, photovoltaic systems do not require an external bias voltage. Both classes of circuits show promise for the development of high-resolution optoelectronic retinal prostheses.
Pancholi, S C
2011-01-01
By providing the reader with a foundational background in high spin nuclear structure physics and exploring exciting current discoveries in the field, this book presents new phenomena in a clear and compelling way. The quest for achieving the highest spin states has resulted in some remarkable successes which this monograph will address in comprehensive detail. The text covers an array of pertinent subject matter, including the rotational alignment and bandcrossings, magnetic rotation, triaxial strong deformation and wobbling motion and chirality in nuclei. Dr. Pancholi offers his readers a clearly-written and up-to-date treatment of the topics covered. The prerequisites for a proper appreciation are courses in nuclear physics and nuclear models and measurement techniques of observables like gamma-ray energies, intensities, multi-fold coincidences, angular correlations or distributions, linear polarization, internal conversion coefficients, short lifetime (pico-second range) of excited states etc. and instrum...
Copelli, M.; Campos, P. R. A.
2007-04-01
When a simple excitable system is continuously stimulated by a Poissonian external source, the response function (mean activity versus stimulus rate) generally shows a linear saturating shape. This is experimentally verified in some classes of sensory neurons, which accordingly present a small dynamic range (defined as the interval of stimulus intensity which can be appropriately coded by the mean activity of the excitable element), usually about one or two decades only. The brain, on the other hand, can handle a significantly broader range of stimulus intensity, and a collective phenomenon involving the interaction among excitable neurons has been suggested to account for the enhancement of the dynamic range. Since the role of the pattern of such interactions is still unclear, here we investigate the performance of a scale-free (SF) network topology in this dynamic range problem. Specifically, we study the transfer function of disordered SF networks of excitable Greenberg-Hastings cellular automata. We observe that the dynamic range is maximum when the coupling among the elements is critical, corroborating a general reasoning recently proposed. Although the maximum dynamic range yielded by general SF networks is slightly worse than that of random networks, for special SF networks which lack loops the enhancement of the dynamic range can be dramatic, reaching nearly five decades. In order to understand the role of loops on the transfer function we propose a simple model in which the density of loops in the network can be gradually increased, and show that this is accompanied by a gradual decrease of dynamic range.
The analysis of an operating mode of the asynchronous generator with capacitor excitation
Directory of Open Access Journals (Sweden)
Postoronca S.
2008-08-01
Full Text Available On the basis of a symbolical method of calculation of electric circuits the analysis of features of work of the three-phase asynchronous generator with two windings on статоре and capacitor excitation is executed. Results of the analysis of influence on a phase corner of a current and voltage of a windings of excitation of the generator are submitted at change of its loading from a mode of idling up to a mode of short circuit. Recommendations on stabilization of a target voltage of the generator are formulated at change of its loading.
Variational integrators for electric circuits
Energy Technology Data Exchange (ETDEWEB)
Ober-Blöbaum, Sina, E-mail: sinaob@math.upb.de [Computational Dynamics and Optimal Control, University of Paderborn (Germany); Tao, Molei [Courant Institute of Mathematical Sciences, New York University (United States); Cheng, Mulin [Applied and Computational Mathematics, California Institute of Technology (United States); Owhadi, Houman; Marsden, Jerrold E. [Control and Dynamical Systems, California Institute of Technology (United States); Applied and Computational Mathematics, California Institute of Technology (United States)
2013-06-01
In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electric 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 (which are usually the method of choice for the simulation of electric circuits) shows that even for simple LCR circuits, a better energy behavior and frequency spectrum preservation can be observed using the developed variational integrator.
Experimental Device for Learning of Logical Circuit Design using Integrated Circuits
石橋, 孝昭
2012-01-01
This paper presents an experimental device for learning of logical circuit design using integrated circuits and breadboards. The experimental device can be made at a low cost and can be used for many subjects such as logical circuits, computer engineering, basic electricity, electrical circuits and electronic circuits. The proposed device is effective to learn the logical circuits than the usual lecture.
30 CFR 77.800 - High-voltage circuits; circuit breakers.
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 circuit...
The Maplin electronic circuits handbook
Tooley, Michael
1990-01-01
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
den Boon, F.S.; Werkman, T.R.; Schaafsma-Zhao, Q.; Houthuijs, K.; Vitalis, T.; Kruse, C.G.; Wadman, W.J.; Chameau, P.
2015-01-01
Activation of the endocannabinoid (eCB) system by exogenous cannabinoids (drug abuse) can alter the physiology of the brain circuits involved in higher-order cognitive functions such as the medial prefrontal cortex (mPFC). A proper balance between excitation and inhibition (E/I balance) is critical
Circuit design on plastic foils
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.
Directory of Open Access Journals (Sweden)
Chengde Tong
2017-05-01
Full Text Available The axial-flux magnetic-field-modulated brushless double-rotor machine (MFM-BDRM is a possible alternative as a power-split device for hybrid electric vehicles (HEVs. However, the existence of large axial force may lead to assembly problems and rich inner air-gap harmonics could result in high PM loss and low efficiency. This paper proposes a novel axial-flux MFM-BDRM with improved PM rotor structure. 2-D analytical method to predict the magnetic-field distribution of the proposed MFM-BDRM is developed and the design procedure of the proposed machine is illustrated. The impact of key geometrical parameters on axial force and torque is investigated. To evaluate the advantage of the proposed machine, a comparison is made with a conventional one with respect to electromagnetic performances. Results show that the proposed machine is effective in reducing PM eddy loss and axial force by 60% and 35%, respectively.
Luo, Shaohua; Wu, Songli; Gao, Ruizhen
2015-07-01
This paper investigates chaos control for the brushless DC motor (BLDCM) system by adaptive dynamic surface approach based on neural network with the minimum weights. The BLDCM system contains parameter perturbation, chaotic behavior, and uncertainty. With the help of radial basis function (RBF) neural network to approximate the unknown nonlinear functions, the adaptive law is established to overcome uncertainty of the control gain. By introducing the RBF neural network and adaptive technology into the dynamic surface control design, a robust chaos control scheme is developed. It is proved that the proposed control approach can guarantee that all signals in the closed-loop system are globally uniformly bounded, and the tracking error converges to a small neighborhood of the origin. Simulation results are provided to show that the proposed approach works well in suppressing chaos and parameter perturbation.
Demerdash, N. A.; Nehl, T. W.
1980-01-01
A comprehensive digital model for the analysis and possible optimization of the closed loop dynamic (instantaneous) performance of a power conditioner fed, brushless dc motor powered, electromechanical actuator system (EMA) is presented. This model was developed for the simulation of the dynamic performance of an actual prototype EMA built for NASA-JSC as a possible alternative to hydraulic actuators for consideration in Space Shuttle Orbiter applications. Excellent correlation was achieved between numerical model simulation and experimental test results obtained from the actual hardware. These results include: various current and voltage waveforms in the machine-power conditioner (MPC) unit, flap position as well as other control loop variables in response to step commands of change of flap position. These results with consequent conclusions are detailed in the paper.
Energy Technology Data Exchange (ETDEWEB)
Luo, Shaohua [School of Automation, Chongqing University, Chongqing 400044 (China); Department of Mechanical Engineering, Chongqing Aerospace Polytechnic, Chongqing, 400021 (China); Wu, Songli [Department of Mechanical Engineering, Chongqing Aerospace Polytechnic, Chongqing, 400021 (China); Gao, Ruizhen [School of Automation, Chongqing University, Chongqing 400044 (China)
2015-07-15
This paper investigates chaos control for the brushless DC motor (BLDCM) system by adaptive dynamic surface approach based on neural network with the minimum weights. The BLDCM system contains parameter perturbation, chaotic behavior, and uncertainty. With the help of radial basis function (RBF) neural network to approximate the unknown nonlinear functions, the adaptive law is established to overcome uncertainty of the control gain. By introducing the RBF neural network and adaptive technology into the dynamic surface control design, a robust chaos control scheme is developed. It is proved that the proposed control approach can guarantee that all signals in the closed-loop system are globally uniformly bounded, and the tracking error converges to a small neighborhood of the origin. Simulation results are provided to show that the proposed approach works well in suppressing chaos and parameter perturbation.
Directory of Open Access Journals (Sweden)
Bangcheng Han
2013-01-01
Full Text Available We firstly report on an investigation into the unbalanced magnetic pull (UMP effect on the static stiffness models of radial active magnetic bearing (RAMB in brushless DC motor (BDCM in no-loaded and loaded conditions using the finite element method (FEM. The influences of the UMP on the force-control current, force-position, current stiffness, and position stiffness of RAMB are clarified in BDCM with 100 kW rated power. We found the position stiffness to be more susceptible to UMP. The primary source of UMP is the permanent magnets of BDCM. In addition, the performance of RAMB is affected by the UMP ripples during motor commutation and also periodically affected by the angular position of rotor. The characteristic curves of RAMB force versus control current (or rotor position and angular position of rotor affected by the UMP are given. The method is useful in design and optimization of RAMB in magnetically suspended BDCMs.
Directory of Open Access Journals (Sweden)
Tianxun Chen
2016-01-01
Full Text Available This paper presents a computationally efficient loss prediction procedure and thermal analysis of surface-mounted brushless AC permanent magnet (PM machine considering the UDDS driving duty cycle by using a lumped parameters’ thermal model. The accurate prediction of loss and its variation with load are essential for thermal analysis. Employing finite element analysis (FEA to determine loss at every load point would be computationally intensive. Here, the finite element analysis and/or experiment based computationally efficient winding copper and iron loss and permanent magnet (PM power loss models are employed to calculate the electromagnetic loss at every operation point, respectively. Then, the lumped parameter thermal method is used to analyse the thermal behaviour of the driving PM machine. Experiments have been carried out to measure the temperature distribution in a motor prototype. The calculation and experiment results are compared and discussed.
Directory of Open Access Journals (Sweden)
Jingxiong ZHANG
2014-01-01
Full Text Available In this paper, a transient simulation model of a variable speed doubly fed brushless motor (DFBM using back-to-back converter is described. Based on analysis of rotor flux oriented vector control theory of doubly fed induction motor, the control of the currents in DFBM that produce the magnetic flux and the torque is achieved by a digital controller, the speed is regulated by a PI controller which is tuned by a genetic algorithm. According to the state equation of DFBM and the control schemes, the system simulation module is established in MATLAB/ SIMULINK. An extensive simulation study is performed to examine the control characteristics of the machine-side converter under different operation conditions in variable-speed DFBM driver system.
Tong, Chengde; Song, Zhiyi; Bai, Jingang; Liu, Jiaqi; Zheng, Ping
2017-05-01
The axial-flux magnetic-field-modulated brushless double-rotor machine (MFM-BDRM) is a possible alternative as a power-split device for hybrid electric vehicles (HEVs). However, the existence of large axial force may lead to assembly problems and rich inner air-gap harmonics could result in high PM loss and low efficiency. This paper proposes a novel axial-flux MFM-BDRM with improved PM rotor structure. 2-D analytical method to predict the magnetic-field distribution of the proposed MFM-BDRM is developed and the design procedure of the proposed machine is illustrated. The impact of key geometrical parameters on axial force and torque is investigated. To evaluate the advantage of the proposed machine, a comparison is made with a conventional one with respect to electromagnetic performances. Results show that the proposed machine is effective in reducing PM eddy loss and axial force by 60% and 35%, respectively.
Behavioral synthesis of asynchronous circuits
DEFF Research Database (Denmark)
Nielsen, Sune Fallgaard
2005-01-01
is idle. This reduces unnecessary switching activity in the individual functional units and therefore the energy consumption of the entire circuit. A collection of behavioral synthesis algorithms have been developed allowing the designer to perform time and power constrained design space exploration....... The datapath and control architecture is then expressed in the Balsa-language, and using syntax directed compilation a corresponding handshake circuit implementation (and eventually a layout) is produced....
Franchimon, Ellen F.; Hiremath, K.R.; Stoffer, Remco; Hammer, Manfred
Whispering gallery modes (WGMs) supported by open circular dielectric cavities are embedded into a 2-D hybrid coupled mode theory (HCMT) framework. The model enables convenient studies of supermode formation in composite circuits (CROWS, photonic molecules), and of their excitation by straight
Receiver Gain Modulation Circuit
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
Two-dimensional lattice gauge theories with superconducting quantum circuits.
Marcos, D; Widmer, P; Rico, E; Hafezi, M; Rabl, P; Wiese, U-J; Zoller, P
2014-12-01
A quantum simulator of [Formula: see text] lattice gauge theories can be implemented with superconducting circuits. This allows the investigation of confined and deconfined phases in quantum link models, and of valence bond solid and spin liquid phases in quantum dimer models. Fractionalized confining strings and the real-time dynamics of quantum phase transitions are accessible as well. Here we show how state-of-the-art superconducting technology allows us to simulate these phenomena in relatively small circuit lattices. By exploiting the strong non-linear couplings between quantized excitations emerging when superconducting qubits are coupled, we show how to engineer gauge invariant Hamiltonians, including ring-exchange and four-body Ising interactions. We demonstrate that, despite decoherence and disorder effects, minimal circuit instances allow us to investigate properties such as the dynamics of electric flux strings, signaling confinement in gauge invariant field theories. The experimental realization of these models in larger superconducting circuits could address open questions beyond current computational capability.
Animal-to-Animal Variability in Neuromodulation and Circuit Function.
Hamood, Albert W; Marder, Eve
2014-01-01
Each animal alive in the world is different from all other individuals, while sharing most attributes of form and function with others of the same species. Still other attributes are shared within a phylum, and still others are common to most eukaryotic organisms. All animals have mechanisms that modulate the strength of their synapses or alter the intrinsic excitability of component neurons. What animal-to-animal variability in behavior arises from differences in neuronal structure, ion channel expression, or connectivity, and what variability arises from neuromodulation of brain states? Conversely, can robust behavior be maintained despite variability in circuit components by the action of neuromodulatory inputs? These are fundamental issues relevant to all nervous systems that have been illuminated by many years of study of the small, rhythmic motor circuits found in the crustacean stomatogastric nervous system. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.
Convergence rates for arbitrary statistical moments of random quantum circuits.
Brown, Winton G; Viola, Lorenza
2010-06-25
We consider a class of random quantum circuits where at each step a gate from a universal set is applied to a random pair of qubits, and determine how quickly averages of arbitrary finite-degree polynomials in the matrix elements of the resulting unitary converge to Haar measure averages. This is accomplished by mapping the superoperator that describes t order moments on n qubits to a multilevel SU(4^{t}) Lipkin-Meshkov-Glick Hamiltonian. We show that, for arbitrary fixed t, the ground-state manifold is exactly spanned by factorized eigenstates and, under the assumption that a mean-field ansatz accurately describes the low-lying excitations, the spectral gap scales as 1/n in the thermodynamic limit. Our results imply that random quantum circuits yield an efficient implementation of ϵ approximate unitary t designs.
Noise-Reduction Circuit For Imaging Photodetectors
Ramirez, Luis J.; Pain, Bedabrata; Staller, Craig; Hickok, Roger W.
1995-01-01
Developmental correlated-triple-sampling circuit suppresses capacitor reset noise and attenuates low frequency noise in integrated-and-sampled circuits of multiplexed photodiode arrays. Noise reduction circuit part of Visible and Infrared Mapping Spectrometer (VIMS) instrument to fly aboard Cassini spacecraft to explore Saturn and its moons. Modified versions of circuit also useful for reducing noise in terrestrial photosensor instruments.
Multi-Layer E-Textile Circuits
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.
An integrator circuit in cerebellar cortex.
Maex, Reinoud; Steuber, Volker
2013-09-01
The brain builds dynamic models of the body and the outside world to predict the consequences of actions and stimuli. A well-known example is the oculomotor integrator, which anticipates the position-dependent elasticity forces acting on the eye ball by mathematically integrating over time oculomotor velocity commands. Many models of neural integration have been proposed, based on feedback excitation, lateral inhibition or intrinsic neuronal nonlinearities. We report here that a computational model of the cerebellar cortex, a structure thought to implement dynamic models, reveals a hitherto unrecognized integrator circuit. In this model, comprising Purkinje cells, molecular layer interneurons and parallel fibres, Purkinje cells were able to generate responses lasting more than 10 s, to which both neuronal and network mechanisms contributed. Activation of the somatic fast sodium current by subthreshold voltage fluctuations was able to maintain pulse-evoked graded persistent activity, whereas lateral inhibition among Purkinje cells via recurrent axon collaterals further prolonged the responses to step and sine wave stimulation. The responses of Purkinje cells decayed with a time-constant whose value depended on their baseline spike rate, with integration vanishing at low ( 30 per s). The model predicts that the apparently fast circuit of the cerebellar cortex may control the timing of slow processes without having to rely on sensory feedback. Thus, the cerebellar cortex may contain an adaptive temporal integrator, with the sensitivity of integration to the baseline spike rate offering a potential mechanism of plasticity of the response time-constant. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.
CINE: Comet INfrared Excitation
de Val-Borro, Miguel; Cordiner, Martin A.; Milam, Stefanie N.; Charnley, Steven B.
2017-08-01
CINE calculates infrared pumping efficiencies that can be applied to the most common molecules found in cometary comae such as water, hydrogen cyanide or methanol. One of the main mechanisms for molecular excitation in comets is the fluorescence by the solar radiation followed by radiative decay to the ground vibrational state. This command-line tool calculates the effective pumping rates for rotational levels in the ground vibrational state scaled by the heliocentric distance of the comet. Fluorescence coefficients are useful for modeling rotational emission lines observed in cometary spectra at sub-millimeter wavelengths. Combined with computational methods to solve the radiative transfer equations based, e.g., on the Monte Carlo algorithm, this model can retrieve production rates and rotational temperatures from the observed emission spectrum.
Balancing the excitability of M1 circuitry during movement observation without overt replication
Directory of Open Access Journals (Sweden)
Pablo eArias
2014-09-01
Full Text Available Although observation of a movement increases the excitability of the motor system of the observer, it does not induce a motor replica. What is the mechanism for replica suppression? We performed a series of experiments, involving a total of 66 healthy humans, to explore the excitability of different M1 circuits and the spinal cord during observation of simple movements. Several strategies were used. In the first and second experimental blocks, we used several delay times from movement onset to evaluate the time-course modulation of the cortico-spinal excitability (CSE, and its potential dependency on the duration of the movement observed; in order to do this single pulse transcranial magnetic stimulation (TMS over M1 was used. In subsequent experiments, at selected delay times from movement-onset, we probed the excitability of the cortico-spinal circuits using three different approaches: i electric cervicomedullary stimulation, to test spinal excitability, ii paired-pulse TMS over M1, to evaluate the cortical inhibitory-excitatory balance (short intracortical inhibition SICI and intracortical facilitation ICF and iii continuous theta-burst stimulation (cTBS, to modulate the excitability of M1cortical circuits. We observed a stereotyped response in the modulation of CSE. At 500ms after movement-onset the ICF was increased; although the most clear-cut effect was a decrease of CSE. The compensatory mechanism was not explained by changes in SICI, but by M1-intracortical circuits targeted by cTBS. Meanwhile, the spinal cord maintained the elevated level of excitability induced when expecting to observe movements, potentially useful to facilitate any required response to the movement observed.
Brushless Superconducting Generator.
1982-10-01
appreciation to many colleagues who have contributed helpful ideas and suggestions. In particular, they wish to thank H. Laquer , S. Wipf, W. Hassen- zahl and...Rev. Sci. Intr. 29, 537 (1958); Laquer , H.L., Cryogenics 3, 27 (1963); Buchheld, T., Cryogenics 4-212 (1964); Felici, N.J., Am. Phys. Paris 13, 266
Basic electric circuit theory a one-semester text
Mayergoyz, Isaak D
1996-01-01
This is the only book on the market that has been conceived and deliberately written as a one-semester text on basic electric circuit theory. As such, this book employs a novel approach to the exposition of the material in which phasors and ac steady-state analysis are introduced at the beginning. This allows one to use phasors in the discussion of transients excited by ac sources, which makes the presentation of transients more comprehensive and meaningful. Furthermore, the machinery of phasors paves the road to the introduction of transfer functions, which are then used in the analysis of tr
Nanofabrication of Plasmonic Circuits Containing Single Photon Sources
DEFF Research Database (Denmark)
Siampour, Hamidreza; Kumar, Shailesh; Bozhevolnyi, Sergey I.
2017-01-01
Nanofabrication of photonic components based on dielectric loaded surface plasmon polariton waveguides (DLSPPWs) excited by single nitrogen vacancy (NV) centers in nanodiamonds is demonstrated. DLSPPW circuits are built around NV containing nanodiamonds, which are certified to be single-photon...... emitters, using electron-beam lithography of hydrogen silsesquioxane (HSQ) resist on silver-coated silicon substrates. A propagation length of 20 ± 5 μm for the NV single-photon emission is measured with DLSPPWs. A 5-fold enhancement in the total decay rate, and 58% coupling efficiency to the DLSPPW mode...
Bioluminescent bioreporter integrated circuits (BBICs)
Simpson, Michael L.; Sayler, Gary S.; Nivens, David; Ripp, Steve; Paulus, Michael J.; Jellison, Gerald E.
1998-07-01
As the workhorse of the integrated circuit (IC) industry, the capabilities of CMOS have been expanded well beyond the original applications. The full spectrum of analog circuits from switched-capacitor filters to microwave circuit blocks, and from general-purpose operational amplifiers to sub- nanosecond analog timing circuits for nuclear physics experiments have been implemented in CMOS. This technology has also made in-roads into the growing area of monolithic sensors with devices such as active-pixel sensors and other electro-optical detection devices. While many of the processes used for MEMS fabrication are not compatible with the CMOS IC process, depositing a sensor material onto a previously fabricated CMOS circuit can create a very useful category of sensors. In this work we report a chemical sensor composed of bioluminescent bioreporters (genetically engineered bacteria) deposited onto a micro-luminometer fabricated in a standard CMOS IC process. The bioreporter used for this work emitted 490-nm light when exposed to toluene. This luminescence was detected by the micro- luminometer giving an indication of the concentration of toluene. Other bioluminescent bioreporters sensitive to explosives, mercury, and other organic chemicals and heavy metals have been reported. These could be incorporated (individually or in combination) with the micro-luminometer reported here to form a variety of chemical sensors.
Instrumentation and test gear circuits manual
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
Higher Order Parametric Excitation Modes for Spaceborne Quadrupole Mass Spectrometers
Gershman, D. J.; Block, B. P.; Rubin, M.; Benna, M.; Mahaffy, P. R.; Zurbuchen, T. H.
2011-01-01
This paper describes a technique to significantly improve upon the mass peak shape and mass resolution of spaceborne quadrupole mass spectrometers (QMSs) through higher order auxiliary excitation of the quadrupole field. Using a novel multiresonant tank circuit, additional frequency components can be used to drive modulating voltages on the quadrupole rods in a practical manner, suitable for both improved commercial applications and spaceflight instruments. Auxiliary excitation at frequencies near twice that of the fundamental quadrupole RF frequency provides the advantages of previously studied parametric excitation techniques, but with the added benefit of increased sensed excitation amplitude dynamic range and the ability to operate voltage scan lines through the center of upper stability islands. Using a field programmable gate array, the amplitudes and frequencies of all QMS signals are digitally generated and managed, providing a robust and stable voltage control system. These techniques are experimentally verified through an interface with a commercial Pfeiffer QMG422 quadrupole rod system.When operating through the center of a stability island formed from higher order auxiliary excitation, approximately 50% and 400% improvements in 1% mass resolution and peak stability were measured, respectively, when compared with traditional QMS operation. Although tested with a circular rod system, the presented techniques have the potential to improve the performance of both circular and hyperbolic rod geometry QMS sensors.
Jiaxin, Chen; Youguang, Guo; Jianguo, Zhu; College of Electromechanical Engineering, Donghua University : Faculty of Engineering, University of Technology; Faculty of Engineering, University of Technology; Faculty of Engineering, University of Technology
2007-01-01
This paper presents the performance evaluation of a high-speed surface mounted PM brushless DC motor by using an improved phase variable model. Magnetic field finite element analyses are conducted to accurately calculate the key motor parameters such as air gap flux, back electromotive force and inductance, and their dependence on rotor position and magnetic saturation. Based on the numerical magnetic field solutions, a modified incremental energy method is applied to effectively calculate th...
Smn-Deficiency Increases the Intrinsic Excitability of Motoneurons
Directory of Open Access Journals (Sweden)
Saravanan Arumugam
2017-09-01
Full Text Available During development, motoneurons experience significant changes in their size and in the number and strength of connections that they receive, which requires adaptive changes in their passive and active electrical properties. Even after reaching maturity, motoneurons continue to adjust their intrinsic excitability and synaptic activity for proper functioning of the sensorimotor circuit in accordance with physiological demands. Likewise, if some elements of the circuit become dysfunctional, the system tries to compensate for the alterations to maintain appropriate function. In Spinal Muscular Atrophy (SMA, a severe motor disease, spinal motoneurons receive less excitation from glutamatergic sensory fibers and interneurons and are electrically hyperexcitable. Currently, the origin and relationship among these alterations are not completely established. In this study, we investigated whether Survival of Motor Neuron (SMN, the ubiquitous protein defective in SMA, regulates the excitability of motoneurons before and after the establishment of the synaptic contacts. To this end, we performed patch-clamp recordings in embryonic spinal motoneurons forming complex synaptic networks in primary cultures, and in differentiated NSC-34 motoneuron-like cells in the absence of synaptic contacts. Our results show that in both conditions, Smn-deficient cells displayed lower action potential threshold, greater action potential amplitudes, and larger density of voltage-dependent sodium currents than cells with normal Smn-levels. These results indicate that Smn participates in the regulation of the cell-autonomous excitability of motoneurons at an early stage of development. This finding may contribute to a better understanding of motoneuron excitability in SMA during the development of the disease.
30 CFR 75.800 - High-voltage circuits; circuit breakers.
2010-07-01
... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 75.800... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.800 High-voltage circuits; circuit breakers. High-voltage circuits entering the underground area...
A new mode to excite a gas-discharge XeCL laser
Timmermans, J.C.M.; van Goor, F.A.; Witteman, W.J.
1993-01-01
The charge mode is a new mode to excite a discharge XeCl laser based on the dynamics of a spiker-sustainer circuit with a magnetic pulse compressor. The breakdown voltage is higher than in any other mode, due to a very fast rise time. The higher breakdown voltage provides a wider discharge and we
Subsurface excitations in a metal
DEFF Research Database (Denmark)
Ray, M. P.; Lake, R. E.; Sosolik, C. E.
2009-01-01
We investigate internal hot carrier excitations in a Au thin film bombarded by hyperthermal and low energy alkali and noble gas ions. Excitations within the thin film of a metal-oxide-semiconductor device are measured revealing that ions whose velocities fall below the classical threshold given...... by the free-electron model of a metal still excite hot carriers. Excellent agreement between these results and a nonadiabatic model that accounts for the time-varying ion-surface interaction indicates that the measured excitations are due to semilocalized electrons near the metal surface....
Dopamine Rebound-Excitation Theory: Putting Brakes on PTSD
Directory of Open Access Journals (Sweden)
Jason C Lee
2016-09-01
Full Text Available It is not uncommon for humans or animals to experience traumatic events in their lifetimes. However, the majority of individuals are resilient to long-term detrimental changes turning into anxiety and depression, such as post-traumatic stress disorder (PTSD. What underlying neural mechanism accounts for individual variability in stress resilience? Hyperactivity in fear circuits, such as the amygdalar system, is well-known to be the major pathophysiological basis for PTSD, much like a stuck accelerator. Interestingly, increasing evidence demonstrates that dopamine (DA – traditionally known for its role in motivation, reward prediction, and addiction– is also crucial in regulating fear learning and anxiety. Yet how DA neurons control stress resilience is unclear, especially given that DA neurons have multiple subtypes with distinct temporal dynamics. Here, we propose the Rebound-Excitation Theory, which posits that DA neurons’ rebound-excitation at the termination of fearful experiences serves as an important brake by providing intrinsic safety-signals to fear-processing neural circuits in a spatially and temporally controlled manner. We discuss how DA neuron rebound-excitation may be regulated by genetics and experiences, and how such physiological properties may be used as a brain-activity biomarker to predict and confer individual resilience to stress and anxiety.
Axonal Excitability in Amyotrophic Lateral Sclerosis : Axonal Excitability in ALS.
Park, Susanna B; Kiernan, Matthew C; Vucic, Steve
2017-01-01
Axonal excitability testing provides in vivo assessment of axonal ion channel function and membrane potential. Excitability techniques have provided insights into the pathophysiological mechanisms underlying the development of neurodegeneration and clinical features of amyotrophic lateral sclerosis (ALS) and related neuromuscular disorders. Specifically, abnormalities of Na+ and K+ conductances contribute to development of membrane hyperexcitability in ALS, thereby leading to symptom generation of muscle cramps and fasciculations, in addition to promoting a neurodegenerative cascade via Ca2+-mediated processes. Modulation of axonal ion channel function in ALS has resulted in significant symptomatic improvement that has been accompanied by stabilization of axonal excitability parameters. Separately, axonal ion channel dysfunction evolves with disease progression and correlates with survival, thereby serving as a potential therapeutic biomarker in ALS. The present review provides an overview of axonal excitability techniques and the physiological mechanisms underlying membrane excitability, with a focus on the role of axonal ion channel dysfunction in motor neuron disease and related neuromuscular diseases.
SMN is required for sensory-motor circuit function in Drosophila
Imlach, Wendy L.; Beck, Erin S.; Choi, Ben Jiwon; Lotti, Francesco; Pellizzoni, Livio; McCabe, Brian D.
2012-01-01
Summary Spinal muscular atrophy (SMA) is a lethal human disease characterized by motor neuron dysfunction and muscle deterioration due to depletion of the ubiquitous Survival Motor Neuron (SMN) protein. Drosophila SMN mutants have reduced muscle size and defective locomotion, motor rhythm and motor neuron neurotransmission. Unexpectedly, restoration of SMN in either muscles or motor neurons did not alter these phenotypes. Instead, SMN must be expressed in proprioceptive neurons and interneurons in the motor circuit to non-autonomously correct defects in motor neurons and muscles. SMN depletion disrupts the motor system subsequent to circuit development and can be mimicked by the inhibition of motor network function. Furthermore, increasing motor circuit excitability by genetic or pharmacological inhibition of K+ channels can correct SMN-dependent phenotypes. These results establish sensory-motor circuit dysfunction as the origin of motor system deficits in this SMA model and suggest that enhancement of motor neural network activity could ameliorate the disease. PMID:23063130
Circuit modeling for electromagnetic compatibility
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
Embedded systems circuits and programming
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
Simplified design of filter circuits
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
Programming languages for circuit design.
Pedersen, Michael; Yordanov, Boyan
2015-01-01
This chapter provides an overview of a programming language for Genetic Engineering of Cells (GEC). A GEC program specifies a genetic circuit at a high level of abstraction through constraints on otherwise unspecified DNA parts. The GEC compiler then selects parts which satisfy the constraints from a given parts database. GEC further provides more conventional programming language constructs for abstraction, e.g., through modularity. The GEC language and compiler is available through a Web tool which also provides functionality, e.g., for simulation of designed circuits.
A Digital Self Excited Loop for Accelerating Cavity Field Control
Energy Technology Data Exchange (ETDEWEB)
Curt Hovater; Trent Allison; Jean Delayen; John Musson; Tomasz Plawski
2007-06-22
We have developed a digital process that emulates an analog oscillator and ultimately a self excited loop (SEL) for field control. The SEL, in its analog form, has been used for many years for accelerating cavity field control. In essence the SEL uses the cavity as a resonant circuit -- much like a resonant (tank) circuit is used to build an oscillator. An oscillating resonant circuit can be forced to oscillate at different, but close, frequencies to resonance by applying a phase shift in the feedback path. This allows the circuit to be phased-locked to a master reference, which is crucial for multiple cavity accelerators. For phase and amplitude control the SEL must be forced to the master reference frequency, and feedback provided for in both dimensions. The novelty of this design is in the way digital signal processing (DSP) is structured to emulate an analog system. While the digital signal processing elements are not new, to our knowledge this is the first time that the digital SEL concept has been designed and demonstrated. This paper reports on the progress of the design and implementation of the digital SEL for field control of superconducting accelerating cavities.
Directory of Open Access Journals (Sweden)
Keming Zhou
2017-05-01
Full Text Available Excitation-inhibition imbalance in neural networks is widely linked to neurological and neuropsychiatric disorders. However, how genetic factors alter neuronal activity, leading to excitation-inhibition imbalance, remains unclear. Here, using the C. elegans locomotor circuit, we examine how altering neuronal activity for varying time periods affects synaptic release pattern and animal behavior. We show that while short-duration activation of excitatory cholinergic neurons elicits a reversible enhancement of presynaptic strength, persistent activation results to asynchronous and reduced cholinergic drive, inducing imbalance between endogenous excitation and inhibition. We find that the neuronal calcium sensor protein NCS-2 is required for asynchronous cholinergic release in an activity-dependent manner and dampens excitability of inhibitory neurons non-cell autonomously. The function of NCS-2 requires its Ca2+ binding and membrane association domains. These results reveal a synaptic mechanism implicating asynchronous release in regulation of excitation-inhibition balance.
From strong to ultrastrong coupling in circuit QED architectures
Energy Technology Data Exchange (ETDEWEB)
Niemczyk, Thomas
2011-08-10
The field of cavity quantum electrodynamics (cavity QED) studies the interaction between light and matter on a fundamental level: a single atom interacts with a single photon. If the atom-photon coupling is larger than any dissipative effects, the system enters the strong-coupling limit. A peculiarity of this regime is the possibility to form coherent superpositions of light and matter excitations - a kind of 'molecule' consisting of an atomic and a photonic contribution. The novel research field of circuit QED extends cavity QED concepts to solid-state based system. Here, a superconducting quantum bit is coupled to an on-chip superconducting one-dimensional waveguide resonator. Owing to the small mode-volume of the resonant cavity, the large dipole moment of the 'artificial atom' and the enormous engineering potential inherent to superconducting quantum circuits, remarkable atom-photon coupling strengths can be realized. This thesis describes the theoretical framework, the development of fabrication techniques and the implementation of experimental characterization techniques for superconducting quantum circuits for circuit QED applications. In particular, we study the interaction between superconducting flux quantum bits and high-quality coplanar waveguide resonators in the strong-coupling limit. Furthermore, we report on the first experimental realization of a circuit QED system operating in the ultrastrong-coupling regime, where the atom-photon coupling rate reaches a considerable fraction of the relevant system frequencies. In these experiments we could observe phenomena that can not be explained within the renowned Jaynes-Cummings model. (orig.)
Chemoreception and neuroplasticity in respiratory circuits.
Barnett, William H; Abdala, Ana P; Paton, Julian F R; Rybak, Ilya A; Zoccal, Daniel B; Molkov, Yaroslav I
2017-01-01
The respiratory central pattern generator must respond to chemosensory cues to maintain oxygen (O 2 ) and carbon dioxide (CO 2 ) homeostasis in the blood and tissues. To do this, sensorial cells located in the periphery and central nervous system monitor the arterial partial pressure of O 2 and CO 2 and initiate respiratory and autonomic reflex adjustments in conditions of hypoxia and hypercapnia. In conditions of chronic intermittent hypoxia (CIH), repeated peripheral chemoreceptor input mediated by the nucleus of the solitary tract induces plastic changes in respiratory circuits that alter baseline respiratory and sympathetic motor outputs and result in chemoreflex sensitization, active expiration, and arterial hypertension. Herein, we explored the hypothesis that the CIH-induced neuroplasticity primarily consists of increased excitability of pre-inspiratory/inspiratory neurons in the pre-Bötzinger complex. To evaluate this hypothesis and elucidate neural mechanisms for the emergence of active expiration and sympathetic overactivity in CIH-treated animals, we extended a previously developed computational model of the brainstem respiratory-sympathetic network to reproduce experimental data on peripheral and central chemoreflexes post-CIH. The model incorporated neuronal connections between the 2nd-order NTS neurons and peripheral chemoreceptors afferents, the respiratory pattern generator, and sympathetic neurons in the rostral ventrolateral medulla in order to capture key features of sympathetic and respiratory responses to peripheral chemoreflex stimulation. Our model identifies the potential neuronal groups recruited during peripheral chemoreflex stimulation that may be required for the development of inspiratory, expiratory and sympathetic reflex responses. Moreover, our model predicts that pre-inspiratory neurons in the pre-Bötzinger complex experience plasticity of channel expression due to excessive excitation during peripheral chemoreflex. Simulations
Increasing average power in medical ultrasonic endoscope imaging system by coded excitation
Chen, Xiaodong; Zhou, Hao; Wen, Shijie; Yu, Daoyin
2008-12-01
Medical ultrasonic endoscope is the combination of electronic endoscope and ultrasonic sensor technology. Ultrasonic endoscope sends the ultrasonic probe into coelom through biopsy channel of electronic endoscope and rotates it by a micro pre-motor, which requires that the length of ultrasonic probe is no more than 14mm and the diameter is no more than 2.2mm. As a result, the ultrasonic excitation power is very low and it is difficult to obtain a sharp image. In order to increase the energy and SNR of ultrasonic signal, we introduce coded excitation into the ultrasonic imaging system, which is widely used in radar system. Coded excitation uses a long coded pulse to drive ultrasonic transducer, which can increase the average transmitting power accordingly. In this paper, in order to avoid the overlapping between adjacent echo, we used a four-figure Barker code to drive the ultrasonic transducer, which is modulated at the operating frequency of transducer to improve the emission efficiency. The implementation of coded excitation is closely associated with the transient operating characteristic of ultrasonic transducer. In this paper, the transient operating characteristic of ultrasonic transducer excited by a shock pulse δ(t) is firstly analyzed, and then the exciting pulse generated by special ultrasonic transmitting circuit composing of MD1211 and TC6320. In the final part of the paper, we designed an experiment to validate the coded excitation with transducer operating at 5MHz and a glass filled with ultrasonic coupling liquid as the object. Driven by a FPGA, the ultrasonic transmitting circuit output a four-figure Barker excitation pulse modulated at 5MHz, +/-20 voltage and is consistent with the transient operating characteristic of ultrasonic transducer after matched by matching circuit. The reflected echo from glass possesses coded character, which is identical with the simulating result by Matlab. Furthermore, the signal's amplitude is higher.
Striatal cholinergic interneuron regulation and circuit effects
Directory of Open Access Journals (Sweden)
Sean Austin Lim
2014-10-01
Full Text Available The striatum plays a central role in motor control and motor learning. Appropriate responses to environmental stimuli, including pursuit of reward or avoidance of aversive experience all require functional striatal circuits. These pathways integrate synaptic inputs from limbic and cortical regions including sensory, motor and motivational information to ultimately connect intention to action. Although many neurotransmitters participate in striatal circuitry, one critically important player is acetylcholine (ACh. Relative to other brain areas, the striatum contains exceptionally high levels of ACh, the enzymes that catalyze its synthesis and breakdown, as well as both nicotinic and muscarinic receptor types that mediate its postsynaptic effects. The principal source of striatal ACh is the cholinergic interneuron (ChI, which comprises only about 1-2% of all striatal cells yet sends dense arbors of projections throughout the striatum. This review summarizes recent advances in our understanding of the factors affecting the excitability of these neurons through acute effects and long term changes in their synaptic inputs. In addition, we discuss the physiological effects of ACh in the striatum, and how changes in ACh levels may contribute to disease states during striatal dysfunction.
Topological excitations in magnetic materials
Energy Technology Data Exchange (ETDEWEB)
Bazeia, D., E-mail: bazeia@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Doria, M.M. [Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil); Dipartimento di Fisica, Università di Camerino, I-62032 Camerino (Italy); Rodrigues, E.I.B. [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil)
2016-05-20
In this work we propose a new route to describe topological excitations in magnetic systems through a single real scalar field. We show here that spherically symmetric structures in two spatial dimensions, which map helical excitations in magnetic materials, admit this formulation and can be used to model skyrmion-like structures in magnetic materials.
Integrated Circuit Stellar Magnitude Simulator
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)
A Low Noise Electronic Circuit
Annema, Anne J.; Leenaerts, Dominicus M.W.; de Vreede, Petrus W.H.
2002-01-01
An electronic circuit, which can be used as a Low Noise Amplifier (LNA), comprises two complementary Field Effect Transistors (M1, M2; M5, M6), each having a gate, a source and a drain. The gates are connected together as a common input terminal, and the drains are connected together as a
Invention of the Integrated Circuit
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 11. Invention of the Integrated Circuit. Jack S Kilby. Classics Volume 17 Issue 11 November 2012 pp 1100-1115. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/017/11/1100-1115 ...
Development of CMOS integrated circuits
Bertino, F.; Feller, A.; Greenhouse, J.; Lombardi, T.; Merriam, A.; Noto, R.; Ozga, S.; Pryor, R.; Ramondetta, P.; Smith, A.
1979-01-01
Report documents life cycles of two custom CMOS integrated circuits: (1) 4-bit multiplexed register with shift left and shift right capabilities, and (2) dual 4-bit registers. Cycles described include conception as logic diagrams through design, fabrication, testing, and delivery.
Data assimilation with Chua's circuit
Indian Academy of Sciences (India)
noise and observational frequency, using both simulated observations and data obtained from an experimental realization of a commonly used low-dimensional dynamical system, namely, Chua circuit, in both the periodic as well as the chaotic regime. Keywords. Synchronization; ensemble Kalman filter; data assimilation.
Circuit design for RF transceivers
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.
Parallel circuit simulation on supercomputers
Energy Technology Data Exchange (ETDEWEB)
Saleh, R.A.; Gallivan, K.A. (Illinois Univ., Urbana, IL (USA). Center for Supercomputing Research and Development); Chang, M.C. (Texas Instruments, Inc., Dallas, TX (USA)); Hajj, I.N.; Trick, T.N. (Illinois Univ., Urbana, IL (USA). Coordinated Science Lab.); Smart, D. (Semiconductor Div., Analog Devices, Wilmington, MA (US))
1989-12-01
Circuit simulation is a very time-consuming and numerically intensive application, especially when the problem size is large as in the case of VLSI circuits. To improve the performance of circuit simulators without sacrificing accuracy, a variety of parallel processing algorithms have been investigated due to the recent availability of a number of commercial multiprocessor machines. In this paper, research in the field of parallel circuit simulation is surveyed and the ongoing research in this area at the University of Illinois is described. Both standard and relaxation-based approaches are considered. In particular, the forms of parallelism available within the direct method approach, used in programs such as SPICE2 and SLATE, and within the relaxation-based approaches, such as waveform relaxation, iterated timing analysis, and waveform-relaxation-Newton, are described. The specific implementation issues addressed here are primarily related to general-purpose multiprocessors with a shared-memory architecture having a limited number of processors, although many of the comments also apply to a number of other architectures.
Designing analog circuits in CMOS
Annema, Anne J.; Nauta, Bram; van Langevelde, Ronald; Tuinhout, Hans
2004-01-01
The evolution in CMOS technology dictated by Moore's Law is clearly beneficial for designers of digital circuits, but it presents difficult challenges, such as lowered nominal supply voltages, for their peers in the analog world who want to keep pace with this rapid progression. This article
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....
Advanced circuit simulation using Multisim workbench
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
Digital circuit boards mach 1 GHz
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
Stibitz, G R; McCann, F V
1974-02-01
The impedance measured in a strip of heart tissue from the moth Hyalophora cecropia is fitted by circuit models of several configurations. The circuits include: (a) a single R-C circuit (b) a double R-C circuit (c) terminated transmission lines, and (d) a pattern of cells with cell-to-cell transmission paths. The last of these is found to give the best fit. Calculation of the model impedances and optimization of element values are performed by a computer. The possibility that the mechanism of cell-to-cell transmission may be capacitative rather than conductive is explored using values of capacitance derived from the circuit models to calculate the effect of capacitative coupling alone on signal transmission. The calculations show that sufficient voltage can be transmitted from the excited cell to an adjacent cell to effect excitation.
Growth mechanism and magnon excitation in NiO nanowalls
Directory of Open Access Journals (Sweden)
Yang Chun
2011-01-01
Full Text Available Abstract The nanosized effects of short-range multimagnon excitation behavior and short-circuit diffusion in NiO nanowalls synthesized using the Ni grid thermal treatment method were observed. The energy dispersive spectroscopy mapping technique was used to characterize the growth mechanism, and confocal Raman scattering was used to probe the antiferromagnetic exchange energy J 2 between next-nearest-neighboring Ni ions in NiO nanowalls at various growth temperatures below the Neel temperature. This study shows that short spin correlation leads to an exponential dependence of the growth temperatures and the existence of nickel vacancies during the magnon excitation. Four-magnon configurations were determined from the scattering factor, revealing a lowest state and monotonic change with the growth temperature. PACS: 75.47.Lx; 61.82.Rx; 75.50.Tt; 74.25.nd; 72.10.Di
One Photon Can Simultaneously Excite Two or More Atoms.
Garziano, Luigi; Macrì, Vincenzo; Stassi, Roberto; Di Stefano, Omar; Nori, Franco; Savasta, Salvatore
2016-07-22
We consider two separate atoms interacting with a single-mode optical or microwave resonator. When the frequency of the resonator field is twice the atomic transition frequency, we show that there exists a resonant coupling between one photon and two atoms, via intermediate virtual states connected by counterrotating processes. If the resonator is prepared in its one-photon state, the photon can be jointly absorbed by the two atoms in their ground state which will both reach their excited state with a probability close to one. Like ordinary quantum Rabi oscillations, this process is coherent and reversible, so that two atoms in their excited state will undergo a downward transition jointly emitting a single cavity photon. This joint absorption and emission process can also occur with three atoms. The parameters used to investigate this process correspond to experimentally demonstrated values in circuit quantum electrodynamics systems.
Steady-state time-periodic finite element analysis of a brushless DC motor drive considering motion
Directory of Open Access Journals (Sweden)
Jagieła Mariusz
2015-09-01
Full Text Available This paper aims at providing a framework for comprehensive steady-state time-domain analysis of rotating machines considering motion. The steady-state waveforms of electromagnetic and circuit quantities are computed via iterative solution of the nonlinear field-circuit-and-motion problem with constraints of time periodicity. The cases with forced speed and forced load torque are considered. A comparison of execution times with a conventional time-stepping transient model is carried out for two different machines. The numerical stability of a time-periodic model with forced speed is shown to be worse than that of traditional transient time-stepping one, although the model converges within a reasonable number of iterations. This is not the case if forced load via equation of mechanical balance is accounted for. To ensure convergence of the iterative process the physical equation of motion is replaced by the fixed-point equation. In this way the model delivers time-periodic solutions regarding not only the electromagnetic quantities but also the rotational speed.
Fabric circuits and method of manufacturing fabric circuits
Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Scully, Robert C. (Inventor); Trevino, Robert C. (Inventor); Lin, Greg Y. (Inventor); Fink, Patrick W. (Inventor)
2011-01-01
A flexible, fabric-based circuit comprises a non-conductive flexible layer of fabric and a conductive flexible layer of fabric adjacent thereto. A non-conductive thread, an adhesive, and/or other means may be used for attaching the conductive layer to the non-conductive layer. In some embodiments, the layers are attached by a computer-driven embroidery machine at pre-determined portions or locations in accordance with a pre-determined attachment layout before automated cutting. In some other embodiments, an automated milling machine or a computer-driven laser using a pre-designed circuit trace as a template cuts the conductive layer so as to separate an undesired portion of the conductive layer from a desired portion of the conductive layer. Additional layers of conductive fabric may be attached in some embodiments to form a multi-layer construct.
IMPROVING THE RELIABILITY OF THE POWER CIRCUIT OF THE ELECTRIC TRAINS ЕР2Т AND ЕПЛ2Т
Directory of Open Access Journals (Sweden)
N. H. Visin
2010-02-01
Full Text Available The transitional processes in shunt circuit of traction engines, which armatures and excitation windings are connected in non-conducting direction as to the flowing power current, are considered in this paper. The changes in the control circuits of braking switch and in the shunt power circuit of traction engines with additional mounting a resistor of 0.5 Ohm are proposed. All this modernization will allow increasing greatly the operation reliability of power circuit of ЭР2Т and ЕПЛ2Т electric locomotives during their service life.
Analog Nonvolatile Computer Memory Circuits
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
Energy Technology Data Exchange (ETDEWEB)
Lopez-Arrietea, M. G.; Solis, M. A.; De Llano, M. [Universidad Nacional Autonoma de Mexico, Mexico, D.F (Mexico)
2001-02-01
Excited cooper pairs formed in a many-fermion system are those with nonzero total center-of mass momentum (CMM). They are normally neglected in the standard Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity for being too few compared with zero CMM pairs. However, a Bose-Einstein condensation picture requires both zero and nonzero CMM pairs. Assuming a BCS model interaction between fermions we determine the populations for all CMM values of Cooper pairs by actually calculating the number of nonzero-CMM pairs relative to that of zero-CMM ones in both 2D and 3D. Although this ratio decreases rapidly with CMM, the number of Cooper pairs for any specific CMM less than the maximum (or breakup of the pair) momentum turns out to be typically larger than about 95% of those with zero-CMM at zero temperature T. Even at T {approx}100 K this fraction en 2D is still as large as about 70% for typical quasi-2D cuprate superconductor parameters. [Spanish] Los pares de cooper excitados formados en un sistema de muchos electrones, son aquellos con momentos de centro de masa (CMM) diferente de cero. Normalmente estos no son tomados en cuenta en la teoria estandar de la superconductividad de Bardeen-Cooper-Schrieffer (BCS) al suponer que su numero es muy pequeno comparados con los pares de centro de masa igual a cero. Sin embargo, un esquema de condensacion Bose-Einstein requiere de ambos pares, con CMM cero y diferente de cero. Asumiendo una interaccion modelo BCS entre los fermiones, determinamos la poblacion de pares cooper con cada uno de todos los posibles valores del CMM calculando el numero de pares con momentos de centro de masa diferente de cero relativo a los pares de CMM igual a cero, en 2D y 3D. Aunque esta razon decrece rapidamente con el CMM, el numero de pares de cooper para cualquier CMM especifico menor que el momento maximo (o rompimiento de par) es tipicamente mas grande que el 95% de aquellos con CMM cero. Aun a T {approx}100 K esta fraccion en 2D es
Driver circuit for solid state light sources
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.
Developing a Domain Model for Relay Circuits
DEFF Research Database (Denmark)
Haxthausen, Anne Elisabeth
2009-01-01
In this paper we stepwise develop a domain model for relay circuits as used in railway control systems. First we provide an abstract, property-oriented model of networks consisting of components that can be glued together with connectors. This model is strongly inspired by a network model...... for railways madeby Bjørner et.al., however our model is more general: the components can be of any kind and can later be refined to e.g. railway components or circuit components. Then we show how the abstract network model can be refined into an explicit model for relay circuits. The circuit model describes...... the statics as well as the dynamics of relay circuits, i.e. how a relay circuit can be composed legally from electrical components as well as how the components may change state over time. Finally the circuit model is transformed into an executable model, and we show how a concrete circuit can be defined...
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...
Uniform excitations in magnetic nanoparticles
Directory of Open Access Journals (Sweden)
Steen Mørup
2010-11-01
Full Text Available We present a short review of the magnetic excitations in nanoparticles below the superparamagnetic blocking temperature. In this temperature regime, the magnetic dynamics in nanoparticles is dominated by uniform excitations, and this leads to a linear temperature dependence of the magnetization and the magnetic hyperfine field, in contrast to the Bloch T3/2 law in bulk materials. The temperature dependence of the average magnetization is conveniently studied by Mössbauer spectroscopy. The energy of the uniform excitations of magnetic nanoparticles can be studied by inelastic neutron scattering.
Uniform excitations in magnetic nanoparticles
DEFF Research Database (Denmark)
Mørup, Steen; Frandsen, Cathrine; Hansen, Mikkel Fougt
2010-01-01
We present a short review of the magnetic excitations in nanoparticles below the superparamagnetic blocking temperature. In this temperature regime, the magnetic dynamics in nanoparticles is dominated by uniform excitations, and this leads to a linear temperature dependence of the magnetization...... and the magnetic hyperfine field, in contrast to the Bloch T3/2 law in bulk materials. The temperature dependence of the average magnetization is conveniently studied by Mössbauer spectroscopy. The energy of the uniform excitations of magnetic nanoparticles can be studied by inelastic neutron scattering....
Brain-machine interface circuits and systems
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.
Circuit Tolerance Design Using Belief Rule Base
Xiao-Bin Xu; Zheng Liu; Yu-Wang Chen; Dong-Ling Xu; Cheng-Lin Wen
2015-01-01
A belief rule-based (BRB) system provides a generic nonlinear modeling and inference mechanism. It is capable of modeling complex causal relationships by utilizing both quantitative information and qualitative knowledge. In this paper, a BRB system is firstly developed to model the highly nonlinear relationship between circuit component parameters and the performance of the circuit by utilizing available knowledge from circuit simulations and circuit designers. By using rule inference in the ...
Influence of an inner short-circuit on the behaviour of the superconducting magnet
Energy Technology Data Exchange (ETDEWEB)
Zizek, F. (Skoda k.p., Plzen (Czechoslovakia))
1984-01-01
On exciting one of the superconducting quadrupole magnets, voltage pulses were observed on the winding outlets. Over a certain current level the pulses disappeared and a quench of the magnet was registered. A subsequent analysis proved that phenomenon was caused by short-circuiting of the turns inside one of the quadrupole coils. The voltage pulses were caused by repeated quenches of the short-circuited part of the winding. The above effect did not appear until a certain rate of rise of the current was attained.
Superfluid-Mott-insulator transition in superconducting circuits with weak anharmonicity
Zheng, Li-Li; Li, Ke-Min; Lü, Xin-You; Wu, Ying
2017-11-01
We investigate theoretically the ground-state property of a two-dimensional array of superconducting circuits including the on-site superconducting qubits (SQs) with weak anharmonicity. In particular, we analyze the influence of this anharmonicity on the Mott-insulator to superfluid quantum phase transition. The complete ground-state phase diagrams are presented under the mean-field approximation. Interestingly, the anharmonicity of SQs affects the Mott lobes enormously, and the single excitation Mott lobe disappears when the anharmonicity becomes zero. Our results can be used to guide the implementations of quantum simulations using the superconducting circuits, which have nice integrating and flexibility.
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. Copyright © 2015 The Authors. Published by
Nanoelectronic circuit design and test
Simsir, Muzaffer Orkun
Controlling power consumption in CMOS integrated circuits (ICs) during normal mode of operation is becoming one of the limiting factors to further scaling. In addition, it is a well known fact that during testing of a complex IC, power consumption can far exceed the values reached during its normal operation. High power consumption, combined with limited cooling support, leads to overheating of ICs. This can cause permanent damage to the chip or can invalidate test results due to the fact that extreme temperature variations lead to changes in path delays. Therefore, even good chips can fail the test. For these reasons, thermal problems during test need to be identified to prevent the loss of yield in CMOS ICs. In this thesis, we propose a methodology for thermally characterizing circuits under test. Using this methodology, it is possible to simulate the thermal profiles of the chips during test and prevent possible yield loss because of thermal problems. In addition to the problems associated with power and temperature, a more important barrier is the scaling limitations of the CMOS technology. It has been predicted that in next decade, it will not be possible to scale it further. In the near future, rather than a transition to a completely new technology, extensions to CMOS seem to be more realistic. Double-gate CMOS technology is one of the most promising alternatives that offers a simple extension to CMOS. The transistors of this technology are formed by adding a second gate across the conventional CMOS transistor gate. Designing circuits using this technology has attracted a lot of attention. However, as circuit design methods mature, there is a need to identify how these circuits can be tested. From a circuit testing viewpoint, it is unclear if CMOS fault models are comprehensive enough to model all defects in double-gate CMOS circuits. Therefore, fault models of this technology need to be defined to enable manufacturing-time testing. In this thesis, we
CMOS digital integrated circuits a first course
Hawkins, Charles; Zarkesh-Ha, Payman
2016-01-01
This book teaches the fundamentals of modern CMOS technology and covers equal treatment to both types of MOSFET transistors that make up computer circuits; power properties of logic circuits; physical and electrical properties of metals; introduction of timing circuit electronics and introduction of layout; real-world examples and problem sets.
On dominating and spanning circuits in graphs
Veldman, H.J.
1994-01-01
An eulerian subgraph of a graph is called a circuit. As shown by Harary and Nash-Williams, the existence of a Hamilton cycle in the line graph L(G) of a graph G is equivalent to the existence of a dominating circuit in G, i.e., a circuit such that every edge of G is incident with a vertex of the
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....
49 CFR 236.721 - Circuit, control.
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. ...
Piezo pump and pressurized circuit provided therewith
Van Es, Johannes; Wits, Wessel Willems
2015-01-01
A piezo pump for use in a pressurized circuit includes a pump chamber with an inlet provided with a one way inlet valve, for connection to a feeding line of the pressurized circuit and an outlet provided with a one way outlet valve, for connection to a discharge line of the pressurized circuit and a
Finding All Elementary Circuits Exploiting Transconductance
Klumperink, Eric A.M.; Bruccoleri, F.; Nauta, Bram
Commonly used elementary circuits like single transistor amplifier stages, the differential pair and current mirror basically exploit the transconductance of transistors. This paper aims at finding ALL elementary transconductance based circuits. For this purpose, all graphs of two-port circuits with
Advanced Microwave Circuits and Systems
DEFF Research Database (Denmark)
as sufficient gain in a wide frequency range of operation, which is very difficult to achieve. Most circuits demonstrated are not stable across the frequency band, which makes these amplifiers prone to self-oscillations and therefore limit their applicability. The trade-off between noise figure, gain, linearity......This book is based on recent research work conducted by the authors dealing with the design and development of active and passive microwave components, integrated circuits and systems. It is divided into seven parts. In the first part comprising the first two chapters, alternative concepts...... and equations for multiport network analysis and characterization are provided. A thru-only de-embedding technique for accurate on-wafer characterization is introduced. The second part of the book corresponds to the analysis and design of ultra-wideband low-noise amplifiers (LNA). The LNA is the most critical...
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...
Foundations for microstrip circuit design
Edwards, Terry
2016-01-01
Building on the success of the previous three editions, Foundations for Microstrip Circuit Design offers extensive new, updated and revised material based upon the latest research. Strongly design-oriented, this fourth edition provides the reader with a fundamental understanding of this fast expanding field making it a definitive source for professional engineers and researchers and an indispensable reference for senior students in electronic engineering. Topics new to this edition: microwave substrates, multilayer transmission line structures, modern EM tools and techniques, microstrip and planar transmision line design, transmission line theory, substrates for planar transmission lines, Vias, wirebonds, 3D integrated interposer structures, computer-aided design, microstrip and power-dependent effects, circuit models, microwave network analysis, microstrip passive elements, and slotline design fundamentals.
Quantum information with superconducting circuits
Huard, Benjamin
2014-01-01
Ce mémoire présente ma contribution à l'avènement des circuits supraconducteurs comme composant de base des systèmes d'information quantique. Les variables macroscopiques des circuits électriques, telles que la tension et le courant, obéissent aux lois de la mécanique quantique tant qu'elles sont suffisamment découplées de leur environnement. Depuis que les premiers qubits supraconducteurs ont été réalisés il y a 15 ans, leurs temps de cohérence ont augmenté de 5 ordres de gra...
Delta connected resonant snubber circuit
Lai, J.S.; Peng, F.Z.; Young, R.W. Sr.; Ott, G.W. Jr.
1998-01-20
A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter. 36 figs.
Smart Circuit Breaker Communication Infrastructure
Directory of Open Access Journals (Sweden)
Octavian Mihai MACHIDON
2017-11-01
Full Text Available The expansion of the Internet of Things has fostered the development of smart technologies in fields such as power transmission and distribution systems (as is the Smart Grid and also in regard to home automation (the Smart Home concept. This paper addresses the network communication infrastructure for a Smart Circuit Breaker system, a novel application at the edge of the two afore-mentioned systems (Smart Grid and Smart Home. Such a communication interface has high requirements from functionality, performance and security point of views, given the large amount of distributed connected elements and the real-time information transmission and system management. The paper describes the design and implementation of the data server, Web interface and the embedded networking capabilities of the smart circuit breakers, underlining the protocols and communication technologies used.
Indirect excitation of ultrafast demagnetization
National Research Council Canada - National Science Library
Vodungbo, B; Tudu, B; Perron, J; Delaunay, R; Müller, L; Berntsen, M.H; Grübel, G; Malinowski, G; Weier, C; Gautier, J; Lambert, G; Zeitoun, P; Gutt, C; Jal, E; Reid, A.H; Granitzka, P.W; Jaouen, N; Dakovski, G.L; Moeller, S; Minitti, M.P; Mitra, A; Carron, S; Pfau, B; von Korff Schmising, C; Schneider, M; Eisebitt, S; Lüning, J
2016-01-01
.... Upon excitation with an intense femtosecond-short IR laser pulse, the film exhibits the classical ultrafast demagnetization phenomenon although only a negligible number of IR photons penetrate the aluminum layer...
Transport waves as crystal excitations
Cepellotti, Andrea; Marzari, Nicola
2017-09-01
We introduce the concept of transport waves by showing that the linearized Boltzmann transport equation admits excitations in the form of waves that have well-defined dispersion relations and decay times. Crucially, these waves do not represent single-particle excitations, but are collective excitations of the equilibrium distribution functions. We study in detail the case of thermal transport, where relaxons are found in the long-wavelength limit, and second sound is reinterpreted as the excitation of one or several temperature waves at finite frequencies. Graphene is studied numerically, finding decay times of the order of microseconds. The derivation, obtained by a spectral representation of the Boltzmann equation, holds in principle for any crystal or semiclassical transport theory and is particularly relevant when transport takes place in the hydrodynamic regime.
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.
Three-Dimensional Circuit Layouts.
1984-06-01
the models of VLSI layout theory renders the vertices of our circuits as unit-side squares or cubes . 4. Our method of extending the two-dimensional...model assumes isometry in all 4$ dimensions: a unit of height is eqivalent to a unit of width. It is worthwhile placing these assumptions in perspective...2,13]. 4. Aside from clerical simplification, the isometry assumption acknowledges the potential problem of cross-talk between parallel runs of wire
49 CFR 236.5 - Design of control circuits on closed circuit principle.
2010-10-01
... shall be designed on the closed circuit principle, except circuits for roadway equipment of intermittent... 49 Transportation 4 2010-10-01 2010-10-01 false Design of control circuits on closed circuit principle. 236.5 Section 236.5 Transportation Other Regulations Relating to Transportation (Continued...
Indirect excitation of ultrafast demagnetization
Boris Vodungbo; Bahrati Tudu; Jonathan Perron; Renaud Delaunay; Leonard Müller; Berntsen, Magnus H.; Gerhard Grübel; Grégory Malinowski; Christian Weier; Julien Gautier; Guillaume Lambert; Philippe Zeitoun; Christian Gutt; Emmanuelle Jal; Reid, Alexander H.
2016-01-01
Does the excitation of ultrafast magnetization require direct interaction between the photons of the optical pump pulse and the magnetic layer? Here, we demonstrate unambiguously that this is not the case. For this we have studied the magnetization dynamics of a ferromagnetic cobalt/palladium multilayer capped by an IR-opaque aluminum layer. Upon excitation with an intense femtosecond-short IR laser pulse, the film exhibits the classical ultrafast demagnetization phenomenon although only a ne...
Stochastic Hierarchical Systems: Excitable Dynamics
Leonhardt, Helmar; Zaks, Michael A.; Falcke, Martin; Schimansky-Geier, Lutz
2008-01-01
We present a discrete model of stochastic excitability by a low-dimensional set of delayed integral equations governing the probability in the rest state, the excited state, and the refractory state. The process is a random walk with discrete states and nonexponential waiting time distributions, which lead to the incorporation of memory kernels in the integral equations. We extend the equations of a single unit to the system of equations for an ensemble of globally coupled oscillators, derive...
Autowaves in moving excitable media
Directory of Open Access Journals (Sweden)
V.A.Davydov
2004-01-01
Full Text Available Within the framework of kinematic theory of autowaves we suggest a method for analytic description of stationary autowave structures appearing at the boundary between the moving and fixed excitable media. The front breakdown phenomenon is predicted for such structures. Autowave refraction and, particulary, one-side "total reflection" at the boundary is considered. The obtained analytical results are confirmed by computer simulations. Prospects of the proposed method for further studies of autowave dynamics in the moving excitable media are discussed.
Have Gluonic Excitations Been Found?
Page, Philip R.
1996-01-01
New experimental information on the non-exotic J^PC = 0^-+ isovector seen at 1.8 GeV by VES yields convincing evidence of its excited gluonic (hybrid) nature when a critical study of alternative quarkonium assignments is made in the context of ^3 P_0 decay by flux-tube breaking. Production of this gluonic excitation via meson exchange is promising, although its two photon production vanishes.
Morita, Kenji; Jitsev, Jenia; Morrison, Abigail
2016-09-15
Value-based action selection has been suggested to be realized in the corticostriatal local circuits through competition among neural populations. In this article, we review theoretical and experimental studies that have constructed and verified this notion, and provide new perspectives on how the local-circuit selection mechanisms implement reinforcement learning (RL) algorithms and computations beyond them. The striatal neurons are mostly inhibitory, and lateral inhibition among them has been classically proposed to realize "Winner-Take-All (WTA)" selection of the maximum-valued action (i.e., 'max' operation). Although this view has been challenged by the revealed weakness, sparseness, and asymmetry of lateral inhibition, which suggest more complex dynamics, WTA-like competition could still occur on short time scales. Unlike the striatal circuit, the cortical circuit contains recurrent excitation, which may enable retention or temporal integration of information and probabilistic "soft-max" selection. The striatal "max" circuit and the cortical "soft-max" circuit might co-implement an RL algorithm called Q-learning; the cortical circuit might also similarly serve for other algorithms such as SARSA. In these implementations, the cortical circuit presumably sustains activity representing the executed action, which negatively impacts dopamine neurons so that they can calculate reward-prediction-error. Regarding the suggested more complex dynamics of striatal, as well as cortical, circuits on long time scales, which could be viewed as a sequence of short WTA fragments, computational roles remain open: such a sequence might represent (1) sequential state-action-state transitions, constituting replay or simulation of the internal model, (2) a single state/action by the whole trajectory, or (3) probabilistic sampling of state/action. Copyright © 2016. Published by Elsevier B.V.
Energy Technology Data Exchange (ETDEWEB)
Alexander, Gerald C.; Spee, Rene; Wallace, Alan K.
1993-12-31
Since the inception of the BDFM development program in 1989, the value of BDFM technology has become apparent. The BDFM provides for adjustable speed, synchronous operation while keeping costs associated with the required power conversion equipment lower than in competing technologies. This provides for an advantage in initial as well as maintenance expenses over conventional drive system. Thus, the BDFM enables energy efficient, adjustable speed process control for applications where established drive technology has not been able to deliver satisfactory returns on investment. At the same time, the BDFM challenges conventional drive technologies in established markets by providing for improved performance at lower cost. BDFM converter rating is kept at a minimum, which significantly improves power quality at the utility interface over competing power conversion equipment. In summary, BDFM technology can be expected to provide significant benefits to utilities as well as their customers. This report discusses technical research and development activities related to Phase 3 of the Brushless Doubly-Fed Machine System Development Program, including work made possible by supplemental funds for laboratory improvement and prototype construction. Market research for the BDFM was provided by the College of Business at Oregon State University; market study results will be discussed in a separate report.
Bravin, E; Sosa, A
2014-01-01
This report summarizes the results of a series of tests performed on the prototype HIE-ISOLDE diagnostic box (HIE-DB) regarding the vibrations and drifts in the transverse position of the scanning blade while moving in and out of beam path in the HIE-ISOLDE short box prototype. To monitor the transverse position of the blade, a series of 0.1 mm diameter holes were drilled on it and their positions were tracked with an optical system. The linear motion actuator was acquired from UHV design (model LSM38-150-SS), and it was adapted to be driven by a brushless EC motor from MAXON. The speed of the scanning blade during the tests was 10 mm/s. The transverse movement of the slit in the direction perpendicular to the movement was lower than 40 m, and is dominated by the displacement of the contact point of the applied force on the lead-screw. An offset on the slit position was observed while changing the direction of movement of the blade, its amplitude being of the order of 30 m. The amplitudes of the displacements...
Ozgenel, Mehmet Cihat; Bal, Gungor; Uygun, Durmus
2017-03-01
This study presents a precise speed control method for Brushless Direct Current (BLDC) Motors using an electronic tachogenerator (ETg) instead of an electro-mechanical tachogenerator. Most commonly used three-phase BLDC motors have three position sensors for rotor position data to provide commutation among stator windings. Aforementioned position sensors are usually Hall-effect sensors delivering binary-high and binary-low data as long as the motor rotates. These binary sets from three Hall-effect sensors can be used as an analogue rotor speed signal for closed loop applications. Each position sensor signal is apart from 120 electrical degrees. By using an electronic circuitry, a combination of position sensor signals is converted to the analogue signal providing an input to a PI speed controller. To implement this, a frequency to voltage converter has been used in this study. Then, the analogue speed signal has been evaluated as rotor speed data in comparison with the reference speed. So, an ETg system has been successfully achieved in place of an electro-mechanical tachogenerator for BLDC motor speed control. The proposed ETg has been tested under various speed conditions on an experimental setup. Employed tests and obtained results show that the proposed low-cost speed feedback sub-system can be effectively used in BLDC motor drive systems. Through the proved method and designed sub-system, a new motor controller chip with a speed feedback capability has been aimed.
Mousa, Mohamed G; Allam, S M; Rashad, Essam M
2018-01-01
This paper proposes an advanced strategy to synchronize the wind-driven Brushless Doubly-Fed Reluctance Generator (BDFRG) to the grid-side terminals. The proposed strategy depends mainly upon determining the electrical angle of the grid voltage, θ v and using the same transformation matrix of both the power winding and grid sides to ensure that the generated power-winding voltage has the same phase-sequence of the grid-side voltage. On the other hand, the paper proposes a vector-control (power-winding flux orientation) technique for maximum wind-power extraction under two schemes summarized as; unity power-factor operation and minimum converter-current. Moreover, a soft-starting method is suggested to avoid the employed converter over-current. The first control scheme is achieved by adjusting the command power-winding reactive power at zero for a unity power-factor operation. However, the second scheme depends on setting the command d-axis control-winding current at zero to maximize the ratio of the generator electromagnetic-torque per the converter current. This enables the system to get a certain command torque under minimum converter current. A sample of the obtained simulation and experimental results is presented to check the effectiveness of the proposed control strategies. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Chengde Tong
2017-09-01
Full Text Available In this paper, a novel sensorless control strategy based on the estimation of line back electro-motive force (BEMF is proposed. According to the phase relationship between the ideal commutation points of the brushless direct current motor (BLDCM and the zero-crossing points (ZCPs of the line BEMF, the calculation formula of line BEMF is simplified properly and the commutation rule for different positions of the rotor is presented. The estimation error of line BEMF caused by the freewheeling current of silent phase is analyzed, and the solution is given. With the phase shift of the low-pass filter considered, a compensation method using “60°-α” and “120°-α” is studied in this paper to eliminate the error. Finally, the simulation and experimental results show that the rotor-position-detection error is reduced effectively and the motor driven by the accurate commutation signal can work well at low and high speed.
Electron-excited molecule interactions
Energy Technology Data Exchange (ETDEWEB)
Christophorou, L.G. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA). Dept. of Physics)
1991-01-01
In this paper the limited but significant knowledge to date on electron scattering from vibrationally/rotationally excited molecules and electron scattering from and electron impact ionization of electronically excited molecules is briefly summarized and discussed. The profound effects of the internal energy content of a molecule on its electron attachment properties are highlighted focusing in particular on electron attachment to vibrationally/rotationally and to electronically excited molecules. The limited knowledge to date on electron-excited molecule interactions clearly shows that the cross sections for certain electron-molecule collision processes can be very different from those involving ground state molecules. For example, optically enhanced electron attachment studies have shown that electron attachment to electronically excited molecules can occur with cross sections 10{sup 6} to 10{sup 7} times larger compared to ground state molecules. The study of electron-excited molecule interactions offers many experimental and theoretical challenges and opportunities and is both of fundamental and technological significance. 54 refs., 15 figs.
Ultra-low power integrated circuit design circuits, systems, and applications
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.
Design of analog integrated circuits and systems
Laker, Kenneth R
1994-01-01
This text is designed for senior or graduate level courses in analog integrated circuits or design of analog integrated circuits. This book combines consideration of CMOS and bipolar circuits into a unified treatment. Also included are CMOS-bipolar circuits made possible by BiCMOS technology. The text progresses from MOS and bipolar device modelling to simple one and two transistor building block circuits. The final two chapters present a unified coverage of sample-data and continuous-time signal processing systems.
CMOS circuit design, layout and simulation
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.
Integrated devices in digital circuit design
Hope, G. S.
Aspects of combinational design are examined, taking into account logical operations, truth tables, Karnaugh maps as input output expressions, minimum forms, maximum forms, minterm forms, symbols, fundamental relationships, Karnaugh maps as design tools, the implementation of logic functions, logic and implementation, logic nor implementation, implementation examples, the exclusive or function, symmetrical forms, reduction, and practical circuits. Multiplexers and demultiplexers in combinational circuits are considered along with fundamental mode circuits, event-driven sequential circuits, event-driven circuit implementation using multiplexers, clock-driven sequential circuits, counters and multiplexers in clock-driven sequential circuits, state diagram construction, registers in logic design, a digital system, programming and programming aids, input and output techniques, operation and configuration of independent systems, and a definition of a Boolean algebra. Attention is also given to Intel's and Motorola's executable instructions.
Electromagnetic noise in electric circuits: Ringing and resonance phenomena in the common mode
Directory of Open Access Journals (Sweden)
Shuji Kitora
2014-11-01
Full Text Available It is generally believed that electromagnetic noise originates from the coupling of electric signals in a circuit with electric signals in surrounding materials in the environment. However, the noise phenomenon had not been quantified until now. In order to study the phenomenon of noise, we considered a standard circuit (two transmission lines, to which an additional transmission line was introduced in order to explicitly take into account the effect of conductors in the environment. We performed calculations using a newly developed multiconductor transmission-line theory for the resulting three-line circuit in order to determine the magnitude of the coupling between the circuit and the conductors in the environment under various conditions. We observed ringing and resonance phenomena in the common mode, which influenced the performance of the normal mode as electromagnetic noise. Our findings were confirmed by recent experiments in which conductor lines were arranged in various ways using a printed circuit board (PCB. The ordinary usage of electricity in the standard electric circuit was found to be worst in exciting the common mode noise.
Universal Programmable Quantum Circuit Schemes to Emulate an Operator
Daskin, Anmer; Grama, Ananth; Kollias, Giorgos; Kais, Sabre
2012-01-01
Unlike fixed designs, programmable circuit designs support an infinite number of operators. The functionality of a programmable circuit can be altered by simply changing the angle values of the rotation gates in the circuit. Here, we present a new quantum circuit design technique resulting in two general programmable circuit schemes. The circuit schemes can be used to simulate any given operator by setting the angle values in the circuit. This provides a fixed circuit design whose angles are ...
Multi-photon dressing of an anharmonic superconducting many-level quantum circuit
Energy Technology Data Exchange (ETDEWEB)
Braumueller, Jochen; Cramer, Joel; Schloer, Steffen; Rotzinger, Hannes; Radtke, Lucas; Lukashenko, Alexander; Yang, Ping; Skacel, Sebastian; Probst, Sebastian; Weides, Martin [Karlsruhe Institute of Technology (KIT), Physikalisches Institut, 76131 Karlsruhe (Germany); Marthaler, Michael; Guo, Lingzhen [Karlsruhe Institute of Technology (KIT), Institut fuer Theoretische Festkoerperphysik, 76131 Karlsruhe (Germany); Ustinov, Alexey V. [Karlsruhe Institute of Technology (KIT), Physikalisches Institut, 76131 Karlsruhe (Germany); National University of Science and Technology MISIS, Moscow 119049 (Russian Federation)
2015-07-01
We report on the investigation of a superconducting anharmonic multi-level circuit that is coupled to a harmonic readout resonator. We observe multi-photon transitions via virtual energy levels of our system up to the fifth excited state. The back-action of these higher-order excitations on our readout device is analyzed quantitatively and demonstrated to be in accordance with theoretical expectation. By applying a strong microwave drive we achieve multi-photon dressing of our system which is dynamically coupled by a weak probe tone. The emerging higher-order Rabi sidebands and associated Autler-Townes splittings involving up to five levels of the investigated anharmonic circuit are observed. Experimental results are in good agreement with master equation simulations.
Exploring the Physics of Semiconductor Quantum Dots using Circuit Quantum Electrodynamics
Stockklauser, Anna; Maisi, Ville; Ihn, Thomas; Ensslin, Klaus; Wallraff, Andreas
2015-03-01
Semiconductor quantum dots and superconducting qubits both possess excitations in the microwave domain for which a wide range of novel approaches to create, store, manipulate and detect individual photons have been developed. A key ingredient are coplanar waveguide resonators in which the field energy of an excitation is distributed over a small mode volume. This feature creates sizable electromagnetic fields at the level of individual microwave photons mediating strong electromagnetic interactions with a variety of quantum systems. In an approach known as circuit quantum electrodynamics (QED) we both probe fundamental quantum optical effects and demonstrate basic features of quantum information processing. In this presentation, I will discuss experiments exploring the physics of semiconductor quantum dots in the context of circuit QED. We investigate the coherent dipole coupling of double dots to microwave photons and detect radiation emitted from the dots in inelastic electron tunneling processes. This approach may allow us to explore quantum coherent interfaces between semiconducting and superconducting qubits.
Efficient gas lasers pumped by double-discharge circuits with semiconductor opening switch
Panchenko, Alexei N.; Tarasenko, Victor F.
2012-01-01
A review of applications of double-discharge circuits based on generators with inductive energy storage (IES) and semiconductor opening switches (SOS) for efficient excitation of different gas lasers is presented. Using a pre-pulse-sustainer circuit technique based on inductive energy storage and semiconductor opening switch generators allows the formation of a pre-pulse with high amplitude and short rise-time and provides a sharp increase of discharge current which significantly improves discharge stability and life-time of the volume discharge in gas mixtures containing halogens. A pre-pulse with high pumping power forms a high-density discharge plasma and an inversion population in gas mixtures under study within ∼10 ns and provides both early onset of lasing and conditions for efficient excitation of an active medium from the storage capacitor. As a result, pulse duration, output energy and efficiency of the lasers under study were improved.
Sadomasochism, sexual excitement, and perversion.
Kernberg, O F
1991-01-01
Sadomasochism, an ingredient of infantile sexuality, is an essential part of normal sexual functioning and love relations, and of the very nature of sexual excitement. Sadomasochistic elements are also present in all sexual perversions. Sadomasochism starts out as the potential for erotic masochism in both sexes, and represents a very early capacity to link aggression with the libidinal elements of sexual excitement. Sexual excitement may be considered a basic affect that overcomes primitive splitting of love and hatred. Erotic desire is a more mature form of sexual excitement. Psychoanalytic exploration makes it possible to uncover the unconscious components of sexual excitement: wishes for symbiotic fusion and for aggressive penetration and intermingling; bisexual identifications; the desire to transgress oedipal prohibitions and the secretiveness of the primal scene, and to violate the boundaries of a teasing and withholding object. The relation between these wishes and the development of erotic idealization processes in both sexes is explored in the context of a critical review of the pertinent psychoanalytic literature.
Seidlitz, M; Reiter, P; Bildstein, V; Blazhev, A; Bree, N; Bruyneel, B; Cederkall, J; Clement, E; Davinson, T; van Duppen, P; Ekstrom, A; Finke, F; Fraile, L M; Geibel, K; Gernhauser, R; Hess, H; Holler, A; Huyse, M; Ivanov, O; Jolie, J; Kalkuhler, M; Kotthaus, T; Krucken, R; Lutter, R; Piselli, E; Scheit, H; Stefanescu, I; van de Walle, J; Voulot, D; Warr, N; Wenander, F; Wiens, A
2011-01-01
The ground state properties of ^3^1Mg indicate a change of nuclear shape at N=19 with a deformed J^@p=1/2^+ intruder state as a ground state, implying that ^3^1Mg is part of the ''island of inversion''. The collective properties of excited states were the subject of a Coulomb excitation experiment at REX-ISOLDE, CERN, employing a radioactive ^3^1Mg beam. De-excitation @c-rays were detected by the MINIBALL @c-spectrometer in coincidence with scattered particles in a segmented Si-detector. The level scheme of ^3^1Mg was extended. Spin and parity assignment of the 945 keV state yielded 5/2^+ and its de-excitation is dominated by a strong collective M1 transition. Comparison of the transition probabilities of ^3^0^,^3^1^,^3^2Mg establishes that for th e N=19 magnesium isotope not only the ground state but also excited states are largely dominated by a deformed pf intruder configuration.
Circuit QED with transmon qubits
Energy Technology Data Exchange (ETDEWEB)
Wulschner, Karl Friedrich; Puertas, Javier; Baust, Alexander; Eder, Peter; Fischer, Michael; Goetz, Jan; Haeberlein, Max; Schwarz, Manuel; Xie, Edwar; Zhong, Ling; Deppe, Frank; Fedorov, Kirill; Marx, Achim; Menzel, Edwin; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Huebl, Hans [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany); Weides, Martin [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany)
2015-07-01
Superconducting quantum bits are basic building blocks for circuit QED systems. Applications in the fields of quantum computation and quantum simulation require long coherence times. We have fabricated and characterized superconducting transmon qubits which are designed to operate at a high ratio of Josephson energy and charging energy. Due to their low sensitivity to charge noise transmon qubits show good coherence properties. We couple transmon qubits to coplanar waveguide resonators and coplanar slotline resonators and characterize the devices at mK-temperatures. From the experimental data we derive the qubit-resonator coupling strength, the qubit relaxation time and calibrate the photon number in the resonator via Stark shifts.
Pragmatic circuits signals and filters
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
Quantum Memristors with Superconducting Circuits.
Salmilehto, J; Deppe, F; Di Ventra, M; Sanz, M; Solano, E
2017-02-14
Memristors are resistive elements retaining information of their past dynamics. They have garnered substantial interest due to their potential for representing a paradigm change in electronics, information processing and unconventional computing. Given the advent of quantum technologies, a design for a quantum memristor with superconducting circuits may be envisaged. Along these lines, we introduce such a quantum device whose memristive behavior arises from quasiparticle-induced tunneling when supercurrents are cancelled. For realistic parameters, we find that the relevant hysteretic behavior may be observed using current state-of-the-art measurements of the phase-driven tunneling current. Finally, we develop suitable methods to quantify memory retention in the system.
Printed circuit dispersive transmission line
Ikezi, Hiroyuki; Lin-Liu, Yuh-Ren; DeGrassie, John S.
1991-01-01
A printed circuit dispersive transmission line structure is disclosed comprising an insulator, a ground plane formed on one surface of the insulator, a first transmission line formed on a second surface of the insulator, and a second transmission line also formed on the second surface of the insulator and of longer length than the first transmission line and periodically intersecting the first transmission line. In a preferred embodiment, the transmission line structure exhibits highly dispersive characteristics by designing the length of one of the transmission line between two adjacent periodic intersections to be longer than the other.
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.
Indirect excitation of ultrafast demagnetization
Vodungbo, Boris; Tudu, Bahrati; Perron, Jonathan; Delaunay, Renaud; Müller, Leonard; Berntsen, Magnus H.; Grübel, Gerhard; Malinowski, Grégory; Weier, Christian; Gautier, Julien; Lambert, Guillaume; Zeitoun, Philippe; Gutt, Christian; Jal, Emmanuelle; Reid, Alexander H.; Granitzka, Patrick W.; Jaouen, Nicolas; Dakovski, Georgi L.; Moeller, Stefan; Minitti, Michael P.; Mitra, Ankush; Carron, Sebastian; Pfau, Bastian; von Korff Schmising, Clemens; Schneider, Michael; Eisebitt, Stefan; Lüning, Jan
2016-01-01
Does the excitation of ultrafast magnetization require direct interaction between the photons of the optical pump pulse and the magnetic layer? Here, we demonstrate unambiguously that this is not the case. For this we have studied the magnetization dynamics of a ferromagnetic cobalt/palladium multilayer capped by an IR-opaque aluminum layer. Upon excitation with an intense femtosecond-short IR laser pulse, the film exhibits the classical ultrafast demagnetization phenomenon although only a negligible number of IR photons penetrate the aluminum layer. In comparison with an uncapped cobalt/palladium reference film, the initial demagnetization of the capped film occurs with a delayed onset and at a slower rate. Both observations are qualitatively in line with energy transport from the aluminum layer into the underlying magnetic film by the excited, hot electrons of the aluminum film. Our data thus confirm recent theoretical predictions.
Magnetic excitations in deformed nuclei
Energy Technology Data Exchange (ETDEWEB)
Nojarov, R. [Tuebingen Univ. (Germany). Inst. fuer Theoretische Physik
1995-08-01
Cross sections for inelastic electron scattering and energy distributions of M1 and E2 strengths of K{sup {pi}} - 1{sup +} excitations in titanium, rare-earth, and actinide nuclei are studied microscopically within QRPA. The spin M1 strength has two peaks, isoscalar and isovector, residing between the low-and high-energy orbital M1 strength. The latter is strongly fragmented and lies in the region of the IVGQR, where the (e,e`) cross sections are almost one order of magnitude larger for E2 than for M1 excitations. Comparison with the quantized isovector rotor allows the interpretation of all the orbital M1 excitations at both low and high energies as manifestation of the collective scissors mode. (author).