Showing papers on "Voltage published in 1981"

Device for firing discharge lamp

Abstract: PURPOSE:To stably heat a filament for a discharge lamp by bringing the center of the winding width of an output winding of an output leakage transformer coincident to the center of the winding width of a filament winding and allowing the voltages produced at both the windings to become in phase. CONSTITUTION:In a leakage transformer 28, input windings 28a, 28b are wound through a bobbin 37 on a core 36, and a base winding 28c and filament windings 28e, 28f are wound partly thereon. The filament windings 28e, 28f are formed in the lowermost and uppermost layers of the output winding 28d in such a manner that the center of the width of the winding coincides approximately with the center of the output winding 28d. According to this construction, since the voltages of the windings 28e, 28f becomes in phase with the voltage of the winding 28d, the heating states of the filaments 28F1, 23F2 become stable, the formation of the filament spot after ignition is rapid, and the progress of blackening of the discharge lamp due to the energization and deenergization of the lamp can be largely improved.

Neutral-point-clamped PWM inverter

Abstract: A neutral-point-clamped PWM inverter arrangement for reducing output harmonic content. The arrangement includes a DC power source circuit having positive, negative and neutral terminals, a first group of switching elements connected at one end to the power source positive terminal, a second group of switching elements connected at one end to the power source negative terminal and at the other end to the corresponding switching elements of the first group, respectively, a third group of switching elements connected between the power source neutral terminal and the junctions of the switching elements of the first group and the second group, and a fourth group of switching elements connected in parallel with corresponding switching elements of the third group, respectively. Output terminals are connected to points where a switching element of the first group is connected to the corresponding ones of the second group to provide phase output voltages. The switching elements of the first to fourth groups are so controlled that the maximum voltage value is half the voltage applied by the DC power source circuit. The voltage across each phase output terminal and the neutral terminal changes first to the potential of the positive terminal, then to the potential of the neutral terminal, next to the potential of the negative terminal, again to the potential of the neutral terminal and once again to the potential of the positive terminal.

Stress-Wave Probing of Electric Field Distributions in Dielectrics

Abstract: The spatial distribution of the electric field within a dielectric sample is shown to be obtainable unambiguously from the time dependence of the open-circuit voltage or short-circuit current during the propagation of a stress wave across the sample. Experiments in which the pressure wave is generated by the impact of a pulsed laser beam on a metal target bonded to the dielectric plate under investigation have led to the first straightforward visualization of electric field distributions in solid dielectrics.

Electro-wetting displays

Abstract: We show that a novel effect, electro wetting, can be the basis of passive displays which (i) switch reversibly from transparent to white, (ii) have fast response time (<1.0 ms),and (iii) can be operated with low voltages (<1.0 V) and low power consumption (<1.0 mW/cm2). We derive the operating parameters and report experiments demonstrating the concept of electro‐wetting displays.

Hot-electron injection into the oxide in n-channel MOS devices

Abstract: In recent years, interest in hot-electron injection current in MOS devices has increased due to advances in device concepts and technology. The injection current to the gate is the mechanism for programming FAMOS devices and determines the potential degradation of short-channel MOS devices due to electron trapping in the oxide. This work presents an accurate indirect current measurement technique based on charge transport to the floating gate in a FAMOS structure. The measurement bypasses effects of trapping and local heating, allowing full characterization of parameter, voltage, and temperature dependence down to gate current levels of 10-16A. Based on this characterization, a new qualitative model of hot-electron injection into the oxide is proposed. The basic assumption in the model is the spherical symmetry of the momentum distribution function of the hot electrons. This assumption leads to the experimentally observed dominant role of the lateral electric field in the pinchoff region in determining gate current behavior. The model provides an explanation of gate current parameter and voltage dependence, and suggests correlation between gate current and substrate impact ionization current in a range of operating voltages. This correlation is substantiated experimentally for a range of device parameters and voltages.

New Static VAR Control Using Forced-Commutated Inverters

Abstract: This paper describes the system outline and the operating results of a new type of 20MVA Static VAR Generator (SVG), which is already in operation in electric power field since January of 1980. This SVG consists of force-commutated inverters of the voltage source and can be operated in both, inductive and capacitive modes, by simple control of the output voltage of the inverter. Special emphasis is placed on the system outline, electrical designing features and the operating results which coincide with the theoretical analysis.

Battery testing techniques

Abstract: A system and method for testing a battery having an internal impedance by generating digital battery parameter values corresponding to the battery parameters at different points in time by means of current, voltage and temperature measurement circuits and an analog-to-digital converter. An electrical load is periodically placed on the battery and the battery is also charged between loadings in order to provide battery parameter values during different battery conditions. A microprocessor coordinates the testing of the battery and the measuring of the battery parameter values, as well as the calculation of test criteria based on those values in order to quickly and accurately analyze the condition of the battery.

A General Approach to the Endurance of Electrical Insulation under Temperature and Voltage

Abstract: The paper deals with the models for estimating the life of electrical insulation under multiple stress conditions. In a first approach, simple models, the inverse-power law and the exponential, are considered for electrical aging; they are combined with the Arrhenius model to find the life equation of insulating materials under temperature and voltage. This equation is discussed and the corresponding surface studied and drawn. Since experimental results often disagree with these models in the low-stress range, an improved electrical model is proposed in which a threshold electrical gradient is introduced. This also involves the introduction of a threshold temperature, variable with electrical stress. Using some simple assumptions about the thresholds, it is possible to attain a new model for insulation life under combined stresses, perfectly symmetrical in thermal and electrical stress. The results of both voltage endurance tests on various insulating materials and multiple stress tests on a composite material agree with the proposed model and show its capability by accurately predicting the longtermerm behavior of insulation.

Automatic voltage imbalance detector

Abstract: A device for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

Motor vehicle fuel-waste indicator

Abstract: A method and electro-mechanical device, for use on motor vehicles, which signals the driver to ease up on the gas pedal whenever he is applying excessive pedal pressure which causes fuel waste. The device utilizes a vacuum-operated electric switch that detects any drop in engine intake-manifold-vacuum below a pre-selected level, caused by excess foot-pressure on the gas pedal, and applies voltage to an electric vibrator which is coupled to the gas pedal. On feeling the gas pedal vibrating, the driver reduces his pedal pressure sufficiently to allow engine vacuum to rise above the pre-selected level, thereby causing the vacuum-switch to cut off electric current to the pedal vibrator. This cessation of vibration serves as a feed-back signal to the driver that his pedal pressure, and hence vehicle performance, is restored to an economical level.

Controlling method for inverter

Abstract: PURPOSE:To eliminate irregular rotation and unstability at a low speed by constantly controlling a DC voltage in PWM mode in low speed range of several 10% of speed at several 10% and controlling it in PAM mode over several 10%. CONSTITUTION:A PWM modulator 17 controls PWM according to a command value S3 with the reference output S1 of a speed reference circuit 15 being 0-30%, thereby controlling an inverter transistor 5 ON or OFF by a base drive circuit 16. The output S5 of the modulator 17 becomes constant value between 30 and 100% of the reference output S1, instead a voltage pattern generator 13 outputs as a command value an output S2 proportional to the reference output S1, controls a voltage control circuit 11 in response to the output the difference from the DC voltage detected by a DC voltage sensor 12, thereby controlling the DC output voltage of a thyristor 2 equal to the command value V1.

Microprocessor controlled voltage regulating transformer

Abstract: A voltage regulating transformer utilizing a microprocessor and a versatile multipurpose set of hardware modules and software modules it is described. A standard tap changing mechanism is driven in response to an analog control signal to change the output voltage of the transformer in response to digitally sampled values of voltage and current which have been transformed from the time domain to the frequency domain through a software program using Fourier transform techniques. The output current is also transformed and digitally processed to determine the power factor and the direction of power flow through the transformer. By inserting the digital values of the line characteristics to the load, line drop compensation is provided for. The difference in voltage across the input and output transformers is transformed to a digital signal and internally processed to provide an indication of the position of the tap changing mechanism without relying upon mechanical devices. The various software and hardware modules are designed so as to be readily utilizable in other electrical distribution controls.

Variable high frequency ballast circuit

Abstract: A variable high-frequency ballast circuit for igniting and operating energy saver discharge lamps includes a high frequency inverter that energizes the lamps with a given high frequency voltage at which reliable lamp ignition is assured. The lamp current is monitored so as to automatically increase the lamp operating frequency to an optimum value as soon as the lamps ignite.

Large-signal circuit model for simulation of injection-laser modulation dynamics

Abstract: A new large-signal circuit model of a heterojunction injection laser is presented. The model includes the current/voltage characteristics of the semiconductor heterojunction and the electro-optical dynamics of the active layer. It enables the laser and its electrical drive circuit to be analysed in a unified manner. The model can be easily implemented on general-purpose nonlinear circuit analysis programs, and does not require specialised laser analysis software. The model is illustrated with a number of simulated laser response characteristics.

A unified model for hot-electron currents in MOSFET's

Abstract: A simplified and efficient method to account for two-dimensional effects on the electric field in the pinched-off region near to the drain of a MOSFET is shown to provide accurate predictions of the drain, gate and substrate currents, Measurements agree well with theory for a wide range of processing parameters and geometries.

Free Conducting Particles in Compressed Gas Insulation

Abstract: This paper presents an electrostatic study of free conducting particles that contaminate com pressed gas-insulated high voltage apparatus and transmission lines Analytical and numerical techniques are used to describe the effect of the particle charge and the magnitude of the ambient electric field on the field intensification on and near the particle surface The electrostatic force acting on filamentary and spherical particles as they lift off one electrode and move towards the other, is also analyzed The techniques developed in this study enable the construction of a breakdown voltage profile which describes the instantaneous voltage required to break down the insulation as the particle moves between electrodes

Semiconductor memory device

Abstract: PURPOSE:To reduce the current consumption and occupied area, by using a transfer gate MOSFET of different conduction type as driving MOSFET, for a given area at the same time CONSTITUTION:Ion injection is being made so that the threshold voltage value specified is given to transfer gate P type MOSFETQ1, Q2 and driving N type MOSFETQ3, Q4 Thus, when a voltage between the gate and the source is zero, the current between the drain and the source is greater for FETQ1, Q2 than FETQ3, Q4, and the increment of the gate voltage required to change one digit of the current between the drain and the source at the gate voltage less than the threshold value is greater for FETQ1, Q2 than FETQ3, Q4 Further, FETQ1, Q2 are operated at the gate current region at threshold value or less for load at the same time Accordingly, the current consumption is lowered for the memory unit in comparison with use of a high resistance and the occupied area is decreased

Electrically alterable double dense memory

Abstract: An electrically alterable double dense memory is provided which includes a field effect transistor having first and second spaced apart diffusion regions of a first conductivity defining a channel region at the surface of a semiconductor substrate having a second conductivity. First and second floating gates are disposed over the first and second diffusion regions, respectively, and each extends over an end of the channel region. First and second dual charge injector structures or enhanced conduction insulators are disposed between the first and second floating gates and a common control gate of the transistor. A word line is connected to the control gate and first and second bit lines are connected to the first and second diffusion regions. By applying appropriate pulses to the word and bit lines, a selected floating gate can be charged to alter the conductivity of the end of the channel region associated with the selected floating gate and then discharged at will. In this manner binary digits of information are stored in each of the two floating gates and altered as desired. By applying appropriate voltages to the control gate and to one of the first and second diffusion regions, the stored information or charge condition of the floating gate associated with the other of the first and second diffusion regions can be determined.

Ink-jet printing apparatus

Abstract: An ink-jet printing apparatus having a plurality of nozzles for projecting ink droplets which are selectively deposited on a printing medium in accordance with an information signal so as to form a printed pattern, such ink-jet printing apparatus comprising means for causing ink droplets used for printing to project from each nozzle in accordance with an information signal, a common power source for supplying a desired voltage to the ink-drop forming means provided at each nozzle thereby operating them, and switching means connected between the ink-drop forming means and the common power source and controlled by the information signal, the output of the power source being selectively supplied through the switching means to the ink-drop forming means, so that the driving system for driving the ink-drop forming means and the control system therefor can be separately provided, thus enabling a number of nozzles to be effectively controlled by a lowest control voltage.

Apparatus and techniques for electric tomography

Abstract: Apparatus for electric tomography comprising a coupling medium for receiving an object to be examined, a plurality of electrodes disposed in the coupling medium and arranged in a three dimensional array; multiplexing apparatus for applying electric voltages at selected first pluralities of electrodes and simultaneously measuring electric currents at corresponding selected second pluralities of electrodes in a desired sequence; and computation apparatus coupled to the multiplexing apparatus for originally estimating the electrical properties at a multiplicity of locations in the object to be examined, these locations being arranged in a three dimensional imaginary grid defined in the object to be examined and subsequently correcting the conductivity estimates at each of the multiplicity of locations on the basis of the measured currents by an iterative process.

Theoretical Treatment of the Transport Equations for Electrons and Ions in a Mixed Conductor

Abstract: The transport equations for the ions and electrons in a mixed conductor are considered. An exact solution of these equations in the steady state is given for a fixed ion concentration. Explicit analytic expressions are derived for the variation of electron concentration with position and applied voltage. From this, the electron chemical potential variations within the mixed conductor can be obtained. Explicit analytic expressions are also derived for the dependence of the current on the external voltage. The power output and energy conversion efficiency are then calculated for a fuel cell based on a mixed conductor. An example is discussed quantitatively. It is a high temperature fuel cell based on doped ceria and operating at 800°C.

Transformerless noninverting buck boost switching regulator

Abstract: A buck boost type noninverting transformerless switching regulator utilizes two synchronized switches operating at either the same or different duty cycles to independently control energy storage and energy delivery from a two terminal inductor element to the output load. A wide range of output voltage is available and is continuously regulated.

Device for firing discharge lamp

Abstract: A lighting circuit for an electric discharge lamp according to the present invention is constructed in such a way that a switching device is provided at an output terminal of a high frequency inverter which produces a substantially sinusoidal output voltage, and that, by controlling this switching device, an output to the low pressure electric discharge lamp is stopped at the rising part of the abovementioned output voltage in its half cycle, while the output is supplied to the low pressure electric discharge lamp at the voltage level in the vicinity of the maximum instantaneous value thereof. By use of the high frequency inverter of a smaller capacity and less radio noise than those in the conventional device, the operating efficiency of the low pressure electric discharge lamp can be increased.

Method and apparatus for testing a battery

Abstract: The operating condition and/or characteristics of a battery is tested by obtaining the dynamic voltage-current characteristic of the battery as a function of the charge condition thereof. A controllably varying charging current is supplied to the battery, and the voltage produced across the battery while that current is supplied is measured. The dynamic voltage-current characteristic is obtained as a function of the measured voltage and supplied current. This voltage-current characteristic is compared to predetermined voltage-current characteristics representing batteries of the type being tested in order to determine the operating condition and/or characteristics of the battery under test.

Control system for electric powered vehicle

Abstract: In a control system for an electric powered vehicle of the type including a D.C. motor drivingly connected to roadway engaging drive wheels, there is provided an improvement. A control system for this type of vehicle has a controller for operating the D.C. drive motor with a voltage having a pre-selected magnitude, a first storage battery supported on the vehicle and having a charging mode and a discharging mode with a voltage rating during both of the modes being generally equal to the pre-selected magnitude, a circulation pump associated with the first storage battery for activating this battery, also driving the circulation pump during the discharge mode of the first storage battery. The improved control system in this type of an environment includes a second storage battery, a manually actuated starting switch for allowing the D.C. motor to be driven by the first storage battery, the second storage battery also driving the circulation pump for limited time after manual actuation of the starter. Also, the improved control system is useable when two pumps are associated with the first storage battery and then includes a control circuit for driving one pump selectively by the second storage battery and an enabling circuit for actuating the drive control by the second storage battery so that the vehicle responds to the second storage battery at least during initial operation.

Validation of Synchronous Machine Models and Derivation of Model Parameters from Tests

Abstract: Results of transient response tests on synchronous generators are presented along with derivations of generator model parameters from data.

Instabilities in current-mode controlled switching voltage regulators

Abstract: A survey of the instabilities of switching voltage regulators with different types of current-mode controllers (including LC3 or constant-hysteresis; MC2 or constant-frequency and constant off-time versions) is presented. Apart from the well-known open-loop oscillation of the constant frequency regulator above 50% duty ratio, other instabilities can also arise by increasing the ac loop-gain. At the constant-hysteresis controller the operating frequency changes, at the other types continuously or hysteretically arising subharmonic oscillation appears. These phenomena can be analysed by taking into account the effect of the amplified and fed-back ripple voltage to the operation of the current comparator. Calculations were accomplished in order to establish maximum usable ac gains for the three basic power converter topologies (buck, boost and buck-boost) and for the above mentioned controllers. Experiments were also carried out for several particular power circuit and controller combinations showing close correspondence to theoretical results.

Multiple-fault location of analog circuits

Abstract: This paper deals with multiple-fault detection for linear analog circuits. The method proposed is based on measurements of voltage using current excitations and has been developed for the location of a number of faults. It utilizes certain algebraic invariants of faulty elements. Computationally, it depends on checking the consistency or inconsistency of suitable sets of linear equations. The equations themselves are formulated via adjoint circuit simulations.

Semiconductor integrated circuit with a response time compensated with respect to temperature

Abstract: A current-controlling MOS transistor is connected between a power source and an MOS circuit. A control voltage which has a level related to temperature is applied to the gate electrode of the control MOS transistor in order to compensate for current reduction at high temperatures due to the lowering of the mobility of minority carriers. The response time of the MOS circuit is made less dependent on temperature as a result of the current compensation.

Method of equalizing the voltages of the individual cells of storage batteries

Abstract: There is disclosed a method of equalizing the voltages of the individual cells of a storage battery that consists in the steps of, 1. providing a single input circuit type of d.c. to d.c. converter incorporating multiple output circuits equal in number to the number of cells of the battery to which it is planned that the converter will make connection, with the converter so designed and employed that, with its input circuit connected to the terminals of the battery, and one of each of its output circuits connected across one of each of the cells of the battery, flow of cell equalizing current will hold low so long as the downward departures of the voltages of the battery's cells from average cell voltage hold below a prescribed index value. 2. providing, via method of converter design and employment, and choice of the above referred to index value, so that, for a given type, size, and prior condition of use of a battery, employment of the converter as in step 1 above can be expected to provide a cost-effective way to both favorably affect the equality of the battery's cell voltages, and avoid cell voltage reversal during battery discharge under contemplated conditions of the battery's use. 3. providing to connect one of each of the output circuits of the converter across one of each of the individual cells of the battery. 4. providing so that when the battery is in active use the input circuit of the converter will be energized from the battery's terminals. 5. providing a means of indicating when the extent of inequality of the cell voltages of the battery is such as to cause converter input current to exceed a preset value.