Abstract: A removable controller card comprised of a plurality of Flash EEPROM devices (24) and a controller device (20) is described. The controller device (20) is further comprised of voltage detection circuitry including a variable voltage detector (28) for determining the system voltage level provided by a power supply within a computer (25) and for appropriately enabling a voltage regulator circuit (30) for dividing the system voltage level to a level suited for operation by the Flash EEPROM devices (24) and applying this operational voltage level to the Flash EEPROM devices (24). Upon determining the system voltage level provided by the power supply to be appropriately suited for operation of the Flash EEPROM devices (24), disabling the voltage regulator circuit (30) and providing the system voltage level to the Flash EEPROM devices (24).

Abstract: A switching voltage controller with improved rejection of supply voltage transients, wherein the switching of the voltage controller is controlled by sensing the current through an inductor to provide a current sense signal proportional to the sensed current and comparing the current sense signal voltage to the voltage of a peak signal and the voltage of a valley signal. An error amplifier provides a control signal proportional to the voltage difference between the output voltage of the voltage controller and a reference voltage source. The switching voltage controller provides for improved rejection of transients in the supply voltage by forcing the valley signal to be a first voltage differential Δ' volts below the control signal and the peak signal to be a second voltage differential Δ" volts above the control signal, where Δ" and Δ' are functions of the supply voltage to the voltage controller such that the rate of change of Δ" and Δ' with respect to the supply voltage are substantially equal to each other.

Abstract: An embodiment of the present invention provides a voltage comparator that senses the type of processor, unified or split voltage plane coupled to a mother board. Under the control of at least one multiplexer, voltage regulators supply voltage to the processor. If the processor is a unified voltage plane type, the voltage regulators are coupled together in a master/slave configuration to supply a single voltage to the processor. If the processor is a split voltage plane type, the voltage regulators are coupled to together in a master/master configuration where a core voltage regulator supplies a core voltage to the processor, and an I/O voltage regulator supplies an I/O voltage to the processor. This will allow each regulator to be set at a different voltages to accommodate processor types with different core and I/O voltages.

Abstract: Regulation of load voltage in single-phase applications is becoming an important issue for critical loads. This paper proposes a method to regulate a single-phase AC source by using a series connected auxiliary voltage source. A voltage source inverter, connected in series with the AC supply through a transformer, is used to compensate the input voltage variations to achieve a regulated load voltage. Input power factor improvement can also be obtained, when operating with reactive load, by phase-shifting the compensating voltage with respect to the input voltage. The operation of the compensator in all four quadrants allows the compensation of any voltage drop, and not only the reactive voltage drop within the same path. The total kVA rating for the system is a fraction of the load total power, and is determined by the maximum allowable line voltage variations. The use of a series connection associated with a high-performance modulation technique results in a high-quality output with a small size filter. This paper includes a description of the proposed method, implementation principles, design equations and a design example. Steady-state performance features are investigated. Simulated and experimental results confirm the concept and feasibility of the proposed system.

Abstract: An r.f. excited vacuum plasma processor has a workpiece held in place by a monopolar or bipolar electrostatic chuck having an electrode that develops peak r.f. voltages over a wide amplitude range. A chuck DC power supply source is connected to the chuck. An r.f. peak detecting circuit coupled with the electrode is part of a circuit for controlling the DC voltage applied by the chuck power supply to the chuck. The control circuit supplies an unamplified replica of a DC voltage derived by the peak detecting circuit to the chuck DC power supply source via a DC circuit including only passive elements so the level of the DC voltage applied to the chuck varies in response to variations in the peak amplitude of the r.f. voltage. The peak detector includes at least several series connected diodes having electrodes polarized in the same direction or two stacks of series connected diodes. In one of the stacks, the diode electrodes are polarized in one direction and in the other stack the diode electrodes are polarized in the other direction. The diodes of the peak detecting circuit are arranged so the DC bias voltage supplied to the chuck and the peak value of the r.f. voltage developed at the electrode have the same order of magnitude.

Abstract: Techniques for reducing harmonic distortion in single-switch three-phase boost rectifiers are presented. Optimal pulse-width modulation methods for the main switch to minimize input harmonic current distortion or to maximize the converter power range are described first. Effects of the voltage control loop on the input current waveform are then investigated by using the harmonic balance method. It is found that through proper design of the voltage controller, the input current harmonics in the closed-loop controlled system can be reduced to almost the same level as when the optimized PWM is applied. Simulation and experimental results are included to validate the analysis.

Abstract: A method and apparatus for automatically controlling integrated circuit supply voltages includes, according to one embodiment, a primary voltage regulator and a secondary voltage regulator. The primary voltage regulator supplies one of either a first voltage or a second voltage to a first plurality of inputs of an integrated circuit. The secondary voltage regulator conditionally supplies a third voltage to a second plurality of inputs of the integrated circuit in the event the primary voltage regulator supplies the first voltage, with the third voltage being substantially the same as the second voltage.

Abstract: An output controlling apparatus for a vehicle generator includes MOSFETs for full-wave rectification of a voltage output by the generator, a MOSFET for turning the flow of a field current on and off and a voltage controller for controlling the MOSFETs to sustain the voltage of a battery at a fixed value. In this configuration, the thermal resistance between the MOSFETs is set at a value smaller than the thermal resistance between the voltage controller and the MOSFETs. In addition, the MOSFETs are fixed on a common good heat conductive substrate to reduce the thermal resistance between the MOSFETs. In this way, the accuracy of the voltage controller is prevented from deteriorating and, at the same time, the maximum temperature of the MOSFETs can be reduced.

Abstract: A reduced vibration and reduced noise controller for a switched reluctance machine system and a method for reducing unwanted vibration and noise produced by a switched reluctance machine system. The energization of the voltage across a phase winding in the switched reluctance machine is controlled such that the voltage across the phase winding varies over time in a controlled manner from a first voltage level to a second voltage level following a predefined switching event. The control of the transition of the voltage across the phase winding from the first voltage level to the second voltage level is accomplished through application of a succession of timed voltage pulses to the phase winding at a fixed point in time after the predefined switching event or through use of a capacitor smoothing circuit.

Abstract: A static series voltage regulator (SSVR) for an electric power distribution system protects a load on a feeder branch from voltage dips by boosting voltage under certain conditions. The SSVR contains a 3-phase voltage source inverter and a source bridge, fed from a source, supplying the dc side of the inverter. A series transformer is connected between the power source and a load coupling the inverter output to appear between the power source and the load. A surge filter connected in parallel with the series transformer protects the load from fast front voltage pulses produced by the inverter, and isolation and bypass switches isolate the inverter and series transformer from the power source and load. The inverter is controlled so that during normal operation it acts as a short on the series transformer, and, during a fault that causes a dip in the source voltage, it injects voltage in series with the source voltage to provide a boost action to maintain load voltage at a desired magnitude and balance. The SSVR senses the incoming voltage from the utility and load current and constructs what the load voltage would be in the absence of boost action. This information is processed through a minimum detector to obtain a signal VLOXFL which rapidly responds to a voltage dip but remembers a dip happened for a few cycles. When VLOXFL falls below some threshold then boosting begins to bring load voltage to a desired level. Boosting is halted after VLOXFL exceeds the threshold, or when the load voltage exceeds a high voltage threshold.

Abstract: A control device for a PWM controlled converter having a voltage control portion for comparing with a voltage set value a detected value of a DC voltage output from the PWM controlled converter, connected through reactors to a 3-phase AC power source, for controlling AC input currents supplied from the 3-phase AC power source, to thereby produce current reference signals; an AC reference signal generating portion for generating AC reference signals synchronized with the 3-phase AC power source; a current instruction portion for producing current instruction signals formed by varying the amplitudes of the AC reference signals output from the AC reference signal generating portion in accordance with the current reference signals, and a current control portion for producing control signals to the PWM controlled converter so that the AC input currents vary as instructed by the current instruction signals. The control device portion produces control signals based on a proportional control for a predetermined period after the control starts, and produces other control signals based on a proportional integration control after the predetermined period is terminated.

Abstract: A micropower switching regulator for use in a hysteretic current-mode switching mode power converter monitors a fraction of the voltage output to the load in order to maintain the output voltage at a desired level. When the output voltage is less than the desired level, a proportional current is generated, representative of the difference between the output voltage and the desired level, and used to control the switching regulator causing an inductor to alternate between charging to a hysteretic maximum current level and then discharging to a hysteretic minimum current level, controlled by the switching regulator, until the output voltage is greater than the desired level. The hysteretic maximum and minimum current levels vary as the proportional current varies, so that as the difference between the output voltage and the desired voltage increases or decreases, the current level in the inductor will also increase or decrease, responsively. The inductor is charged and discharged continuously during a continuous conduction mode. During a discontinuous conduction or idle mode, the switching regulator is only turned on when necessary to maintain the output voltage at a level equal to or greater than the desired voltage level. Power is only drawn by the switching regulator, from the input source, when the proportional current is generated, because there is a difference between the output voltage and the desired voltage. In this manner the power provided by the input source is conserved and the desired output voltage level is maintained efficiently.

Abstract: A fixed and a user adjustable voltage reference is alternatively provided by an integrated switch which switches between two current sources according to an input voltage. A fixed reference voltage is achieved by amplifying the current of one of the two current sources according to a predetermined voltage difference between the output terminal and an internal reference voltage. An adjustable reference voltage is achieved by amplifying the current of other of the two current sources according to a voltage difference between the internal reference voltage and an user adjustable voltage. In one embodiment, the user adjustable voltage is achieved by a user adjustable voltage divider circuit.

Abstract: A driver or ballast for the ultraviolet bulb of a water treatment system. The driver includes a step-up transformer and a feedback oscillator connected between the secondary and the primary of the transformer. The secondary of the transformer also is selectably connected through one of two different capacitor compensators depending on water flow through the system. In a low intensity mode, the current and the power factor output of the driver are relatively low, preferably just enough to keep the bulb filaments energized. In a high intensity mode, the current and the power factor are relatively high to power the bulb at a relatively high efficiency. The driver operates at a relatively low DC voltage. A voltage converter selected as function of the local line voltage converts the AC line voltage to the necessary DC voltage.

Abstract: A common-voltage compensation driving apparatus and method and a crosstalk-compensation driving apparatus of an AMLCD detect current flowing through a common electrode for an optional period to compensate for a common electrode voltage by using the current value as a reference and eliminate crosstalk resulting from the variation of a video data value. The common-voltage compensation driving apparatus includes a current detector for detecting the current flowing through a common electrode for an optional period, a proportional voltage generator for integrating the current detected by the current detector to generate a proportional voltage corresponding to the integrated current, a common voltage generator for compensating the proportional voltage of the proportional voltage generator to a common electrode voltage during a compensating period shorter than one horizontal scanning period, and a controller for controlling driving times of the current detector, proportional voltage generator and common voltage generator. The method therefor is performed by a current detecting step, a proportional voltage generating step, and a common voltage generating step. The crosstalk compensation driving apparatus has the current detector, the proportional voltage generator, a data signal voltage compensator for compensating the proportional voltage of the proportional voltage generator to a data signal voltage output during a compensating period shorter than one horizontal scanning period, and the controller.

Abstract: A VAR generator compensation system wherein the voltage of the capacitor or reactor bank is changed as a means of adjusting the phase angle is taught. Briefly stated a reactive bank such as a capacitor bank is connected to the secondary of an autotransformer such that the voltage of the reactive bank is controlled by the autotransformer. The line and load are connected to the primary of the autotransformer, such that changing the voltage of the autotransformer and hence the secondary voltage connected to the reactive bank, thus changes the VARS generated on the grid or system.

Abstract: A current supply circuit for an electronic apparatus having standby, normal and economy modes of operation includes a remote control receiver which responds to a remote control signal from a remote control unit to select either mode of operation. A voltage source provides a main voltage which is detected to produce a switching voltage when the main voltage is present. The switching element of a voltage responsive switch is connected to a first input contact in the presence of the switching voltage and to a second input contact in the absence of the switching voltage. The output contact of the voltage responsive switch is connected to an input terminal of the remote control receiver and to a first input terminal of the filter. The output contact is selectively connected to the first and second input contacts in response to the respective presence and absence of the switching voltage to apply a first operating voltage to the first input contact in the presence of the switching voltage and a second operating voltage to the second input contact to place the current supply circuit into the economy mode of operation in the absence of the switching voltage.

Abstract: A digital voltage regulator for an electrical power system including a permanent magnet generator (PMG), an exciter, and a main generator. A controller multiplies the frequency of the generator output voltage by a predetermined value to provide a sampling signal having the multiplied frequency and synchronized with the generator output voltage. The controller also provides a sawtooth voltage signal having a repetition rate equal to the frequency of the sampling signal and an incrementing rate determined by the system clock signal. The generator output voltage is sampled at the frequency of the sampling signal. When the difference between the sampled signal and a reference voltage is greater than the sawtooth voltage, the PMG voltage is switched to provide voltage for the exciter field winding.

Abstract: A voltage-controlled oscillator includes at least one voltage-controlled delay element and a reference voltage generator. The voltage-controlled delay element has first and second voltage supply inputs, a control voltage input, a signal input and a signal output. The reference voltage generator has a voltage input coupled to the control voltage input and a voltage output coupled to the first voltage supply input.

Abstract: With the large number of wind energy conversion systems established in India, the utility grid is facing a severe problem of poor power factor at low wind speeds. This is because of the reactive power taken by the induction generator from the grid. The use of an AC voltage controller, as in the case of an induction motor, is suggested as one of the methods to improve the power factor. In this paper, detailed investigations are carried out on a grid connected induction generator with voltage control. The generator performance was determined theoretically under different operating conditions. Experimental investigations carried out using an autotransformer as a voltage controller confirm the theoretical results. Further, the feasibility of using a three phase thyristorised AC voltage controller, used in a wind energy conversion system for the soft start of an induction machine as a motor, for the power factor improvement of the system, is studied. Here, the problem is that the voltage applied to the induction generator can not be reduced below a particular value. The reason for this problem is analysed in this paper and a solution suggested.

Abstract: The present invention is an apparatus for storing a voltage level within a storage element such as an EEPROM. The apparatus includes a track and hold circuit that receives the voltage level to be stored and an integrator that determines a target voltage to be applied to the storage element representative of a voltage level less than the received voltage level. The apparatus further includes a voltage ramp circuit that applies a voltage ramp signal to the storage element for increasing an amount of voltage held in the storage element while simultaneously reading a voltage level of the storage element to determine whether the voltage of the storage element matches the target voltage and a comparator that deactivates the voltage ramp signal when the voltage of the storage element matches the target voltage. The integrator also reads a resulting stored voltage of the storage element, determines a new target voltage, and controls the voltage ramp circuit and the comparator to apply the new target voltage to the storage element a predetermined number of times.

Abstract: The present invention relates to an output stage for an electronic memory device and for low supply-voltage applications and is the type comprising a final stage of the pull-up/pull-down type made up of a complementary pair of transistors inserted between a primary reference supply voltage and a secondary reference voltage and a voltage regulator for the control terminals of said transistors. The regulator is a voltage booster using at least one bootstrap capacitor to increase the current flowing in the final stage by boosting the voltage applied to said control terminals.

Abstract: This paper proposes the structured singular value (/spl mu/) approach to the problem of designing an output voltage regulator for a buck-boost power converter with current mode control. This approach allows a quantitative description of the effects of reactive component tolerances and operating point variations, which strongly affect the power converter dynamics. At first, a suitable linear power converter model is derived, whose parameter variations are described in terms of perturbations of the linear fractional transformation (LFT) class. Then, /spl mu/-analysis is used to evaluate the robustness of a conventional PI voltage regulator with respect to the modeled perturbations. Finally, the approximated /spl mu/-synthesis procedure, known as D-K iteration, is used to design a regulator ensuring robust performance. Simulated results are presented, describing the small and large signal behaviour of a reduced-order approximation of the /spl mu/-synthesised controller.

Abstract: The object of the invention is to provide a charging generator 1 which can avoid occurrence of overvoltage due to failure of equipment, which comprises: an a.c. generator 10 having armature windings 10a, 10b, 10c and a field winding 10d for generating an a.c.; a rectifier 11 having a plurality of power zener diodes 11a-11f having an intrinsic breakdown voltage Vz for converting the a.c. output from the armature windings to a d.c.; a current inhibit means which receives the d.c. output from the rectifier via field winding 10d and inhibits a field current which flows through the field winding; a voltage detection means for detecting a voltage of the d.c. output from the rectifier; and a voltage regulator 13, which includes a protection control means for controlling the current inhibit means in accordance with a result of judgment which is larger between a detected value of the d.c. voltage and a predetermined protection cut-off voltage VB, for regulating the d.c. voltage in the vicinity of the protection cut-off voltage VB by inhibiting the field current, and wherein the relationship between breakdown voltage Vz and protection cut-off voltage is set Vz>VB.

Abstract: A circuit and method for switching an output terminal from a first voltage level to a second voltage level through a buffered transition includes two voltage sources, a resistor and first switch connected in series and electrically coupled between the first voltage source and the output terminal for providing a suitable resistance for buffering a transition from a first voltage level to a second voltage level. A second switch is electrically coupled between the first voltage and the output terminal. A third switch is electrically coupled between the second voltage source and the output terminal. A programmable logic controller (PLC) controls the three switches in a predetermined sequence to allow switching a voltage source from the first source to the second source through a buffered transition provided by the resistor.

Abstract: PROBLEM TO BE SOLVED: To make it possible to continue operation of a system with a low loss even if there is a trouble in the system by changing a control method between a pulse amplitude modulation method and a pulse width modulation method according to the state of the system voltage. SOLUTION: A reactive power detected value and a reative power set value is compared with each other and reactive power is controlled by a reactive power controller 11. The reactive power controller 11 outputs ΔEd through a limiter 13. Then, a standard DC voltage set value Ed0 is added to ΔEd to obtain a DC voltage set value Edr. Edr is compared with DC voltage Ed and DC voltage is controlled by a DC voltage controller 12. The DC voltage controller 12 outputs Uq. Meanwhile, AC voltage Vs of the system is detected and then a P-axis voltage component Vp and a Q-axis voltage component Vq are found by a three-phase/two-phase inverting circuit 31. Then, Uq is added to Vq. Uq+Vq and Vp are inverted phase by phase by a two-phase/three-phase inverting circuit 32 and are input into pulse generating devices 21-23.

Abstract: A first intermediate direct voltage is generated from a current source or on-board voltage, and a second sinusoidal intermediate alternating voltage is generated with a current inverter. This intermediate alternating voltage is transformed by one or more transfer systems to the various triggering and maintaining voltages of different cold cathode discharge lamps. Frequency-synchronous dimming is regulated by the pulse-pause ratio of a pulse group regulator in a broad frame by optically commanded triacs which are triggered in the zero crossing. The preconditions for the starting and maintenance characteristics of the lamps are thus always ensured.

Abstract: An apparatus for correcting a chromaticity diagram by a variable brightness includes: a first grid voltage controller for controlling a first grid voltage to be a voltage of a predetermined level; a first grid voltage detector for detecting the first grid voltage output by the first grid voltage controller; a phase inverter for inverting a phase of a voltage signal detected by the first grid voltage detector; an analog-to-digital converter for converting the inputted voltage signal, which has been phase-inverted by the phase inverter, into a digital signal; a microprocessor for receiving the digital data of the first grid voltage output from the analog-to-digital converter to produce and output error data; a digital-to-analog converter for converting the error data supplied from the microprocessor into an analog signal, and a cut-off controller for receiving the analog signal output from the digital-to-analog converter and correcting a color-difference signal. The RGB characteristic changes and focus changes according to the first grid voltage changes are automatically corrected and color blur and visibility factor lowering can be prevented.

Abstract: The static condenser (STATCON) is a shunt connected voltage source converter using self commutating devices like GTOs. The principle of operation is similar to that of a synchronous condenser. This paper is concerned with the application of the STATCON for the reactive power compensation of a long transmission line by regulating the voltage at its midpoint. The design of the voltage controller and the analysis of its dynamic behaviour using eigenvalue analysis and digital simulation is presented. An important observation is that the plant transfer function is generally of the nonminimum phase type. This precludes the use of large gains in a PI controller as there is a risk of instability of an oscillatory mode of frequency between 200-300 rad/s. Eigenvalue analysis using a linearized model was carried out to design a compensator in a cascade with an integral controller to overcome this problem.