Showing papers on "Voltage regulator published in 1976"

Computer simulation of integrated circuits in the presence of electrothermal interaction

Abstract: A computer program which predicts the DC and transient performance of monolithic integrated circuits in the presence of electrothermal interactions on the integrated circuit die is described. The thermal modeling of the die/package structure and the numerical analysis procedure is discussed. Experimental and simulation results are compared for monolithic operational amplifiers, voltage regulators, and a temperature-stabilized voltage reference.

Three phase load flow program

Abstract: The paper describes a general three phase load flow program developed for the steady state analysis of any electric transmission network under all possible imbalance conditions such as untransposed EHV lines, single phase loading, single pole switching, etc. Input data preparation and output data interpretation are made easy for program users by using both phase and symmetrical components quantities; however, the load flow problem formulation and solution are all done in phase quantities (A, B, C). The method of solution is the Newton-Raphson method, using optimally ordered triangular factorization to take advantage of the sparsity of network equations. The program has several new features to simulate real three phase operation of power systems and imbalance conditions. For example, the internal induced voltages of generators are balanced, while generator terminal voltages depend on internal machine impedances and the imbalance in machine currents. Also, the steady state performance of the voltage regulator is simulated to maintain some function of the machine terminal phase voltages constant, depending on the actual design of the voltage measurement. Another feature of the program is that it can handle all common transformer connections having two or three windings that are used in HV transmission networks.

Circuit for obtaining DC voltage higher than power source voltage

Abstract: A voltage boosting circuit comprises a plurality of units connected in sequence and each composed of a condenser and a plurality of MOS-FETs without any transformer or diode. The boosting circuit lends itself to miniaturization by integrated circuit technique.

Power supply system with parallel regulators and keep-alive circuitry

Abstract: A dc power supply system comprising two or more voltage regulator units connected in parallel to a common load, there being at least one more regulator unit provided than is required to meet the rated load current requirement. The spare or redundant regulator assumes the load automatically if another regulator fails, and does so in a manner such that it does not interfere with operation of other regulators when they are operating normally and such that its own operation is not affected by the others in the event of their failure. To these ends the power supplies include a decoupling network which is associated with each of the regulators and which operates to prevent any reverse flow of current to that regulator, thus isolating it in the event of its failure, and they include also keep-alive circuitry which forces the redundant or spare power supply to produce an output at all times, to thus enhance its capability to pick up the load instantaneously and with minimized transient in load voltage should one of the other regulators fail.

Voltage and continuity checker

Abstract: A portable test instrument for testing electrical continuity, and diode polarity, AC and DC voltage amplitudes and DC voltage polarity. An electronic switch device has main electrodes connected in an indicating circuit with an electrical supply, a light-emitting diode and a current-limiting resistor. A double pole, double throw switch is manually switchable between continuity and voltage test positions, and with four resistors defines an input circuit interposed between the control electrode of the electronic switch device and probes connectible to a circuit or the like to be tested. In both the voltage and continuity test modes of the instrument, the light-emitting diode is energized only by current from the electrical supply within the indicating circuit. Though proper circuit operation is obtained by manual manipulation of the mode switch between its voltage and continuity positions, the light-emitting diode is automatically protected from damage should the test probes engage a voltage circuit (within the operating voltage range of the instrument) while the instrument is in continuity mode.

Input line voltage compensating transformer power regulator

Abstract: A transformer power regulator and method of utilizing same for efficiently and variably delivering AC power to a load by regulating only a portion of the input voltage equal to maximum expected voltage variation in the input voltage source while transmitting most of the power directly to the load through some of the transformer windings The laminated core structure is continuous and uninterrupted including primary and secondary winding leg portions and back portions defining a main magnetic flux circuit A pair of control winding leg portions, with bridging portions therebetween define a separate control magnetic flux circuit Variable energization of a pair of control windings, one on each of the control winding leg portions, variably controls the magnetic reluctance of the control magnetic flux circuit A primary winding on the primary winding leg portion is connectible to an AC voltage source Most of the power to the load is transmitted through the series combination of a bucking winding on the primary winding leg portion and a secondary winding on the secondary winding leg portion resulting in high power transmission efficiency between the source and the load The bucking winding inductively drops a portion of the input voltage thereacross to compensate for the maximum expected deviation of the voltage source from its nominal value Selective energization of the control windings provide control of the reluctance of the control winding leg portions, thereby controlling the shunting of flux induced in the primary winding leg portion away from the secondary winding leg portion The secondary winding adds a variable voltage to return the voltage at the load to the desired nominal value despite deviations in the voltage source

High voltage transient protection circuit for voltage regulators

Abstract: A high-voltage transient protection circuit for use in combination with a voltage regulator of the type employing an error amplifier to compare a portion of the controlled output voltage against a reference voltage and adjust the output voltage accordingly. The protection circuit can be used with three terminal positive or negative voltage regulators of either the shunt transistor or series pass transistor types. Oscillation of the protection circuit around a selected transient voltage threshold is avoided by providing a hysteresis characteristic in the response of the circuit to a voltage transient. The circuit is preferably embodied as an integrated circuit in a chip of semiconductor material and is particularly well suited for protecting a voltage regulator and associated electronic systems from the detrimental voltage transients encountered in an automotive environment.

Automatic energy control lighting system with automatically variable dc source

Abstract: An automatically variable d.c. voltage source supplies a control signal to a dimmer circuit that controls the brightness of a high intensity gas discharge lamp in response to a varying d.c. voltage. The automatically variable d.c. voltage source produces a varying d.c. voltage at its output which is functionally related to the difference between a voltage from a stable reference voltage source and a voltage produced by a photocell circuit which is responsive to the light level of an area illuminated by the lamp controlled by the dimmer circuit. The variable d.c. source includes circuitry for indicating relamping conditions.

Instrument panel illumination dimming control

Abstract: The brightness of an LED display on an automobile instrument panel is independent of the battery voltage but does depend on the position of the instrument panel illumination dimmer potentiometer. The voltage applied to the LED is limited to a maximum by a zener diode control circuit and that voltage is reduced by a voltage detector circuit which senses the difference between the battery voltage and the dimmer potentiometer output voltage to reduce the LED voltage in proportion to that difference. The voltage detector circuit is disabled when vehicle parking lamps are turned off to insure maximum LED brightness in daytime driving.

Band gap voltage regulator circuit including a merged reference voltage source and error amplifier

Abstract: An improved circuit for a band gap voltage regulator is provided with a merged reference voltage source and error amplifier wherein the circuit operates simultaneously as a generator of the internal reference voltage as well as the small signal error amplifier for comparing a fraction of the output voltage to the reference voltage.

Static shunt compensation for voltage flicker reduction and power factor correction

Abstract: It is shown that a static VAR generator comprising a capacitive filter network and a thyristor-controlled inductor can effectively compensate for rapid and unbalanced load variations and is able to maintain system voltage and power factor, even under extremely adverse load conditions. The performance of such a static compensating system is, however, dependent on the principles of control employed, the adequacy of the VAR rating, and the electrical characteristics of the filter network. In arc furnace applications, the VAR generator must be rated for unbalanced load conditions and the capacitive filter network must be designed to be compatible with the ac system impedance, and with the spectrum of the furnace current that contains both odd and even harmonics.

Resonant switching power conversion

Abstract: A description is given of the operating cycle of the resonant switching dc-to-dc power converter. A method is outlined for precise voltage regulation against line and load changes. Sufficient analysis is presented to form the basis for preliminary design to meet any set of input and output requirements. Performance features are outlined for a flight qualified, highly efficient, light weight resonant switching converter for the U. S. Navy's Navigation Technology Satellite (NTS-2).

Fault indicator for motor vehicle battery charging systems

Abstract: A fault indicator for a motor vehicle battery charging system of the type in which a diode-rectified alternating current generator supplies charging current to the vehicle battery and supplies other loads on the vehicle. The fault indicator is capable of detecting certain faults in the diode-rectified alternator and is capable of detecting certain faults in the generator voltage regulating system. The fault indicator system utilizes current difference operational amplifiers, one of which is connected to detect sharp negative voltage transitions caused by certain faults in the system. The fault indicator also has Zener diodes connected to provide an indication of faults that cause abnormally low or high voltage outputs of the diode-rectified alternator such as an open or shorted voltage regulator. The signal indicator utilized is a light emitting diode and the fault indicator circuit is arranged so as to cause continuous illumination of the light emitting diode under certain fault conditions and a blinking of the light emitting diode during other fault conditions.

Dual voltage charging system

Abstract: A motor vehicle electrical system which is capable of supplying both 12 and 24 volt loads. A pair of 12 volt batteries are permanently connected in series and are charged in series under certain conditions of operation from a 24 volt charging system including an alternating current generator and a bridge rectifier. The output voltage of the 24 volt charging system is maintained substantially constant by a voltage regulator connected with the field of the generator which senses and responds to the output voltage of the bridge rectifier that is applied to the series connected batteries and other 24 volt loads. An auxiliary charging circuit is provided connected between one of the phase windings of the generator and the junction of the series connected batteries for, at times, supplying current to one of the batteries that supplies the 12 volt loads. This circuit includes a series connected silicon controlled rectifier and inductance. The controlled rectifier is gated into conduction whenever the voltage at the junction of the two batteries drops below a voltage corresponding substantially to one-half of the output voltage of the bridge rectifier that feeds the 24 volt loads.

Integrated circuit high voltage DC converter

Abstract: A step-up DC converter suitable for construction as an integrated circuit chip provides a separate rectangular wave oscillator using a silicon transistor and a power amplifier driven thereby which supplies current to the primary winding of a two-winding step-up transformer matched to the constant duty cycle of the oscillator thereby simplifying construction of the transformer and permitting the oscillator and power amplifier voltage step-up transformer functions to be individually optimized for overall high efficiency operation. A hysteresis switching voltage comparator senses the rectified value of the high voltage output from the transformer relative to a stable reference voltage and switches both the oscillator and the amplifier to their standby current condition when a predetermined high output voltage level is obtained and switches both oscillator and amplifier into conduction when the output voltage falls to a predetermined level. A second comparator operates an LED indicator when the output voltage is above a certain level.

Double-voltage, automotive-type alternator

Abstract: To provide a-c output at a voltage substantially higher than normal automotive voltage of 12-24 V, for example output voltage in the 80 to 90 V range to operate windshield and other glass pane heaters, a three-phase alternator is star-connected and has two armature windings which, for example, may be serially connected or may be separately wound, on the same stator, one winding being of comparatively few turns of heavy wire and connected to a rectifier to provide normal d-c on-board voltage for the vehicle, stored in a battery, the voltage being controlled by a voltage regulator connected to the d-c output terminals; the other winding, for example of a much larger number of turns of finer wire providing the high-voltage output at terminals adapted for connection to the heater wires in the windshield, or rear windows, or other window panes.

Plug in regulating power supply

Abstract: A plug in power supply incorporating a ferro resonant transformer mounted on a pair of opposite "E" laminations to provide a low profile magnetic circuit and windings thereon combined with an electronic voltage regulator in which the regulation required therefrom because of the transformer regulation is relatively low and the electronic power component thereof will therefore not be required to dissipate a large amount of power. This enables packaging in a sealed container with a heat sink mounting the power transistor to uniformly distribute the heat thereon and provide a safe plug in power supply.

Power regulating device for controlling exposing means and fixing means in electrophotographic copying apparatus

Abstract: The power regulator of the present disclosure is operated by a source of D.C. power for controlling the A.C. power to be supplied to an exposing device and to a fixing device. It comprises a first circuit for operating the exposing device, a second circuit for operating the fixing device, a switching circuit for alternately operating the first and second circuits and a third circuit for operating the fixing device independently of the operation of the switching circuit so that the fixing device may be warmed up by the operation of third circuit during the operation of the exposing device.

Voltage boost circuit for DC power supply

Abstract: A typical "stand alone" precision power DC to AC solid state converter reres a higher DC supply voltage than is usually available from its utility power sources. The disclosed invention is a voltage boost circuit that provides the DC-bus voltage amplitude for precision power DC to AC solid state converters by transforming only the difference between the available raw power DC voltage bus and the required precision DC voltage amplitude. This DC voltage difference obtained by the circuitry of this invention is boot-strapped to the available DC bus to obtain the required precision DC voltage.

Super compensated voltage control of redundant D.C. power supplies

Abstract: A power supply system is disclosed wherein redundant D.C. power supplies are provided for a single load, each of the supplies being capable of providing full load current so that one of the supplies may be removed without interrupting power to the load. Each of the power supplies has a differential amplifier type of voltage regulator that includes a resistor in series with the output lead so that it is capable of varying the output voltage to compensate for lead and OR-ing rectifier drops.

Multi-voltage vehicular network system

Abstract: To provide a dual-voltage network for the on-board electrical system of automotive vehicles, for example to provide a higher voltage for starting of the vehicle and a normal on-board voltage for operation of vehicle appliances such as lamps, fans, motors, and the like, while using only a single voltage regulator to control the charge voltage for the vehicle battery, a voltage doubler circuit is provided which is connected to the on-board network by a diode and a coupling capacitor connected to an a-c output of a vehicle alternator, the diode being connected between the d-c output and the rectifier connected to the alternator and the capacitor so that a voltage regulator, connected to the d-c output, can accurately control the output voltage of the alternator.

Stabilized DC power supply device

Abstract: A stabilized DC power supply device providing a plurality of different stabilized DC powers with regulated voltage levels. Stabilized DC powers with rated currents of 2A. or less are taken out from transistor series regulator circuits, another stabilized power with rated current of 8-10A. or more is output from a magnetic amplifier regulator circuit and other powers with rated current of 8-10A. or less are obtained from transistor switching regulator circuits. The regulated voltage output from one of the switching regulator circuits is used as an input DC power for the series regulator circuits and is fed to them through an DC-AC inverter circuit and respective rectifier circuits. Input powers to both the switching regulator circuits and the magnetic amplifier regulator circuit are from a DC power source through a single DC-AC inverter circuit. The device is small in size and good in efficiency. Overvoltage and overcurrent prospective circuits are provided to stop the operation of the DC-AC inverter circuit when either overcurrent or overvoltage occurs.

Slip-ringless claw-pole dynamo electric machine, particularly automotive-type alternator

Abstract: To prevent connecting difficulties in the manufacture of automotive-type alternators of the claw pole generator type, resilient spring compression terminals, or contacts are formed, respectively, on a terminal board or on a voltage regulator terminal for engagement with a spring terminal element connected to the fieldwinding so that mere placement of the terminal board or a voltage regulator, respectively, against the springy terminal connections will effect electrical connection and not requiring any internal connecting steps within the alternator and especially at locations of impaired accessibility since they are hidden behind the terminal board, or voltage regulator, respectively.

Shunt voltage regulator

Abstract: An improvement for lowering the source impedance exhibited by a shunt voltage regulator of the type including a self-biased transistor connected between the output terminals. A sensing resistance is connected between the base and collector of the self-biased transistor for providing a voltage responsive to the collector current that controls the conduction of current by a controllable current conductive device between the output terminals.

Current generating system

Abstract: A generator comprises an output winding connected to input terminals of a full-wave rectifier and a field winding. A resistor and diodes are also connected to the input terminals for supplying voltage to a voltage regulator. The generator, the rectifier and the voltage regulator are assembled together within a generator housing, so that a single conducting wire is sufficient for connecting the generator and a battery. The pole cores of the generator are made of low carbon steel the residual magnetism of which has been increased by a cementation process or by insertion of high carbon steel elements.

Alternator-rectifier-regulator unit or mushroom shape for vehicular service

Abstract: The combination of the brush holder of the alternator and the voltage regulator into a unitary structure mounted on a cover fitting over a hole in the alternator casing enables the complete assembly to be economically made in the mushroom shape conventional for d.c. generators of vehicle engines, so that the device can readily be incorporated into an engine of existing design.

Low loss a.c. voltage regulator

Abstract: A high speed a.c. voltage regulator comprises a transformer having a plurality of switchable primary windings across which an unregulated voltage is impressed and which control the regulated voltage, and a secondary winding across which the regulated voltage is generated. During a regulation period, which comprises one cycle of the unregulated voltage frequency, peak unregulated input voltage is compared against an upward ramping reference voltage to control a source of clock pulses, where the instantaneous level of the reference voltage is related to the number of clock pulses generated during a regulation period. The number of clock pulses generated during a regulation period controls the switchable windings.

Investigation of the dynamic oscillations of the Ludington pumped storage plant

Abstract: Dynamic oscillations at a large pumped storage plant equipped with excitation systems of nominal voltage response ratio and connected to a tightly coupled transmission grid are investigated. The results of eigenvalue and transient stability investigations correlate well with the characteristics of the disturbance as interpreted from field measurements. However, the actual dynamic stability margin is somewhat higher than that determined analytically. The excitation control system is shown to be the practicable means for improving damping of the natural mechanical oscillations. Damping can be increased to desired margins during the critical maximum pumping condition by placing the automatic voltage regulators for some of the units at the multi-unit plant on manual control.

Voltage multiplier circuit

Abstract: A new and improved voltage multiplier circuit is provided which converts a relatively low voltage to a relatively high voltage without any undesirable voltage drops across any of the constituent components. A plurality of the disclosed voltage multiplier circuits may be cascaded together to increase the multiplied output voltage, wherein each multiplier stage of the cascaded circuits multiplies the input voltage by two.