Showing papers on "Voltage regulation published in 1976"

Power supply circuit for camera

Abstract: A power supply circuit for a camera wherein a detection circuit which detects the voltage of a power source is provided for supplying an electric power to the electric circuit of the camera only when the detected voltage is above a preset value.In the power supply circuit, the power supply is controlled by a detection output obtained after a voltage detecting action is performed in a stable condition by the detection circuit. The power source voltage is detected in a manner suitable for the characteristic of the battery employed. Further, the voltage detection is performed only momentarily to prevent unnecessary power consumption for voltage detection.

Monitoring system for voltage tunable receivers and converters utilizing an analog function generator

Abstract: A system for monitoring the channel to which a remotely located voltage tunable receiver or converter is tuned includes a comparator for comparing the magnitude of the tuning voltage with an internally generated reference voltage to determine the channel number. The reference voltage is generated by a counter driving a linear digital-to-analog converter. The output of the digital-to-analog converter is modified with an analog function generator to provide a piecewise linear approximation of the receiver tuning voltage versus channel number characteristic. A window comparator is utilized to compare the output of the function generator with the tuning voltage and to stop the counter and transfer the contents of the counter to an output circuit when the magnitude of the reference voltage approaches that of the tuning voltage. The contents of the counter at the time the counter is interrupted is indicative of the channel number of the station being received.

Parallel redundant and load sharing regulated AC system

Abstract: An electrical power system is provided having two power sources, one being a commercial power source and the other being an inverter. Both power sources are connected to the load so as to share the load, approximately equally. A voltage regulator is in series with the commercial power source, and the inverter is synchronized to the commercial power source. Means are provided for failure sensing and isolation of the inverter; and means are associated with the voltage regulator which is connected in series with the commercial power source to block and sense reverse power flow in a direction from the load towards the first power source and to initiate isolation of the first power source from the load when reverse power flow is sensed. Means may also be provided for sensing line quality parameters, particularly voltage, current and frequency of the commercial power source and for isolating it if any such sensed quality is outside of predetermined limits, so that the regulated inverter would be required to assume the load. On the other hand, if the inverter fails the commercial power line assumes the whole load, of which it already has approximately half, so that the system becomes line redundant. The invention may also be applicable to parallel operated line-regulated AC lines each deriving power from independent commercial AC sources.

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.

Voltage multiplier circuit

Abstract: A voltage multiplying circuit comprising a plurality of booster capacitors and switch means for first connecting the capacitors in parallel with a voltage source to charge, then reconnecting the capacitors in series with the source and in parallel with a storage capacitor, to dump the cumulative voltage into the storage capacitor, is characterized in that control signals for actuating the switch means are phased to forestall the formation of a path for leakage current that undesirably discharges the capacitors and reduces the conversion efficiency of the voltage multiplying circuit.

Load control for wind-driven electric generators

Abstract: A generator load curve is precisely matched to a wind-driven motor characteristic by means of a rotor speed-responsive tachometer effecting stepwise control of field current in the generator. Several variations of the tachometer circuit are described. Field current is controlled by an amplifier, and voltage regulation is effected by an override circuit disabling the amplifier.

Starting circuit for switching regulator

Abstract: In a transistor switching type voltage regulation circuit, energy precharge is provided in a by-pass loop around the switching transistor. The instantaneous peak power dissipation at turn-on through the switching transistor is thereby diminished, greatly increasing the reliability of the switching transistor.

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).

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.

Multiple output self oscillating converter regulator power supply

Abstract: A multiple output switching regulator power supply operates as a self-oscillating circuit with a light weight ferrite core transformer and a sense winding used exclusively for voltage regulation purposes. A power transistor switch is employed to selectively connect the transformer primary across a DC source of power to provide energy storage when the switch is closed and to provide energy transfer when the switch is open, by way of transformer flyback. The power transistor switch is controlled by a feedback circuit which includes a current sink connected to selectively divert current away from the base of the power transistor switch and a timing circuit for controlling the operation of the current sink. A capacitor, connected across the sense winding is monitored by a high gain voltage comparison circuit which activates the timing circuit in dependence on the voltage variation on the capacitor.

Thyristor-controlled regulating transformer for variable voltage boosting

Abstract: Based on the principle of the regulating transformer booster, a new voltage regulator is described which selects parts of the supply-voltage waveform by means of phase-controlled thyristor switches and thus provides fast and variable voltage boost. Two different types of control are investigated and their performance is analysed with different types of load. Various experiments are done to substantiate the analytical investigation.

Power supply interruption detecting circuit

Abstract: A power supply interruption detecting circuit which prevents an error in a write signal or sending and receiving signals of a data processing unit in the case of interruption of a commercial power supply or a power supply voltage drop resulting from an accident of other units connected to the same power supply. An abrupt drop of the power supply input voltage is detected by comparing the voltage of a CR circuit of a small time constant with the voltage of a CR circuit of a relatively large time constant. A slow input voltage drop is detected by comparing the voltage of the CR circuit of small time constant with a constant reference voltage. The power supply interruption is rapidly detected in substantially a constant short time regardless of input voltage variations and the write signal or the sending and receiving signals are each clamped at predetermined logic voltage, by which sending and writing of an error signal can be effectively prevented.

A computer study of battery energy storage and power conversion equipment operation

Abstract: This paper presents and discusses results from a computer simulation of a battery energy storage/converter system connected to a representative utility substation. Switching of load, voltage waveforms, voltage levels, fault conditions, and power flow reversal are investigated for both line- and forced-cornmutated converters in the application. The interactions among the battery, the converter and its controls, and the substation are discussed. The investigations have pointed out areas in which further consideration must be given to component selection for the battery/utility interface equipment, for example, dc reactor sizing, harmonic filtering, power factor control, thyristor firing control, and dc current interruption.

Microwave oven temperature indicator and control means

Abstract: There is disclosed a telemetric temperature probe for telemetry of temperatures of comestibles which are heated within microwave ovens. The probe includes a temperature responsive circuit for generating a signal responsive to the temperature of the comestible and an electromagnetic wave broadcasting circuit for telemetric transmission of the signal to a remote receiver which can conveniently be incorporated in the microwave oven and coupled to its control circuit. The probe is provided with facilities to derive power necessary for its operation from the microwave energy generated by the oven and includes, for this purpose, an antenna to receive microwave energy, a rectifier circuit for developing direct current power therefrom and a voltage regulation circuit to produce a source of direct current of controlled voltage for operation of the temperature responsive circuit and the broadcasting circuit.

Application Guide for Shunt Capacitors on Industrial Distribution Systems at Medium Voltage Levels

Abstract: Increased emphasis on energy conservation and reduction of purchased electric power bills have resulted in an increased awareness of the importance of capacitors on industrial systems. Larger banks of capacitors are being considered for installation and many questions relating to the application must be answered. Most of the commonly encountered factors relating to equipment selection, location on the system, protection, and switching criteria are reviewed. Motor terminal capacitor applications are also discussed. Economic justification for the purchase of the capacitors and harmonic resonance, as it relates to capacitor selection and application, are not included.

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.

Qualitative indices for the system voltage and reactive power control

Abstract: Both in off-line and in on-line operation of energy systems, the computer has become an important ally of the engineer. However, results of calculations often obscure properties of steady state of the network. What will the power system network reaction be if one or more nodal voltage varies? How will these variations be reflected at certain nodes? How can one find rapidly a good operating strategy, even if not the best? Answers could be given by using non-linear programming procedures. Nevertheless, fast solutions can be found if heuristic techniques are introduced. This paper proposes to provide the power engineer with a class of indices which clears qualitatively the steady state of energy system network.

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.

Protection circuit for magnetically controlled d-c to d-c converter

Abstract: A push-pull d-c to d-c power converter which is regulated by a magnetic amplifier utilizing pulse-width modulation to control the switching elements. The circuit provides stable operation by utilizing separate control windings in the magnetic amplifier for the voltage regulation and the over-current protection. In addition, symmetry control of the switching elements may be integrated with the voltage regulation by the addition of auxiliary control windings to the magnetic amplifier.

Driving system for gas discharge panel

Abstract: PURPOSE: To reduce the variety of the types of the power source through driving by piling the line voltage or the pulse voltage on the secondary side output of a pulse transformer and then by generating a pulse of high waveheight level different from the line voltage. COPYRIGHT: (C)1978,JPO&Japio

Automatic transfer control device and voltage sensor

Abstract: An automatic transfer control device for selectively energizing an electrical distribution system from a pair of electrical power sources. The device includes voltage sensors for sensing electrical conditions on each of the sources. The device may be used on either three-wire or four-wire systems. The voltage sensors comprise an operational amplifier for artificially generating a phase-to-phase voltage from two phase-to-ground voltages. The artificially generated voltage is used to detect sequence reversal on the sources being monitored. Separate means are provided to select a source from which to draw control power for the device, the control power criterion being different from the transfer criterion.

Sinusoidal mains frequency AC extraction - is performed by filter including rectifier and boosts converter with DC intermediate system

Abstract: A system is used for extracting almost purely sinusoidal mains-frequency current from a.c. voltage or three-phase voltage mains. It transfer the obtained electrical energy into electrically coupled d.c. voltage systems or d.c. voltage intermediate systems, without losses dependent on the design principle used. The supply a.c. voltage mains terminals are connected to an input filter, an uncontrolled rectifier, a boost-converter and the d.c. voltage system or d.c. voltage intermediate system. The boost-converter has at least one electric choke and one diode in boths its long limbs, the latter being connected together via an electronic switch. The d.c. voltage or d.c. voltage intermediate system's voltage is greater than that of the a.c. voltage supply mains, and the switch-over frequency of the electronic switch is high relative to that of the supply a.c. voltage mains.

Push-pull inverter ballast for arc discharge lamps

Abstract: A push-pull ballast for an arc discharge lamp has a high power portion comprising a semiconductor switching inverter and transformer means for step-up or step-down of voltage to be supplied to a load and a low power portion comprising control means sensitive to load parameters as, for example, load current which provides instantaneous control over the switching inverter thereby providing the advantages of high input power factor and precise control over the load voltage and current characteristics.

Regulated power supply

Abstract: A regulated power supply capable of providing an output DC voltage of substantially constant level determined by an AC line voltage to a load irrespective of variations in load current. The regulated power supply comprises first and second rectifiers adapted to generate unregulated DC voltages in accordance with an input AC voltage, a control circuit coupled between the load and the first rectifier and including at least one active device, and a voltage comparator adapted to compare the output of the second rectifier and the output of the detector and generate an output proportional to a difference between the second rectifier output and the detector output, thereby controlling the control circuit and regulating the DC voltage to a constant level corresponding to the input AC voltage irrespective of variations in load current. The regulated power supply can prominently decrease a permissible dissipation of the active device in the control circuit and it is therefore very suitable for a power supply in an audio amplifier.

Development of a high voltage universal divider

Abstract: A new high quality universal voltage divider was developed as a result of theoretical and experimental investigations. Various kinds of tests have been carried out on the divider in order to confirm its performance. The results show that the divider has a response time of about 10 ns and is capable of measuring voltage of various waveforms accurately from lightning impulse to dc voltage.

Field emision electron gun with controlled power supply

Abstract: A field emission electron gun according to this invention comprises a cathode for emitting electrons, an anode, a high voltage source which applies a high voltage between the cathode and the anode in order to cause emission of electrons from the cathode, a reference voltage source, voltage control means for controlling and stabilizing the output voltage of the high voltage source in response to an output voltage of the reference voltage source, means for detecting the value of an emission current from the cathode, means for delivering as an output a signal corresponding to the difference between the detected value and a desired value, and means for applying the output signal to the reference voltage source through a switch. The reference voltage source includes means which, when the switch is in the closed state, controls the output voltage of the reference voltage source in response to the difference output signal, and means which, when the switch is in the open state, continues to hold the output voltage value of the reference voltage source immediately before the opening of the switch as it is. The electron gun of this invention accordingly conducts when the switch is in the closed state, a constant current operation which makes constant the emission current from the cathode, and conducts when the switch is in the open state, a constant voltage operation which makes constant the voltage applied between the cathode and the anode.

Battery charge detector and charging system including such detector

Abstract: A detector, intended particularly for detecting end of charge of a secondary battery under constant current charge, includes a linear input stage producing an output voltage linearly related to the battery voltage. A relay contact is closed periodically by pulses from a clock to connect the output of the input stage to a capacitor and resistor in series. Any change in the output voltage between closure of the contact cause current to flow in the resistor and a comparator compares the voltage across this resistor with a reference voltage. When the battery is charged and the output voltage starts to fall, the negative voltage on the resistor cause the comparator to latch and provide an output signal.