Showing papers on "Voltage regulator published in 1971"

High dc to low dc voltage converter

Abstract: Transformerless high DC to low DC voltage conversion is achieved by alternately charging a plurality of capacitors in series from the input voltage source, and discharging them in parallel into the load. The charging and discharging are effected by transistor switches, which are in turn controlled by the voltage across one of the plurality of capacitors. Charging stops, and discharging begins, when this voltage rises above a first predetermined value; discharging stops, and charging begins, when this voltage falls below a second, lower, predetermined value. During charging, voltage across the load is maintained by a permanently connected reservoir capacitor. The difference between the predetermined voltage values, and hence the ripple on the output voltage, is preselected by certain circuit constants, whereas the mean of the two values is controlled by comparing the DC component of the output voltage with a reference value, so as to maintain the DC load voltage constant despite variations in load current.

A High Initial Response Brushless Excitation System

Abstract: A high initial response excitation system retaining the advantages of the absence of commutators, collectors and brushes while responding with the speed of an electronic exciter has been developed. Calculated performance of this system has been firmed by factory tests. With the exciter loaded, the excitation system achieved 95% of ceiling voltage in 0.016 seconds following a 10% step change in the voltage regulator sensing signal. In addition to the high initial response capability, the excitation system also includes supplementary feedback control for improving the small signal dynamic performance characteristic of the exciter. With the addition of feedback, the effective exciter time constant is reduced by a factor of thirty compared to its value without feedback. The tests confirm that low time constants and high initial response can readily be attained in an excitation system which includes a brushless exciter with non-controlled rectifiers.

High current voltage/current regulator employing a plurality of parallel connected power transistors

Abstract: In a high current regulator employing high power parallel connected pass transistors, equal current sharing is forced by comparing the voltage drop across small emitter resistors and by means of differential (operational) amplifiers forcing these voltage drops to be substantially equal at all output currents. Three additional quantities are controlled; first, output voltage; second, output current; and third, fold-back overload current characteristics. The overall performance in all major characteristics is enhanced by the liberal use of high gain integrated circuit operational amplifiers.

Voltage and current regulator with automatic switchover

Abstract: A system for energizing an inductive load includes a voltage regulator for providing a constant voltage across the load until the current builds up to a particular value, and a current regulator which then takes over to provide a constant holding current at a lower value. The voltage regulator may include a closed loop for holding the voltage across the inductive load constant or may respond to a regulated voltage value to control a power stage for providing a constant voltage. The voltage across a sensing resistor in the power stage controls the crossover from the voltage regulation mode, to the current regulation mode and the current regulator automatically resets the reference to control the power stage to provide a constant current of a lower value through the load. The system can be used to supply current to coils of injector valves in a fuel injection system, and may include two power stages for supplying current to two banks of coils. The regulator system is switched from one power stage to the other during successive 180° rotary positions of the engine for both stages.

Generator with multiple voltage regulators

Abstract: A solid-state series regulator is disclosed which controls the output of one phase of a multiple output three-phase alternator, whose remaining two phases have their output controlled by a solid-state regulator which varies the current to a rotating field exciting the alternator. The alternator is preferably used to charge two standard batteries, the main battery being charged by the two cooperating phases of the alternator whose output is controlled by the regulator for the field, while the auxiliary battery is charged by the third separate phase regulated by the solid-state series regulator. The two batteries are connected in series and connected to loads requiring different voltages.

Power output accessory unit

Abstract: An accessory unit for use with an engine powered vehicle having a conventional electrical system including a battery, voltage regulator and a dynamo of the alternator type having exposed AC and DC taps which in normal operation supplies DC power to the engine electrical system and, in some embodiments, to the electrical system of a host vehicle. A switch is provided to disconnect the dynamo from the engine electrical system. Also provided is a manually adjustable potentiometer through which the alternator output may be controlled. Circuit means feed the DC output of the dynamo to a welding terminal and the AC output of the dynamo to a step up transformer. A rectifying circuit rectifies the boosted AC output of the transformer and an outlet receptacle permits delivery of a 110-120 volt DC power output to power tools and like loads. Both the DC welding output terminals and the DC outlet receptacle have a common ground return through resistance means. Placement of a load across either the welding terminals or the DC outlet receptacle produces a voltage drop across the said resistance means, and this voltage drop is utilized to actuate a throttle control circuit including a control transistor, a power transistor and a solenoid type throttle control, functioning to increase the speed of the host vehicle engine when substantial load current is called for at either power output.

Circuit for generating a repeatable voltage as a function of temperature

Abstract: A circuit for producing a repeatable predetermined voltage as a function of temperature and includes a component having a known temperature coefficient characteristic. A transistor stage connected to the component multiplies the temperature coefficient. Linear as well as non-linear temperature characteristics can be multiplied by the circuit.

Variable flux-reset ferroresonant voltage regulator

Abstract: A thyristor controlled ferroresonant voltage regulator circuit is described, whereby the output voltage is highly regulated and adjustable. This is accomplished by means of a simple one-piece magnetic structure and a thyristor control cricuit which, in combination, provides a regulator circuit having terminal characteristics identical to the conventional ferroresonant regulator, with the additional features of having voltage adjust capability and the means for improving regulation characteristics by feedback circuit techniques.

Dual voltage system

Abstract: Two 12-volt batteries are connected in series across the output of a 24-volt charging system, and a DC to DC converter is connected between the output of the charging system and a junction between the batteries. To maintain equal voltages across both batteries, the voltage at the junction is compared with a reference voltage by a voltage regulator that is operatively connected with a DC to DC converter to maintain a regulated output therefrom to the junction.

Switch-mode voltage and current regulator

Abstract: An alternating current input to direct current output power supply providing a regulated constant voltage or constant current output and incorporating a switching-mode preregulator and a postregulator. Regulation is primarily obtained by means of a bidirectional switching element operated at a relatively low voltage and the alternating current voltage output from the switching element and an associated power transformer is applied to a rectifying voltage multiplier to produce a high voltage output. A series-pass output regulator, is controlled by negative feedback derived from the output circuitry and negative feedback from such regulator controls the switching element.

Dual voltage charging system

Abstract: First and second batteries are connected in series between the terminals of a vehicle starting motor. The DC output terminals of a DC generator are connected across the first battery and also across a voltage sensitive switch and the oscillator transformer input stage of a DC to DC converter. The rectifier output stage of the DC to DC converter is combined with a voltage regulator that is connected across a second battery. The voltage sensitive switch renders the input stage of the converter operative when the output of the the generator is greater than a first predetermined voltage and inoperative below. The voltage regulator maintains a second predetermined voltage across the second battery by rendering the output stage of the converter operative to charge the second battery when the voltage thereon is below the second voltage and inoperative above.

True rms to dc converters

Abstract: An apparatus for converting a complex AC voltage wave to an equivalent DC value which is a measure of its true RMS value and which may then be read on an accurate indicating device such as a digital voltmeter, incorporating thermal converters and operational amplifiers in a temperature-compensated configuration The apparatus maintains a portion of an unknown AC voltage wave, which is thermally converted into a DC voltage, substantially equal to a DC reference voltage A portion of a DC output voltage is also maintained substantially equal to the DC reference voltage Since the proportioning means for the complex AC voltage wave and the DC output voltage is the same, the true RMS value of the complex AC voltage wave is equal to the DC output voltage

Direct-current power supply system

Abstract: A plurality of voltage regulator circuits are connected to a battery for producing regulated positive and negative output voltages of different values. A warning circuit is provided for causing a light emitting diode to blink when the battery voltage falls below a first value. An automatic shutdown circuit is provided for disabling the regulator circuits when the battery voltage falls below a second and lower value. An overload circuit is provided for rapidly blowing a protective fuse when the output voltage of one of the regulator circuits exceeds a desired value.

Digital Analysis of Excitation Control for Interconnected Power Systems

Abstract: Excitation control by stabilizing signal taken from several locations in the system, together with the proper transfer function, has been investigated to satisfy the system stability from an overall performance view point, rather than one machine against an infinite bus. Several stabilizing signals have been tried from which the following signals have been found to have a great affect in increasing the damping: (1) a signal from the change of network voltage and taken from the far end, and (2) a signal from the change in the machine terminal frequency through a compensating network having a transfer function containing three zeros and three poles. The location of such signals greatly effects the system stability, and it is found that the signal taken from the change of frequency at a remote point of the network and applied to the voltage regulator of the machine under consideration has more effect in stabilizing the system. The station working with a leading power factor makes the stability rather critical, and stabilizing such stations greatly improves the system stability.

Current regulator with delayed turn-off

Abstract: A voltage regulator with delayed current turn-off characteristics particularly useful with capacitive loads and including a load current control transistor, control circuitry for the current control transistor, and load current sensing circuitry the control circuitry being responsive to excess load current and biasing the load current control transistor to limit current. Transistor circuitry is provided within the control circuitry whereby continued excess current for a predetermined period of time will remove the power supply by interrupting the current to the load.

Overvoltage protection of dc to dc converters using ferroresonance

Abstract: The frequency characteristic of a ferroresonant regulator is shown to have a critical jump frequency above which the output voltage of the regulator takes a sudden drop. A regulated voltage converter utilizes this discontinuity to provide automatic overvoltage protection. An inverter drives a ferroresonant regulator and a feedback loop controls the frequency of the inverter in response to output voltage. A short in the feedback loop drives the frequency above the critical jump frequency to provide automatic voltage limiting.

Energy pump voltage regulator

Abstract: A circuit for increasing and regulating the voltage appearing at the input terminals of a power supply. A plurality of cascaded stages are provided. Each stage comprises: an inductive energy storage device; a switching device; a control device; and a discharge path. Control signals, having a selectable sequential time relation therebetween, are provided to the stages so that energy discharged from adjacent stages is caused to overlap in time. The amount of overlap is adjustable and is dependent upon the sequential time relation between the control signals which is selected.

Voltage controlled chord organ

Abstract: An electronic chord organ, in which voltage controlled oscillators are each supplied with the same voltage, the voltage being selected by actuation of keys of an organ keyboard, and the currents supplied to the individual oscillators being selected to sound a musical chord. The voltage controlled oscillators each receive voltages from a resistive voltage divider via a voltage sample and hold circuit, key switches applying voltage from selected points along the voltage divider via diodes to a common bus, the bus controlling the frequencies of all the oscillators, and the diodes serving to render only one key switch operable to apply voltage to the bus when plural ones of the key switches are simultaneously closed.

Overvoltage protection arrangement for power converters

Abstract: A controlled rectifier is connected in multiple across a nonregulated d.c. source which supplies operating energy to a transistorized d.c. to d.c. converter apparatus. Also connected across the source, oppositely poled, is a Zener diode with a reverse breakdown voltage greater than the normal source voltage but less than the breakdown potential which damages the transistors in the voltage regulator portion of the converter. A gating signal is applied to the controlled rectifier if Zener diode breakdown occurs due to a sustained increase in source voltage. A fuse interrupts the leads from the source when the resulting high current flows through the controlled rectifier and protects the transistors from damage. Another Zener diode is connected, with reverse polarity, across the connections between the regulator and inverter portions of the converter. Its reverse breakdown voltage is selected just above the normal regulated output voltage, but low enough to protect the transistors in the inverter circuits. This second Zener diode also supplies a gating signal to the controlled rectifier, if breakdown occurs, to protect against an overvoltage due to a fault in the regulator circuits. Additional Zener diodes may be used in similar manner to protect against overvoltage faults at other points in the converter apparatus.

Static control for step voltage regulator

Abstract: A control for a step voltage regulator having a reversible motor for actuating a tap changer switch to vary the regulator output voltage when a ''''raise'''' or a ''''lower'''' signal respectively is applied thereto, includes a potential sensing transformer for deriving a sample DC voltage proportional to the regulator output voltage, a zener diode for deriving a DC reference voltage of opposite polarity to said sample voltage, a summing operational amplifier which receives the sample and the reference voltages on its inverting input, a polarity and magnitude sensor including a pair of oppositely-poled, serially-arranged zener diodes coupled to the output of the summing amplifier and a NPN and PNP transistor having commoned bases coupled to the pair of zener diodes for deriving raise and lower signals when the output voltage from the summing amplifier is of predetermined magnitude and of opposite polarity, and a rheostat for varying the gain of the summing amplifier to thereby regulate the voltage bandwidth within which the output voltage of the step regulator is maintained.

Power sequencing control circuit

Abstract: Current applied to a load by means of a first voltage is disabled by control means in response to a change of a second voltage by a predetermined value. The control means is powered by the first voltage and includes two stages, a first for detecting a change of the second voltage and the second responsive to such change and powered by the first voltage for generating a signal for disabling the current applied to the load.

Dual-voltage feedback comparator for simultaneously monitoring a positive and negative voltage

Abstract: In this invention a positive voltage V1 and a negative voltage V2 are simultaneously monitored by two voltage comparators, which compare voltages on two potentiometers with a standard reference voltage. The potentiometers are tied between constant current loops, each comprising a zener diode, a resistance, and a transistor. When either of the voltages changes the collector of the appropriate transistor takes up the voltage, and thus the potentiometers shift in their potential in accordance with the change of the monitored voltages. These changes in potential are transferred to the comparators which switch their output from a logical zero to a logical one whenever the voltages they are monitoring vary by more than a selected value from a preselected value.

Reference voltage generator and regulator

Abstract: A circuit which is utilized to produce a reference voltage that is substantially independent of changes in the supply line voltage and in temperature and which produces a regulated output voltage as a function of the reference voltage.

Display baseline stabilization circuit

Abstract: A display baseline stabilization circuit is described which automatically compensates for differences in the quiescent DC voltage levels of input signals being displayed on a cathode ray tube or other display device, to maintain the baseline displays of such levels in the same vertical position The stabilization circuit includes a sampling system for sampling the quiescent voltage level of such input signals and comparator means for comparing the sample output voltage with a DC reference voltage corresponding to the desired vertical position of the baseline to produce a difference voltage The difference voltage is stored in a gated correction memory whose output is a baseline correction voltage feedback applied to the output of the sampling gate for subtraction of the correction voltage from the sample output signal transmitted to the display device The stabilization circuit may be employed in a time domain reflectometer apparatus in which a test pulse generator, such as a tunnel diode, applies step voltage input pulses to one end of a transmission line under test to measure the value and location of any discontinuation in the characteristic impedance of such line The other end of such transmission line is selectively terminated in an open circuit, a short circuit, or a finite resistance so that the quiescent DC voltage level of the step voltage input signal varies with such termination changes and tends to cause the display baseline on the cathode ray tube to move vertically However, this movement of the baseline is prevented by the stabilization circuit

Voltage regulators for use in battery charging systems

Abstract: A voltage regulator is disclosed for varying the output of a generator of a road vehicle by changing the current flow in its field winding. The voltage regulator device includes, as is common, a Zener diode or equivalent break-down device which, as known, conducts at a predetermined battery voltage, and serves to render a transistor conductive, which transistor, when rendered conductive, acts through further components to reduce the current flow in the field winding. In systems of this type it is commonplace to provide for temperature compensation by providing a thermistor or equivalent device in the circuit. Such device, in a known manner, serves to compensate for changes in battery temperature, as well as for the changes in temperature coefficient of the Zener diode and the transistor so utilized. However, in accordance with the instant invention, such temperature compensation is achieved by means of a simple impedance network interconnecting the Zener diode or equivalent device and the transistor, such impedance network, in effect, serving to multiply the net negative inherent temperature characteristics of the transistor by a selected amount to compensate for the net positive temperature coefficient of the Zener diode, the resultant characteristics of the voltage regulator circuit with respect to temperature being desirably negative or, at least, zero. In the specific preferred embodiment, a resistor is disposed across the base-emitter of the transistor, and another resistor is disposed in series circuit with the Zener diode. The ratio of these two resistors substantially defines a multiplication factor which enhances the net negative temperature coefficient of the transistor and serves to overcome the net positive temperature coefficient of the Zener diode.

Power output unit and method for delivering constant frequency, constant voltage ac power

Abstract: An accessory unit for use with an engine powered vehicle having a conventional electrical system including a battery, voltage regulator and a dynamo which in normal operation supplies DC power to the vehicle electrical system, including switches adapted to isolate the dynamo from the vehicle electrical system, and means for boosting the DC voltage dynamo output and converting it to a constant frequency AC voltage. An outlet receptacle is provided to accept jacks from power tools, appliances or the like having constant frequency AC voltage power requirements. The outlet receptacle voltage is monitored and the dynamo field current is adjusted in response to variations therein to control the dynamo voltage and amperage input to the unit. In another embodiment of the invention, a secondary coil is provided on the transformer along with conventional rectifying means to step down and rectify the increased AC output voltage. Voltage regulator means is provided to sense variations in this low voltage DC secondary output and control the dynamo field current in response to variations therein to maintain a desired dynamo output voltage and amperage. Additionally, the vehicle battery may be charged by an output from the rectified low voltage secondary output of the transformer.

Precision voltage regulator

Abstract: A voltage regulator providing a very stable output voltage with respect to time, temperature, and load, by supplying a stable, constant current to a reference diode. The regulator has an operational amplifier, and a plurality of zener diodes coupled thereto.

The Derivation and Application of Design Equations for Ferroresonant Voltage Regulators and Regulated Rectifiers

Abstract: Design equations for the most commonly used ferro- resonant regulators and regulated rectifiers are derived. Expressions relating the physical size of the components and the short circuit characteristic of the circuit to the output power, frequency, input power factor, and voltage levels are developed. From these expres- sions, design equations that optimize the design are obtained and specific component values are recommended. For regulated rectifiers, the design of the filter and the effect of the filter on the design of the basic regulator are discussed. The effect of deviating from the recommended values and the effects of nonlinearities not considered in the derivations are discussed. Design examples and data are presented.

Stop motion device with selective indicator

Abstract: A stop motion system for multi-thread textile machines includes a number of thread slack-detection switches disposed in parallel and each having an indicator lamp and a diode in series with the switch. A voltage source and a stop motion relay are in series with the switches and the voltage source produces a potential through any closed switch and its associated lamp and diode greater than the breakover voltage for the diode. Each diode, however, is a four layer diode so that its sustaining voltage is very much less than its breakover voltage. In this way, the first diode to conduct reduces the potential available across any of the other diodes to the sustaining voltage so that only the first detector circuit activated will be effective to provide an indication of malfunction.