Showing papers on "Voltage regulation published in 1970"

Control circuit for providing regulated current to lamp load

Abstract: Control circuit for gaseous discharge lamps including a variable frequency inverter for driving a high-reactance transformer having a first capacitor in the transformer secondary tuned to a harmonic of the supply voltage to provide ignition voltage for the lamps, and a second capacitor in near series resonance with the fundamental frequency of the supply voltage to provide series impedance at the fundamental frequency for stable operation after ignition, and lamp current sensing means for providing a feedback signal to a variable reference comparator circuit which adjusts the frequency output of the inverter to provide regulated lamp current for changes in input voltage and lamp voltage.

Electrical regulator apparatus including a zero temperature coefficient voltage reference circuit

Abstract: An integrated circuit regulator including a temperature stable constant voltage reference wherein the negative temperature coefficient of the base-to-emitter voltage a first transistor in conjunction with the positive temperature coefficient of the base-to-emitter voltage differential between two additional transistors operating at different current densities is used to achieve a zero temperature coefficient reference potential. The constant voltage reference is combined with a voltage follower and provides a source of constant current which is passed through an external variable resistance to develop a selectable and predictable adjustment voltage for driving the voltage follower so as to cause an unregulated input voltage applied thereto to be regulated at an output terminal.

Wide band boost regulator power supply

Abstract: A power supply which, in one embodiment, provides to a load a relatively constant DC (direct current) output voltage at a voltage level equal to or greater than that being supplied from a variable DC voltage source. The power supply includes a first switching circuit controlled by a voltage sensing circuit to allow energy to be transferred from a current storage device to a voltage storage device to maintain the amplitude of the output voltage within predetermined levels, and also includes a second switching circuit controlled by a current sensing circuit to allow the amplitude of circuit to be maintained within predetermined limits.

A feedback-controlled ferroresonant voltage regulator

Abstract: A new regulated rectifier which combines a ferroresonant regulator with a simple control circuit is described herein. The voltage regulating function normally provided in a ferroresonant regulator by the saturating core is provided by the control circuit in this new regulated rectifier. The control circuit provides regulation by varying the amplitude of the alternating voltage feeding the rectifier and filter. By incorporating feedback into the control circuit, regulation of better than ±1/2 percent for line, load, frequency, and temperature changes can easily be attained. The new feedback-controlled circuit retains many desirable properties of conventional ferroresonant regulators such as half-cycle transient response, good input power factor, ideal output waveform for rectification and filtering, high efficiency, short circuit protection, and suppression of input voltage spikes. Additional features are level set, improved efficiency, lower stray magnetic fields than observed with conventional ferroresonant regulators, and, primarily, precision regulation. Data on an 800-watt regulated rectifier employing the new circuit are also presented.

Dual voltage power system for use with vehicle alternators and the like

Abstract: There is disclosed herein a dual voltage power unit for use in automobiles, campers, and the like for normally supplying the relatively low DC voltage from an alternator to a storage battery and other electrical devices of the vehicle and for supplying a higher voltage, such as 115 volts, for external usage such as for lighting, emergency power, and so forth. Several circuits are disclosed herein for providing a dual output DC voltage, or for providing a low DC voltage and a higher AC voltage at 60 hertz. The system includes a rectifier circuit coupled with the output of an alternator for normally providing the usual automotive DC voltage, such as 14.5 volts. A load sensor and control circuit are provided for sensing the demand for the higher voltage and for controlling rectifier circuits to supply the same.

Amplifier protection circuit

Abstract: A protection circuit for a transmitter amplifier is provided which senses the forward power level and develops a first voltage which is compared with a reference voltage to provide a control voltage which controls the power developed by the transmitter amplifier. Increase in the forward power level is detected changing the control voltage to cause a reduction in the forward power developed by the transmitter amplifier. Decrease in forward power level is detected changing the control voltage to cause an increase in forward power developed by the transmitter amplifier. Reflected power is sensed developing a second voltage which causes a reduction in reference voltage when reflected power exceeds a predetermined level. Reduction of the reference voltage also changes the control voltage to reduce the forward power of the transmitter amplifier to a safe level. An increase in transmitter amplifier temperature beyond a predetermined level is sensed causing a reduction in the reference voltage to change the control voltage thereby reducing the power of the transmitter amplifier to a safe level.

High level non-contacting dynamic voltage follower for voltage measurement of electrostatically charged surfaces

Abstract: A wide band voltage follower circuit for voltage measurement of electrostatically charged surfaces through the use of a probe having a capacitor detector arranged in spaced and non-contacting manner with the surface under measurement to detect the unknown surface voltage thereof, the probe having a cable connected to the output of the capacitor detector. An ultra high impedance low level voltage follower is connected to the capacitor detector output through the cable, and shield means driven by the output of the ultra high impedance low level voltage follower are employed to shield the latter, the cable, and the probe, thereby minimizing the effective input capacitance of the ultra high impedance low level voltage follower. A high level voltage follower is connected to the output of the ultra high impedance low level voltage follower, and a floating power supply is connected to power the ultra high impedance low level voltage follower. The power supply is bootstrapped with the latter by the high level voltage follower through the connection of the common line of the floating power supply to the output of the high level voltage follower. The output of the high level voltage follower is connected to a peak-to-peak detector to derive an output voltage whose D.C. voltage is equal to the D.C. voltage of the surface under measurement.

Related power supply

Abstract: A solid-state high-voltage regulation circuit for devices such as television receivers which incorporate a flyback transformer. Voltage changes across the transformer secondary winding are compared to a stable reference, and any difference is amplified and applied to control the flow of current to the transformer primary coil. The output voltage is thus maintained essentially constant.

Method and apparatus for the uninterrupted switching of at least one alternating-current consumer of a voltage supply source or current supply source to a different voltage supply source or current supply source

Abstract: A method and apparatus for switching at least one alternating-current load from one power supply, such as a voltage supply or current supply, to another power supply, such as a voltage supply or current supply, upon the appearance of an error in the power supply coupled with the load. Each power supply possesses electronic switch means at the connection conductors to the load. An error detector determines the deviations of the waveshape of the load voltage from a predetermined waveshape of a reference voltage for a successive time interval, and upon exceeding an adjustable maximum deviation value, the electronic switch means are actuated for coupling the first-mentioned power supply to the other power supply.

High-low voltage level sensor

Abstract: High- and low-level voltages are derived from a voltage to be monitored and applied, along with a reference voltage, to the input terminals of a pair of comparators. An over voltage condition causes the comparator monitoring the low-level voltage to be energized, while an under voltage condition results in the energization of the comparator monitoring the higher level voltage. The signal then produced by the comparators is used to energize an alarm device.

Bootstrap driver with feedback control circuit

Abstract: A control circuit detects a minimum output voltage level and feeds back that voltage level to boost the voltage across a capacitor connected between the control circuit and the gate electrode of a load-driving field effect transistor. The voltage on the gate electrode of the transistor is boosted to a voltage in excess of the threshold voltage of the transistor plus the minimum required output voltage.

Optimal Static Capacitor Allocation by Discrete Programming: Development of Theory

Abstract: Shunt static capacitor banks are frequently an economical means of maintaining voltage levels under conditions of heavy load or transformer, line, and generation outages. This paper treats the allocation of capacitor banks as a discrete programming problem in which the objective is to minimize capital outlay for the banks required to control voltages under all anticipated contingencies.

Dual battery charger having dual output

Abstract: First and second batteries are connected in series between a point of constant reference potential and the output terminal of a first full-wave bridge rectifier. The output terminal of a second full-wave bridge rectifier comprising silicon-controlled rectifiers (SCR) is connected to a junction between the batteries. The respective legs of the first and second rectifiers are each connected to the same output winding of the stator of an alternator. A first voltage detector responsive to the voltage across the first and second terminals causes the SCR''s to be nonconductive when the voltage across the first and second terminals is less than a first predetermined voltage. A second voltage detector controls the current through the field winding of the alternator in response to the voltage at the junction between the batteries to maintain a second predetermined voltage thereat. The drop in current and therefore voltage at the junction occurring an instant after the SCR''s are rendered nonconductive causes the second voltage detector to increase the current and voltage at the first output to increase by an amount sufficient to reestablish the second predetermined voltage at the junction.

Power control timing circuits with power line compensation

Abstract: Line voltage compensation is provided by a power control timing circuit for gated power control devices, which utilizes a negative resistance impedance for establishing the timing capacitor charging voltage, thereby determining the conduction angle to maintain power applied to a load relatively constant, notwithstanding fluctuations in the power line voltage.

Apparatus for controlling power distribution in substation

Abstract: An apparatus for controlling voltage flicker in power distribution in a substation, comprising a synchronous condenser, a field adjuster for the synchronous condenser and a compensation circuit, said apparatus being adapted to compensate the distribution voltage flicker due to a large load variation in said substation and being able to adjust a predetermined distribution voltage within an allowable range. The compensation circuit may include an incomplete differential circuit and means for feeding the sum of the products respectively obtained by multiplying the variable part of the respective power of each load and its respective weight coefficient.

Temperature stable integrated oscillator

Abstract: A temperature stable integrated oscillator has a control loop including a flip-flop, a series resistor-capacitor timing circuit, reference voltage means and a comparator. The comparator compares the reference voltages to the voltage swing across the capacitor to actuate the flip-flop and thereby provide the oscillator output frequency. Temperature stability is provided by making both the voltage swing across the flip-flop and the reference voltage proportional to the difference between the power supply voltage and the base emitter drop of associated integrated transistors.

Voltage supply apparatus for applying a direct current to a periodically varying load

Abstract: A voltage supply apparatus for feeding a periodically varying load provided with a safety circuit wherein a rectified voltage originating from the mains is converted into an output direct voltage by means of a chopper. The switching frequency of the chopper is at least equal to that of the load. The apparatus comprises measuring means by which the chopper is stopped in case of overload, while a smoothing capacitor having a comparatively low capacitance is arranged parallel to the load. After an overload the output voltage is slowly built up. For this purpose the ratio between the active period of the chopper and the period of the switching frequency must become small ( about 0.1). This is achieved by using a thyristor as a pulse duration modulator and by having a capacitor of high value shunt a reference voltage element in the comparison circuit of the chopper. The coil of the chopper constitutes the primary winding of a transformer secondary windings of which drive diodes which conduct simultaneously with the efficiency diode of the chopper so as to generate further direct voltages. In a preferred embodiment the apparatus feeds the line deflection circuit of a picture display device wherein the switching frequency is the line frequency and wherein the output voltage can be modulated by a parabola voltage of field frequency for the purpose of correcting the East-Westpincushion distortion.

Motor speed control with transformer feedback means

Abstract: A power supply circuit including a Triac for controlling the initiation of current flow to the load during each half-cycle. Firing of the Triac is directly controlled by a diac, and during each half-cycle the firing of the diac is controlled by a timing capacitor which is charged first in one direction and then in the other by current flowing from the alternating current source. In one form of the circuit the exact firing point of the diac (and hence of the Triac) is also influenced by a feedback transformer which derives a regenerative feedback voltage from the current flowing through the Triac, and which operates when the Triac current increases to advance the point at which the Triac fires. In another form of the circuit a regenerative feedback voltage is achieved without the use of a transformer, using Zener diodes for line voltage regulation and a number of resistors and capacitors suitably connected in the circuit. The circuits are illustrated as supplying current to an electric motor, which requires an increase in operating voltage in order to maintain the motor speed constant when the mechanical load on the motor increases. The purpose of the above abstract is to provide a non-legal technical statement of the disclosure of the contents of the instant patent application and thus serve as a searching-scanning tool for scientists, engineers and researchers. Accordingly, this abstract is not intended to be used in understanding or otherwise comprehending the principles of the present invention hereinafter described in detail, nor is it intended to be used in interpreting or in any way limiting the scope or fair meaning of the claims appended hereto.

Voltage regulator for permanent magnet generators

Abstract: A voltage regulator circuit having an input terminal for connection to the output of a permanent magnet generator which develops a voltage at its output variable in frequency and amplitude in response to the speed of rotation of the generator. A current control device is arranged to switchably connect the output of the generator to a desired load in response to trigger pulses which are generated at desired phase angles during each half cycle of a given polarity of the applied voltage. The output of the voltage regulator may be free of an external power source, and in such case, means are provided to always establish at least a minimum current flow at the output of the regulator during no load conditions to effect continuous operation of the regulator for all voltage values at the output of the generator.

Voltage monitoring device having a pair of differential amplifiers

Abstract: The output of an electrical power source is continuously monitored by voltage comparing circuits to which a reference voltage is applied through a low impedance driver. The reference voltage is compared with adjustably reduced values of the variable voltage of the source being continuously sampled to establish upper and lower voltage limits. When these limits are exceeded, a resettable alarm circuit is triggered into operation.

Non-linear exciter controller for power system damping

Abstract: Damping of power system oscillations is accomplished by additionally directing exciter-voltage regulation for individual system generators in accordance with variations in the derivative of reactive power generated by a generator. Signal voltage proportional to reactive power in generator output is differentiated to develop a signal voltage representing rate of change of reactive power variations which is applicable as an auxiliary input for determining operational control of excitervoltage regulation of the generator. Control for suppressing system oscillations is continuous as long as generator bus voltage does not exceed pre-set upper and lower voltage limits.

Connectionless electrical meter for measuring voltage or power factor

Abstract: A connectionless electrical meter is described which is capable of measuring the power carried by a conductor at a voltage with respect to ground, or the power factor thereof, without the necessity for any ohmic connection between the meter and the circuit being measured. Conductor current is measured by magnetic induction with an openable transformer core which surrounds the conductor. A signal in-phase with the voltage is obtained by electrostatic induction. In certain embodiments of the invention, a unique voltage probe is used for obtaining a signal proportional to the conductor voltage. Apparatus described herein employing such voltage probe is additionally useful for measurement of voltage independently of power or power factor.

Regenerative voltage regulators

Abstract: Regenerative power switches for use in semiconductor circuits such as in voltage regulators having a DC or low-frequency output controlled by a high-frequency pulse input. The circuits are designed to minimize the power dissipation in the regulator circuit and to minimize the number of components, particularly inductive components required. The regulator circuit having a negative common uses a feedback voltage from a secondary coil on the output filter choke to create a voltage exceeding the supply voltage, which is used without rectification thereof to force a series transistor into saturation during the ON portion of the cycle, thereby minimizing the voltage drop across that transistor and maximizing power output capability of the voltage regulator or amplifier. The regulator circuit having a positive common uses a feedback voltage from a top on the output filter choke winding to force a series transistor into saturation. The use of the tap minimizes the power dissipation in the regulator during the ON portion of the cycle and further aids in a fast and complete turnoff.

Protective system for electrical discharge machining power supply circuit

Abstract: A circuit is provided to sense an electrical parameter of the gap to determine whether electrical discharge machining is progressing properly. A gap parameter such as gap voltage or a voltage directly related to such parameter is compared to a variable reference voltage to provide reduction or interruption of machining power pulses. A control is included which conjointly controls frequency of machining pulses and the magnitude of the variable reference voltage.

High voltage regulation circuit for television receiver

Abstract: A high voltage regulation circuit in a high voltage power supply circuit for a television receiver in which a transistorized horizontal deflection circuit is connected to the primary winding of a flyback transformer is disclosed, said regulation circuit comprising a diode and a capacitor connected to the primary winding, and means for controlling the amount of discharge from said capacitor depending upon the current load change in the high voltage power supply circuit mainly during a tract period, whereby the variation of high voltage due to the load variation in the high voltage power supply circuit is prevented and stabilized high voltage is produced.

Control circuit for inductive loads

Abstract: For energizing an inductive load with a maximum current of brief duration followed by a steady current, less than the maximum, the inductive load is initially connected, by means of an amplifier switch, across a voltage source of relatively high-output voltage and subsequently connected, by means of another amplifier switch, across a voltage source of relatively low-output voltage. Trigger circuitry is operable to apply an input pulse of predetermined duration to the amplifier switch associated with the voltage source of high-output voltage and simultaneously trigger a delay circuit arranged to apply an input voltage to the amplifier switch associated with the source of low voltage. Respective diodes connect a common point the outputs of the respective amplifier switches, the common point and a point at a reference potential provide respective first and second connections to the inductive load.

Process controller with gain-changing circuitry

Abstract: A process controller having gain-changing circuitry in a negative feedback loop for a controller amplifier for changing the controller gain as a function of controller output. A pair of resistors form a voltage divided connected between the output and a variable voltage source. The variable voltage source is adjusted to the desired value of the output at which the controller is to change gain. The voltage at the junction of the resistors is introduced to the amplifier input through a feedback impedance. A switching circuit is connected between the variable voltage source and the voltage divider. When the output voltage is less than the adjustable variable voltage, the switch is open and a first proportion of the output voltage is introduced to the feedback impedance. When the output voltage is greater than the adjusted variable voltage, the switch is closed causing the voltage divider to be conductive, thereby introducing a second proportion of the output voltage to the feedback impedance.

Automatic voltage regulating system for a dc load

Abstract: For automatic voltage regulation for a DC load, fed from an AC source via a three-terminal thyristor or a silicon-controlled rectifier, a constant-voltage element is connected in parallel to the AC source via a nonvariable resistance, and a capacitor is provided which is charged, via a variable resistance, with a voltage corresponding to a difference between the constant voltage of the aforesaid constant-voltage element and the voltage of the DC load, the voltage of said capacitor being impressed to the control terminals of the three-terminal thyristor, i.e., the gate and cathode terminals of the silicon-controlled rectifier, via a threshold-value element (e.g., a Shockley diode) that becomes conductive when the voltage of the capacitor reaches a predetermined threshold value.

Battery charging current and termination control circuitry

Abstract: To reduce the charging current in the latter part of a charge, an automatic battery-charging apparatus includes means for comparing a sample voltage depending on the battery voltage while on charge, with a reference voltage which is progressively increased throughout the charge, and using a function of the difference to control the charging current. Thus if the battery voltage and sample voltage increase more rapidly than the reference voltage, the charging current is reduced and vice versa. The reference voltage may be supplied by a motor-driven potentiometer, or by a progressivley charged capacitor. The duration of the charge is also controlled so that a phase of the charge is terminated when the value or rate of change of the sample voltage, having exceeded that of the reference voltage, then falls below it.

Circuit arrangement for transforming the voltage of a dc voltage source into a pulsating voltage

Abstract: A circuit arrangement for supplying a load, e.g. an X-ray tube, with a pulsating voltage by means of a DC voltage source connected in series with the load and a controllable rectifier, which is extinguished by means of the charge on a commutating capacitor, which, via a current transformer, is charged by the leading edges of the load current, and the discharge of which is controlled, via a timing device, by the voltage across the commutating capacitor. Means may be provided for reducing the time constant of the timing device when the load current exceeds a given value.