Showing papers on "Voltage regulator published in 1973"

A precision reference voltage source

Abstract: With increasing temperature the base-emitter voltage of a transistor with a constant current decreases, while the difference in base-emitter voltages of two identical (integrated) transistors having a constant current ratio increases. From the sum of the two voltages a nearly temperature- independent output voltage is obtained if this sum equals the gap voltage of silicon. A reference voltage source of 10 V based on the principle is described. The reference part of the circuit is an integrated circuit, and thin-film resistors with a small relative temperature coefficient are used. An operational amplifier and a few resistors and capacitors complete the circuit. The source has a parabolic temperature characteristic and the temperature peak can be controlled by resistor adjustment. A change of /spl plusmn/10 K in respect of the peak temperature causes an output voltage change of -250 /spl mu/V, while a change of /spl plusmn/30 K causes a change of -2.2 mV. A long-term stability of 10 ppm/month was measured. The circuit can compete with the best available Zener diode sources, and has the added advantage that practically no selection is necessary.

Dual battery electrical system for internal combustion engine

Abstract: In a dual battery system for an internal combustion engine, as used in a vehicle or the like, wherein an auxiliary battery is connected in series with a service battery to provide a high battery voltage for a starter circuit, a charging means is provided for charging both the service battery and the auxiliary battery without changing their series connection. This charging means comprises an alternator, rectifier and voltage regulator for charging the service battery and an additional rectifier connected to the alternator through an isolation transformer for charging the auxiliary battery.

Electric power plant for land vehicles

Abstract: An electric power plant for a land vehicle which includes: an electric motor; two alternators driven by the motor; a voltage regulator for the alternators; and two sets of batteries charged alternately through the regulator. The battery that is not being charged energizes the motor. The alternators are on the drive axle of the vehicle.

Power supply keep alive system

Abstract: A power supply system comprising a plurality of parallel connected voltage regulators, each regulator having a voltage control loop. Each voltage regulator is provided with a circuit which increases the reference voltage supplied to the voltage control loop so that the control loop of each regulator is prevented from being cut off during standby operation.

Temperature compensated voltage regulator having beta compensating means

Abstract: A temperature compensated voltage regulator circuit having a resistive impedance of a particular value disposed in the base circuit of the first of two cascaded transistor elements to provide compensation for possible beta ( Beta ) variations incurred as a result of process variables.

Semiconductor pressure transducer employing novel temperature compensation means

Abstract: A semiconductor pressure transducer having a cavity with one thin wall diaphragm on which a piezoresistive bridge is formed of four resistors diffused into the thin wall semiconductor diaphragm and coupled together as a Wheatstone bridge, a voltage regulator including a zener diode coupled to the bridge, and a pair of nVBE circuits coupled to the bridge and the regulator circuit for temperature compensation of the bridge and regulators over the operating temperature range, each of said nVBE circuits comprising a transistor and two associated resistors connected so as to provide an irrational number of VBE voltage drops for temperature compensation.

Power inverter circuit

Abstract: A power supply is provided which is capable of operation from either of two power sources, such as on normal power from the usual alternating-current mains, or emergency power from a standby battery; and which will automatically switch from one source to another as the need arises. The power supply includes a transformer having at least two primary windings, and first and second input circuits respectively connected to the two primary windings and to the two sources. The preferred source will be selected by the power supply so long as its voltage is equal to or greater than the voltage of the secondary source.

Temperature responsive battery charging circuit

Abstract: A battery charging circuit for use in aircraft wherein a voltage-regulated alternator is employed to maintain a nickel cadmium battery charged. A temperature-dependent resistance element thermally coupled to the battery provides a reference voltage against which battery terminal voltage is compared. When the terminal voltage falls below the reference voltage application of sensing voltage to the alternator voltage regulator is interrupted, causing full charging current to be applied to the battery. When the terminal voltage exceeds the reference voltage, sensing voltage is reapplied to reduce charging current. The alternator switches between maximum and minimum charging efforts to maintain a voltage level dictated by the battery temperature.

Voltage monitoring controlling and protecting apparatus employing programmable unijunction transistor

Abstract: A PUT circuit compares a zener reference voltage with the voltage of an electronic flash storage capacitor, and starts and stops a battery powered d.c. to d.c. converter oscillator, which charges the capacitor, as necessary to maintain the capacitor voltage within desired limits. A zener diode in the PUT cathode circuit provides the desired hysteresis. A second PUT circuit compares a second zener reference voltage with the battery voltage, and stops the oscillator when the battery voltage drops to a predetermined minimum value.

Compensated electronic voltage source

Abstract: A voltage and temperature stable integrated voltage regulator circuit offsets the negative temperature coefficient of the baseto-emitter voltage of one transistor with a positive temperature coefficient derived from the base-to-emitter voltage differential Delta VBE between a pair of additional transistors Other transistors are used to produce a pair of regulated stable output voltages, each having a predetermined voltage with respect to a different one of the two input voltage terminals across which the regulator circuit is connected Circuit components are provided to cause the two output voltages to be voltage and temperature stable or to have a predetermined controllable temperature coefficient

Voltage regulator system for use with fuel cell battery

Abstract: Intermittent operation of a pump feeding fuel to the battery is controlled by circuits which produce pump operation cycles at intervals determined by energy used in the load circuit as well as additional cycles if the voltage falls below a fixed limit. Compensation for the drop in concentration of the fuel as the result of recirculation of partly spent fuel is provided by lengthening the pump operation cycles or making them more frequent with respect to power energy consumption in the load, or both.

Thick-film voltage regulator for three-phase alternators

Abstract: A thick-film voltage regulator for the electrical system of an automobile or the like incorporates a housing formed of heatconductive material with cooling ribs, and an encapsulated portion through which conductors pass for interconnection with other components of the electrical system. The regulator control circuit is a thick-film hybrid circuit formed on an insulating substrate and having burned-in conductor paths and resistors with discrete capacitors and semiconductors being connected thereto. A zener diode is incorporated for overvoltage protection on a separate metallic substrate mounted adjacent to the insulating substrate, and both substrates are supported on the housing in good heat-conducting relationship therewith.

Voltage regulator for a direct current power supply

Abstract: Unregulated direct current is supplied to output terminals through the emitter-collector path of a transistor that is switched on and off by a bistable multivibrator. The multivibrator is periodically set by periodically recurring set pulses to turn the transistor on and supply direct current. The multivibrator is reset by a voltage sensing circuit which produces a reset pulse to turn the transistor off in response to the voltage at the output terminals reaching a selected magnitude.

Direct current voltage regulator

Abstract: Improved regulation of direct current voltage from an unstable voltage source through a transitor series regulator to a load is provided by a lockout circuit that prevents current flow through the series regulator when the source voltage is removed from the lockout circuit, by a current limiter circuit that controls the series regulator as a function of current supplied to a load, and by a current cutoff circuit that prevents current flow through the series regulator when the output voltage falls below a selected magnitude.

ASDTIC control and standardized interface circuits applied to buck, parallel and buck-boost dc to dc power converters

Abstract: Versatile standardized pulse modulation nondissipatively regulated control signal processing circuits were applied to three most commonly used dc to dc power converter configurations: (1) the series switching buck-regulator, (2) the pulse modulated parallel inverter, and (3) the buck-boost converter. The unique control concept and the commonality of control functions for all switching regulators have resulted in improved static and dynamic performance and control circuit standardization. New power-circuit technology was also applied to enhance reliability and to achieve optimum weight and efficiency.

Bias transformer for dual voltage input off-line converters

Abstract: In a dual voltage input AC to DC converter, the main DC voltage output is generated by a dual mode rectifier circuit, and an auxiliary AC voltage output is generated by a bias transformer circuit connected to the dual mode rectifier circuit. Though the AC to DC converter is capable of operating from dual input line voltages, both the main DC output voltage and the auxiliary AC output voltage remain constant and are independent of which one of the line voltages is input to the circuit.

Switching voltage regulator with optical coupling

Abstract: An improved voltage regulator has a transistor connected to switch on and off the current to the load with a variable waveform that establishes the effective current level. A voltage detector circuit adjusts the regulated current level to the level required to maintain the selected load voltage.

Reference voltage compensation for zener diode regulation circuit

Abstract: A circuit is disclosed for providing a constant regulated voltage to a load in conjunction with a first stage zener diode regulation circuit. The circuit compensates for regulated voltage variations incident to zener diode internal resistance by applying the zener diode regulation voltage to a voltage divider which goes to ground and using the voltage differential between the intermediate junction of the voltage divider resistances and the anode of the zener diode and by further communicating the anode of the zener diode to ground through an additional, compensating, resistance. The value of this resistance may be determined by multiplying the internal resistance of the zener diode by the ratio of the resistance of the voltage divider from the intermediate junction to ground divided by the resistance from the intermediate junction to the cathode of the zener diode.

Dual battery charging generator

Abstract: A battery charging generator which is capable of charging two series connected batteries in a motor vehicle electrical system where the series connected batteries are used to energize the cranking motor of a motor vehicle. The generator is of the alternating current type and has first and second three-phase full-wave bridge rectifier units built into the end frame of the generator each of which is capable of supplying charging current to one of the batteries. The generator has a built-in transistor voltage regulator which senses the voltage applied to the main battery of the system by the first bridge rectifier and which regulates the output voltage of the generator to a predetermined value. The second bridge rectifier supplies charging current to an auxiliary battery and is connected with the stator winding of the alternating current generator by means of a three-phase transformer. The transformer, like the bridge rectifiers, is built into the end frame of the generator and isolates the two bridge rectifiers of the system. The generator is arranged with a 12 volt and a 24 volt output terminal which only need be connected directly to the batteries when installing a generator on a motor vehicle.

Power supply over voltage protection system

Abstract: A power supply system is disclosed having a plurality of voltage regulator circuits connected in parallel with each other between a source of unregulated voltage and a load. Each of the voltage regulators includes an over voltage protection circuit whereby a particular regulator is taken out of service when the current in that regulator exceeds a certain level and the voltage across the load is at a first level. The regulator is not taken out of service when the current through the regulator is below the certain level and the voltage across the load is above the first level but below a second, higher, level.

Voltage regulator with controlled current

Abstract: A voltage regulating system for AC generators including a three phase current boost and a voltage responsive control circuit having a full converter type output stage. The three phase boost circuit and the full converter output stage are connected in series with the field winding of the exciter. At high power output levels, the inverting capability of the full converter power stage is used to oppose the voltage generated by the current boost to prevent loss of control over the generator, by diverting excessive boost currents through a load means connected to the current boost circuit.

Series-parallel dual switching regulator for use with a variety of line voltages

Abstract: The power section of the switching regulator is divided into two identical parts. The two parts may be connected in series when a high value of power line voltage is used. The two parts are connected in parallel when a lower value of power line voltage is used. The same value of regulated output voltage may be obtained with either the series or the parallel connection.

Arc welder and combined auxiliary power unit and method of arc welding

Abstract: An arc welder is comprised of an inductor alternator, a variable voltage source for energizing the field of the alternator, a rectifier for rectifying the alterantor output, and an internal combustion engine or electric motor of suitable horsepower for driving the alternator. The welding current of the welder is controlled solely by varying the field excitation, and for various levels of field excitation the open circuit voltage remains substantially constant, the output voltage versus current characteristic is inherently such that within the range of welding voltages the current is substantially constant, and the voltage recovery time from short circuit is extremely rapid, thereby eliminating the need for auxiliary devices such as voltage and current regulators, series reactors and/or load control resistors. A switch means for selectively connecting the generating windings to the rectifier in either a delta or wye configuration and a voltage regulator may be used to adapt the alternator for use as a 110-120 volt auxiliary power unit. When used for welding, the alternator field is varied over a range of excitation values including values producing overexcitation of the field as compared to ordinary alternator usage. This produces an open circuit output voltage substantially constant and substantially equal to the maximum or peak value of open circuit voltage for which the alternator is designed at a given speed.

Constant-voltage converter having beam current detector

Abstract: A constant voltage converter for use with a cathode ray tube in which a voltage regulator is controlled by both the output of the regulator and beam current from the cathode ray tube by way of beam detecting means The output of the regulator is applied separately to a stabilizing circuit including another feedback circuit for CRT, and also to deflection circuits so as to better prevent fluctuation of picture on the CRT

Voltage, current, or power controller utilizing a switched reactance A.C. shunt regulator

Abstract: Apparatus is described that regulates the transfer of voltage, current, or power from an AC line to a load. The basic controller comprises an inductive element and a switch whose closing converts the inductive element from a series inductance between line and load to a step-down auto-transformer between line and load thus reducing the voltage available to the load and thereby reducing or terminating energy transfer to the load. The switch is connected in series with the inductive element and the combination of the switch and one winding of the auto-transformer is connected in parallel with the load. The controller can therefore be thought of as a switched reactance AC shunt regulator. Theoretically, shunt power in the controller is losslessly returned to the source. The controller is used to regulate any parameter related to the current through the load, the voltage across the load, or the power dissipated by the load simply by controlling the switch with any suitable means for sensing that parameter.

Coherent receiver employing nonlinear coherence detection for carrier tracking

Abstract: The concept of nonlinear coherence employed in carrier tracking to improve telecommunications efficiency is disclosed. A generic tracking loop for a coherent receiver is shown having seven principle feedback signals which may be selectively added and applied to a voltage controlled oscillator to produce a reference signal that is phase coherent with a received carrier. An eighth feedback signal whose nonrandom components are coherent with the phase detected and filtered carrier may also be added to exploit the sideband power of the received signal. A ninth feedback signal whose nonrandom components are also coherent with the quadrature phase detected and filtered carrier could be additionally or alternatively included in the composite feedback signal to the voltage controlled oscillator.

Monolithic integrated voltage stabilizer circuit with tapped diode string

Abstract: This relates to a monolithic integrated voltage stabilizing circuit containing a stabilizing chain of series connected diodes at the connection points of which several stabilized voltages are tapped. All stabilized voltages below the momentary value of the supply voltage are always present. Additional constant current source transistors form a multi-collector lateral pnp transistor.

Highly stable precision voltage source

Abstract: A single polarity voltage source includes a single operational amplifier having its output connected through a serially connected first diode and resistor to the non-inverting input of the amplifier. The juncture of the resistor and amplifier input is connected through a zener diode to ground. The source output voltage of positive polarity is developed across the serially connected resistor and zener diode. This output voltage is highly stable and is used as the supply voltage for the zener diode to thereby provide an extremely stable current supply to the zener diode. A ratio of the resistances of high stability resistors in the inverting input and feedback circuits of the amplifier determines the amplifier gain and thus the magnitude of the output voltage relative to the zener diode voltage. A negative polarity output voltage is developed across the output of a second operational amplifier functioning as an inverter and having its inverting input connected through a potentiometer to the juncture of the serially connected first diode and resistor. The potentiometer is adjusted to match the value of the negative polarity output voltage to the positive polarity output.

Ac voltage sensing apparatus

Abstract: Voltage sensing apparatus for detecting a change in an AC voltage across a line and actuating an alarm when the change occurs. In a preferred embodiment of the invention, the alternating current voltage across the line is converted into a train of square wave pulses, each of which has a pulse width which is a function of the amplitude of the alternating current voltage. A pulse width detector means receives the train of pulses and triggers an alarm means when the pulse width of any one of the pulses in the train varies with respect to a predetermined pulse width. The apparatus is particularly useful in a three-phase system to determine if the voltage across any one of three lines in the three-phase system drops below a reference voltage level.

Voltage-regulated power supply unit

Abstract: Voltage-regulated power supply unit provided with first and second d.c. voltage sources of different voltage levels and first and second regulators. The first regulator delivers a stabilised output voltage. In general, the input voltage of the first regulator is derived from the first source. However, if the output voltage of the first source drops below the working voltage of the first regulator, an additional supply of energy is provided by the second source via the second regulator. A smoothing filter having a certain ripple factor, is inserted in the first source, thus increasing the efficiency of the supply unit.