Showing papers on "Voltage regulator published in 1970"

New developments in IC voltage regulators

Abstract: A temperature-compensated voltage reference that provides numerous advantages over zener diodes is described along with the implementation of thermal overload protection for monolithic circuits. The application of these and other advanced design techniques to IC voltage regulators is covered, and an example of a practical design is given.

A Method of Resonant Current Pulse Modulation for Power Converters

Abstract: A nonlinear, active network that transforms the voltage waveform of a unipolar source of energy is presented. This network consists of ideally lossless elements such as inductors, capacitors, and on-off switches. Control is obtained by variation of the mode of switch operation. A circuit philosophy is applied which is adapted to the characteristics of switch operation and confines the stresses imposed on circuit components to moderate levels. Results of experimental work are reported and include: 1) test data of a 95 percent efficient, 2-kW dc transformer having a power density of 0.4 kW/kg; and 2) integration of this transformer with a 20-cm ion propulsion engine for spacecraft.

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.

Piezoelectric vehicle impact sensor

Abstract: A piezoelectric vehicle impact sensor which is responsive to changes in the vehicle''s velocity caused by particular impacts upon the vehicle from predetermined directions relative to the vehicle. A piezoelectric crystal which has a sensitive axis is firmly attached within the vehicle. A mass is mounted within the vehicle for compressing the crystal along the sensitive axis in response to an impact from the predetermined directions, thereby causing the crystal to generate a voltage as a function of the impact. A voltage limiter limits the amplitude of the voltage to a predetermined level. An integrating circuit receives the voltage from the voltage limiter and produces a signal which is an integral of that voltage. A detecting circuit is responsive to a particular value of the signal from the integrating circuit for activating an apparatus such as an inflatable passenger restraining system.

The derivation and application of design equations for ferroresonant voltage regulators and regulated rectifiers

Abstract: Design equations for the most commonly used ferroresonant 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. Frem these expressions, 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.

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.

Two conductor telemetering system

Abstract: In a two conductor telemetering system, a sensor and transmitter are disposed at an outlying station. The transmitter produces a train of pulses having a repetition rate which is a function of the quantity being measured by the sensor. The pulses are transmitted over a two conductor transmission line to a base station counter to the flow of power from the base station to energize the sensor and transmitter. A switching voltage regulator is provided at the outlying station for converting the supplied dc power of a relatively high unregulated voltage and low current to a regulated relatively low voltage at high current for energizing the sensor and transmitter.

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.

Overcurrent and overvoltage protection circuit for a voltage regulator

Abstract: A combined overload and overvoltage protective circuit for solid state devices which utilizes two transistors in a NOR logic gate configuration that is held normally off by a common emitter bias supplied through a feedback current developed from voltage supplied to a load. Either transistor is switched on to shunt supply current away from solid state devices of the circuit during an overload or input overvoltage condition. In case of overload, excessive load current causes the development of an increased drop across the base-emitter circuit of one transistor countering the hold off bias developed from the feedback current. An input overvoltage causes a Zener diode to conduct and to develop an increased drop across base-emitter of other transistor countering the same hold off bias developed from the feedback current.

Intrinsically safe electrical barrier system and improvements therein

Abstract: A multiple barrier system for limiting transfer of electrical energy to intrinsically safe levels, including n individual barriers each having a fuse and two resistors in series and a zener diode for limiting the voltage at the junction of the resistors. A high-voltage selector also connects each such voltage to a master barrier having a voltage limiting zener diode. The master barrier''s zener diode is bypassed by a controlled rectifier which fires if the last said diode is over driven. In a modification, the one resistor of an individual barrier is replaced by a current limiting impedance consisting of self-biased transistors.

Power supply system and control circuits therefor

Abstract: There is disclosed a regulated power supply system wherein an alternating current supply voltage is converted to a direct current voltage, which is regulated and applied to a converter, the converter including a pair of switching transistors for switching current through a linear transformer core and a further pair of switching transistors connected as a push-pull saturable reactor oscillator or inverter for supplying switching potentials to the first pair of transistors. A zener reference diode is used to sense over-voltage conditions to a load and automatically adjust a switching transistor in the regulator to adjust the voltage to the load. In accordance with the invention, one or more switching devices are connected across the zener diode, one of which is operated in accordance with signals from a computer or other low level signal source so as to turn on and turn off the power supply and the other of which is connected to a current sensing resistor for shunting the reference zener diode on current overloads. A further feature of the invention is in the overall system of conversion wherein power for the saturable reactor inverter and other operating potentials for the regulating circuit are derived from the regulator circuit per se, thereby improving the efficiency of the system.

Stability of synchronous machine with divided-winding rotor

Abstract: To deal with a divided-winding rotor (d.w.r.) synchronous machine in which the two field windings are not located on the rotor axes and may not have equal numbers of turns, an equivalent machine is introduced with field windings on the direct and quadrature axes. The steady-state stability calculations are carried out by applying the Nyquist criterion to the linearised equations for small oscillations of a system with more than one feedback regulator. This investigation is followed by using the nonlinear differential equations and a digital computer to find the transient response after a change in the tieline impedance. The calculated results are confirmed by experiments carried out on the micromachine equipment at Imperial College, London. The alternatives studied included systems using one regulator at a time, both regulators together and various transfer functions for each regulator. The main conclusion is that the angle regulator stabilises the voltage regulator and has a major influence on the stability of the system; hence the voltage-regulator gain can be varied over a wide range.

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.

Generator voltage regulator with detachable resistance unit in the voltage reference circuit

Abstract: A voltage regulator adjustment device including a plurality of series-connected resistors contained in a body having two sets of terminals for removable connection with other structures. One set of terminals is adapted for connection with a conductor contained in a cap so as to short any of the resistors in the body. The other set of terminals is removably connected across terminals of an otherwise inaccessible voltage regulator located in the housing of an alternator, thereby inserting the resistors of the body into a voltage divider contained in the regulator. A reference point in the voltage divider is operatively connected to an output transistor in the regulator to control the output of the alternator in accordance with the voltage at the reference point. Therefore, by adding the resistors of the body and shorting those desired with the conductor in the cap, the voltage setting of the voltage regulator is in effect altered to provide a different output voltage for the alternator.

Threshold voltage determination system

Abstract: In a character recognition system, a threshold voltage determination system for providing a decision making voltage level separating "black" data signals from "white" data signals. A plurality of scanning amplifiers are individually coupled in an electrical parallel circuit to a voltage divider which responds to variations in the "black" data signals. The threshold voltage determination system generates a voltage level which is intermediate the voltage magnitude of the "black" data signal and the "white" data signal. A minimum threshold voltage level is also provided to maintain a predetermined minimum decision making voltage level in the absence of character being read.

Power feed regulator system for temperature regulation and the like

Abstract: A power feed regulator system for temperature regulation and the like includes an input analog circuit which provides a control signal related both to ambient temperature and to a preset control point. The control signal is amplified and applied both to the inverting input of a first power feed regulator and to the noninverting input of a second power feed regulator. Depending on whether the signal is positive or negative, only one or the other power feed regulator is operated and actuates a triggering circuit which starts up a servo motor provided for turning on or off an appliance such as a hot water supply valve. Each power feed regulator has a hysteresis comparator comprising an operational amplifier, a resistor and a capacitor in series between the output of the amplifier and the ground with a feedback loop applying to the inverting input of the power feed regulator a part of the voltage between the terminals of the capacitor. The power feed regulator delivers an output periodic square-wave voltage having lower and higher values independent of its input voltage and an average power substantially proportional to the input voltage.

Regulator with optical feedback arrangement wherein both input and output voltage are sensed

Abstract: An alternating current phase control regulator circuit for controlling the energization of a load from an alternating current supply. A feedback arrangement is provided which senses in each half-cycle of the supply voltage, both the output voltage of the regulator, as supplied to the load, and the input voltage of the regulator, as supplied by alternating current supply, to provide feedback signal indicative of both the input and output voltages. The regulator which is energized by the alternating current supply includes a ramp and pedestal amplifier which amplifies the feedback signal to provide a firing signal to a bilateral semiconductor switch which phase controls the energization of the load.

Voltage regulator indicating circuit for undervoltage, normal voltage and overvoltage conditions

Abstract: An indicating circuit for use in a vehicular electrical system having a DC power source and a dynamoelectric machine to supply a charging current to the DC power source. One or more indicating lamps are provided to give visual indication of the various operating conditions of the dynamoelectric machine to indicate failure of an alternator or regulator components or to indicate below normal, normal, and above normal voltage outputs therefrom. Where two or more indicating lamps are used, they are controlled by voltage differential amplifiers having gated outputs therefrom connected to a third amplifier. The third amplifier control energization of the indicating lamp which indicates the normal voltage output of the dynamoelectric machine, and energization of either of the two voltage differential amplifier circuits will render the third amplifier inoperative by a signal through the associated gate circuit.

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.

Switching voltage and current regulator controller

Abstract: A switching voltage and current regulator controller having an isolation transformer coupling a supply voltage to a load with an isolation amplifier in a feedback loop to deliver error information from the secondary back to the primary while maintaining the required primary-secondary isolation, the error information being proportional to the pulse width in the pulse train transferred through the coupling transformer.

Time ratio solid state voltage regulator

Abstract: The solid state switches connected to fixed taps on a voltageinjecting transformer winding in a solid state step voltage regulator or load tap changing transformer are controlled synchronously to effectively insert the winding in series with the line for a variable number of half cycles, or preferably full cycles, of a base time interval. In addition to zero and full value voltage insertions, a variable portion of the full value voltage increment is injected in series with the line voltage without increasing the number of switches.

Damping of Power Oscillations in Salient-Pole Machines with Static Exciters

Abstract: It is generally accepted that a high-performance excitation system may reduce the effective internal damping of a synchronous machine. Alternately, studies and field tests indicate that a fast-acting excitation system offers the best opportunity for increased damping through the use of an auxiliary signal into the voltage regulator. The application of static exciters to water-wheel generators requires an awareness of these possible changes in machine damping. The use of an auxiliary damping signal into the voltage regulator may become especially important for machines that are inherently lightly damped.

High frequency parametric voltage regulator

Abstract: A parametric regulator in which an inverter is positioned between the input source of power and a parametric device to provide the parametric device with a high frequency input. The output of the parametric device is rectified and monitored by a sensing circuit which controls the frequency of the inverter to maintain the output voltage constant. A sensing and control circuit is provided which permits the use of conventional transistors in the inverter by establishing a proper timing pattern for the triggering of these transistors into and out of conduction.

Inductor surge protection for transistors

Abstract: A circuit for clamping a voltage induced across an inductor utilizes a Zener diode to control the energy dissipation of the inductor through a transistor. A driver circuit for an inductor includes a Zener diode and an opposing diode connected across the series combination of the base-emitter junction of an emitter-follower output transistor and the inductor driven thereby. When the transistor is conducting, the inductor is energized and no current flows through the Zener diode. When the transistor is caused to cease conduction, the field of the coil of the electromagnet collapses, generating a voltage that is applied to the emitter of the output transistor. If the voltage thus generated is greater than the Zener breakdown voltage, the Zener diode breaks down and provides a bias current to the base of the output transistor to permit further conduction of the transistor and clamps the voltage at the emitter of the transistor to substantially the value of the Zener breakdown voltage. The voltage generated by the inductor is thus prevented from applying too high a voltage across the collector-emitter circuit of the output transistor, which might damage the transistor. The transistor continues to conduct during the dissipation of the energy stored in the inductor until the inductor is almost fully deenergized and can no longer generate a voltage equal to the Zener diode breakdown voltage. The output transistor is then rendered nonconductive, completing the deenergization of the inductor.

Regulator apparatus responsive to generator output power factor and voltage

Abstract: Regulator apparatus for a synchronous machine having a field winding, and terminals connected to an electrical system. The regulator apparatus utilizes the power factor at the terminals of the synchronous machine to control the excitation of the field winding during normal circuit conditions, and the voltage at the terminals to control the excitation during system voltage disturbances.

Temperature compensated bias circuit

Abstract: Disclosed is a monolithic voltage regulator having a high current capability, a constant low output impedance from DC to several hundred kilocycles, and a high ripple reduction factor. The regulator has excellent transient response; it provides a wide range of regulated output voltage and has a low temperature drift. The voltage regulator includes a voltage standard or bias source, an input differential amplifier stage having a pair of transistors coupled to a current sink (a current source passing current to ground), and one of the transistors in the pair is connected through a current gain stage to an output terminal. A DC reference shifting circuit is connected to the input of one transistor in the pair and provides a reference voltage to the differential amplifier stage which has been translated to provide the required voltage level at the output terminal. The output terminal is connected directly to the input of the other transistor in the pair in order to achieve a unity feed back factor to provide excellent constant loop performance independent of the output voltage. The direct coupled feedback connection eliminates any undesirable gain loss and phase shifting due to resistance in the input circuits of the differentially coupled transistor pair.

Voltage regulator for brushless alternator

Abstract: A voltage regulator for brushless alternators including an oscillator circuit which has the output thereof fed into a stationary, primary winding of a rotary transformer device which, in turn, has a secondary winding thereof rotatable with the rotor shaft of the alternator. The oscillator is a free running oscillator at substantially a fixed frequency and the output of the alternator is fed back to a voltage sensor circuit which, in turn controls the oscillator between fully on and fully off conditions to regulate the output therefrom to the primary winding of the rotary transformer thereby regulating the power output of the alternator.

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.