Showing papers on "Voltage regulator published in 1979"

Modelling and analysis of switching DC-to-DC converters in constant-frequency current-programmed mode

Abstract: An analysis of dc-to-dc switching converters in constant-frequency current-programmed continous conduction mode is performed, and leads to two significant resuslts. The first is that a ramp function, used to eliminate a potential instability, can be chosen uniquely to assure both stability and the fastest possible transient response of the programmed current. The second is the development of an extension of the state-space averaging technique by means of which both the input and output small-signal properties of any such converter may be accurately represented by a linear small-signal equivalent-circuit model. The model is presented and experimentally verified for the cuk converter and for the conventional buck, boost, and buck-boost converters. All models exhibit basically a one-pole control-to-output transfer fuction response.

Controllable d.c. power supply from wind-driven self-excited induction machines

Abstract: A variable-speed generating system is described which uses a 3-phase squirrel-cage induction machine with self-excitation capacitors. The variable-frequency/variable-voltage generated is then fed through a 3-phase controlled rectifier to provide a d.c. supply at constant voltage. The proposed scheme is suitable for wind power sources as it allows wide changes in wind turbine speed and, at all speeds, optimum generating power can be set up by rectifier delay angle control.

Solid-state regulated voltage supply

Abstract: A solid-state (IC) regulated voltage supply compensated for effects of changes in temperature comprising first and second transistors operated at different current densities. Associated circuitry develops a voltage proportional to the Delta VBE of the two transistors and having a positive temperature coefficient. This voltage is connected in series with the VBE voltage of one of the two transistors, having a negative temperature coefficient, to produce a resultant voltage with nearly zero temperature coefficient. A feedback circuit responsive to current flow through the two transistors automatically adjusts the base voltages to maintain a predetermined ratio of current density for the two transistors. Other embodiments provide higher-level DC outputs and compensation for base current flow.

Detecting circuit for a power source voltage

Abstract: A detecting circuit for a power source voltage comprises a reference voltage generating circuit for generating a reference voltage, a voltage dividing circuit for dividing the power source voltage, and a voltage comparing circuit having one input terminal connected to receive the reference voltage from the reference voltage generating circuit and another input terminal connected to receive the divided voltage from the voltage dividing circuit. In one embodiment, the reference voltage generating circuit comprises at least two MOS-transistors having different threshold voltages and having the same polarity, one of the MOS-transistors having its gate and drain connected together with the drain being connected to the gate of the other MOS-transistor, the drain and source of the other MOS-transistor each being connected to a resistor, and the drain of the other MOS-transistor being connected to one input terminal of the voltage comparing circuit. In another embodiment, the reference voltage generating circuit comprises a P-channel MOS-transistor having its drain connected to the drain of the N-channel MOS-transistor and the gates of the P-channel and N-channel MOS-transistors being connected to the drains thereof respectively, one of the MOS-transistors being connected to one terminal of the power source, and the other of the MOS-transistors being connected to one input terminal of the voltage comparing circuit.

Buck/boost regulator

Abstract: A voltage regulated DC to DC converter is disclosed which is operable over a wide range of input voltage including voltages greater or less than the desired output voltage The converter uses an inductor and a capacitor as storage elements, the inductor being composed of two windings having a common junction A transformer having a center tap connected to the common junction of the two windings of the inductor is connected at either end of its winding to ground through controlled switches One winding of the inductor and either end of the transformer winding are connected by respective power diodes to the capacitor which supplies the output voltage to a load The other winding of the inductor is connected to a fourth power diode as a clamping diode Input voltage is supplied to the inductor through a third controlled switch A pulse width modulator connected to the output of the converter alternately closes and opens the switches connected to either end of the transformer winding and also closes the switch supplying input voltage to the inductor each time either of the switches connected to the ends of the transformer winding are closed The duty cycle of the closing and opening of the several switches is adjusted by the pulse modulator to regulate the output voltage

Air-fuel ratio detecting system

Abstract: An air-fuel ratio detecting system is designed to compensate for the effects of temperature changes on the output resistance of an air-fuel ratio sensor adapted to detect the air-fuel ratio of mixture supplied to an engine from the composition of its exhaust gases so as to vary its electric resistance in accordance with the air-fuel ratio The system further includes a current control circuit for controlling the current supplied to the air-fuel ratio sensor, an average voltage detecting circuit for detecting a rich air-fuel ratio peak voltage and a lean air-fuel ratio peak voltage and obtaining the intermediate voltage therebetween, a bias control circuit responsive to the value of the intermediate voltage so as to adjust the current control amount of the current control circuit, and a comparator responsive to the junction point voltage and the value of the intermediate voltage so as to generate an air-fuel ratio detection signal Alternatively, the average value of the rich side peak voltage and the ground voltage or the average value of the lean side peak voltage and the supply voltage may be used as the desired intermediate voltage

A voltage control apparatus for electric generators for vehicles

Abstract: A voltage control apparatus for an electric generator (2-4) for vehicles includes an armature winding (3), an exciting coil (4), a rectifier (2) for rectifying an a.c. output from the armature winding (3), and a voltage regulator (5). The voltage regulator (5) comprises a differential amplifier circuit (26) producing a detected voltage corresponding to a difference between a battery charging voltage and a reference voltage, a comparator circuit (30) comparing the detected voltage with a triangular waveform voltage generated at constant periods and producing a pulsed output voltage, a first driver circuit (51) effecting duty-factor-control of an exciting current flowing through the exciting coil (4) in response to the pulsed output voltage, and an initial excitation circuit (32) for causing a predetermined small initial exciting current to flow through the exciting coil (4) intermittently during a time interval after the start of the electric generator (2-4).

Optimum Design of RC Snubbers for Switching Regulators

Abstract: The optimum design of an RC snubber to suppress the surge voltage across the transistor in a switching regulator with a two-winding reactor is presented. Analyzing the surge voltage by means of high-frequency equivalent circuits, we obtain the third-order characteristic equation. This third-order equation is first analyzed by the aid of the root locus method. As a result, the region where the surge voltage can be suppressed is described in the R-C plane. Then considering the snubber loss, the optimum resistance and capacitance can be obtained. Second, the precise design procedure of RC snubbers is discussed by normalization and numerical calculations. This procedure is summarized in easy-to-use nomographs.

Battery charger and power supply circuitry

Abstract: A transformerless battery charging circuit is described including a rectifier (10'), a semiconductor switch (12'), in series with the battery (14), a sensing network (16') monitoring battery voltage, a trigger circuit (18') responsive to the sensed battery voltage for controlling operation of the semiconductor switch (12'), and a voltage regulator (20') for regulating output voltage of the rectifier (10') as supplied to the triggering and battery voltage sensing networks The circuitry in combination with an appropriate rechargeable battery (14) also serves as a power supply to drive a DC load connected to the battery (14)

Drive circuit for an infrared remote control transmitter

Abstract: An infrared remote control transmitter includes at least one infrared light-emitting diode poled with respect to a point of reference potential so as to be conductive in response to voltages having the opposite polarity of a DC supply voltage and to be nonconductive in response to voltages having the same polarity as the DC supply voltage. A push-pull amplifier is responsive to a pulse signal encoded to represent a remote control message to selectively couple the DC supply voltage or the reference potential to a capacitor coupled in series between the push-pull amplifier and the light-emitting diode. The capacitor is charged and discharged and an alternating drive voltage for the light-emitting diode having portions with polarities both the same as and opposite to the polarity of the DC supply voltage is generated. The push-pull amplifier is arranged so that when a component failure occurs, the portions of the alternating drive voltage having the polarity opposite to the polarity of the DC supply voltage are at least inhibited to prevent the continuous (i.e., DC) emission of infrared radiation.

CMOS Voltage regulator circuit

Abstract: A CMOS integrated circuit chip includes a conventional high voltage section and a low voltage section. An on-chip voltage regulator develops a second or pseudo substrate potential at a node that is regulated to a level that is the sum of the thresholds for NMOS and PMOS devices below the VDD potential. The low voltage section is connected between VDD and the second substrate potential node. The low voltage section is, therefore, always operated at optimum voltage regardless of device threshold voltage variations that are encountered in CMOS manufacturing. This means that even though the integrated circuit includes a low voltage section, it can be operated over the normal CMOS voltage range as if it contained only high voltage devices.

Rectifier assembly for AC generators for use with vehicles

Abstract: There is disclosed a rectifier assembly for an AC generator for use with vehicles. The rectifier assembly comprises a single horseshoe heat radiating plate and electric circuit elements mounted thereon, and including at least one rectifier unit and two DC output conductor plates. The two d.c. output conductor plates are disposed in spaced relationship on one surface of the heat radiating plate with an intermediate insulating layer and electrically connected to output terminals of the rectifier unit. The assembly may be incorporated with a voltage regulator of an integrated circuit configuration for controlling the output voltage of the AC generator and a brush holder. The voltage regulator may be coplanar with the conductor plates.

Pulse switching for high energy lasers

Abstract: A saturable inductor switch for compressing the width and sharpening the rise time of high voltage pulses from a relatively slow rise time, high voltage generator to an electric discharge gas laser (EDGL). The switch also provides a capability for efficient energy transfer from a high impedance primary source to an intermediate low impedance laser discharge network. More specifically, a saturable inductor switch is positioned with respect to a capacitive storage device, such as a coaxial cable, so that when a charge build-up in the storage device reaches a predetermined level, saturation of the switch inductor releases or switches energy stored in the capacitive storage device to the EDGL. Also disclosed are cascaded saturable inductor switches for providing output pulses having rise times of less than ten nanoseconds as required for efficient excitation of EDGL's, the pulse rise time being determined by the thickness of a high permeability material forming the saturable inductor switch. In addition, a technique for magnetically biasing the saturable inductor switch is disclosed so that only pulses from a pulse generator having one polarity are passed and pulses having the other polarity are blocked, thereby improving the lifetime of electrical components that are sensitive to voltage reversals.

Switching regulator provided with charge-discharge circuit having overcurrent protecting function and soft-start function

Abstract: A switching regulator in which an input DC voltage is chopped and then applied to drive a transformer from which an AC voltage is derived which in turn is rectified in a rectifier circuit, and the output of the rectifier circuit is compared with a first reference voltage so that an output is provided which corresponds to the difference between the two voltages compared with each other and which causes a current to be charged at a capacitor incorporated in a charge-discharge circuit which is arranged to vary the charged current, and the output of the charge-discharge circuit is compared with a second reference voltage so that a trigger signal is produced and applied to the base of a switching transistor only when the output of the charge-discharge circuit exceeds the second reference voltage.

Voltage regulator with temperature dependent output

Abstract: A solid state voltage regulator circuit having an output with absolute voltage change per degree centigrade temperature dependence comprises a voltage regulator having a forward control loop for sensing changes in regulated output voltage, and a temperature transducer having an output voltage connected to the forward loop and adapted to change the sensed regulated voltage input to the regulator in direct proportion to the absolute ambient temperature. The transducer output is connected to the forward loop by an amplifier and the circuit is readily adapted to any desired linear temperature dependence by adjustment of the gain of the amplifier.

Voltage regulator circuit with multiple control functions

Abstract: A voltage regulator circuit provides multiple control functions in respect to an automotive alternator including limiting of the field current to within a predetermined level. The regulator circuit includes a current control device for controlling the alternator field current, and a plurality of comparator networks to one of which is applied a field current reference signal and a sensing signal and to others of which are applied various alternator voltage reference signals and voltage sensing signals. The outputs of said comparator networks are employed in an OR fashion to control the field current control device.

Average current controlled switching regulator utilizing digital control techniques

Abstract: A current controlled switching type voltage regulator achieves voltage regulation by controlling an average current flow through the switching device. This current is sensed and transformed into a signal frequency. The signal frequency is counted to determine its average value and this count is compared to a variable current reference count which is continuously adjusted in response to an output voltage monitor which includes circuitry to generate an error count responsive to the deviation of the voltage output from a desired regulated value. In order to counteract instability problems inherent in current controlled switching type voltage regulators the transducer converting current into a signal frequency has a threshold characteristic to insure a definite fixed signal frequency at very low currents.

Standing wave ratio detecting apparatus

Abstract: A standing wave ratio detecting apparatus is disclosed which comprises an integration circuit for integrating a traveling wave detection voltage V F , a comparator circuit for comparing the output voltage V' F of the integration circuit with a reflected wave detection voltage V R to a voltage E o proportional to the voltage ratio V R /V' F , a control circuit receiving the output voltage E o of the comparator circuit and turned on or off according as the output voltage E o is put in a high level or in a low level to lower or raise the output voltage V' F of the integration circuit, thereby conducting such a control as making the output voltage V' F approximately equal to said reflected wave detection voltage V R and maintaining the amplitude of the output voltage E o constant, a smoothing circuit for deriving an average voltage corresponding to the ratio V R /V F of the reflected wave detection voltage V R to the traveling wave detection voltage V F from the output voltage E o of the comparator circuit, and a meter for indicating the average voltage from the smoothing circuit

Substrate bias regulator

Abstract: A substrate bias regulator useful for controlling a variable output oscillator and/or a substrate bias voltage generator is provided to control the substrate voltage on a semiconductor chip. A series of field effect transistors are arranged in a manner to sense the substrate voltage and to provide an output to regulate the substrate voltage. One of the series field effect transistors has its gate electrode connected to reference potential ground which tends to make the regulator independent of transistor thresholds.

Fire detection system with multiple output signals

Abstract: A fire detection system includes a single conductor pair for both supplying the energizing voltage to all of the fire detectors in the protected area and receiving back status information regarding the individual detector operation. The system provides individual, successive alarm outputs to regulate successive functions such as "evacuate the area", "dump the fire extinguishing material", and "call in the local fire department", as successive ones of the detectors are alarmed. The system includes a voltage regulator for supplying a well regulated voltage to the detectors, which regulator is switched into a current limiting mode to prevent an inaccurate first alarm signal if the conductor pair is short circuited. This system also provides a trouble-indicating output signal if the system loses supply voltage or experiences a ripple voltage beyond a preset amplitude.

Integrated rise-time regulated voltage generator systems

Abstract: Integrated circuit system for generating a rise-time regulated and level controlled high voltage pulse utilizing a plurality of diode-connected stages driven by capacitively coupled low voltage clocks. The maximum output voltage may be controlled by a gated diode reference device, which provides a reference voltage independent of power supply voltage. A feedback circuit may be provided which controls the high voltage rise time by modulating the effective low voltage clock amplitude driving the high voltage generator. A MOS logic level interface circuit may also be provided for sensing achievement of the predetermined high voltage level.

Stabilized switching voltage regulator comprising means for preventing overloads due to initial surge currents

Abstract: A switching voltage regulator (86) is controlled to produce a low output voltage when the power is first turned on and subsequently to produce a high output voltage after a predetermined length of time has elapsed, thereby eliminating overloads due to initial surge currents.

Comparison of multiρle-output DC-DC converters using cross regulation

Abstract: A new multiple-output dc-dc converter is analyzed, in which the cross regulation is performed by the energy-storage reactor as well as the transformer. The steady state and the dynamic characteristics of this converter is compared both theoretically and experimentally with those of the conventional one composed of the step-up-down type circuit. As the results of comparative analysis, it is revealed that this new converter is superior to the conventional one in the steady state and the dynamic performances. Further, it is demonstrated experimentally that the cross regulation performance of this new multiple-output converter is less affected by the leakage flux in the energy-storage reactor, and also that this converter is very useful as a preregulator for the continuous series regulator in cases requiring a high degree of regulation of the multiple-output voltages.

Voltage regulator for variant light intensity photovoltaic recharging of secondary batteries

Abstract: A simplified voltage regulator circuit permits varient light intensity photovoltaic recharging of secondary batteries. The regulator circuit electronically shunts serially connected regions of a photovoltaic recharger array to avoid overcharging during periods of high light intensity or full battery charge conditions. The regulator circuitry provides minimal series resistance to the photovoltaic array and requires nominal driving power. The photovoltaic array and the regulator circuitry may comprise discrete components or may share a common substrate body.

Method and apparatus for generating an air gap flux signal for an AC machine from AC line voltage and current values

Abstract: A substantially smooth, continuous and sinusoidal air gap flux signal for an AC machine is provided from machine terminal voltages and line currents. A voltage representative of the machine stator voltage is combined with a voltage representative of the resistive voltage drop component across the stator to yield an intermediate voltage. This intermediate voltage is integrated and combined with a voltage representative of the stator flux leakage reactance to yield an air gap flux signal proportional to the difference between the integral of the intermediate voltage and the stator flux leakage reactance voltage.

Series pass voltage regulator with overcurrent protection

Abstract: A series pass voltage regulator compares the output voltage with a reference voltage and adjusts the base bias of a PNP series pass transistor coupled between an unregulated voltage source and a load to maintain the output voltage at a predetermined constant value. A current sensing resistor senses the base current of the PNP series pass transistor and limits the base current to a predetermined value indicative of a maximum allowable load current.

A.C. Motor control circuit

Abstract: A tachometer is coupled to the rotor of an A.C. motor and generates an output voltage proportional to the rotor's speed. A VELOCITY COMMAND voltage is generated having an amplitude which specifies a desired rotor speed. The tachometer voltage is subtracted from the VELOCITY COMMAND voltage to produce a VELOCITY ERROR voltage. The output of a D.C. power source is chopped at a fixed frequency and variable pulse width, the pulse width being proportional at any time to the amplitude of the VELOCITY ERROR voltage. The chopped D.C. voltage is filtered to provide a variable D.C. voltage having an amplitude which is proportional to the amplitude of the VELOCITY ERROR voltage. The variable D.C. voltage is applied to an inverter which changes it into an A.C. voltage. The A.C. voltage is applied to the stator windings of the motor to drive the rotor thereof. The frequency of the A.C. voltage is variable and is proportional, at rotor speeds above 150 RPM, to the amplitude of the velocity command voltage. At rotor speeds below 150 RPM, the frequency of the A.C. voltage is held fixed at approximately 28 Hz. The amplitude of the A.C. voltage is proportional to the VELOCITY ERROR voltage at all speeds. The frequency of the A.C. voltage is determined by an oscillator which drives a ring counter whose counting direction is controlled by a direction flip-flop. The state of the direction flip-flop is changed whenever the polarity of the VELOCITY ERROR voltage changes so that deceleration of the motor always occurs in a plugging mode.

Automatic circuit tester with improved voltage regulator

Abstract: A battery operated microcomputer controlled programmable circuit testing device. Standard I/O/memory devices (25a, 25b) are connected to a microcomputer (20) in such a manner as to treat the I/O ports (46, 47) of the I/O memory devices as programmable interfaces and to allow pin receptors in a socket (10) to be individually programmed as inputs or outputs. Double detent switches (12, 13) connected to testable inputs T0, T1, 45) the microcomputer are used to scroll a roll table containing names of devices which may be tested in either a forward or a reverse direction at two different speeds. Compression of the roll table storage is provided by storing only data which differs from the previous element. A power supply (17) having a regulator featuring a series pass transistor (150) connected as a common collector amplifier is shown. The power supply is turned on and off by switching devices (11, 151, 160, 159) which control base current only to a transistor switch (155, 170) operating analog circuitry (157) which controls the pass transistor. Microcomputer control (181) of the power supply and self latching embodiments are also shown. The power supply shown herein can successfully regulate output voltages which differ from the raw DC input by no more than the saturation voltages of series pass transistor.