Showing papers on "Voltage regulator published in 1982"

A simplified maximal power controller for terrestrial photovoltaic panel arrays

Abstract: Perusal of the V-I characteristics of commercial solar panels with insolation, ambient temperature and production spreads as parameter, indicate that the maximum power is obtained from such a panel when it is loaded to a working voltage that is a fixed percentage of its open circuit voltage within (+2)%. This contribution describes a system that uses this characteristic to achieve maximum power control by determining the open circuit voltage and automatically loading the panel to the maximum power point as applied to a battery charging installation. The description includes the application of a novel modified darlington circuit to boost the efficiency of a pulse width controlled switch mode type regulator by reducing the darlington saturation voltage by a compensating voltage. Advanced switching technology is applied to reduce switching losses, and maximise efficiency.

Light dimmer for solid state ballast

Abstract: control system of the current in a high frequency semiconductor ballast powering a gas discharge lamp so as to obtain a dimmer. The ballast comprises an inverter bridge thyristor / capacitor (11) for generating the lamp current which is controlled by a switching circuit (30) synchronized with the zero crossings (31) of the thyristor current. The lamp current and the voltage levels of signals are fed back to the switching circuit for the actual regulation of the lamp current. A variation signal (12) is added either to the lamp current feedback signal is the voltage feedback signal and the composite signal is sent to the lamp power regulator by varying the polarization thereof for selectively controlling light intensity. The light variation can be performed either manually by means of a rotary switch (28) having an output that varies linearly with the rotation of the shaft, or automatically by means of an ambient light level detector (102) to obtain a predetermined output light level which can be adjusted manually. A common insulated gate line facilitates control by photodetection system in a multiple ballast / light, inter-ballast and with the earth insulation being ensured by optoisolators (24, 25). In a preferred embodiment, a balanced bridge being adjustable by the user is sensitive either to manual control inputs or automatic, depending on the light level to vary the polarization of an input amplifier (104) of the regulator lamp current.

Switching regulator power supply

Abstract: The power supply of the present invention regulates the output of a DC voltage source, such as a storage battery, and is adapted to operate in combination with a rectified AC voltage to continue to provide a level DC output voltage in the event AC line power is lost. The switching regulator power supply automatically turns on in response to an AC line outage and provides a DC output voltage regulated by a feedback control arrangement which precisely controls the DC output voltage level. When the rectified AC line voltage is restored, the switching regulator power supply automatically turns off thus reducing DC voltage source usage and prolonging storage battery operating lifetime. The switching regulator power supply of the present invention is particularly adapted for low current applications including providing a well-regulated DC voltage to a volatile memory device of the general complementary-metal-oxide semiconductor type (CMOS) on a standby basis in the event the primary DC source is lost.

Multi-voltage DC output with single reactor voltage control

Abstract: A circuit having voltage regulated DC-output is provided, which may have balanced DC voltages with respect to zero, and which has only a single voltage sensing and power regulating means. The power regulator is on the input of a transformer having at least a bifilar wound secondary and a center tap. One or more pairs of balanced taps, one of each pair on either side of the center tap, are provided; and to each tap there is connected a pair of oppositely facing diodes, connected as to their polarity to provide positive or negative DC voltage with respect to zero; with similarily connected diodes from each pair of diodes at each tap being tied together at their output, facing the output of the circuit. In series with the output terminals of the circuit there are closely coupled, bifilar wound chokes, wound on a single core with isolated windings, and polarity connected to the respective outputs.

Method and apparatus to measure the operating temperature of solid electrolyte-type gas sensors

Abstract: To provide for temperature measurement of a solid electrolyte polarographic gas composition sensor, an ac signal is superimposed from an ac voltage source (2) on the applied voltage from a voltage source (1) if the sensor is a polarographic sensor, the ac signal being separated from the output by a filter combination (6, 7), the dc output being evaluated as usual, and the ac output being rectified in a rectifier (9) to obtain a measure of the temperature since the ac resistance (R alt ) is highly temperature dependent (see FIG. 3). The ac preferably is about 10% of the applied dc voltage, so that the voltage swing of the ac potential falls well within the linear range of output current with respect to voltage (see FIG. 2). The output from the ac channel (7, 9) to evaluate the temperature signal can be connected to a control loop circuit (10, 11), including a heater (11) to heat the sensor to maintain a uniform temperature thereof.

Up-down voltage regulator

Abstract: An up-down voltage regulator includes an up regulator followed by a series pass PNP transistor. The base of the PNP transistor is coupled to an unregulated voltage source. The up regulator is responsive to the voltage at the collector of the PNP transistor to control the emitter voltage of the PNP transistor for all values of the unregulated voltage source to bias the PNP transistor so as to establish and maintain the collector voltage of the PNP transistor at a desired regulated value.

Electronic timepiece with temperature compensation

Abstract: An electronic timepiece having a quartz crystal oscillator circuit as a timebase signal source is provided with a temperature compensation system to compensate timebase signal frequency deviations with temperature, all components of the system being incorporated in the timepiece IC chip. The system is based on a temperature-sensitive voltage stabilizer circuit whose output voltage is current-converted to control the frequency of a temperature-insensitive oscillator circuit. Date generated on the basis of the latter oscillator frequency is applied to compensate the timebase signal frequency, by a capacitor switching technique.

The Effects of Voltage Reduction on Distribution Circuit Loads

Abstract: One method of obtaining energy conservation and peak load reduction is through a reduction in voltage on the utility distribution circuit This paper describes a voltage reduction program which included circuit testing to determine voltage reduction effects, data analysis to isolate the sensitivity of loads to voltage, and circuit analysis to determine categories of loads The actual tactics used to effect the desired reduction in voltage and consumption are also described

High voltage filtering and protection circuit

Abstract: A high voltage filtering and protection circuit that is particularly useful in multilead distribution systems, that include a live, a neutral and a ground line. Transient voltage suppressors are connected from a common node to each of the lines. The suppressors are advantageously silicon diode transient voltage suppressors suitable for high voltage applications, clamping at a rated voltage in one direction and having a forward diode characteristic in the other direction. Each suppressor may be paired with a parallel filter capacitor protected by its diode from surges or transient voltages. The paired suppressors and parallel filter capacitor where polarized capacitors are utilized provides an AC equivalent capacitor. In one arrangement, a gas discharge tube is provided in series with the suppressor that is connected from the common node to the ground line. In another arrangement with or without the gas discharge tube, the suppressors are bidirectional devices with a rated clamping voltage equal to less than the peak line voltage and a predetermined amount greater than one-half of the peak line voltage.

A novel input filter compensation scheme for switching regulators

Abstract: The interaction between the input filter and the control loop of switching regulators often results in detrimental effects, such as loop instability, degradation of transient response and audiosusceptibility, etc. The concept of pole-zero cancellation is employed to mitigate some of these detrimental effects and is implemented using a novel feedforward loop, in addition to existing feeback loops of a buck regulator. Experimental results are presented which show excellent correlation with theory.

Control circuit arrangement for a self-start power supply

Abstract: A switching regulator power supply operates at a variable high frequency with low power dissipation and a minimum of complexity The transformer primary windings are included as part of a self-starting circuit which starts a pulse generator having a fixed frequency and variable pulse width The self-starting circuit includes a control circuit network which connects to the transformer primary windings and a low voltage regulator circuit connects to the pulse generator and network The control circuit network provides the voltage regulator circuit with the desired current characteristics of high instantaneous current during a short turn-on time interval and a zero current during power supply operation The self-starting circuit in response to the input rectified AC power after the short turn-on period of time applies sufficient voltage which enables the pulse generator to begin generating a first output pulse This causes the primary windings to store energy and feedback energy to the self-starting circuit which increases the voltage applied to the generator causing it to begin normal operation at maximum pulse width The output DC supply voltage is compared to a reference voltage for generating an error signal which is used to adjust the width of the pulse generator to existing line and load conditions during power supply operation

A Power System Stabilizer Design Using Digital Control

Abstract: The design of a microprocessor based power system stabilizer operating through excitation control is described. The stabilizer draws all necessary information from sampled values of voltage and current It provides the desired modulating action for damping of machine oscillations by operation of optically isolated switching of taps in an autotransformer interposed in the feedback from potential transformers to the automatic voltage regulator. Included are derivations of algorithms for power and slip used in stabilization control, and demonstration by simulation of the effectiveness of the device.

Voltage regulator for aircraft generators

Abstract: A voltage regulator for aircraft generators controls generator output voltage by controlling exciter field current. Exciter field current sensors and generator output voltage sensors produce control signals which are proportional to exciter field current and generator voltage. These signals are combined and compared with a reference voltage signal by a comparator. A current controller regulates exciter field current in response to the comparator output.

D.C. Stepped-up voltage transformerless battery charger

Abstract: A battery charger that takes energy from a battery and steps-up the voltage to charge another battery. The direct current, going into the charger's circuit goes through the voltage regulator and then to a switching voltage regulator (the integrated circuit) and a few external components which generates the energy to charge the output capacitor. The output capacitor voltage is controlled by a resistive voltage divider network, and energy stored in the output capacitor is transferred through a diode and a current limiter to charge the battery.

Feed forward AC voltage regulator employing step-up, step-down transformer and analog and digital control circuitry

Abstract: A feed forward AC voltage regulator utilizes a step-up, step-down transformer to apply adjustment voltages to an unregulated AC line. Analog circuitry periodically samples the unregulated AC line input and compares it with a scaled representation of the desired line voltage. Digital circuitry converts the information from the analog sampling and comparison to an instruction command which activates an appropriate solid state switch associated with a tap on a multitap transformer connected to the regulated AC output line. The taps are successively located on the multitap transformer to provide selectable adjustment voltages of various values. The switched-in adjustment voltage is provided the proper polarity and applied to the primary of the step-up, step-down transformer, thereby applying to the secondary the adjustment voltage needed to move the regulated AC output line to the desired level.

Voltage dividing circuit

Abstract: Voltage dividing circuits which are comprised of capacitors or resistors. In the case of a voltage dividing circuit comprised of capacitors (Fig. 5), the capacitors (C 1 , Cz) are connected each at one end to an output terminal (V out ) and at the other end connected alternately to two power sources (V 1 , V 2 ) through changeover switches (S 1 , Sz). The switches (S 1 , 8 2 ) are selectively operated so that the capacitors (C 1 , Cz) divide a voltage into fractions of that voltage. The average of the fractions of voltage is taken out as an output voltage (V out ). The averaging of the fractions of voltage cancels out the characteristic difference among the capacitors (Ci, C 2 ). The fractions of voltage are changed by varying the time during which each capacitor (C 1 , C 2 ) is connected to either power source (V 1 , V 2 ). In the case of a voltage dividing circuit comprised of resistors (Fig. 12), the resistors divide a voltage into fractions. The average of the fractions of voltage is taken out as an output voltage (V out ). The voltage dividing circuit may employ a method used in known voltage dividing circuits which comprise capacitors or resistors. In this case, the circuit can divide a voltage into smaller fractions of voltage than the known voltage dividing circuits. In other words, the circuit can enhance the resolution of the analog output signal.

Microprocessor power on reset system

Abstract: Initialization problems in a microprocessor controlled system due to power interrupts or rapid cycling of the ON/OFF control are eliminated by insuring that a logic initialization signal is provided only after microprocessor power up and is removed before the microprocessor is subject to a power outage. By insuring the proper sequencing of the microprocessor initialization input signal and the supply voltage applied thereto, microprocessor operation is initiated under the proper logic and timing conditions. The present invention is particularly adapted for use in a microprocessor controlled tuning system for a television receiver where the power supply is operated not from horizontal scan circuitry but from a conventional 60 Hz power supply. The large time constants used with this low frequency power supply for optimum signal processing generally result in a more rapid decay of the power supply input than the power on reset, or initialization, signal. This may cause microprocessor initialization problems if power is reapplied to the television receiver after a short period. At the start of a power outage, the initialization signal is coupled to and grounded by a shunt regulator to the microprocessor which regulates the 60 Hz power applied thereto.

Digital Simulation of Static Var System Transients

Abstract: This paper describes digital simulation of stAtic AR system transients. Methods are described for simultaneous digital simulation of thyristors, their gate pulse generating circuit, the regulating circuit, and the power system. Results are presented showing a voltage regulator's response to voltage changes and faults.

Resonant current-driven power source

Abstract: A resonant current-driven power source is disclosed. Preferably, the power source is a DC to DC converter regulator including an inductor and capacitor electrically coupled to one another and an input inverter which converts an input DC voltage into an AC voltage having substantially no DC component and applies the AC voltage across the inductor and capacitor in a manner which causes the inductor and capacitor to resonate with one another whereby an AC voltage appears across the capacitor. An output circuit converts the AC voltage appearing across the capacitor into a DC output voltage. A control circuit is provided for controlling the operation of the inverter circuit in a manner which controls the magnitude of the output voltage.

Power amplifier with power supply switching

Abstract: A power amplifier with power supply switching is arranged so that large positive and negative power supply voltages are supplied to collectors of second and fourth transistors via first and third transistors, respectively. Small positive and negative power supply voltages are supplied to collectors of the second and fourth transistors, respectively, and an input signal of the amplifier is amplified by the second and fourth transistors to supply an output of the amplifier to a load, wherein to a base of the first transistor is selectively applied either a divided voltage between a positive constant voltage greater than the small positive power supply voltage and the voltage of the input signal or a voltage which is a sum of the voltage of the input signal and a positive constant voltage. To the base of the third transistor is selectively applied either a divided voltage between a negative constant voltage greater than the small negative power supply voltage and the voltage of the input signal or a voltage which is a sum of the voltage of the input signal and a negative constant voltage. Such selections of application for the bases of the first and third transistors are made in response to a magnitude of the frequency of said input signal.

Method and circuitry for measuring the impedance of a sensor

Abstract: A method of measuring the impedance of a sensor by applying a sine-shaped AC voltage and transforming the response signal proportional to said impedance into a DC voltage such that even for very little measured voltage highest linearity is present. The method comprises the steps of generating a square wave voltage together and in synchronism with said AC voltage, applying said AC voltage to said sensor impedance, filtering the resulting AC voltage and bringing it into a defined phase relation to the square wave and rectifying the AC voltage by means of a switch controlled by said square wave. The rectifier circuit is a low-pass circuit having a grounded resistor which by said switch intermittedly is short-circuited.

The closed-loop stability of power converters with an integrating controller

Abstract: A theory is developed to predict the stability characteristics of static converters as a function of the controlled-firing angle for closed-loop systems using an integrating controller. The controlled quantity can be either the output voltage or current. Revealed in the analysis was how the degree of stability is dependent on the operating point, the waveform and pulse number of the supply, the commutating reactance, and the method of modulating the firing angle. The factors that determine stability are related to the step change in the output voltage waveform at the instant of switching. In practical application of the theory, the closed-loop performance can be improved by suitably shaping the modulating function or `firing wave'. It is found that the optimum shape of the firing wave is not the same shape that produces a linear open-loop voltage gain.

Constant voltage DC arc welding apparatus

Abstract: A DC arc welding apparatus compares the output voltage with an adjustable, preset voltage, and the amplified and integrated difference signal is supplied to a current control circuit together with a current feedback signal. The resulting apparatus operates in a constant voltage mode, thus rendering it applicable to consumable electrode welding. A constant current mode may also be realized, as an alterantive, by bypassing the comparator and feeding the preset voltage directly to the current control circuit.

Avalanche photo-diode bias circuit

Abstract: An avalanche photo-diode bias circuit compensates for temperature variations in the breakdown voltage by controlling the bias voltage so that the ratio of the bias voltage to the breakdown voltage remains constant, to achieve a constant current amplification factor.

Vehicle mounted voltage regulator

Abstract: In a roadway vehicle having a storage battery and an engine-driven alternator, the battery voltage is controlled by a voltage regulator which has a first voltage detector for detecting when the battery voltage reduces below a higher reference level at which the battery voltage is normally controlled, and a second voltage detector for detecting when the battery voltage reduces below a lower reference level. A third voltage detector detects when the alternator voltage rises above a predetermined level. A logic gate circuit responds to outputs from the second and third voltage detectors by generating a warning signal. A semiconductor switching element is coupled in series with the field coil of the alternator to supply thereto the alternator voltage in response to a switching control which is generated in response to an output signal from the first voltage detector to cause the switching element to operate the alternator in a high output state and in response to the logic gate circuit to operate the alternator in a low output state.

Field effect transistor microwave amplifier

Abstract: In a microwave preamplifier of a Doppler radar system used for Earth observation, three pre-matched and self-biassed field effect microwave transistors are provided. By supplying these transistors by means of a voltage regulator, whose output voltage varies under the action of a control circuit, the gain of this pre-amplifier may be varied without modifying the standing wave ratio, thereby obtaining modulation of the microwave signal amplified by the amplifier. Thus, additional modulation may be obtained, speech modulation for example, on the transmission signal of an Earth observation Doppler radar system.

Temperature limited voltage regulator circuit

Abstract: Field coil current of an alternator is controlled in response to temperature as well as to battery voltage, thus allowing maximum safe output power at any ambient temperature. A monostable circuit is utilized for reducing the maximum duty cycle of the field excitation driver in response to a sensed temperature without increasing power dissipation in the regulator.

Charge transfer constant volt-second regulator

Abstract: A voltage regulator circuit is disclosed which utilizes the stored charge on the intrinsic gate capacitance of a field effect transistor as the means to switch the power in a switch mode voltage regulator in conjunction with a constant volt-second regulator, where the stored charge is derived from the timing capacitor.

Control apparatus for charging generator

Abstract: A control apparatus for a charging generator for charging a battery comprises a first temperature detecting element having a positive temperature coefficient which detects the variation of ambient temperature of a voltage regulator to impart a negative temperature gradient to the voltage adjusting characteristic of the voltage regulator and a second temperature detecting element having a negative temperature coefficient which detects the self-heating of the generator or the voltage regulator during operation to impart a positive temperature gradient to the voltage adjusting characteristic so as to control the output voltage of the generator. This control apparatus has a dynamic characteristic permitting the adjusted voltage to increase so as to compensate the voltage drop in the external load characteristic; thus an excellent charging characteristic of the battery can be attained.

Control circuit for light emitting diode

Abstract: A circuit for controlling one or more light emitting diodes is disclosed. The circuit is designed to supply current to the diodes from an input voltage source in response to a control signal. The circuit provides a predetermined level of current to the diodes which is substantially independent of the magnitude of the input voltage. The circuit also includes a switching function which operates to switch off the diode current when the control signal exceeds a first level of control voltage. When the control signal is reduced below a second level of control voltage, the diode current is switched to the predetermined level of current.