Abstract: A power semiconductor device (10) and a method for increasing the turn-on time of the power semiconductor device (10). The power semiconductor device (10) has a first stage (13) and a second stage (14), where the transconductance of the first stage (13) is less than the transconductance of the second stage (14). The turn-on time of the power semiconductor device (10) is increased by turning on the first stage (13) before turning on the second stage (14).

Abstract: A switching power supply unit controls an output voltage of a power supply without monitoring an output voltage. The switching power supply unit includes a pulse width modulator for generating a control signal to turn on and off a switching transistor. A central processing unit outputs a modulation signal to control the pulse width modulator while sensors detect an input voltage, an output current and a peripheral temperature. A table is used by the central processing unit to store information about a relation between the detected values from the sensors and an ON time of the switching transistor. The central processing unit then selects an ON time of the switching transistor from the table according to values detected by the respective sensors to thereby provide control for switching the switching transistor on and off.

Abstract: A charging apparatus having a power supply circuit that provides a DC output current via a sense resistor. A current detector amplifies, detects and provides a voltage across the sense resistor. A controller designates the output of the current detector as a determination signal when the DC output current is equal to a preset voltage. Responsive to the determination signal, the controller generates a control signal in order to control the DC output current of the power supply circuit. More particularly, the current detector includes a first differential amplifier that amplifies and output the voltage across the sense resistor, a second differential amplifier amplifies and supplies a differential voltage between the output of the first differential amplifier and a predetermined first reference voltage, and a first output circuit responsive to the output of the second differential amplifier delivers the determination signal.

Abstract: This invention provides a facsimile apparatus which can reduce the consumption power of main power supply control means, and can suppress the charging frequency of a secondary battery without widening the operating voltage range of the main power supply control means.The facsimile apparatus has a main power supply control unit. The main power supply control unit has a DC--DC converter which receives a power from a secondary battery, a solar battery, or a main power supply, and operates to maintain a constant output voltage, and a microcomputer driven by the output voltage from the DC--DC converter. The output voltage from the DC--DC converter is detected by a voltage detect circuit, and a voltage from the secondary battery is detected by another voltage detect circuit. The microcomputer performs control for supplying a power from the secondary battery or the solar battery to the DC--DC converter, control for charging the secondary battery by the main power supply or the solar battery, and the like.

Abstract: An electric power supply apparatus comprises a traveling-wave tube 15 exhibiting partial negative-resistance characteristics and a voltage stabilizing circuit for controlling a voltage control element 12 using an error amplifier 16 and a switch and for supplying stable power to the traveling-wave tube 15. In the apparatus, whether a traveling-wave tube 15 is in positive-resistance operation or negative-resistance operation is detected. In the negative-resistance operation, the control using the error amplifier 16 and the switch S1 is rendered ineffective.

Abstract: This invention discloses an active electrical current filter including an N-channel FET controller coupled in series along a positive electrical line between an electrical power input and an electrical power output having voltages within a given range, apparatus for providing a driving voltage to the FET controller, the driving voltage being in excess of the voltages within said given range, and a differential voltage sensor, which senses the difference between the voltages at the filter input and output and whose output governs the driving voltage supplied to the FET controller, the active electrical filter exhibiting a voltage drop of less than one volt.

Abstract: In a regulated power supply circuit, a "J characteristic curve" is obtained between an output current and an output voltage. Moreover, the output current is minimized in a grounded state in which the output terminal is grounded to minimize heat dissipation so as to facilitate circuit integration. Between the input and output terminals, there are connected an output-stage transistor and a current sense resistor in series. A voltage sense circuit senses voltage between an output terminal of the transistor and a ground terminal. The current sense circuit senses the output current by the current sense resistor. The transistor has a base terminal connected to output terminals of the voltage and current sense circuits, respectively. In this configuration, when the output terminal is grounded, the output current is set independently of a current value sensed at occurrence of an excess current. This consequently lowers the power consumption of the regulated voltage circuit in the grounded state.

Abstract: Main power supply circuit includes an inrush current suppressing circuit serially connected between its rectifying circuit and a load, this inrush current suppressing circuit being composed of a current limiting resistor and an FET switch that is serially connected to this resistor. An auxiliary power supply circuit provides power for a control circuit of the main power supply circuit, and, after the power supply switch is closed, a delay circuit monitors rise of a charge voltage of a smoothing capacitor within the main power supply circuit as well as rise of control circuit voltage of the auxiliary power supply circuit and establishes a delay time. After the elapse of the delay time, the FET switch is turned ON and the inrush current suppressing circuit is closed. The inrush current suppressing circuit is then short circuited within a short time period and the load operation is continued.

Abstract: A solar array maximum power point tracking system for regulating the power output of a solar array associated with a spacecraft. An on-board computer measures the bus voltage and current from the solar array and generates a power calculation of the solar array power output. The on-board computer applies a first reference signal to a remote error amplifier representative of an incremental change in the solar array power. Additionally, the solar array bus voltage is applied to the remote error amplifier such that the remote error amplifier senses the solar array bus voltage and generates an output voltage indicative of the change of the solar array power. The output voltage of the error amplifier is applied to a power processor unit. The output voltage from the remote error amplifier and the bus voltage are applied to a power stage within the power processor unit. The power stage generates an output current that is applied to an arcjet thruster.

Abstract: A voltage regulator controller including means for creating multiple regulator setpoint configurations. Configurations can be selected upon demand, by time/date activation, or by an external trigger source.

Abstract: A voltage regulator in the form of a series regulator for generating a regulated supply voltage includes a control loop with a reference network, a difference device, and a control element. The control element is connected between a first terminal and a second terminal. The power supply for the reference network and the difference device is coupled to the second terminal. During a starting phase, a starting device with an auxiliary circuit pulls the control loop into the regular operating range.

Abstract: Adaptive control of converters is provided to achieve, in one case, a constant current characteristic by controlling input power as a function of the ratio of output voltage to output current. In another class of circuits, input current to the converter is controlled under an adaptive control arrangement in response to output voltage/output current ratios which may also be modified by input current or input voltage. The adaptive control may be augmented with low frequency negative feedback control loops.

Abstract: A DC-DC converter is provided which is operable to drive a reactive circuit (10) that includes both a series inductor (12) and a capacitor (14) disposed between the output node and ground. The DC-DC converter includes two switches, a transistor switch (20) connected between a positive supply and an input node (16) and a second transistor (28) connected between the node (16) and ground. In one mode of operation, the transistors (20) and (28) operate in an asynchronous regulation mode with clock signals provided to the gates thereof. In a second asynchronous mode of operation, transistor (28) is turned off and replaced by its junction isolation diode (48). The transistor (20) is driven by a clock signal in accordance with an asynchronous regulation mode of operation. In a third mode of operation, the modified asynchronous duty cycle to the gate of transistor (20) is altered.

Abstract: A portable electronic system, which can accurately predict impending battery failure, without using expensive comparators, by using voltage and current measurements to determine the source impedance of a battery. Preferably two banks of batteries are used, with a load-switching relay; the voltage and current of both banks is monitored, so that voltage drop under load can be monitored. Alternatively, the voltage variation of a single battery bank can simply be correlated to the current drawn by a changing load.

Abstract: The synchronous switching power supply can be employed in multiple output power supply systems requiring extremely high efficiency and low number of components. The input signal may be AC or pulsating DC. A single switch is switched at zero voltage and current. The short circuit protection is inherent. A switching power supply with boost or flyback converter includes an inductor coupled to a node for attaining a current, a switch coupled to the node for selectively applying the input signal of one polarity across the inductor, wherein the inductor and switch are separately coupled to the input and ground in either order, a capacitor providing the output signal, rectifier coupled between the node and capacitor for conducting the current, a pair of comparators for comparing the input and output signals against respective reference signals, a circuit for determining an optimum value of the current as to minimize an overshoot of the output signal, and a circuit controlling the switch.

Abstract: A linear voltage regulator for regulating the voltage and current in a DC supply is described. The invention includes current and voltage sense elements. The outputs from the sensed elements are summed together as the gate input to an FET pass transistor which regulates the power supplied. The two feedback loops provide high bandwidth and improve dynamic response.

Abstract: A direct current power source circuit has a voltage control power MOS-FET and a back gate control circuit. The voltage control power MOS-FET is connected between an input terminal and an output terminal of the circuit and the back gate control circuit is connected to a back gate of the voltage control power MOS-FET and controls a back gate voltage for causing a parasitic diode between a source and a drain of the power MOS-FET to become a non-conductive state when an input voltage applied to the input terminal becomes a low level. The output of the back gate control circuit is also connected to a voltage dividing circuit which sets an output voltage of the power source circuit. The arrangement enables to prevent a reverse flow of current from the output terminal to the input terminal.

Abstract: The synchronous switching power supply can be employed in multiple output power supply systems requiring extremely high efficiency and low number of components. The input signal may be AC or pulsating DC. A single switch is switched at zero voltage and current. The short circuit protection is inherent. A switching power supply with buck converter includes a switch for selectively applying the input signal of one polarity to a node, an inductor coupled to the node for attaining a current, a rectifier coupled between the node and ground for conducting the current, a capacitor coupled between the inductor and ground for providing the output signal, a first comparator for comparing the input signal against a first signal, a second comparator for comparing the output signal against a second signal, and a control circuit responsive to the first and second comparators for controlling the switch.

Abstract: A circuit having a load connected to ground, a measuring resistor connected in series with the load; a current source feeding current into the load and the resistor, a different amplifier having one output connected to one end of the resistor and having its output connected to a summing point which is an input from the current source, a reference voltage source having one end connected to the summing point, is improved by an impedance converter having its input circuit connected to another end of the resistor and its output connected to another input for the differential amplifier, the latter output being further connected to an opposite end of the reference voltage source thus serving as floating ground for the reference source and the differential amplifier.

Abstract: A technique for operating a common emitter circuit from a plurality of supply voltages. In one embodiment, a current mirror includes a plurality of diode-connected transistors each connected between a source of current and associated supply voltages. Corresponding current mirrors are each connected between an output terminal associated supply voltage leads, thereby providing an output current mirrored from the soure of current, regardless of which of the supply voltages are activated, and regardless of their particular levels. In another embodiment, a regulator includes an output transistor having a plurality of current handling terminals, each connected to an associated supply voltage, and a second current handling terminal coupled to an output terminal.

Abstract: A constant power circuit for causing a constant power level to be dissipated by a load when an overpower condition is detected. The overpower condition is detected by measuring the voltage across and current drawn by the load in accordance with a programmed load value and determining whether the sum of the measured current and voltage exceeds the power limit for the load. In a preferred embodiment, the sum of the voltage and current is compared to a linear piecewise approximation of a constant power curve in the current-voltage plane, the curve representing the power limit for the load for the range of current and voltage magnitudes in which the load circuit may safely operate. When an overpower condition is detected, the power is dissipated by the load at a constant power level defined by the constant power limit by oscillating the power level within a hysteresis band about the constant power limit.

Abstract: There is provided a source voltage control circuit including a reference voltage generating circuit with a negative feedback circuit, a source voltage level sensing circuit for increasing the internal source voltage when the external voltage exceeds a given voltage, a first differential amplifying circuit for active operation, and a second differential amplifying circuit for stand-by operation, whereby a stable internal source voltage is produced and the slope of the internal source voltage is readily adjusted when the external source voltage exceeds the given value. The first differential amplifying circuit receives the reference voltage and the internal source voltage, controlled by a first control signal and the output of the source voltage level sensing circuit. The second differential amplifying circuit receives the reference voltage and the internal source voltage, controlled by a second control signal.

Abstract: An automotive voltage regulator is disclosed to have plural regulated outputs using a transient protected isolator output stage (TPIOS) that prevents a system fault condition on any one output from adversely affecting the other outputs. In an automotive environment employing a nominal 14-volt supply, an individual output can be taken from -4 to +26 volts without causing damage or having any significant reaction on the non-faulted outputs. The circuit employs a relatively small NPN output pass transistor and, therefore, requires a relatively low value stabilizing bypass capacitor.

Abstract: Disclosed is a device power supply in a semiconductor test system for supplying programmed test pattern voltages to a semiconductor device under test and for current range switching of current range resistors without effecting the output voltage of the device power supply.

Abstract: A voltage stabilizer with a very low voltage drop includes a series voltage regulator circuit having a first PNP transistor connected to an input terminal of the stabilizer via a second PNP transistor and being connected to ground via a capacitor. The stabilizer has biasing and switching circuits disposed between the input terminal thereof, a base terminal of the second transistor and ground.

Abstract: A power supply control circuit which enables the constant current and constant voltage feedback loops to be compensated independent of each other. In accordance with the invention, an inner feedback loop has been added which is local to the output stage so as to allow a constant voltage feedback loop to see a closed loop transfer function of the inner feedback loop that mimics an output for a constant voltage preferred output stage even though a constant current preferred output stage is used. As a result, load impedance variations that would have affected the loop gain of the constant voltage feedback loop affect the loop gain of the inner feedback loop only. The inner feedback loop is disposed such that it is automatically disabled by the constant current feedback loop when the power supply enters the constant current mode and hence allows the constant current and constant voltage modes to be decoupled from one another.

Abstract: In an AC to DC power conversion circuit including a boost inductor connected in series between a full-wave rectifier and a DC load, a switch is connected to selectively shunt boost inductor current from the load. Switch conduction is controlled by a pulse width modulator generating switching pulses at a high fixed frequency. The pulse widths are automatically varied as a function of boost inductor current, load voltage, and an ideal sinusoidal waveform derived from the AC input voltage to force the boost inductor current to closely conform to the ideal sinusoidal waveform and thus minimize harmonic distortion, while achieving load voltage regulation and near unity power factor.

Abstract: A series pass voltage regulator is provided which has reduced power dissipation in the semiconductor components of its output stage. The output stage includes first and second impedances which are electrically connected in parallel for collectively carrying a load current supplied at an output of the regulator. The first impedance comprises the series combination of a transistor collector-emitter output impedance and a resistor, while the second impedance comprises the series combination of a transistor collector-emitter output impedance and two diodes. The bases of the two transistors are coupled to the output of an error amplifier to effect control of the output impedances. In all high load current situations, the resistor dissipates more than 75% of the power dissipated in the output stage.

Abstract: A constant voltage source circuit which is provided with an output transistor (Q.sub.1) for outputting a predetermined output voltage (V.sub.0) in accordance with an input voltage (V.sub.IN) and a differential amplifier (A), and is further characterized in that the circuit further comprises a reference voltage control means which monitors variations of the input voltage (V.sub.IN) and outputs a predetermined constant voltage to the differential amplifier (A) as a reference voltage when the input voltage (V.sub.IN) is higher than, a predetermined voltage level, and a voltage varied in accordance with the variation of the input voltage (V.sub.IN) is output therefrom to the differential amplifier (A) as a reference voltage when the input voltage (V.sub.IN) falls below a predetermined voltage level.

Abstract: Monitoring an electric power distribution circuit having a rated load capacity includes continually sensing an intensity of electric power supplied through that circuit. In response to that sensing a first signal indicating when electric power is supplied through that circuit at a predetermined maximum current usage below rated load capacity is provided. A second signal indicating a safe loading condition is provided when the sensed intensity is substantially below that maximum current usage. A third signal is provided when the mentioned intensity is at a value between the safe loading condition and the maximum current usage.

Abstract: A power supply has the source and drain of a MOSFET arranged for connection etween an input voltage source and a load. In normal operation a bias voltage is applied to the gate to place the MOSFET in a conductive state. A difference amplifier maintains a fixed ratio between a reference voltage and the output voltage. Current limiting circuitry senses the current that the power supply provides to the load and disables the MOSFET when the current provided to the load exceeds a predetermined value. Thermal shutdown circuitry senses the operating temperature of the power supply and places the MOSFET in a nonconductive state when the operating temperature exceeds a predetermined value.

Abstract: A method and arrangement for suppressing noise having an alternating voltage component in a load supplied with a direct voltage signal by way of a control loop including a final controller connected to the load. The final controller is connected to the load by way of only an ohmic resistor. The signal at the output of the final controller contains an alternating voltage component of the noise. A signal proportional to the alternating voltage component of the noise in the load is formed in a branch circuit separate from the control loop supplying the load. The proportional signal is fed in phase opposition to the signal appearing at the output of the final controller ahead of the ohmic resistor with an amplitude corresponding to the amplitude of the alternating voltage component of the noise dropped across the ohmic resistor.

Abstract: A regulated power supply employs two separate sources of power which are serially connected by a variable impedance element, such as a transistor, connected between the two power sources. Output voltage of the power supply is equal to the sum of the individual power supply voltages minus a voltage drop across the variable impedance element. A sensor circuit employing standby and active mode branches is coupled between output terminals of the power supply for control of the variable impedance element. The active branch of the sensor is switchably connected to an output power terminal of the supply so as to be operative only during the active mode. The standby branch comprises a resistive network coupled to a reference diode while the active branch comprises a feedback amplifier coupled to the reference diode.

Abstract: The disclosed driving circuit is composed of a driving transistor connectable to a load in accordance with an input signal, a first control device operating in case of driving the load having a relatively large resistance for producing a first control signal effective to control the driving transistor to drive the load by a constant-voltage type operation, a second control device operating in case of driving the load having a relatively small resistance for producing a second control signal effective to control the driving transistor to drive the load by a constant-current type operation, and a selecting device selectively applying either of the first and second control signals to the driving transistor according to the value of the load resistance connected to the driving transistor.

Abstract: A voltage source with preset values of the source voltage and the internal resistance is simulated by a computing circuit (25, 26; 35, 36; 47) which calculates a reference parameter (S.sub.UO ; S.sub.IO) for a current or voltage regulator (20; 30; 40) that forms the output of the voltage source. The reference parameter (S.sub.UO ; S.sub.IO) corresponds to the output current (I.sub.O) or the output voltage (U.sub.O) and is obtained from a measured parameter (M.sub.UO ; M.sub.IO) and the input parameters (S.sub.U ; S.sub.R) which correspond to the values to be set. The measured parameter (M.sub.UO ; M.sub.IO) is derived from the output voltage (U.sub.O) or the output current (I.sub.O). When using this simulation circuit, separate high load resistors and mechanical switching contacts are unnecessary and the input parameters (S.sub.U ; S.sub.R) can be set with analog switches.

Abstract: An input-output interface disposed between an electrical device and a switching device which has opened and closed states and is controlled by a voltage of a voltage regulator and comprising a resistor disposed between the output of the switching device and the input of the electrical device, a first voltage holding circuit for holding the voltage at the input of the electrical device to a first voltage which corresponds to a high input voltage of the electrical device, a second voltage holding circuit for holding the voltage at the input of the electrical device to second a voltage which corresponds to a low input voltage of the electrical device, a first current control circuit controlling a current flowing into a line between the resistor and the input of the electrical device, causing a first current to flow when the voltage at the input of the electrical device is less than a third voltage which is between the high input voltage and the low input voltage of the electrical device, and causing a second cur

Abstract: A D.C. power supply in which the output capacitor used in the CV mode of operation is removed from the output circuit in the CC mode of operation and charged to the voltage between the output terminals so as to prevent transients or switch stressing that could be caused when the output capacitor is reconnected to the output circuit for CV operation. In a preferred embodiment, first and second FET's are connected in series between the input and output terminals of the supply. While the first is used for control during CV operation, the second is in saturation, and while the second is used for control during CC operation, the first is in saturation. The output impedance of the supply is decresed during CV operation by connecting the source electrode of the first FET to the output electrode, and the output impedance of the supply is increased during CC operation by connecting the drain electrode of the second FET to the output electrode.

Abstract: A following voltage/current regulator includes a field effect transistor (FET) (48) connected in series between an unregulated voltage source (44) and a load, such as a motor bridge circuit (50). The conduction of the FET is controlled by a control circuit (56) which measures the input voltage to the FET source, the output voltage from the FET drain and the current drawn by the load. Initially, when power is turned on, the inrush current to the load is limited until a predetermined voltage differential between the input and output voltages is achieved at steady state. Then, the voltage regulator maintains the predetermined voltage differential to provide a well regulated output voltage to the load despite fluctuations in supply voltage. This "following" action limits the heat disipation and protects the FET. Because the voltage regulator uses no inductors or transformers, there are no saturation problems and the circuit may be compactly packaged.

Abstract: A voltage stabilizer with a minimal voltage drop designed to withstand high voltage transients includes a "series" type voltage regulator circuit with an NPN power transistor. The collector terminal of this transistor is connected to ground via a capacitor and to the cathode of a diode whose anode forms an input terminal of the stabilizer. The base terminal of the power transistor is connected to the collector terminals of first and second PNP transistors which have their emitter terminals respectively connected to the cathode and anode of the diode and their base terminals connected to a circuit biasing circuit.

Abstract: A low dropout voltage regulator with a switched redundant input, which has low dropout voltage before, during, and after a switch to the redundant input. In a preferred embodiment, the inventive voltage regulator includes two transistors that are controlled by the output of an error amplifier, and redundant input voltage sources. A first one of the transistors conducts when a first input voltage is greater than a second input voltage. The other transistor conducts when the second input voltage exceeds the first input voltage. When both input voltages are have substantially equal magnitude, both transistors conduct. In a preferred embodiment, one input voltage is supplied by a battery, and the other is supplied by a storage capacitor charged by the battery. When the battery fails, the storage capacitor will discharge, thus serving as a time-varying redundant voltage source in the event of battery failure.

Abstract: A voltage regulator powered by an electrical power source having a discharging voltage characteristic and regulating the voltage applied to an electrical load from the power source includes a stable reference voltage source, a sensor for sensing the voltage applied to the load, an error signal generator for generating an error signal related to the difference between the sensed and reference voltages, and a voltage control connected in series with the electrical load and responding to the error signal to control the voltage applied to the load as the power source discharges. The invention is particularly useful when the power source is a single cell battery and the load is a direct current motor. Embodiments of the invention may apply a substantially constant or an increasing voltage to a load as the source voltage declines according to its discharge characteristic.

Abstract: A series voltage regulator having a regulating transistor (T.sub.1) arranged with its emitter-to-collector path in a series arm of the regulator, the base of which is controlled via a control transistor (T.sub.2) by a first differential amplifier (V) which compares a reference voltage (U.sub.REF) with a voltage proportional to the voltage (U.sub.2) of the regulator output. A differential circuit (V.sub.2) which compares the collector-to-emitter voltage of the regulating transistor (T.sub.1) with an auxiliary voltage (U.sub.3) is provided, the output of which is followed by a current limiting circuit (T.sub.3) which acts upon control transistor (T.sub.2). The auxiliary voltage (U.sub.3) is larger than the collector-to-emitter voltage of the regulating transistor (T.sub.1) which occurs at the beginning of the saturation state of the regulating transistor. The current limiting circuit (T.sub.3) limits the current delivered by the control transistor (T.sub.2) to the base of the regulating transistor (T.sub.

Abstract: A direct current power supply configuration for use in a wide variety of electronics applications, is described. The invention features high precision capability with relatively simple circuitry. A system of panel indicators eliminates the need for a panel voltmeter and improves serviceability and ease of operation over the prior art.

Abstract: A ripple reducing circuit wherein ripple voltages across the output terminals of a voltage source are coupled through a ripple sensing circuit to an amplifier. The sensed ripple is amplified and phase reversed to provide signals in phase opposition to the ripple signals. These phase opposition signals are coupled via an anti-ripple element to the output terminals of the voltage source for effecting ripple level reduction.

Abstract: A series voltage regulator having a regulating transistor (T.sub.1) arranged with its emitter-to-collector path in a series arm of the regulator, the base of which is controlled via a control transistor (T.sub.2) by a first differential amplifier (V) which compares a reference voltage (U.sub.REF) with a voltage proportional to the voltage (U.sub.2) of the regulator output. A differential circuit (V.sub.2) which compares the collector-to-emitter voltage of the regulating transistor (T.sub.1) with an auxiliary voltage (U.sub.3) is provided, the output of which is followed by a current limiting circuit (T.sub.3) which acts upon control transistor (T.sub.2). The auxiliary voltage (U.sub.3) is larger than the collector-to-emitter voltage of the regulating transistor (T.sub.1) which occurs at the beginning of the saturation state of the regulating transistor. The current limiting circuit (T.sub.3) limits the current delivered by the control transistor (T.sub.2) to the base of the regulating transistor (T.sub.

Abstract: A power supply circuit for use with telecommunication subscriber lines provides a substantially constant power output over one range of load impedances and a substantially constant voltage output over a range of load impedances greater than a critical impedance. The circuit employs a transformer which includes a sense winding for sensing output voltage across the load. For load impedances below the critical value, the current into the primary of the transformer is controlled by means of a current sensing device sensing the amount of primary current. However, for load impedances greater than the critical impedance the output of the sense winding controls and current to the primary is reduced to avoid the output voltage from rising substantially even in the event of an open circuit load condition. In one embodiment, a supervisory circuit provides a signal indicative of the on-hook and off-hook states of the subscriber line by sensing primary current flow.

Abstract: A voltage regulator for an alternator has an integrated actuator stage consisting of a Darlington transistor pair and includes an auxiliary stage which, at the time of starting of the alternator, causes a low voltage drop across the actuator stage by causing only one of the two transistors in the Darlington transistor pair to conduct. This provides, at the exciter winding of the alternator, disposed in series with the actuator stage, the current required for the starting of the alternator at a low rotational speed.

Abstract: An alternating current voltage regulator is provided which clips the maxima of the positive and negative portions of the incoming alternating current wave form at a regulated level thereby producing alternating current output wave form, and which varies the regulated output voltage level in response to changes in output current. The preferred regulator includes two electrically independent regulating sections, one for clipping the positive portion of the alternating current wave form and the other for clipping the negative portion of the incoming alternating current wave form. Preferably each independent regulating section includes means for sensing the positive and negative portions of the output current respectively and for varying the regulated level of the positive and negative output voltages respectively in response thereto. A second embodiment is illustrated using the amplifier as part of the current sensing means for use with high load current applications.

Abstract: A highly stable voltage regulator circuit based on a low-voltage reference and supplying a voltage which is substantially higher than the reference voltage. The circuit is to be constructed as an integrated circuit comprising transistors of one conductivity type and without a zener diode.The reference voltage is supplied by a "band-gap reference" circuit (1). A differential circuit (T16, T17) controls the output voltage, which is applied to the base of a transistor (T16) via a resistor (R16) in which the current is maintained constant by means of an associated differential circuit (T11, T12) which comprises a resistor (R11) connected between its emitters. The bases of the transistors T11, T12 are each connected to one end of a resistor (R20) arranged in a bridge connected between the reference terminal and ground.

Abstract: The invention is directed to a circuit arrangement for controlling the current through an electric load such as an electromagnetic load. A current-controlling element controls the current through the load in response to a control unit. The voltage at the load is compared with a voltage which depends on the control unit which drives the current-controlling element. The current through the electric load is then controlled in dependence upon the result of this comparison. An embodiment is described by means of which the entire circuit arrangement is protected against function failures or even destruction.