Abstract: Method and apparatus for controlling a turn-off power converter valve having at least two series connections. Each non-latching power semiconductor switch of this power converter valve has an active collector-emitter limiting circuit. When a rising edge of a drive signal that is provided arrives, a predetermined value of the reference limited voltage of the active collector-emitter limiting circuit is decreased to a low value and is increased to the predetermined value again during a turn-off operation. Using a switch-on command, it is possible to balance the voltage sharing on the non-latching power semiconductor switches of a turn-off power converter valve having at least two series connections.

Abstract: A bi-directional power converter apparatus and method of conversion is disclosed which comprises three active elements (output, primary, and auxiliary switches) and two passive components (primary and auxiliary energy storage elements) coupled so as to enable operation in any one of several different power conversion modes, including: a Non-Assisted Generation mode, a Super-Assisted Generation mode, a Super-Assisted Regeneration mode, an Auxiliary Generation mode, and an Output Regeneration mode. The individual components operate in a synergistic fashion to enable the free, bi-directional, transfer of power from primary and auxiliary energy sources to a load, and from the load to the primary and auxiliary energy sources. Further, the invention operates in such a way as to dramatically reduce the effective boost/buck ratios required for low voltage energy sources connected to a high voltage output power bus.

Abstract: A load drive control apparatus includes a drive control circuit for driving and controlling a load in response to a given drive condition. A power supply circuit operates for feeding drive electric power to the drive control circuit. The feed of the drive electric power to the drive control circuit by the power supply circuit is controlled in response to a control signal for drive and control of the load to implement a change between a normal mode of operation and a stand-by mode of operation in which consumed electric power is reduced.

Abstract: A power transistor switched power supply connecting a power source to a capacitive load, including a circuit and method for limiting the inrush surge current through the power transistor. The control gate of a junction field effect transistor (JFET) is coupled between the conductive path of the power transistor and the load to sense voltage drop across the power transistor. The conductive controlled path of the JFET is connected to control the impedance of the power transistor. The JFET shunts some of the power transistor control terminal current during the on transition allowing the power transistor to only turn partially on for a period of time, thus limiting the current through the power transistor from the power source to the load. Because the inrush surge current is limited, the accompanying transient power source voltage drop is reduced with less impact to other circuits connected to the power source.

Abstract: Programmable voltage regulators that change from a first set-point voltage to a second set-point voltage at a controlled rate. The set-point signal is a multi-bit set-point signal with the rate of change in the regulator output between set-points being predetermined or externally controllable. Various embodiments are disclosed.

Abstract: An apparatus for establishing an operating parameter for a power supply device having an output includes: (a) a first signal source; (b) a second signal source; (c) a third signal source; and (d) a state device. The first signal source is controllable for generating a programming signal. The second signal source generates a load indicating signal and is connected with the power supply. The third signal source generates an offset signal. The state device has a first input and a second input and changes state when the first input has a predetermined relationship with the second input. The first input is determined by relative values of the programming signal and the offset signal. The second input is related with the output. The power supply device shuts down when the state device changes state.

Abstract: Circuitry for driving an electrical load (18) and regulating a load current (IL) therethrough includes a multiple output load driving device (20) having an input (26) receiving a gate drive signal (GD) thereat and operable to direct the load current (IL) therethrough from a collector (28) to main (22) and sense (24) outputs thereof. A control circuit is provided including an error amplifier (52) having a non-inverting input operable to receive a reference voltage and an inverting input operable to receive a sense voltage proportional to the portion of load current (IL) flowing through the sense output (24) of the load driving device (20), and producing an output based thereon to which a gate drive control circuit (54) is responsive to supply the gate drive signal (GD). A feedback capacitor (CFB) is disposed between the collector (28) of the load driving device (20) and a resistor string (R8, R9, RTRIM) establishing the reference voltage, and provides an AC coupling therebetween.

Abstract: A board mountable power supply module is described. The power supply module includes a power train for converting an input voltage into a regulated output voltage and a controller operable to control the power train. The power train is connected to the input and output voltages through an input voltage pin, an output voltage pin and a common pin. The controller includes a multifunction control pin, which allows for disabling the power supply module and for trimming the output voltage. Additionally, two or more power supply modules can be connected in parallel to form a power supply that is capable of meeting increased load current requirements. Each of the multifunction control pins in the power supply is electrically connected together to improve current sharing between modules by reducing internal variances between modules.

Abstract: An electronic, proximity-type switching device with a first switching device terminal (1), a second switching device terminal (2), a sensor and evaluation circuit (3) which contains an externally influenceable proximity indicator and an operating voltage supply circuit for making available the internally required operating voltage (= internal operating voltage) and with an electronic switch (4) which is controllable by the sensor and evaluation circuit (3), for example, a switching transistor, the sensor and evaluation circuit (3), on the one hand, and the electronic switch (4), on the other, being connected essentially in parallel and to the first switching device terminal (1) and the second switching device terminal (2).

Abstract: A power control apparatus is provided that receives an input power voltage from a power source and supplies a corresponding output power voltage to a device. The apparatus contains a counter, a processor, and a switch. The counter inputs a power control signal and outputs a count signal that corresponds to a lapsed time from when the power control signal is input. The processor inputs the count signal and outputs a time out signal. The time out signal has a first value if the lapsed time and a predetermined time have a certain relationship, and the time out signal has a second value if the lapsed time and predetermined time do not have the certain relationship. The switch receives the input power voltage from the power source and the time out signal. If the time out signal has the second value, the switch does not output the output power voltage to the device.

Abstract: A converter for reducing the amplitude of a DC input signal includes first and second switches that each are coupled between an input port for receiving the input signal, and voltage reducing circuitry for reducing the amplitude of the input signal. The two switches are configured so that at least one of the switches is open at all times, thus reducing the heat generated by either one of the switches. This consequently reduces the need for heat dissipation devices such as, for example, conventional heat sinks. Moreover, the two switches each may be smaller than that which would be used if a single switch were used since their duty cycles are much smaller than that of such single switch. The converter further includes an output port coupled to the voltage reducing circuitry for providing an output signal having an amplitude that is less than that of the input signal.

Abstract: A digital programmable DC—DC voltage-down converter which can be used in a low voltage and low power digital circuit design is disclosed. The DC—DC voltage-down converter includes at least a digitally controlled oscillator (DCO), a pulse-width modulator (PWM), a gate driver, and a switching-type voltage-down converter. Duty cycle and operating frequency of the modulated signal are controlled by using two digital control signals. Furthermore, combining the pulse-width modulator and the digitally controlled oscillator (DCO), the duty cycle of the generated clock is more robustly stable for different frequencies during process variation.

Abstract: The present invention relates to a circuit for simulating a break-over semiconductor component, including at least one switch simulating a switching function of the component and at least one voltage or current sensor controlling the switch, the sensor being associated with an adjustable check value corresponding to a characteristic value of the break-over component to be simulated by the circuit.

Abstract: A dual mode converter is provided that may be operated as a variable-frequency, naturally-commutated controller in a Zero-Voltage-Switching mode and as a fixed-off-time controller in a Fixed-Off-Time mode. The converter includes four functional elements. A reference and biases element generates voltage references and biases utilized to determine various signal states. A Timing element generates a fixed off time signal and a voltage ramp signal utilized to create the dual modes of operation. A Catastrophic-Event element detects events that cause the converter output be inhibited and the controller to be restarted. A Mode Detection and Pulse Width Modulation element determines the mode of operation for the converter based on signal inputs from the other functional elements and modulates the output accordingly. In a primary mode, the controller utilizes variable frequency operation to deliver primary power. In a standby mode, the controller utilizes fixed frequency operation to provide low power (less than 5W).

Abstract: A switching mode voltage regulator circuit that operates at reduced quiescent current levels is provided. The voltage regulator preferably includes a control circuit and a switching element that connects and disconnects filter circuitry from the control circuit. An error amplifier in the control circuit is placed in a micropower operating state when the regulator is in standby mode to reduce quiescent current.

Abstract: Dashboard dimmer light circuit for a vehicle, for example a car or truck. A power supply 10 provides a step-function voltage signal to an op-amp oscillator circuit 20 which provides a triangular voltage oscillation signal to an op-amp level comparator 40 which, in turn, compares the triangular voltage oscillation signal to a voltage reference for providing a pulse-width-modulated (PWM) voltage signal to a power FET driver 70 which, in turn, responds to the pulse-width-modulated voltage signal by providing a current signal to an automobile dashboard dimmer light 80. Features of the invention include a) a dashboard dimmer light having a stable oscillator frequency, b) PWM duty cycle stability in a dashboard dimmer light, c) efficient accomplishment of the invention's oscillator and level comparator functions within a single IC, d) reduction of electromagnetic interference which might otherwise intefere with other electronic equipment in the dashboard.

Abstract: A switching regulator of which efficiency is increased while the switching regulator is operated under low load condition is disclosed. The switching regulator is arranged by: a reference voltage circuit for producing a reference voltage; an error amplifier for entering thereinto the reference voltage and a measuring voltage produced by subdividing an output voltage from the switching regulator and for amplifying a difference voltage between the reference voltage and the measuring voltage; an oscillator circuit for outputting an oscillator signal; a PWM comparator for comparing an output voltage of the error amplifier with an output voltage of the oscillator circuit; load detecting means for detecting an output load current; and efficiency varying means for varying an efficiency of the switching regulator in response to load conditions detected by the load detecting means.

Abstract: A control system for a switching regulator which linearizes the relationship between the control input signal and the duty ratio of the pulse output. A logarithmic signal generator furnishes a logarithmically increasing signal to a comparator circuit. The comparator circuit compares the logarithmic signal to a control input signal and triggers a pulse generator such that the frequency of the pulses has an exponential relationship to the control input signal. The pulses are averaged and the average is subtracted from a reference signal. The result is then used as the input to the logarithmic signal generator. The resulting relationship between the duty ratio of the pulse output and the control input signal is linear.

Abstract: A portable power system for a hand tool employs a high-voltage transmission of power from a battery pack over a cord to a DC to DC converter, which steps the transmission voltage down to rated tool voltage. The system uses a switching transistor to transmit power according to a duty cycle which varies automatically according to tool current draw and voltage. The DC to DC converter employs synchronous rectification with an inductor-capacitor network to transform a duty cycle square wave into DC power. The startup voltage sense feature permits powering up the converter circuitry only when needed. The converter will shut down if no current has been drawn by the tool for a predetermined period of time or if the converter unit is in danger of overheating, as determined by a stored algorithm. The portable power system has safeguards to prevent fouling or shorting in wet environments, is adaptable to left or right handed users, and is physically configurable into a variety of carrying modes.

Abstract: There is provided an electronic inductance circuit having a transistor, a first resistor, a second resistor, a capacitor and a first current source. The main current path of the transistor and the first resistor are connected in series to form a first serial circuit between an input terminal and an output terminal. The second resistor and the capacitor are connected in series to form a second serial circuit between the input and output terminals, thus forming a parallel circuit of the first and second serial circuits. The connection point between the second resistor and the capacitor is coupled to the control terminal of the transistor. The connection point is connected to the first current source for determining the operating point of the transistor.

Abstract: A method for the low-transient power control of electrical loads, particularly temperature-dependent loads electrically divided into essentially equal sub-loads connectable to an a.c. mains in order to receive power. Power control at low power levels utilizes alternately power-off phases, in which none of the sub-loads receive power for at least three a.c. half-waves, and heating phases, in which a temporal concatenation of at least a first and a second basic cycle of three a.c. half-waves supply power to each one of the sub-loads. The first sub-load receives power during one half-wave of the first basic cycle and the second sub-load receives power during one half-wave of the second basic cycle. The power is turned off during the other two half-waves of the first and the second basic cycle. Also disclosed is an electrical heating apparatus which embodies this method.

Abstract: Briefly, in accordance with one embodiment of the invention, a circuit includes a DC-to-DC converter. The DC-to-DC converter includes a high-side field effect transistor (FET) and FET driver. The gate of the high-side FET is AC coupled to the FET driver. The gate-to-source electrical path of the high-side FET is coupled to be driven by a substantially fixed voltage during circuit operation.

Abstract: For use with a power converter coupled to a regulation circuit and having a power switch and an auxiliary switch coupled thereto, a controller, method of operating the power switch and auxiliary switch and a power converter employing the controller and method. In one embodiment, the controller includes a voltage conditioning network, parallel-coupled to the power switch, capable of sensing a voltage across the power switch and developing a conditioned voltage. The controller further includes a drive circuit, coupled to the voltage conditioning network, adapted to provide a drive signal to control the auxiliary switch as a function of the conditioned voltage and a regulation control signal from the regulation circuit.

Abstract: A load transient compensator and method of operating the load transient compensator for reducing the transient response time to a load capable of operating at either of several consumption levels when the load changes its power consumption level. The load transient compensator has a comparator having an output connected to an input of an upper driver and of a lower driver with the output of each of the driver being connected to a gate of a power transistor. When the load is in sleep mode and is about to start being accessed, the upper driver is turned on to turn on its associated transistor to supply additional current to the load, regulated by the comparison circuit. When the load is in the power up mode and it is about to stop being accessed, the lower driver is turned on to turn on its associated transistor to drain current supplied to the load by a supply, regulated by the comparison circuit.

Abstract: A system to control the output voltage of a power converter in response to a specific load battery condition. The system contains a power converter, a TCMS interface attached thereto and a controller for selectively and/or adaptably changing the magnitude of converter output voltage. A control module is incorporated in the system to automatically change converter output voltage up or down in response to the load (input) voltage. The module contains a microcontroller to sense the battery (input) voltage process said input voltage with an analog-to-digital converter. The microcontroller is programmed to execute a series of routines to determine the proper charging voltage for the system. Thereafter, the control module communicates this information through the interface of the power converter to cause the power converter to charge at the optimum voltage. In the alternative, a plug-in component containing passive circuitry may be used to manually signal the power converter to charge at a predetermined voltage.

Abstract: A digital control circuit is used for controlling the load current of a power converter circuit (102), and comprises a reference circuit (302), analog comparator circuit (304), control logic circuit (306), and a counter circuit (308). The control logic circuit controls the operation of a power switch (110), and uses counters (314, 316) in conjunction with the analog comparator circuit and reference circuit, to determine when to open and close the power switch. The load current is allowed to vary between a first and second preselected load current levels.

Abstract: A buck boost switching regulator includes a buck switch and a boost switch controlled by a first and second comparator, respectively. The first comparator generates a duty cycle control signal for the buck switch in response to the difference between the regulator output voltage and a control voltage corresponding to a desired regulator output voltage. The second comparator generates a duty cycle control signal for the boost switch in response to a supply voltage.

Abstract: A power-supply circuit having a switching regulator (10) and at least one additional circuit (14, 14') whose two respective outputs (11, 17) are guided together to a common or joint output (18) by diodes (D3, D3'; D4). The additional circuit (14, 14') produces, from an alternating quantity (15) occurring inside the switching regulator (10), a second output voltage (U+, U'+) that is in a second output-voltage range and is more positive with respect to the first output voltage (U-) that is made available at the first output (11) of the switching regulator (10) and is in a first output-voltage range. A gas-discharge lamp, for example, is provided as the load (L) between the first and second outputs. The division of the voltage ranges to be made available for the load (L) into at least two partial ranges permits a high effectiveness of the current-supply circuit of the invention.

Abstract: A control circuit for controlling a current switch to provide current to a load circuit, includes a hysteresis trigger circuit arranged to selectively switch on the current switch in dependence upon a control signal. A transistor is arranged to selectively provide an operating current to the hysteresis trigger circuit in dependence upon the control signal. In this way operating current is only supplied to the hysteresis trigger circuit when the control signal is high, such that the load circuit does not draw current when the control signal is low.

Abstract: An apparatus for coupling a battery to a mains-powered Sc link circuit of a converter. The this apparatus has two capacitors and two converter bridge arms which are each connected electrically in parallel with a capacitor. The apparatus also includes an inductor which connects the centre terminals of the two converter bridge arms to one another, and a semiconductor power switch which makes it possible to connect the positive terminals of the two converter bridge arms. In addition, the apparatus includes a control electronics with downstream driver stages which control electronics use determined actual values of this apparatus, a mains failure signal and an inductor current setpointvalue to generate control signals. A battery coupling apparatus is thus obtained by means of which the battery is not continuously loaded with alternating current, and the opportunity for battery maintenance exists in order to increase the battery life.

Abstract: The present invention discloses a low-cost voltage regulator circuit which provides at its output port, from one power source, a voltage of a set of different voltages to a load of electrical energy consuming devices, without power interruption to the load during transition time. The voltage regulator circuit includes a set of relays and a set of step-down transformers. Each of the relays receives a corresponding control signal, the magnitude of which is regulated to control the state of the associated relay. Each of the step-down transformers comprises a primary winding and a secondary winding. The secondary windings of the step-down transformers are connected in series between the positive terminal of the power source and the positive terminal of the output port, while each of the primary windings is coupled to the power source via an associated relay.

Abstract: A DC power converter is disclosed for converting an input voltage to a final output voltage that is higher than the input voltage. The power converter includes an input terminal for receiving the input voltage and a final output terminal. A boost converter generates an intermediate voltage that is higher than the input voltage and lower than the final output voltage. The boost converter includes an inductor having a primary winding that has a first end connected to the input terminal, a switch for selectively connecting the second end of the first winding to ground, a first diode connected between the second end of the first winding and an intermediate node, and a first output capacitor connected between the intermediate node and ground. The boost converter produces at the first output capacitor an intermediate voltage higher than the input voltage. The step up converter described further includes a second winding on the inductor, a first end of which is connected to receive the intermediate voltage.

Abstract: An integrated CPU has an on-board switching voltage regulator with an electrically-erasable programmable read-only memory electronically accessible for storing a feedback reference coefficient for control. In further embodiments, output voltage is tuned via a second EEPROM storing an electronically accessible value in concert with a solid-state resistor ladder. In other embodiments, signals on interrupt lines to the CPU are monitored to provide a prewarning of impending activity by the CPU requiring dramatically increased current flow. In yet other embodiments, solid state circuitry is provided to reduce or eliminate capacitors used for dealing with input current surges to the CPU.

Abstract: A programmable DC-DC converter controller with a high speed synchronous controller and a 5-bit programmable DAC provides an operating voltage to an external device (such as a microprocessor) in response to a 5 bit code programmed in the external device. The 5-bit programmable DAC outputs a signal which provides voltages to the external device in increments of e.g. 50 or 100 millivolts, in respectively two different voltage ranges.

Abstract: A digitally controlled switched-mode voltage converter having conversion circuit (CMS) including a switching device (SW) for the purpose of converting an input voltage (U.sub.i) into an output voltage (U.sub.o); and a control device (CM) for controlling a duty cycle of the switching device (SM) in steps having discrete values (D.sub.c1,D.sub.c2). The control device (CM) include a change-over device (SO) for continually switching the duty cycle between at least two discrete values (D.sub.c1,D.sub.c2) in such a manner that the average value of the duty cycle corresponds to a target duty cycle (T.sub.dc).

Abstract: Synchronous switching regulator circuits with voltage-drop sensing circuitry are presented in which the current sensing element typically in series with a load is eliminated, resulting in reduced dissipative losses and less costly manufacture. Voltage drops are measured across the regulator's synchronous switching element, and, in some cases, also across the regulator's main switching element. Measured voltage drops are used to derive a current analog signal indicative of the amount of current being supplied by the regulator. The current signal is then compared with a threshold value to determine whether the regulator's duty cycle should be varied.

Abstract: A circuit for providing a regulated output voltage from a buck converter without directly monitoring the output voltage. The buck converter includes a switch having a first terminal coupled to a supply voltage and a second terminal coupled to a first terminal of an inductor and to a first terminal of a resistive divider. A second terminal of the inductor is coupled to a first capacitor for forming the output voltage across the first capacitor. A voltage formed by the resistive divider is applied to an inverting input of a transconductance amplifier, while a reference voltage is applied to a non-inverting input of the transconductance amplifier. An output of the transconductance amplifier is coupled to a second capacitor for forming an error signal across the second capacitor. The error signal is representative of a difference between the output voltage and a desired output voltage because an average of the voltage formed by the resistive divider is representative of the output voltage.

Abstract: A buck regulator circuit provides a low voltage, e.g., about 15 V, power source, directly from a variable high-voltage dc bus voltage that varies from 250 V to about 450 V. A monolithic gate driver circuit is used to drive the switching device, e.g., a MOSgate transistor, which delivers the high voltage dc to the load output node via a charging inductor for controlled time periods. The control principle for controlling the on and off times of the transistor (with the monolithic gate driver circuit) relies on turning on the transistor for fixed time periods that are equal to the intrinsic delay of the gate driver circuit. In contrast, the off period of the switching device is varied to regulate and maintain the output voltage at a constant value, independent of the input dc bus voltage or of the output current.

Abstract: In a computer having switch-mode power converter, a pulse transformer circuit drives the converter's transistor switch in response to pulses from a switch control pulse source. A primary capacitor is connected in series with the switch control pulse source and the transformer's primary winding. At the leading edge of a switch control pulse, the primary capacitor causes a positive voltage spike to appear across the primary winding and hence a positive voltage spike to be induced across the transformer's secondary winding. At the trailing edge of the switch control pulse, the primary capacitor causes a negative voltage spike to appear across the primary winding and hence a negative voltage spike to be induced across the transformer's secondary winding.

Abstract: An integrated CPU has an on-board switching voltage regulator with an electrically-erasable programmable read-only memory electronically accessible for storing a feedback reference coefficient for control. In further embodiments, output voltage is tuned via a second EEPROM storing an electronically accessible value in concert with a solid-state resistor ladder. In other embodiments, signals on interrupt lines to the CPU are monitored to provide a prewarning of impending activity by the CPU requiring dramatically increased current flow. In yet other embodiments, solid state circuitry is provided to reduce or eliminate capacitors used for dealing with input current surges to the CPU.

Abstract: A multiple value voltage output circuit in which the number of transistors configuring a high breakdown voltage circuit portion can be reduced so that the area for forming the circuit is reduced. In a signal electrode driving circuit 11, an inverted AC-converting signal FRR inputted to switching control circuits 12 and 13 is selectively inputted to transistors 41 to 44 of an output buffer 14, on the basis of a data signal DA, thereby make one of the transistors 41 to 44 conduct so that a voltage corresponding to the turned-ON of the transistors 41 to 44 is outputted through an output terminal 15.

Abstract: A method for reducing the transient response time of a voltage regulator when the load attached to it is entering or exiting a lower power consumption level by changing the bandwidth of the voltage regulator without compromising its stability, and a bandwidth regulator for implementing such a method are disclosed, wherein the bandwidth of the voltage regulator is changed based on a signal sent by a control device when it senses that the component is about to change power consumption levels.

Abstract: A buck converter comprises a load or a rechargeable battery (B), a self-inductance (L2), a diode (D2) and a switching transistor (T1). The current through the switching transistor (T1) is measured by means of a current sensor (Rs) which triggers a monostable multivibrator (MMV) when a given peak current is reached. The monostable multivibrator (MMV) turns off the switching transistor (T1) for a fixed time within which the current through the self-inductance (L2) is supplied to the load (B) via the diode (D2).

Abstract: An improved power supply for converting any of various standard national AC network voltages to low-voltage DC power suitable for driving a 1 or 2-watt device, such as a fan, features a semiconductor control circuit (18, FET 46) which chops each half-wave of a rectified voltage and uses the low-voltage portions to feed charging current pulses to a storage capacitor. The voltage on the capacitor (14) is used by other portions of the circuit to regulate rotation speed of the fan or other consuming device (40) to a value set on a variable resistor. The use of the low-voltage portions of the input signal reduces power losses and increases efficiency.

Abstract: According to a first aspect of the invention, a power control switch comprises two solid state switching elements (14, 15) in parallel, the second switching element (15) having a higher resistance but faster turn-off time than the first element. In operation the switch is pulse width modulated and the first element is switched off after the second element to establish a guard period, the duration of which is controlled in dependence upon the duty cycle to provide efficient switching. According to a second aspect of the invention a power control switch comprises a switching element (14 or 15) controlled by a field programmable gate array (5) which is preferably programmed by an erasable programmable read only memory (EPROM), thereby providing a reconfigurable control means.

Abstract: A multi-slice power converter (10) employs a digital circuit (22) to generate phase-delayed pulse width modulated (PWM) signals, which results in the duty cycle of the PWM signals having only a certain number of possible values. The quantization of the duty cycle is shown to result in two types of instabilities which are unique to power converters having a digital control loop, in addition to the conventional analog-type of instabilities. This invention provides novel methods and apparatus for stabilizing the digital control loop of the power converter through the use of a periodic dither signal having a frequency that is less than the PWM frequency and greater than a bandwidth frequency of the converter. The dither signal functions to effectively increase the number of possible duty cycles by a factor given by the ratio of the dither frequency to the bandwidth frequency.

Abstract: A regulated power supply provides a regulated supply voltage at a preselected level under normal operating conditions. When power demands of the circuitry driven by the supply requires a higher voltage, the supply adapts to supply such a higher voltage. Such a supply can be used with automotive electronic circuitry, and can supply voltages up to approximately the voltage available on an automobile battery when such higher power demands occur. The higher supply voltages remain regulated, and return to normal levels when the extra power requirement is removed.

Abstract: A pulse width modulation type power supply modulator capable of operating at high switching frequencies (>10 MHz) is achieved by eliminating resonant circuits which limit the maximal switching frequency. The modulator includes a power circuit including a power transistor, a first control circuit connected to the gate of the power transistor and a second control circuit connected to the output of the power circuit. In a preferred embodiment the active components are isolated from each other by areas of metalization on a printed circuit to minimize unwanted coupling and the electrical lengths are minimized.

Abstract: A switched capacitor network includes a switch device alternatingly charging two first capacitors having the same capacitance from a signal voltage source with polarities being opposite relative to a ground potential and then discharging each of the two first capacitors through the input circuit of a respective differential amplifier. The switch device alternatingly charges two second capacitors having the same capacitance in phase opposition with one another from a reference voltage source with the same polarities relative to the ground potential and then discharges each of the two second capacitors through the input circuit of a respective one of the differential amplifiers, in synchronism with the charging and discharging of the two first capacitors.

Abstract: This invention relates to a load driving circuit having a fail-safe breaking mechanism for breaking a primary power source when a failure occurs. This invention also relates to a load driving circuit capable of saving electricity in driving an inductive load and reducing a delay in stopping the load. The breaking mechanism for breaking the primary power source has no contact. The load driving circuit includes a power supply circuit involving a semiconductor switching element that turns ON and OFF the supply of power to the load. There is arranged a detector for detecting a failure in the semiconductor switching element. When detecting a failure, the detector provides an output signal to activate the breaking mechanism. To drive the inductive load, the power supply circuit may have two power supply sources. In response to a load driving instruction signal, the two power supply sources together apply a high voltage to the load.