Abstract: An example controller includes a fault detector and a control. The fault detector is to be coupled to a feedback circuit of a power converter to detect a fault condition in the power converter in response to an input voltage of the power converter. The control is coupled to the fault detector and is to be coupled to control the switching of a power switch to regulate an output of the power converter. The control is coupled to inhibit the switching of the power switch in response to the fault detector detecting the fault condition during the switching of the power switch.

Abstract: A startup circuit for providing a startup voltage from a high voltage DC bus voltage to an application circuit including an integrated circuit package for at least a control circuit for driving at least one power switch of the application circuit; a dropping resistor in the integrated circuit package having a first terminal for coupling to the high voltage DC bus and for dropping the high voltage DC bus voltage to a reduced voltage level at a second terminal; and a low voltage regulator in the package coupled to the second terminal for providing a startup regulated low voltage DC output at a preset level for powering at least one part of the application circuit during startup of the application circuit. The application circuit may be, for example, a switching mode power supply.

Abstract: A DC-DC converter system is provided to improve switching control operation of a battery charging DC-DC converter (3) in an overheat temperature state without necessitating complication of a control unit (4). The control unit (4) performs output voltage limitation as well as output current limitation when the temperature of the DC-DC converter (3) is in an overheat temperature state in the vicinity of its operation stop temperature. With this capability, the output current and the output voltage can be limited, and therefore overheating of a power switching device (32) of the DC-DC converter (3) can be inhibited. In an alternative embodiment the switching frequency of the power switching device (32) is limited.

Abstract: The present invention provides a method and a control circuit to detect an input voltage for the control and protections of a power converter. It includes a current sense circuit for generating a current signal in response to a switching current of a transformer. A detection circuit is coupled to sense the current signal for generating a slope signal in response to a slope of the current signal. A protection circuit is further developed to control the switching signal in accordance with the slope signal. The level of the slope signal is corrected to the input voltage of the power converter.

Abstract: The switching power supply apparatus includes detection means for detecting that leak current of an input smoothing capacitor becomes a predetermined value or more and first auxiliary switching means connected in series with respect to the input smoothing capacitor. The first auxiliary switching means becomes an on state during a normal operation, whereas the first auxiliary switching means goes into an off state in a case where the detection means detects that the leak current of the input smoothing capacitor becomes a predetermined value or more.

Abstract: The switched mode power supply comprises an inductor, a switching transistor, a controller circuit coupled to the switching transistor, a rectifying means and a feedback regulation loop for providing a stabilised output voltage. It comprises further a protection circuit coupled to an output or input of a comparator of the controller circuit for providing an overvoltage protection in case of a failure of the regulation loop. The protection circuit comprises in particular an integrating circuit and a comparating circuit. In a preferred embodiment, an output of the protection circuit is coupled to a sense input of the controller circuit, for switching off the controller circuit immediately in case of a failure. In another aspect of the invention, the protection circuit comprises further a second comparator coupled to the first comparating circuit for the surveillance of the input voltage of the switched mode power supply, and for the detection of a short circuit of the inductor or the rectifying means.

Abstract: There is described a method for controlling a quenching device for a converter bridge with line regeneration, whereby the converter bridge controlled by a network-timed control circuit by ignition pulses is connected with its three inputs to the phases of a three-phase network and the two outputs of the bridge are connected to a direct-current motor which feeds, when operated as a generator, current back to the three-phase network via the bridge. The quenching device is controlled by a trigger unit which emits trigger pulses depending on the monitoring of electrical and temporary variables. The quenching device comprises, for each bridge half, a quenching condenser that can be charged by a charging circuit quenching voltage. The quenching condensers, in the event of quenching, can be connected to the bridge halves by means of switches that are controlled by the trigger unit.

Abstract: Disclosed is an invention relating to a power supply for use in an apparatus for measuring electrical energy, comprising, in one embodiment, a first switching device, a device for storing electrical charge in electrical connection with the first switching device, a second switching device in electrical connection with the device for storing electrical charge, a first device for controlling the flow of current in electrical connection with the second switching device, and a third switching device in electrical connection with the first device for controlling the flow of current, wherein the first device for controlling the flow of current enables an input voltage to be applied to the second switching device when the input voltage is below a predetermined amount, and enables the input voltage to be applied to the second and third switching devices when the input voltage is above the predetermined amount.

Abstract: The disclosure relates to a method of detecting the phase-loss state of the three-phase power supply. When the phase-loss condition occurs in the input three-phase power supply of the power converter, it is determined whether the three-phase power source is in the phase-loss state through the characteristic of the frequency and amplitude variations of the ripple voltage of the DC bus, and through the sampling and the continuous detecting of the ripple voltage variations by making use of the sensor of the power converter in cooperation with the software calculation, it is determined whether the three-phase power source is in a phase-loss state. When the detected ripple voltage of the DC bus fulfills the phase-loss conditions, it is determined that the three-phase power source is in a phase-loss state.

Abstract: A method and electrical circuit for dynamic reconfiguration of a DC-to-AC inverter comprising first and second power rails where each the rails has a power source. The method comprises monitoring the first and second power rails for short-circuit failure; and upon failure of one of the power rails, disconnecting the failed power rail from its power source.

Abstract: A method and apparatus for distributing electrical power is provided. In one embodiment, the apparatus includes: a semiconductor switch adapted to receive input power from a DC power source, adapted to distribute power to a DC/DC module, and adapted to receive a control signal, a charge storage device in operative communication with the semiconductor switch and a return path associated with the DC power source, and a reverse current monitoring logic in operative communication with the semiconductor switch. In this embodiment, the reverse current monitoring logic is adapted to detect reverse current flowing in the semiconductor switch and, in response to detecting the reverse current, is adapted to open the semiconductor switch. Several embodiments of a method of distributing electrical power to a DC load are also provided.

Abstract: A circuit for detecting faults in at least one converter in a converter system, the at least one converter including a switching stage having high- and low-side switches connected at a switching node and fault circuitry for managing a plurality of fault conditions. The circuit including a gate driver circuit connected to gate terminals of the high- and low-side switches for providing PWM signals to control the switching stage; a comparator circuit for comparing a voltage at the switching node to the input voltage and providing an output signal, the comparator circuit having output, positive and negative terminals; a fourth capacitor connected to the output terminal of the comparator circuit to generate an AC component of the comparator circuit output signal; and a rectifier circuit connected to the fourth capacitor for rectifying the AC component of the comparator circuit and providing a fault-indicating signal to the gate driver.

Abstract: A DC power conversion circuit having self-auxiliary power and self-protection against a short or open load circuit includes a DC voltage source, a driving circuit, and an auxiliary circuit. The DC voltage source is used for providing a DC power. The driving circuit includes a switch, a first resistor, a control signal generator, a second resistor, a diode and an inductor. The switch is used for conducting or cutting off an electrical connection according to an incoming control signal. The control signal generator senses voltage of the first resistor to generate the control signal. The inductor is coupled between the first resistor and a load circuit. The auxiliary circuit is parallel to the inductor and includes an auxiliary capacitor and an auxiliary diode. The auxiliary capacitor is coupled between the first resistor and the second resistor. The auxiliary diode is coupled between the inductor and the auxiliary capacitor.

Abstract: An electronic ballast circuit for a lamp is described, wherein the ballast comprises a power factor correction circuit coupled to an inverter circuit. The inverter circuit is further coupled to a trigger circuit, which is in turn operatively connected to a hot or neutral line of a power supply by a control line. Upon closing a switch in the control line, the trigger circuit operates to place a capacitor in parallel with a base drive winding of a transistor in the inverter circuit, causing the inverter circuit to shut down. When the switch is opened, the trigger circuit shuts off and the inverter starts up and returns to an oscillating state.

Abstract: Self-powered supplies are presented for powering a power converter switch driver with power obtained from an associated snubber circuit, in which a supply circuit and a snubber circuit are connected in a series path across the switch terminals with the supply circuit receiving electrical power from the snubber and providing power to the switch driver.

Abstract: A drive for delivering a high-power signal to a load includes a power circuit and a drive circuit. The power circuit is operable to provide a high power signal to the load in response to a control signal. The control circuit is operable to generate the control signal for activating the power circuit. The control circuit includes an application processor and a safety circuit. The application processor is operable to generate the control signal during a normal mode of operation. The safety circuit is operable to inhibit the generation of the control signal during a safe-off mode of operation. The safety circuit includes a safety processor independent from the application processor and operable to monitor the safety circuit.

Abstract: A pulse width modulation inverter circuit is provided. The circuit includes a power switch driver, a power switch, a transformer unit, a feedback detector unit, and a voltage control oscillator. The circuit is electrically coupled to the DC power source to drive a load. The circuit adjusts the pulse width of the signal outputted from the power switch driver according to the voltage inputted to the DC power source. Accordingly, the circuit can maintain a fixed input voltage received by the fluorescent tube. Thus, the high input voltage but low output phenomenon can be avoided.

Abstract: The H-bridge circuit with shoot through current prevention during power-up includes: a high side transistor; a low side transistor coupled in series with the high side transistor; pull down devices coupled to a control node of the high side transistor and to a control node of the low side transistor; and wherein the pull down devices are controlled by a pull down circuit including a Power On Reset circuit, monitoring the digital power supply such that the high side and low side transistors are OFF until the digital power supply has settled to a desired operating voltage.

Abstract: A new type of the passive non-dissipative snubber with a single saturable reactor improves the performance of the boost converter used as a front-end active Power Factor Correction (PFC) in two critical areas: excess voltage stresses caused by high voltage spikes on input high voltage switching transistor of the boost converter is eliminated and EMI noise is much reduced. The high voltage spike energy instead of being dissipated as in a dissipative snubber circuits is recovered resulting in increased conversion efficiency. High voltage spike elimination also allows use of lower voltage rated devices with lower ON resistance, hence further increasing the efficiency of the PFC boost converter.

Abstract: A first to an n-th current sources supply a first to an n-th charging currents, respectively. A sequence control circuit allows an x-th charging current of the first to the n-th charging currents to charge a capacitor for generating an x-th soft-start signal. The variable x is an integer and satisfies an inequality of n?x?1. Before a y-th charging current is allowed to charge the capacitor for generating a y-th soft-start signal, the sequence control circuit stops charging the capacitor by the x-th charging current and discharges the capacitor toward a ground potential. The variable y is an integer different from the variable x and satisfies an inequality of n?y?1.

Abstract: The present invention relates to a drive circuit for a switch (T) connected to a rectifier arrangement in a switching converter which provides an output voltage (Vout) from an input voltage (Vin), the drive circuit having the following features: a controller arrangement (40) having at least one control amplifier (OTA1) and a compensation network (41) having at least one capacitor (C4, C5), a signal dependent on the output voltage (Vout) being fed to said controller arrangement and the latter providing a control signal (S4), a protection circuit (30), which is designed to detect at least one critical state of the switching converter and which provides a protection signal (S3) in a manner dependent on the presence of a critical state, the protection circuit (30) having a discharge circuit (32) coupled to the compensation network (41), a signal generating circuit (20), to which the control signal (S4) and the protection signal (S3) are fed and which provides a drive signal (S5) having drive pulses according t

Abstract: A circuit for reducing inrush current generated during startup of a switching power supply, which includes a reference voltage generator, an error amplifier, an oscillator, a sawtooth wave generator, a PWM comparator, an overshoot comparator, an AND gate, a R-S flip-flop, a power MOS switch, and a rectifying and filtering circuit. A division voltage outputted from the rectifying and filtering circuit is fed to the error amplifier.

Abstract: An inrush current prevention circuit for a DC-DC converter is provided and in preferred aspects comprises a switching element that transforms an input voltage by being switched on and off and outputs the transformed voltage. A filter filtrates the outputted voltage, transformed via the switching element, and outputs the filtrated voltage as an output voltage. A reference voltage generator generates a reference voltage. An error amplifier compares the reference voltage and output voltage and outputs an error signal. A Pulse Width Modulation (PWM) signal generator generates a PWM signal to switch on and off the switching element according to the error signal. An on-off circuit either transmits or isolates the PWM signal to the switching element. An Electronic Control Unit (ECU) controls the on-off circuit. Preferred systems of the invention can prevent an inrush current immediately following power input or during reactivation of the DC-DC converter.

Abstract: A computer power supply with a display function has a rectifying circuit, an EMI filter, a power factor corrector, a switching circuit, a transformer and a secondary coil voltage regulator located between an AC voltage input and a DC voltage output. A linear rectifying circuit as a major technique connects to the output of the power factor corrector to detect power dissipation and represent the result in a display, thus user can take necessary measures when a computer draws excessive power.

Abstract: A power circuit for an electronic machine includes first and second step-up circuits, and a voltage applier. The first step-up circuit has a step-up transformer and a current controller. The current controller controls the amount of current supplied to the primary side of the step-up transformer according to the amount of voltage at the secondary side of the step-up transformer, so that the voltage applied to the primary side of the step-up transformer by a D.C. power source is stepped up to a first voltage. The second step-up circuit steps voltage applied by the D.C. power source up to a second voltage being smaller the first voltage. The voltage applier applies the second voltage to the secondary side of the step-up transformer. The current controller controls the amount of current supplied to the primary side of the step-up transformer according to the second voltage when the first step-up circuit starts, so that rush current caused by starting the first step-up circuit is restrained.

Abstract: In a power supply circuit, a main transistor, which transmits power from an input terminal to an output terminal, is controlled so that a detected voltage from an input voltage is consistent with a reference voltage indicating a target voltage. An output current is detected and a limited value of the output current is set so that the limited value increases gradually when the output voltage rises up to the target voltage. The main transistor is controlled so that the output current keeps a value less than or equal to the limited value. This configuration is able to suppress an overshoot of the output voltage, thanks to a gradually raised control of the limited value. Additionally, to avoid the influence of a ringing component of the input voltage, a delay control circuit to give a delay to the start of rise of the output voltage can be provided.

Abstract: EMI noise in a system using a power converter with switching control is reduced in a simple configuration. The power converter 3 includes a converter 31, a smoothing capacitor 32, and an inverter 33, and receives the power from an AC power supply 1 via an AC reactor 2 and converts it into a power of an optional frequency and voltage to supply to a motor 4. Damping impedance elements 6, 7, 8 are inserted between the frame of the motor 4 and the ground 5, between the cooling fin 34 of the power converter 3 and the ground 5, and between the AC reactor 2 and the ground 5, respectively. Further, paths between the AC reactor 2 and ground 5, between the power converter 3 and ground 5, and between the motor 4 and ground 5 are insulated except that the damping impedance elements 6, 7, 8 are inserted.

Abstract: A power switching circuit comprising a first power switching device the first power switching device having a control electrode and two main current carrying electrodes, a sense circuit for providing a signal proportional to the current through the first power switching device and an active clamp circuit connected to said control electrode of said first power switching device, wherein said active clamp circuit provides a variable clamp voltage between one of the main electrodes of the first power switching device and the control electrode when the current in the first power switching device exceeds a threshold level the variable clamp voltage being related to current through the first power switching device.

Abstract: In a power converting apparatus including a capacitor connected in series which serves to divide a DC voltage, and a PWM inverter bridge for converting the DC voltage into an AC phase voltage having three electric potentials of a positive voltage, a negative voltage and an intermediate voltage in a plurality of phases, a zero voltage period generator (11) is switched by signal switching devices (5 to 10) when a load current reaches a first overcurrent level based on the detection of an overcurrent detector (12), and there is provided a zero voltage period having an intermediate voltage in which output phase voltages having all phases of the power converting apparatus become the intermediate voltages, thereby carrying out a current limitation. With an inexpensive structure, consequently, a rapidly increased current in an inverter can be instantaneously suppressed at time of the detection of an overcurrent.

Abstract: A self-excited switching power supply circuit is provided which reduces a discharge current generated when an oscillating field effect transistor (3) is turned on, whereby it is possible to reduce energy loss and generation of noise when switching is executed. A time constant of an ON-control circuit (12, 23) is set such that when a polarity of a voltage of a feedback winding (2b) has reversed, a gate voltage of the oscillating field effect transistor (3) exceeds a threshold voltage VTH. Accordingly, after a voltage of a primary winding (2a) has become equal to or less than a power supply voltage, the oscillating field effect transistor (3) is turned on, and electrical charge stored in stray capacitance between the windings of the primary winding (2a) and in parasitic capacitance of the oscillating field effect transistor (3) is discharged gradually.

Abstract: A power fluctuation inhibiting device for effectively inhibiting fluctuation of power supply voltage that is supplied to internal circuits. The inhibiting device includes a power fluctuation measuring circuit for measuring peaks in the fluctuation of the power supply voltage produced when the internal circuits are operated. A clock signal control circuit adjusts phases of clock signals provided to respective ones of the internal circuits in accordance to the peak measuring result to substantially offset the fluctuation peaks produced when the internal circuits are operated.

Abstract: Disclosed are methods and apparatus for over-current detection in PWM power stages. Disclosed methods and apparatus provide over-current detection with adaptive filtering according to the pulse width of the PWM input signal. Methods and apparatus for their implementation are described for detecting the pulse width of a PWM signal in the PWM circuit. According to the detected pulse width, a digital delay less than the pulse width of the PWM signal is selected from among a plurality of available digital delays. Further, an over-current condition in the PWM power stage is detected. The detected over-current signal is filtered by means of the selected digital delay and an over-current detection result is output.

Abstract: A generating set includes an engie driven generator (PGM) having two sets of stator windings (Ga and Gb). A bi-directional AC/DC converter (BCo) has its AC input connected to a junction between the two sets of stator windings (Ga and Gb) and its DC input connected to a number of the generator (PGM) is converted into an intermediate DC link by a convertor (Col) to produce an output for a load Lo. In normal operation of the system, an emf generated in one (Ga) of the sets of stator windings is rectified by the bi-direcitonal converter (BCo) to charge the energy storages (ESI-ESN) whilst the remainder of the generator output is fed through the converter to the load (Lo). In the event of a stepped increase in the load demand, the bi-directional converter (BCo) is operated to feed energy from the storage devices (ESI-ESN) to the stator windings (Ga) of the generator (PGM) to impart a driving torque to the generator rotor to accelerte the rotor to meet the increased load demand.

Abstract: An external power source control system for a portable telephone includes: a regulator 5 connected at an input thereof to a battery power source 1 or an external power source 2 and outputting a power supply voltage; a one-shot pulse generating circuit 6 generating a one-shot pulse when the external power source 2 is connected to the portable telephone; a reset circuit 7 outputting a reset signal when the power supply voltage reaches a predetermined threshold level; and a controller maintaining an output of the power supply voltage from said regulator 5, based on the one-shot pulse, and canceling the maintenance of the output of the power supply voltage from said regulator 5, based on a predetermined instruction indicating that the power is not necessary.

Abstract: There are disclosed a synchronous rectifying type of DC—DC converter, a DC—DC converter control circuit constituting such a type of DC—DC converter, a monitor circuit for monitoring an operation of a DC—DC converter, and an electronic equipment having a DC—DC converter, considering a conduction current. A DC—DC converter has a main switch and a synchronous rectifying switch, in which said main switch and said synchronous rectifying switch are alternately turned on so that a voltage of a DC electric power is transformed and outputted. A state that said main switch and said synchronous rectifying switch are simultaneously turned on is detected.

Abstract: There is disclosed a switching mode power supply with a reduced EMI effect, comprising a rectifier for converting an AC power supplied by an AC power source into a rectified DC power, a transformer coupled to the rectifier for inputting the DC power from a primary winding and inducing a rectified power to a secondary winding through the primary winding, a switch unit connected in series with the primary winding for converting the DC power supplied to the primary winding into AC power by on/off operations, an output voltage feedback control circuit for providing pulses to drive the switch unit by controlling a switching duty cycle of the switching unit, and a power line filter including a unidirectional current-limiting device such as a diode for reducing differential mode noise appearing between a live supply line and a neutral line from the alternating current power source.

Abstract: An integrated circuit (IC) chip provided with a ‘power-save’ switch, including MEMS (Micro-Electro-Mechanical Systems) switches in each power and ground ring, to be used to open the circuit and eliminate power drain. The MEMS switches preferably include a cantilevered beam deflected by an electrostatic charge. When the equipment of which the IC forms a part is put on standby, it enters a low-power mode in which the ‘power-save’ switch in each IC is actuated by a small control circuit that remains powered up. The MEMS switches are preferably latched into position at least when in the open position, for example by using an permanent magnet, so that no power is consumed by the open switches. The invention is applicable to chips used in wireless mobile terminals, where power consumption is critical, and in any application where it is necessary to enter a standby mode between uses.

Abstract: An improved active voltage positioning (AVP) implementation for a power supply for a microprocessor or the like includes an AVP circuit which is separated from the power supply error amplifier by a buffer amplifier having a parallel RC feedback circuit to controllably adjust the transient response. An AVP signal derived from an output load current sensing element provides an input to the buffer amplifier. A second input is provided by power supply reference voltage. A output of the buffer amplifier is connected as an input to the error amplifier to provide the AVP window. This permits separate adjustment of the transient behavior of the error loop and the AVP loop.

Abstract: An off-line non-step adjustment voltage regulator. The inventive voltage regulator employs a high frequency switch mode to perform the electricity transformation in a converter, and employs an appropriate micro-processing control to couple the energy of the converter to an output end via a transformer so as to form a serial increasing/decreasing effect. Then, an output voltage is output, and is sent to a control circuit. The output voltage will be compared with a reference value so as to control the stability of the output voltage. Therefore, the invention can achieve the objective of performing efficiently, saving energy and precise non-section adjustment voltage regulation so as to reduce the system cost. Furthermore, the inventive voltage regulator is suitable to each stage of the voltage regulation equipments with different capacities.

Abstract: A method for ground potential monitoring of a rectifier drive, having a capacitor which is connected with a voltage source via a switching device. The method including applying a test voltage between a connector of a capacitor of a rectifier drive and a mass or ground potential prior to connecting the rectifier drive with a voltage source that is connected with the capacitor via a switching device. The method also includes releasing the switching device if a potential of the connector changes by a predetermined amount after the applying the test voltage.

Abstract: A method for current limiting of an output of a DC-to-DC converter begins by determining a current loading duty cycle of the output of the DC-to-DC converter (i.e., the present duty cycle given the loading of on the output). The processing then continues by comparing the current loading duty cycle with a zero loading duty cycle of the output (i.e., the duty cycle when the output has no load). The processing continues by limiting duty cycle of the output to the zero loading duty cycle plus a duty cycle loading offset when the current loading duty cycle exceeds the zero loading duty cycle plus the duty cycle loading offset.

Abstract: A power converter apparatus includes an input port and an output port. First and second inductors are coupled to the output port. A first switching circuit is coupled to the input port and the first inductor. The first switching circuit is operative to repetitively perform a cycle including a first state in which the first switching circuit couples the first inductor to the input port such that energy is transferred from the input port to the first inductor, a second state in which the first switching circuit short circuits the first inductor, and a third state in which the first switching circuit decouples the first inductor such that energy is transferred from the first inductor to the output port. A second switching circuit is coupled to the input port and the second inductor and implements a similar cycle. The second switching circuit may operate such that the first and second states of the second switching circuit substantially coincide with the third state of the first switching circuit.

Abstract: A switched mode controller for properly handling an under-voltage condition in a power line which includes a current mirror for receiving current from the power line; a reference current source coupled to the current mirror for supplying a reference current; and a power transistor coupled to the reference current source, the power transistor generating a pulse width modulated signal when current from the power line exceeds the reference current, the power transistor being disabled when current from the power line is less than the reference current.

Abstract: A protection circuit and method are provided for a floating power transfer device having one or more switches for controlling charging of a reservoir capacitor across which a load is applied when in use. The protection circuit includes a control circuit, a fault detection circuit and a precharge driver circuit. The control circuit at least partially controls switching of the at least one switch, while the fault detection circuit detects when a fault in the floating power transfer device or the load occurs and sends a fault detect signal to the control circuit in response thereto. The precharge driver circuit, which is enabled by the control circuit responsive to receipt of the fault detect signal, attempts to precharge the reservoir capacitor to a voltage level sufficient for switching of the one or more switches to proceed without damaging the switches.

Abstract: A device includes a governor for controlling the frequency of the generator of a private power generation equipment, function generating means having a function characteristic for detecting the frequency variation rate of the generator and outputting a large output to the value thereof, effective power adjusting means for outputting an output proportionate to the signal, and protective relays for sensing abnormality of the frequency variation rate of the generator, so that, by making the signal in which an output from the function generating means and an output from the effective power adjusting means are synthesized an instruction signal of the governor, and shifting the frequency variation rate of the generator to a level sensed by the protective relays by the function characteristic of the function generating means at the power outage on the alternating current power line side, to detect the power outage on the alternating current power line side.

Abstract: Disclosed is a parallel power source system which has a plurality of power supply units connected in parallel to one another and is designed in such a way that a voltage loss in an inverse-current preventing circuit provided in each power supply unit is reduced, the flexibility of the system design including lengths of power source wirings is maintained and when a short circuit failure occurs in some power supply unit, power supply from the other power supply units continues stably without significantly changing a voltage supplied to a load. The inverse-current preventing circuit comprises an MOS transistor that is intervened in series in an output path in each power supply unit and forms a switch circuit which is normally on, and a potential difference response circuit which operates to turn off the MOS transistor when a potential on the current-output side of the MOS transistor becomes greater than a potential on the current-input side thereof by at least a given amount.

Abstract: An apparatus for compensating for the effects of resonance in an integrated circuit's power distribution network is provided. A resonance detector monitors transmissions from the integrated circuit for certain bit patterns that may excite the power distribution network at a specific frequency and cause power supply resonance. Power supply resonance causes an increase in power supply impedance. When offending transmissions are detected, the resonance detector activates a damping element on the integrated circuit which dampens the resonance. The damping element is a resistive device between two power supply lines that decreases power supply impedance when activated.

Abstract: A fault detection system detecting malfunctions or deteriorations, which may result in an inverter fault, is provided. The system has a temperature sensor installed on a semiconductor module to monitor a temperature rise rate. It is judged that an abnormal condition has occurred if the thermal resistance is increased by the deterioration of a soldering layer of the semiconductor module or by drive circuit malfunctions and, as a result, the relation between an operation mode and the temperature rise rate falls outside a predetermined range.

Abstract: In an electric power source for supplying an electric power from a battery to an electric power line with boosting a voltage generated by the battery so that the electric power of boosted voltage is supplied to the electric power line, a main switch device prevents the electric power supply into the electric power line from the electric power source and the electric power supply from the electric power line into the electric power source in a case in which the boosted voltage to be supplied to the electric power line is less than a target voltage not less than a voltage of the electric power line, while allowing the electric power supply into the electric power line from the electric power source when the boosted voltage to be supplied to the electric power line is not less than the target voltage.

Abstract: A disconnection detecting circuit includes switches for setting a detection signal to be supplied for a signal line, a resistor for supplying the signal line with the detection signal set by the switches and control means for controlling the switches to set the detection signal to be supplied for the signal line and judging whether there is disconnection or not in the signal line on the basis of a change in the detection signal.