Abstract: A switch mode power supply apparatus includes a transformer, a main switching device to adjust a power supply supplied to a primary coil of the transformer, an active clamping circuit to suppress a voltage stress of the main switching device, and a control circuit to control a clamping operation of the active clamping circuit when the switch mode power supply apparatus is in a standby mode. Therewith, it is possible to significantly reduce power consumption of the switch mode power supply apparatus in the standby mode and improve efficiency of the switch mode power supply apparatus.

Abstract: System and method for protecting a power converter. A system includes a threshold generator configured to generate a threshold signal, and a first comparator configured to receive the threshold signal and a first signal and to generate a comparison signal. The first signal is associated with an input current for a power converter. Additionally, the system includes a pulse-width-modulation generator configured to receive the comparison signal and generate a modulation signal in response to the comparison signal, and a switch configured to receive the modulation signal and adjust the input current for the power converter. The threshold signal is associated with a threshold magnitude as a function of time. The threshold magnitude increases with time at a first slope during a first period, and the threshold magnitude increases with time at a second slope during a second period. The first slope and the second slope are different.

Abstract: A switching mode power supply with a multi-mode controller is provided. The switching mode power supply may include a transformer having a primary winding and a secondary winding to supply power to a load. A feedback circuit may be included to generate a feedback signal that varies in relation to the load on the secondary winding. The multi-mode controller may include a switching circuit, a frequency control circuit and a current limiting circuit. The switching circuit may be coupled to the primary winding to control current flow through the primary winding. The frequency control circuit may control a switching frequency of the switching circuit based on the feedback signal. The current limiting circuit may limit current flow through the primary winding by causing the switching circuit to suspend current flow through the primary winding when the current reaches a peak current limit that is set based on the feedback signal.

Abstract: A start-up circuit to discharge EMI filter is developed for power saving. It includes a detection circuit detecting a power source for generating a sample signal. A sample circuit is coupled to the detection circuit for generating a reset signal in response to the sample signal. The reset signal is utilized for discharging a stored voltage of the EMI filter.

Abstract: According to prior art, a clock frequency increase for clocked high-frequency integrated circuits, in particular microprocessors, reaches a current physical limit of approximately 3 GHz, as dynamic current modifications cannot be sufficiently compensated. The aim of the invention is to provide a power supply for electronic systems with a double-figure GHz range. To permit the rapid compensation of dynamic current modifications, the current compensation circuit (10) is placed in the vicinity of the integrated circuit (11) or is integrated into the latter. A control amplifier (8) influences a pulsewidth modulator (2) by means of an optical coupler (9). Said pulsewidth modulator control controls a normal mode voltage converter (3, 4) with synchronous rectification (5). A specific application area for the invention is the supply of future high-performance microprocessors, whose development has been delayed by the aforementioned power problem.

Abstract: An apparatus, device, and system for generating an amount of output power in response to a direct current (DC) power input includes a configurable power supply, which may be electrically coupled to the DC power input. The configurable power supply is selectively configurable between multiple circuit topologies to generate various DC power outputs and/or and AC power output. The system may also include one or more DC power electronic accessories, such as DC-to-DC power converters, and/or one or more AC power electronic accessories such as DC-to-AC power converters. The power electronic accessories are couplable to the configurable power supply to receive the corresponding DC or AC power output of the configurable power supply.

Abstract: A current mirror apparatus includes an input stage receiving an input current, Iin, and no additional bias current. The apparatus includes at least one output stage coupled to mirror the input current as an output current Iout. The input and output stages include insulated gate transistors. A minimum required voltage drop (Vin) across the input stage is approximately 2Von+2Vth, wherein Vth is a threshold voltage of a selected one of the insulated gate transistors, wherein Von is a drain-to-source saturation voltage of the selected transistor. A minimum required voltage drop (Vout) across the output stage is approximately 2Von.

Abstract: A power supply includes a power source having at least one power source output, and a plurality of drivers connected to the at least one power source output. At least one of the plurality of drivers includes a bridge network having a first switch, a second switch and a bridge network output. The first switch is connected between the at least one power source output and the bridge network output. The second switch is connected between the bridge network output and a ground. The bridge network further includes at least one control input connected to the second switch. The bridge network is adapted to change a state of the first switch based on a state of the second switch.

Abstract: A voltage compensation circuit is disclosed for proving an elevated output AC voltage upon an under voltage input AC voltage condition. The voltage compensation circuit comprises an autotransformer having a first and a second autotransformer winding. A first position of a switch connects the first autotransformer winding to the input AC voltage for providing an elevated output AC voltage at the second autotransformer winding. The second position of the switch shorting the first autotransformer winding for providing a non-elevated output AC voltage.

Abstract: In a buck-boost converter, the method compensates for the boost mode power switch having a minimum on-time when entering the buck-boost mode from the buck mode by immediately decreasing a duty cycle of the buck mode power switch upon entering the buck-boost mode. This prevents the inductor current from being higher at the end of the switching cycle than at the beginning of the cycle, so the output voltage stays regulated without the converter oscillating between the buck mode and the buck-boost mode. The duty cycle of the buck power switch is increased in the buck-boost mode as the input voltage further falls and the boost power switch duty cycle is increased. Upon transitioning into the boost mode, the duty cycle of the boost power switch is immediately reduced to compensate for the buck switching being stopped and the buck power switch having a minimum off-time.

Abstract: A voltage supply incorporates two voltage supplies connected in a mirror-image series arrangement to generate a DC voltage between the respective common terminals of the voltage supplies.

Abstract: A control device for a rectifier of a switching converter, the converter powered by an input voltage and suitable for providing an output current. The rectifier is suitable for rectifying an output current of the converter and includes at least one transistor. The control device is suitable for driving the at least one transistor. The control device has a first circuit suitable for identifying the start and the end of every converter switching half-cycle and measuring the duration thereof, a second circuit suitable for generating a signal for turning on the transistor after a given number of measured converter switching half-cycles and when the output current of the converter becomes greater than a reference current.

Abstract: A switching power source device which has main switch elements which switch a current path of the series resonant circuit, and a transformer which induces a current to a secondary side, controls the main switch elements on a primary side. Synchronous rectification switch elements are turned ON and OFF in response to one of the main switch elements. A synchronous control circuit which turns the synchronous rectification switch element ON in synchronization with an ON timing of the main switch element, or a conduction timing of internal diodes in the synchronous rectification switch elements detected by an inter-terminal voltage signal of the synchronous rectification switch element, whichever timing is later, determines a maximum ON width of the synchronous rectification switch element in accordance with a delay time of the conduction timing of the internal diodes with respect to the ON timing of the main switch element.

Abstract: A programmable current mirror a reference transistor, first and second mirror transistors, and a first current bypass. The reference transistor has a source and a gate coupled to a reference current node. The first and second mirror transistors are coupled together in series at a first node. Each of the first and second mirror transistors having gates coupled to each other and to the gate of the reference transistor. The first current bypass including a switch disposed in parallel with the second mirror transistor. The first current bypass is coupled to a source and a drain of the second mirror transistor and to the first node.

Abstract: A one-phase static var compensator apparatus includes a compensator string consisting of a first static var compensator connected serially to a thyristor valve. The compensator string is arranged to be connected on its first end to one phase of a transmission grid of a rated voltage exceeding 69 kV. Moreover, the thyristor valve includes a plurality of thyristors connected serially and the compensator string is arranged to be directly connected to the transmission grid. A corresponding three phase apparatus is also presented.

Abstract: A DC-DC converter including a Pulse Width Modulation (PWM) controller for converting an input voltage into an output voltage is provided. The PWM controller includes an error amplifier, a comparator, a PWM generator and a ramp generator. The error amplifier generates an error signal according to a difference between a reference voltage and the output voltage. The comparator compares the error signal with a ramp signal to generate a trigger signal. The PWM generator generates a PWM signal with a fixed turn-on time, wherein a frequency of the PWM signal is adjusted according to the trigger signal, the input and output voltages. The ramp generator generates the ramp signal according to the PWM signal, the input voltage and the output voltage.

Abstract: A power supply for a negative voltage load has a switch-mode power unit, a monitoring unit, a first auxiliary power unit and a second auxiliary power unit. The switch-mode power unit has a rectifying circuit, a power factor correction circuit, a DC to DC power circuit. The first auxiliary power unit is connected to output terminals of the power factor correction circuit and converts DC power to a first DC power for driving the monitoring unit. The second auxiliary power unit is connected to the negative voltage load in parallel and converts negative power from the negative voltage load to a second DC power for driving the monitoring unit when AC power is interrupted. Since the first and the second auxiliary power unit do not work at the same time, the power supply can effectively enhances the conversion efficiency of the power supply.

Abstract: A method of operating an inverter for converting direct voltage into alternating voltage. The inverter has direct-voltage terminals and alternating-voltage terminals and a plurality of power switching elements that are clocked at high-frequency connected between the d.c. and a.c. terminals. The high-frequency clocking of the power switching elements of the inverter is switched off around a zero transition of the alternating current or the alternating voltage for a period which depends on the direct voltage present at the direct-voltage terminals of the inverter and/or the output power of the inverter. No current is generated during time intervals with a poor efficiency.

Abstract: A novel voltage regulator includes an indictor, a switching transistor, a rectifier, an error amplifier circuit, a first voltage comparator circuit, a second voltage comparator circuit, an oscillator circuit, and a driver circuit. The first voltage comparator circuit outputs a modulation signal. The second voltage comparator circuit activates an enable signal when the error voltage exceeds the second reference voltage. The oscillator circuit outputs a clock signal with a fixed frequency according to the enable signal. The oscillator circuit enters a first state when the enable signal is activated and deactivated within a period of time shorter than a threshold time, and enters a second state when the enable signal remains activated during a period of time longer than the threshold time. The driver circuit generates the switching control signal based on the clock signal and the modulation signal.

Abstract: A system including is plurality of resistors, a plurality of comparators, and a decoder module. The resistors are connected in series between a supply voltage and a common voltage. A first input of each comparator is connected to a reference voltage. A second input of each comparator is respectively connected to one of a plurality of nodes between the resistors. The decoder module is configured to receive an output from each comparator and to output a plurality of bits based on the output of each comparator. Each of the plurality of bits indicates a different one of a plurality of voltage ranges. A present value of the supply voltage lies in one of the plurality of voltage ranges.