Abstract: A method for improving a power converter's efficiency comprises providing a resonant converter, wherein the resonant converter comprises an input coupled to a power source, a plurality of power switches coupled to the input, a resonant tank coupled to the plurality of power switches and a controller coupled to the power switches and generating a plurality of gate drive signals for the power switches, wherein the gate drive signals are arranged such that a switching frequency of the resonant converter is in a frequency band.

Abstract: An apparatus comprises a bridge coupled between a bias voltage and ground, wherein the bridge comprises a first switch and a second switch connected in series and coupled between the bias voltage and ground and a third switch and a fourth switch connected in series and coupled between the bias voltage and ground, a resonant device coupled to the bridge, wherein the resonant device comprises a fixed capacitance, a gate capacitance and a magnetizing inductance, a transformer coupled to the resonant device, wherein the transformer comprises a primary winding and a plurality of secondary windings.

Abstract: An apparatus comprises a magnetic device coupled to an inductor-inductor-capacitor (LLC) resonant converter, an ac current sensing circuit coupled to the magnetic device, an average current sensing circuit coupled to the ac current sensing circuit and a reference voltage source coupled to the average current sensing circuit, wherein the reference voltage source is configured such that a magnitude of an average signal from the average current sensing circuit is greater than a voltage level of the reference voltage source.

Abstract: An apparatus comprises a first series resonant inductor coupled to a switching network and a transformer, a first series resonant capacitor coupled to the switching network and the transformer, a first parallel inductor coupled to the switching network through the first series resonant inductor and the first series resonant capacitor, a resonant frequency adjusting device coupled to the switching network and the transformer and a switch connected in series with the resonant frequency adjusting device.

Abstract: A method comprises providing a resonant converter, wherein the resonant converter comprises an input switch network coupled to a power source, wherein the input switch network comprises a plurality of power switches, a resonant tank coupled to the plurality of power switches, a transformer coupled to the resonant tank and an output stage coupled to the transformer, wherein the output stage comprises a synchronous rectifier formed by a first switch and a second switch, detecting a drain voltage of the first switch, comparing the drain voltage with a predetermined voltage threshold, wherein the drain voltage is coupled to a negative input of a comparator and the predetermined voltage threshold is coupled to a positive input of the comparator, generating a logic state based upon an output of the comparator and adjusting, by a control circuit, a switching frequency of the resonant converter based upon the logic state.

Abstract: A method comprises providing a resonant converter comprising a switching network comprising a plurality of switches, a resonant tank coupled between the switching network and a transformer, wherein the resonant tank comprises a series resonant inductor coupled to a switching network and the transformer and a series resonant capacitor coupled to the switching network and the transformer and a driver having an adjustable bias voltage and in response to a startup process of the resonant converter, configuring the switching network to operate a switching frequency higher than a resonant frequency of the resonant tank.

Abstract: A converter comprises an input stage coupled to a power source, wherein the input stage comprises a plurality of power switches, a resonant tank coupled to the plurality of power switches, a transformer coupled to the resonant tank, an output stage coupled to the transformer, an efficiency point tracking indicator coupled to the converter, a detector coupled to the efficiency point tracking indicator and a control circuit configured to receive an efficiency point tracking signal from the detector and adjust a switching frequency of the power switches based upon the efficiency point tracking signal.

Abstract: A converter comprises an input stage coupled to a power source, wherein the input stage comprises a plurality of power switches, a first resonant tank coupled to the input stage, wherein the first resonant tank is of a first Q value, a second resonant tank coupled to the input stage, wherein the second resonant tank is of a second Q value, a transformer coupled to the input stage through the first resonant tank and the second resonant tank and an output stage coupled to the transformer.

Abstract: A method for improving a power converter's efficiency comprises detecting an input voltage of a power converter, determining an operation mode of the power converter based upon the input voltage of the power converter and generating a plurality of gate drive signals based upon a damped gain control, wherein the damped gain control is configured such that an output voltage of the power converter is in a range from a tightly regulated output voltage to an unregulated output voltage.

Abstract: A method for improving a power converter's efficiency comprises providing a resonant converter, wherein the resonant converter comprises an input coupled to a power source, a plurality of power switches coupled to the input, a resonant tank coupled to the plurality of power switches and a controller coupled to the power switches and generating a plurality of gate drive signals for the power switches, wherein the gate drive signals are arranged such that a switching frequency of the resonant converter is in a frequency band.

Abstract: A solar light power generation system, a control device, and a control method thereof are provided. The solar light power generation system includes: a solar cell array configured to output a plurality of branches of electric energy; a combination control unit configured to receive the plurality of branches of electric energy output by the solar cell array, detect output characteristics of the plurality of branches of electric energy, and adjust combination of series connection and/or parallel connection of the plurality of branches of electric energy dynamically according to the output characteristics, so as to output one or more branches of electric energy; and an energy converting unit, configured to receive the one or more branches of electric energy output by the combination control unit, perform energy converting, and output the converted electric energy. The system adjusts combination of the branches of electric energy.

Abstract: The present invention is directed to a transient suppressor, a method of suppressing a peak voltage associated with a rectifier, and a power converter employing the same. In one embodiment, the transient suppressor includes a saturable reactor circuit interposed between a rectifier and a transformer winding. The transient suppressor also includes a RC circuit, coupled between the rectifier and the saturable reactor circuit and across the transformer winding, configured to cooperate with the saturable reactor circuit to suppress a peak voltage associated with the rectifier.

Abstract: A transformer assembly and method for powering a load with a secondary fault protected isolated secondary. The fault fault path is isolated from ground allowing voltage detection of faults and the return terminal is isolated from the midpoint for multiple load connection schemes using the midpoint as a ground connection. A power control system is connected between the primary winding and the input terminal with a ground fault detection circuit connected between the fault path and the ground terminal, where the ground fault detection circuit is operable to detect a fault and activate the power control system to disconnect the source of power from the primary winding in response to detecting the fault. Also disclosed is a high frequency filter adapted to reduce the effects of high frequency transients and a capacitive reactance connected between the input terminal means and the ground terminal. The capacitive reactance is adapted to provide a ground fault path for fault signals.

Abstract: An electronic ballast apparatus for powering one or more gas discharge lamps includes an inverter that is controlled by an inverter control circuit. The inverter control circuit adjusts certain ballast operating characteristics in order to operate the lamps under nearly the same operating conditions irrespective of how many lamps are connected to the ballast. The inverter control circuit includes a lamp quantity sensor, a regulator circuit and an end-of-lamp-life sensor. The lamp quantity sensor provides a lamp quantity signal that indicates how many lamps are connected to the ballast. The regulator circuit includes a reference adjustment circuit that receives the lamp quantity signal and provides a scaled reference signal to a reference terminal of an error amplifier. The error amplifier also has a feedback terminal that receives a signal that is proportional to the power delivered by the inverter to the lamps.

Abstract: A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.