Abstract: A power supply apparatus includes a power supply circuit and an active clamping circuit. The power supply circuit includes a secondary side rectifying unit and a voltage output side. The active clamping circuit includes a clamping energy-storing unit, a feedback control unit and a synchronous buck converter. The clamping energy-storing unit clamps and stores a voltage spike to obtain an energy-storing voltage. The feedback control unit detects the energy-storing voltage and informs the synchronous buck converter of the energy-storing voltage. The synchronous buck converter receives the energy-storing voltage and adjusts the energy-storing voltage to obtain an adjusted voltage when the energy-storing voltage is greater than a predetermined voltage. The synchronous buck converter sends the adjusted voltage to the voltage output side.

Abstract: A power supply apparatus includes a power supply circuit and an active clamping circuit. The power supply circuit includes a secondary side rectifying unit and a voltage output side. The active clamping circuit includes a clamping energy-storing unit, a feedback control unit and a synchronous buck converter. The clamping energy-storing unit clamps and stores a voltage spike to obtain an energy-storing voltage. The feedback control unit detects the energy-storing voltage and informs the synchronous buck converter of the energy-storing voltage. The synchronous buck converter receives the energy-storing voltage and adjusts the energy-storing voltage to obtain an adjusted voltage when the energy-storing voltage is greater than a predetermined voltage. The synchronous buck converter sends the adjusted voltage to the voltage output side.

Abstract: An inductive element and corresponding method for making an inductive element for surface mounting on an adjacent structure for providing improved heat transfer characteristics. Specifically, a core and winding of the inductive element define coplanar surfaces that can then be mated to an adjacent structure, preferably a printed circuit board. Devices such as inductors or transformers including the inductive element have multiple, low thermal resistance conductive paths for removing heat from the core, and thereby enhance the heat transfer characteristics of the devices. The inductive element is particularly well suited for power electronics, such as for use as a power choke or as part of a power transformer.

Abstract: A current sharing circuit has a plurality of power devices, such as diode rectifiers, connected in a parallel arrangement. Each leg of the parallel arrangement comprises one power device connected in series to an inductive element. The series resistance of the inductive element in each leg of the parallel circuit moderates the affect of temperature variations on the current drawn by each power device, which enables substantially equal current sharing to occur. As used in switch mode power supplies, such as forward converters and boost converters, the current sharing circuit provides the benefit of substantially equal current sharing between power devices without increasing resistive losses which would reduce the efficiency of the power supply.