Single stage forward-flyback converter and power supply apparatus

摘要

There is provided a single-stage forward-flyback converter capable of increasing power factor and power conversion efficiency while performing power factor correction and constant current control in a single-stage circuit. The converter includes: a power converting unit including a transformer having a primary winding receiving input power and a secondary winding magnetically coupled to the primary winding to receive power induced thereto, and converting the input power in a forward scheme and a flyback scheme; a balancing unit maintaining balance between a power level by the forward scheme of the power converting unit and a power level by the flyback scheme thereof; and a path providing unit clamping the power by the forward scheme of the power converting unit and the power by the flyback scheme thereof to provide a power transfer path, wherein the power converting unit selectively operates the forward scheme according to a voltage level of input power.