Analysis and design of a flyback zero-current switched quasiresonant AC/DC converter

A flyback zero-current switched (ZCS) quasiresonant AC/DC converter, functioning as a power factor correction regulator, is presented and analysed in detail. Only one active switch with simple control logic is required to achieve both input current waveshaping and output voltage regulation. The investigation of voltage and current waveforms of the proposed converter is followed by simulation and leads to a design example to verify the theoretical results. An experimental unit of 120 W was built which confirmed the analysis and simulated results