An implementation of zero-voltage transition(ZVT) semi bridgeless boost power factor correction(PFC) converter with quasi-zero-current switching(ZCS) auxiliary switch was proposed. By using an active snubber circuit, the proposed converter provides zero-voltage switching(ZVS) for the main switches and switching naturally for the boost diodes without increasing the voltage stress of them. At the same time, it also further reduces the power loss of the auxiliary switch, and realizes switching naturally for th...