Single stage soft switching ac/dc converter without any extra switch

This study presents a single-stage single-switch soft-switching converter based on boost-flyback power factor correction (PFC) scheme. In the proposed circuit, soft-switching condition is achieved by only an auxiliary winding on the transformer and a resonant capacitor without any extra switch. The converter operating modes are discussed in details. The design guidelines for the proposed PFC converter, are provided and simulation results are presented. A prototype of this converter is realised to justify the validity of theoretical analysis.