Asymmetrical half-bridge in a single stage PFC AC/DC converter

Single-stage PFC AC/DC power converters promise lower cost and simplicity than two-stage converters. This is especially important for low power converters. A new family of single-stage PFC converters is proposed where an asymmetrical half-bridge DC/DC converter (AHBC) is utilized as a DC/DC cell. AHBC topology allows for a ZVS condition in its complementary driven switches. Retaining this property in the proposed AC/DC converter substantially enhances its efficiency. The circuits exhibit extreme simplicity while providing well-regulated output with low ripple and good power factor