A novel single-stage half-bridge AC-DC converter with high power factor

A new single-stage ac-dc converter based on a half-bridge converter suitabl e for low-power applications is proposed. The proposed converter offers hig h power factor and direct conversion from the line voltage to an isolated d c output voltage. High power factor is achieved by adding a resonant circui t between the rectifying diodes and half-bridge leg. For soft switching, th e half-bridge series-loaded resonant converter is adopted as a dc-dc conver ter part. A prototype is built and tested to show the validity of the propo sed converter.