The Active Clamp Sepic- Flyback Converter

A high efficiency active clamp sepic-flyback converter is presented. The proposed converter is superposition of sepic converter mode and flyback converter mode. Not only sepic mode output but also flyback mode output can be fully regulated by constant frequency PWM control. Merging sepic and flyback topology can share the transformer, power MOSFET, and active clamp circuit. It has outstanding advantages over the conventional dc-dc converters with respect to high efficiency, high power density, and component utilization. The operation principle of the proposed converter is described and verified by simulation and experimental result