A constant power battery charger circuit with inherent soft switching and PFC

A battery charger circuit is proposed which operates as a constant power source by means of discontinuous operation of the two half bridge dividing capacitors. Its input characteristic is resistive and input harmonic current content can meet international regulation. Soft switching is also accomplished by paralleling two diodes across two dividing capacitors. A 12 V 65 W prototype was built to demonstrate the merit of this topology.