A low-cost high power factor resonant mode battery charger

A power converter for battery charger applications, which has at the input a full wave rectifier, followed by a series resonant power converter with a clamped voltage resonant capacitor, is presented. In this converter, only two MOSFETs are employed. They control the current delivered to the battery across a high-frequency isolation transformer, and produce a high (near unity) power factor input current. The proposed topology allows the design of low cost equipment. A laboratory prototype has been built, rated at 440 W and 48 V, with measured efficiency of 0.89 and power factor of 0.96 full load.<
>