A single switch high power factor battery charger

This paper presents a single phase high power factor battery charger using a Cuk converter. The striking feature of this circuit is that it contains only a single switch together with the additional advantage of output isolation as well as voltage step up and step down facility. The buck and boost feature of the Cuk converter is used here for instantaneous input current control along with output voltage regulation. As a result, near-sinusoidal input current is obtained at constant switching frequency. Since the switching frequency used here is high, the response of the converter is fast. A high frequency ferrite transformer is used here to step down the output voltage to charge a 12-volt battery. The experimental result confirms the usefulness of the rectifier-battery charger presented here.