High efficiency, low size, and low weight vehicle battery charger

Ferroresonant car battery charger poses a major challenge because of low efficiency and power factor. Also these chargers have very big size and weight. In this paper, a PFC and flyback converters for 84 W AC-DC car battery chargers is design. To reduce the converters switching losses and improve its efficiency, critical conduction mode and valley switching technique are used to control the PFC and DC-DC stages, respectively. Using the proposed configuration, higher efficiency, smaller weight and size, and better output voltage regulation are achieved, as compared to the conventional ferroresonant car battery chargers. Also the proposed structure can operate with universal voltage (90-264 V_ac). Finally, an experimental prototype of this charger was implemented to verify analytical analysis and simulation results. The experimental results are in good agreement with the given simulation results and the analytical calculations.