High efficiency, high frequency power supplies for capacitor and battery charging

A power supply incorporating a simple series-parallel load-resonant converter, capable of efficiently charging both capacitors and batteries is presented. The converter can operate with either constant output current or constant output voltage with minimal control. The frequency of operation of the converter is maintained at 82 kHz. Practical results of the converter charging a capacitor bank to 60 V with constant current and operating with constant output voltage across a variable load are presented. A very simple circuit with inherent constant current or constant voltage characteristics is shown to be a cost effective solution to battery and capacitor charging applications