A modified zero voltage switching forward converter topology with self core reset

A self-core-reset zero voltage switching (ZVS) forward converter topology is presented in this paper. In this topology, ZVS in the main switch is achieved with a simple auxiliary circuit and, importantly, the power transformer self resets without the use of the conventional tertiary reset winding. The transformer becomes simplified, and the cost in manufacture is reduced. Analysis of the circuit is presented. The flux swing in such a topology is investigated, and optimal operating point of flux is determined. Experiments on a 5 V, 100 W prototype circuit switched at a frequency of 200 kHz verify the design.