A power device such as a forward converter employing a main switch in series with a power transformer coupling an input, primary circuit and an output, secondary circuit has its transformer reset from a reset capacitor that is switched. Switching of the reset capacitor is effected by a reset switch, preferably a MOSFET, the control electrode of which is driven from a reset winding on the power transformer. Current flow between the reset capacitor and the primary winding resets the transformer. The capacitor can be chosen such that flux density in the transformer core is substantially symmetrical about zero. Leakage and magnetizing conductance energy is recycled. Large spikes are not produced across the main switch.