the path of the capacitor c dc2 u2192 the primary winding n 1 of the transformer tr u2192 the inductor l r u2192 the capacitor c r u2192 the switching device q 2 u2192 the capacitor c dc2 thus the current i r1 flowing in the primary winding n 1 of the transformer tr becomes a current which is provided as a combination of the currents i c1 and i c2 their respective current values are also designated as i c1 and i c2 to have a value i c1 i c2 as is shown in fig2 moreover the voltage v tr2 and current i r2 of the secondary winding n 2 of the transformer tr become in phase with the voltage v tr1 and current i r1 of the primary winding n 1 respectively the current i r2 is subjected to full wave rectification in the rectifier circuit rec to be a dc output current i o then the dc output current i o is supplied to a load r from both ends of which a dc output voltage e o which is smoothed by the smoothing capacitor c o is outputted with a specified magnitude by the foregoing operation zero current switching.