Patent ID: 7352136

Claim:
A DC-DC converter for providing an output DC voltage to a load, said converter comprising: a transformer having a primary winding and a secondary winding; a switching element connected in series with said primary winding across a DC voltage source, said switching element being driven to turn on and off for repetitively interrupting a current flowing through said primary winding to induce a voltage across said secondary winding; a rectifier diode connected in series with said secondary winding across said load to apply said induced voltage to said load as an output DC voltage which is negative with respect to a circuit ground; a snubber capacitor connected in series with a snubber diode across said switching element to be charged by current flowing through said primary winding when said switching element is off; a storage capacitor connected in series with a reactor across said switching element in parallel with said snubber diode to be charged by a current from said snubber capacitor through said reactor when said switching element is on and off, a replenishing diode connected in series with said load across said storage capacitor to allow said storage capacitor to discharge for providing an additional power to said load.