High efficiency DC-DC power converter with turn-off snubber

Abstract

The invention is a DC-DC converter in which the voltage across the main switch due to the leakage inductance of the transformer is clamped and a pair of capacitors play the role of lossless turn-off snubbers to recycle the leakage energy of the transformer instead of dissipating the energy so as to improve the circuit efficiency. The DC-DC converter has a voltage source which is connected to a switch. A transformer first primary winding is in series with a first capacitor. This winding and capacitor are connected across the voltage source and switch. A transformer second primary winding is in series with a second capacitor. They are also connected across the voltage source and switch. The transformer first and second primary windings have first and second leakage inductances respectively. A first diode has one terminal connected to terminals of the transformer first primary winding and the first capacitor. The first diode also has a second terminal connected to the terminals of the transformer second primary winding and the second capacitor. The first diode and first capacitor form a first snubber circuit, while the first diode and second capacitor form a second snubber circuit. The first and transformer second primary windings providing energy to a transformer secondary winding. In so doing the voltage across the main switch due to the leakage inductance of the transformer is clamped and the leakage energy of the transformer is recovered by charging the first and second capacitors and the delivered output by the magnetizing inductance instead of being dissipated by the first and second snubber circuits. The first and second snubber circuits are lossless and therefore circuit efficiency is improved.

Dependencies are inferred from the claim text.