Low loss snubber circuit with active recovery switch

Claim 1

A switchmode power converter including a circuit for achieving low loss snubbing across the switching element comprising: a transformer with at least two windings and the primary of which transformer has a switching element side and a line side; a switching element in series with the primary winding, said switching element having a transformer side of the switching element and a line side of the switching element; a snubber diode and a snubber capacitor in series with one another across the switching element; a discharge path for discharging the capacitor including a second diode, a switch and an inductor, said discharge path extending from the node between the snubber diode and the snubber capacitor to the line side of the primary of the transformer; a winding coupled to the inductor, said winding being in series with a third diode and said winding and third diode in series extending between the line side of the switching element and the line side of the transformer; and a third winding of the transformer in series with the discharge path.