Patent ID: 7173380

Claim:
A push-pull inverter comprising: a transformer with three primary windings and a secondary winding, wherein the first and the second primary windings are configured to deliver power in alternating polarities to a load coupled across the secondary winding while the third primary winding is configured to be short-circuited when power is not delivered to the load; a first semiconductor switch coupled between a first terminal of the first primary winding and a reference node, wherein a second terminal of the first primary winding is coupled to a power supply and power is delivered in a first polarity to the load when the first semiconductor switch is active; a second semiconductor switch coupled between a second terminal of the second primary winding and a reference node, wherein a first terminal of the second primary winding is coupled to the power supply and power is delivered in a second polarity to the load when the second semiconductor switch is active; and a third semiconductor switch and a fourth semiconductor switch respectively coupled between opposite terminals of the third primary winding and a common voltage, wherein the third semiconductor switch and the fourth semiconductor switch are active when the first semiconductor switch and the second semiconductor switch are both inactive.