Patent ID: 8049430

Claim:
A multi-switch power converter for an electronic ballast, the power converter comprising: a main transformer having a primary winding for producing an oscillating output voltage; first and second semiconductor switches electrically coupled to the primary winding of the main transformer for conducting current through the primary winding on an alternate basis; a bus capacitor for producing a substantially DC bus voltage, the bus capacitor coupled to the main transformer, such that the DC bus voltage is provided to a center tap of the primary winding of the main transformer; and a first drive circuit operable to control the first semiconductor switch on a cycle-by-cycle basis in response to a first control signal derived from the main transformer and a second control signal received from an external control circuit; wherein the first and second semiconductor switches are coupled between the terminal ends of the primary winding of the main transformer and a circuit common, such that the DC bus voltage is provided across one half of the primary winding of the main transformer when one of the first and second semiconductor switches is conductive.