Patent ID: 8742670
Filing Date: 2014-06-03
Classification: H05B

Abstract:
1. An electronic ballast for driving at least one light emitting element, comprising: a square-wave generator that comprises a plurality of switching elements which turn on alternately to convert a direct current input voltage to an alternating current square wave of output voltage; a transformer that comprises a driving winding, a plurality of control windings and at least one inductive winding, wherein the driving winding, the control windings and the inductive winding are coupled with each other, and the plurality of control windings are electrically connected with control terminals of the plurality of switching elements respectively so as to control the plurality of switching elements to turn on alternately; a resonant circuit that constitutes a resonant loop together with the driving winding, is electrically connected with an output terminal of the square wave generator and drives the light emitting element; and at least one control driving circuit that is connected with two terminals of the inductive winding in parallel and receives a control signal to control a voltage across the inductive winding so as to control conducting time of at least one of the switching elements.