Patent ID: 6819057
Filing Date: 2004-11-16
Classification: H02M,H05B,Y02B

Abstract:
A self-oscillating ballast inverter circuit for a discharge lamp comprising:at least one input terminal adapted for connection to a DC voltage source; at least one switch connected across the DC voltage source; a resonant load connected to the at least one switch; a lamp connector connected to the resonant load; a feedback transformer having a primary winding, the feedback transformer having a secondary winding corresponding to each said at least one switch, each said secondary winding being connected to a control terminal of a respective said at least one switch; and a start phase shifter circuit connected between the resonant load circuit and the primary winding of the feedback transformer, a first branch of the start phase shifter circuit being connected between the resonant load and a first terminal of the primary winding, a second branch of the start phase shifter circuit being connected between a node of the first branch and a second terminal of the primary winding.