Patent ID: 7952303
Filing Date: 2011-05-31
Classification: H05B,Y10S

Abstract:
1. An electronic ballast for a gas discharge lamp having a filament, comprising: a dimming controller having a dimming controller output and operable to generate a dimming controller signal at the dimming controller output, wherein the dimming controller signal has a dimming request range; a full power circuit having a full power output for coupling to the lamp, a power control coupled to the dimming controller output to receive the dimming controller signal, wherein the full power circuit is operable to generate a full power signal at the full power output when the dimming controller signal is not in the dimming request range, and further wherein the full power signal has a magnitude; a reduced power circuit operable to provide a reduced power signal to the lamp when the full power signal is not present, and wherein the reduced power signal has a magnitude less than the magnitude of the full power signal; and a filament heating circuit having a heating input coupled to the reduced power circuit and a heating output for coupling to the filament, wherein the filament heating circuit is operable to generate a filament heating signal, responsive to the reduced power signal, at the heating output when the reduced power signal is present.