Patent ID: 8076866

Claim:
A ballast for powering a light source, said ballast comprising: a waveform generator for providing a reference waveform signal indicative of a reference waveform having a period; a current sensor for providing a current signal indicative of a current through the light source; a controller for receiving the reference waveform signal and for receiving the current signal, said controller generating an output level signal indicative of an output level wherein the output level is a function of the received reference waveform signal and the received current signal and wherein the controller provides the output level signal at least twice within each period of the reference waveform; and an amplifier for receiving the output level signal from the controller, said amplifier for applying varying power to the light source as a function of the received output level signal wherein the amplifier is responsive to the output level signal to vary the power to the light source at least twice within each period of the reference waveform.