METHOD TO ENSURE BALLAST STARTING REGARDLESS OF HALF CYCLE INPUT

摘要

A ballast circuit (6) comprises a rectifier circuit (8) and dual starting circuits (11, 13) that ensure ballast startup and lamp ignition regardless of input waveform half cycle. The first starting circuit comprises resonant circuit (10), and the second starting circuit includes a resistor (11). The resistor (11) comprising the second startup circuit provides a bias resistance to the second switches (72) to ensure ballast startup when an oscillating input waveform is in a negative phase.