Patent ID: 7132803
Filing Date: 2006-11-07
Classification: H05B,Y02B

Abstract:
1. An electronic ballast for igniting and driving at least two gas discharge lamps, comprising: a pair of power input terminals for receiving a power supply voltage; a single inverter circuit for receiving said power supply voltage and producing an AC output voltage; two resonant output circuits wherein each resonant output circuit receives the output AC voltage from the single inverter circuit and provides a drive voltage to a pair of gas discharge lamp terminals associated with the resonant output circuit and wherein each resonant output circuit includes a capacitor; and a microprocessor circuit connected to the inverter circuit and the two resonant output circuits for monitoring a voltage across the capacitor in each of the resonant output circuits and for generating inverter control signals that cause the inverter circuit to attempt to ignite lamps connected to the resonant output circuits only when the voltages across the capacitors indicate that lamps are connected to the resonant output circuits.