Patent ID: 7589476
Filing Date: 2009-09-15
Classification: H05B,Y10S

Abstract:
1. A power supply circuit for providing power for a plurality of external electrode fluorescent lamps (EEFLs) connected in parallel, comprising: a controllable voltage regulator for receiving an input power signal and for providing a regulated voltage signal; an output inverter and a resonant circuit connected to receive the regulated voltage signal and for providing a resonant frequency signal; a voltage transformation stage for receiving the resonant frequency signal for transforming the resonant frequency signal to a power voltage signal capable of driving a plurality of EEFLs connected in parallel; wherein the controllable voltage regulator is connected to receive the resonant frequency signal and is responsive thereto to keep the resonant frequency signal within an acceptable operating voltage range to power the EEFLs independently of the number of EEFLs connected to receive the power voltage signal.