A low cost high power factor electronic ballast

This paper presents a low cost high power factor electronic ballast designed to drive two series connected fluorescent lamps. Low cost is achieved by using a single power processing stage based on a self-oscillating technique. A boost converter operating at discontinuous conduction mode naturally provides high power factor to the utility line. An LC parallel resonant converter yields a high frequency unmodulated sine wave current to drive the fluorescent lamps. This electronic ballast operates above the resonant frequency to perform zero voltage switching, which increases the efficiency. Experimental results have been obtained for two series connected 40 W fluorescent lamps operating at 40 kHz switching frequency from 127 V +/-10%, 60 Hz utility line. The results confirm that the proposed electronic ballast presents high power factor and high efficiency.