Buck-boost push-pull high power factor electronic ballast

This paper proposes a high power factor electronic ballast that supplies two tubular fluorescent lamps. It is formed by two converters operating in a cascade mode. The first one is a buck-boost converter operating in a discontinuous conduction mode and the second one is a push-pull converter that provides the high frequency to the load. Experimental results were obtained for two 40 W fluorescent lamps operating at 50 kHz switching frequency and 110 V/sub RMS/ line voltage.