An improved arrangement of the lamps in the half-bridge topology

This paper presents an alternative high power factor electronic ballast to supply two fluorescent lamps. A modified valley-fill filter provides power factor correction, which is efficient and cheap. A new arrangement of the lamps in the half bridge topology is done, putting one lamp in each switch of the converter. An analysis between typical ballasts and the new one is done. The advantages of this ballast are: if one lamp is damaged, the other keeps working; there is an efficiency improvement when compared to the ballasts that supply only one lamp; and the voltage supported by the switches is half that when compared to the conventional ballasts that supply two lamps.