Electronic Ballast to Supply HID Lamps Based on Differential Connection of Two DC/DC Converters

The differential connection of two DC/DC converters to supply HID lamps in a low frequency square waveform is presented. This technique becomes possible the integration between the power control and the inverter stage of the electronic ballast. This paper presents some topologies that use the proposed technique, further on an extended analysis of one of them, in order to verify the functionality of the technique. The developed ballast example consists of a bidirectional flyback modulated according to a square waveform modulation law, supplying the lamp in a 150Hz square waveform. An igniter circuit is employed to provide the necessary voltage for lamp start up. The experimental results validate the proposed technique