A new proposal of switched power oscillator with soft-commutation applied as a HPF electronic ballast

A new switched power oscillator with reduced conduction losses, zero voltage and zero current turning on, and zero voltage turning off, is presented in this paper. The proposed topology consists on a buck plus boost converter operating in continuous conduction mode (CCM) associated to a self-oscillating LC series resonant circuit. This new power oscillator can be applied as an electronic ballast for fluorescent lamps as well as self-oscillating auxiliary medium open loop power supply. Circuit description and experimental results of the proposed HPF electronic ballast with low THD_I (7.3%), high PP (99.73%), and crest factor equal to 1.4 are presented. A high power factor electronic ballast prototype switching at 40 kHz for a 40 W fluorescent lamp has been built and analyzed experimentally and by simulation.