This paper presents a self-oscillating electronic ballast employing a modified valley-fill filter in order to meet IEC 61000-3-2 Class C requirements. In order to overcome the drawback of high fluorescent lamp current crest factor, which is inherent to the valley fill filter, it is employed a frequency modulation system that keeps the crest factor lower than 1.7 limit using a simple and low cost circuit. This system uses the resonant filter features added to the possibility to control self-oscillating frequency using electronic ballast bus voltage feature. Simulation and experimental results are presented to demonstrate the system performance.
electronic ballast; power electronics; power-factor; fluorescent lamp; self-oscillating; valley-fill filter; fluorescent lamp
