Universal input voltage self-oscillating electronic ballast based on switching frequency control

This work presents a universal input voltage electronic ballast supplying a 32 W T8 fluorescent lamp. The electronic ballast is formed by a self-oscillating command circuit and an additional circuit. The additional circuit is used to guaranty the rated power of the fluorescent lamp through the voltage gain variation of the resonant filter. Thus, the switching frequency changes based on feedforward control to keep the nominal lamp power. Simulation and experimental results of the electronic ballast are presented to demonstrate the feasibility of the proposed system.