Single Stage Self-Oscillating HPF Electronic Ballast

This paper presents a single-stage self-oscillating high-power-factor electronic ballast more suitable for both low power levels (because it operates in discontinuous conduction mode) and low ac mains applications (since it employs an input-doubler rectifier). The electronic ballast is based on a high-frequency dither signal, which shapes the input current in a sinusoidal waveform. In order to reduce the electronic ballast components the self-oscillation technique has been employed. An electronic ballast prototype operating at 25 kHz has been implemented to drive two 40-W straight-type fluorescent lamps from a 127-V utility line. High power factor is achieved even though the electronic ballast drives just one fluorescent lamp. The experimental results demonstrated the electronic ballast operation.