SINGLE-ENDED SOFT-SWITCHING ELECTRONIC BALLAST WITH UNITY POWER-FACTOR

A soft-switching single-ended ac/ac converter that is suitable for hig h-frequency electronic lamp ballast is described. In spite of its simp licity, the converter offers excellent performance with regard to load and supply, ensuring the following: High-frequency supply to the lamp sinusoidal and in-phase supply current easy control of lamp power hig h efficiency due to soft switching at both turnon and turnoff. Steady- state operation, control characteristics, and design criteria are disc ussed, and experimental results are reported, with input and output ci rcuit performance, component stress, and efficiency.