Electronic ballast for fluorescent lamps without light fluctuation

In attempting to eliminate light fluctuation, an electronic ballast is proposed to drive fluorescent lamps with DC current. The ballast makes use of a high-frequency half-bridge resonant inverter to generate a high ignition voltage and an AC ballasting current, which is then converted into a DC current by a rectifier. To avoid the damage of cathode filaments, a full-bridge inverter is used for commutation of the electrodes. A prototype is designed and built for the OSRAM T5-80 W fluorescent lamp. In addition to eliminating light fluctuation, experimental results show that the electronic ballast has a high-power-factor and dimming capability.