Dimming Electronic Ballasts Without Striations

Power density modulation control strategy is proposed for eliminating the striations in dimming applications. In a modulation period, the lamp is operated in several states. For any desired lamp power, the fluorescent lamp current requirement must be met in one of the states. A prototype dimmable electronic ballast is built and experimented. As result, a 36WT8 fluorescent lamp is driven within wide power range from 2 W to full without striation.