A unified dimmable electronic ballast for different light sources

This paper presents a unified dimmable electronic ballast which can drive high-power LED, T8 and electrodeless fluorescent lamps. Basic theory and equations of dimming control for electrodeless, LED and linear lamps are derived. The optimal frequency for dimming T8 and LED lamps varies from 55 kHz to 85 kHz. The electrodeless lamp is from 70 kHz to 90 kHz. A 40W prototype of ballast for electrodeless, LED and T8 lamp is designed and implemented. Experimental results show that the three types of lamps have the same dimming feature with different frequency ranges. They can share the same electronic ballast.