Digital-dimming controller with primary-side regulation technique for EFL electronic ballast

A MCU-based electronic ballast for electrodeless fluorescent lamp (EFL) is implemented in this paper. The main circuit consists of a class D converter and a resonant circuit to form a resonant inverter. In addition, an 8-bit microcontroller is employed to act as the control core of the system to achieve soft start and smooth dimming feature. Moreover, we not only discuss the lamp model, the related control methods, but also implement the lamp current regulation by using the primary-side control to stabilize the preset lamp current. Finally, the experimental results are used to verify the feasibility and validity of the proposed system.