An electronic ballast with wide dimming range, high PF, and low EMI

The authors describe an electronic ballast design with the capability of lo w radiated and conducted EMI over a wide dimming range, It overcomes some l imitations of traditional electronic ballasts that use frequency variation for dimming control, The proposed design allows soft switching of the balla st from full-power operation down to less than 10% power. Low-cost and low- voltage power metal oxide semiconductor held effect transmitters (MOS-FETs) can be used in the proposed dimmable electronic ballast. The design approa ch is described and implemented successfully in a 2 x 36 W fluorescent lamp system.