A dimmable electronic ballast for CFLs compatible with phase-cut dimmers

In this paper a new dimmable electronic ballast circuit compatible with available commercial phase-cut dimmers for compact fluorescent lamps (CFLs) is proposed. Proposed circuit has considerably low cost and controls the output light linearly with high power factor (PF) in the whole dimming firing angles. In the proposed dimming circuit, desired firing angle convert into power switch duty cycle with a linear relation. Power switch duty cycle controls the DC-Link voltage and the output power is determined by this voltage. In this paper operation of the proposed dimming circuit along with duty cycle variation following firing angle variations has been explained. To explore the feasibility of proposed circuit, a 42 Watts CFL was tested under a laboratory prototype of proposed circuit.