Low Cost High Power Factor Electronic Ballast with No Input Filter

A new topology of electronic ballast for fluorescent lamps employing the charge pump concept but with no LC input filter is presented in this paper. The use of magnetic coupled boost inductors together with the connection of the resonant capacitor directly at the input stage assures high power factor even with no filtering stage for the input current. Thereby, the proposed electronic ballast presents high input power factor and arises as an interesting solution for large scale production since the component count is reduced. With the operating principle and the mathematical analysis developed the unity power factor condition is obtained easily. Proving the results of the design methodology, experimental results coming from a prototype with fixed switching frequency and also with self oscillating drive technique are presented in a 2times40 W electronic ballast