A new dynamic filter for the electronic ballast with the parallel-load resonant inverter

This paper presents an efficient, small-sized, and cost-effective dynamic filter circuit for electronic ballasts with parallel-load resonant inverters. The proposed circuit performs the current shaping function by interposing resonant energy tanks between the bridge rectifier and the inverter stage. Theoretical and experimental results prove that almost unity power factor can be achieved by adding only few reactive components to the original circuit of the electronic ballast