Multi-rating electronic ballast for fluorescent lamp using phase-locked loop control scheme

This paper proposes a multi-rating electronics ballast for fluorescent lamp using phase-locked loop control scheme. By this method, the resonant frequency of the circuit is continuously tracked. Compared with the previous Phase-locked loop (PLL) control of the electronic ballasts for fluorescent lamps, the proposed method can have resonant frequency tracked for the electronic ballasts, where the equivalent resistance of the fluorescent lamps is changed. With the lamp power regulator, the proposed PLL controller commands the DC voltage to the boost converter to lock the resonant frequency. The implementation of a circuit is provided to evaluate the performance of the proposed PLL control scheme.