Design and implementation of novel single-stage charge-pump power-factor-correction electronic ballast for metal halide lamp

This paper presents a novel single-stage charge-pump (CP) power-factor-correction (PFC) electronic ballast for metal halide (MH) lamps driven with the low-frequency square-wave current to avoid the acoustic-resonance problem. In order to achieve high power factor (PF) and meet the International Electrotechnical Commission (IEC) regulation, the CP PFC technique is applied to the full-bridge inverter of the conventional electronic ballast. Based on the analyses of the operational modes for the proposed electronic ballast, the design criteria of the CP components and the main inductor in the full-bridge inverter for the proposed electronic ballast are presented. A prototype circuit for a 35-W MH lamp is implemented to confirm the presented design criteria.