A novel single-stage low-frequency square-wave electronic ballast for low-wattage HID lamps

A novel single-stage electronic ballast for low-wattage HID lamps is presented in this paper. The ballast is obtained from the integration of a single-stage power factor correction converter and a low-frequency inverter. The output power to the lamps is constant approximately due to the constant power control. This circuit achieves high power factor and acoustic resonance free with simpler and cheaper topology. Some experimental results obtained from a laboratory prototype for a 70 W metal halide lamp verifies its feasibility.