Evaluation of an electronic ballast circuit for HID lamps with passive power factor correction

This paper evaluates a new design of electronic ballast using the standard EN61000-2-3 and the recommended crest factor of the lamp current as references. The solution under study is based on a DC to AC resonant inverter whose input voltage is taken from a valley-fill AC-DC passive converter. The DC output of the valley fill circuit has a ripple of 50%. The output power dependence on the input voltage makes necessary an active compensation technique to stabilise the lamp power. Experimental results prove that the proposed solution is suitable to achieve high efficiency and low cost electronic ballast for low-medium power lamps.