1MHz Class D Electronic Ballast for Metal Halide Lamp 250 Watt

This paper presented a 1MHz electronic ballast for metal halide lamp (HPI/T 250W, Philips), which avoids the problem of acoustic resonance. The ballast is base on the class D series-parallel resonant inverter and its operated by very high frequency from class E resonant inverter. The ballast don't need an ignitor for starting the lamp. Because the class D inverter can build high voltage by LCC resonant circuit and reduce starting voltage after starting the lamp automatically. Technical data for designing the class D inverter and the class E inverter are described. The experimental results from a prototype electronic ballast has good performances as ZVS switch, high efficiency (82.3%).