Dimming control and characteristics of high-frequency operated metal halide lamps

Dimming control and characteristics of high-frequency operated metal-halide (MH) lamps are described. Lamp performance based on two ballast topologies is compared. The dimming range and stability control of the MH lamps are addressed. Dimming range from 100% to about 30% has been achieved. It is found that the combination of ballast topology and dimming method can affect the dimming performance.