The Study Of Ignition In Metal Halide Lamps

HID(short of High Intensity Discharge lamp),has attracted considerable attention and raised market expectations by its high effect,long life,and good color.Metal halide lamp(MH) is that with the above-mentioned characteristics of an ideal light source.This paper first presents our research work on the starting process of standard Sc-Na system metal halide lamp,and then three aspects which affect the start-up performance in metal halide lamp and get the following conclusion:(1)The ignition in 400w metal halide lamps is the best among all the power types of the metal halide lamps,because its arc tube diameter is in the best length and best fit for the avalanche effect of electronic production.(2) Metal halide lamps which filled with different buffer gases,have different starting voltage.Breakdown and Glow-to-arc transition are the most important two stages during the starting-up.The value of gas breakdown voltage can not represent the performance of ignition is good or bad.Metal halide lamps with different buffer gas should work under different control gear,thus,lamps will give their best light performance.(3)The application of auxiliary electrode can help start up as well as lead to large starting voltages between main electrode and auxiliary in metal halide lamps which result in sputtering of the electrodes and reduced lamp life and light flux.The ignition of metal halide lamps is decided not only by the lamps themselves but also by the control gear,different lamps should run under different control gears in order to achieve the best results.The research of MH start-up can help us design better control gears and design new lamps.However,even though lamps are often considered a mature technology,the discharge physics is often poorly understood,so there is a long distance we should go.