The metal halide lamp is filled with a small amount of metal halides and gases, and it takes more than one minute from triggering to normal illumination, which is roughly divided into three stages.
1. Trigger phase: There is no filament in the metal halide lamp, only two electrodes, directly plus the working voltage can not ignite, must first add high pressure to ionize the gas inside the lamp. The high voltage is generated by a dedicated trigger. 2. Fire stage: After the lamp is triggered, the discharge voltage of the electrode further heats the electrode to form a glow discharge and creates conditions for arc discharge.
3. Normal illuminating stage: Under the action of glow discharge, the electrode temperature is getting higher and higher, the number of electrons emitted is more and more, and the transition to arc discharge is rapid. As the temperature rises further, the light of the lamp becomes stronger and stronger until it is normal, and the whole process takes more than one minute. If the starting current is large, the power starting performance is good, and the process can be shorter.