Why do metal halide lamps develop pulse-starting technology? What is the principle of pulse-starting metal halides? What are the advantages? The answer    linsheng    announced

　　Conventional metal halide bulbs use a probe activation technique that uses three electrodes - a starter electrode and two operating electrodes - to activate the bulb in an arc tube. When the bulb is first turned on, a discharge is generated on a small gap between the starter probe electrode and the nearby operating electrode. The electron then jumps through the arc tube to another operating electrode to help activate the bulb. Once the lamp is activated, the bimetal switch removes the starter probe electrode from the circuit. Due to the tungsten sputtering of the electrodes and the blackening of the arc tube wall, the probe-initiating metal halide undergoes lumen loss during the life of the bulb.

　　Metal halide bulbs do not immediately begin to produce their full lumen output at startup because the temperature and pressure in the inner arc tube takes time to reach full operating level. It usually takes a few seconds to start the initial arc, and the warm-up time can be as long as five minutes, depending on the type of bulb. During this time, as various metal halides evaporate in the arc chamber, the bulbs exhibit different colors.

　　If the power supply is interrupted, even if it is short-lived, the arc of the bulb will extinguish and the high voltage present in the thermal arc tube will prevent the arc from colliding again. The bulb needs time to cool before restarting the arc. In a typical probe starting metal halide this can be 10 to 20 minutes. The time it takes for the HID bulb to return to its full lumen output after a momentary power interruption is called a warm restart time or a warm restart. This is a problem in some lighting applications where long periods of lighting interruption can result in manufacturing downtime or safety issues. The pulse-start metal halide bulb uses a ballast with a very high operating voltage and has an instant restart capability to restart the heat bulb.

　　The pulse-start metal halide bulb has no starter probe electrode. Instead, they have a high-voltage igniter that, in conjunction with the ballast, uses a series of high-voltage pulses (typically 3 to 5 kV) to start the bulb. The high voltage pulse allows the lamp to warm up and achieve full lumen output and reduce thermal re-arc time faster than the probe activates the bulb; the pulse-start metal halide bulb can be restarted in only 5-7 minutes.

　　In the absence of a probe electrode, the sealing area at the end of the arc tube is reduced, which results in a reduction in heat loss. In addition, the use of an igniter with a bulb reduces tungsten sputtering by heating the electrode faster during startup; therefore, less lumen depreciation due to the tungsten blackened bulb. In addition, since the tungsten has a long residual time on the electrode, the life of the pulse-activated bulb is longer than that of the probe-starting metal halide bulb.

　　Another difference between conventional metal halide bulbs and pulse-start metal halide bulbs is their degree of color shift. The probe activates the bulb with a positive or negative 300K color shift, while the pulse-activated bulb has improved color rendering and a more controllable CCT. The color shift of the pulse-activated bulb is plus or minus 100K, which is still a significant difference, but better than the probe-starting bulb.

　　Pulse start technology was developed to increase lamp life while providing the energy efficiency of a high pressure sodium bulb and the desired color characteristics of a metal halide bulb. The benefits of pulse-activated bulbs include superior efficacy; faster, more reliable start-up - even at cold temperatures; longer life; and increased lumen maintenance

https://www.linsheng.com