The light-emitting principle of all incandescent lamps is realized by using the principle of heating and radiating the object. The simplest incandescent lamp is to conduct enough current to the filament, and the filament will emit light when it heats up to the incandescent state, but this kind of incandescence The lamp life will be quite short.
The biggest difference between halogen bulbs and other incandescent lamps is that the glass shell of the halogen lamp is filled with some halogen gas (usually iodine or bromine), and its working principle is: when the filament heats up, the tungsten atoms are evaporated backwards The glass tube wall moves in the direction. When it approaches the glass tube wall, the tungsten vapor is cooled to about 800°C and combines with halogen atoms to form tungsten halide (tungsten iodide or tungsten bromide). The tungsten halide continues to move to the center of the glass tube, and then returns to the oxidized filament. Because tungsten halide is a very unstable compound, it will decompose into halogen vapor and tungsten again when heated, so that tungsten is in the filament again. Deposited on top to make up for the evaporated part. Through this regeneration cycle process, the service life of the filament is not only greatly extended (almost 4 times that of incandescent lamps), but also because the filament can work at a higher temperature, higher brightness, higher color temperature and Higher luminous efficiency.