Halogen lamp

Car Headlights

    Car Headlights (halogen lamp) are a special incandescent lamp. The principle is that heat will be released when an electric current passes through a resistant, and when the temperature is sufficiently high the wavelength of the black body radiation is within the visible light spectrum.

    There are two kinds of halogen lamps: iodine tungsten lamp and bromine tungsten lamp, which share the same principle. When the incandescent lamp is lit, although the temperature of the filament is lower than the melting and boiling point of tungsten, small amount of tungsten will still be vaporized at this high temperature. When the volatile tungsten atoms collide with the cooler bulb shell, they coagulate to from precipitate, and as time passes a black layer of tungsten accumulates on the bulb shell. For this reason the shell of a normal incandescent lamp turns dark after used by a long period. If iodine is injected into the light bulb, when it is lit, iodine will vaporized as gas, iodine vapor collide with the cooler bulb shell, react with it, resulting a compound with low boiling point – tungsten iodide, thus causes the tungsten film on the bulb to vaporize. Tungsten iodide gas decomposes at high temperature. When tungsten iodide collide with the tungsten filament, it decomposes, leaving tungsten on the filament, while iodine dissociates as gaseous state between the bulb shell and filament, when it collide with the bulb shell again, it reacts with the tungsten on the bulb shell…… So, the filament is continuously vaporizing tungsten onto the bulb shell, on the other hand iodine is continuously carrying tungsten back to the filament, in this way the consumption of the filament is significantly lowered, life of the light bulb can be extended. Therefore, iodine tungsten lamp can be used to manufacture a high efficiency incandescent lamp, for example 1000W. Without halogen, a normal incandescent lamp with such a high efficiency will have a much shorter life time, which is impractical.

    Halogen lamps are wildly used in the field of car illuminating system.

    Wholesale Car Headlights,sell only the high quality Auto Headlights in low price and qualified service. If you need Auto Headlights, please browse www.ucarshop.com for samples.