1. halogen
the same basic emission principle halogen and incandescent lamps, tungsten filament treatment are conducting sufficient current to the filament heating to incandescence and glows. The difference is that a halogen lamp glass envelope filled with a halogen element, some of the gas, typically bromo or iodo, in the presence of the halogen element can slow the loss of the tungsten filament at high temperature, extending the life of the filament while the filament can also work at higher temperatures, resulting in higher brightness, color temperature and luminous efficiency. Currently headlights on most cars are halogen lamps.
Advantages:
Simple
structure and low cost.
easy to control and adjust brightness.
Light good color, penetration.
longer than incandescent life, high color temperature, high emission efficiency.
Disadvantages:
compared to the xenon lamp emission efficiency is still low, most of the energy is lost as heat. Life of only one tenth of a xenon lamp
.
The color temperature lower than the xenon lamp.
Halogen works:
When heating a tungsten filament, tungsten atoms evaporated after being moved in the direction of the glass wall, as close to the glass wall, tungsten vapor is cooled to about 800 deg.] C and a halogen atom and together form a tungsten halide (iodide, bromide, tungsten or tungsten). A tungsten halide continues to move toward the center of the glass tube, and back to the oxidized filaments, since the tungsten halide is a very unstable compound, which when heated and then re-decomposed into tungsten halogen and steam, and the tungsten filament so that deposited on the make up of partially evaporated. By this regeneration cycle, the filament has not only been greatly extended service life (almost 4 times longer), and because the filament can be operated at a higher temperature, resulting in higher brightness, color temperature and higher higherLuminous efficiency.
Applications:
Halogen is mainly used as an automobile headlight, a light distribution has a unique structure. Within each lamp has two filaments, one group of the main beam filament is emitted straight forward to light emitted by the shade reflecting mirror, such light sources commonly known ldquo; rdquo ;; beam is another partial beam filament group , the light emitted by the light blocking plate to block the upper part of the globe mirror, which is light reflected off valve diffuse down to the ground, the driver will not cause a dazzling oncoming vehicles, commonly known as such a light source ldquo ; low beam rdquo;