Between two tungsten electrodes of the xenon gas discharge lamp burns a concentrated arc. The combustion chamber is extremely small - a flask made of quartz glass - contains a xenon gas under high pressure and mercury (see below the differences Brenner categories) and metallic salts - a total of less than 1 mg. These are aimed mainly at the color of the rather glowing purple xenon light on the color of about 5000 - 6000 Kelvin lower. Strictly speaking, therefore xenon burner a combination of xenon gas discharge lamp and metal halide lamp.
For the ignition (switched) is a high-voltage pulse is required, with a Zündeinheit through an electronic ballast (EVG, engl. Ballast electrical) is generated. The EDC then provides for a light output control.
For double-xenon headlamps is a technique without flap, the passing beam and the beam consist of a burner as well as separate lenses or reflectors. Vehicles with two double-xenon headlamps have four burners, and therefore also four ballasts.
Since xenon gas discharge lamps, can be broken on a burner does not recognize blown filament. They hold 4 times as long as conventional halogen lamps.
In order for the gas discharge lamp for vehicles on the road to use, you must know the slow light start to be accelerated. The required sequence can be divided into three phases are described:
* 1 Ignition: With a high voltage pulse is - similar to a spark - a spark generated in the originally electrically non-conductive ionized gas and thus a conductive tunnel between the tungsten electrodes creates. This tunnel is the electrical resistance is small and current flows between the electrodes.
* 2 Start-up phase: The lamp is operated with controlled overload. Due to the higher power-operated arc increases the temperature in the flask and quickly to the existing metal salts begin to evaporate, thereby changing the light color. The steam pressure in the lamp and the light output increase. Continue decreasing the resistance between the electrodes, which recognizes the ECU and EDC is automatically continuous on.
* 3 Continuous operation: All metal salts are in the vapor phase, the arc has reached its final shape and the light yield its setpoint. The supply of electric power is now stabilized so that the arc does not flicker.