The principle behind automotive high-voltage xenon lamps is to use a booster to instantly boost the vehicle’s 12V DC voltage to 23,000V. This then creates a bipolar arc, without the need for a tungsten filament, and the high-voltage amplitude excites xenon electrons within the crystal glass tube, generating a bright, daylight-like light source between the two electrodes. HID xenon lamps are poised to replace traditional halogen lamps, a major trend in automotive development.
Original halogen headlights typically consume around 55-105W of power. However, HID headlights, stabilized by a ballast, draw only half the operating current of halogen lamps, requiring only an average of 35W to power the xenon bulbs. This energy savings translates into fuel savings.
A typical HID lamp’s luminous flux is approximately 2,400 lumens, more than three times that of a standard halogen lamp. The color temperature of HID lamps ranges from 3,000K to over 12,000K; the higher the color temperature, the less effective it is in penetrating fog and rain. Light around 6000K is the whitest, slightly blueish color temperature, closest to midday sunlight and most receptive to the human eye. Using this type of lighting for nighttime vehicle illumination can effectively reduce driver visual fatigue. The increased brightness also effectively expands the field of vision ahead, creating safer driving conditions.
Because HID lamps lack filaments, they are not subject to the risk of filament burnout. Their service life is significantly longer than that of halogen lamps, exceeding 2800 hours, ten times longer.
The arc characteristics of high-pressure xenon gas indicate that it is convection-stabilized. If the xenon lamp is turned horizontally, the arc will bend upward, changing its shape and photoelectric parameters. Especially when convection is excessively strong, the arc will drift upward severely, or even extinguish. Therefore, the use of a magnetic field to stabilize the arc is essential. Low-power xenon lamps with short interpole distances are an exception, as their arc is transiently stabilized. The brightness characteristics of xenon lamps show that the distribution of light between the cathode and anode is very uneven. However, a cathode spot exists near the cathode, resulting in extremely high brightness. Therefore, the reflector design should maximize this advantage to achieve high light utilization.
Xenon lamps operate under extremely high pressure, and the surface temperature of the bulb can reach 800°C. Therefore, the air flow rate within the projector must meet the required xenon lamp speed. This reduces the chance of lamp failure, slows down lamp blackening, and prolongs lamp life.
Currently, one of the main causes of high-pressure xenon lamp failure is burnout of the lead wires. In addition to manufacturers improving the lead wire manufacturing process, this can also be caused by improperly tightening the power cable and cap during installation, resulting in poor contact and increased contact resistance. When high current flows through this point, high Joule heat (Q=I²R) is generated, creating a hot spot, further increasing the contact resistance and heat. This vicious cycle generates high heat and ultimately burns out the lamp holder (lead wires).
If a xenon lamp exhibits arcing (horizontally ignited) after a period of use, turning the lamp 180° after turning it off can prevent this and extend its lifespan.
It is recommended that new lamps be operated at 70% to 80% of the rated current. The operating current can then be gradually increased as needed (but not exceeding the specified maximum). This will extend the lamp’s lifespan.
The current ripple coefficient of the power supply used for lighting must be less than 3.5%, and the lower the better. Furthermore, the inrush current at the moment of lamp startup must be kept to a minimum, as this will significantly damage the lamp’s electrodes and shorten its lifespan.
The lamp should be replaced promptly after reaching its specified lifespan. If the bulb becomes severely blackened during use, the lamp should be replaced. Otherwise, the bulb will overheat and explode.
Post time: Aug-11-2025