In the current Headlight aftermarket, there are many types of headlight bulbs such as HID bulb, LED bulb are used for retrofitting. Many car owners upgrade their car lights with different headlight bulbs to reach their lighting requirement. Today, we would like to talk about the four important headlight bulb in the headlight history.
Before talking about the halogen bulb, we need to know about the incandescent bulb. The incandescent light bulb is an electric light with a wire filament heated to such a high temperature that it glows with visible light, but the lifespan is too short.
In order to improve the incandescent bulb durability, people input halogen gas into the bulb, so the halogen bulb comes out. The sublimed tungsten filaments get a chemical reaction with halogens at high temperatures. And then will resolidify on the tungsten filaments to reach a balanced cycle to avoid fracturing. For the result, the halogen bulb life-span takes longer than the incandescent bulb.
Since the light emits from halogen bulb is in 360 degrees, it can not be focused that would cause dazzling oncoming traffic on road and waste lots of effective light. So people made a reflector to spot light beam. Later then some car manufacturers create a projector for replacement of the reflector to improve the headlight appearance and the spotlight ability. However, a halogen bulb is not bright enough when working with the projector, it is going to be dimmer than before. So it does not work well the projector but performance better in the reflector.
The HID bulb is full of Inert mixture gas includes Xenon. It breakdowns the xenon by high pressure to produce an arc between two electrodes to light up the bulb. There is no tungsten filament in the bulb body, so the HID can be used for a longer time. The lifetime of HID is 10 times that of the halogen bulb and the brightness is three times that of it.
Many car owners would like to install HID bulb instead of halogen bulb for their car. But some factory vehicles do not match with a projector in the housing. There will be an issue when installing the HID bulb in the housing, the OEM reflector cannot spot light beam because the position and shape of the HID bulb could not fit the reflector. At this time, that would be easy to cause a dazzle oncoming traffic because of the scattered beams.
On the other side, the HID bulbs usually emit white or even bluish light. The penetration of yellow light is better than both the white one and the blue one. It will be weaker than the halogen bulb when on a rainy day. So people tend to install yellowish fog light to match with the HID headlight in order to see the road clearly in a rainy and foggy day.
Although HID provides high brightness for driving, people still did not satisfied with it. They made another bulb use in the automotive lighting --- LED (Light-emitting diode). Here are some merits LED bulb as below:
1. Energy conservation
LED are twice as efficient as fluorescent bulbs. The energy consumption of LED for a vehicle is only 1/20 of halogen bulbs.
2. Long lifespan
At present, the LED automotive headlight can last for 50000 hours when halogen lights just can last for only about 3000 hours.
3. Good durability
Due to the simple structure of the LED bulbs, the shock resistance is better and it can adapt to various environments.
4. Small volume
LED components are small, so it is easy to be placed in compact space. It can meet the requirements of the lights for the manufacturers.
5. Quick response
The lighting of the LED is a microsecond which can be used in the vehicle for a better response.
6. A low requirement for environment
LED units can be driven by low voltage direct current and it is housing with low load.
When we mention LED headlight, your guys may remind another stuff, Audi OEM matrix LED headlight. By light up and crush out with a single LED bulb, Audi created a dynamic turn signal light. This LED matrix headlight can detect ahead traffic vehicles. It will automatically adjust or close several LED monomers in the light group to protect them from the strong lighting penetration. The LED element gives more development for the automotive lighting with more capacity and advanced.
Recently, some automotive manufacturers created a new headlight technology --- Laser headlight. It can emit and control the direction of the light beam through a projector. The Laser diode is the core of Laser headlight. A single laser headlight element is smaller than LEDs, it's 1/100 of the LED size. The benefits of laser headlights are high brightness and long illumination distance.
Although the irradiation distance of Laser headlight is throwing on the road with long distance and high brightness, the range of irradiation is limited. It needs the LED bulb to supplement the lighting. The world's first mass production vehicle manufacturer used Laser headlights is Audi R8 LMX. The biggest feature of this vehicle is the use of Laser headlights. BMW i8 also install Laser headlights. BMW and Audi are now equipped with Laser headlights on their mass production vehicles.
In general, the classification of the headlight bulb is halogen, HID and LED (the Laser headlights are not popular, which is not mentioned here), and it is easy to distinguish them. But whether it's an HID headlight or LED headlight, some of the most basic things is that we need to comply with the Road Safety Rules. Even if your headlight emits awesome lighting with high brightness, there's no need to cause a dazzle oncoming traffic. Driving safe is more important.
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