Cars have always had yellowish headlights traditionally. But nowadays, you would find cars featuring headlights of blue color. Blue headlights are sometimes installed in cars at the factory itself, before the car is offered for sale. While, at other times thee headlights are installed in cars by car owners.
Blue headlights are referred to as “HID (High Intensity Discharge)” headlights. As the name suggests, these lights have more brightness than the normal halogen headlights. Since the technology working behind these headlights is quite new and advanced, these lights are relatively more expensive. So, you would find these lights only on the luxury cars in the present times. But these lights are likely to become popular in a few years and the cost is also expected to come down.
Blue Headlights have Greater Brightness than Normal Car Headlights
The common types of car headlights are – electromagnetism panels, fluorescent lights, lasers, gas camping lanterns and halogen lights. The technology behind all these lights excites atoms in order to make them produce photons. In case of gas lanterns and halogen bulbs, the excitation is done using heat. In other common technologies behind headlights, the excitation is created by light or different forms of electricity.
Halogen bulbs are the most commonly used as Driving Lights. The new blue headlights employ an entirely different technology, called as High Intensity Discharge (HID).
Technology behind Blue Headlights:
In traditional headlights, light is produced by heating a small filament of metal. On the other hand, in HID lights, a plasma discharge arc is created between two electrodes of tungsten. This plasma discharge is responsible behind generation of the blue color. The technology is not entirely new. It has a lot of similarity with the technology behind the bright lights which lighten up the roadways and stadiums.
You can find HID lamps around you in the form of sodium vapor and mercury vapor lights which serve as stadium outdoor lighting and street lamps. The reason behind the popularity of these lights is their efficiency. Sodium vapor lights have an efficiency that is twice to that of normal florescent bulbs.
The technique of light generation used in sodium and mercury vapor lights is quite similar to that employed in fluorescent lamps. In fluorescent lights, mercury vapors in low pressure producers plenty of UV light, which leads to the excitation of the phosphor coating present in the tube. However, mercury vapor lamps contain a gas at high-pressure. Here, the distance between two electrodes is quite short, and the light is generated directly without requiring any phosphor.
HID headlights employ a similar high-pressure technology. The lamp here is quite similar to the mercury vapor lamp. However, mercury vapor lamps suffer from one problem that required to be solved while designing HID lights. This problem is the long start-up time, commonly needed by mercury vapor lights. Xenon has eliminated this start-up issue with the help of a special controller. These techniques have raised the cost of HID headlights.
Blue headlights have a lot of brightness and are ideal to be used while driving in curvy roads, rain and fog. Owing to its greater brightness, these headlights can more effectively penetrate snow, rain and fog as compared to halogen lights. These lights also have greater level of energy efficiency than halogens.