Out in the market looking for a new car? Let’s face it. Car manufacturers throw a lot of features at us these days. Cars come in various trims, models and with different engine options. Adding to the chaos is the fact that there are several car brands out there catering to every budget.
A few years back, you wouldn’t have had to bother yourself with the headlights of a car. But not today. Compare car brochures and you’re likely to find terms like xenon lights, DRLS etc. Fret not, because in this article you’re going to learn about the various kinds of headlights used in automobiles and your life is going to be that little bit easier when you walk into the next car showroom!
Commonly referred to as halogen bulbs, these headlights are what you’ll find on most cars. A halogen bulb is basically a tungsten filament surrounded by inert gas and a small amount of halogen gas such as iodine or bromine. The tungsten filament and the gas are housed in a glass envelope which forms the bulb. The bulb is placed at the focal point of a reflecting concave casing. This entire unit forms the headlight. The beam of light produced is bright and scatters over a large area. This kind of headlamp has been used for decades and it’s not particularly known for its efficiency. A lot of the input energy given to the lamp gets wasted as heat. Furthermore, reflector headlights can be blinding to the oncoming traffic especially when used in high beam mode. It is still popular today as it is very cheap to manufacture. Hence you will find this commonly in lower-priced cars.
When you look at higher variants of budget cars you will find projector headlamps. Projector headlamps use halogen bulbs like reflector headlamps. However, you will find the halogen bulb contained within a spherical lens. This lens doesn’t allow the light beams to spread as much as they do in reflector beams. So essentially, the lens focuses the light beams on where it matters-the road ahead. This makes projector headlamps appear brighter than reflector headlamps. Since both use the same halogen bulbs, the energy consumed will be the same.
Effectively, this headlight uses a laser beam to illuminate the road ahead. Laser beams are highly monochromatic and have a very low divergence rate. This results in a very intense beam of light. Also, for every watt of power consumed, lasers produce a brighter beam of light when compared to LEDs. The downside, however, is its cost. Being very expensive to produce, laser headlamps are now restricted to cars that only highly wealthy individuals can afford. Case in point, the BMW i8. Laser lights might become more common in the future. But for now, it remains exclusive to ultra-premium cars.
HID (High Intensity Discharge) Headlamps
These headlamps use a HID bulb in a spherical lens casing. Essentially, it’s a projector headlamp with a HID bulb instead of halogen. In a HID bulb you’ll find two tungsten electrodes surrounded by a noble gas such as xenon. Typically HID bulbs produce a brighter beam of light for the same energy when compared to a halogen bulb. You won’t find HID bulbs with a reflector casing as this would be extremely bright to oncoming traffic. HIDs produce a white beam of light while halogens produce yellowish beams. HID headlamps is something you’ll find on premium cars likes BMW’s and Audi’s.
LED (Light Emitting Diodes) Headlamps
LEDs have replaced most other forms of light sources in the past 5 years or so. And for a good reason. Being so efficient in their energy consumption, today you’ll find LEDs in many applications- streetlights, TVs, household lighting, portable gadgets, flashlights etc. The auto industry seems to be embracing this technology too. LEDs are slowly replacing HID headlamps in premium cars. LEDs are brighter than HID lamps and also consume lesser energy. Hence, it seems pretty obvious that premium car manufacturers are including LED headlamps in their cars.
These are basically small LEDs which are placed strategically in the headlights of a car. The primary purpose of this is to help oncoming traffic and pedestrians, easily identify the car during daytime. Although it’s primarily intended to be a safety feature, car manufacturers try to pitch this feature from an aesthetic standpoint. DRLs come in different shapes. From the cat-eyes of BMWs to the sleek and sophisticated lines of Audis, DRLs add tremendously to the sex appeal of a car. In the future, auto regulations might make DRLs a mandatory feature across all cars. Until then, this will be confined to the premium segment.