The Journey of Headlights

The Journey of Headlights

Car headlights, years ago it was just a part of car or vehicle to light up the way in dark areas or at night. Nobody gives much importance to headlights and no one is going to pay more attention to the headlamps. As the new era comes and technology develops, headlights also get new definition. The world of headlights is a bit of a minefield if you are part of the uninitiated. Headlights have become a fashion statement now for the cars, like they are telling us “look at me, admire me”. Currently four types of bright eyes are used in a vehicle – halogen bulbs, HID or Xenon, LED, and Laser headlights.

Halogen lamps are usually fitted in all type of vehicles, mostly in lower segments. While HID lights can be found in some premium cars. LED headlamps are the charm nowadays, all the luxury cars use full LED headlamps with projector lamps. Finally the Laser lights; they are very high intensity lights used by giants like BMW (BMW i8) and Audi (Audi R8 V10). LED lights are gaining popularity rapidly since a decade and also it looks premium but affordable. In this article we are going to compare all four types of headlights with their pros and cons. Let’s start with the halogen headlamps.

Halogen Headlamps :

From the mid-1960s until now, these tungsten filaments have been encased in a bubble of halogen gas in order to improve performance and longevity. Halogen headlamps are made of a glass tube filled with halogen gas (mixture of argon and nitrogen) and the tungsten filament. When the bulb receives electricity from the car’s battery it heats up around 2500 0 Celsius and thus it starts glowing. The glass tubes are strong enough to bear the high temperature of the filament. Halogen lights are still very popular in auto-industry because of it’s ease of fitting and replacement.

halogen 1

An average halogen bulb’s life is around 1000 hours in decent working conditions and an estimated colour temperature of the halogen bulbs is around 3000K to 5000K. But there are some major issues with the halogen lamps. It generates more heat and more heat is nothing but waste of energy, quite literally.

Pros –

  • Easy to install
  • Cost effective
  • Simple construction
  • Different dimensions
  • Long lasting and dimmable

Cons –

  • Waste of energy
  • Brightness issues
  • High power consumption
  • Does not work properly in foggy weather

But modern halogen headlamps come with advanced computerized designed reflectors which provide more brightness and visibility.

HID (High Intensity Discharge) or Xenon headlights :

HID or Xenon lights are famous for their bright white lights, it is actually three to four times brighter than the halogen bulbs. In 1991, for the first time ever BMW had introduced Xenon lights in BMW 7-Series and since then to now, these lights come as standard in many cars. HID lamps produces bright light with the help of different types of gases and metals.

HID 2

How HID lamp generate light?

When the electricity or high voltage reaches the system, it ionizes the xenon gas and creates a flow of current between the electrodes. Then the bulb heats up rapidly and vaporizes the metal slate which lowers the resistance between two electrodes. Ballast switch continuously supplies the power, which starts the flow of bright light. In HID lamps, Xenon gas prevents flickering of arc.

HID 1

HID lamps have a long life span of approximately 2000 hours and estimated colour temperature between 4000K to 6000K. Generally, HID lamps consume 35 watts. There is also another form of Xenon lights, called ‘Bi-Xenon’. In that setup the Xenon lights are only provided for the lower beam and for the higher beam halogen setup is there.

Pros –

  • long life span
  • better visibility
  • more efficient

Cons –

  • high cost
  • too much glare for oncoming vehicles
  • complex structure
  • take some time to reach full brightness

LED headlights :

LED (light emitting diodes) headlights are the latest invention in auto industries, most of the car companies offers LED headlights in their top cars. The working principle and the construction of the LED headlights is sort of difficult to explain but in simple words, it works on negative electrons moving towards the positive holes across a semi-conductor. When that negative electron falls into the hole it sits on lower energy and it will lose the energy, resulting in it leaving a photon. This process repeats thousands of time and generates a bright light from a 2mm LED.

LED 1

LED headlights provide much better light than halogen and HID lamps and it works on low power and does not waste energy by heating too much. The most impressive thing about LED is, that it is smaller in size so it is easy to manufacture different size and shapes for LED headlights. The use of LED lights in brake lights and side indicators is an evolution. A study says that it is 30 percent quicker to identify a warning indication in case of LED lights.

LED 2

Pros –

  • small in size
  • costumes less power
  • brighter than halogen and HID lamps
  • more focused rays

Cons –

  • very costly
  • complex design

Laser lights :

We can say laser lights are the future of headlights, though it is implemented in some of the very expensive cars like BMW i8 and Audi R8. Laser light technology is far better than LED lights and manufacturers like BMW and Audi are pushing to make it happen. But,it is also true that laser lights are harmful, so how it will work? Let’s check it out.

Pursuant to BMW, our system uses three blue lasers positioned at the back of the headlight assembly, firing onto a set of tiny mirrors that focus their energy into a tiny lens containing yellow phosphorous gas. This substance loves to create a very bright white light when coming in contact with laser beams and this resulting light is then reflected towards the front of the headlight. So basically, you’re looking at the light created by the phosphorous, not the laser itself, which makes the system road usable.”

laser 2

Laser technology will generate 1000 times brighter lights than LED and it will use half of the power than LED with the colour temperature of 5,500K – 6,000K.

Like BMW, Audi’s laser system works similarly but Audi uses 4 lasers per headlamp.

lase 1

Pros –

  • highly efficient
  • very compact
  • 1000 times brighter than LED

Cons –

  • Extremely expensive
  • Needs cooling system
  • Currently not in use for normal cars

So, all types are done, it’s now your choice to pick from the three (obviously Laser lights are not there for now).

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