#Halogen vs hid vs led vs laser full#

In effect, the headlamps become a HD projector with full control over the light beam. The high-beam quality LED light source shines through a mirror array comprising more than a million units.

For example, when Mercedes-Maybach released its facelifted S-Class last year, it incorporated Digital Light. Light-source tech will keep advancing but the major area of change in headlamps will concern the control of the light beam. The US regulations are more conservative than those in Europe (from a technology and brightness point of view), resulting in the delay of laser light and digital matrix (where the permanent high beam illuminates only selective areas to prevent glare) technology reaching the North American market. This includes position, functionality, brightness and even the icons used on the instrument cluster. Why do all modern cars have a pair of headlamps? The reason is legislation (Federal Motor Vehicle Safety Standard, or FMVSS, in the US European commission for Europe, or ECE, in Europe) specifies each detail of vehicle lighting. Pros: More efficient than LEDs (up to 170 lumens per Watt) compactĬons: Extremely expensive (R103 444 per unit on a BMW i8) high beam only Headlight legislation White (close to daylight at 6 500 K colour temperature) Laser lights are used together with LEDs for low beam. Currently, laser lights (used mainly for high-beam applications) are employed in conjunction with one of the other lighting technologies (usually LED) to cater for low-beam operation. The reaction that follows produces intense white light reflected onto the road. Rather, mirrors focus blue lasers onto a lens filled with yellow phosphorus. No, lasers are not actually pointed at the road ahead in the fashion of a sci-fi ray gun or phaser. Pros: Efficient (100 lumens per watt) powerful compact long service lifeĬons: Expensive (R59 480 per unit for a BMW i8, for example) complex cooling requirements Laser LEDs are commonly used for daylight-running lamps because their lower power outputs mean no cooling measures are required. To compensate, cooling measures or heat sinks must be implemented to prevent damage. Compared with halogen, little heat is dissipated, presenting a problem with temperature build-up on the LED chips, especially in high-power applications. Interestingly, the light produced is directional, thereby eliminating the need for a reflective element, which results in a smaller headlamp. It involves semiconductors with electrons moving from a high-energy state to a lower level and releasing energy in the form of photons (light). The light-emitting diode (LED) produces light by electroluminescence, which is based on quantum theory. Pro: More efficient and powerful than halogen bulbsĬons: Takes a few seconds to reach full brightness more complex and costly than halogen LED White with a blue tint (4 500 K colour temperature) Bi-xenon refers to a single xenon headlamp with a moveable, internal shield to produce both high and dip beams from a single light source. The lamp needs to reach optimal operating temperature before constant light is produced. Interestingly, only a small percentage of xenon gas is used in the (mostly metal-halide) lamp to speed up the start-up process. Instead, a high-voltage arc between two electrodes is used to excite the gas mixture in the glass tube. There is no glowing filament (as in halogen lights). It employs a similar type of technology as found in household tube lighting. Pros: Cheap (R200 per bulb) simple technology easy to replaceĬons: Energy wastage, as it runs very hot (the gas inside the glass envelope heats up to 200 ☌, with the tungsten filament at more than 2 000 ☌) HID (xenon and bi-xenon)Ī high-intensity-discharge (HID) headlamp is also known as a xenon unit. It’s cheap, simple tech that is easy to replace. This results in the production of constant light throughout its operating life. The “halogen cycle” redeposits the evaporated tungsten back on the filament, which prolongs its life and keeps the glass envelope clean.

Usually, a tungsten filament is employed in the glass housing filled with a mixture of an inert gas (like argon) and a small amount of a halogen (as listed on the periodic table, such as iodine or bromine).

HalogenĪ bulb with glass envelope (similar to the household item) operating on the incandescent principle. The figures are for a single headlamp consisting of a high and low beam. These are the four most common forms of automotive lighting used in headlamps.

Halogen vs hid vs led vs laser