Questions about LED headlamps: What you always wanted to know
04-11-2020Not so long ago, we were busy at home replacing our old light bulbs with modern lamps that use LED technology. Why? Because one advantage of LED is that it is much more energy efficient. But LED also offers advantages outside your home, for example on your car. I'm sure you've already noticed: lighting solutions like headlamps for the automotive sector are increasingly equipped with LEDs. We at HELLA have also upgraded some of our products to LED, for example our Jumbo auxiliary headlamp, fitted to trucks.
Now you may wonder: is the whole thing just a sophisticated marketing hype to get the cash register ringing for manufacturers like us, or is there more to it than that? As experts in the field of vehicle lighting, we don't want to persuade you with flowery promises, but rather convince you transparently with honest facts. That's why we answer the most frequently asked questions about LED technology and LED headlamps. Let's go:
Where is LED technology used?
The use of LED technology for modern headlamp systems is one of the greatest innovations in the field of automotive lighting. Since the first light functions were introduced as a centre high-mounted stop lamp at the beginning of the 1990s, LED technology has developed rapidly, culminating in its current use in modern lighting systems such as the matrix HD84 system. LED headlamp solutions are now found in vehicles of almost every class – from small cars to luxury ones in the premium class.
How does LED technology actually work?
A semiconductor crystal is responsible for light generation in an LED. It emits light when it is excited electrically. As with conventional light sources, in LED headlamps the light can also be distributed by using reflection or projector-type systems. One challenge for both systems is good thermal management. The LEDs’ power loss must be effectively dissipated from the LED chip and transferred to the surroundings.
LED light sources use light emitting diodes to generate light. Source: HELLA
Are LED headlamps maintenance-free?
LED headlamps are considered practically maintenance-free and last considerably longer than standard halogen or xenon light sources. With service lives of several thousand hours, LEDs often last for the entire life of the vehicle. Their lifetime is also extended by sophisticated thermal management, something that no modern LED headlamp can do without.
What effect does LED have on road traffic?
The light colour, which is similar to daylight, is particularly pleasant for the eyes and can prevent the driver from getting fatigued. Because the light output is powerful and the road is well illuminated, the surroundings and obstacles can be detected more easily and quickly – a plus point for all road users’ safety. This applies in particular to state-of-the-art LED lighting systems with advanced light functions.
What other possible applications are there?
When it comes to developing vehicles, LED technology provides new, wide-reaching design options, both for headlamps and rear lamps, as well as for interior lighting (ambient lighting). Vehicle manufacturers are offered new potential to differentiate themselves – customers benefit from an attractive, unmistakable vehicle and lighting design.
Is LED technology energy efficient?
In contrast to other light sources, LEDs offer considerably better energy efficiency. This is important not only for keeping costs down but also for lowering consumption: after all, the increased prevalence of electromobility means that, in future, solutions that help to conserve battery resources will be in demand. CO2 emissions can also be reduced by systematically using LED technology, making an important contribution to protecting the environment!
Compared to other light sources, LEDs are significantly more energy efficient. Source: HELLA
What exactly does diagnostics mean when talking about LEDs?
The increasing complexity of high-tech components in modern vehicles requires flexible diagnostic solutions. Successful and (from the workshop’s point of view) profitable vehicle repairs are hardly possible without fast vehicle identification, reliable fault diagnostics, comprehensive provision of data and parts, and professional support. This is where professional diagnostic units, for example the latest devices from the HELLA Gutmann Solutions mega macs series, come into play. These communicate directly with the vehicle control unit, evaluate fault codes, provide repair information, and guide you step-by-step through camera and matrix headlamp calibration procedures, and much more.
Does an LED headlamp have to be adjusted?
The matrix LED high beam must be re-calibrated in certain situations, for example following installation/removal of the headlamp, replacement of the windscreen, wheel alignment of the rear axle, or installation/removal of the front camera. Following adjustment of the low beam, the front camera system must also be re-calibrated, as the high beam loses its learning values in this case.
How do you adjust LED headlamps correctly?
Correctly adjusted headlamps are an absolute must on the road, and should therefore be regularly measured and re-adjusted by a workshop as required. This is the only way to ensure visibility and safety. Until recently, this test was carried out using the so-called "10-meter wall". With this measuring method, a vehicle is placed in front of a light-coloured wall, which has certain markings on it, at a distance of 10 m. The headlamps are then checked or adjusted based on these markings.
This may still be a statutory test method today, but in the format described, it’s best used for checking the lights on agricultural or special vehicles, which have the headlamps installed in a high position. Because the disadvantages of the "10-metre wall" are obvious: a relatively large, light and open wall, and therefore a lot of space, is required, both of which are often not available, especially in smaller workshops. Furthermore, today's modern lighting systems place significantly higher demands on the measuring process. Nowadays, checking and adjusting headlamps is almost exclusively carried out using modern beamsetters (SEG for short). Such devices allow the light distribution to be checked more quickly and with greater flexibility.
What should be taken into account when testing headlamps?
The increasing prevalence and further development of new headlamp technologies and light assistance systems also leads to greater requirements when it comes to inspecting and adjusting headlamps. This not only applies to the beamsetters, but also the measurement environment. A directive was created in Germany to ensure greater precision when measuring and adjusting headlamps. It contains precise information for correctly setting up a standardised headlamp adjustment station.
Are there other things to consider?
Greater demands are also placed on workshops as modern lighting systems are quickly developed. This is because only correctly adjusted (radar) sensors and cameras enable technical assistance systems to function smoothly. Modern LED headlamps sometimes require particular steps during measurement or adjustment.
An overview of the necessary workshop equipment and many practical tips about LED headlamps for vehicles can be found 24/7 online at https://www.hella.com/techworld/au/Technical/Automotive-lighting/LED-headlights-833/
