LED headlights are improving and growing in popularity as the auto industry increasingly adopts the technology. As of 2013, there were 20 car models with an available headlamp in this form. This new type of headlight has seen somewhat slow adoption by consumers until recently, with concerns about fog safety, heat, and lamp life being at the forefront. These concerns appear to be have been satisfactorily addressed by the industry, however, if the current trend is any indication.

The lights are also available in lights other than the headlamp. They have also been used in tail lights, running lights, and parking lights. As the technology has improved, the level of adoption by automakers and the public has kept pace. Many drivers seem to prefer the lighting offered by the LED headlight, particularly the h/l beam. Some drivers feel the h/l beam is good enough for both the driver and oncoming traffic in terms of visibility and glare.

H/l Beam

LED-lighting is increasingly being used in headlights. Low beams are usually LED lights at the low end of the market since they are always on, even at times when the main beam with conventional bulbs is on. Car makers are expected to continue adopting this hybrid approach over the next few years. The compact part of the market should also be hybrid because of the cost-effectiveness.

LED-light Applications

Recent advances in technology allow the lights to be used in task lighting and for environmental settings. Their advantages over traditional incandescent lights include lower energy consumption, smaller size, longer lamp life, faster switching, and improved physical robustness. Light-emitting diodes are now found in applications like fog lamps, parking lights, running lights, and traffic signals.

The lights are solid state devices that normally experience very little wear and tear if used within a low temperature range and with low currents. Many of those made 30-40 years ago are still in service today. Although heat can shorten lamp life, 25-100,000 hours of use are typical. The most frequently observed sign of light failure is a gradual reduction in light output. Also, a reduction in efficiency is usually noted. Sudden failures are rare. If you are using these lights in tail lights, you should notice that they are gradually weakening, as opposed to a sudden failure.

UV Lights

LED-lights or ight-emitting diodes are quite different from UV lights. For example, these ight-emitting diodes are two-lead semiconducter light sources resembling a simple pn junction diode.

Phosphor-based Lights

The phosphor form of lighting involves a process of coating the lights of one color with different colored phosphor colors. The finishes products are called pcLEDs or phosphor-converted white LED-lights. Phosphor lights work well, although they sometimes have problems with efficiency losses.

Efficiency losses from the phosphor-based version of the lights are caused by temperature loss and degradation issues. The original wavelength of the light and spectral distribution determine the luminous efficacies of the lights. The luminous efficacy of a standard phosphor-based light is up to five times the efficacy of the original blue light, since the human eye is more sensitive to yellow than to blue. However, phosphor is still the method that is most popular for manufacturing the lights because of the simplicity involved in the manufacturing process.

The output of the lights increases at lower temperatures. This makes them good for uses like in grocery store freezer lighting. Since the lights generate less heat than other bulbs, they are considered highly energy efficient for applications like freezers and refrigerators. One caution is that ice and snow could accumulate on the bulbs in colder climes. This has also sometimes caused problems when LEDs are used in traffic signals in snow-prone areas. One solution is adding an inexpensive heating circuit to the traffic light.

Rise time for the lights is defined as up to 90 percent of the pulse’s maximum value. Rise time is also a function of the light’s capacitance, amplitude, and recombination lifetime. Bulb manufacturers prefer measuring, not calculating rise time.

Using LED-lighting in headlamps has several benefits. One is that the bulbs are cooler, meaning they waste less energy than conventional bulbs. They are more durable, largely because they do not contain glass. They are also brighter and shine on a larger area than other bulbs. They also have less glare and provide better safety in dark or bad weather.

Summary

LED headlights are improving and growing in popularity as the auto industry increasingly adopts the technology. It appears the future is “bright” for this technology (pun intended).