ARTC Develops LED Lamps for Motorcycles

The government-backed Automotive Research and Testing Center (ARTC) has recently unveiled several proprietary LED (light emitting diode) lamps for vehicles, with one prominent for Harley Davison motorcycles and another for general sedans.

The Harley Davison LED headlamp is the result of cooperation between the ARTC and auto-lamp designer Mycarr Lighting Technology Co. Equipped with four three-watt LED bulbs, the lamp produces up to 280 lumens of dipped beam at six watts and 560 lumens of main beam at 12 watts, bringing energy savings of more than 80% compared with halogen lamps.

According to the ARTC, the toughest challenge its engineers faced when designing this lamp was identifying the optimal thermal-dissipation design for a completely sealed lamp housing. “You have to take into account system reliability, lifespan, and effectiveness, all of which are determined by thermal-dissipation quality,” comments Dr. R.T. Hsu, a senior research fellow at the center.

The solution was to place aluminum fins on the base of the LED module and a ventilation inlet below the lamp's front side, successfully keeping P-N junction temperature on the LED package substrate under 74 degree Celsius. “Even under high ambient temperature, the lamp can operate normally,” Hsu stresses. This heat-dissipation performance, he notes, is above market standards and meets the U.S. FMVSS108 S7.9 standard, which governs heavy-duty motorcycle headlamps.

Mycarr, which came to ARTC for technological support after receiving a query about developing the lamp for Harley Davison, will start shipping the lamp in the second half this year after it passes testing by the Automotive Manufacturers Equipment Compliance Agency Inc. (AMECA) of the United States.

ARTC points out that the lamp can be used as an original equipment manufacturing (OEM) Harley Davison component or as a replacement for original lamps.

Hsu notes that the lamp incorporates some of the center's patented technologies, including a multi-reflective lens design which boosts light output by at least 10%.

The Harley Davison headlamp was introduced about the same time as another LED headlamp for heavy-duty motorcycles that the center co-developed together with the Gsharp Corp.

The introduction of the two LED headlamps has sparked market speculation that the ARTC intends to help Taiwan's vehicle industry overcome the competitive hurdles erected by international carmakers that hold LED headlamp patents by skirting car lamps in favor of motorcycle lamps. “The chances of Taiwan's vehicle industry coming up with patented LED headlamp designs is fairly low, because the big international players have taken almost all of the patents you can think of,” Hsu laments. “I'm afraid that Taiwan's manufacturers will, in the end, serve as OEM suppliers to the patent holders, just as most local manufacturers in other industrial sectors do.”

Hsu sees some hope, however, as most of the international patents are for secondary optic lens, or reflective structure, designs. “Primary optic design for LED packages is a good entry point on the way to design patents for Taiwan's auto-lamp makers,” he says, adding that the ARTC is concentrating on primary optic designs. Hsu's computer simulation indicates that primary optic lenses can offer 22% more light than secondary optic lenses.

Although the center has yet to introduce a commercialized primary lens design, it has rolled out an LED headlamp lighting system that makes the most of optical fiber, a system which the center codenames “Light Engine.” According to Hsu, the use of optical fiber to transmit light emitted from LED lamps to headlamps in this system is already patented. “Unlike existing patented designs featuring LED lamps installed right inside the lamp cases,” he explains, “our LED lamps are installed in the luggage compartment, far away from engine heat. As you know, heat is the major killer of LED lamps.”

The “Light Engine” system uses 20W LED lamps, each driven by 700mA to 1000mA, to generate 610 lumens, along with 1,000mm-long optical fibers 10mm in diameter. The case uses non-spherical surface lenses with a focal length of 20mm and a refractive index of 1.5028. (July 2010)