LED Lights

Continued from page 1

By Simson Garfinkel

December 6, 2002

All of the devices mentioned so far use one or more white-light LEDs. But one of the neat things that you can do with LEDs is combine red, blue, and green LEDs to create any color of the rainbow. That's what a Boston, MA company called Color Kinetics (www.colorkinetics.com) does. The company holds a patent on a method to tune the color of LEDs by varying the duration of electrical pulses to the lights, a technique called pulse-width modulation. It has applied this idea to create a range of products for what's called "architectural lighting"-that is, using color to set a mood.

I recently tried some Color Kinetics lights-the Color Blast 16-for a few weeks in my house. At the high end of the company's product line, Color Blast lights cost hundreds of dollars and require special wiring and a separate controller. But like other Color Kinetics lights, the Color Blast combines separate red, blue, and green lights to make white. This should let you dial any shade of white you want, but my wife and I found that the "white" was very cool-not what you would want for home or work illumination. Worse, though, were the shadows: around the fringes you could see little hints of cyan, magenta, and yellow-since it was in the fringes of a shadow where an individual red, blue, or green LED might be blocked.

Color Kinetics is working to overcome this problem by combining a series of white-light LEDs with a few amber LEDs thrown into the mix. The white-LEDs eliminate the multi-colored shadow problem, and the amber lets you tune the color temperature from fire-light to tungsten to a bright summer day. George Mueller, Color Kinetics' CEO and Co-Founder, showed off this unit at a recent talk, and it was pretty slick. Sadly, it will still be a few years before most of us can afford such technology. For now, Color Kinetics offers a more affordable product line, "Sauce," that includes wands, night lights, and bulb replacements starting at $15.

So what does all this mean? Color Kinetics' Mueller predicts that LED headlights and interior lights should start showing up in cars in a year or two-probably in Europe first, since LEDs will allow automakers to use less copper (since the lights require less power), which means lower costs and slightly better gas efficiency.

In the U.S., we'll probably see LED lights infiltrate offices in five to 10 years, around the time they will have completely conquered the flashlight market. LEDs have huge advantages compared with incandescent bulbs: they use dramatically less power, produce negligible heat, and have a 20-year lifetime. As more LED products come to market, we'll see them sweep alternatives aside.