Wednesday, January 04, 2006

Move over, Edison: An efficient light for your home that will never burn out

Not to sound overly dramatic, but the LED (light-emitting diode) is on its way to offing incandescent and fluorescent bulbs. LEDs use a small fraction of the energy of traditional bulbs, don’t flicker and, amazingly, last for decades. That’s because they generate light by moving current through durable semiconductors instead of delicate, super-hot filaments that quickly burn out.

LEDs have been used since the 1960s for indicators such as the on/off light on your stereo. More recently, engineers have found ways to use them everywhere from traffic signals to automotive taillights to video screens. The challenge of producing an LED lamp for the home, though, has been packing enough diodes together to get the illumination of an incandescent in a compact case that won’t overheat.

Mesa, Arizona, lighting manufacturer Enlux responded in two ways. First, it removed diodes from their individual plastic housings and clustered them on the surface of a small circuit board, known as a light engine. The board dissipates more heat than an array of separately packaged bulbs, so more LEDs can be crammed inside the lamp. Second, a finned aluminum housing spreads the heat that is generated over a greater surface area. The 22-watt Flood ($80) gives off about as much brightness as a 45- to 65-watt incandescent and lasts 50,000 hours (35 years at four hours per day). But with companies all over the world chasing Enlux down the LED path, it shouldn’t be long before we get even brighter options.

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