Passage V

Get the LED In

[1]

It was once limited to the humble role of indicator light on devices such as TVs and radios, the light-emitting diode, or LED, has emerged as a versatile, energy-efficient, and aesthetically pleasing source of illumination. (63) Designers today are using LEDs to create signs, displays, and area lighting that are both alluring and functional. [A]

[2]

Long past are the days when LEDs—semiconductor diodes that produce light when electrical current is properly applied—could generate only a low-intensity red light. Modern LEDs can be made to produce any color including white; can be manufactured to generate infrared or ultraviolet light instead of visible light; and are able to yield a high light output.

[3]

LEDs operate on extremely low voltages relative to standard (incandescent) bulbs. They also directly convert electrical current into light, thus eliminating the need to waste energy on first heating a filament that then radiates light. [B] In addition, LEDs last far longer than standard bulbs. Whereas a typical 75-watt incandescent bulb works for 750 hours. LEDs can endure up to 50,000 hours of use. As the case may be, LEDs are small, shock resistant, and (unlike another often-touted alternative light source, compact fluorescent bulbs) mercury free. [C]

[4]

Commercial designers are among those rushing to catch up in their LED use. The ceiling of an Atlantic City, New Jersey, shopping arcade supports 2,000 small color-changing LED nodes strung on overhead cables to create the allusion of a star field. [D] In Sweden, students programmed color-changing LED projectors to turn a small grove of trees into a “cathedral of light.” LED road signs can consist of nothing more than block letters flashing out simple messages; they can, however, be as elaborate as giant billboards displaying vibrant full-color images.

[5]

LEDs are innovative—they’re costlier to manufacture than incandescents and are vulnerable to temperature extremes—but they offer numerous advantages over traditional lighting. The LED is a young technology with a bright future.