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Bright lights, big savings: LEDs arranged in the holes of the PVC mounting plate.

MY LOVE AFFAIR WITH LEDS

Build a bright, low-powered desk lamp.

By Charles Platt

Quartz halogen lamps are more efficient than old-fashioned incandescent bulbs; fluorescents are more efficient than quartz halogens; and white light-emitting diodes (LEDs) are the most efficient of all (if you consider the ballast that is needed by fluorescents). So why haven’t white LEDs become as fashionable in homes as a Prius in the driveway?

Photography by Charles Platt

One reason may be that a white LED isn’t quite white. It has an eerie purplish tint. This doesn’t seem to bother people when the product is a flashlight, but it has been a barrier to the application of LEDs in domestic settings. Personally, I like freakish technology that looks as if it came straight out of The Jetsons, so a purplish tint is fine by me. With this in mind, I set out to be the first on my block to have an LED desk lamp.

After an unproductive attempt to find ultra-high-power LEDs using Froogle, I tried eBay and hit pay dirt. Hong Kong manufacturers are now accepting PayPal for state-of-the-art LEDs ordered by the hundred, and are charging less than 25¢ per diode. Diodes are 1cm in diameter and have a claimed light output of at least 100,000mcd.

Now, you may be wondering what this “mcd” measurement is. It stands for “millicandles,” which is confusing, since old-fashioned light bulbs are rated in lumens. A lumen measures the total amount of light emitted in all directions, whereas a millicandle is a measurement of intensity per unit of area — more appropriate for an LED since it has a lens that emits a tightly focused beam, often as narrow as 5 or 10 degrees.

Make: 133