IRVS VLSI IDEA INNOVATORS

IRVS VLSI IDEA INNOVATORS
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Friday, July 22, 2011

A19 LED bulbs: What’s under the frosting?

Standard A19 format light bulbs, found today in most lamps and luminaires, are now available in LED versions that retail between $20 and $40 per 40-W- or 60-W-equivalent bulb. Some bulbs are dimmable, some not, and some only with specific dimmers. They all advertise 25,000 to 50,000 hours’ expected lifetime, based on three to four hours’ daily usage. If you use them appropriately and sparingly, you might expect your light bulbs to outlive you.

Each of the bulbs comes in a specially designed package, unlike tungsten filament and CFL bulbs, which ship in nondescript shrink wrap. The fancy packaging adds to the overall cost.



These bulbs clearly are not yet positioned as commodity items; they are expensive and are expected to last. But the price of electronic gadgets has dropped so much of late that longevity is no longer the main concern. So why is a common light bulb more expensive to buy than a cheap digital camera?

Looks count in a category as simple as light bulbs, and each of the bulbs we examined has a unique appearance. For example, the GE bulb has a ceramic neck and fins and a glass bulb, and is more costly than those using plastic and metal.

All of the bulbs have a small printed-circuit board contained within the neck, relying heavily on large electrolytic capacitors and transformers. The reliability factor of LEDs has increased tremendously.



All of the bulbs have a small pc board within the neck, relying heavily on large electrolytic capacitors and transformers.

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