WHAT ARE LEDS? December 15, 2016 11:17
Some Colourful LEDS
Image Courtesy of thctalk.com
What does LED stand for? It stands for Light Emitting Diode. The Diode is a tiny piece of semi-conductor material at the very centre and wow are they emitting some light or what?
The old-fashioned electric light bulb was first patented by Thomas Edison in 1879.
It used a thin sliver of bamboo that was heated until it glowed.
Edison knew that of all the elements tungsten had the highest melting-point, but it wasn’t until 1910 that a method of manufacturing thin strips of it, called filaments, was developed.
Tungsten was used thereafter for light bulbs and they held sway for a century or so from then on. They produced light by heating a filament of tungsten until it glowed white hot, effectively “burning” it. Of course, with the best will and technology in the world they “burnt out” sooner or later.
By contrast LEDs produce light at a sub-atomic level in a similar way to the transistor amplifies sound and revolutionised the radio. This means they are much more efficient than old-fashioned bulbs, incredibly long-lasting and also produce virtually no heat.