LED stands for light emitting diode . It is a solid state device, made in much the same way as transistors, integrated circuits and microprocessors. It converts electric energy into light energy without generating significant heat. LEDs operate on low voltage DC power supplies at very low current. As they have no glass bulb, no tiny wire filament and no gas, they are both electrically and mechanically rugged.
Since they were invented in the 1960s, they have been used in millions of electronic and electrical devices. They have a long history of longevity and reliability; most outlast the device they serve, and many are still in use after 40 years.
Until recently LEDs were restricted to very low light output and a limited choice of colours, but recent technical advances have produced a new generation of high-brightness LEDs which can match or exceed the performance of traditional lamps.
Incandescent and fluorescent lamps produce predominantly white light and must be filtered to block all but the desired colour, which causes a loss of brightness. LED colours are produced within the lamp, so no filters are required. The LED produces its own colour at full brightness.
The technology is still new, so the LED’s working life is difficult to predict. Manufacturers’ laboratory tests indicate that the new lamps will fade to half their brightness after 60,000 to 100,000 hours.