Benefits of LEDs

A brief history of lighting and LEDs

The first artificial lighting was fire. More than 20 000 years ago humans burned oil to obtain light. The candle was created approximately 2000 years ago. The gas lamp appeared in the 19th century and the first filament lamp in 1879.

The first practical light emitting diode (LED) appeared in the late 1960s, using Gallium Arsenide Phosphide. The first LEDs produced only red light. Then orange, yellow and green became available. Blue Gallium Nitride (GaN) LEDs arrived in the mid 1990s. The ultrabright blue chips became the basis of white LEDs, in which the light emitting chip is coated with fluorescent phosphors. These phosphors absorb the blue light from the chip and then re-emit it as white light.

Like computers, LEDs are following their own kind of "Moore's Law", becoming roughly twice as powerful (bright) around every eighteen months. Early LEDs were only bright enough to be used as indicators, or in the displays of early calculators and digital watches. More recently they have been starting to appear in higher brightness applications and the automotive industry has sworn to banish all incandescent bulbs from cars by the end of the decade, replacing them with LEDs - even in headlights!
Very soon, LEDs will be bright enough to light homes, offices, motor vehicles and even provide street lighting. The old filament bulbs will go
the same way that valve radios did.

Some benefits of LED lighting

1. LONG LIFE: The typical working life of an LED is 100 000 hours - that's 11.5 years of continuous light, day and night. Most filament bulbs expire after just 1 000 hours and in as little as a few tens of hours for portable torch bulbs.
2. ROBUST: The filament in a normal bulb is a very fragile object, easily broken by a sudden shock or "soft" drop. An LED is encased in virtually unbreakable high strength optical grade resin. There is no glass or filament to break, making LED light sources perfect for rugged or demanding environments or installations where access is difficult.
3. COST SAVINGS: the long life and reliability of LED light sources reduces maintenance costs, especially in large installations.
4. BETTER SAFETY: The low level of heat produced and low voltages used by LEDs make them a far safer source of light. No glass to break, no hot filament, no gas or candle flames and no noxious fumes. The intrinsic toughness and reliability of LED light sources mean that they are less likely to fail at the times when you need them most (usually in an emergency), thereby raising the user's level of personal safety and security.