What are LEDs?
LEDs, or Light Emitting Diodes (a diode is a device that only allows electricity to flow through it in one diretion, which is why LEDs have a positive (+) side and a negative (-) side) are silicon wafers that emit photons (light) when an electrical current passes through it. The most common uses of LEDs are in consumer electronics and other equipment as indicator lights (the green or red ‘power on’ lights on a VCR or computer monitor).
Only with the recent introduction of HB (High-Brightness) LEDs and HF (High-Flux) LEDs, have LEDs been considered a “useable light source” for flashlights, accent lighting, sinage, general-illumination and other applications.
The most significant distinction between traditional lighting devices (an incandescent light bulb, floruesent tube, neon fixture, etc.) and LEDs is that LEDs do not use heat or a gas to generate light. An LED is a ‘Solid State’ device that contains no fragile filament or glass tube, making it an extremely durable and reliable light source that can be used in ways never before possible.
Where are LEDs being used?
LEDs are used in applications where long life and reliability is required. Many have been illuminated for 25 years and continue to function. Because LED use much less current than other light sources and run on low voltage DC, they are naturally suited for many battery powered applications. In very cold temperatures, LEDs turn on instantly while some fluorescents would fail to light. LEDs also generate smaller amounts of heat than their incandescent (filament) counter parts.