LED Bulbs & Tubes

 

A LED lamp is a type of solid state lighting (SSL) that uses light-emitting diodes (LEDs) as the source of light. They usually comprise clusters of LEDs in a suitable housing. They come in different shapes, including the standard light bulb shape with a large E27 / E26 Edison screw and the typical Halogen MR-16 shape with a bi-pin base. Spot LED lamps are also available in the well known PAR20, PAR30 and PAR38 shapes. Other models might have a small Edison candelabra E14 fitting, GU5.3 (Bipin cap) or GU-10 (bayonet socket). They include low voltage (typically 12 V halogen replacements are MR-16 & G4) varieties and replacements for regular AC mains (e.g. 110-120 Volt or 220-240 Volt) lighting.

 

Comparison of LED with Incandescent and Fluorescent lamps

 

    CFL bulb
  • Incandescent lamps (light bulbs) create light by running electricity through a resistive filament, thereby heating the filament to a very high temperature so that it glows and produces visible light. A broad range of visible frequencies are naturally produced, yielding a pleasing warm yellow or white color quality. Incandescent light however, is highly inefficient, as over 98% of the energy input is emitted as heat. A typical light bulb produces about about 15 lumens per watt. Standard light bulbs are relatively inexpensive and have a typical lifespan of around 1,000 hours. They work well with dimmers. Most existing light fixtures are designed for the size and shape of these traditional bulbs.
    CFL bulb
  • Comact Fluorescent Lamps (CFL's) work by passing electricity through mercury vapor, which in turn produces ultraviolet light. The ultraviolet light is then absorbed by a phosphor coating inside the lamp, causing it to glow, or fluoresce. While the heat generated by fluorescent lamps is much less than its incandescent counterpart, energy is still lost in generating the ultraviolet light and converting this light into visible light. If the lamp breaks exposure to hazardous mercury can occur. Lifetime varies from 1,200 hours to 20,000 hours for compact fluorescent lamps.
    Philips Master LED
  • LED Lamps LEDs are based on the semiconductor diode. When the diode is forward biased (switched on), electrons are able to recombine with holes and energy is released in the form of light. LEDs present many advantages over traditional light sources including lower energy consumption, longer lifetime (less replacement costs), improved robustness, smaller size and faster switching. They are cool to the touch and do not contain any mercury or other hazardous substances. LED lamps are a new technology, making them relatively expensive. However, in the longer term this investment will lead to larger reductions of your energy-bill.