Light emitting diodes or LEDs are appearing in more and more products. Flashlights are a typical example of this – using new technology in old products. If they are becoming so popular what are the advantages of LEDs over traditional bulbs?
LEDs produce light through a different method than incandescent bulbs and it is their means of light production that creates the benefits. A LED is composed of two semiconductors. When an electrical charge is applied, electrons move between the semiconductors and light is emitted. This produces less heat than a traditional bulb that uses a filament wire inside a vacuum tube.
At low energy levels, LEDs are much more efficient than normal bulbs. Any heat that is produced is wasting energy and decreasing efficiency. The heat produced in glass bulbs in time causes the filament to burn out and need to be replaced. LEDs do not have this problem and they have been known to illuminate continuously for over 10 years.
LEDs are much less fragile than glass bulbs and can usually survive being dropped with no damage. This combined with efficiency are their two major advantages.
As reliability is a key characteristic of good flashlights, LEDs are perfectly suited to this application. Their efficiency is particularly important as it greatly extends the battery life of the flashlight. This fact has also made LEDs very popular in headlamps for hikers and climbers, particularly on longer expeditions. Not having to worry about a planet burning out is also important when far from civilization.