I bought my first LED flashlight about ten years ago. It was a handy keychain with a button-cell battery. Since then, LED flashlights have evolved and new models have more luminous lights and more LEDs.
Light-emitting diodes or LEDs are solid-state transistors which give off light when electricity passes through them. However unlike incandescent lamps, there are no filaments, and no bulbs. It doesn’t burn, nor generate much heat. And best of all, it consumes a small amount of power.
The small energy footprint makes the bright LED flashlight a very green proposition. It doesn’t need a large energy source to create light and it doesn’t create lots of heat either. And since it’s a single diode, it has a long life span.
Although common LEDs come in a variety colors, the LEDs used in flashlights tend toward a bluish tinge. This is not really a obstacle to having a shiny flashlight. In fact, on sale now small projectors which use LEDs for the lighting element.
The rechargeable LED flash light come in a variety sizes. There are the thumb-sized models which are smaller than a thumb, with larger units using multiple of LEDs. Using arrays LEDs, the size of a lighting unit can be as large as any normal flashlight, with a wide range of designs. There was even one design which make use a circular array of LEDs for a flashlight lamp inside the reflector unit, which also had a rectangular bank on the side but without the reflector unit. This could come in handy when camping, replacing portable battery powered fluorescent lights.
