I had my first LED flashlight almost ten years ago. It was a small keychain using a button-cell battery. Ever since, LED flashlights have advanced a lot and today’s models have shinier lights with more LEDs.

Light-emitting diodes or LEDs are solid-state transistors which give off light when electricity passes through them. But unlike incandescent lamps, there are no filaments, and no bulbs. It doesn’t burn, nor generate much heat. And best of all, it uses a small amount of power.

The small energy footprint makes the bright LED flashlight a very promising approach. It doesn’t have to use a large battery to generate light and it doesn’t produce lots of heat either. And since it’s solid-state, it has a long life span.

Although common LEDs come in a wide range colors, the LEDs used in flashlights tend toward a bluish tinge. This is not really a impediment to having a luminous flashlight. In fact, currently there are small projectors which use LEDs for the lighting element.

The rechargeable LED torch are available in a variety sizes. There are the cell models which are smaller than a finger, with larger units using arrays of LEDs. Using banks LEDs, the size of a lighting unit can be as large as any common flashlight, with a variety of designs. There was even one which make use a circular field of LEDs for a flashlight torch complete with reflector unit, with a rectangular set on the side but without the reflector unit. This could come in handy when outdoors, replacing portable battery powered fluorescent lights.