The bright light of an LED flashlight can be an invaluable tool when on a camping or hunting trip, and a potential life saver in a home or car emergency. The power and efficiency of these light sources has made them incredibly popular throughout the world. How did these bright lights become so popular? How does the LED bulb in the flashlight actually work? Science and practicality have come together to create these innovative light sources - it may just be a good idea to know why.

What is an LED?
To understand how an LED flashlight works it is important to understand what an LED light is. LED stands for light-emitting diode. It is a semiconductor diode that emits light when an electric current passes through it, like a simple circuit. This circuit produces electroluminescence, which can be infrared, visible, or ultraviolet, and a number of different colors depending on the make up and condition of the semiconducting material used. These lights are often very small, typically less than 1 mm. Manufacturers usually add special optics or lenses to the chip to help with reflection, creating an incredibly powerful beam for the size of the bulb.

LED lights are embedded in a high-impact epoxy, which makes them virtually indestructible and therefore perfect for handheld lights. There are no loose or moving parts either. LED lights also produce no heat, allowing them to be used for long periods of time without concern of burning out.

LED Light Advantages
LED light technology has certain advantages that help it stand out for flashlight and lamp use - visibility, intensity, color and efficiency.

Visibility
LED lights naturally emit a high level of light, called luminous intensity. This visibility is increased by adding chips to the encapsulation or using secondary optics to distribute light. For most LED flashlights or lanterns, there are a number of individual light sources in a single lens.

Intensity
The intensity of the light is another characteristic of LED lights. The light output varies depending on the type of chip and encapsulation that is used. Although there is no industry standard for LED brightness or intensity, many manufacturers use terminology such as "ultra-bright" or "super-bright" to describe their lights. These lights have such a powerful beam that they can actually do damage to the human eye.

Color and Wavelength
Wavelength and color are other characteristics of LED lights. These lights have a pretty broad wavelength spectrum and thus can produce a number of different colors depending on the phosphorous or other compounds added to the encapsulation. The human eye is most responsive, however, to yellow, orange and red LED lights, probably why many come in those colors.

Efficiency
LEDs are solid-state devices with no moving parts. This allows the average LED light to operate for approximately 100,000 hours at relatively normal ambient temperature (25 degrees C). And unlike other incandescent bulbs, they can be turned on and off without undergoing too much wear and tear.

Putting It All Together
The basic construction of an LED flashlight is pretty straightforward. A simple closed circuit is used to charge the semiconductor diode, producing a brilliant, cool light. These lights illuminate our pathway in the dark, help us during power outages and signal for help. They are tremendous assets to a home, car or supply boxes.