A light-emitting diode (LED) is a two-lead semiconductor light source. It is a pn-junction diode, which emits light when activated.
They are very useful for workbenches, lighting building projects, and even directly on power tools because they use little power and emit a strong and stable light source.
That’s what you want when lighting a project, light that doesn’t flicker and can easily be powered, from a battery or the tool itself even.
When a suitable voltage is applied to the leads, electrons can recombine with electron holes within the device, releasing energy in the form of photons.
This effect is called electroluminescence, and the color of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor.
An LED is often small in area (less than 1 mm2) and integrated optical components may be used to shape its radiation pattern.
Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared light.
Infrared LEDs are still frequently used as transmitting elements in remote-control circuits, such as those in remote controls for a wide variety of consumer electronics.
The first visible-light LEDs were also of low intensity, and limited to red. Modern LEDs are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.
Early LEDs were often used as indicator lamps for electronic devices, replacing small incandescent bulbs.
They were soon packaged into numeric readouts in the form of seven-segment displays, and were commonly seen in digital clocks.
Recent developments in LEDs permit them to be used in environmental and task lighting.
LEDs have many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching.
Light-emitting diodes are now used in applications as diverse as aviation lighting, automotive headlamps, advertising, general lighting, traffic signals, and camera flashes.
However, LEDs powerful enough for room lighting are still relatively expensive, and require more precise current and heat management than compact fluorescent lamp sources of comparable output.
LEDs have allowed new text, video displays, and sensors to be developed, while their high switching rates are also useful in advanced communications technology.
I'm Joost Nusselder, the founder of Tools Doctor, content marketer, and dad. I love trying out new equipment, and together with my team I've been creating in-depth blog articles since 2016 to help loyal readers with tools & crafting tips.