What is an LED?

Light Emitting Diode

A diode is a solid-state semiconductor component that allows electrical current to flow in only one direction.  In the case of a light emitting diode (LED), the component emits light while it is energized.

LED schematic.

 

White LED Light

There are a couple of ways that LEDs generate a white light.  Phosphor conversion in which the LED chip emits blue or near ultraviolet light. The LED chip is coated with phosphor, which interacts with the emitted light to produce white light. This is like the way that light is generated by a fluorescent lamp, and is the more common and cost effective type of white LED.

RGB (Red, Green, Blue), or color mixing, systems combine the light output from three or four monochromatic LEDs (amber can also be used to increase the color palette) in order to produce many different colors of light, including a full scale of white light hues which are measured by their respective Correlated Color Temperatures (CCT).