The working principle of the LED light bulb

LED light bulbs are essentially different from traditional incandescent lamps in both structure and light-emitting principle. Diode is a common component in electronic circuits. It is made of semiconductor pn junction, electrode lead and tube shell. Diode has two electrodes of PN junction, so it is called diode. The diode has single conductivity. There are many kinds of LED light bulb, such as detector tube, rectifier tube, voltage stabilizing tube, switch tube, damping diode, light-emitting tube, photocell, etc.

LED light bulb is usually made of semiconductor materials such as gallium arsenide and gallium phosphide. It will emit light when passing forward current. The color of light depends on the material used, and can emit red, yellow, green and infrared light. Light emitting diodes are generally encapsulated in transparent plastic. The long pin is the positive pole and the short pin is the negative pole. Some LED light bulbs have three lead out pins, which can emit two colors of light according to the pin voltage.