Optocoupler is a branch of the integrated chip, also known as photoisolator or photocoupler, which is a device that transmits electrical signals through the medium of light, usually the light emitting device (infrared light emitting diode LED) and the light receiving device (photosensitive semiconductor tube, photoresistor) are packaged in the same tube.
When the input end adds an electrical signal, the light emitter emits light, and the light receiver receives the light and generates photocurrent, which flows out from the output end, thus realizing the \"electric-optic-electric\" control.
The optocoupler, which uses light as the medium to couple the input signal to the output signal, has been widely used in digital circuits because of its advantages of small size, long life, no contact, strong anti-interference ability, insulation between output and input, and unidirectional signal transmission.