What is an optical coupler?

What is an optical coupler?

Optical coupler also known as photoelectric isolator,referred to as optocoupler. Optical couplers use light as a medium to propagate the Telecom number.The light emitting diode and the photosensitive transistor inside the optocoupler only convert the voltage or current change of the front and rear stages into light changes,and there is no electrical connection between them,therefore,it can effectively cut off the potential connection between circuits and achieve reliable isolation between circuits.The pin of the light source is the input terminal,and the pin of the light receiving device is the output terminal.The light intensity of the optical coupler is determined by the magnitude of the excitation current,and the light intensity is applied to the light receiving device which is packaged together,because of the photoelectric effect,the photoelectric current is generated,which is led out by the output end of the light receiving device,so that the conversion of the electric light and electricity is realized. 

There are many kinds of optical couplers.Figure 9-3 shows the shape of the optical coupler.The common light source is the light emitting diode,and the light receiver is the photodiode,photosensitive transistor,etc.