The OptoCoupler is an optical isolator which provides electrical isolation between an input source and the output load. It achieves this by interconnecting two separate electrical circuits by means of a light sensitive optical interface using a device known as a photo coupler.
When the current flowing through the OptoCoupler LED is interrupted, the infra-red emitted light is cut-off, causing the photo-transistor to cease conducting. In this way the photo-transistor can be used to switch current in the output circuit.
The OptoCoupler is a useful electronic device which allows devices to be controlled from a digital switch, low voltage data signal or from a PC’s output port.
The main advantage of the Opto-couple is its high electrical isolation between the input and output terminals allowing relatively small digital signals to safely control much large AC voltages, currents and power.