Optical switches use light as the medium for switching, using a light source for switching interface operation. They are safe and reliable, as no high voltage or current is used when initiating a switch event. Optical switches are of two types – transmissive and phototransistor output.
In a transmissive optical switch, light is passed through a UV-sensitive window. A UV-ridden resistor then disrupts the electric circuit, and the switch activates. These switches are reliable, compact, and low cost.
In a phototransistor output optical switch, light is directed towards a phototransistor integrated circuit. This creates current flow and triggers the switch. This kind of optical switch offers greater flexibility in operation and also greater sensitivity.