An opto-isolator is an electronic component that transfers electrical signals between two isolated circuits by using light. Opto-isolators prevent high voltages from affecting the system receiving the signal.

Why opto-isolator is used?

Optoisolators are most suited to isolation voltage from digital signals, but they can also be used to transfer analog signals. ... Optoisolator components can also protect Ethernet and fiber optic cables from electrical surges. In VoIP phones, electrical signals can be isolated using a transistor output optocoupler.

Where are opto-isolators used?

Optoisolators are widely used in power supplies, control and monitoring systems, communications, and other systems to safely couple one circuit section to another electrically, while preventing direct contact and high voltages from affecting the lower voltage side.