Although an opto-coupler or opto-isolatoris usually thought of as a single integrated package, it is possible to achieve the same result using separate devices. They use light to pass signals between circuits. As we have already learnt about transistors, an ideal transistor will not. Optocouplers, also known as opto-isolators, uses infrared light to transfer electrical signals between two electrically isolated circuits and are commonly classified by their photosensitive output device What is an Optocoupler? An optocoupler (also called an opto-isolator, photo-coupler, or optical. An optocoupler (or opto-isolator) is a component that transfer signals between circuits using light. In this guide, you'll learn how they work and how you can use one in your own projects. Optocouplers are very useful when you need to isolate different sections of a circuit, for example in power. An opto-isolator (also called an optocoupler, photocoupler, or optical 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. This small non-monolithic device does one thing and does it well, with minimal complications in most cases and no software.