Opto-isolator

An opto-isolator is a device that uses light (optical) to create a barrier between two systems. It does this to stop electricity from one system from going into the other system, like a barrier blocking the electricity from passing. Opto-isolators work by using a LED (light emitting diode) on one side and a photocell (a device that can detect light) on the other side. The LED sends out light to the photocell and the photocell turns it into electricity that can pass through the barrier. Therefore, the opto-isolator can pass signals through the barrier without electricity passing back and forth.