It provides excellent electrical isolation (typically 2,500-5,000V) between input and output, making it perfect for protecting sensitive microcontrollers from high-voltage circuits, but it cannot directly drive solenoids, motors, contactors, or anything requiring more than 50mA. As an isolator, an optocoupler can prevent high voltages from affecting the side of the circuit receiving the signal. Transferring signals over a light. There should be some protection against reverse polarization, transient over-voltage and permanent over voltage (up to 40V) to some degree. One. Optocouplers and alternative isolation technologies find widespread use in a variety of products for signal isolation and high voltage level shifting.