Experiment: 2-Channel Relay Module with Optocoupler Protection for Arduino Expansion Boards
<big>'''[https://www.unikeyic.com/products/1003001445136337/PC817B.html PC817]'''</big>
The optocoupler is extensively utilized in computer terminals, thyristor control devices, measuring instruments, copiers, automatic ticketing systems, and household appliances like fans and heaters for transmitting signals between circuits. It provides complete isolation between the input and the load, enhancing safety, minimizing circuit interference, and simplifying circuit design.