Review on 🔌 Onyehn Channel Optocoupler Isolated Control: Ensuring Safe and Reliable Signal Transmission by Andre Belitz

I've had this running for months with no problems. I am using it to remotely control the opening and closing of a chicken coop door via a Raspberry PI. It stays active as long as there is a signal coming from the gpio pin on the Pi to the "in" connector. VCC In and GND are the side of the Pi (which gives the commands). NC, COMM and NO are for the regulated circuit. "NC normally closed" "NO normally open" and communication is where the power supply is switched. To have power only when "IN" is triggered, connect the target device to "NO". To cut power to the target device when "IN" is triggered, connect the target to "NC". Update 5:/6/2020 a year later the relays I'm using still work fine, they have BSTEP mechanical relays powered by the 3.3V line on my Pi. Two modules have mechanical "songle" relays. They require more current to operate and their coils require an external power supply. With the exception of the brand, markings and designations are the same. Jumpers on the board connect the VCC and ground terminals to the relay. By removing the jumpers, a separate power supply can be connected to the pins closest to the relay, optically isolating the trigger source from the power supply. (This renders the VCC screw terminal useless, you are still using the trigger + the ground screw terminal for the trigger).