2PCS 4 Channel 5V Relay Module with Optocoupler High or Low Level Trigger Expansion Board for Raspberry Pi Arduino

Great 4 channel relay module for Arduino & Raspberry Pi. Includes a 5V in and ground screw terminal pair (marked as DC+ and DC-, respectively), along with four inputs for each channel. The relays all have optocouplers, transistors, flyback diodes, and LED indicators, so you don’t need to worry about adding those yourself. The opposite side of the board has Normally Closed, Common, and Normally Open connectors (marked as NC, COM, and NO respectively) for each relay.

Reliably switching 24v sprinkler solenoid valves for over a year. Good price! Got a backup... It's in an outdoor enclosure so I don't care about the noise (yes, it's a mechanical relay) or the LED (nice visual feedback). Easy to integrate with an Arduino and I think it'll do just fine. The system doesn’t stay out in the winter but it's there during the 100°+ heat. I have not experienced any negative issues with the Arduino and I assume it's optically isolated to the controller/signal.

Works as expected, I previously got the 12.0 volt version by mistake but was still able to get it to work with an extra power supply and connecting the grounds, but with the 5.0 volt version I was able to I was able to remove the added power supply and just swap in the same connections.

Works as expected so far. One had some superficial damage to the jumpers, the other had a large gob of solder connecting the rightmost diode to the ground plane, so much so that it looked like someone sculpted the letter "Y" with it. I hit it with a bit of solder wick and it seems to function fine. Not a problem for me, but it would have possibly disabled the 4th relay for someone that didn't have the right tools to fix it.

Great little relays board if you dont want to do it yourself

one ⭐ review: wrote a basic HIGH LOW program to cycle through relays all relay function except the damaged one. up date Feb 3, 2023 2:12 AM: contacted ANMBEST about damaged relay they responded promptly and resolved the problem with a refund. updating to ⭐⭐⭐⭐⭐ for customer service.

I use these on a Tram that goes up and down a steep slope. The relay board on the winch end is for up, down, fast and slow speed control. The relay board on the tram end is for steering via a linear actuator and for leveling the tram via another set of linear actuators. These relays are activated by arduino boards and activate larger high current relays. They are also easy to troubleshoot because each relay on the board has an led that lights up when relay is active. I have been using these for a year with no problems and considering the low price are a great investment.

They are what they are at a great price