AITRIP 8 Pack 3V 1 Channel Relay Power Switch Module with Optocoupler Opto Isolation High Level Trigger for IOT ESP8266 Development Board

So far they are working while being driven from a single pin from my ESP8266 development board. The connectors for the load wiring are a bit small for what they are supposedly rated for. More like standard hookup wire size. I have found one so far that had it's board corner broken, no good for mounting, but still works. Worth trying at the price, I have yet to see how many cycles they will run on my project.

All 8 modules checked out without any issues. It is nice having the straight 3.3V interface without having to adapt it to other circuits. This pairs very well with STM32 and RPi Pico boards right out of the box.Overall component temperature and relay holding torque seem to remain very good even after months of repeated use.

these work as expected. the jumpers don't seem to do what the desc says, but if you just leave them on as they come out of the package the part works as you'd expect & isolates between the HV and LV sides

Just putting my prototype together with a ESP32 WROOM-32 DevKit. I wanted to know what the jumpers did and the schematic for this relay module, so I had to reverse engineer it. Hope you find this helpful.

I wanted to use these in an application powered by a Li-Ion battery (so the voltage wouldn't be well regulated). Bench testing with an adjustable power supply and mid-range voltmeter showed that these worked reliably on my bench as low as 2.92V and when I ran them at 4.4V for an hour, no ill effects were noted. So, these should work pretty well for the range of voltages provided by a 1S Li-Ion battery.(They naturally will work fine as intended from a regulated 3.3V source.)If you want to get a jump on designing the mount/enclosure, my units measured:17mm x 70mm - PCBYou need 2.5mm under the PCB to allow for the through-hole components.I'd allow at least 18mm from bottom of PCB to top of relay, but 19 or 20mm would be better.The holes are clearanced for M2.5 screws and are 66mm on center long-wise, 12.8mm short-wise on the input, and 13.0mm on the output. (I'm not sure how much of that is intentional vs a slight deviation.)Spacing for the input/output terminals are 5mm center-to-center between terminals and 50mm center-to-center between input and output.