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

Well made and useful

These relays worked great for several RPi projects. I can switch the relay straight from the 3.3v GPIO.

Since these are cheaper than optocoupled modules, I will give the benefit of the doubt in the incorrect information in seller's item title. There is NO optocoupled transistor on these boards. The seller appears not to know the various ways and levels of protection to the input microcontroller some with and some without an optocoupled transistor. I highly recommend novices search "Connecting a Relay Module to a Microcontroller" for a good explanation of three different ways. See the attached circuit diagram for the modules being offered by this seller. I rated 4 stars because they happen to suit my particular application well without optocoupling.

These relays did the job for me. I used them with another 4ch Alexa connected relay set to do the function of 2 DPDT reversing switches. It works fine. They are rated for 10 amps but with the very small current loads I have they should last for ever.

Finally, I have a high power relay that can be driven directly from a 3.3v I/O pin without any need for other supply voltages. I only tried one, but it worked just fine switching 12Vdc loads completely isolated. One reviewer that said these are solid state relays is flat our wrong. These are true hard contact relays that operate at 3v. Very nice find.

Bought new LED lights for Christmas tree, and wife complained they don't blink, so I used this to drive 100v christmas tree lights in various flashing patterns. Works perfectly.

Very marginal at 3V, it needs closer to 4V.It would not be reliable driven off 3.3V

Love these little modules. They are reliable and simple to hook up. I use them for irrigation control with 24VAC. Works great.