5V 2 Channel 5V Relay Module with Optocoupler Low Level Trigger Expansion Board Compatible with R3 MEGA 2560 1280 DSP ARM PIC AVR STM32 Raspberry Pi (2channel-4pc)

Works as expected, and at four for $10 seems like a solid deal for hobby or prototyping work. And this module can be triggered from 3.3V boards like the Particle Photon as long as you have 5V to power the module.There are a couple key details here. One is that the relay actuates when the control line (IN1 or IN2) goes low, so you just need to sink a few mA to ground through the micro, not drive a particular voltage. The other is that the control inputs (IN1 and IN2) float at around 3.1V even when VCC is at 5V, making them safe to connect to a 3.3V microcontroller sharing common ground with the 5V supply. An example setup with the Photon would be feeding the microcontroller board with a USB power supply and then using the VIN pin (~5V) to feed the relay module.Some testing with a variable supply and a multimeter showed the following:With JD-VCC at 5V and the control input grounded, the relay would reliably pull in when VCC passed 3.2V, and drop when it fell below 3.0V. This suggests the board would probably work ok pulling the JD-VCC jumper and running the logic side at 3.3V, but at a pretty thin margin.With VCC at 3.3V and the relay pulled in, the control input was sinking 0.5mA to ground. With VCC at 5V, the control input ran about 2mA. These current levels are no problem for Arduino and Photon.The current draw on JD-VCC (set at 5V), it was around 40mA with a relay pulled in (VCC at ~3.2V) and around 15mA when it dropped (VCC ~3.0V). With VCC at 5V the draw on JD-VCC was around 65mA.If both VCC and JD-VCC are fed with 5V (i.e., jumper in place), the total draw was around 90mA with one relay pulled in.I repeated these tests with IN1 and IN2 on one particular module, and found the behavior to be consistent. I did not test multiple modules.

Works like they should, easy to hookup. I am happy with the purchase. Value us good considering delivery cost.

I grabbed these for a project where I couldn't use a small solid state relay board. I had a few of these with 8 relays on them but didn't need that many. It was great to get a 4 pack since I had spares for the bench. Did the trick with no surprises.

These relays are perfect for a Raspberry Pi thermostat I'm building. A very good deal for the price, excellent quality, and very fast delivery.

Two of the 4 worked great, two others had 1 disfunctional relay out of the pair.One had a totally damaged trace, not sure what is wrong with the other.

Fit my needs perfectly

Nice relays. Of the two I have tested, both function properly. Price is right.

Poorly packed, bottom layer peeling. Bent pins. Otherwise, the one I've tested so far appears to be functional

Works fine, but is active LOW. So just be careful, you need to set input to ground to activate the relay

very good product, good price, buy with confidence

Good