DC 5V Relay Module 1-Channel Relay Switch with Optocoupler Isolation High/Low Level Trigger, Pack of 10

It's well thought out. It's easy to control the relay from a low power processor pin - just a couple mA will do the job. You can select whether the relay is triggered by a Vcc or ground signal, and the relay itself is SPDT. It works fine at 5v.The board has a power LED, which is annoying because power drain is an issue with battery circuits, and a separate LED which lights when the relay is energized, which is more acceptable. They can be removed.The relay itself is small and won't switch high currents at high voltages, but you can easily use it to control small lights, little motors or a larger relay.Pleased.

I bought this accidentally, but it's a great purchase nonetheless. I've used only one so far, and it works fine.

Well documented above, rare for such DIY parts. No soldering required (for those who don't like that).Very versatile, you can reverse the input logic with the jumper. I also like that the output terminal provide both NO (Normally Open) and NC (Normally closed) so it can adapt to your application when you lose power to the boards with NO or NC. I find the green power LED very bright. I might remove it from the board. The red LED is just bright enough in my opinion. Very well packaged, individually wrapped, they look like candies!Works well driving and powering the relay with a Wemos D1 mini with the D6 pin (digital 6). I have flashed the Wemos with Tasmota.WOULD BE A KILLER BOARD IF: it was combined with a transformer and regulator so it could produce 5V from the OUTPUT lines. I mean I'm mostly driving 120V on the relay output side. If the board could take Line+Neutral, then you could power the relay board and the Wemos micro without an external power supply. Essentially, creating a smaller Sonoff.Martin Politick January 2020.

Works great, simple to use. I use NO and NC sides. I have not run more than about 5 amps through them. For the price they cannot be beat.

As a hobby project I have been using these relays to build smart extension cords controlled by ESP8266 chips, and for the most part they have worked quite well, but this morning I discovered one was no longer stopping current flow when the relay was turned off. After investigating I found the NO and COM terminals had melted together due to heating, see the first picture.This relay was being used to control a 1500W space heater and I do not have solid data on runtime, but I would estimate it worked for roughly 30 hours, so if you are powering something lesser I would not be too concerned. However after enough time with such a significant load the terminals have failed completed.On the upside, I ripped the terminal block off the end and tested the relay itself to verify it was still working!If you are looking to control something so powerful, maybe look at just getting this type relay without an accompanying board and put your own circuitry in front of the control side, but at $1.5 for these versus around $0.8 for just the relay, which would require additional effort to put circuitry in front of the control side, this is a pretty solid purchase, and you could always just bypass the terminal to connect your wires to the relay's contacts directly. I intend to do exactly that with the pictured relay and put it back to work!

These work great for use with the arduino since you can grab the 5V on board the unit to power it up. Using the 3.3V for power will not pick these relays so you have to use the 5V but other then that they are great relays and can run up to 10 amps which is great for certain projects.

Works well, easy to use, HC-SR501 PIR Motion Sensor will drive relay directly (no arduino, no transistor, no optocoupler)

I built a lot boffins Halloween props. They work great with PIR devices to set off electronic triggers for the animated props.

The input isolation is confidence-inspiring. The reversible activation logic is a great feature, although it means you need 5V power to the relay at all times. Worked flawlessly with Raspberry Pi GPIO.The documentation could definitely be better though... the Amazon product page gi es yiu all the connection diagrams, although I would have preferred some printed sheet with the relay itself.

Works as expected

Works fine for what i need. The HI/LO jumper is what i need for my project

Nice little realy

Juste essayé un pour voir, il fonctionne.