Relay seems to be getting a signal, but no clicking

Projects General Guidance
1

Hi everyone

I'm at a bit of a brick wall at the moment. Ive had a shipment of these relay modules link here but I can't get them to work.

I was using an esp32 with no luck so I just decided to run the blink sketch on an arduino uno to troubleshoot.

DC+ to 5v
DC- to GND
IN to pin13 (built in led etc.)

The green power light comes on, and the red led on the module comes on with the built in arduino led so that suggests it is getting a signal

But there's no clicking to suggest the relay is doing anything. In case I stumbled upon a magic relay that's silent, I've tried hooking up a powered 12v led to NO with no luck , it shines through NC so the LED is not broken

I've tried hooking up DC+ and - to an external power supply and increaased the voltage above 5v in case it wasn't getting enough juice, and I just get a gradual light on the red signal LED which is really weird, I don't know why it's doing that but it shouldn't matter

I've swapped out 5 modules with the same issue now, could it be that I just had bad luck and have bought a batch of faulty relays?

Thanks in advance

2

Is the 5V relay being driven by a 3V3 MCU?

3

The DC+ is connected to the 5v arduino pin

4

did you try an other pin that is not driving the internal LED?

5

This sounds like you are powering the relay board through the Arduino.
This is really bad.
Please post a wiring diagram before going much further.

6

Note: A Power Supply the Arduino is NOT! It only has a few extra mA available and overloading it causes lots of nasty things to happen. I generally use 12V or 24V relays as I power with an external power supply of that voltage.

8

Hi, @milklizard88
this is the schematic of your relay module.
If you have knowledge in electronics you will understand how to connect it and avoid feeding it with +5V coming from the arduino.
The relay coil is 12V so it will be necessary to supply the module with 12V.

ModuloReleX
ModuloReleX1920×623 104 KB

9

But OP posted a link to a 5volt relay module.
And it shouldn't be a problem to power one or even two 5volt relay modules from an Uno.
There must be something else going on, like not setting the pin to OUTPUT.

Posting guidelines tell you how to give us all the needed information.
Wiring diagram, image, and code.
Leo..

10

In the link that the OP posted there are 3 figures,
one with a 5V relay, one with a 12V relay and the third with a 24V relay.
Can't tell which one he has.

@milklizard88 What voltage is written on your relay?