4 channel relay not behaving as expected

[milklizard88]

Edit, this problem is solved, i needed to connect the vcc to my arduino 5v, not just 12v to the JD VCC

Hi, see this picture below, the module wont behave in the way i expected it to. The only way i can get the relays to engage and an indicator LED is to connect vcc to 12v, gnd to gnd then bridge the IN pins to ground as shown.

If i try and pull out the jd vcc jumper, that kills anything and i cant make the relay engage.

When i use a separate power supply with 5v, it doesnt work either. I even tried bumping that voltate to 12v just to see, but no change, still only engaging when i bridge the gnd and IN pins

If i pull out the blue jumper thing between JD VCC abd VCC and connect up as before i get only the indicator light when i ground the IN pins, i dont get the relay clicking.

Do i really need 12v to activate the signal pins? I thought the whole idea of them is that they can be triggered by a microcontroller (currently using an esp32)

[hammy]

You need 12v to energise the relay . If you google Arduino relay board , you will get to see how to wire it up.

Never just try things , research it or you can easily damage the Arduino

[milklizard88]

Thanks for the reply, as you can see in the pic I had already done as you suggested, connected VCC to 12v on my power supply, but the relays were not being triggered by the signals from my microcontroller, that is my problem

[LarryD]

These relay boards are LOW true.

Try this wiring setup:

@dlloyd
The relay coils on your board are 12v.

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[milklizard88]

This solved the problem, i did not connect VCC to my arduino 5v so it was not being triggered. Thank you for your suggestion

[michael_x]

@LarryD

The relay coils on your board are 12v.

I understand SRD-05VDC-SL-C are activated by 5V. They might survive 12V at JD-VCC but that's not guaranteed.
12V at VCC might even kill your ESP signal pins, not only the relais coil.

[LarryD]

The OPs relay coils are 12v.

The ESP 5v to relay module Vcc is used on the opto isolator input side.

(5v - (2 LED drops)) / opto resistor = opto current to ESP output pin.

I’d prefer to add a NPN between the ESP outputs to relay board input terminals.