12v 8 channel relay module & 5v arduino

[techgrief]

Hello.

I have a question about buying an 8 channel relay module. I would like to operate the relays with a 12v power supply and switch the relays on/off with my Arduino (5v). Since it's just a hobby project I don't want to pay too much for it and so I want to buy one from Aliexpress (so please don't suggest Amazon or something).
The relay module I have been looking at ( https://www.aliexpress.us/item/3256802681413225.html ) has a separate connector for a power supply, so I want to connect a 12v one. But if I buy the 12v module, will I still be able to control it with the 5v of the aruino via vcc, gnd and in[1-8] (at the main header...) while the 12v power supply is connected to the relays? The picture should make it easier to see what I mean.
Thanks for any help

[alto777]

That will work if it works.

I mean it is designed to use the Vcc of your Arduino for the control part, and the other power supply, 12 volts here, for actually moving the relays.

It should work with 5 volt system.

To be safe, when you get the module hook up the 12 and 5 volt supplies of voltage (power and ground red and black), but do not connect the relay control pins.

Instead, use a jump and shirt one control input to ground, then to Vcc (5 volts) alternately.

You might see a LED go on and off, you shoukd def hear the corresponding relay click as it is energized and not energized alternately.

Then you ready to rock and roll.

Be sure your 12 vo,t supply is sufficient to power as many relays as you plan to have energized at the same time.

Best: use 12 volts with enough power for all eight at once and code with no particular constraints around how many. Sleep better at night.

a7

[david_2018]

Usually the Vcc / JD-Vcc jumper would be removed, and the 12V supply for the relays would be connected to the GND and JD-Vcc pins of the 3-pin header, with Vcc left unconnected.

The Arduino 5V line would go to Vcc of the 10-pin connector, with the individual relay control pins being connected to output pins on the Arduino. The GND pin should be left unconnected.

Testing as suggested by @alto777 should activate the relay when the relay control pin is connected to GND on the Arduino.

[techgrief]

Thank you very much for the detailed response. I will be ordering one now and will be going to do exactly what you told me.

[LarryD]

8 channel 12V relay module.

[alto777]

@techgrief

exactly what you told me.

Haha, not quite:

@alto777

use a jump and shirt one control input to ground

Use a jumper to short one control input…

@david_2018 and @LarryD have supplied additional information and clarification.

Let us know how it goes.

a7