Powering 8 Channel Relay Module

Other Hardware General Electronics
1

Hi!

I'm new-ish to arduino. I have a background in computer science/programming but not so much in circuitry and electronics past high school physics class...

Anyway, I'm trying to control 4 outlets with my arduino UNO and this relay module: https://www.amazon.com/gp/product/B01NBUDHPB/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

I've wired up the outlets, connected one to one of the relays and successfully tested it out using the 5V power straight from the arduino.

But, from what I understand, power straight from the arduino is enough to power one of the relays but not all 8. Before connect the other relays to outlets and my arduino, could someone describe to me exactly how I should power the relay board?

2

Use an external power supply for relay supply.

Relay card X8.jpg
Relay card X8.jpg1402×836 210 KB

from ddloyd

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3

So will it really be as simple as connecting the power supply to the JD-VCC and GND on the relay? Does the Arduino 5V still go into the relay as well?

4

Arduino +5V goes to the opto coupler input side of the cct. 'not' the relay side.

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5

By opto coupler side, do you mean the header with all the IN pins as shown in your diagram?
Also, my relay module has the VCC & JD-VCC already connected... would that be an issue?

6

spencercc:
By opto coupler side, do you mean the header with all the IN pins as shown in your diagram?
Also, my relay module has the VCC & JD-VCC already connected... would that be an issue?

The 'IN' pin is the optocoupler input side.

Remove the connection between VCC & JD-VCC, as covered in the drawings.
This enables proper isolation.

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7

Alright, I think I got it. Thank you very much for the help, larryd!