Externally powering a 5v - 4 channel relay without a JD-VCC

Other Hardware Motors, Mechanics, Power and CNC
1

Hey there, a noobie in electronics here.
I'm using Arduino Uno R3 and want to have it control 4 12V Pumps, by using a 4channel 5V relay module. From what I've read, I should power the relay externally due to its high current demand. For my module, there is no JD-VCC pin to externally power it with a 5V-1.5A power supply I have. So here I am asking for a way to make this work.
The relay module I have is 4 Channel Relay Module with light coupling 5V red board, and the listed features are these:

    1. Max Load: 250VAC 10A/ 30VDC 10A
    1. SMD optocoupler isolation, driving ability, stable performance; trigger current 5mA
    1. Each channel module can be set high or low-level triggered by jumper
    1. Power indicator (green), 4 Relay status indicator (red)
    1. Board size: 73mm x 50mm x 18.5mm
    1. When com with low short circuit, triggering the corresponding relay is low, and high when com shorted

Is a configuration where I will have:

  • 12V power supply + to COM

  • 12V power supply - to Pump's -

  • NO from relay to Pump's +

  • Digital I/O Pin 2 from arduino to IN1

  • Digital I/O Pin 3 from arduino to IN2

  • Digital I/O Pin 4 from arduino to IN3

  • Digital I/O Pin 5 from arduino to IN4

  • External 5V to relay DC+

  • External GND to relay DC-
    viable?
    Do I also need a common GND between Arduino and the 5V external power supply?
    Thank you in advance!

2

Yes

2 Likes
3

No.

If there is a need for opto isolation, then you must not share power/ground for the relay coils with Arduino power/ground. It would have been better if you had posted a link to the relay board, and a wiring diagram.
Leo..

1 Like
4

Since two good people are not reading this the same post an annotated schematic and include links to each of the hardware items be sure the links give technical information. There many variations of what you describe, we do not know which one.

5

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