Single 12V power for Nano, Relay and its Load

Other Hardware Motors, Mechanics, Power and CNC
1

power v2d_bb
power v2d_bb1920×1340 206 KB

Hi,

Could someone help to check if my scheme is correct.

I can't find a schematic diagram to understand if common power supply and grounding is possible.

DOC015130159
DOC015130159543×746 126 KB

The diagram is simplified as much as possible for understanding.

I am concerned about power supply from a single 12V power source, as well as grounding:

  1. Arduino Nano to Pin Vin 12V
  2. Relay 12V
  3. Fan load 12V

Thanks everyone anyway!

P.S. I have seen a few circuits where the power and ground were also shared, but there is no feedback on whether they worked/

For example:

Circuit-3
Circuit-31536×1536 310 KB

Skhema_pozharnoj_signalizacii
Skhema_pozharnoj_signalizacii955×511 101 KB

2

In the first picture the controller is powered by 12 volt to Vin. That might be okey.

Feeding 4 relay coils from the controller 5 volt pin is bad design, maybe even very bad and overheating the onboatd 5 volt converter.

3

Yes, that's right, it's my mistake, I already updated the schematic.
Just removed 5V from Nano to VCC relay.
But I'm not sure what is needed to activate the relay, ground and signal?

I still haven't found the original schematic for the relay.

I found only two schematics, and both are controlled differently:

4_channel_relay_schematic_VCC
4_channel_relay_schematic_VCC800×954 130 KB

4_channel_relay_schematic_Ground
4_channel_relay_schematic_Ground1169×827 72.6 KB

4

Are the relays activated by a LOW or HIGH signal from Nano?

5

There is no information about this.

I just ordered this relay and it seems I will not receive the datasheet for it.

When I receive the relay, I will try to find out. Or, hopefully, I will find the relay diagram.

6

It's still wrong.
You must remove the Vcc-JD jumper
You need to connect Vcc to 5V from the Nano

The first schenatic is the one for your board.

7

JD-VCC jumper opened. On the Fritzing no way to remove jumper, I’ll erase it in photoshop, and update first scheme.

What about 5V Vcc from NANO:

8

It won't work without it.
Don't know what @Railroader is referring to, something you changed on the schematic maybe?

9

Yeap, my first version was with 5V power from Nano to Relay Vcc

10

Connect a jumper wire from Arduino 5V pin to Vcc pin on relay, connect a jumper wire to Arduino GND, touch the free end to IN3. Did relay 3 activate?

11

That is correct!
Won't work witout it

12

OK. thanks

13

The first schematic you show is the one for your board, so relay are active LOW

14

As I wrote before, I don’t have the Relay for now, I’m waiting its delivery.

Thank you.

=========

And what about the fact that Nano, Relay and load relays are powered from one 12V source, and all together are grounded.
Shouldn't we expect problems?

15

You would expect problems if all the grounds were not connected.

I have no idea what you are doing with the 24V volt supply but it doesn't affect the Nano or any of the 12V connections.

16

So, your "schematic" does not represent the actual components. It's just a montage of generic pictures?

17

What about the heat in the 12 to 5 volt onboard converter when 4x relay coils draw current? Without a relay current spec it looks dangerous using the board as power supply regarding 12 volt Vin.

18

They are powered by the 12V connected to JD, not from the 5V connected to Vcc

19

24V power supply for the audio amplifier, the amplifier in turn powers the RPI4, the relay initiates software shutdown of the RPI4, then turns off the 24V power supply.

All components are real, but not all I’ve received.
And no wires for powering the RPI4 from DAC 24V.

P.S. First scheme updated. Added power 5V from Nano to Relay VCC. Cleared jumper JD-VCC on Relay

20

I'll take you word for it about that part but everything else is OK.