Voltage dropping When using 1 supply for arduino(5v) and 1 supply for motors(24v)

Projects General Guidance
1

Hi, I need some help. I'm using two separate power supplies—one 5V for the Arduino and one 24V for the motors. The problem is, whenever the motors start running, the sensor readings for pH, CE, and NTU suddenly drop. I'm not sure what's causing this interference. Any advice would be appreciated!

2

No idea what pH, CE and NTU are. Start by reading the pinned post re 'How to get the best from the forum.
A photo of a hand drawn and labelled wiring diagram is fine.
It is 'normal' for voltage to drop some amount under load.

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3

Welcome to the forum

Do the two power supplies have a common GND connection ?

Please post a schematic of your project showing all of its components, how they are connected and how they are powered. A 'photo of a hand drawn circuit is good enough

4

circuit_image (4)
circuit_image (4)1920×1668 347 KB

6

Yes, it has a common ground.

7

Not in the diagram.

8

Assuming the orange box is the motor, then one of its terminals does appear to be connected to the Arduino GND:

image
image1471×1192 110 KB

9

The buck converter goes to the DC socket, which has a voltage range of 7-12volt.
Anything below 7volt won't give a stable 5volt rail for the processor and sensors.
The "motors" need flyback diodes across.
Leo..

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10

Punkt hydrogen, Chinese Export, Nottingham Trent University.

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11

In your diagram, label the devices and their pins.

12

I would expect some voltage drop across the proto board, the connections are not that good and get worse over time. The fuzzy picture is not much help, an annotated schematic would be great.

13

should the motor ground not connected to the Arduino ground?

14

I have also identified that the relay is causing the voltage drop even if the motors are not connected, when they are activating

15

Post#9
Did you power the DC socket with 5volt?
Leo..

16

My comment was a response to the comment just before mine, which stated that your diagram did not depict a common ground.

17

HI, @thesis_jesa

Do you have a DMM? Digital MultiMeter?

Tom.... :smiley: :+1: :coffee: :australia:

18

Yes

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Please answer all the questions.
Leo..

20

I powered it with a 7 volts DC

21

There's quite some confusion in this thread, with one exception; everyone but you(?) agree that a diagram can fix this confusion, so we can help you forward. You want help, right?