High frequency Humms when fan connected

Other Hardware Audio
1

Hi everyone ,
I have an audio system with mp3 module, an amplifier, speaker and fan for cooling the cabient.
the fan create a lot of noise that sound in the speaker as high frequency humms. any ideas for reduecing this humms ?

thanks ,
yinon

2

you posted in the "using Arduino" forum. where is the Arduino? You didn't post more than a few words about it. please follow the forum rules and post proper information.

3

Post a schematic of your system, not a frizzy picture and links to "Technical" information on the hardware.

4

A valve amp?

5

Hi,
Please post some images of your project so we can see your component layout.

What sort of fans are you using?
What is their power supply?
Have you got the fan wiring well away from the other audio signal wiring?

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

6

European name for a vacuum tube.

7

From what information you have given I suggest to simply turn the fan off and do not run it so long. If that is not satisfactory then give us information to work with. By the way if the hum does not go away when the fan is off I suggest it is from your amplifier and it would need to be shielded from the MP3 player.

8

hi ,

i am using 12v fan with 12v amp module :

[https://www.kemo-electronic.de/en/Light-Sound/Amplifier-Splitter/Modules/M033N-Amplifier-18-W-universal.php](https://Audio 18W Amp)

and mp3 player module controlled with my own board (based on NanoEvery) :
https://www.dfrobot.com/product-1741.html

the breadboard setup :

20221018_162007
20221018_1620071920×1440 340 KB

20221018_161955
20221018_1619551920×1440 258 KB

the final board :

20221018_160837
20221018_1608371920×2560 419 KB

20221018_160819
20221018_1608191920×2560 352 KB

9

Have you tried different types of 12 volt fans? What do you consider "high frequency"?
Add long wires to the fan and move it far away to see if the "hum" level is reduced.

10

Hi,
Is that your PCB design?
If so can you post exported jpg images of both sides from the CAD you used.

Have you used ground plains and considered current flow through your PCB.
A schematic would also help.

Thanks .. Tom... :smiley: :+1: :coffee: :australia:
PS. If you connect the fans directly to their power supply terminals, does the noise disappear?
That is make sure that there is NO fan current flowing on your PCB.

11

It's not so simple to replace the fan everything should be mount on a metal palete with cnc millling. we talking about a small, water proof cabient so everyting is really tight inside.

12

The fan is connected directly to the main voltage , parallel to the board.

13

Hi,

At this point, forget about size etc, you need to troubleshoot your project first and get it working properly.

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
Hand drawn and photographed is perfectly acceptable.
Please include ALL hardware, component names and pin labels along with power supplies.

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

14

Hi,

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

15

yeah, amps and limited analog will always makes stupidness on project

16

give us a fritzing/tinkercad, we cant see connection that good on camera (just leave non existing modules as blank(only connect their pins) we'll understand theres a module here

17

Lead dress could be your problem. Are all low level signals in shielded cable, if not try that. Also your fan has a coil which is also an antenna, try different positions and orientations to see if that helps.

18

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