Reducing PWM motor noise

Hi there!

When Im driving a fan via a BC639 on PWM it works just fine but on lower analogWrites the fan gets quite noisy.

Are there any techniques to reduce this noise on lower speeds at least a bit?

Thank you very much!

Use a higher frequency of PWM? Checkout things like the TimerOne library for convenient functions to help with this, or read the datasheet chapters on the timers.

Had a similar problem with THIS PROJECT.

The code is there so you can see the approach I took.