Das Problem mit lauten Kernen und wie man es löst

If you have used soft magnetic cores you will have experienced “noise”, the most common is the hum of transformers in the 50Hz net.

Where does this noise come from? Why is it sometimes negligible? And, why does it sometimes reach an unacceptable level?

In this paper, we explore the causes of noise between two different sources – the noise created by the action of magnetic flux within a soft magnetic core and the noise created by magnetic flux when it is present between or outside the core.