Audio range switching frequency

[AlienCircuits]

I am finding I don't have much of a choice in the switching frequency for my buck converter, and choosing a frequency in the audio range makes things a lot easier for the design. My concern is how to know how much audible sound this choice will result in? My understanding is that the mechanical vibrations are from the coils of the inductor moving from the changing magnetic field. Is that accurate and isn't this dependent on how much current I'm passing through the inductor and how well constructed the inductor is mechanically?

 

[FvM]

Audible noise from inductors/transformers can be reduced by fixing coil and core thoroughly, possibly moulding it. But all ferromagnetic cores have a certain amount of magnetostriction, depending on core material and peak flux. It generates sound of 2nd harmonic for symmetrical magnetization and in addition of fundamental for DC flux.

In so far, no audio range switcher will be absolutely silent.

 

[jeffrey samuel]

even though the vibrations are bit of concern but the net effect is very low if the core is aligned the right way otherwise there will be a lot of noise

in real time there is no device without noise

 

[AlienCircuits]

Thanks for the replies :grin: