Buck converter is making noise

I am working on a project where mains voltage is first converted to 12 v and then it is converted to 5v for the arduino by a Buck converter. However, this Buck converter makes a weird sizing sound as soon as I connect the arduino.

My question: Is this normal or shouldn't it be? If this doesn't work out, how can I fix it?

It concerns the DSN-Mini-360

Usually it's normal a d won't hurt. It can be annoying through.

Is there a way to stop it?

Yep, change the load, apply some kind of sealant/glue to the inductor or pick another kind of DC-DC converter.

It’s just possible there is some interaction between the two power supplies - are capacitors on the output recommended ans fitted ?

It's probably the inductor resonating the PCB - higher frequency switching supplies tend to be less audible, although some drop frequency into the audio range when lightly loaded.

This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.