Hi all, the noise produced by my step down transformer is sometimes annoying. May i have some knowledge regarding why the transformer producing noise when i use it for isolation purpose in dc-dc converter?

 

The changing magnetic field makes the iron vibrate.

 

Noise is produced by something moving, especially if you have say E and I laminations in the core. A solid toroidal core typically makes less noise, but then even the windings may vibrate.

You may try coating the entire transformer in varnish to "glue" things together. There are special grades made just for this, usually the entire assembly is dunked then put in a vacuum bomb chamber.

 

Noise is produced by something moving, especially if you have say E and I laminations in the core. A solid toroidal core typically makes less noise, but then even the windings may vibrate.

You may try coating the entire transformer in varnish to "glue" things together. There are special grades made just for this, usually the entire assembly is dunked then put in a vacuum bomb chamber.

Oh means the noise cant be avoided in high frequency application, but we can do something like coating transformer in varnish so that the core and winding can hardly vibrate and hence will not produce any sound.

 

Sometimes a lamination will become loose which greatly increases the noise, giving a loud buzz type of sound.

 

Yeah what I am using for making the transformer is this type of E core kit.