Electric Adapter on Lamp Buzzing

[mbenz76]

I have a couple of stand lamps I bought for the house, and they have a large(ish) adapter type plug (big square block that gets warm when used instead of a standard plug) which I assume is converting voltage.

Any way, to cut a long story short, they are perfectly silent, until I turn the mains off to them. Then the adapter buzzes for about 5 seconds before silence again.

Is this something to be concerned about, or just normal sounds? Someone I spoke to said a lot of adapters buzz for a few seconds after switching off, but couldn't tell me why.

Thanks

 

[Steve]

ah wall warts! AKA plug-in transformers.

I wouldn't worry about what you describe. Transformers make all sorts of funny noises. As long as it doesn't sound like your local substation, you will be ok!

 

[mbenz76]

Thanks