"Whistling" A/C adapter safe?

[Taffycat]

I have a Creative AC adapter (this one) which re-charges my Zen MP3 player. Today, I'm noticing that it gives off a very high frequency "whistle" (the adapter part, that is, which is plugged into a wall socket.)

It is not that loud, so not annoying, but as I've not noticed it before, I just wondered whether there are likely to be any safety issues? It has not received a lot of wear or tear, so it is in pretty much the same condition as new; also it makes no difference if it is plugged into a different socket.

Hmmm... now that I think about it, we get the same sound when the electric recliner chairs are plugged-in, using their power adapters. They have always done that since new. So beginning to thing it's maybe just a "thing" with this kind of equipment?

Would be interesting to know if anyone else gets similar "feedback" sounds (or whatever this phenomenon should be called.)

 

[TriplexDread]

On it's way out TC. Usually the transformer or capacitors oscillation problems. Usually just easier to buy a new one

Here's a good explanation;

http://superuser.com/questions/8324...supplies-generate-a-whining-noise-and-what-ca

 

[muckshifter]

I would replace it ... it may be ok if the fire brigade 'rescue' you in time.

 

[nivrip]

I've had the same in the past. Time to replace.

 

[Taffycat]

Thank you for your replies and advice @TriplexDread, @muckshifter and @nivrip. Much appreciated.

I found the article you linked to (TXD) very interesting. It looks as if there is a tendency for equipment of this kind to emit a sound, although sometimes higher than human hearing range.

The items we use, have, as mentioned, always whistled, when in use, but never when they are unplugged. (I noticed that the questioner mentioned in his post, that:

"This happens most often when they are not connected to a device or otherwise in use, and stop making noise when I connect a load to it such as by plugging in a device that is not fully charged."

Ours are completely silent when not in use. Their sound is barely audible when switched on (I'm the only one who hears them... bat-hearing perhaps? lol)

I'm tempted to contact the chair company to see what they have to say about their whistling adaptors. The chairs were pretty expensive and from a reputable company, so if the electrical connections they supply are in any way "iffy" it would be nice to have them send replacements.

Thanks again for the advice guys