One of my chargers (original Sharp, the US model 100-240V) has started making a high pitched buzzing noise when it's plugged in. Seems to work OK though. Should I get rid of it, or is it OK to use it?

Thanks for any info.

Felipe

Hi Felipe,

the EA-70 charger starts to buzz if it's in standby.
During the charging process, it should be silent.
This is a known thing since the first SL-5500 series
with a ton of threads around ("help, my ac adapter
humms after it finished charging my Zaurus...").

So, i wouldn't worry about it (at least, if it's a
relatively quiet humming sound). In our office,
we have to place an ear directly on the charger
to hear it

///TRIsoft

Marc Stephan

Thanks Marc. I actually have two of these chargers and one is buzzing a lot louder than the other. But as long as poses no risk, I'll keep it around.

Felipe

Usually this is becasue of badly fixed coil windings in a transformator, which then begin to vibrate due to the alternating current and resulting alternating magnetism.
Even the (lightweight and small) switched AC adapters have small transformators inside, so this could be the reason for Z adapters, too.

This is usually no risk, but if this vibrating gets heavier, it may theoretically lead to mechanical damage of e.g. the insulatoin of the coil wire. Not sure if this can happen and what it can cause.

daniel