I would ask you this, Have you ever looked inside of a usb charger. Most
have no fuse and the switch mode supply is driven directly from the mains
via a semiconductor driving the primary of a transformer a very tiny
transformer, at a high frequency, the other side is connected to a very
simple rectifier and voltage stabilising chip.
You are in effect relying on a cheaply made tiny transformer to isolate
you from the full mains voltage.
I'd no chance it knowing what I know about these things. I have had more
than one fail one very spactacularly and trash the device on it. Crap.
Brian

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This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"polygonum" wrote in message
...
How dangerous would it be to use a phone or tablet in the bath whilst it
is connected to a mains-powered USB charger?

Obviously it could be dangerous to the device itself if you drop it into
the water!

Obviously a 5 volt low current supply isn't usually life threatening.

Obviously we have rules about sockets in bathrooms. But a long USB cable
to a socket in another room seems a likely way round that.

But if something is wrong somewhere, such as a mis-wired USB charger,
could there be any appreciable danger?

Is there in future likely to be a bathroom-safe USB socket next to the
shaver and toothbrush socket?

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Rod