In message , Peter Stockdale
writes

"Mike Clarke" wrote in message
...
In article , Peter Stockdale
wrote:

It would also be nice to get one that did not have the 110v. option.
Presumably this could be produced cheaper and could be smaller

Probably wouldn't make much difference, the 110v socket will just be fed
from a centre tap in the transformer secondary so you're only saving on
the cost of the second socket. The transformer would be the same size
and probably governs the overall size of the unit.

--
Mike Clarke

Sorry Mike, you have me lost here.
Why would a transformer be needed for a 240v. toothbrush charger or a 240v.
razor ?
Surely the only "transforming" necessary is to cope with the 110v.
situation.

Isolation from the mains. The secondary is floating and cannot source
more than a few microamps of current if you touch either wire, even if
you are well earthed. Of course, if you touch both...

The same reason as isolation transformers are used for power tools
outdoors. Yes, you can use circuit breakers of various types, but an
isolation transformer can't go wrong.
--
Joe