> > You may well find that the innards of the charger are identical whateve=
r the
> mains voltage marking. However because your unit is fitted with a plug
> intended to be used in a market where 110V is the norm, then that is what=
 it
> gets marked as. If fitted with a plug for a 230v market then it will be m=
arked
> for that. They don't mark it as a wide range (88-264) as to do so suggest=
s that
> people will attempt to use dodgy adapter arrangements to get their unit t=
o
> plug into a mains system they are not familiar with, with all the attenda=
nt risk
> of someone getting electric shock or worse.
> >
> > Come across this very scenario on model railway wall warts.
> >
> There is also a common design technique where the only difference
> between the ~115V and 230V configurations is a single link wire (or a swi=
tch,
> but I assume if your PSU had a voltage switch you wouldn't be asking this
> question). With the link disconnected the front end rectifier acts as a b=
ridge,
> with the link in place it acts as a voltage doubler.

Is that technique still used? With modern wide range SMPS chips I thought d=
oing that had dropped out in favour of the universal method which also save=
s having to change the board or switch.



--=20
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