Dave Osborne was thinking very hard :
Well, that's not true Harry. Anything with a transformer and a linear
regulator is going to use less energy as the mains voltage falls right down
to the point where the dropout voltage in the regulator is reached. The
regulator will then shut down and your tech kit won't be using any current at
all...

IOW Up to a point, for linear regulated power supplies, reduced mains voltage
will reduce unnecessary heat dissipation (and more than likely prolong the
life of the electrolytic caps to boot.)

Agreed, but I can't think of any item of equipment in this house which
is in regular daily use, which still uses a linear regulated PSU. Even
my phone charger is a SMPSU. I do of course have lots of test gear and
lots of home built stuff which uses linear supplies, but these are not
in what I would call regular domestic usage.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk