In uk.d-i-y, TKM wrote:
Oh, that's interesting. I can see how an appliance such as an electric
stove could be wired to work on either 120 or 240; but how could a
toaster, fan or light bulbs, for that matter, be reworked for a
different voltage especially if the process involved just a few volts?
Seems like a transformer would be needed for each device.

IIRC devices that used a transformer, e.g. a radio, would have multiple
taps, and a voltage selector somewhere round the back. Usually the
voltage selector took the form of a removable jumper, with a variety of
positions (200V, 210V, 220V, 230V, 240V) arranged in a semi-circle
around the common connector, and perhaps 110V as well. My memory of
these is pretty hazy - no doubt someone can dig up a photo from
somewhere.

Of course it has to be remembered that each household then had *very*
few electrical appliances compared with today.

--
Mike Barnes