In article o.uk,
Dave Liquorice wrote:
So it looks like I may be lucky and simply altering them to series
will do it for 240v. Link brown and red and 240 goes between black to
orange?

Draws a picture to make sure, yes that is correct. B-)

It's a fairly standard looking transformer with the wires exiting from the
top of the bobbin and on every other ones of this type I've got they go
Winding 1 start finish Winding 2 start finish in a line. So for 240v you
just link the centre two and apply the 240v to the outer two.

Does it matter if one winding has the connections reversed when they are
in series?

Yes the fields generated will cancel and it won't work. It may also
get rather hot and go bang.

Quite - which is why I was asking. I wondered if the wires were standard
colours in the US. I do have a US transformer here with twin primaries,
and that has a red and a black but purple and yellow.

However, some exhaustive Googling found a pic of the insides of a device
from the same maker 240v connected.

It goes Red and Brown linked. Black to neutral, Orange to Line. Only
other difference (apart from obviously fuse value) is the 240v device has
a DP mains switch, the 110v a single pole one. I won't loose any sleep
over that. ;-)

Check the size of the smoothing capacitors, IIRC they don't need to
be quite as big at 60 Hz as 50 Hz. Not critical unless this thing is
going to be driven hard, which may cause the supply to have rather
more ripple than intended.

I'll risk that. No big deal to change if it proves a problem. Thanks.

--
*I love cats...they taste just like chicken.

Dave Plowman London SW
To e-mail, change noise into sound.