110V/240V transformers

[synnie]

Just a general question in regards to how transformers work.We have 230-240V Transformers in Oz, while US have the 110V setups.My question is, if i got a toroidal from the US which is 110V input and 12-0-12 output, when i plug it into 240 would it output 25-0-25V? Have seen a couple of toroidals around which will run 110 or 220V depending on if you wire up the input in series or parallel (4 input wires).Just doing price checks on a couple of 24 and 36V toroidals which will finish of my power needs this year(hopefully)

[Matt_Edwards]

for a very short time yes.
However, if I remember my electro magnetics correctly, as you double the voltage, you will also double the flux in the magnetic core, which will get a lot hotter than it should.
Also applying Ohms law to the primary winding means you will also have more current in it than is it is rated for.

So Please don't do it.

BUT if you see a Toroid that has two Primaries you can of course put them in series to get 240v.

Cheers
Matt

[synnie]

Thanks Matt, im not in the habit of doing things unless i know im not going to fry myself or the house.With the price tortech have atm ill grab them instead now
Cheers G