Do transformers work the otherway around?

[TimFox]

See my quantitative example a few replies up.

[coppice]

>Any time I've seen a small transformer used backwards the results aren't great.

The explain : all transformators got LOSS , it is compensated by their winding number ratio to make up for it.

so if you take a transformator that is designed for 230V input and 23V output at x load..
it will deliver that voltage at that load.. the winding ratio is NOT exactly 10:1

this is very easy to reveal, when you use it backward , feed it 23V INTO its 23V winding.
one should expect to get 230V out at the watt/load it was designed for..
but you dont, you get a lot less voltage out, simply the winding ratio compensation only work when used the right way :-)

That just means you don't get quite the voltage you expect, but you get poorer voltage regulation as well with most transformer constructions. That's because you aren't using the optimal pairing of the windings. There are exceptions. The oval transformers with the primary on one arm and the secondary on the other are very symmetrical in their behaviour, because the primary and secondary are really no different in their construction.