I need a transformer to get 18VAC ~ 30-40W for a power supply. Living in Europe, I am looking around for a 220V - 18V transformer. As far as I understand transformers, I should also be able to use tranformer specified for 110V - 9V. Are there any technical reasons that should not work or I should not do that?
(I know varranties will be voided, but I do not care about that) (And yes, I have been building a few mains powered things before, so I know how to handle that safely)