This first paragraph is just an update for anyone who reads all this, the thing I am talking about in the paragraph below is called an A/C adaptor. My husband got them for the xbox 360 and the Wii from ebay, the Wii one only cost $15. Then you don't have to mess with a transformer which can long term damage your electicals if you don't have the right one running. The bigger the stronger? I also blew up my Dyson on a transformer and have had a really bad electric shock from a transformer last year that was running to our old xbox, that died (since upgrading to 360 changed to A/C adaptors) I refuse to allow transformers in my youngest sons room.
We have just bought a Wii for our youngest. You can use it over here but either on a transformer which we hate to use or you can do what my husband has done (he got the same thing for the xbox 360) you can buy a special transformer, he got ours on ebay for about $24 it plugs into the wall from the Wii itself, that way you don't have to mess with a transformer and the polarity stuff. OK so that is how I understand it. I too know nothing about electrical stuff. But I do know he hates transformers they are not good for your electrical things I blew my Dyson the first time I used it here on a transformer. But the thing he got for the Wii and Xbox work perfectly just like a regular cord with a little box in it. If you need more clarification later when my husband is awake, (doing night shift this week) I will find out exactly what it is. My son will get his given to him this Saturday for his birthday.