# using a step-up voltage transformer designed for 110V input with a 100V input

I relocated to Japan (where electricity is served at 100V) recently and I am looking to buy a step up voltage transformer to be able to use my TV which accepts 220-240V.

While I managed to find some options, it seems that majority of the transformers out there are designed for US-Europe conversion, ie accepting input of 110V and not 100V.

Could I use such a transformer instead, assuming it can generate output of 240V? (I'm assuming transformers work in multipliers, so a "max transformation ratio" would be 240/110, and 100*(240/110) would get me very close to 220V). Are there any other considerations why I should not try this besides voltage calculations?

• No problem using a 110V transformer on 100V. But I would look the TV set spec. Newer TV can accept very wide inut voltage range. – Marko Buršič Nov 5 '18 at 9:12
• Transformers for this purpose are usually just 1:2; 110 to 220 or 120 to 240, for example. So you might have trouble finding an 11:24 transformer, though they probably do exist. – Hearth Nov 5 '18 at 10:58
• @Marko unfortunately, the TV spec says 220-240, I double checked on the TV itself and in a reference guide. What could happen if the transformer outputs only 200V (ie 1:2 ratio), I assume the TV simply would not work? – Aurimas Nov 5 '18 at 11:32
• Get a 110volt : 18volt transformer, and wire it to boost (not buck) the line voltage. Stack the 18 volts atop the 100 volts, in an insulated box, placed beside the TV. Your safety may vary. – analogsystemsrf Nov 5 '18 at 11:41
• @Aurimas I am pretty much in the same boat as you were. What did you do in the end? – Captain Fogetti Jan 18 at 12:25