Simple plug-in 220V to 110V converter

My garage has either electric heat or none at all and my heaters blow the circuit breakers every time I try turning anything else on. HOWEVER I have a 220 circuit originally for a welder that I imagine would handle them easily. So, does anybody have a way to make a simple, plug-in adapter from a 220 circuit I seldom use to be able to plug in 110 heaters? (all the circuits are in the US)

Check your products, some things like computers can run on 220V and 110V.
If not you'll need a transformer, you can get one for like $30. Might be able to get one cheaper if you find out someone who just came from South Korea.
Unless you are drawing a serious amount of power, a few heaters shouldn't be causing any problems, so you might want to check the fuse box and wiring. In theory, connecting a pair of 110V heaters in series should allow direct connection to the 220V supply.