Hello, I bought a 20 amp 110 volt variac from an estate this past weekend. I would like to know what is the correct way to hook up the beast. It is made by American Transformer Co. and the catalog number is 27666. It has four terminals marked 1,2,3 and 4. Can I assume that 1 and 2 are input and 3,4 are output? Thank you, Steve Fitzgerald N4KQR Tampa FL