what is a variac
A Variac looks like a sci-fi laboratory prop. For some reason, I have three of them in my shop, and yes, one is just a book end. But they do have a useful purpose. Variac is a generic trade name for a variable autotransformer.If that doesn't help explain much, let's look at what a regular transformer is, and how they relate to a collection of vintage arcade games.or some reason, I have three of them in my shop, and yes, one is just a book end. But they do have a useful purpose. Variac is a generic trade name for a variable autotransformer. If that doesn't help explain much, let's look at what a regular transformer is, and how they relate to a collection of vintage arcade games.