When I was a kid, I took the timer out of the washing machine my father was getting rid of. With some experimenting, I found which terminals closed and opened circuits. I had two trains running on the timer as well as lighting and some home made animated items. My father, not being mechanically inclined, was impressed.
The timer itself ran on 110 volt house current. The terminals were separate from the house current so I was able to run the power leads from the transformer to the timer without having to worry about the house current.
That's history. This is what I found on All Electronics. I didn't delve into the details, but you may want to look closer.
