I just finished building a 60 amp solar panel voltage controller and I would like to be able to measure the amperage. With the built in volt meter. I can insert a 1 ohm resistor in series but that would waste power and create heat. I have a old 120 v transformer and I was wondering if I removed the winding and passed one output of the voltage controller thru the winding, would I pick up any kind of voltage that would make sense? The controler is pure DC. The volt meter reads down to .01.