[Today’s run: Pike road 5+ miles]
One thing I picked up at the Jackson, MS hamfest in January was an old isolation transformer. It was lying under a guy’s table of stuff. I asked him how much he wanted for it and he said $10. Good deal! So I bought it.
An isolation transformer is a transformer. So it has a core material with two or more coils of wire on the core. (In this case just two). Transformers only work on alternating current of some type. The electricity coming out of our wall sockets is alternating current (AC), and you will frequently find a transformer in the power supply of something electrical you plug in to the wall.
Most of the time a transformer is used to change the voltage of the AC source, stepping up or down. They do this by having a different number of turns around the core for the wall-socket side and the electric gizmo side. The difference in turns gives you a different voltage; the ratio of the turns is also the ratio of the voltages.
But an isolation transformer doesn’t change the voltage. What it is supposed to do is isolate the wall-socket side from the electric gizmo side so that there is no direct current path from one side to the other.
One place they use these things is to provide power to a boat while it is docked. If you don’t use an isolation transformer you can get nasty galvanic corrosion on parts of the boat.
I don’t have a boat.
Another place to use an isolation transformer is when you are working on an electronic gizmo and you want to measure things. Without an IT you may have voltages between the box of the gizmo and the box of the volt meter or oscilloscope or whatever. That would be bad if you are touching both of them. But the isolation transformer keeps that from being a problem.
Anyway, when I got this thing someone had cut the cords off of it, both the wall-socket side and the electric gizmo side. So I opened it up and wired it back up. Markings inside lead me to believe it is a Stancor GIS-1000. I used the diagram on this page to wire it up. I also used gorilla glue to attach an electrical box to the top. That lets me turn off and on the connection on the electric gizmo side of things.
We used this transformer when working on the Silvertone Console. I plan to use it frequently in the future.
