I have a power transformer and i forget where it came from. It has two leads from a wall outlet plug and then goes to the main (square) casing. there are three wires that come out the other side. They are from left to right, red,white and red. I assume its a 9v ac to dc transformer but am not positive. Can someone help me? I suspect that the white wire is ground. Any help would be great.
There's no reason to assume anything, except that the primary side (with the line cord and plug) is probably intended for 115 Volts, AC. If it's a transformer (rather than a power supply) it's not AC to DC at any voltage. Transformers convert AC to AC. With those colors on the secondary, there's a pretty good chance it's center-tapped. Red-to-red will be twice the voltage of either red-to-white. Nothing should be grounded to the transformer case.