I have an transformer from a old power supply. It has 2 red wires and 2 yellow wires. I think the red wires are the high voltage (mains) in and the yellow the low voltage (12v ?) out, To check this I touched a 6V battery across the yellow wires and got a high voltage across the red wires (enought to spark across a 3mm gap) But when I measure the resistance across the red wires I get 31.1ohms and across the yellow 10.4ohms. This is not what I expected. I thought the high voltage winding would be thicker wire and less turns than the low voltage winding and so would have a lower resistance. Could anyone explain where I am going wrong?
- posted
16 years ago