Hi guys, I am rather new here and would like to pose a question about transformers. As physics assignment I am supposed to make a model of an AC transformer, for which I grabbed an AC/AC step down adapter (something like these here: http://www.digikey.com/product-sear...internal-off-board/ac-ac-wall-adapters/590573) , my model (with coils on two sides around a soft iron core) and a multimeter. So I cut open the wire in the AC to AC adapter (230V to 12V 0.7A) and plugged in my adapter which would be connected to my model's primary coils, and the secondary coils would then be connected to my multimeter. My multimeter showed that it stepped about 12~V down to 6.0 V for coil ratio of 50:100, so I thought it was fine, until the adapter kind of stopped functioning. My question is: Is anything wrong? Did the transformer in the adapter spoil due to a short circuit or something? If so how do I fix it/ prevent it if I get a new adapter? Please do help me out, thanks!