Why don't AC adapters fry? Answered
I tore open an AC adapter to find out what I was doing wrong in my own power supply attempts. Before any other components, and connected directly to the outlet prongs, was a transformer. I know that it drops voltage and (by ohm's law) the amperage as well. But how does its survive the process? Why doesn't it have huge amounts of waste heat the way a current limiting resistor does?
Why doesn't the primary coil of the transformer--effectively a tiny wire short circuiting an AC outlet--burn up? I'm certain this has something to do with the impedance of an inductor, but I just can't figure out what!