Coil + magnet = power source.

People, I need your help! I'm a student at college and my primer subject is physics. Let's just say I know enough about electricity and power. But my major obstacle towards constructing stuff is electronics. I have only just scratched the surface of it. I want to make a power source out of a coil and a magnet inside (electrical induction). Can anyone point out how exactly to build the thing? My desired output voltage is about 5V, or sth. I'll use it for electronics, so the amperage doesn't really matter. I would also like to see a circuit that converts AC to DC, cause the coil will give out only AC and that's not good. Thanks in advance!

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