How alternators work in a nut shell:
The parts of an alternator are the rotor, stator, brushes, slip rings, volt regulator, and rectifier. Basically the rotor becomes a electromagnetic by voltage being applied through the brushes and slip rings to the windings of wire on the rotor. The interlacing fingers of the housing surrounding the windings, create north and south poles. The stator surrounds the rotor. The stator is made up of three separate wires, rapped around in small coils, in a full circle. As the rotor spines, inside the stator, the magnetic field moving past the wires (in the stator) will produce or induce current flow in the wires. Now this is creating AC but we need DC. Diodes in the rectifier help us with this problem. Diodes only let current flow in one direction.
Now I know there is more detail than this. There is more stuff about three-phase voltage, wye connection, delta connection, voltage regulator, and what not. Maybe I'll talk about it later.
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