Electricity comes in two basic forms: Alternating Current (AC ... a generator in one box. You could spin the motor with 12V and have the generator produce a different voltage (even a DC voltage).

why do carmakers no longer use generators, which produce rich, creamery DC electricity? Why would it make any sense to generate AC, and then have to convert it to DC? As you probably guessed ...

This is alternating current or ac. The output of an alternator can be ... field increasing the number of turns on the coil The diagram shows four different positions of the coil in an alternator ...