A DC generator has a commutator and produces DC voltage...A AC generator has slip rings and produces AC voltage.
Your automotive alternator has slip rings and produces AC voltage that is rectified into DC.
The voltage regulator, either on the firewall, or "SI",inside the alternator proper, regulates voltage and current for the system, based on its needs, and how the regulator was adjusted.
For the layman, the house is AC and the car parked in front is DC...you should have taken auto shop AND physics!
AC/DC-Stu
