ALTERNATOR
The elementary 3-phase 2-pole synchronous generator has a
stator equipped with 3 coils displaced 120o from each other;
although shown as concentrated, they actually are distributed.
When the rotor is excited with dc and rotated, the resultant
field will also rotate so that sinusoidal voltages are generated in the 3
stator phases, displaced 120o in time and having a frequency
directly related to rotor speed.