Timzsta
You are correct for large aircraft , they do tend to use various a.c.
voltages for different services as well as TRU's (transformer rectifier units ) and inverters .
In the case of the Pretolite Alternator, the full wave rectification is internal to the alternator and the two teminals on the back are as stated ie
1) 60 amps d.c. output
2) AUX terminal connected to the star point.
Why the Star Point which is A.C. when you only have access to one side of the A.C. circuit?
By the way there are two more terminals connected to the two brushes for the slip rings of the Rotor. One teminal is connected to Earth and the other is connected to the Regulator which supplies the d.c. excitation current / voltage the level of which is controlled to vary the d.c. current output at terminal 1) depending on battery condition.
Regards.