Alternators: brushed or brushless

The way I figure it, if its good enough for Toyota then they must be reliable. Hard to beat Japanese stuff.

 

All alternators brushed one way or another. In beginning of 20 th century alternators were brushed to convert AC in to DC.The field was controlled by buzzer device to keep voltage in range. After powerful diodes were invented modern alternators has 3 phase rectifier( 6 diodes) to convert AC to DC so no commutation needed.
Field current controlled by semiconductor device integrated in to brush holder assembly.
Now brushes life is very long because current is really small. About 15 - 20 amp's.
Most likely the bearing will fall before the brushes.