djk — The need for very localized DC generation from rotating machinery would almost have had to have been the case, given voltage drop in relatively low-voltage DC distribution conductors. It seems about ½ mile was the most optimistic extreme for DC circuit lengths without distribution conductors getting ridiculously huge.
The prime advantage of AC transmission and distribution is making use of the AC transformer, to raise [and then lower near the load] voltage, having sent it at a much higher voltage {with much lower losses.}
The one other major advantage of AC is its ready use for brushless induction motors—the ‘current chopping’ needed for DC motors through brushes, commutator and armature generally became no longer necessary with AC.
It is said that early on, Nikola Tesla was hired by Thomas Edison to fix excessive commutator sparking problems in early DC generators and motors.
[This message has been edited by Bjarney (edited 09-17-2003).]
