i would be carefull about how much work you put in.. .. .P.P description is all you really need to know. I was just being a sad engineer trying to work out why it didn't fit my theortical knowledge. Even in the ATPL's it doesn't go into the detail we have discussed of how and why the alternator is designed the way it is.. .. .If you really wnat to know whats required get your hands on a copy of the Oxford Jepp notes on aircraft systems. Transair sells them.. .. .MJ