Thanks guys really but I've opened up another can of worms for myself
I've just found this:
"How is electrical power generated and stored on the DA42?"
-"It is generated via 2 60amp, 28volt DC alternators"
Lol I mean a DC ALTERNATOR?! What the hell?!
This would seem to lean towards what Mozella was suggesting regarding an inbuilt DC generator within the assembly for the purposes of initial excitation. Am I right or wrong Mozella?
A quick look on wikipedia revealed this:
"Direct connected DC generator[edit]
This method of excitation consists of a smaller direct-current (DC) generator fixed on the same shaft with the alternator. The DC generator generates a small amount of electricity just enough to excite the field coils of the connected alternator to generate electricity. A variation of this system is a type of alternator which uses direct current from the battery for excitation, after which the alternator is self-excited."
So I'm assuming that the reason they are called DC alternators is due to the initial excitation being obtained by a 'smaller DC generator. However a 28V 60A generator doesn't sound so small considering the main battery which can power the main electrical buses (albeit for a limited time) is only 24V 10Ah
Any thoughts?