Thinking in automotive terms...I am wondering how to tell the difference visually between an automotive generator versus a automotive alternator when placed side by side. Assuming both have external regulators and also bearing in mind that neither work properly.

One source tells me it's an alternator, yet another tells me it's a generator. All I know is it doesn't work properly.

thks

 

Well, the best way to tell is to look at the commutator.
A generator has a segmented commutator, where an alternator has slip rings instead; no segments.
http://www.rowand.net/Shop/Tech/AlternatorGeneratorTheory.htm