View Single Post
  #33  
Old 09-17-2012, 03:47 PM
downhiller's Avatar
downhiller downhiller is offline
livin large
Location: des moines
 
Join Date: Oct 2007
Posts: 7,072
Mein Auto: 2012 hypermotard 796
Quote:
Originally Posted by hornhospital View Post
Click the link that johnf posted and see what that says about the rotor of an alternator. It is NOT a magnet until it is energized by, guess what, the excitation voltage through it. And the test you got at Advance? Guess what the two wires to the alternator did before they started pulling current out of the spinning alternator? Yup...sent excitation voltage into it. Of course you'll get 14ish volts off a running alternator if you pull the wires. You already had it started with excitation voltage before you pulled the wires. An alternator's excitation voltage is self-sustaining once it's producing current.

I'm not trying to be an ass either, but I know alternators and electrical systems. I've been working on them for forty years.

Sent from my MB860 using Bimmer App
but it also mentions alternators that self excite after a certain speed, so if they can self excite, that means there has to be a magnetic field to start with, correct?
__________________
I know a lot about cars. I can look at a car's headlights and tell you exactly which way it's coming
Reply With Quote