REFLECTOR: 24 volts vs. 12 volts

[Douglas Holub]

That's the impression I got from B & C's website; the only difference between the 24 volt and 12 volt alternator was the voltage regulator.
  ----- Original Message ----- 
  From: Ron Brown 
  To: Velocity Aircraft Owners and Builders list 
  Sent: Monday, January 24, 2005 12:26 PM
  Subject: Re: REFLECTOR: 24 volts vs. 12 volts


  By the way, isn't the voltage out put from a 12v alternator dependant on the voltage regulator?

  The reason I ask this, is that a friend's 172 has a 24v system, but the installed alternator was a 12v alternator and it was charging the 24v system just fine.  The voltage is a function of the voltage regulator.  I believe an alternator can put out close to 100 volts or more if the field voltage is continued to be applied.  I doubt there is much different between a 12v and 24v alternator other than the name plate.  

  But, I agree, the 12 volt system is lower cost if not a bit heavier (only a very few pounds) - eat fewer cheeseburgers!

  Ronnie 
    ----- Original Message ----- 
    From: Al Gietzen 
    To: Jim_Agnew_2 at yahoo.com ; 'Velocity Aircraft Owners and Builders list' 
    Sent: Monday, January 24, 2005 12:25 PM
    Subject: RE: REFLECTOR: 24 volts vs. 12 volts






    Not true, an alternator requires cooling for the heat produced in direct

    relationship to the watts produced.  12V x 50A = 600 watts = 24V x 25A.  If you

    have the same amperage output at 24V you have a 120W alternator.



    Jim



    I think the cooling is not a function of watts out, but of the watts of loss in the windings; I^2 x R.  I don't know what all else changes in the alt design for 24v, like number of windings; but I'd expect to get more output power from a 24v setup than for 12v for the same cooling requirement.



    Al



----------------------------------------------------------------------------


    _______________________________________________
    To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector

    Visit the gallery!  www.tvbf.org/gallery
    user:pw = tvbf:jamaicangoose
    Check new archives: www.tvbf.org/pipermail
    Check old archives: http://www.tvbf.org/archives/velocity/maillist.html


------------------------------------------------------------------------------


  _______________________________________________
  To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector

  Visit the gallery!  www.tvbf.org/gallery
  user:pw = tvbf:jamaicangoose
  Check new archives: www.tvbf.org/pipermail
  Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.tvbf.org/mailman/private/reflector/attachments/20050124/13c0e9e0/attachment.htm