Yesterday's Tractor Co. Low Prices, Parts Ship Fast!
Click Here or call 800-853-2651 
   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
 
Marketplace
Tractor Manuals
Tractor Parts
Classified Ads
Photo Ads

Community
Discussion Forums
Project Journals
Tractor Town
Your Stories
Show & Pull Guide
Events Calendar
Hauling Schedule

Galleries
Tractor Photos
Implement Photos
Vintage Photos
Help Identify
Parts & Pieces
Stuck & Troubled
Vintage Ads
Community Album
Photo Ad Archives

Research & Info
Articles
Tractor Registry
Tip of the Day
Safety Cartoons
Tractor Values
Serial Numbers
Tune-Up Guide
Paint Codes
List Prices
Production Nbrs
Tune-Up Specs
Torque Values
3-Point Specs
Glossary

Miscellaneous
Tractor Games
Just For Kids
Virtual Show
Museum Guide
Memorial Page
Feedback Form

Yesterday's Tractors Facebook Page

Related Sites
Tractor Shed
TractorLinks.com
Ford 8N/9N Club
Today's Tractors
Garden Tractors
Classic Trucks
Kountry Life
Enter your email address to receive our newsletter!

subscribe
unsubscribe
  
Farmall & IHC Tractors Discussion Forum
Show Parts for Model:

positive to negative ground

Welcome Guest, Log in or Register
Author  [Modern View]
Moondoggie

02-04-2013 13:58:30
66.206.51.249



Report to Moderator

I am curious about the change over from 6volt positive ground to 12v negative ground. I thought reversing the polarity on a DC circuit would cause certain DC motors to reverse rotation. On a reverse of the + to - grounds, does a change have to be made to the starter so it doesn"t operate in reverse?




[Log in to Reply]   [No Email]
mkirsch

02-05-2013 05:58:17
64.80.110.74



Report to Moderator
 Re: positive to negative ground in reply to Moondoggie, 02-04-2013 13:58:30  
There are no magnets in a starter motor. BOTH the armature (spinny part) and field (outer can part) are electromagnets, and they're connected in series. Hence the term "series motor."

You'll also notice there are no magnets in generators, or alternators. The only place you'll find a magnet on an antique tractor is the magneto.

Because the armature and field are wired in series, when you reverse the polarity of the battery, you reverse the polarity in the stator, and you reverse the polarity in the field. The starter turns the same direction no matter what.

It has the same effect as a "double negative" in a sentence:

I know something. = I don't know nothing.

[Log in to Reply]  [No Email]
Jon Hagen

02-04-2013 20:50:09
69.26.17.61



Report to Moderator
 Re: positive to negative ground in reply to Moondoggie, 02-04-2013 13:58:30  
No, motor rotation only changes with polarity in a motor with permanent magnet fields. You only find those on small engines and a few modern automobils.
A conventional starter motor with field coils will rotate the same normal direction when wired either pos or neg ground.



[Log in to Reply]  [No Email]
John T

02-04-2013 18:27:39
71.52.103.159



Report to Moderator
 Re: positive to negative ground in reply to Moondoggie, 02-04-2013 13:58:30  
As posted below, the direction of rotation in your electromagnetic field starter tractor WILL REMAIN THE SAME REGARDLESS OF SWAPPING POLARITY.

To reverse its rotation you have to change the polarity relationship between the Fields and Armature.

If it were a Permanent Magnet motor (NOT electromagnetic field) and you change polarity IT WOULD RUN THE OPPOSITE DIRECTION

John T



[Log in to Reply]  [No Email]
David G

02-04-2013 14:28:36
205.215.206.18



Report to Moderator
 Re: positive to negative ground in reply to Moondoggie, 02-04-2013 13:58:30  
It will reverse permanent magnet motors, starters are not.



[Log in to Reply]  [No Email]
John G. Hasler

02-04-2013 14:53:57
174.124.25.60



Report to Moderator
 Re: positive to negative ground in reply to David G, 02-04-2013 14:28:36  
> It will reverse permanent magnet motors, > starters are not.

It will reverse PM DC motors and also shunt-wound DC motors if both field and armature are not reversed. It will not effect series motors such as starters because in them the armature and field are internally wired in series so you can"t reverse just one.



[Log in to Reply]  [No Email]
David G

02-04-2013 15:34:45
205.215.206.18



Report to Moderator
 Re: positive to negative ground in reply to John G. Hasler, 02-04-2013 14:53:57  
agreed, thanks



[Log in to Reply]  [No Email]
Zachary Hoyt

02-04-2013 14:20:54
50.122.169.86



Report to Moderator
 Re: positive to negative ground in reply to Moondoggie, 02-04-2013 13:58:30  
The starter rotation is not affected. I have no idea why, electricity is a closed book to me except for the few things I have specifically learned to do.
Zach



[Log in to Reply]  [No Email]
teddy52food

02-04-2013 17:36:51
184.94.175.179



Report to Moderator
 Re: positive to negative ground in reply to Zachary Hoyt, 02-04-2013 14:20:54  
When you reverse the current in both the armature and the field, the rotation stays the same. In a starter with permanent magnet fields, if you reverse the armature current, it will turn backwards.



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:

TRACTOR   PARTS TRACTOR   MANUALS
Same-Day Shipping! Most of our stocked parts ship the same day you order (M-F).  Expedited shipping available, just call!  Most prices for parts and manuals are below our competitors.  Compare our super low shipping rates!  We have the parts you need to repair your tractor.  We are a Company you can trust and have generous return policies!   Shop Online Today or call our friendly sales staff toll free (800) 853-2651. [ More Info ]

Home  |  Forums


Copyright © 1997-2014 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters