Posted by John T on December 26, 2007 at 16:11:15 from (66.244.83.147):
In Reply to: Re: 12 volt front coil posted by TractormanNC on December 26, 2007 at 15:41:47:
Hi Leonard, Something that could have contributed to the difference is the ohms values of the coil and the ballast resistor you used.
In the IDEAL situation the ballast resistance (around 1.5 ohms) would be near the same as the coils primary (also around 1.5 ohms) such that a true 50/50 voltage divider existed and the coil saw a full 6 volts as designed for. HOWEVER coils varied from maybe 1.25 ohms to under 2 ohms and likewise Ive seen those ballast from 1.5 to 1.85 ohms SOOOOOOOOOOOOOO when you bought an of the shelf ballast it may have been on one end of the spectrum and if the coil was on the opposite end you may have ended up with a voltage divider that only applied 4.5 to 5 volts on the coil i.e low current and a weak spark. HOWEVER that problems not there on that full true 12 volt coil.
Or else maybe (say the voltage divider left sufficient voltage on the coil) the old coil was simply showing its age and that brand new just yielded more spark gap energy as there were less losses to heat or other inefficiencies.
Fun chat, theres other possibilities but I gotta run, will check back later
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - A Cautionary Tale - by Ian Minshull. In the early 1950s my father bought an Allis Chalmers B and I used it for all the row crop work with the mangolds and potatoes, rolling and the haymaking on our farm. The farm and the Allis were sold and I have spent a lifetime working on farms throughout the country. I promised myself that one day I would own an Allis. That time event
... [Read Article]
Latest Ad:
1964 I-H 140 tractor with cultivators and sidedresser. Starts and runs good. Asking 2650. CALL RON AT 502-319-1952
[More Ads]
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.
