Seems to me that we have a series circuit here. Battery terminal, switch, coil of wire, resistive element to limit dc current flow during coil initialization to protect the points from excessive pitting, points with condenser across them for the same reason and noise reduction, and a battery terminal.
Since current movement is the name of the game, the current is common throughout the circuit because there is one common wire which carries all of it.....except for the point-condenser interaction.
Seems to me it is more of a convenience in the design as to what is located where, and in the case of a 12v coil whether or not an external resistor is required. If my memory serves me correctly the 12v coil is just a 6v with an internal resistor; whatever it takes to limit the current to 2-4 amperes or whatever is the magic number to get the right energy in the circuit and not burn up the points.
The purpose of the whole circuit is to fill up the coil with the correct amount of energy required to fire a dirty, worn gapped, plug. As I recall it takes about 0.15 joules (watt-seconds). That energy is derived from energy stored in the coil during the charge cycle (points closed) through the relationship w =1/2 L(i squared). L being the inductance of the primary coil winding and "i" the value of the current through it at the second the points open. Then it's just a matter of setting the desired turns ratio for the secondary voltage desired at the plug.
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 - Restoration Story: 1951 Farmall H - by The Red (John Fritz). I have been a collector of Farmall tractors since 1990 when I first obtained part of the family farm in Eastern Indiana. My current collection includes a 1938 F20, 1945 H, 1946 H, and the recently purchased 1951 H. This article will focus on what I encountered and what I did to bring the 1951 NEAR DEATH Farmall H back to life.
... [Read Article]
Latest Ad:
Sell 1958 Hi-Altitude Massey Fergerson tractor, original condition. three point hitch pto engine, Runs well, photos available upon request
[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.
