7197 Mississippi Street, Merrilluille, Indiana 46410.
Some of your readers are undoubtedly using Model 'T' Ford coils for their gas engines. The intent of the table below is to show voltage and FREQUENCY change with Ford magneto speed.
You will note that the frequency is independent of any deviation in the load on the magneto, but is a direct linear function of the revolutions per minute of the magneto.
This leads up to statement that the impedance of the 'T' coil is increased as the frequency increases. This is quite necessary because if the frequency stayed low, while the voltage rose, the coil would be subjected to over-current with possible burn-out or at least shortened vibrating contact life. Now; if you put pure D.C. into the coil it means that a lower voltage may be used.
This was taken into account by Henry's
excellent engineers as evidenced by the fact that they designed it to operate on a 6-volt battery when not switched onto the magneto.
The criterion for proper voltage is to see that 1.2 to 1.4 amperes were flowing while the coil is buzzing.
A more practical test was to adjust so that the high voltage spark would jump ?' in free air.
Operation of the coil with no external jump path is in itself a gamble and using a voltage higher than necessary can cause internal shorting and possible subsequent failure. Incident to the foregoing statement, I might say that I know many of your readers have healed an internal high voltage winding short by simply warming the coil sufficiently to cause the insulating compound to ooze back into the rupture.
In closing, I want to thank all the people who take enough time to tell about their interest in this great hobby we share in common.
Pictured is a photo of me and my 'Separator' tiller. I call it this because it is the kind of machine that will separate the men from the boys.
It was given to me as junk and I was mainly interested in the magneto but it ran so well that I used it in my garden this spring.
It is a very old Simar, type C2J which has a two-cycle engine made in Switzerland. It does a really fine job of tilling, much deeper and better than the new type tillers. The only thing you have to look out for is hard ground because when it hits that, it takes off like a scared rabbit.
Courtesy of William H. Payne, 111 Pratt Street, Madison, North Carolina 27025.
Miles per Hour
Cycles per Second