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Rod McInnis
 
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Default cranking but no fire


"Netsock" wrote in message
...


The - side of the coil is connected to the points. When the points are
"open" the coil is being saturated. When the points close, the field
collapses, and make the voltage (spark).


You have this backwards....

When the points close current is allowed to flow, but current builds slowly.
At low RPMs the current will reach some maximum level deteremined by the
voltage and resistance of the coil.

When the points open the current path is altered. A basic principle of a
coil is that it is impossible for the current to change instantaneously, it
has to go someplace. As the points first start to open it will divert into
the condensor, which gives the points time to open far enough that the spark
won't jump the points. The VERY rapid rise in voltage across the condenser
is also coupled via a transformer action to the "secondary" winding which
generates the spark voltage.


Rod