[TR] Static Timing

[Nolan]

> Actually, the voltage at the points never exceeds 6 - 12 vdc (ballasted or 
> unballasted coil).

The points see quite a high voltage.  The whole system is a tuned LCR 
circuit.  Just like a spring, a weight and a damper.  When the field 
collapses and fires the plug the whole thing promptly rebounds the other 
way, just not as high.  This voltage is seen at the points.  It rebounds 
again, not as high, and frequently fires the spark plug a second time.  This 
cycling continues, progressively diminishing, until it settles down.

The capaciter is there in the circuit to dampen down this oscillating.  It 
stops it quickly and gets the circuit ready for the next spark plug firing. 
Incidentally to this dampening the capaciter helps prevent arcing across the 
points when the voltage surge rebounds.

You can hook up the ignition to a scope and watch this.