On Feb 20, 11:09 am, > wrote:
> "Don" > wrote in message
>
> ...
>
>
>
> > You are correct. You beat me to it. Seems like there are a lot of
> > people out there equating this condensor to condensor as in "points
> > and condensor." WRONG!!
>
> > Don
> >www.donsautomotive.com
>
> It is more a matter of degree than the electronics behind it for the
> regulator.
> RFI suppression capacitors can be used at a lot of places where there is
> no functional or fundamental need for the.
>
> The need for the capacitor is much more in a Kettering points setup, not so
> much for RFI protection but to lengthen the life of the points themselves.
> Left alone, the current through the points and the arcing due to this
> current
> can transfer metal from one face to the other causing early failure.

There's more to it than that. The arc that jumps the points
as they open represents continued current flow, reducing the sharpness
of the magnetic flux collapse that generates the spark voltage in the
secondary. The condenser provides a temporary path for the electron
flow as the points begin to open, and by the time the capacitor is
full the points are too far apart to start any arcing, and the current
stops much more abruptly. A bad (open) condenser will kill the engine
just as quick as a shorted one.
Just try starting the engine without the condenser installed;
it won't run. Not enough spark. The automotive textbooks I've read
have only the "points-burn prevention" theory as the reason for the
condenser. Not until I studied for my aircraft maintenance engineer's
ticket did I find the real reason for it in the aircraft texbooks. An
old guy once told me many years ago that the (auto) engine wouldn't
run without the condenser; he didn't know why, just that it wouldn't.
I tried it, and sure enough, dead as a doornail.
My Unison/Slick magneto manual says that the condenser also
boosts the mag primary current for the next firing; this is true only
because the magneto generates alternating current for the primary, as
opposed to the DC system in the car.

Dan