The distributor cap is way too slow for a spark gap. Engine cylinders fire
in sequence and the gap break is routed through a different circuit each
time it fires. The purpose of the high voltage circuit is to provide
spark-based ignition and not electromagnetic resonance in a secondary coil.
As Jim said, the gap cannot be opened and closed efficiently enough to
break HV and provide the 1% to 5% duty cycle needed to set the resonance in
motion.
In a distributor, you have one gap and multiple circuits. In a rotary spark
gap, you have multiple spark gaps and a single circuit. You are reducing
your number of quenched spark gaps by an order of ten or so by going to a
distributor. If you increased the rotation rate of the distributor then you
are increasing the mechanical stresses you need to engineer to overcome. It
is very inefficient.
Dave Thomson
On Thu, Apr 17, 2014 at 5:20 AM, Jim Lux <jimlux@xxxxxxxxxxxxx> wrote:
> David Boyle wrote:
> I'm designing an srsg with an 7" phenolic disc and 4 tungsten points
> spun at 1800rpm by a half horse motor modified to be synchronous. Our
> transformer is 10Kv at 60ma. However a member of my team thinks that a
> rotary spark gap can be easily made from a distributor cap and rotor
> from a car. Is this possible?
>
> you can try.. but I'm not sure it will work very well. A distributor is
> designed more like a rotary switch: it doesn't carry any high voltage
> except when the rotor is near one of the electrodes. That is, it doesn't
> make and break the HV.
>
> If you search the archives, I'll bet someone has tried it, though.
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
>
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla