Strange Spark Phenomena

From:  Thomas McGahee [SMTP:tom_mcgahee-at-sigmais-dot-com]
Sent:  Thursday, January 29, 1998 8:17 AM
To:  Tesla List
Cc:  gweaver-at-earthlink-dot-net
Subject:  Re: Strange Spark Phenomena

> From:  gweaver [SMTP:gweaver-at-earthlink-dot-net]
> Sent:  Wednesday, January 28, 1998 11:09 AM
> To:  Tesla-at-pupman-dot-com
> Subject:  Strange Spark Phenomena
> I fired up my tiny 1.5" TC today.  I changed the sphere from 2" to 4".
> Changed the cap from .0014 uf to .005 uf.  Changed the spark gap from 4 gaps
> .025 each to 3 gaps .025 each.  Moved primary tap from turn 5 to turn 3.
> Spark output increased from 3" to 6".  The power supply is a furnace
> ignition transformer 6K 20 ma.  120 watts.
> The output spark is strange.  I have seen this phenomena before but haven't
> thought much about it until now.  The first 2" of the output spark is very
> thin, the next 2" are very hot, thick and blue, the last 2" are very thin
> like the first 2".   How can a spark that is all one continuous spark be
> made up of 3 sections?  How can the center 2" of the spark be hotter and
> thicker than the ends of the same spark?
> Gary Weaver

Take a length of nichrome wire, attach it to two clip leads and turn up
the voltage. The center will be glowing red hot while the ends are dull.
Simple heat-sinking effects.

Your sphere is a heatsink. The place where the arc strikes is a heatsink.
I am assuming that you are drawing the arc to a grounded wire.

Besides the heat-sinking effect, there is also the increased heating
effect that comes from being surrounded by other hot objects. The
objects in the center will be much hotter than the objects around
the periphery.

I'm not saying these are necessarily the reasons for your strange
arcs. I do not know all of the conditions under which these arcs are
occuring. But I do know that at low powers you can see things that
are greatly masked at high powers. And vice versa.

Do the arcs exhibit the same peculiarities both when striking to a 
ground and when just brushing out into the air? If they exhibit them
ONLY when arcing to a ground, then the above effects are probably
at work. If not, then something else is probably at work here.

Hope this helps.
Fr. Tom McGahee