User-agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:49.0) Gecko/20100101 Firefox/49.0 SeaMonkey/2.46
Hi Terry,
Racing sparks typically occur when energy is being injected into the
secondary too quickly. Although this is _usually_ caused by
excessively-high coupling, it can also occur when the bang size is too
large for the size of your secondary, or if your system is significantly
out of tune. To solve the problem(s), you'll need to first insure that
your system is in tune, that P:S coupling is not excessive, and that
your toroid is appropriately sized for your system's peak output voltage.
1. Tuning:
I'd suggest initially running the system with a breakout point (or barb)
during this phase. Reduce the primary spark gap length to reduce maximum
bang size. Experiment with primary tap point until you get the maximum
secondary spark length at a given variac setting. The system should be
smooth running with consistent spark length under continued operation.
2. Coupling:
If you don't see any racing sparks, slowly increase the "bang size" by
widening the main gap slightly. Don't increase gap length beyond the
point where the safety gaps begins firing or if you start to see racing
sparks. If you see racing sparks, reduce coupling slightly and continue
the process of increasing the main gap length until you can run at full
power with no evidence of racing sparks. You may need to retune the
primary a bit by increasing primary inductance slightly (i.e., moving
the primary tap outwards 1/8 - 1/4 turn) to compensate for capacitive
loading of longer secondary streamers. Any signs of racing sparks mean
that you need to further decrease coupling.
3. Final tweaking:
Reduce the length of the breakout point/bump to see if the coil can
self-break from the toroid as you approach full power without
introducing any racing sparks. Further decrease coupling if you see any
evidence of racing sparks. Ideally, an appropriately-sized toroid will
self-breakout before you reach full power. Failure to self-breakout can
occur if the minor toroid diameter is too large (requiring
excessively-high breakout voltage) or if the major toroid diameter (and
capacitance) is too large, which reduces maximum topload voltage below
the point of self-breakout. For this case you may need to operate your
system with a breakout bump or point to insure breakout. Even with an
optimal setup, you may still need to use a breakout point during humid
weather when it's significantly more difficult to initiate breakout.
Good luck,
Bert
--
Bert Hickman
Stoneridge Engineering LLC
http://www.capturedlightning.com
+1 630-964-2699
***********************************************************************
World's source for "Captured Lightning" Lichtenberg Figure sculptures,
magnetically "shrunken" coins, and scarce/out of print technical books
***********************************************************************
Terry Oxandale wrote:
It's been a long time since I was more active on this list. I never was a
"technical" enthusiast, so being I've had the coil in storage for probably
10 years, and have forgotten more than I remember about coiling. I'd like to
tap the group for some help or advice please.
My coil appears to operate as I remember it did, as long as I've got a sharp
pointed barb sticking out the side of the toroid to promote a discharge.
When I remove the barb to get a normal toroial discharge, I get racing
sparks along the secondary, and nothing out of the toroid, all for the same
power setting as the "barbed" setup (2kva). Thus I separated the secondary
from the primary in terms of vertical distance to lower any excessive
coupling (shooting in the dark here), but still racing arcs along the
secondary.
Any ideas on the huge difference (or lack of performance) between "barbed"
and "non-barbed? No component changes have been made since a decade ago when
it all worked great, and both configurations performing equally well.
Terry
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxxxxxxxxxx
https://www.pupman.com/mailman/listinfo/tesla