Re: [TCML] max performance per secondary diameter/resonate inductor.

[futuret@xxxxxxx]

Scott,

Generally speaking, you should be able to get longer sparks from a given
secondary size at high bps compared to low bps.  This is because the
bang size is much smaller at high bps (for a given input power) so it
stresses the secondary less.  The ability of a secondary to survive high
input power should depend more on the length of the coil than on the coil
diameter I would think.  Much also depends on the type of wire insulation,
number of turns, secondary coating,  toroid size, presence of a corona 
ring on top of the secondary, shape of the primary, etc..   On my old
research coil which had a 4" x 23" secondary wound with 28awg wire
running at 120 bps, I began to get racing sparks when the sparks reached
about 56" or so.  I don't remember if I experimented with higher bps with
that coil.  I don't know of any tests that anyone ever did to compare
how a given coil stands up to low bps vs. high bps, for a given spark length.
I would think that high bps might tolerate a smaller toroid size also for
a given spark length, because the high bps should be able to create
longer sparks via bang-to-bang spark growth compared to a lower bps
coil for a given input power.  I don't know of any tests that were done 
specifically to test this idea.  (one of the things I never got around to
testing).  

Richard Hull's Nemesis secondary was 14" x 46" I think, and he
got 15 foot sparks.  But it probably could have given longer sparks
if he had the space since the secondary didn't show any signs of
breakdown.  He was operating at around 400 bps probably.  

Cheers,
John

 

 


 

 

-----Original Message-----
From: Scott Bogard <sdbogard@xxxxxxxxx>
To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Sent: Mon, Jul 19, 2010 5:06 pm
Subject: [TCML] max performance per secondary diameter/resonate inductor.


Greetings all, 
   Ok finally got my 4-inch coil back up and running after a year, got sick of burning out MOTs and decided to use only two (surprisingly my spark gap manages Ok despite being less than a work of art.)  Current results is 54 inch max spark frequent strikes up to 51 inches (a personal record for me using a coil this small, and a record for my efficiency by Freau number of all my coils so far) now I'm space limited unless I roll it outside so I'm fairly pleased with the performance, half the voltage, assuming double the current, twice the arc length. Anyway my question is this, is there a table someplace that will demonstrate the longest practical arc-length per secondary diameter, I don't think I can expect to get much more out of one this small, let alone using only 4kV input and a cap way to small for resonate (I have to be running nearly 700-800bps to get the results I do.)  

 
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