David,
72" WOW as I have similar specs but only get 36-48" or so.
Here are my specs:
15kv, 120ma <-- Same (2 15kv 60mA NSTs)
3 levels of 0.010uf in parallel for 0.030uf mmc (30kv) <--- Seems like
your double of what mine is
2 parallel tungsten gaps "about" 1/4" separation each (with a squirrel cage
fan blowing on them) <--- *Should these be tighter since there are 2 of
them? (i.e. 1/8" inch each)*
Secondary - 6"dia x 31"lg 1400 turns No. 24
Top load - 6" x 25" aluminum dryer ducting and foil pizza pans with foil
wrapped cardboard between and nylon toilet bolt <-- NOT wrapped in 3"
aluminum tape
(Would wrapping this improve the length significantly). I have the
materials for an 8" aluminum dryer ducting, aluminum tape, 17.75" x 1"
circular wood table (to be wrapped in foil and then glued and possibly
aluminum taped). *Should I just wrap the 6" more flimsy version or go with
the bigger 8" more solid heavier version (to construct) - OR use both on
top (wrapped/unwrapped in aluminum tape)?*
Primary 0.25" copper refrigerator coil in single layer tapped at 12.5 turns
I was thinking of the rotary gap motor version for the spark gap but have
no idea where to even start on this. I was hoping to get everything the
best I could first before and if I go down that route.
*So what has the greatest impact on spark length - the rotary spark gap or
the wrapped aluminum tape on the toroid - or are both necessary?*
Thoughts?
Tim
On Mon, Apr 6, 2015 at 8:56 PM, David <zipo@xxxxxxxxxxx> wrote:
Timothy, List - I too have recently put together a 15kv, 120ma coil. I'm
still tweaking for best out put. So far I'm getting 72" output and based on
the way it was running and the way it was tuned I believe it will do at
least 80" after it's fully peaked. I can only run outside so I'm having to
wait for good weather.
Here is a brief over view:
15kv, 120ma
.0625uf mmc
sync rotary gap @ 120 breaks/sec
secondary - 7"dia x 27.3"lg 1500 turns No.26 wire
Top load - 5" x 20" spun aluminum toroid
primary - 10 turn 2 layer spiral
Tesla equi drive circuit.
There are two aspects of tuning and peaking that seem not to get the
attention that they should (in my opinion).
First is that if tuning with a signal generator and a oscilloscope you
need to simulate the added capacitance of the spark. Adding a piece of wire
the length of the spark your expecting to the top load and then tune with
sig gen and o scope. This seems to be overlooked a lot. Java TC shows this
very well. If you ad an additional cylindrical top load, on JTC, .02dia x
length of spark (JTC will point it straight up) you will see a marked
reduction in res. frequency.
Second is that the safty gap or static gap width has a large impact on
output. There are way of setting these gap for safest operation. However
I'm guessing these gap widths get pushed a bit by savvy coilers but don't
talk about it. At least on a sync rotary safety gap width has a big bearing
on output. I would find it very interesting to hear what gap width people
are using with what setup. And in full disclosure :) I have set both of my
safety gaps at .22 using rounded brass draw pulls for electrodes.
It just seems to take a lot of time to get every thing tweaked to
Perfection.
Carry on
David
On 4/6/2015 9:34 AM, Timothy Gilmore wrote:
Has anyone put together any sort of a listing of others Tesla Coils built
with parameters listed such as:
(for example): I have 2 NSTs (15kv, 60ma) each, 6" diameter, 31" high
secondary, torroid is ....
I am getting 3-4' sparks and wondering if I should be getting longer
sparks. Is this normal? or should I add another NST or bigger Toroid
(working on an 8" diameter ducting bigger one). How do I know since the
Tesla Map software says I should get "ideally" 72.6 inch sparks and I'm
getting about 1/2 to 2/3 of that. Just wondering if it's not tuned
properly
(but I think it is) - or making a larger toroid is worth the effort if
I'll
gain a foot or more sparks.
How does one know they are getting close to the best they can get in spark
length?
I have attached my Tesla Map file of current settings.
Thanks,
Tim
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