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Could anybody PLEASE help me???
Hi!
This is the second time I am posting this message. Last time no one
replied and I haven’t made any progress since than on my Coil. Since the
answers to these questions are vital to my progress, I urge anyone with
the time and knowledge to answer this to do so...
---Sorry for the long message, but PLEASE read on---
Ok. My design aims for a medium power, very reliable, as efficient as
possible, good-looking Tesla Coil. I'll be tapping its energy to conduct
electromagnetic repulsion, confinement and acceleration of plasma, so
ground strikes shouldn't be much of a problem.
The main thing I am looking for here is efficiency. I want this coil to
be as efficient as possible. Therefore I've given it a 3:1 H/D ratio and
an angled primary, together with the use of 0.60 (between AWG 23 and
22) wire (any thicker would be seriously wasted by "skin effect")
Well, here are the specs for my coil so far:
Secondary:
Coil form:
Diameter: 20cm (8in)
Winding Length: 60 cm (24in)
Total length from toroid bottom to secondary bottom: 80cm (32in)
Wire gauge: 0.60mm (between 23 and 22AWG)
Spacing between turns: NONE
Secondary turns: 1000
Secondary wire length: 627.69m (2028.57FT)
Approximate resonant frequency: 186.11KHz
Secondary quarter wavelength resonant frequency: 119.49KHz
Secondary self-capacitance: 12.84pF
Toroid capacitance required to form quarter wavelength coil: 18.31pF
Primary:
Primary capacitance: 0.0127uF
Primary resonant frequency: 119.49KHz
Primary conductor diameter: 8mm (0.320in)
Primary turn to turn spacing: 8mm (0.320in)
Spacing between the secondary and inside turn of primary: 55mm (2.2in)
Primary tapped between turn 14 and 15 to form a resonant circuit at
119.49KHz
Neon transformer/Capacitor matching (not decided yet):
Transformer input voltage: 220V
Transformer output voltage: 15KV
Transformer operating frequency: 50Hz
Transformer output current: 60mA
Ok. Now the problems begin:
1- I have 2 ferrite cores, such as those used in radios. They measure 14
x 1cm (5.6 x 0.4in) and I also have 60 meters of 0.60mm (AWG 23/22)wire,
left from the Coil. Can I wind 2 good chokes using them? Would I need
more? I can get more of them, or a different wire, but no different
ferrite cores. How much inductance would be ideal for my coil? I think
2mH should do, but I could be wrong...
2- Mike Hammer suggested I used the following primary: 18 turns of 8mm
(0.320in) thick copper tubing spaced 8mm (0.320in) from each other, and
with 3cm (1.2in) clearance from the secondary and a 15 degrees angle. I
agree that's a better option, but I am not sure if it's the best option.
I feel I can make the secondary/primary clearance less. Perhaps 0.5in if
I insulate the primary (the secondary is already very well insulated
with epoxy and PU sealer). And, such a primary would have a diameter of
about 80cm (32in). That's HUGE!!! It would need such a massive base. Is
that really the best configuration, or can I make the primary coil
smaller and therefore increase inductance? I want the most efficient
design, remember!
One idea I had was giving the turns some 1mm spacing, and having 2 cm
clearance from the primary to the secondary. I would than insulate the
space between the turns and between primary and secondary with
Plexiglas, and also insulate the top of the primary and the bottom of
the toroid with Plexiglas. Would this work? Would it be a more efficient
coil? What is the ideal primary for my secondary, using power levels
between 1 and maybe 3KW?
3- Here in Holland the largest transformers available (because of legal
restrictions) are rated 8KV/50mA. I've being to all 13 Neon Shops within
a 50 KM range (it took me 5 days) and NOT A SINGLE ONE OF THE WILL GIVE
OR SELL ME A USED TRANSFORMER. Let alone the 3 I would need to run my
coil. A single new transformer here costs 300 dollars (rated 10KV,
100mA. They come from Italy and are impossible to get without and order)
Can some kind soul sell me a 1000W+ working, used neon transformer?
PLEASE!!! I really need this, and there is no other way I can get it.. I
can pay some 25 dollars plus the costs of transportation
Thank you very much for taking your time and reading such a long
message (supposing you didn't just scroll down looking for the "delete"
button). Please help me if you can... Any questions, comments, hints are
very welcome.
THANKS!!!!
Sam Barros
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