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Re: Primary coil
In a message dated 97-01-16 00:43:07 EST, you write:
<< Folks -
Could anybody point me to instructions for building a primary coil (there
is lots of info. floating about regarding the secondary coil, but I don't
recall so much for this portion of the circuit.) I've read many references
to 3/8 copper tubing, half-inch spacing with a 30 degree bank. Why?
Any help is greatly appreciated. Thanks,
Aaron Datesman
>>
Aaron,
I am not aware of any instructions. The primary design depends on how big of
a system you are building. The rule of thumb I have heard is to build a
saucer shaped primary for small coils <=1.5 kva and use a flat spiral for
larger systems. Having said that, I have a saucer shaped primary on my big
coil (6.0" dia secondary and 5 to 7 kva power supply) and a flat spiral on my
small 3.0" dia secondary system. The 6.0" coil started out with neon sign
transformers for power and gradually moved up to a pile of them and then to a
pole pig. Had I know that in the beginning, I would have built that primary
in a flat spiral also. The conductor size and spacing is pretty much
determined by the power and voltage involved. I used 3/8" copper tubing with
3/8" spacing on the large system and #10 solid copper wire with .45" spacing
on the small coil. I really should have used 1/4" copper tubing for this
primary.
Now that I have built them both, I would use a flat spiral for any size
standard spark driven Tesla coil. Even with the flat primary on the small
coil, I get coupling tight enough to see the blue corona field between
primary and secondary. As I raise power, I will probably have to loosen this
coupling somewhat by raising the secondary.
Ed Sonderman