[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

15" coil project



Original poster: "Brett Miller by way of Terry Fritz <twftesla-at-qwest-dot-net>" <brmtesla-at-yahoo-dot-com>

Hello everyone,

I am planning on winding a 15" secondary soon for some
testing and observing some truly huge arcs.  I found
an old piece of PVC in a creek bed that is 50" long
and 15" in diameter.  I've had it for a while, but now
someone is offering to give me a "grant" of a
considerable sum of cash to fund further scientific
research.  So I am preparing to order the wire and
build a jig next week.  I was wondering if anyone had
any recommendations for wire gauge on such a large
diameter coil.  I want it to be able to be driven as
hard as I can drive it with the available power from
my house's 220V service.  I was thinking about going
with 22 awg and shooting for about 1600+ turns.  Also
was planning on using just .25" copper tubing for
about 25-30 turns in the primary at .25" spacing. 
Should I go with a larger size primary conductor or
will .25" be sufficient?  I know most people in the
past have gone with 18AWG or bigger for large
secondaries like this, and 3/8" or larger primary
copper, but in light of the findings of John Freau,
Richie Burnett, Adam Minchey, and others, I wanted to
go with more inductance, greater primary surge
impedance, and less gap losses for better efficiency
and longer arcs.  Would I be likely to limit current
to the extent of shortening the arcs (to a measurable
degree) by using 22 gauge on a secondary this large? 
I also don't want the arcs to be fainter and not as
bright due to a decrease in current to both the
primary and secondary.
I have done a few calculations, consulted several
computer programs and I do have my own predictions,
but since I will be spending quite a bit on a rather
large roll of magnet wire, I wanted to get a few of
your opinions on this.

Thanks in advance,
-Brett