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Re: A little design help



Original poster: FutureT@xxxxxxx In a message dated 6/14/06 3:07:24 PM Eastern Daylight Time, tesla@xxxxxxxxxx writes:


John,

Well, they are your torroids, so I'm guessing that your design ideas will be
in the ballpark! The information below is just what I'm looking for. The
reccomendation below of  using 12 to 15" of 28 gauge translates to 864 to
1082 turns. I'd like to use some 24 gauge wire I have, so I would have to
wrap 18 to 23" to achieve the same number of turns. As I recall, there is no
negative in a tall secondary, in fact I think it reduces the chance of a
primary strike. Is this true?


Jonathan,

Yes, it's true.  A tall secondary makes primary strikes less likely.
I measured my TT-32 coil secondary.  It's 3.25" dia x 17" tall
using #28 wire.  I think 19" for your coil might be good.  I think
I used a PVC pipe which gave the 3.25" dia.  So that might be
a good diameter to use.  I suggested 4 series gaps, but
it's possible 5 or 6 series gaps might be needed depending
on the type.  Preferably you'd want to avoid air blast or fan
cooling I suppose.  I remember one time Tim Raney made
a TC using a 4" x ~15" secondary wound with ~26 wire and
powered by (2) 15/30 NSTs.  It quenched well using a
4 or 6 section series gap.  It wasn't a pipe gap but just
flat plates, I forget what type of metal.  He didn't need any
fan cooling of the gap.  He used beer bottle caps.  Of
course I'm not recommending beer bottle caps.  MMC's
are very good.  I don't know what cap value Tim used.
He used a 4" dia. metal ball as a topload.  He used #8
stranded PVC ins. wire for a primary I think.  The coil gave
about 21" sparks.  He built the coil back in around 1991.

John


I will make the primary from 1/8" refer. tubing as you suggest. I'll have to
look at the caps available for MMC's these days, I plan to go that route.

Thanks for the help!!

Jonathan