Re: Practical limit to number of turns on primary ? ? ?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Emil J. Schauer by way of Terry Fritz <teslalist-at-qwest-dot-net>" <eschauer-at-adelphia-dot-net>

John,

What do you mean by surge impedance? Is that different than the old Z of
an inductor?

Emil


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, January 27, 2003 9:41 AM
Subject: Re: Practical limit to number of turns on primary ? ? ?


 > Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<FutureT-at-aol-dot-com>
 >
 > In a message dated 1/27/03 1:34:26 AM Eastern Standard Time,
 > tesla-at-pupman-dot-com writes:
 >
 > Steve, all,
 >
 > I've found the best efficiency when using a rather large number
 > of primary turns on a small coil.  For example my old research
 > coil used about 18 to 22 turns, and gave 42" sparks from a normal
 > 12/30 NST.  By using a lot of primary turns, the surge impedance
 > is raised, and the gap losses are reduced as a result.  Also, coils
 > with a lot of primary turns probably also have a lot of secondary
 > turns, and this tends to result in a coil which operates at a low
 > frequency.  There is evidence that a lower frequency is effective
 > in producing longer sparks also.  Using a lot of turns may be less
 > important in larger coils which tend to have high surge impedances,
 > and lower frequencies even when using fewer turns, but this seems
 > to be unknown at this time.  Of course if too many turns are used
 > on any coil, it will increase the wire losses due to the high
resistance
 > of the thin wire, and the losses will increase too much.  I discuss
 > these issues at my website
 > at:
 >
<http://hometown.aol-dot-com/futuret/page3.html>http://hometown.aol-dot-com/futu
ret/page3.html
 > click on the link for "efficiency theory".
 >
 > John
 >
 > >A friend of mine made a coil with about 24 turns.  It had 2 12 turn
 > >primaries in series.  I think he used 21 turns of it. The coil used a
12/60
 > >NST, RQ gap, 4.5" x 24" (28awg) secondary, a 4.5"x18" toroid.  One
special
 > >note is that he uses for his MMC the cornel dubilier 940C, NOT 942C
caps.
 > >They are rated .15uf at 2000v.  I was worried when he said he bought
them,
 > >he didnt know there was a differece. But surprisingly, they worked
 > >extremely well!  Though we didnt run the coil for too long yet.  The
coil
 > >made 38" sparks, and the coil seemed exceedingly wild in behavior.  I
dont
 > >know that he really lost any efficiency, but i think he gained
 > >some.  Compared with other coils of the same input, and spark gap,
there
 > >was an increase in spark output of about 6" at least, and the coil
appeared
 > >more powerful overall.
 > >So maybe 18 turns isnt a bad thing!
 > >
 > >Steve Ward.
 > >
 > >
 > >
 >
 >
 >
 >
 >