Re: Formless secondaries

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

Original poster: "K. C. Herrick by way of Terry Fritz <teslalist-at-qwest-dot-net>" <kchdlh-at-juno-dot-com>

Mark-

G'day yourself!

Let me say I think the formless-coil notion is a good one.  As to
space-winding, I wound two secondaries that way.  I first wound a
sonotube tightly with cotton twine, then wound firmly over the twine a
layer of wide "plumber's tape" (very thin teflon tape used for making
pipe threads liquid-tight).  I then wound the wire over the teflon,
keeping it in the spiral groove formed by the twine.  The teflon acted to
press down the fuzziness of the twine.  The twine being of larger
diameter than the wire, the result was a coil with spacing.

For a formless coil, perhaps you could split a form as you describe, and
then wind a tight layer of twine over that and varnish it thoroughly.
Then cut the twine along the split.  Then when you wind the wire over it
and lightly fix the turns as you describe, they will end up spaced.
Possibly you would need to utilize alignment pins in the form to keep the
spiral at the split accurately aligned.

You might look into a product called Q-dope, or the like.  It's liquid
polystyrene & dries by evaporation of the solvent.  I suspect that it has
just about the best electrical characteristics of anything available.  I
used it to fix the turns on one of my coils (with a form) by just running
8 beads of it down the length of the coil.

Regards,

Ken Herrick
California

On Tue, 11 Mar 2003 07:45:05 -0700 "Tesla list" <tesla-at-pupman-dot-com>
writes:
 > Original poster: "Mark Snoswell by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <mark-at-cgCharacter-dot-com>
 >
 > G'day ... just thought I'd come out of the dark and start letting
 > people
 > know what I've been up to.
 >
 > It's been almost 28 years since I made my last Tesla coil -- that
 > was
 > back in 1975 or so... won a physics scholarship for doing it to
 > ...
 > Back then there was little more than the published works of Tesla
 > really. Now there is tons of information -- some quite solid
 > information
 > also... and the materials available are better -- as are my
 > resources :)
 >
 >
 > anyway... Just setting up again and doing a little testing of
 > secondary
 > winding techniques. I just wound two 4.5" x 25" coils with 0.6mm
 > magnet
 > wire... gonna wind a few more yet for testing. (bloody spelling
 > chekker
 > wanted to change gonna to gonad ! -- need to add Australian slang to
 > the
 > checker some time)
 >
 > The first was regular one on PCV pipe - coated with solvent based
 > polymer -- pretty normal.
 >
 > The second one (well the third actually as I did a short test one
 > to
 > test the formless method) is almost finished -- the second coat of
 > 2
 > part resin is just drying. Removing the coil from the form worked
 > surprisingly well.
 >
 > OH... and as to how you remove the form - simple. You just slot the
 > form
 > (cut it lengthwise) and insert a spacer when you are winding the
 > coil. I
 > use a 3mm spacer. After winding the coil and coating it (single
 > light
 > coat of 2 part resin) you can easily remove the form.
 >
 > The coil is very stiff and strong in its own right and there will be
 > no
 > need to use any additional support.
 >
 > ...anyway. Just thought I'd let people know that it seems pretty
 > easy to
 > make formless coils and they appear to be very stable physically. I
 > will
 > post pictures in a bit (week or so) -- when I reactivate the
 > personal
 > part of our web site.
 >
 > I do have a question -- does anyone have any really good
 > comparative
 > empirical data for different polymer and resin coatings --
 > dissipation
 > factors?
 >
 > I will measure Q's of various coils and publish the results -- soon
 > I
 > hope.
 >
 > I am also setting up my coil winding jig to wind future coils with
 > a
 > space between the turns (optionally). Most of the top potential
 > generated is due to resonant rise of potential in the secondary
 > circuit
 > -- It's funny that we see so much activity on the power supply side
 > when
 > it would appear that there are significant gains (several fold?) to
 > be
 > made by improving the Q of the secondary circuit. -- Take a close
 > look
 > at the Q Variation Experiments at
 > http://www.abelian.demon.co.uk/tssp/qvar070402/
 > The peak Q from the various coils varies by 200% or so with the best
 > Q's
 > up around 20 in that report.
 >
 > That's all for my first serious post to the list.
 >
 > Se ya!
 >
 > Mark
 >
 > ---------------------------------------------------------------
 > Dr Mark Snoswell.
 > Creator & Head Dude                        www.cgCharacter-dot-com
 > Contributing Editor Design Graphics.  www.designgraphics-dot-com.au
 > Adelaide, Australia
 > ----------------------------------------------------------------
 >