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Re: First Coil Design (fwd)



---------- Forwarded message ----------
Date: Sun, 29 Mar 1998 11:36:03 -0700
From: "D.C. Cox" <DR.RESONANCE-at-next-wave-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: First Coil Design (fwd)

to: DJ

Stick with the 8 ft. ground rods.  It is very difficult to get through the
hardpan but the layer above is very dry and will not give you the best
possible ground.  Somehow work thru it -- perhaps a crude welded-on
extension to a wood drill bit driven by a 1/2 inch drill -- and your ground
will be much more effective.  Use 1/2 inch G-10 for your RSG project -- be
sure to have a competent machine shop do the work on a turntable so it is
accurate and does not vibrate.  The square flyback chokes will work fine
for the RFC -- use approx 6-8 turns and then in series with a 50 watt, 500
Ohm resistor (Digi-Key Electronics) just before your xmfr terminals for
added protection.  Be sure to use a ball bearing motor in your RSG -- less
endplay then a sleeve bearing motor -- the sideways motion could result in
a rotor explosion.  On your RSG try 10 electrodes on a 11.5 dia disk with
electrodes at 10.5 dia.    If you don't want to mess with salt water caps
and want lighter weight to move your creation around (portable) we
manufacture some .005 9kV caps (will work at 12 kV for short duty cycles)
than are very small 1/2 x 1 x 3 1/2 inches for $25 per cap.  You could also
put them in series-parallel for the 12 kV xmfr.  Very light -- approx 4 oz
per cap.  Hope this helps out.

DR.RESONANCE-at-next-wave-dot-net    

  



----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: First Coil Design (fwd)
> Date: Saturday, March 28, 1998 10:33 PM
> 
> 
> 
> ---------- Forwarded message ----------
> Date: Sat, 28 Mar 1998 06:31:18 -0800
> From: djQuecke <djQuecke-at-worldnet.att-dot-net>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: First Coil Design
> 
> Well, I've spent a couple of months collecting most of what I need for my
> first coil.  I've tried several of the Tesla programs (and generally come
> close to the same answers <g>).  I thought I'd float my plans (and
> questions) for this first coil and see if I'm close.
> 
> I have one 15k, 30ma, 115v, 60hz neon transformer and intend to add a
second
> soon.
> 
> With one tranny, I'll need .0053uf and with two, .0106uf for the tank
> capacitors?  I'll try saltwater, poly/flash in oil and I'm working on an
> experimental design (aren't they all <g>) using a product called ALPOLIC
> I've mentioned on the list several months ago.
> 
> Secondary is approx. 4.2" diameter and I'm figuring 21" tall (5 to 1).  I
> haven't wrapped it yet, though I've built a crude motorized "lathe" (PVC
> <g>) and have started sanding on a 36" PVC pipe.  I've got 1000' of 22
gauge
> magnet wire and a gallon of oil based polyurethane.  I'm figuring about
790
> turns of wire at 37.5 turns an inch and about 840' of wire used.
> 
> Primary is 1/4" copper fridge tubing, inverted saucer, 1/4" spacing, 15
> turns (or however far 50' gets me <g>).  I'm not certain about lateral
> spacing of primary and secondary.  I'm taking a shot at 5/8" space
between
> secondary and inner coil of primary??  Inductance figures don't seem to
add
> up??  Best spot to start tap?
> 
> Secondary base is easily adjusted vertically to optimize coupling.
> 
> I've built a safety gap using 3/4" x 1.5" brass rod on 3/8" threaded
brass
> rod in a nylon base.
> 
> I've built a similar spark gap with attached airblast for main spark gap.
> I'll also try a couple of 6" RQ cylinder gaps.  I've acquired a motor, (a
> 1/2hp Dayton with a variable speed drive, 705-4230rpm), bearings, etc for
a
> rotating sparkgap but have had trouble locating the G-10 (same as
GAROLITE?)
> material for a disk.  The locals don't have a clue so far.  I've seen it
in
> McMaster's.  Any other (cheaper) mail-order sources for a 10" - 12" disk
or
> a 10" x 10" - 12" x 12" sheet?  Best thickness??
> 
> Toroid constructed from 4" aluminum flex, pizza pans and aluminum tape. 
I
> have yet figured diameter.  Would seem that the goal for me would be to
try
> to get secondary freq. down from approx. 515kHz range to the 250kHz
area??
> 
> I have a 5a STACO variable transformer. (Large enough?)  I have access to
a
> 10a if necessary.
> 
> Four 8' ground rods.  Any problem with cutting them in half and going
with
> eight 4' rods?? (Hardpan about 5' below surface)
> 
> I still need to figure PFC??  Seems to be contrasting arguments over the
> need for this?
> 
> I need to build chokes.  I saw a thread on using the cores from flybacks.
 I
> have several such cores at 4" square by 1/2" diameter.  Is this viable?
> 
> What changes will be necessary when going from 30ma to 60ma with a second
> (or third) tranny? (Besides capacitance of the tank circuit...)
> 
> Cheap source for high voltage wire?
> 
> Sorry this is so long but I tried to include all necessary info (as well
as
> fish for some answers <g>).
> 
> As my first coil, I want to try as many different methods in constructing
> each part, hence the different capacitor types, spark gaps etc.  My
thought
> is to try and keep as many parameters as possible variable for
optimization
> later (variable speed motor, secondary height, primary length, etc).
> 
> Anything obvious I'm missing here?
> 
> Thanks for your time,
> 
> dj