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Re: It works, But I want more. (fwd)

Esondrmn-at-aol-dot-com wrote:
> 
> In a message dated 97-03-04 00:17:21 EST, you write:
> 
> << Thanks to everyone for helping get my first coil off the ground.
> 
>  Especially Mike Hammer and Bert Pool, who helped and helped and
>  helped.
> 
>  Ok, here are the specs:
> 
>  corcom rf ac filter
> 
>  5a variac
> 
>  9kv x 30ma (I have another 9 x 30 and two more 12 x 30; just limiting
>  exposure to stupidity)
> 
>  1/2" spark gap
> 
>  2" pvc x ~100 turns 22 ga. chokes
> 
>  1 1/2" copper tube x 7  -at- .028" spark gap w/ muffin fan
> 
>  60" x 14" x .093ldpe rolled cap (.007995 uf per my Radio Shack meter)
> 
>  12" id 3/8" +  3/8 clearance  x 10 turns 30 degree spiral primary
> 
>  6" clear acrylic tube x 24" (~900 turns) 22 ga. secondary
> 
>  5" x 12" drain pipe toroid (I know it's small but nothing happens with
>  the big one.)
> 
>  8 ' ground rod w/ 8ga. ground wire to base of secondary
> 
>  I get:
>         blue 15" streamers into air (they don't photograph well)
> 
>         occasional 15" white streamers to nearby grounded objects
> 
>         a few lines of interference on tv
> 
> 
>  I noticed that the primary works best wide open.  Any reduction of
>  windings reduces output. Do I need a bigger primary coil or
>  jus mo juice?
> 
>  I'm ready to try some of these other transformers.
> 
>  I know I can strap xformers of equal value, and that's next
> 
>  Now don't laugh, I can't help that I don't know any better.
>  What about strapping all 4 of my neons together:
> 
>  ----------------*|||*---------------
>                 *|||*
>                 *|||*
>  240vac    ~140 *|||*12kv 30ma * 2
>             vac *|||*
>  single  |-------*|||*-----|    =~21kv -at- 60ma
>  phase   |                |
>          |-------*|||*-----|
>                 *|||*
>            ~100 *|||* 9kv 30ma * 2
>             vac *|||*
>  ----------------*|||*---------------
> 
> 
>  of course, even if it worked, I'd need another capacitor in series.
> 
> 
>  All comments and suggestions are badly needed.
> 
>  David Christal 3341 Cloverdale Lane, Dallas, TX  75234
>  214 349-6972 (214 FIX MY PC) (Pool Cues and Personal Computers)
>   >>
> 
> David,
> 
> Sounds like a good project, about the same as my 6" coil.  I did some
> calculations on your coil.  Your are correct, you are just on the edge of
> being in tune.  I calculate the correct tune for your given parameters would
> be at turn 10.5.  If you remove the toroid or use a smaller one, you should
> be able to tune it now.  You need a .0088 mfd cap to tune it as described.
>  The best bet, if possible would be to add two turns to the primary.  This
> will give you some room to add the larger toroid.  You might also consider
> building another capacitor and using the two in parallel.  I am glad to see
> that you used .093 poly (instead of .063).
> 
> The inside dia. of you primary seems unusually large to me.  You have allowed
> 3.0" clearance from the secondary.  I think my primary is 2.0" (I.D.) larger
> that the secondary O.D. - allowing 1.0" clearance.  Of course my coupling was
> too tight and I had to raise the secondary up 2 or 3" to fix that.  I doubt
> if that is costing you much in output.
> 
> I use a .025 mfd cap, 14 turn primary (tuned about 13) and a 40" toroid.
> 
> You can parallel as many transformers as your variac can handle but they must
> all be the same voltage rating.  With a 5 amp variac, you will probably need
> to add a power factor correction cap across the primaries if you use two or
> more in parallel, to keep the variac current as low as possible.
> 
> With the two 12kv transformers in parallel, and the system in tune, you
> should be able to get about 3 foot sparks.  This coil should perform well and
> scale up just fine as you desire to add additional power.
> 
> Ed Sonderman