Re: No Subject

In a message dated 95-08-08 12:45:12 EDT, tesla-at-grendel.objinc-dot-com writes:

>You wrote:
>> My secondary is built on a 6.0" dia pvc pipe - probably 6.25" od.  It is
>> covered with 5 - 6 coats of polyurethane.  The wire is #22 formvar covered
>> magnet wire - then covered with another 6 coats of polyurethane.  I
>> the winding length is 27"  (my records are at home and I'm at work).
>> is approximate 960 turns.  Primary is 15 turns of 3/8" copper tubing wound
>> a plastic coil form at 30 degrees (saucer shaped).  Toroid is 40" in dia
>> 5 or 6" thick.  Spark gaps are one rotary with a static gap in series.  I
>> haven't checked the frequency since I built my newest toroid.  With my 33"
>> toroid, I believe the frequency was about 130 khz.
>I assume that that toroid (40"x5-6") is optimised for your system (having 
>followed your previous postings). Is the dimension simply related to the
>dimensions or is there a more complex relationship involving operating power
>and frequency etc?
>Phil Mason


As you probably already know, the primary and secondary circuits must be
tuned to the same frequency.  The primary circuit consists of the capacitor
and the primary windings, which need to have a moveable tap.  The secondary
circuit consists of the secondary coil and the toroid.

I started out with the 6.25" dia secondary and a 15 turn primary (3/8" copper
tubing).  Those two things are about the only things I have not changed.  I
started out with neon sign transformers and two .019 mfd capacitors in series
(approx .01 mfd) and a 14" x 4" toroid.  The secondary coil and its toroid
will determine the frequency that the primary needs to run at - or looking
from the other direction, the size of your capacitor and the primary will
determine what size the toroid needs to be.  As you increase the capacitor
size, you will need to increase the size of the toroid.  Increasing the
toroid size brings down the frequency of the secondary.  I have found that
you want a capacitor and toroid sized to allow the system to tune out near
the last few turns of the primary for most efficiency (bigger sparks).  You
want to be out somewhere between 12 and 14 turns.

Ed Sonderman