SGG Questions - Cliff's Notes

From:  Cliff Fahrer [SMTP:cfahrer-at-In-Touch-dot-net]
Sent:  Wednesday, January 21, 1998 7:18 PM
To:  tesla-at-pupman-dot-com
Subject:  SGG Questions - Cliff's Notes

First off I would like to say that I'm very impressed with the kind help
and good information that has been submitted to the Tesla List. I have
only been signed on for a couple of months and my brain has already shut
down 3 times from information overload.

My questions concern a rotary spark gap that I have almost completed.

The basic Tesla Coil system design is:

1.  Neon sign transformer mfg by Transco with a 120 volt primary and a
9000volt 120MA secondary.

2. Glass Plate capacitor in transformer oil measured at .032uf.

3. The Tesla coil has a spiral wound primary with a 6in dia inner
winding. I used 1/4 inch copper tubing with 1/4 inche spacing between
windings. The secondary is tight wound with AWG 30 copper enameled coil
wire on a 2 inch carboard tube. The secondary has 3000 turns.

Now the rotary spark gap questions:

1. The rotary spark gap is 8 1/2 inches in dia at the tip of the gap
points. I plan to use 1/8 inch pure tungston rods with rounded tips for
the gap points. Is the diameter correct? Also has anyone tried pure
tungston for the spark gaps? The Rotating disk has 8 point gaps that
operate in series.

2. Should I make the stationary points adjustable for dwell? (My next
construction step is making the stationary point assembly.) 

3. The big RSG question: (Which is probably to late at this point in
time because it is already constructed) is: I used a DC servo motor with
a solid state controller for speed control. The motor is rated at 10nm
torque continuous. The motor with the controller has been tested to run
at 3600rpm giving me 580 bps gap speed. Has anybody tried a rig like
this, or am I doomed? I plan to shield the controller and keep it at a
safe distance from the high voltage circuit. The motor case will also
have a size AWG 10 wire to a seperate ground rod.

The last question:
When the RSG is completed and if it works ok on my small Tesla coil, we
plan to use it on a 50KVA Tesla coil. Is this RSG big enough for a 50kva

 Cliff :-)  (So many questions - To little time - So much to do)