SGG Questions - Cliff's Notes

From:  D.C. Cox [SMTP:DR.RESONANCE-at-next-wave-dot-net]
Sent:  Thursday, January 22, 1998 5:20 PM
To:  Tesla List
Subject:  Re: SGG Questions - Cliff's Notes

to: Cliff

You must be vary careful running a non-synchro high rep rate RSG with a NST
as a power source.  The NST will usually blow with a high rep gap.  You
might consider a good solid synchro gap design firing at 120 PPS as a solid


> 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
> system? 
> Thanks,
>  Cliff :-)  (So many questions - To little time - So much to do)