Re: First light for an old coiler

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Esondrmn-at-aol-dot-com>

In a message dated 11/14/01 6:50:11 AM Pacific Standard Time, tesla-at-pupman-dot-com
writes: 


>
> Follow up to my previous posting. As you may recall from my earlier post the 
> 16 inch high test secondary was severely over-coupled leading to serious 
> dancing arcs across the surface of the secondary. Happily the 36 inch 
> secondary coil in exactly the same configuration shows none of this 
> behavior. With no tuning or adjustment I achieved 21 inch arcs to a grounded 
> object and 12 inch breakout was seen on the toroid. I am hoping to double 
> this with tuning and higher power settings. 
>
> I do need some advice on setting my SRSG up. During my very short test 
> firing with the SRSG I opened the static gap to about an inch and the static 
> gap still fires continuously. Although I could see the SRSG was firing as 
> well, I am assuming the SRSG is not yet correctly phased. The SRSG has a 
> total gap of about .25 inches so it should present a much lower resistance 
> when the electrodes line up. When the SRSG is correctly phased will the 
> static gap cease firing? What is the suggested gap distance for a static gap 
> in parallel to the SRSG? 
>
> Coil Specifications: 
> 20 amp Variac 
> 3 x 15 KV at 30 ma Transco transformers 
> 140 uf PFC capacitors 
> Standard neon protection circuit (RC with grounded saftey gap - less MOVs) 
> 1800 RPM SRSG using four .095 inch Thoriated Tungsten electrodes with a 
> static gap in parallel 
> .03 uf at 70 KV Maxwell capacitor bank 
> 13 turns .25 copper tubing primary currently taped at turn 9 
> 6 inch PVC with 36 inches of #22 wire secondary 
> 24 inch spun aluminum toroid 
>
> Note regarding the coil winding and coating. The coil came together in less 
> than an hour with my manual winding jig. I cannot say coating was as easy; 
> in fact is was an aesthetic disaster. Having successfully use spray 
> polyurethane on the test coil I was determined to get a thicker coating on 
> the new coil and attempted painting the coil with exterior polyurethane 
> while the coil was still mounted on the winding jig. At first everything 
> seem great but I soon found without continuously turning the coil in the jig 
> I had a serious drip problem. The net result was a very bumpy coating which 
> fortunately has no impact on performance. In hindsight I think a rotisserie 
> motor (or similar slow motor) would permit a dripless even coating. 
>
> Dave 



Dave, 

When the synchronous gap phase angle is properly set, the static gap in
parallel with it should not be firing.  I believe my safety gap is set to about
.40".  I am using a 14.4kv transformer running at about 7 kva.  The safety gap
does not fire.  Try John Freau's remote phase control system.  It works great,
takes all the trial and error guess work out of the picture and allows you to
control the phase angle while the coil is running.  I can switch between 120
and 240 bps while the coil is operating.  My synchronous gap fires through four
gaps.  Each is set to about .020". 

Ed Sonderman 

Ed Sonderman