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Re: Figure this out.

Tesla List wrote:
> 
> Subscriber: gweaver-at-earthlink-dot-net Mon Jan 20 22:03:01 1997
> Date: Mon, 20 Jan 1997 10:41:06 -0800
> From: Gary Weaver <gweaver-at-earthlink-dot-net>
> To: tesla-at-pupman-dot-com
> Subject: Figure this out.
> 
> Figure this out.
> 
>   [ Part 2: "Attached Text" ]
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> Can someone explain this.  I have 3 neons in parallel.  The power supply is 15KV 90 ma.  The maximum spark length at the secondary is 44".  I added another neon making the power supply 15K 120 ma.  The maximum spark length at the secondary is still 44".
> 
>   I added another neon making the power supply 15K 150 ma.  Now the maximum spark length dropped to  39".   With more power the output gets smaller?
> 
> The secondary is 1064 turns of # 24 wire on a 7" PVC pipe.  The primary is 3/8" copper tubing spaced 3/8" between tubes 6" inside dia. 30" outside dia. 30 degree helix wound 18 turns tapped at turn 14.  The capacitor is .008 uf rolled polyethylene oil f
> 
> illed.  The RQ spark gap is 8 gaps .030 each fan cooled.  2 chokes 2.5 uh each wire resistance 1.1 ohms.  Toroid is 2 stainless metal bowls 12" dia.   2 safety gaps .250 gap from HV terminal to the transformer case ground.
> 
> Using power supply 15KV 90 ma I added another choke (100 uh 10.5 ohms wire resistance) in series with the 2.5 uh choke.  Total 102.5 uh 11.6 ohms.  The output was reduced from 44" sparks to 39" sparks.
> 
> Using power supply 15KV 90 ma I added another choke (190 uh 18 ohms wire resistance) in series with the 2.5 uh and 100 uh chokes.  Total  292.5 uh 28.5 ohms.  The output was reduced from 39" to 30".
> 
> I removed all 3 chokes on each HV terminals and the secondary spark output is 44" using 15K 90 ma power supply.  I added a 10 ohm resistor to the HV terminals where the chokes were and the output was reduced from 44" to 40".   The output with a 10 ohms
> 
> resistor is about the same as with 11.6 ohms wire resistance using 2 chokes.
> 
> Using power supply 15KV 150 ma I added another .008 uf capacitor in parallel with the other .008 uf capacitor.  Also using all 3 chokes in series on each HV terminal.  The secondary output sparks got much hotter and much louder but not longer.  Output i
> 
> s 30" sparks.  The 3 chokes in series are physical spaced 2" apart.  Sparks are jumping between all the chokes and also threw the choke windings.  1 neon shorted out and had to be replaced.  Tried again and another neon shorted out and had to be replace
> 
> d.
> 
> Both neons transformers that shorted were Franceformers.  Both transformers shorted only on one side.  The side that shorted was the capacitor side of the LC circuit.  They were both in the exact same location among the 5 transformers that were in paral
> 
> lel.   With the transformers in 1, 2, 3, 4, 5 order and the spark gap in parallel with transformer # 5 it was the # 1 transformer that shorted out.  The safety gaps were connected across transformer 5.  The LC circuit is connected across transformer 5.
> 
>  The spark gap is connected across transformer 5.  It seem logical that any RF or HV feedback from the TC would reach transformer 5 first where all the safeties are connected.  Transformer # 1 is the farthest away them the safeties.  What ever caused tr
> 
> ansformer # 1 to short had to pass 4 other transformers to get to # 1.  I moved both safety gaps from transformer 5 to transformer 1.  Replaced transformer 1 and tried again.
> 
> Again transformer # 1 shorted out on the capacitor side of the LC circuit.  Another Franceformer brand.
> 
> I replaced the bad transformer.  Reduced the safety gaps from .250 to .187.  Moved the RQ spark gap from transformer 5 to transformer 1.  I still have all 3 chokes in series with the LC circuit and connected to transformer # 5.   Try again.  After about
> 
>  10 seconds transformer # 1 shorted out but this time not on the capacitor side of the LC circuit. This time I fried a Jefferson Electric transformer. An arc struck the spark gap fan motor and shorted it out too.   I'm not having very good luck.
> 
> It must be the capacitors.  Too much capacitance?  I didn't have this problem with 1 capacitor.


Gary,

The input power levels you're running at are exceeding the
power-handling capability of the Richard Quick type static gap. The gaps
are "saturating" - the copper pipes are overheating, and failing to
quench the arc. The energy you've transfered to the secondary on each
"bang" is coupling back into the primary and being dissipated in your
gaps instad of in the streamers. Up to a point, the additional current
you get by adding transformers allows you to recharge the tank cap more
quickly to the 60 Hz HV input, and makes the gap fire more times each
each half cycle. More "bangs per second" _will_ increase streamer
length. However, once you've got enough input power to consistently
re-charge the caps, any additional input power will not add to output
sparklength, since you're now limited by the amount of energy the tank
caps can store each "bang". Once you reach this point, you'll need to
increase the tank cap size. 

Near-term, to increase spark length on your system, you'll need to first
go to a better quenching high-power gap, such as either a vacuum or
air-blast type gap. Increasing the tank cap size will work (AFTER you've
fixed the gap power-handling problem). After quenching gap will improve
your performance at ALL power levels.

The chokes you have are not being effective, since they are breaking
down and letting VHF RF come into the transformers. VHF RF is funny
stuff... you may be seeing some standing wave activity which is
overstressing some positions (the last?) more than others. A
single-layer air-core winding on a 3" PVC coilform, say 10" long and 26
- 28 AWG on each leg should do it. A couple of series wirewound
resistors (2500 ohm at 50 Watt) can also be used to help damping. Some
coilers (myself included) also add some "lossy" capacitance in the form
of 500 - 1000 pF at 40 KV from each neon leg to the center tap to help
bypass the neons. Keep your wire-lengths short.

Good luck, Gary

-- Bert --