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Re: magnifiers

Tesla List wrote:
> 
> > > Subject: magnifiers
> > Subject: Re: magnifiers
> 
> Subscriber: mwade-at-aros-dot-net Thu Jan  2 23:11:06 1997
> Date: Thu, 02 Jan 1997 19:47:04 -0800
> From: MIKE WADE <mwade-at-aros-dot-net>
> To: tesla-at-pupman-dot-com
> Subject: Re: magnifiers
> 
> Tesla List wrote:
> Bert:
>         Thanks for the consideratoin in evaluating my system. Following is the
> additional info. which I think you may see some red flags come up upon
> evaluating.
> 
> caps: 2- basically R.H. style design rolled LDPE and HDPE totalling
> .0275uf (measured).
> primary coil: 30 deg. conical, 10 turns 1/2" refridge tubing (tapped at
> about 8) 7" i.d. , 20" o.d., 1/4" spacing.
> secondary coil: 4" dia., 22" high, 24ga.
> pwr. supply: 1- 12kv. 30 ma. neon
> toroid: 27" o.d., made from 5" AL flex duct and spaced 7" from top of
> coil form.
> Gap: single static air blast -at- about 1/2" setting
> 
>         As far as tuning, signal generator input to sec. shows resonant freq.
> to be same as o scope observed freq. that the pri. is running at- is
> this a valid analysis technique?
>         I have been playing with decreasing the coupling by raising sec. up
> away from pri. with little if any change. Had not thought toroid spacing
> heigth mattered much in operating characteristics- thought technique was
> to just raise it high enough so no discharges occur to pri. circuit. I
> have no trouble getting discharge to free air as is, and adjustments to
> pri. tap show very noticeable changes in discharge.
> 
> Hey, I'm really with 'ya as far as  meaningless pseudo- science out
> there! I am thankful for this great forum to exchange repeatable,
> observable studies in this area! You're right about time passing when
> things are running smoothly!
>         Thanks, and I look foreward to your analysis.
> 
> Mike
> 

Mike,

Thanks for the additional info. 

General comments:
The first problem I see is that your 12 KV 30 MA neon is heavily
overloaded by the tank cap. This transformer is optimally sized for
about 0.0066 uF, and could drive up to 0.01 uF - but 0.0275 uF is much
too big. Based upon the size of your secondary, toroid, and primary it
does look like you're in the right ballpark from a tuning standpoint.
However, the use of 1/2" copper tubing is larger than necessary for a
coil this size, and, combined with only 10 turns, results in relatively
low primary inductance, forcing the need for large tank capacitance to
bring the system into tune. Your system is basically starved for power!
Also, the static gap spacing of 0.5" looks a little bit long for a 12 KV
transformer.

The tank cap you've got would be ideal for a 120 MA source, but is
necessary for system tune with your existing primary. If you can get
them cheap, go for it... there's no substitute for power. However, the
secondary may not be able to handle this level of input power unless you
reduced the gap spacing a bit, and the added current may also strain the
quenching capability of your air blast gap. If you are not already doing
so, you may need to use compressed air in a true air-blast configuration
to quench.

Near-term, I'd suggest removing one of the caps, and adding one more 12
KV 30 in parallel to better match the smaller tank capactitance. Also,
reduce the gap spacing a bit. With 0.0138 uF and two 12 KV 60's you'll
be close to 60 Hz resonance. Don't open the gaps too widely - you WILL
blow the weakest link (usually the neon, but sometimes the tank cap).
You'll also need to reduce toroid capacitance to bring the system back
into tune. Try using a pair of pie-pans, and 4" aluminum dryer duct to
make a 15" x 4" toroid, and reduce the toroid-to-secondary spacing a bit
to compensate for the reduced shielding and to reduce the toroid's
isotropic capacitance a bit. Retune the system via the signal generator
and oscilloscope - you should be able to regain tuning by moving the tap
closer to the outermost turn. 

Use a nail or screw point-up on the toroid to adjust high power tuning.
BTW, if you don't already have one, be on the lookout for a variac.
You'll need it to better ramp up and control the power.

Good luck, Mike - Keep us posted on how you're doing!

Safe synergizing to ya!

-- Bert --