Capacitance Questions

To: "'Tesla List'" <tesla-at-pupman-dot-com>
Subject: Capacitance Questions
From: Tesla List <tesla-at-stic-dot-net>
Date: Mon, 2 Mar 1998 23:54:19 -0600
Approved: tesla-at-stic-dot-net

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From:  D.C. Cox [SMTP:DR.RESONANCE-at-next-wave-dot-net]
Sent:  Sunday, March 01, 1998 5:59 PM
To:  Tesla List
Subject:  Re: Capacitance Questions

to: Jim

With this size coil you might want to start with a 12 x 3 toroid.  A good
idea is just use approx 20 turns of scrap house 12 AWG wiring on a simple
edge cut (slots) cardboard holder with a 1/4 inch spacing.  Scrape taps on
each turn and stagger them so them are not in alignment and flash over. 
Using this you will be able to quickly and inexpensively determine the
correct number of turns which work best with your xmfr-cap-secondary setup.
 Later, you can make up a real nice looking primary using plastic (delrin
or PE) holders and toss away the test setup.  The .005 value will work good
with your 30 ma supply xmfr.  You might be able to go to a slightly larger
toroid later but some toroids are so large that they really don't start to
breakout until your variac is above 60-70%.  This produces a longer spark
but a smaller toroid actually has a "neater" spark effect as they breakout
at a lower voltage and the sparks tend to "dance around" a lot more -- and
you get multiple sparks eminating from the top of the toroid.  Keep your
toroid very close to the top turn of the secondary coil -- usually 1/2 inch
which will prevent corona formation on the uppermost winding.  With this
small current a simple 2 gap sparkgap either with or without a small
100-150 CFM blower will give you a nice spark output. You can test the
blower effect by using a small shop air compressor with blow tip to
determine if the blower will effectively increase your output or if it is
not work the effort to install the blower.  Good luck and have fun.  Be
sure to unplug the xmfr as you make each primary adjustment -- time
consuming but safe!

DR.RESONANCE-at-next-wave-dot-net
  

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> From: Tesla List <tesla-at-pupman-dot-com>
> To: 'Tesla List' <tesla-at-pupman-dot-com>
> Subject: Capacitance Questions
> Date: Sunday, March 01, 1998 9:32 AM
> 
> 
> ----------
> From:  Dsurfr [SMTP:Dsurfr-at-aol-dot-com]
> Sent:  Saturday, February 28, 1998 4:55 PM
> To:  tesla-at-pupman-dot-com
> Subject:  Fwd: Capacitance Questions
> 
> I would like some advice on sizing my toroid. I have a 4 1/2"D. x 22"L.
> secondary of 24 gauge wire powered by a 15K 30ma neon xformr with a res
freq
> calculated at 357.04 hz. WinTesla says my ideal xformr to cap match is
> .0053uf. What size toroid should I be making for maximum spark. Also can
I
> increase my tank capacitance (which I think will increase my energy
transfer &
> thus spark output ?) without risking damage to my xformr? To get my
system in
> tune I think I will  have to increase the tap on the number of turns on
my
> primary once I add the toroid?
> Any advice will be much appreciated.      Jim
>