Re: The big bad Mark III

["Garry F." <garryfre-at-pacbell-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

The otimum ratio for secondaries is a height that is five times the outside
diameter of the secondary.

So, for a six inch coil, the height the wire should cover thirty inches of
the form.

I don't know if this is a hard and fast rule tho. I suspect the wire guage
would have an effect on this.

Does anyone have a formula for this ratio that take into account the guage
of wire on the secondary?



----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, August 12, 2000 8:48 PM
Subject: The big bad Mark III


> Original poster: "Troy Peterson" <highvoltage-at-mad.scientist-dot-com>
>
> Hi again list!
>
> I am about to begin scrounging parts for my 3rd tc, which I am
affectionately
> calling the Mark III (real original name eh?). There is good reasoning
behind
> this though: When I was into building Van De Graff generators it took me
three
> attempts to truly get it right. My first tc was a tiny (1.5" diameter)
coil
> that I played around with to get the feel for HV (1" streamers), my second
coil
> was a 4" diameter coil that I threw together just to see if I could make
it
> work, and now I am going to build a somewhat decent coil (I hope). Anyway,
a
> few questions.
>
>    I  was considering going to the ends of the earth and back for 2 15kv
60mA
> NSTs, but then I realized that, assuming 100% efficiency and 0% losses
this
> would draw 15A - not too good for a 15 circuit in the house :-(  In the
end it
> will depend on what I can actually obtain - I am hoping for 15kv 90mA
total at
> least. I am not asking anyone to waste their time doing the calculations
for me
> (there are plenty of programs to do that...) but can someone point me in
the
> direction of what I would be looking at in way of a cheap MMC? I am
looking for
> cheap caps that will handle the current and voltage at about 0.025 uf I
think -
> I just want to know what type of caps I should be looking at and how many.
I
> was going to go with the typical 1/4" copper tubing for my pri. coil until
it
> occurred to me today that copper ribbon would be more compact and perhaps
> easier to mount - along this line: Where could I get some? Is it cheaper
than
> tubing? does it suffer from corona problems? and how do I figure out it's
> inductance? Cost is the biggest concern (I am saving for college).
Finally, my
> planned secondary is 6" od pvc wound 24" long with #24 enameled wire, does
this
> sound ok with the above system?
> I hope to design this coil to be fairly compact so I can take it with me
when I
> leave home. My last one was huge (for a small coil), having been built
with the
> tank circuit inside a TV stand and lots of bottle caps.. Thankyou for any
help
> you can provide.
>
> Regards,
> Troy Peterson [VE7SOK]
> <mailto:troypete-at-sunwave-dot-net>troypete-at-sunwave-dot-net
> <mailto:highvoltage-at-mad.scientist-dot-com>highvoltage-at-mad.scientist-dot-com
>
>
>