Recommendations for Monster Coil?

To: tesla-at-pupman-dot-com
Subject: Recommendations for Monster Coil?
From: Tesla List <mod1-at-pupman-dot-com>
Date: Thu, 2 Oct 1997 09:52:31 -0600 (MDT)
Approved: mod1-at-poodle.pupman-dot-com


---------- Forwarded message ----------
Date: Thu, 2 Oct 1997 01:01:31 -0500
From: "Charles S.S. Goodwin" <goodwc-at-rpi.edu>
To: tesla-at-pupman-dot-com
Subject: Recommendations for Monster Coil?

Although I have at this point built only one (barely functional) coil, I
somehow got it into my head that it would be neat to build a really big
coil.  I have a few friends willing to help me in this endeavour, and am
looking for some design wisdom as I plan.

I formed an image in my head of a looming cylinder putting off 12 foot
streamers from the metal sphere at its top.   With the image in my head as
a goal, I want to design the apparatus to achieve what sits in my mind's
eye. Consequently, I plan to have a secondary which is about 10 or 15 feet
tall and 12 to 24 inches in diameter.  I figure I can use builders tube
(used for casting concrete pillars) for the form.  I suppose a pole pig is
in order (approximate price is...?) and I will need a large cap or bank of
caps (better to build or buy/trade for...?).  Also, for such a large coil,
which type of gap would be preferable (rotary or...?).

If anyone who has built such a monster is willing to share their
(successful?) design specs with me, I would greatly appreciate it.

By the way, I originally wanted to design the system around a cap bank
which I recently aquired.  It consists of 7 laser discharge caps.  Each is
rated at 4 Kv (non continuous) or 2.5 Kv continuous and 375 mfd.  I figured
that if I were to run them all in series, I would end up with a 53 mfd 17.5
Kv cap bank.  However, this translates to something like 30 amps at 15 Kv
(leaving 2.5 Kv of headroom so as not to overstress the caps) for a
resonant frequency of 30 khz, if my quick calculations were correct.  ;)
Even with a 100% efficient primary transformer (to simplify
calculations...), this is over 3000 amps at 120 volts (or 750 amps at 480
volts).  Hence I would need one hell of a lot more power than I would ever
be able to provide.  I don't know if a pole pig would be in order, maybe a
small city's substation transformer instead.

Since it doesn't look like an option to build a coil with these caps, does
anyone know where to get rail gun plans?

Thanks so much,
Casey

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Casey Goodwin
goodwc-at-rpi.edu

Snail Mail:
Charles Goodwin
Church I, 1001
RPI Residence Hall
110 8th Street
Troy, NY 12180

Phone:
(518) 276-4684