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Re: Latest results of 12.5" coil
---------- Forwarded message ----------
Date: Mon, 20 Oct 1997 18:19:16 -0400 (EDT)
From: Esondrmn-at-aol-dot-com
To: tesla-at-pupman-dot-com
Subject: Re: Latest results of 12.5" coil
In a message dated 97-10-18 13:18:49 EDT, you write:
<<
Catchya later!
Rod
Oh, here's the coil specs if someone feels like doing some maths :-)
(Any get the resonant frequency? How far off tune are we?)
Secondary: 12.5" 900 turns of 1mm enamel coated Cu wire, space wound at
21 turns/inch.
Primary: 5 turns of 3/8" copper pipe, spaced at 7/8", archimedes coil.
---( )------( )------( )---
^--7/8"--^
Tapped out at approx 4 7/8" turns.
Diameter: 24 7/16"
Average radius: 10 9/32"
Primary Capacitor: 0.152uF 50KV Pulse rated.
Power Supply: 11KV 5-10KVA SWER Pole-pig.
Power input: 240VAC, approx 16-20 amps. 50Hz
(Yup! out of a 10amp power outlet, luckily w/ a 20amp
breaker!)
Current Limiting: 50mH inducive ballast.
Rotary Gap: currently at 96bps, async. Will be 1500rpm 300bps soon.
Top load: approx 24"x 6" toroid, situated approx 5" above top turn of
the sec. coil.
>>
Rod,
I see that Chuck Curran ran some calculations on your coil. I also ran some
on my spreadsheet. I calculate 61.4 mh for your secondary. Resonant at 140
khz unloaded and about 96 khz with your 24" toroid. Primary is 19.8
microheneries and should tune right at 4.75 to 4.80 turns. The program
calculates this point at about 18.2 uh. I agree with Chuck, this coil could
use a lot larger toroid and would perform better. I use a 40" toroid on my
6.0" dia coil, you could easily go to 60 or 70" if you have enough power to
drive it. I think you need to get the performance up to about 6 or 7 foot
sparks before you go to the larger toroid or you might not be able to break
it out.
Sounds good so far, keep up posted on your progress.
Ed Sonderman