Re: My Secondary
Subject: Re: My Secondary
From: "Malcolm Watts" <MALCOLM-at-directorate.wnp.ac.nz>
Date: Wed, 10 Apr 1996 16:50:35 +1200
>Received: from rata.vuw.ac.nz (root-at-rata.vuw.ac.nz [18.104.22.168]) by uucp-1.csn-dot-net (8.6.12/8.6.12) with ESMTP id WAA18327 for <tesla-at-grendel.objinc-dot-com>; Tue, 9 Apr 1996 22:50:41 -0600
On the subject of extremes I was interested to see this from Scott
> I wrapped the coil around a 4' long cardboard tube with 8.5"
> diameter. I did not paint it with any kind of finish to make it
> more of an insulator. I also made a rather larger mistake in using
> (and this is the kicker!) #34 wire. So now I have a 4' long 7000
> wind inductor and I was wondering if there is any way to make a
> working tesla coil out of this or do I just have a big piece of
> junk. Any suggestions would be grealy appreciated.
My suggestions: I would try it out of sheer interest before pulling
it apart. BUT, I think the tube should be thoroughly dried and
impregnated with varnish before firing. My guess is it would smoke at
any appreciable power level due to the thin wire insulation (volts
per turn). I calculate : inductance about 1.7 Henries!
: self capacitance about 19pF
: bare resonant frequency about 28kHz !
I would expect its Q to be moderate due to the high wire
resistance and cardboard. But I reckon there must be a hundred and one
interesting experiments you could perform with it and I would love to
hear from others who have contemplated things to do with low
Ny prime suggestion : acquire a more suitable former for a serious
coil and in the meantime, let's see what ideas there are for this
somewhat unique opportunity. For example, if you tuned it to 8Hz with
a capacitance of 233uF, you could "listen" in to the earth's natural
resonant cavity (guess). Extra capacitance of 130pF (additional to the
19pF self-C) gets it to resonate at 10kHz (within hearing range). I
must admit to wondering what a coil really sounds like :)
What do others think??