Re: some ?'s about a odd TC setup

To: tesla-at-pupman-dot-com
Subject: Re: some ?'s about a odd TC setup
From: "Robert Jones" <alwynj48-at-earthlink-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Sun, 28 May 2000 13:12:24 -0600
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

Hi Kevin,

So have I got it right you don't connect the lower end of your coil to
anything not even to the secondary ground.

In which case a suggest you do connect to the ground or earth side of the
secondary. If your don't like the idea of that just mount the coil on a
large sheet of aluminum foil and connect that to the lower end of the coil.
But if you draw a spark to anything thats not connected to the foil, the
foil could end up at a high voltage. In general you never let anything float
including the primary.

Although the coil does not have to be grounded if its not your relaying on
its intrinsic C of the other end from which you draw sparks to close the
current loop. This is much higher impedance than a ground connection so it
reduces the output voltage. The when you try to draw sparks from the top end
you are in effect earthling it and the bottom end becomes the high voltage
end hence the flash over to the primary.

I think your right with out the ground connection it going to try to be a
bipolar coil so I guess you had difficulty tuning it.


Regards Bob

-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Sunday, May 28, 2000 3:27 AM
Subject: some ?'s about a odd TC setup


>Original Poster: "Kevin D" <teslacoilfreak1-at-mediaone-dot-net>
>
>
>
>  Hello Everyone,
>
> I have a few questions about my current "practice coil",mainly questions
>about my layout.
> My coil uses a 555 circuit to drive a ignition coil,the coil output is
>connected to a bank of 25 1N4007 rectifiers.The spark gap is two caridge
>bolts spaced at about .125"and the tank cap is a MMC type cap(1 strings of
>10 -at- .056uf/cap).The secondary resonator is 14" long 3" Dia. and wound with
>22Awg wire,there is no topload.The primary resonator is 5 turns of 9Awg
wire
>spaced a 3/8" appart in a helix config.
> Now here is the part that I have questions about.I had no where to put a
>ground so I had very poor arcs(1/4" and problems with the sec. arcing to
the
>pri.)So I tried connecting another resonator to the bottom of the sec.
>resonator(16" long/1.5" Dia. w/22Awg wire)This improved the arc output to
>about a inch.
>I then decided to place a coffee can on top of the second resonator and
this
>made the arcs about 1 1/2" long.
> My first question is: why does doing this increase the arc length,my
second
>question is could this be considered a"uneven vertical bipolar coil"(that
is
>realy out of tune)
>
>TIA,
>Kevin Dalpe
>
>
>