Scoped? primary

To: "'Tesla List'" <tesla-at-pupman-dot-com>
Subject: Scoped? primary
From: Tesla List <tesla-at-stic-dot-net>
Date: Mon, 17 Aug 1998 08:49:43 -0500
Approved: tesla-at-stic-dot-net

----------
From:  terryf-at-verinet-dot-com [SMTP:terryf-at-verinet-dot-com]
Sent:  Sunday, August 16, 1998 5:43 PM
To:  tesla-at-pupman-dot-com
Subject:  Re: Scoped? primary

Hi Chris,


At 10:02 PM 8/16/98 +0100, you wrote:
>Hi all,
>
>I found that you can connect you scope to the primary of your coil without
>blowing the thing up.
>
>What I did was to se my coil up using the 8th turn of my primary, as I have
>14 turns on this one, I took the free end and connected about 5meg onto it
>and then went to my probe.  I didn't connect the ground I left it floating.
>I tried to move it and I got xapped so I ain't a good idea anyway.

The free end is probably at twice the potential of the primary circuit due
to transformer action with the tap you mention.  Be absolutely sure the 5
meg resistor will withstand that voltage.  The ground lead should be
grounded by the scope's ground.  You probably graounded yourself when you
touched it and drained you body's charge (you were in the E field of the
coil).  I assume you have a 10:1 probe or something like that.  Beware that
you may damage the probe.

>
>I sawthe RMS power at about 10Kv at the resonat frequency.  I forgot to
>write down the frequency, Huh.  I also saw the huge surge of the coil which
>appeard right on top of the RMS wave.  Rather odd seeing 2 waves as 1.

The RMS was from the primary transformer charging.  The surge was due to gap
firing and all the "stuff" from the coil.

>
>The first surge was off the screen, and about half way down that cycle it
>cam back on my screen and then got smaller and smaller until it flat lined.
>
>This is a clear indication of the cap loosing X% each cycle of the resonant
>frequency.  As there are losses each cycle, this clearly shows up and It was
>really clear as well to see what was going on.
>
>Just thought I'd mention it.
>
>
>
>All the beST,
>Chris.
>
>chris.swinson-at-zetnet.co.uk
>www.users.globalnet.co.uk/~mega01/    <--- moved site to...
>www.users.zetnet.co.uk/mega.disczine/
>
>
>

You may want the check out my field probes at:

http://www.peakpeak-dot-com/~terryf/tesla/experiments/experiments.html

They give great information about your coil and are far safer for your
equipment.  

        Terry Fritz