Re: john06.jpg

To: tesla-at-pupman-dot-com
Subject: Re: john06.jpg
From: Terry Fritz <terryf-at-verinet-dot-com>
Date: Tue, 22 Sep 1998 12:50:48 -0600
Approved: terryf-at-verinet-dot-com
In-Reply-To: <9809221647.AA23814-at-us8rmc.bb.dec-dot-com>

Hi Gary,

At 12:47 PM 9/22/98 EDT, you wrote:
>From : Gary Lau  22-Sep-1998 1223 <lau-at-hdecad.ENET.dec-dot-com>
>
>Hi Terry:
>
>I'm looking at the scope traces you posted at:
>www.peakpeak-dot-com/~terryf/tesla/misc/, in particular john02 and john06.jpg.
>
>Perhaps my confusion is partly due to not being clear on what the top
>trace is.  In john02, I'm guessing it's primary current, while john06 is
>primary capacitor voltage?

The top trace in john02.jpg is the voltage across the primary inductor at
10kV/div.  The top trace in john06.jpg is across the primary capacitor also
at 10kV/div.  I didn't make it clear that I had change the probe to the
primary cap in this picture.


>
>Anyway, the unusual thing is that in both photos, the primary seems to be
>ringing at Fres, AFTER QUENCH.  I would have expected the primary to be
>dead-quiet after quench.  Is this real, or is this just some measurement
>crosstalk?

The primary voltage you see after quench is due to the secondary energy
creating a voltage back on the now open primary by transformer action.  

	There is some load from the input filters in my coil which is about 10k
ohms resistive in series with a 2.7nF cap.  The effects of this load are
not straight forward.  This load probably helps to reduce the voltage on
the open gap which aid the quenching.  There is a lot more to this subject :-)

>
>Regards, Gary Lau
>Waltham, MA USA
>
>