TSSP: List Archives

From: "Terrell W. Fritz"
Date: Sat, 14 Sep 2002 17:21:13 -0600
Subject: Re: [TSSP] Top Voltage

Hi Paul,

At 09:09 PM 9/14/2002 +0100, you wrote:
.......
>
>so the actual breakout appears some 50% to 70% higher than predicted.
>We'll have to look more closely at this.

Yes!!  Breakout seems to be very finicky.   Sometimes it is consistent, and
other times it just does not want to breakout.  I suspect dust or some variable
is greatly affecting the breakout point.

..............
>Consider the sinusoidal component of the fibre probe trace
>(yellow) which shows the current charging the fixed cap of
>rod+sphere.  The polarity of this suggests that you have
>the probe signal inverted somewhere.  Probe current should
>lead the voltage waveform, not lag.  For example, consider
>the probe trace just before the breakout spike.  Voltage is
>on a rising positive slope, so current will be flowing *into*
>the rod+sphere cap.  Your probe signal shows this as negative
>current, ie you are reporting current flowing *into* the topload,
>not out of it.
>
>Sure looks like your breakout is occuring on +ve half cycles and
>that the fibre probe is inverted somehow.

I looked at the currents and there are a lot of places for things to get
backwards :-))  I was going to figure it all, out but the top probe noise thing
took over...

>
>> The breakout point was very consistent and easy to adjust.
>
>Fantastic.  A stable test setup is the best thing we can hope for,
>the rest is up to us!

That was yesterday........ Far more finicky today...  All the electronics seems
fine but it just breaks out "different".   It was rainy yesterday, maybe higher
humidity tends to stabilize it... 

So, I need to pin things back down more.  The little elves of confusion seems
to have crept in all over the place :o)

Cheers,

        Terry


Maintainer Paul Nicholson, paul@abelian.demon.co.uk.