RE: Differential voltage probes

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

Hi Richard,

Such a probe would be for measuring things like gate drive or capacitor 
voltages...  Since the input impedance is fairly low, "fragile" signals 
would get loaded down.  Finn just does not want to float the whole scope 
(anymore ;-)), buy a $1000 probe, or mess with the two probe A - B channel 
thing (gets odd on digital scopes anyway).  SS coils have a lot of say 600 
volt things that float in reference to ground.  This probe could go across 
a 600 volt cap with the voltage at say 300 and 900 volts above 
ground.  That is actually pretty messy to do, but a differential probe 
makes such things easy and the signals stay cleaner if ground is not involved.

In our case, we don't need any super performance at all.  Thus we can save 
about $1000 off the price of say a Tek P5205 probe ;-))

http://www.testequity-dot-com/products/573/

I do have a P5205 but they are really expensive!!  However, I can use mine 
to test this simple version out and then we all could have a very useful 
probe for such work.

Cheers,

         Terry

At 10:15 PM 6/27/2003 -0400, you wrote:

>Hi Terry, list,
>
>This is great fun.  As you'll remember I'm a great advocate of measuring
>differential signals in TCs.  Always referencing everything to earth ground
>often gives a distorted picture of what's really going on in TCs.
>
>A couple of questions:  What do you intend to measure with your
>differential probes?  Small voltage differences on a SS circuit board or
>separated "antennae" signals from around the TC?  Makes a big difference in
>design.  Especially the front ends.
>
>RWW
>
> > Hi All,
> >
> > Finn and I have been thinking about differential voltage probes that
>would
> > be useful for solid state Tesla coil work.  Rather than spend $$$$ on
> > commercial ones, say from Tek, we were wondering about just making our
>own.
>
>