Re: HV probe for primary measurements

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

Original poster: "robert heidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-desertgate-dot-com>

Greg: a healty respect is valid. From the net. 16 turns of insulated wire
wound on a ferrite core via a 50 ohm coax to a 3W 50ohm noninductive load to
a scope or volt meter with the ground/shield well grounded. I suggest a
single strand of RG8 core or other high voltage wire as the core wire to
your NST and spark gap. Just a single HV wire threaded through the hole of
the toroid. If you use a fold open or cut in half toroid you can make a
clamp-around current connection with a 16:1 ratio. I have made these with
two 1/2 toroids glued to  a clothes pin to hold the toroid pieces together
for use. A Dremmel-tool cut off wheel will cut ferrite if you can't find one
pre-cut or hinged.
  Robert  H

> From: "Tesla list" <tesla-at-pupman-dot-com>
> Date: Fri, 27 Sep 2002 12:20:14 -0600
> To: tesla-at-pupman-dot-com
> Subject: HV probe for primary measurements
> Resent-From: tesla-at-pupman-dot-com
> Resent-Date: Fri, 27 Sep 2002 12:39:52 -0600
> 
> Original poster: "Gregory Peters by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <s371034-at-student.uq.edu.au>
> 
> Hello TCML,
> 
> 
> I would like to use my CRO to examine the waveforms in my primary
> circuit during operation. Can someone point me in the direction of
> some suitable schematics for either a HV probe or some kind of
> current transformer metering device? I saw Terry's setup using the
> optocouplers, but I can't find any schematics or theory of operation.
> Can I just use a big string of resistors? The idea of directly
> measuring the primary voltages and currents, quite frankly, scares
> the utter crap out of me. But I am determined to investigate them. I
> will NOT be touching the CRO during operation as a result. I just
> don't want to go anywhere near it.
> 
> What about making a current transformer by winding some wire around a
> ferrite core?
> 
> Cheers,
> 
> 
> Greg.
> 
> 
>