Re: toroid shaped coil capacitance (fwd)

From: 	Tesla List Owner[SMTP:listown-at-pupman-dot-com]
Sent: 	Friday, January 02, 1998 1:01 PM
To: 	tesla-at-stic-dot-net
Subject: 	Re: toroid shaped coil capacitance (fwd)

---------- Forwarded message ----------
Date: Fri, 2 Jan 1998 00:57:49 -0700
From: richard hull <rhull-at-richmond.infi-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: toroid shaped coil capacitance

>Greetings Distributed Capacitance Enthusiasts:
>At 01:51 AM 12/31/97 -0600, you wrote:>
>>From: 	Haldun Karaca[SMTP:karaca-at-izmir.eng.deu.edu.tr]
><I am trying to realize a very high bandwidth Rogowski Coil s . Now I am trying
>>to formulate and minimise toroid shaped Bobbin capacitance .
>>Could you help me namely reccommend me literature that s aim is to
>>formulate capacitance value of toroid inductances .

I have wound up a gang of torodial rogowski coils when I was doing the Water
arc explosion work.  I would just wind away on a piece of 3/8" tygon tubing
with # 30 Kynar insulated wire and shunt the whole winding with a .1 ohm
carbon resistor.  (this is the classsic old method)  The modern method is to
integrate the output of a much lighter coil.

Most of the work I was doing was with 300KHZ damped wave pulses.  so a
self-resonant 3 mhz rogowski just put some trash on the first rising or
falling edge in the storage scope waveforms.

I hade to calibrate on the fly with a known current setup in the circuit for
which I was expecting to measure.  They worked great.  Wideband, but non-linear.

I got tired of doing this for every new iteration of circuit so parted with
$900.00 and got a Pearson.  They be folks with the plan and wideband.  The
thing is dead linear from .02Hz to 2.5mhz and just as passive a component as
a lead pipe.  How dey do dat!?  (Answer- years in the biz and they won't
even discuss the methodolgy with you!!!!!)

Richard Hull, TCBOR