Re: What efficiency?!

To: tesla-at-pupman-dot-com
Subject: Re: What efficiency?!
From: Bert Hickman <bert.hickman-at-aquila-dot-com>
Date: Thu, 14 Nov 1996 07:00:48 -0800
Tesla List wrote:
> 
<SNIP>
> > > > Subject: Re: What efficiency?!
> 
> >From huffman-at-fnal.govWed Nov 13 23:28:55 1996
> Date: Wed, 13 Nov 1996 09:03:34 -0600
> From: huffman <huffman-at-fnal.gov>
> To: tesla-at-pupman-dot-com
> Subject: Re: What efficiency?!
> 
>     [The following text is in the "ISO-8859-1" character set]
>     [Your display is set for the "US-ASCII" character set]
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> 
> Bert,
> I've used Pearson CT's here at work in the past. Some units are very wide
> band. One of the tricks they use is in the core material. Two different
> core materials within the same package is needed to get the BW. They are
> also well shielded against electric fields. You have to pay for all their
> dinking around.
> Dave
> 
> ----------
<SNIP>
> > > Big snip
> >
> >
> > > > I got tired of recal.ing the coils, and purchased a wide band Pearson
> > > > current monitor recently for $900.00 out of pocket. (ouch)  Good
> > > > instruments improve results and reduce hassles.   This is a good one
> and
> > > > can handle 200,000 amps with a bandwidth of from .5 hz to 4Mhz.  It's
> the
> > > > cat's pajamas!
> > > >
> > > > Richard Hull, TCBOR
> > >
> > > Richard,
> > >
> > > Thanks for a very practical and useful post!! Just what is it that the
> > > Pearson has that one of your Rogowski coils doesn't - what do they do
> > > differently that justifies $900?
> > >
> > > -- Bert --
> >
> > Bert,
> >
> > The object is to make the coil relatively high inductance,, but remain
> > resonant at very high frequencies and achieve a resonant Q of
> > .00000000000000001. (ultrawide bandwidth-zero resonant rise).  They have
> > a process that is potted in tar and sealed in a solid metal framework.
> >
> >
> >   I'm not tearin' in ta' mine fella'!  Not at $900.00!  One might only
> > guess.  They gotta' shoot for maximized losses, zero rise, and infinite
> > bandwidth in a total passive device.  That's why they get the big bucks!
> >
> > Richard Hull,  TCBOR

Dave,

How'd you find out... Did you tear into one of yours??  <:?)

Seems to me that if you use NO core, you'd get even better bandwidth
(ala a Rogowski coil...) 

-- Bert --