Rogowski coils

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

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi All,

	It would appear that Rogowski coils may be a fairly promising way to
measure primary currents in Tesla coils.  It is not straight forward and
would need some R&D work but the advantage of super high current ability is
really neat.  One of the best papers on this is at:

http://www.pemuk-dot-com/pdf_files/816epe99.pdf

Many of the commercial designs (that are published) seem to be rather
limited by the simple op-amp integrators.  "I" would think one would not
worry with the integrator but rather pick up the di/dt waveform with a
digital scope into a data file and let Excel do the integration.  That
would do away with a lot of the mess involved.

The high voltage could fairly easily be shielded by putting the coil in a
metal (non-ferrous) box with a split in it to avoid the shorted turn effect
(although the split may have to withstand 10's of kV...).

I always worry about current transformer type circuits since if the burden
resistor fails, it forms sort of a little tesla coil with the output being
the scope's input electronics =:O

I will put this info away for a day when the need comes up.  Thanks to all
who helped me spell it and all ;-) 

I'll look into Hall sensors next...

A great overview page of current sensors is at:
http://www.pcim-dot-com/articles/1998/art0001/art1.html

Cheers,

	Terry     Happy New Year!!