If the immensely useful "almost indistinguishable from magic" cheap
flexible (in several ways) "Rogowski Coil" is "just a name" or a mystery
then read this.

A 25 slide PDF slideshow by Analog Devices that gently introduces this
immensely useful device with a few less usually made  practical pointers
added (eg far field net flux cancellation)

Rogowski coil current sensing - better than usual introduction - Here used
for current sensing for energy metering but of immense value overall


http://www.analog.com/static/imported-files/recommended_reading/688920132Cu=
rrent_sensing_for_meteringNew.pdf

Note the absolute necessity to use an integrator when using a Rogowski coil
to measure current.
In some cases this can be as simple as a passive RC circuit.

AD use a digital integrator in this application and show why.

Achieved errors including integrator of better than -0.1% - + 0.05% over
65A measuring range at 25 C power factor =3D1



       Russell McMahon
--=20
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