Patent ID: 9588149
Date: 2017-03-07
CPC Classifications: G01R

Claim:
1. A current measurement circuit comprising: an integrator circuit having a first input, and an output; a first transformer including a first winding about a magnetic core, the magnetic core including an opening through which a conductor carrying measurement current passes, the first winding having a first terminal and a second terminal, the first winding configured to generate a first current based on a first flux in the magnetic core; a second transformer including second and third windings, each of the second and third windings having a first terminal and a second terminal, the first terminal of the second winding coupled to receive the first current from the first terminal of the first winding, the second terminal of the second winding coupled to the second terminal of the third winding, the first terminal of the third winding coupled to the first input of the integrator circuit; and a current measurement unit operably coupled to measure the current through the second winding of the second transformer; wherein the output of the integrator circuit is operably coupled to provide an error current to the second transformer.