Design, Modeling, and Verification of High-Performance AC–DC Current Shunts From Inexpensive Components

A new type of ac current shunt for ac–dc current transfer is presented for which the ac–dc current differences at frequencies from 10 to 100 kHz are calculated with uncertainties smaller than $\pm 9\ \mu\hbox{A/A}$ in the current range of 30 mA–10 A. This is an independent realization of the ac–dc current-transfer standards in addition to the step-up method used at most National Metrology Institutes. The construction, modeling, and experimental verification of the shunts are described.