A low-cost multiple Hall probe current transducer

An inexpensive but highly stable and accurate transducer has been developed for the measurement of large currents associated with the operation of the DIII-D tokamak at General Atomics. The inherent problems with integrator circuits required by Rogowski loops and the excessive cost of ‘‘secondary compensation current’’ devices have led to this development. The transducer requires several inexpensive Hall effect devices and a simple, stable, and linear interface circuit. Analysis of the initial performance characteristics is very encouraging and has led to several useful applications of the transducer to date, with plans for the installation of additional devices in the future. The low cost and reasonable accuracy of the transducer make it an attractive alternative to commercially available devices.