An Alternating Current Amplitude Sensor Utilizing Saturating Magnetic Cores

Toroidal magnetic cores are used for noncontacting alternating current-sensing in applications such as circuit breakers and ground fault interrupters. In such applications, it is often desirable to maximize the voltage induced in the sense coil on the core. In order to maximize this voltage with respect to the sensed current, core design parameters are developed for 60- and 400-Hz applications. The effects of core material, core size, temperature, frequency, and winding are analytically determined and experimentally verified.