HIGH ACCURACY DIFFERENTIAL CURRENT SENSOR FOR APPLICATIONS LIKE GROUND FAULT INTERRUPTERS

摘要

A sensor with multiple magnetic field sensing elements for use in current sensing and other applications is presented. In one configuration, the sensor obtains differential and absolute current measurements of current in current-carrying conductors. When employed in a ground fault interrupter application, a first magnetic field sensing element is used to measure the absolute current flowing in the phase conductor (phase current), a second magnetic field sensing element is used to measure the absolute current flowing in the neutral conductor (neutral current) and a difference between the phase and neutral currents is measured by a third magnetic field sensing element or determined from measurements of the first and second magnetic field sensing elements. In another configuration, a measure of the difference between currents and/or the sum of currents in current-carrying conductors can be obtained. An arrangement of multiple sensing elements may be used for misalignment detection/correction.