Giant Magnetoimpedance Current Sensor With Array-Structure Double Probes

Abstract

We have designed a novel giant magnetoimpedance (GMI) noncontact current sensor with array structure double probes. Unlike previously reported sensors, our sensor's probes consist of many pieces of commercial amorphous ribbons, which are parallel to each other, equidistant, and connected in series, and a permanent magnet provides a bias magnetic field. The double-probe output shows the best sensitivity and linearity at a bias magnetic field of 7.40 Oe. Under this field, the sensor shows sensitivity of 1 V/A in the current range of plusmn3 A, measurement precision of less than 0.15% at room temperature, and good thermal stability in the temperature region between -20degC and 30degC.