Multi-core orthogonal fluxgate sensor

Abstract

A multi-core orthogonal fluxgate sensor is presented, in which the sensing element is formed by multiple insulated thin-wires of a soft ferromagnetic material. Experiments were conducted to investigate the characteristics of the sensor. The results showed that the sensor sensitivity increased exponentially with increasing the number of cores in the sensing element. Such an increase was neither due to increase in the excitation current passing through the sensing element because the number of cores was increased, nor due to the increase of the ferromagnetic material in the sensing element. The results further showed that the sensitivity increases with increasing the number of cores exponentially only if the multiple cores of the sensing element are closely packed, and that there is a resonance in the sensing output corresponding to an external field, which becomes significant as the number of cores reaches a certain large value and varies in its corresponding external magnetic field with the frequency of the excitation current. All the results indicated that in multi-core orthogonal fluxgate sensor, driven by the high frequency of the excitation current passing through the multiple cores, there is a dynamic magnetic interaction between the cores in the sensing element, which increases the sensitivity. © 2005 Elsevier B.V. All rights reserved.