Coil-less fluxgate operated in feedback mode by means of dc current

In this paper we present a novel method to operate a coil-less fluxgate in feedback mode without the need of any coil to generate the compensating field. The sensor is kept in the initial working point of its characteristic by adding a dc current to the excitation current. A physical explanation of the working mechanism - which makes the feedback possible by adding of compensating current - is given; it is based on the two-domain model of coil-less flugate operation. Then, we show the experimental results, focusing on the improvement of the linearity of the characteristic. Finally the limits and drawbacks of the method are presented.