Double Coil-Less Fluxgate in Bridge Configuration

Abstract

In this paper, a new method for excitation of coil-less fluxgate is presented. The purpose of this method is to reduce the spurious component of the output voltage, allowing us to increase the amplification. The method is based on the employment of two coil-less fluxgates in a double bridge, which injects pulsing current in opposite direction in each wire. By taking the difference of the voltages on the two wires, we suppress the component of the voltages, which does not change under application of external measured field. The sensitive axes are in opposite direction, so the wire feels opposite field. As a result, we will obtain an output voltage with low peak value, including only the component of the voltage that changes when we apply external field. Finally, we propose an improved version of the double bridge to allow the employment of two sensing elements with difference characteristics. This is obtained by optimizing the suppression of the spurious voltages and, at the same time, setting independently chosen values of exciting current for each wire.

Contactless magnetic nanoparticle detection platform based on non-linear GMI effect

“…Although this working principle is similar to (coil-less) fluxgate sensors [36], some differences can be stated between them. Coil-less fluxgate sensors usually work under lower frequency than those based on the GMI effect [37], giving, as a result, a negligible role of the resistance in the fluxgate sensor output [38] in contrast with the relevance exhibited in the GMI sensors. Anyway, we previously analyzed the detection capacity for the superparamagnetic MNPs detection ( ) [39], 𝑉 2𝑓 𝐹𝑒 3 𝑂 4 [40] where the larger detection capacity of was demonstrated.…”

Orthogonal Fluxgates

“…As previously explained, these peaks will be shifted by the external field to opposite directions, but they will continue to be present in the output. A technique proposed by (Butta et al, 2010a) is presented to remove the inductive peaks and obtain an output voltage that is null for no applied field and whose amplitude increases proportionally to it. The method is based on a double bridge with two sensing elements fed by current in opposite directions.…”

Design and Realization of a Novel Compact Fluxgate Current Sensor

“…Sharafi [7] presented a new sensor with low-power consumption. Butta and Ripka [8] proposed a method for the sensor design to reduce the spurious component of the output voltage. Velasco-Quesada [9] designed a fluxgate current sensor with three cores for high current measurement, and achieved improvement in consumption.…”