Excitation tuning in fluxgate sensors

The performance of fluxgate sensors is intrinsically dependent on the excitation parameters. When the peak amplitude of the excitation current is high, perming is greatly reduced. High excitation frequency increases the sensor bandwidth. The power consumption can be lowered and the offset stability increased by judicious tuning of the circuit. This paper describes a simplified analytical solution for the non-linear excitation circuit which is very different to the solution for a free-running tank circuit. The new model is straightforward to use and greatly simplifies the design of the fluxgate excitation tank. Experimental results are presented to validate the models.