Short-Circuited Fluxgate Output Current

摘要

The alternative coupling of short-circuiting a fluxgate sensor secondary coil by connecting it to the inverting input of a current amplifier is shown to have significant advantages over the more conventional unloaded or second harmonic tuned voltage coupling. The short-circuit output current impulses are independent of changes in the excitation level, and sensor performance is not degraded by cable and coil stray capacitances or by resistive loads from the feedback circuit. The current impulse amplitude is proportional to the average-to-minimum secondary selfinduction ratio minus 1, and to a virtual current in the secondary coil corresponding to the external magnetic field.