Patent ID: 8669763

Claim:
A multi-axis fluxgate magnetic sensor comprising: a first magnetic core of a ring shape; a first excitation coil wound on the first magnetic core; first and second detection coils wound on the first ring-shaped magnetic core in such a manner that respective input axes of the first and second detection coils are orthogonal to each other; first and second signal detection/feedback units that are configured to detect outputs of the first and second detection coils, respectively, and provide feedback currents corresponding to output signals therefrom to the first and second detection coils, respectively; a first excitation circuit that is configured to supply an excitation current to the first excitation coil; a second magnetic core; a compensation coil wound on the second magnetic core; and a compensation signal generation unit that is configured to generate a compensation current to be applied to the compensation coil by adding the outputs of the first and second detection coils; wherein the second magnetic core and the compensation coil are disposed so that a compensation magnetic field created by the compensation coil cancels interference between feedback magnetic fields produced by the feedback currents provided to the first and second detection coils wound on the first magnetic core.