Thin film magnetometer using magnetic vector rotation

Claim 1

A magnetometer for giving an output representative of the component of a magnetic field in a predetermined direction, comprising, in combination: a thin film of anisotropic material, containing first and second mutually perpendicular axes for alignment respectively parallel and normal to the predetermined direction of said component, said second axis coincIding with the preferred direction of magnetization of said film; a first winding encompassing said material and having its axis aligned with the preferred direction of magnetization of said material; driving means electrically energizing said first winding with uniform pulses of electrical current to produce an intermittent magnetic field in said material which combines with said component to cause angular oscillation of the magnetic vector of said material, the amplitude of said pulses being such that the magnitude of the combined field is always insufficient to cause reversal of the direction of magnetization of said material; a second winding encompassing said material, and positioned to be insensitive to pulses of current in said first winding, so that said angular oscillation of said magnetic vector induces pulses of current in said second winding; and output means connected to said second winding for actuation in accordance with the amplitude of said pulses of current, so that when said magnetometer is positioned in a magnetic field to be measured, the output means is activated in accordance with said component of the field.