Magnetometer
A magnetometer with only a SET operation for initiating a magnetic orientation within a magnetic field sensor based on anisotropic magnetoresistive (AMR) technology. Within the magnetometer, the relative orientations of the respective X, Y and Z axes detectors are maintained by a package in which all detectors are mounted on a single assembly with the Z axis sensor displaced and held orthogonal to the other two sensors by potting material. Shorting bars on respective barber pole structures are provided with a geometry that allows for closer placement of adjacent barber poles to one another. The barber pole structures are deposited in a nested orientation which provides for balanced resistance legs in a Wheatstone bridge construction.
1. A method of operating an electronic magnetic field measuring device comprising a plurality of anisotropic magnetoresistive (AMR) sensors, the method comprising:
realigning a respective magnetic domain orientation of each AMR sensor in only one direction;
subsequent to the realigning of the respective magnetic domain orientation of each AMR sensor, detecting an output signal from the plurality of AMR sensors, the output signal being representative of a local magnetic field; and
implementing a next realignment step a predetermined amount of time after the prior realignment step.
2. A method of operating an electronic magnetic field measuring device comprising a plurality of anisotropic magnetoresistive (AMR) sensors, the method comprising:
realigning a respective magnetic domain orientation of each AMR sensor in only one direction;
subsequent to the realigning of the respective magnetic domain orientation of each AMR sensor, detecting an output signal from the plurality of AMR sensors, the output signal being representative of a local magnetic field;
detecting a maximum value Vmax for the output signal since last realigning the magnetic domain orientations;
detecting a minimum value Vmin for the output signal since last realigning the magnetic domain orientations; and
comparing (Vmax+Vmin)/2 to a predetermined value PV to determine whether or not the realigning step should be repeated.
3. The method of claim 2 , wherein comparing further comprises:
implementing a next realignment step if (Vmax+Vmin)/2 is greater than the predetermined value PV.
4. The method of claim 1 , wherein the realigning step comprises:
passing a first current in a first direction through a first conductor positioned near the plurality of AMR sensors,
wherein a first magnitude and a first duration of the first current are chosen to sufficiently realign the magnetic domain orientation of each AMR sensor.
5. The method of claim 4 , further comprising:
orienting the first direction of the first current to pass each AMR sensor substantially perpendicular relative to a longitudinal direction of each respective AMR sensor.
6. The method of claim 2 , wherein the realigning step comprises:
passing a first current in a first direction through a first conductor positioned near the plurality of AMR sensors,
wherein a first magnitude and a first duration of the first current are chosen to sufficiently realign the magnetic domain orientation of each AMR sensor.
7. The method of claim 6 , further comprising:
orienting the first direction of the first current to pass each AMR sensor substantially perpendicular relative to a longitudinal direction of each respective AMR sensor.