Combined magnetic field gradient and magnetic field strength sensor
First Claim
1. A magnetic field sensor device comprising an oscillatory member and a current controller, wherein the current controller is arranged to pass an alternating current (AC) along at least first and second current paths provided through the oscillatory member, characterised in that the current controller is arranged to provide magnetic gradiometer mode operation in which current flow through the first current path is in substantially the opposite direction to current flow through the second current path.
1 Assignment
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Accused Products
Abstract
A magnetic field sensor device (2) is described that comprises an oscillatory member (8) and current control means (6). The current control means (6) is arranged to pass an alternating current (AC) along at least first (10) and second (12) current paths provided through the oscillatory member (8) and is arranged to provide magnetic gradiometer mode operation (i.e. to measure magnetic field gradient) in which current flow through the first current path (10) is in substantially the opposite direction to current flow through the second current path (12). The current control means (6) can also prove magnetometer mode operation (i.e. to measure magnetic field strength). The magnetic field sensor (2) may be used in a compass.
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Citations
43 Claims
- 1. A magnetic field sensor device comprising an oscillatory member and a current controller, wherein the current controller is arranged to pass an alternating current (AC) along at least first and second current paths provided through the oscillatory member, characterised in that the current controller is arranged to provide magnetic gradiometer mode operation in which current flow through the first current path is in substantially the opposite direction to current flow through the second current path.
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30. (canceled)
- 40. A compass comprising a device for measuring magnetic field strength characterised in that the compass additionally comprises a device for measuring magnetic field gradient.
- 42. A method of operating a magnetic field sensor device comprising the steps of taking a magnetic field sensor device comprising an oscillatory member and passing an alternating current (AC) through the oscillatory member, characterised in that the oscillatory member comprises at least first and second current paths and in that, during use, an AC is passed along the at least first and second current paths.
Specification