Position detection apparatus with distributed bridge sensor
AssigneeHoneywell International Inc.
InventorsJay R. Goetz, Edgar R. Mallison
Life of this patent
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Abstract
A position determining apparatus including a magnet that is attached to a movable member which moves along a defined path of finite length. An array of distributed bridge sensors are located adjacent to the predefined path. The distributed bridge sensors each have one or more magneto-resistive elements positioned at a first location along the defined path of the magnet, and one or more other magneto-resistive elements positioned at a second location along the defined path. The magneto-resistive elements at the first location experience a different magnetic field component than those at the second location. The distributed bridge sensors produce an increased linear range relative to non-distributed bridge sensors of the prior art.
Claims45
A distributed bridge for detecting the position of a magnet that is movable along a defined path, the magnet having a first polarity pole and a second polarity pole with no intermediate poles therebetween, the magnet producing a magnetic field, comprising:
- two or more magneto-resistive elements connected in a bridge configuration, one of the magneto-resistive elements is positioned at a first location along the defined path and sense the magnetic field of the magnet at the first location, and another one of the magneto-resistive elements is positioned at a second location along the defined path and sense the magnetic field of the magnet at the second location, wherein the first location is spaced from the second location.
Apparatus for determining the position of a magnet that is movable along a defined path, the magnet having a first polarity pole and a second polarity pole with no intermediate poles therebetween, the magnet producing a magnetic field, comprising:
- first magnetic sensor means positioned at a first location along the defined path for sensing the magnetic field of the magnet at the first location;
- second magnetic sensor means positioned at a second location along the defined path for sensing the magnetic field of the magnet at the second location, wherein the second location is spaced from the first location;
- the first magnetic sensor means including a first magneto-resistive element and a second magneto-resistive element;
- the second magnetic sensor means including a third magneto-resistive element and a fourth magneto-resistive element;
- the first magneto-resistive element of the first magnetic sensor means is coupled to the fourth magneto-resistive element of the second magnetic sensor means in a half-bridge configuration for providing a first output signal;
- and
- the third magneto-resistive element of the second magnetic sensor means is coupled to the second magneto-resistive element of the first magnetic sensor means in a half-bridge configuration for providing a second output signal.
Apparatus for determining the position of a magnet that is movable along a defined path, comprising:
- first magnetic sensor means positioned at a first location along the defined path;
- second magnetic sensor means positioned at a second location along the defined path, wherein the second location is spaced from the first location;
- the first magnetic sensor means including a first magneto-resistive element, a second magneto-resistive element, a third magneto-resistive element and a fourth magneto-resistive element, the first magneto-resistive element, the second magneto-resistive element, the third magneto-resistive element and the fourth magneto-resistive element coupled together in a full bridge configuration for providing a first output signal and a second output signal;
- the second magnetic sensor means including a fifth magneto-resistive element, a sixth magneto-resistive element, a seventh magneto-resistive element and an eighth magneto-resistive element, the fifth magneto-resistive element, the sixth magneto-resistive element, the seventh magneto-resistive element and the eighth magneto-resistive element coupled together in a full bridge configuration for providing a third output signal and a fourth output signal;
- the first output signal is coupled to the fourth output signal for providing a first sensor output signal, and the second output signal is coupled to the third output signal for providing a second sensor output signal;
- and
- differencing means for providing a magnet position signal, the magnet position signal derived from the difference between the first sensor output signal and the second sensor output signal.
A method for determining the position of a magnet that is movable along a defined path, the magnet having a first polarity pole and a second polarity pole with no intermediate poles therebetween, the magnet producing a magnetic field, the method comprising the steps of:
- sensing the magnetic field of the magnet using a distributed bridge sensor, wherein the distributed bridge sensor senses the magnetic field from at least two locations along the defined path;
- and
- providing an output signal that is related to the position of the magnet.
A method for determining the position of a magnet that is movable along a defined path, the method comprising the steps of:
- sensing the position of the magnet using a distributed bridge sensor;
- sensing the position of the magnet using a first non-distributed bridge sensor, the first non-distributed bridge sensor located at a first location along the defined path;
- and
- sensing the position of the magnet using a second non-distributed bridge sensor, the second non-distributed bridge sensor located at a second location along the defined path, wherein the first location is spaced from the second location.
Dependencies are inferred from the claim text.