Method and device for operating a position sensor
First Claim
1. A method for operating a position sensor having a first part and a second part, one of the first part and the second part being movable in relation to the other one of the first part and the second part, the first part having a first section magnetized in a first direction and a second section magnetized in a second direction that is different from the first direction, and the second part having at least one magnetic field sensor, the method comprising the steps of:
- detecting a magnetic field of the first part with the at least one magnetic field sensor;
converting the detected magnetic field into a signal having two levels depending on a polarity of a component of the magnetic field in a predefined spatial direction;
analyzing the signal to determine a relative position of the first part in relation to the second part;
detecting and storing a first level of the signal prior to a disabling of the at least one magnetic field sensor when the first part is at a standstill in relation to the second part;
subsequently detecting a second level of the signal and comparing the detected second level with the stored first level when the at least one magnetic field sensor is enabled; and
recognizing a valid level change if the detected second level is different from the stored first level.
1 Assignment
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Accused Products
Abstract
A method and a device for operating a position sensor made of at least two parts that move in relation to one another. The first part of the position sensor has at least two sections magnetized in different directions, and the second part has at least one magnetic field sensor which detects the magnetic field of the first part and converts it into signals having two levels depending on the polarity of the component of the magnetic field in a predefined spatial direction. The levels are supplied to a signal-processing arrangement which evaluates them to determine the relative position of the first part in relation to the second part. Prior to disabling the at least one magnetic field sensor when the first part is at a standstill with respect to the second part, the level delivered by the magnetic field sensor is stored, detected again after the magnetic sensor is enabled again, compared with the stored level, and if the measured level does not coincide with the stored level, the level change is evaluated as a valid level change.
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Citations
22 Claims
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1. A method for operating a position sensor having a first part and a second part, one of the first part and the second part being movable in relation to the other one of the first part and the second part, the first part having a first section magnetized in a first direction and a second section magnetized in a second direction that is different from the first direction, and the second part having at least one magnetic field sensor, the method comprising the steps of:
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detecting a magnetic field of the first part with the at least one magnetic field sensor; converting the detected magnetic field into a signal having two levels depending on a polarity of a component of the magnetic field in a predefined spatial direction; analyzing the signal to determine a relative position of the first part in relation to the second part; detecting and storing a first level of the signal prior to a disabling of the at least one magnetic field sensor when the first part is at a standstill in relation to the second part; subsequently detecting a second level of the signal and comparing the detected second level with the stored first level when the at least one magnetic field sensor is enabled; and recognizing a valid level change if the detected second level is different from the stored first level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A device for operating a position sensor having a first part and a second part, one of the first part and the second part movable in relation to the other one of the first part and the second part, the first part having a first section magnetized in a first direction and a second section magnetized in a second direction that is different from the first direction, comprising:
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at least one magnetic field sensor detecting a first magnetic field of the first part at a first predetermined time and converting the first detected magnetic field into a first signal as a function of a polarity of a first magnetic field component of the first magnetic field in a spatial direction, the first signal having one of a first level and a second level, the at least one magnetic field sensor detecting a second magnetic field of the first part at a second predetermined time and converting the second detected magnetic field into a second signal as a function of a polarity of a second magnetic field component in the spatial direction, the second signal having one of the first level and the second level; and a signal processing arrangement analyzing the first signal to determine a relative position of the first part in relation to the second part, storing a first determined level of the first signal, and detecting whether there is a level change between the first determined level of the first signal and a second determined level of the second signal, wherein the first magnetic field is detected prior to a disabling of the at least one magnetic field sensor when the first part is at a standstill in relation to the second part, wherein the second magnetic field is detected when the at least one magnetic sensor is enabled again, and wherein the level change is determined to be valid if the first determined level of the first signal is different from the second determined level of the second signal. - View Dependent Claims (22)
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Specification