Patent ID: 9212934
Filing Date: 2015-12-15
Classification: G01B,G01D

Abstract:
1. A linear position detector, comprising: at least a first magnetic-field sensor and a second magnetic-field sensor, each generating respective sensor signals; a signal-processing unit configured to determine, during an initialization mode of operation, a minimum signal and a maximum signal for each of the first and second magnetic-field sensors over a full scale range of the linear position detector as a function of a magnetic-field source movable linearly between end positions of a movement axis relative to the linear position detector; a selection means for selecting one of the first or second magnetic-field sensors based on the one having a greater degree of linearity of its magnetic-field characteristic curve in the range of movement; and wherein the signal-processing unit has a signal input and an offset output, the offset output providing an offset signal, the first and second magnetic-field sensors are connected respectively to a first or second switching device that is set up to generate a first phase signal and second phase signal from the respective sensor signals of the first or second magnetic-field sensor, the first and second phase signals are associated with a change in a direction of a Hall current through the first or second magnetic-field sensor, an adjustment circuit that is set up to generate a correction signal as a function of the minimum and maximum signals or first and second phase signals of the selected first or second magnetic-field sensor, the correction signal is inverted synchronously with the first and second phase signals of the selected first or second magnetic-field sensor, the signal-processing unit is configured to derive the offset signal from the respective sensor signals or first and second phase signals of the selected first or second magnetic-field sensor, a first combination means that effectively couples, on an input side, the selected first or second magnetic-field sensor to the offset output and connects, on an output side, to the signal input, and a second combination means that is connected to the offset output and the adjustment circuit on an input side of the second combination means, and is coupled on an output side to the first combination means such that the correction signal and the offset signal are superimposed on the sensor signals or first and second phase signals of the selected first or second magnetic-field sensor.