Meas Deutschland Gmbh

Fritz Dettmann

Axel Bartos

Armin Meisenberg

A magneto-resistive sensor for measuring a magnetic field based on an anisotropic magneto-resistive (AMR) effect or a gigantic magneto-resistive (GMR) effect comprises a substrate and a plurality of resistors that include first magneto-resistive layer strips arranged in form of a bridge circuit on the substrate. The plurality of resistors have a resistance value that depends on a magnetic field strength. At least one second layer strip is connected in series with the first magneto-resistive layer strips of at least one of the plurality of resistors. The first magneto-resistive layer strips have a resistance that depends on temperature according to a first positive temperature coefficient; and the at least one second layer strip has a resistance that depends on temperature according to a second temperature coefficient different from the first temperature coefficient, the second temperature coefficient being non-negative.

Temperature compensating magneto-resistive sensor for measuring magnetic fields

Disclosed are absolute measuring systems comprising measuring rods that are composed of groups of at least two magnetic segments. The magnetic segments of at least one group have the same length in the direction of measurement while the magnetic segments of the different groups have different lengths. For arrangements encompassing more than two sensors on the single-track measuring rods, multistage phase difference processes are disclosed which result in high resolutions and accurate measurements while allowing for great measured lengths and, when anisotropic magnetoresistive sensors are used, for example, an unambiguous angle measurement range of 360&#xb0;. FIG.best represents the essence of the invention.

Arrangement and method for magnetic determination of a linear length or a rotary angle

Magnetoresistive sensors based on the AMR or GMR effect exhibit substantially enlarged linear characteristic curve regions as a result of the fact that their resistances are composed of magnetoresistive layer strips of differing anisotropic forms. Differing anisotropic forms can be achieved by different strip widths, strip thicknesses, strip intervals or strip materials. The temperature compensation for the output voltage of the magnetoresistive sensors, at least at one point on the characteristic curve, is achieved by the series connection of an additional layer strip with a temperature coefficient that differs from that of the magnetoresistive material to at least one magnetoresistive resistance of the sensor.

Magneto-resistive sensor for measuring a magnetic field based on an anisotropic magneto-resistive (AMR) effect or a gigantic magneto-resistive (GMR) effect

A magneto-resistive resistor for use in sensors for determining alignment of the sensor relative to a homogeneous magnetic field include an anisotropic magnetoresistive (AMR) strip having a longitudinal extent and a first and second edge along the longitudinal extent. The first and second edge have a shape along the longitudinal extent such that the direction of current flowing through the strip varies continuously along the longitudinal extent of the strip. The shape of the first and second edges produce a resistance determining angle with respect to the homogeneous magnetic field, the angle varying throughout the length of the strip and filtering out harmonics. A sensor bridge comprising at least one AMR resistor pair, each resistor electrically connected to the other resistor, a positive input contact and a negative input, and an output voltage tap electrically connected between the resistors in each resistor pair.

Magnetoresistive sensor for determining an angle or a position

Magnetoresistive sensors which use the AMR or the GMR effect and indicate the direction of the homogeneous magnetic field of a rotatable permanent magnet in the angle measurement or the position of the sensor with respect to a scale, which is magnetized periodically in an alternating direction, for the position measurement, and in which the angle or position value is obtained from the quotient of the output signals from two bridges or half bridges with the aid of arctan interpolation, allow small measurement errors if the output signals have small harmonic components and hysteresis areas. In arrangements according to the invention, this is achieved by the resistors being composed of strips and by continuously varying the resistance-determining angle along the strip longitudinal extent for each constant magnetic field acting on the strips. The resistance-determining angle is between the current and magnetization direction for AMR sensors and is between the magnetization directions of two layer components for GMR sensors.

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Braunfels-Philippstein, Germany

Fritz Dettmann