Sensitec Gmbh

Zf Friedrichshafen Ag

Lust Antriebstechnik Gmbh

Carl Zeiss Industrielle Messtechnik Gmbh

Brose Fahrzeugteile Gmbh & Co Kg, Coburg

Imo Institut Fur Mikrostrukturtechnologie Und Optoelektronik E.v.

Institut Fur Mikrostrukturtechnologie Und Optoelektronik E.v.

Institut Fuer Mikrostrukturtechnologie Und Optoelektronik E.v.

Lust Electronic-systeme Gmbh

Universitat Bielefeld

Igedi Gbr

Microcoat Biotechnologie Gmbh

Bit Analytical Instruments Gmbh

Ernst Reiner Gmbh & Co. Kg

I-sys Mikro- Und Feinwerktechnik Gmbh

Uwe Loreit

Jochen Schmitt

Thomas Engel

Joachim Spratte

Martin Budaker

Ulrich Gengenbach

Fritz Dettmann

Hilmar Dohles

Claudia Glenske

Willi Nagel

Karl-Heinz Lust

Peter Brenner

Karl Harter

Gunter Schepp

J&uuml;rgen Kunze

Sebastian Weber

Carsten Möller

Jurgen Kunze

Fritz Dettman

Wulf Andra

Heike Bischoff

Torsten Schönbach

Joerg Traute

Markus Dickerhof

Harald Waltenberger

Andreas Glathe

Michael Lorenz

Herbert Seemann

Andreas Hütten

Günter Müller

Jörg Traute

Josef Gentischer

Wolfgang Fritz

A magnetic field sensor apparatus for determining two or three components of a magnetic field includes at least one Wheatstone bridge with two half-bridges, wherein each half-bridge includes at least two bridge resistors, and at least one of the two bridge resistors is a magnetic-field-sensitive resistor with respect to a magnetic field component in an X/Y magnetic field sensor plane. Arranged symmetrically between the two magnetic-field-sensitive bridge resistors is a ferromagnetic flux concentration element which generates magnetic field components which are anti-symmetric with respect to a Z magnetic field component oriented perpendicular to the X/Y magnetic field sensor plane and are in the X/Y magnetic field sensor plane. A coordinate aspect proposes a method for determining a two-dimensional or three-dimensional orientation of an external magnetic field by such a magnetic field sensor apparatus.

Multicomponent magnetic field sensor

A sensor assembly for determining a spatial position of a first part relative to a second part has at least one magnet disposed on the first part. The magnet generates a magnetic field that extends to the second part. The sensor assembly further has a pair of magnetic field sensors arranged at a spatial distance from each other on the second part. The magnet is positioned in an interval defined by the spatial distance between the magnetic field sensors. The magnetic field sensors each produce an output signal depending on the magnetic field. The output signals of the two magnetic field sensors are combined to form a common sensor signal related to the spatial position of the first part relative to the second part. The output signals of the two magnetic field sensors essentially represent a direction of the magnetic field at the location of the respective magnetic field sensors.

Sensor assembly for determining a spatial position of a first part relative to a second part

The assembly for measuring at least one component (x, y, z) of an applied magnetic field (H) including a surface area made of soft-magnetic material that is applied in the chip plane and separated into two partial regions () by a gap (). The gap () is composed of gap sections having different longitudinal directions, and magnetic field sensitive elements () are accommodated in one or more gap sections disposed parallel to each other. The sensitivity direction () of the magnetic field sensitive elements () and the connecting line (&#x2033;) of the outer gap openings can form angles of 45&#xb0; or 90&#xb0;, and several surface areas can be present in the chip plane in order to completely capture all magnetic field components (x, y, z). Magnetoresistive sensor elements can advantageously be utilized as magnet-sensitive elements ().

Assembly for measuring at least one component of a magnetic field

Disclosed is an arrangement for high-resolution determination of positions on linear or circular ferromagnetic measuring rods () that have a teeth structure, said arrangement providing reliable results in an environment affected by magnetic interference. For this purpose, a magnetic field sensor () is placed at the point where the field of a permanent magnet () is at a maximum and is mounted across from the measuring rod () in such a way that the soft magnetic material of the measuring rod causes the field to strengthen further. The obtained field strength is sufficient to be able to use multilayer GMR sensors in which the resistance changes by more than 40 percent, thus allowing a high signal amplitude to be used for greater position resolution.

Arrangement for scanning a linear or circular measuring rod made of ferromagnetic material

A ball and socket joint with integrated angle sensor, especially for use as a vehicle level control in the chassis of a motor vehicle. The ball and socket joint has a ball and socket joint housing (), a ball pivot () mounted in the ball and socket joint housing (), a bipolar field transducer () arranged at the joint ball () of the ball pivot (), and at least one magnetic field direction sensor (), which is arranged at the ball and socket joint housing () and interacts with the magnetic field generated by the field transducer (), wherein only one pole of the bipolar field transducer () is arranged on the surface of the ball.

Ball-and-socket joint with an angle sensor

The invention relates to a system for pulse magnetizing high-precision magnetic scales. The system comprises a shaped current conductor () and a pulse current source () that is composed of a capacitor bank (), a transfer switch () and a control unit (). The compact set-up of the system is the prerequisite for a power circuit that has such a low resistance that the required high pulse currents are obtained at supply voltages of below 60 V. The transfer switch is an H bridge with four switches () that contain equal numbers of MOS transistors connected in parallel. The short pulse times that are achieved using the MOS transistors allow the use of shaped current conductors with which magnetized areas can be produced with a very high precision. The inventive system provides a means for saving components, electric power and time by a factor of up to 100.

System for writing magnetic scales

In at least one measuring rod of the length measurement system the direction of magnetization lies in the plane of its cross-section which is perpendicular to the direction of measurement and forms a magnetization pattern. In the simplest case the magnetization of the cross-section is homogeneous. As one advances in the direction of measurement the magnetization pattern is increasingly rotated in relation to the starting end of the measuring rod. This magnetization results in a magnetic field whose direction is also continuously rotated as one advances in the direction of measurement. By means of at least one magnetic field sensor which responds to the direction of the magnetic field the prevailing field angle for each position is determined and can be clearly assigned to the position for a multitude of different variants of the length measurement system.

Length measurement system with at least one magnetic measuring rod

The invention relates to a method for evaluating signals while eliminating an interference signal on magnetoresistive sensor elements which is preferably proportional to the zero offset. The sensor elements can form a sensor element array such as a sensor bridge. According to the invention, the direction of magnetization of the sensor elements is modulated or shifted by applying a magnetic pulse field of a modulated or variable direction, and the output signals of the sensor elements or of the sensor element array are fed to a differential amplifier. Due to the modulation or shift of the operating voltage of the sensor bridge, the modulation or shift resulting at the same time as the magnetization of the sensor elements, a signal often arises which includes a direct component that is proportional to the magnetic field to be measured, and has an alternating component that is proportional to the offset voltage of the sensor element array. The latter is minimized by a feedback or is adjusted to zero. The bandwidth, with which the direct voltage that is proportional to the magnetic field to be measured can follow changes of the input signal, is greater in magnitude than the magnetization frequency of the sensor elements.

Method for evaluating signals of magnetoresistive sensors with high band width

An electrically assisted power steering system for motor vehicles includes an input shaft (,), which is operatively connected to a steering wheel, for transmitting a steering torque required to steer the vehicle wheels that are to be steered. An output member is operatively connected to the wheels to be steered. A servomotor (,), by which an auxiliary force can be exerted on the input shaft (,) or the output member, is disposed in the power steering system. The input shaft (,) and the output member are connected to one another via a torsion bar (,). A detection unit for detecting a steering torque acting on the input shaft (,) includes one magnetic ring (,) each, connected to the input shaft (,) and the output member, and one associated sensor (,) each. Each magnetic ring (,) has the same number of magnetic pole pairs. Each magnetic ring (,) is assigned a sensor (,), structurally connected to the housing, by which both the steering torque and the rotary speed of the input shaft (,) are detected.

Electrically assisted automotive power steering system

Sensor chip with magnetoresistive wheatstone bridges for determining

A sensor assembly for measuring current I.sub.o is disclosed. The sensor assembly includes four magnetoresistive resistors (1, 2, 3, 4) arranged to form a Wheatstone bridge. The bridge is disposed over a U shaped conductor 14. The resistors are arranged so that two resistors (1,2) forming one bridge branch are disposed over one leg of the conductor and the two resistors (3,4) forming the other bridge branch are disposed over the other leg of the conductor. Each resistor is formed out of a number of magnetoresistive strips (1', 2', 3', 4'). The magnetoresistive strips forming the individual bridge branch resistors are interleaved so as to ensure the resistors forming each bridge branch have substantially the same temperature. When current I.sub.o is applied to the conductor, the equal and opposite magnetic fields that develop around the individual bridge branches cause the Wheatstone bridge to produce a signal U.sub.a that is a function of the current.

Sensor assembly

To measure magnetic field gradients is difficult because sensor elements available for this have only a limited linearity range due to their sensitivity which is strongly dependent on the temperature and on auxiliary-field magnetic fields and furthermore this sensitivity has a significant sample dispersion. Whereas now the arrangement of a a Wheatstone bridge with magnetoresistive resistors is such that on the one hand two symmetrical areas are provided, in each area of which a resistor of a bridge branch is arranged, and that moveover all other building elements are also designed with a high degree of symmetry. With this a symmetrical temperature gradient is created in the sensor chip, which gradient does not influence the output signal of the bridge. A temperature-dependent zero-point drift does also not exist. The changeable resistor needed for trimming is as the single singular structural part directly arranged on the central axis and also does not interfere with the measurement. The arrangement is particularly suited for the potential-free measurement of the current intensities.

Sensor assembly for measuring current as a function of magnetic field

Magnetic field sensor constructed from a remagnetization line and one

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Wetzlar, Germany

Uwe Loreit