JP2011059130A - Position detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position detector which has only one inherent pulse wire, while having two induction coils, in the simplest form of embodiment. <P>SOLUTION: In this position detector, for example, any information required for count is simultaneously available from both magnetic reversal direction and magnetic reversal trigger direction of the pulse wire, together with finally determined and memorized position and polarity. One detector like this uses memory elements with lower energy request such as FRAM and similarly operates without external energy. In order to enable use of such one position detector even at a high temperature, EEPROM can also be equipped. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a position detector that detects translational and / or rotational movement through the use of ferromagnetic elements.

  This type of ferromagnetic element is in the form of a so-called pulse wire motion detector according to US Pat. No. 4,364,013 and in the form of a Wiegand sensor from DE 4,107,847 C1 and DE 2,817,169 C2. Is known. In these cases, for example, a pulse wire of ferromagnetic material is surrounded by a sensor coil. Magnetic regions (also called magnetic domains or “weiss” regions) in ferromagnetic materials are initially oriented in a random direction, but can be directed into a single magnetic domain under the influence of external forces. When an external magnetic field of a certain direction and strength is applied, this magnetic domain immediately reverses or “flips”. As a result, a voltage pulse is generated in the sensor coil that can be tapped as an output signal.

  In known designs in the form of rotational angle sensors (see eg EP 0,724,712 B1), switching and resetting magnets are made through these pulse wires, some of which are distributed around the circumference, As a result, the magnetic field of one pole and then the opposite pole continues through each of the pulse wires. As a result of all the magnetic domains of each pulse wire being remagnetized, voltage pulses of a defined duration, amplitude and polarity are generated in the sensor coil. An electronic counting circuit evaluates these voltage pulses. The reset magnet generates a magnetic field of opposite polarity, which reverses the magnetic domain of the pulse wire, so that the pulse wire in question is ready to trigger a new pulse. This mode of operation is known as “asymmetric”. In symmetric mode, pulses that can be evaluated are also generated during the reset phase.

  As explained in EP 0,724,712 B1 mentioned above, at least two of these sensors distributed around the circumference in the direction of motion are not only a full rotation of each of the axes of rotation. By taking into account the unique position difference between the set and reset processes, it is also possible to determine the direction of rotation and uniquely associate the generated voltage pulse with the associated angular position of the rotating axis Can do.

  Since at least two sensors must be distributed around the circumference, it is cumbersome to build such a system because the pulse wire sensor is always of a certain size. This means that it is impossible to realize a rotation counter with a small diameter. These sensors are also relatively expensive.

  Using this type of position detector with only a single sensor, the rotation of the shaft and its direction of rotation can be determined. In this case, the sensor is designed as a Vigant wire, which is assembled at an angle with respect to the direction of motion of the section of the shaft, with a magnetic pole positioned opposite the Vigant wire. As such, the wire can generate orientation-dependent pulses (compare DE 2,817,169 C2 referred to above).

  The drawback of such an arrangement is that it is possible to recognize the direction of rotation, but that a given polarization can only detect the direction of rotation that is predetermined by that polarization. That is, only one rotation direction can be determined.

  Therefore, at least two such sensors with an associated evaluation circuit are needed so that both directions of rotation of the shaft can be determined. Furthermore, such an arrangement has the disadvantage that the energy output is very low under certain conditions, since the angle between the direction of motion and the direction of the sensor plays a decisive role. This type of arrangement therefore makes it difficult to work without an external energy source.

US 4,364,013 DE 4,107,847 C1 DE 2,817,169 C2 EP 0,724,712 B1 EP 0,658,745

  The problem of the present invention is to provide a remedy for this situation.

  In ferromagnetic materials, the interaction of the magnetic moments of adjacent atoms with different magnetization directions is so strong that the moments align with each other in a small spatial area, the so-called “weiss” region. These regions are separated from their counterparts by a transition layer known as a “Bloch” domain wall. It has been discovered that a single permanent domain having a uniform magnetization direction can be obtained, for example, by mechanically pulling a ferromagnetic wire. When this type of magnetic domain is introduced into an external magnetic field of constant strength and direction, the magnetic domain does not invert as a whole and instead the unitary magnet has a certain starting position (preferably one end of the wire) Starts to reverse, and proceeds in a domino fashion in the direction toward the external magnetic field. The inversion wave thus generated in the ferromagnetic element has a finite velocity, which is sufficiently faster than that of the exciter magnet and can be referred to as “instantaneous inversion” of the magnetic domain.

  By utilizing the physical relationship described above for a position detector of the type of interest, comprising at least one exciter magnet, a single ferromagnetic element (FE), at least one induction coil, and In accordance with the present invention with a detector having at least one additional sensor element to determine information regarding the polarity and position of the exciter magnet, the above mentioned problem is realized and a single ferromagnetic element (FE) is triggered. The set of information that is available at this point is all that is needed to determine the direction of motion of the exciter magnet.

  In a particularly simple variant of the invention, the action of the Bloch domain wall through the ferromagnetic element makes it possible to detect the position of the exciter magnet by determining the direction in which the remagnetization of the ferromagnetic element is triggered. To. This remagnetization can be caused from either one of the two end faces of the element.

  However, the remagnetization trigger direction is not to be confused with the direction of the remagnetization itself, in which the Weiss region is represented by a “flip” pole to it. In this case, the remagnetization direction has the effect of giving the problem area the same polarity as the trigger pole of the exciter magnet.

  In the case of a continuously rotating shaft, the amount of kinetic energy generated when the unit magnet changes its direction in the direction of the external magnetic field is sufficiently large, so that the electric energy for the signal pulse from the coil assigned to the ferromagnetic element As well as the energy for the counting circuit and Hall sensor can be obtained.

  Once the current position and polarity of the exciter magnet EM are known, they can be associated with the most recently stored position and polarity values. This provides all the information necessary to determine the exciter magnet EM and the direction of motion of the rotating shaft to which the exciter magnet EM is permanently connected.

  In order that the invention can be more clearly understood, the invention will be described below on the basis of a rotation counter.

In the general case characterized by one exciter magnet and half-rotation resolution, the rotation counter system is completely described by the four base states of the exciter magnet, which are the most recent for the magnet. Stored data, ie Z1. ) Arctic to the right of the baseline,
Z2. ) The North Pole to the left of the baseline,
Z3. ) Antarctica to the right of the reference line, and Z4. It can be combined in various ways with the South Pole to the left of the baseline.

  When using only one pulse wire and induction coil according to the present invention, these four states can be combined with each other in various ways to form three groups of two. The group present in the actual case depends on the direction in which remagnetization is triggered.

First group: Both trigger directions of remagnetization are defined. Please refer to FIG. 1, FIG. 2 and FIG.
a. ) North pole to the right of the reference line L or South pole to the left (Z1 or Z4);
b. ) North pole on the left of the reference line L or South pole on the right (Z2 or Z3)

  The position of the exciter magnet EM can now be determined by measuring the direction in which remagnetization is triggered using an additional sensor element, for example a second induction coil or a Hall sensor. When the second coil SP2 is provided over the ferromagnetic element FE, the measurement is performed directly. If the Hall sensor HS is used, the measurement is performed indirectly. When the Hall sensor HS is used, the polarity of the exciter magnet EM detected by the Hall sensor is irrelevant and the only important thing is whether the Hall sensor is excited or not. The polarity of the exciter magnet EM can always be obtained from the polarity of the voltage pulse by measuring the remagnetization direction using the induction coil SP1 or SP of the ferromagnetic element FE.

Second group: Only one trigger direction of remagnetization is defined. Please refer to FIG.
a. ) The north pole on the right or the north pole on the left of the reference line L (Z1 or Z2);
b. ) Right south pole or left south pole of reference line L (Z3 or Z4)

  In this case, the position of the exciter magnet EM is always determined directly by the Hall sensor, ie by whether the Hall sensor is excited or not. Irrespective of this, the polarity of the exciter magnet EM can be determined by measuring the remagnetization direction using the induction coil SP.

Third group: The remagnetization trigger direction is not specified. Please refer to FIG.
a. ) Above reference line L and right north pole or below reference line L and right south pole (Z1 or Z2);
b. ) Below the reference line L and the right north pole or below the reference line L and the right south pole (Z4 or Z3)

  The corresponding polarity is evaluated as a function of the location of the Hall sensor HS, ie whether it is on the right side (as shown in FIG. 5) or on the left side. The polarity of the exciter magnet EM is here given directly by the Hall sensor HS. The position of the exciter magnet EM (upper or lower north pole or south pole) is indirectly determined by measuring the remagnetization direction.

  All solutions are mathematically equivalent and have the same technical value.

As a result of the inventive procedure described above, it is possible to realize a position sensor with the simplest imaginable mechanical design comprising only a single ferromagnetic element, where the single ferromagnetic element is zero. Works well in both directions of exciter magnet motion, even at near speeds and after the standard power supply fails. It should be noted here that all the information required to determine the polarity and direction of motion of the exciter magnet EM is available at the time T _S , ie the time when the ferromagnetic element FE is triggered. That is. Therefore, in addition to the stored data, all necessary signals are present at the inductive coil in question and / or the output terminal of the Hall sensor. To achieve this goal, it is necessary that the ferromagnetic element FE, the Hall sensor HS, and the exciter magnet or magnet EM be arranged in a very special spatial arrangement with respect to each other, for example in one place.

  The position detector with an optimally simplified design is also for an evaluation circuit comprising at least one counting device, a non-volatile memory and a capacitor, as well as energy for the output signal from the sensor coil SP or sensor coils SP1, SP2. The energy of can also be obtained.

  Further features of the invention can be derived from the dependent claims.

  The invention will be described below on the basis of five exemplary embodiments which are shown somewhat schematically in the drawings.

1 is a schematic illustration of a position detector design according to the present invention having one ferromagnetic element, two assigned induction coils, and two ferromagnetic flux conducting pieces. 4 is a schematic diagram of a position detector design according to a second exemplary embodiment of the present invention having one ferromagnetic element, one induction coil, a Hall sensor, and two ferromagnetic flux conductors. 6 is a schematic diagram of a position detector according to a third exemplary embodiment of the present invention having one ferromagnetic element, one induction coil, a Hall sensor, several exciter magnets, and two ferromagnetic flux conducting pieces. is there. Fig. 6 is a schematic illustration of a position detector according to a fourth exemplary embodiment of the present invention having one ferromagnetic element, one induction coil, and a Hall sensor. A position detector according to a fifth exemplary embodiment of the present invention having one ferromagnetic element, one induction coil, a Hall sensor, and two ferromagnetic flux conducting pieces arranged 180 degrees crossing each other FIG. FIG. 6 is a block circuit diagram of an evaluation circuit suitable for use in the embodiment according to FIGS. FIG. 5 shows an arrangement of position detectors corresponding to FIG. 5, and the rotation axis of the exciter magnet is rotated by 90 ° with respect to the arrangement according to FIG. FIG. 7 shows the arrangement of position detectors corresponding to FIG. 7, the rotation axis of the exciter magnet being rotated 90 ° with respect to the arrangement according to FIG. 5, and two exciter magnets are shown for clarity. .

  In the embodiment of the position detector shown in FIG. 1, the moving object is a shaft 10 and the shaft 10 rotates in the direction indicated by the arrows R1 and R2, ie either clockwise or counterclockwise. Can do. An exciter magnet EM having a north pole N and a south pole S is provided so that the rotation of the shaft 10 can be counted. The ferromagnetic element FE can be influenced by the magnetic field generated by the exciter magnet EM by the ferromagnetic flux conducting pieces FL1 and FL2. The ends 14 and 15 of the flux conductors lie on an arc represented by the path of the exciter magnet EM, while the ends 16 and (on the left of the reference line L on the FE) and (on the FE) The end 17 (located to the right of the reference line L) faces the end face of the ferromagnetic element FE.

  A ferromagnetic element FE that is parallel to the direction of motion of the exciter magnet is surrounded by two sensor coils SP1 and SP2. As the exciter magnet EM passes through the ferromagnetic element FE, the exciter magnet remagnetizes the element, so that a voltage pulse of the corresponding polarity is generated. These pulses can be tapped out from the output terminals 22 and 23 of the two coils. The second induction coil SP2 now serves as an additional sensor element that determines the direction in which remagnetization is triggered. The direction in which remagnetization is triggered and thus the position of the exciter magnet EM can be derived from the time shift between the voltage maxima of the two coils. Strictly speaking, only coils with a logic state “1”, that is, coils that reach their maximum voltage for the first time need to be evaluated. The other coils have not yet reached their maximum value at this point and are therefore evaluated to be in the logic state “O”. The pulse wire here serves as a ferromagnetic element.

  In the embodiment according to FIG. 2, elements corresponding to those of FIG. 1 have the same reference numbers.

  In contrast to FIG. 1, only one sensor coil SP is assigned to the ferromagnetic element FE. In order to be able to determine the position of the exciter magnet when the exciter magnet passes by the ferromagnetic element, here a Hall sensor HS is provided as an additional sensor element, and at the output 24 of the Hall sensor HS: There is a signal that can be tapped out or there is no signal. The polarity is determined here by the coil SP of the ferromagnetic element FE, as in FIG. The polarity determined by the Hall sensor is irrelevant to the evaluation, but is used as surplus information to monitor device behavior.

Thus, for determining the polarity and direction of movement of the exciter magnet, the complete set of available information at the time T _S, the data in the non-volatile memory, and the signal output terminal of the induction coil, or induction It consists of signals from the output terminal of the coil and the output terminal of the Hall sensor.

  The position detector embodiment according to FIG. 3 is the same as that of FIG. 3, except that the shaft 10 here comprises four exciter magnets EM1-EM4, 90 ° apart, of alternating polarity, in order to improve the resolution. Having elements corresponding to those of the exemplary embodiment described in. Therefore, when the shaft 10 rotates, first the north pole and then the south pole will traverse each of the end faces of the ferromagnetic element FE by means of the flux conducting pieces FL1 and FL2. The Hall sensor required to determine the position of the exciter magnet is here assigned to the end of the exciter magnets EM1-EM4 facing away from the ferromagnetic element.

  The embodiment of the position detector according to FIG. 4 has the same elements as those of the previously described embodiment, except that there are no flux conducting pieces. This variant mainly makes use of the fact that the ferromagnetic element FE has already been triggered before the exciter magnet EM is aligned with the ferromagnetic element FE. The detection range of the Hall sensor HS required for determining the position of the exciter magnet EM is calculated so that the detection range extends to the reference line L approximately.

  The embodiment of the position detector according to FIG. 5 also corresponds to the previously described embodiment, except that the ends of the flux conducting pieces FL1 and FL2 facing the exciter magnet are arranged 180 ° apart. Has an element. The Hall sensor required as an additional sensor element for determining the polarity of the exciter magnet is here at a right angle to a reference line L passing through the center of rotation of the shaft 10 and the ferromagnetic element is When triggered, it is arranged to detect the corresponding pole of the exciter magnet EM. This always occurs at a constant angle α before the poles are aligned with the flux conductors. The position of the exciter magnet EM is determined by the coil of the ferromagnetic element FE that measures the remagnetization direction. This variant according to FIG. 5 can be operated with a very small exciter magnet EM, especially when the intended flux conducting piece is also used in the form of a magnetic lens that bundles the magnetic flux.

  In the exemplary embodiment according to FIGS. 1-5, a design is shown in which the exciter magnet EM and the ferromagnetic element FE are in the same plane with respect to the axis of rotation. That the ferromagnetic element FE and the exciter magnet EM are on different planes (as shown in FIG. 7) or on the same plane (as shown in FIG. 8) but parallel to the axis of rotation. Of course, it is possible and in some cases advantageous.

  The input terminals 32, 33 of the evaluation circuit, indicated generally by the reference numeral 30, are connected to the sensor coils SP1 and SP2 or the coil SP and Hall sensor. This type of circuit is assigned to each of the position sensors according to FIGS. 1 to 5 and FIGS. FIG. 6 shows a block circuit diagram of this evaluator. The recognition circuits 34 and 35 are provided at the subsequent stage of the input terminal. The energy supplying capacitor C is also connected to the input 32 by a rectifier D. The signals from the recognition circuits 34 and 35 are evaluated by a counter 38, which has its own non-volatile memory 36. The status of the new counter is obtained based on the history provided in the stored data and the information provided by the recognition circuits 34, 35 regarding the current position and polarity of the exciter magnet. This new status is then stored in a non-volatile memory unit, usually a FRAM unit.

  The energy for the evaluation circuit is usually obtained from signals sent by the induction coils SP, SP1 and SP2. If only one induction coil SP is used, the energy for the Hall sensor is also supplied by this coil.

  The connection line 41 is a part of the voltage supply unit for the evaluation circuit described above. Data is read out via the tap 39 and the interface 40. If provided, the line 42 serves to introduce energy from the outside, especially when an EEPROM is used in addition to the FRAM. EEPROM usually allows the evaluation circuit to operate at very high temperatures where configuration data in the FRAM will be lost after only a short time.

  Common to the exemplary embodiments described above is that the rotation and / or direction of rotation of the shaft 10 can be detected with a certain accuracy by only a single ferromagnetic element, for example a pulse wire, The pulse wire is to make available enough energy to supply the evaluation circuit and the Hall sensor as an additional sensor element. In the simplest variant of this arrangement of pulse wires (according to that variant, the two ends of the pulse wire are equivalent from the point of view of the measurement technique), the generated voltage pulses are triggered excitation Contains information about both the position and polarity of the magnet.

Another essential point is that all the information regarding the direction of triggering remagnetization of the ferromagnetic element, the triggering pole of the exciter magnet EM, and the most recently stored exciter magnet polarity and position relative to the axis of rotation, the trigger point T _S of the ferromagnetic element, that is, it is simultaneously available in the response time of the selected element.

  The capacitor C of the evaluation circuit is provided at least for accumulating supply energy obtained from the signal until the signal is evaluated and the counter value is stored in the non-volatile memory unit.

  It would be possible to use other types of ferromagnetic elements instead of pulse wires or Wiegand wires if the conditions for “instantaneous reversal” of the Weiss region are met.

  To avoid misunderstanding, it should be pointed out that ignoring the stray magnetic field, the ferromagnetic element FE is characterized by the presence of only one magnetic input and one magnetic output. It is conceivable that there may be any number of parallel and / or series obstructions between the input and output, which is a departure from the idea of the present invention as a single element. Does not indicate.

  Instead of Hall sensors, other sensors such as field plates could be used to determine the exciter magnet polarity or position. It is also possible to prepare the exciter magnet so that the position and / or polarity of the exciter magnet can be determined by capacitive measurement instead of by a Hall sensor. For example, as described and shown in EP 0,658,745, it is also possible to use the position detector described above with a precision rotation angle sensor in the form of a so-called “multi-turn”. In this case, the reference line L corresponds to the zero point of the precision rotation angle sensor used.

  For example, using a Vigant wire, synchronization with a precision rotation angle sensor requires the availability of precise data regarding the state of magnetization of the ferromagnetic element FE. For this purpose, for example, an arrangement with two coils according to FIG. 1 is suitable. By supplying an external current to one of the coils, eg, coil SP1, it is possible to trigger a voltage pulse in the second coil, eg, coil SP2, as a function of the magnetization of the ferromagnetic element. This is also possible for two coils arranged so as to overlap each other. It is also possible to trigger the voltage pulse with a short current pulse or a current with a slow linear rise, in which case only a single coil SP would be required.

10 axis 14, 15, 16, 17 end 22, 23, 24 output terminal 30 evaluation circuit 32, 33 input terminal 34, 35 recognition circuit 36 nonvolatile memory unit 38 counter 39 tap 40 interface 41 connection line 42 line α trigger angle C Capacitor D Rectifier EM, EM1, EM2, EM3, EM4 Exciter magnet FE Ferromagnetic element FL1, FL2 Ferromagnetic flux conducting piece HS Hall sensor L Reference line N North pole R1, R2 Arrow S South pole SP, SP1, SP2 Sensor coil SE when the additional sensor element _{T S} ferromagnetic element FE is triggered Z1, Z2, Z3, Z4 exciter magnets ground state

Claims (25)

A detector for detecting movement,
A movable exciter magnet (EM),
A single ferromagnetic element (FE) having a Weiss region and a Bloch domain wall;
An inductive element (SP1) surrounding the ferromagnetic element (FE);
A second inductive element (SP2) surrounding the ferromagnetic element;
With
When the ferromagnetic element (FE) is triggered and remagnetized by the exciter magnet (EM), the inductive element (SP1) provides a first output (22) in time (T _S ). And
When the ferromagnetic element (FE) is triggered and remagnetized by the exciter magnet (EM) without further movement of the exciter magnet (EM), the second inductive element (SP2) is Providing a second output (23) at substantially the same time as the first output at the time T _S rather than exactly at the same time;
The first output (22) and the second output (23) are shifted in time relative to each other, and the time shift and generation of the first output (22) and the second output (23). The detector determines the direction, polarity, and position of the exciter magnet (EM) in which remagnetization of the ferromagnetic element is triggered.   The detector according to claim 1, wherein the movable exciter magnet is a rotatable exciter magnet (EM) and the detector is adapted to detect rotational movement. The detector further comprises an evaluation circuit (30) including a counter (38), a capacitor, and a non-volatile memory unit (36),
The detector according to claim 1, characterized in that the exciter magnet (EM) is rotatable and the detector is adapted to detect rotational movement. The polarity and direction of motion of the exciter magnet (EM) at the time (T _S ) are the data in the non-volatile memory unit (36), the first output (22) and the second output (23). The detector according to claim 3, wherein the detector is determined from:   The energy supply for the evaluation circuit (30) is obtained from the first signal and the second signal used to detect the position and / or polarity of the exciter magnet. The detector according to claim 3.   The detector according to claim 3, characterized in that the non-volatile memory unit (36) is a FRAM and / or an EEPROM.   The detector according to claim 1, wherein the ferromagnetic element (FE) is a pulse wire.   The inductive element (SP1) is a coil used in combination with the second inductive element (SP2) to measure the magnetization direction of the ferromagnetic element (FE). The detector described.   The second inductive element (SP2) is a coil that is wound over the ferromagnetic element (FE) and is used to determine the direction in which remagnetization of the ferromagnetic element (FE) is triggered. The detector according to claim 1, wherein there is a detector. The inductive element (SP1) is a coil;
The second inductive element (SP2) is a coil;
The inductive element (SP1) and the second inductive element (SP2) are used to determine a direction in which remagnetization of the ferromagnetic element (FE) is triggered. The detector described.   The at least one ferromagnetic flux conducting piece (FL1 and / or FL2) for guiding and / or bundling the magnetic flux is arranged close to the ferromagnetic element (FE). Item 2. The detector according to Item 1.   The detector according to claim 1, characterized in that the inductive element (SP1) can supply an external current pulse that serves to cause or continue the biasing of the ferromagnetic element (FE). . A detector for detecting movement,
A movable exciter magnet (EM),
A single ferromagnetic element (FE) having a Weiss region and a Bloch domain wall;
An inductive element (SP) surrounding the ferromagnetic element (FE);
A sensor element (SE) tuned to the ferromagnetic element (FE);
With
When the ferromagnetic element (FE) is triggered and remagnetized by the exciter magnet (EM), the inductive element (SP1) provides a first output (22) in time (T _S ). And
When the ferromagnetic element (FE) is triggered and remagnetized by the exciter magnet (EM) without further movement of the exciter magnet (EM), the sensor element (SE) _S provides a second output (24) at substantially the same time as the first output, not exactly at the same time,
A detector, characterized in that the direction in which remagnetization of the ferromagnetic element is triggered by the exciter magnet (EM) is established by whether the sensor element (SE) is excited.   The detector of claim 13, wherein the movable exciter magnet is a rotatable exciter magnet (EM) and the detector is adapted to detect rotational motion. The sensor element is a Hall sensor (HS),
The polarity and direction of motion of the exciter magnet (EM) at the time (T _S ) is the data in the non-volatile memory unit (36), the first output (22) and the second output (24). Determined from
15. Detector according to claim 14, characterized in that the second output (24) is generated by the Hall sensor (HS).   The energy supply for the evaluation circuit (30) is obtained from the first signal and the second signal used to detect the position and / or polarity of the exciter magnet. Item 16. The detector according to Item 15.   16. Detector according to claim 15, characterized in that the non-volatile memory unit (36) is a FRAM and / or an EEPROM. The detector further comprises an evaluation circuit (30) including a counter (38), a capacitor, and a non-volatile memory unit (36),
14. A detector according to claim 13, wherein the movable exciter magnet (EM) is rotatable and the detector is adapted to detect rotational movement.   14. Detector according to claim 13, characterized in that the ferromagnetic element (FE) is a pulse wire.   14. Detection according to claim 13, characterized in that the inductive element (SP) is a coil used in conjunction with the sensor element (SE) to measure the magnetization direction of the ferromagnetic element (FE). vessel.   14. The detector according to claim 13, wherein the sensor element (SE) is a Hall sensor (HS) for measuring the polarity of the exciter magnet (EM) and determining the position. The exciter magnet moves in two rotational directions;
14. Detector according to claim 13, characterized in that the exciter magnet (EM) has an axis mounted parallel to the ferromagnetic element (FE). The exciter magnet moves in two rotational directions;
The detector according to claim 13, wherein the exciter magnet (EM) has an axis mounted orthogonal to the ferromagnetic element (FE).   The at least one ferromagnetic flux conducting piece (FL1 and / or FL2) for guiding and / or bundling the magnetic flux is arranged close to the ferromagnetic element (FE). Item 14. The detector according to Item 13.   The detector according to claim 1, characterized in that the sensor element (SE) is capable of supplying an external current pulse which serves to cause or continue the bias application to the ferromagnetic element (FE). .

Images