DE102016204439A1 - Capacitive angle sensor - Google Patents

Abstract

The present invention relates to a capacitive angle sensor which has at least three first electrodes statically arranged in a plane about an axis of rotation and a second electrode rotatable about the axis of rotation and arranged in a second to the first parallel plane with respect to the first electrodes. The second electrode covers at least two of the first electrodes in each case at least partially to form a capacitance. The electrodes are dimensioned and arranged such that the second electrode has a constant overlap with a middle one of the three first electrodes in a rotational angle range which can be used for the measurement, and the overlap with the other two first electrodes changes in opposite directions upon rotation in this rotational angle range. The three first electrodes are electrically connected in a measuring circuit so that they form two circuit capacitances, in each case between the middle and one of the other two first electrodes. The measuring circuit is designed so that it delivers a dependent of the two circuit capacitance measurement as a measure of the angle of rotation. The proposed angle sensor can be implemented with a small footprint and enables reliable measurement results over an angle measuring range of ≥ 100 °.

Description

Technical application

The present invention relates to a capacitive angle sensor comprising at least three first electrodes arranged statically in a first plane about a rotation axis and a second electrode rotatable about the rotation axis arranged in a second to the first parallel plane with respect to the first electrodes and at least two of the first electrodes are each at least partially covered to form a capacitance.

Capacitive angle sensors can be used in many technical fields, in which the angular position of two components, for example of finger links of a hand prosthesis in medical technology, is to be detected. Capacitive angle sensors offer the advantage of a small installation space compared to magnetic or potentiometric measurement techniques.

The basic physical principle of a capacitive sensor is based on the operation of a capacitor. The capacitance C of a simple area capacitor depends on its area, the distance between the plates and the intervening dielectric: A = ε ₀ · ε _r · A / l

Here, ε _{0 is} the absolute dielectric constant, ε _r the relative dielectric constant of the dielectric present between the plates, A the overlapping surface and l the distance of the plates. Now, if the distance of the plates, the position of the plates to each other or the intervening dielectric changes, this can be detected by the changing capacitance of the capacitor. An example of a variable capacity capacitor is a variable capacitor. In a rotary capacitor, the most semi-circular electrodes can be shifted from each other, whereby the surface of the capacitor and thus its capacity is changed. A variable capacitor can thus also be used as an angle sensor. Corresponding rotation angle sensors are commercially available.

State of the art

From the EP 1 033 578 A2 a capacitive angle sensor is known, which in one embodiment has three first electrodes arranged statically about a rotation axis in a first plane, over which a second electrode rotatable about the rotation axis is arranged in a second plane parallel to the first plane, the at least two of the first electrodes each at least partially covered to form a capacity. The two outer static electrodes form excitation electrodes which are subjected to time-shifted voltage pulses for the measurement. The instantaneous angular position and direction of rotation can then be derived from the voltage pulses received via the middle static electrode.

The object of the present invention is to provide a capacitive angle sensor which requires the smallest possible installation space and can reliably detect the angular position over an angular or measuring range of ≥ 100 ° with simple signal evaluation.

Presentation of the invention

The object is achieved with the capacitive angle sensor according to claim 1. Advantageous embodiments of the angle sensor are the subject of the dependent claims or can be found in the following description and the embodiments.

The proposed angle sensor has at least three first electrodes arranged statically in a first plane about an axis of rotation and a second electrode which is rotatable about the axis of rotation and which is arranged in a second to the first parallel plane with respect to the first electrodes. Depending on the angular position, the second electrode at least partially covers at least two of the first electrodes, in each case forming a capacitance. The axis of rotation is perpendicular to the first and second levels. In the proposed angle sensor, the second electrode and the three first electrodes are dimensioned and arranged such that the second electrode has a constant coverage with the middle one of the three first electrodes in a rotational angle range used for the measurement, also referred to below as the measuring range the overlap with the two other first electrodes, also referred to below as outer electrodes, changes in opposite directions during rotation in this rotation angle range. The capacitance between the middle electrode and the second electrode is thus approximately constant over the entire measuring range. The capacitances between the two outer electrodes and the second electrode change in rotation in this Drehwinkel- or measuring range depending on the overlap in opposite directions. In the case of the proposed angle sensor, the three first electrodes are electrically connected in a measuring circuit such that they form two capacitors or capacitors in the measuring circuit, hereinafter referred to as circuit capacitances. One of the circuit capacitances represents the capacitance between the middle and one of the outer electrodes, the other circuit capacitance represents the capacitance between the middle and the other outer electrode. The measuring circuit is designed such that it supplies a measured variable dependent on the two circuit capacitances as a measure of the angle of rotation, wherein a frequency or an electrical voltage amplitude or a difference or a ratio of two frequencies or electrical voltage amplitudes serves as the measured variable.

The first electrodes and the second electrode are preferably each formed as circular segments about the axis of rotation. In a preferred embodiment, the two outer electrodes form two circular segments with an angle α of ≥ 120 °. With suitable dimensioning of the second electrode, this also makes it possible to detect the angular position over an angle of ≥ 100 °. The middle electrode forms a circular segment which has an angle β of preferably 360 ° -2α. The two planes in which the first electrodes and the second electrode are arranged preferably have a spacing of ≦ 50 μm. Between the first and the second electrode, a dielectric film or layer with a relative dielectric constant ε _r > 3 is preferably arranged.

The measuring circuit is formed in the proposed angle sensor in one embodiment in the form of one or two multivibrators in which the two circuit capacitances are integrated. In one variant of the measuring circuit, a multivibrator with a switching frequency influenced by the value of the respective circuit capacitance is provided for each of the two circuit capacitances. In a second variant, only a correspondingly modified multivibrator is used as the measuring circuit, in which the measured variable is the output frequency of the multivibrator. The two circuit capacitances are connected in the multivibrator in such a way that the output frequency of the multivibrator changes more strongly than when only one of the circuit capacitances is used due to the circuit capacitances changing in the opposite direction.

In a further embodiment, a measuring circuit is used which has two amplification branches for an alternating voltage, one of the two circuit capacitors being arranged in each of the amplifying branches. The two amplification branches are preferably dimensioned identically except for the circuit capacitances. The measuring circuit preferably supplies as a measured variable a ratio of the output voltage amplitudes of the two amplification branches. As AC voltage while a square-wave voltage is preferably fed. With different circuit capacitances, the output amplitude of the respective amplification branch then changes, so that conclusions can be drawn from the ratio of the amplitudes to the rotational position of the second electrode.

The proposed capacitive angle sensor allows in the smallest space with appropriate dimensioning of the electrodes, a measurement of the angle of rotation about the axis of rotation at least in the range of about 100 °. When enlarging the two outer first electrodes to a circle segment range of> 120 °, an even larger measurement or angle range can be achieved.

In a particularly advantageous embodiment using a modified multivibrator as a measuring circuit, the information about the angle is output as a frequency. The frequency values can be set in a relatively large range of, for example, 5 kHz to 200 kHz on the dimensioning of the measuring circuit. The modified multivibrator is designed in such a way that it can convert two capacitance values - the two circuit capacitances - which change in opposite directions, into a frequency change. Especially microcomputers or microprocessors are particularly suitable for measuring frequencies.

By averaging in the frequency measurement, for example, the noise can be suppressed. By suitable mechanical or electrical contacts on the angle sensor and the zero position of the measuring range could be easily detected, for example, to suppress a long-term drift or the like.

In the likewise very advantageous embodiment of the measuring circuit with the two amplification branches, the relative change of the amplitudes of the output voltages can be used to determine the angle. As a result, a high common mode rejection is possible, so that production fluctuations or contamination influences can be largely suppressed. The zero position can be derived directly from a measurement in this measurement circuit, as will be explained in more detail in the embodiment.

The proposed angle sensor can be implemented in a very small space with a thickness of <0.2 mm (pure sensor structure without encapsulation or the like) and a diameter of, for example, about 10 mm. This makes it particularly suitable for requirements in which an angle measurement is to be realized in a very space-saving manner. An application example of this is the measurement of the angles of phalanges in a prosthetic hand in the field of medical technology. Of course, however, the proposed angle sensor can be used in all areas in which an angle between two relatively relative to a rotational axis movable components to be measured.

An even larger measuring range can be achieved by an additional similar sensor be achieved, which is offset by about 90 ° to the first sensor and is arranged concentrically on the same axis of rotation.

It is also possible to additionally arrange another 3 static electrodes mirror-symmetrically to the first electrodes in a third plane so that the second electrode lies between the first and third plane. This corresponds to an arrangement of two angle sensors with a common second electrode. As a result, with a suitable connection of these further electrodes, a larger measurement signal can be obtained. For this purpose, the first and the further electrodes are electrically connected in the respective measuring circuit such that the two angle sensors deliver an opposite measuring signal when the second electrode rotates about the axis of rotation. By difference formation of the measurement signals then an overall larger signal is obtained. The difference of the measurement signals also leads to an advantageous common mode rejection. These advantages can also be realized by two separate angle sensors on the same axis of rotation, which then each have separate second electrodes. The first electrodes of the two angle sensors are then in turn electrically connected in the respective measuring circuit so that the two angle sensors deliver an opposite measuring signal when the second electrodes rotate in the same direction around the axis of rotation.

Brief description of the drawings

The proposed capacitive angle sensor will be explained in more detail below with reference to exemplary embodiments in conjunction with the drawings. Hereby show:

1 a schematic representation of the arrangement of the individual electrodes of the angle sensor - separated for both planes;

2 an equivalent circuit diagram of the capacitances of the angle sensor 1 .

3 an equivalent circuit diagram, which additionally shows the circuit capacitance of the angle sensor, which are used in the measuring circuit;

4 an exemplary circuit diagram for a multivibrator, as it can be used in the measurement circuit;

5 an exemplary circuit diagram for a measuring circuit based on a modified multivibrator;

6 an example of a change in frequency as a function of the rotational position of the capacitive angle sensor with the measuring circuit of 5 ;

7 a further exemplary circuit diagram for a measuring circuit of the proposed capacitive angle sensor;

8th an example of the ratio of the maximum peak-to-peak values of the two output voltages in the measuring circuit of 7 depending on the angular position of the angle sensor;

9 another example of the arrangement and dimensioning of the electrodes in the proposed angle sensor;

10 a schematic representation of the arrangement of two of the angle sensors one above the other to expand the angle measuring range; and

11 a schematic representation of an arrangement of two of the angle sensors with a common second electrode.

Ways to carry out the invention

The proposed capacitive angle sensor has at least three static electrodes in a first plane, which are arranged about an axis of rotation extending perpendicular to the first plane. In a second plane parallel to the first plane, a second electrode, which is rotatable about the axis of rotation in the second plane, is arranged opposite to the first electrodes. 1 schematically shows an example of the arrangement and configuration of the first electrode in the first plane and the second electrode in the second plane. The left part of the 1 shows the three first electrodes 1 . 3 . 4 in the first level, the right part of the picture shows the second electrode 2 in the second level. In the present example, the electrodes are each a circle segment around the axis of rotation 5 educated. The electrodes are each on a suitable support with a flat surface, which is formed in the present example with a circular geometry. The carrier with the three first electrodes 1 . 3 . 4 is static while the wearer is using the second electrode 2 around the axis of rotation 5 is rotatably mounted. The possibility of rotation is indicated by the arrows in the 1 indicated. The direction of rotation is freely selectable.

In the proposed angle sensor are the three statically arranged electrodes 1 . 3 and 4 connected to a measuring circuit which in the 1 not shown. The second electrode 2 is not electrically contacted and serves only the capacitive coupling of two of the opposite first electrodes. In the present example, the circle segments of the first electrodes 1 . 3 and 4 each at an angle of about 120 °. The second electrode forms a circle segment with an angle of 240 ° in this example. As a result, covers the second electrode in a zero position of the angle sensor 2 the first two electrodes 1 and 3 Completely. In this example, this corresponds to a zero position of the angle sensor, as in 1 is also indicated.

The electrode 3 is used in the present patent application as a central electrode, the two electrodes 1 and 4 referred to as external electrodes. In the case of the proposed angle sensor, the two carriers with the respective electrodes lie at a distance one above the other, through which in each case a capacitance between the second electrode 2 and the respective first electrode is covered, which covers the second electrode in the respective angular position. The larger the coverage, the larger the corresponding capacity. Thus, the equivalent circuit of the 2 are given, each having the capacitances C ₁₂ between the electrode 1 and the electrode 2 , C ₂₃ between electrode 2 and the electrode 3 and C ₂₄ between the electrode 2 and the electrode 4 includes. For a rotation angle range of 120 ° results for the two capacities C ₁₂ and C ₂₄ opposite behavior. When the carrier rotates, the value of C ₁₂ decreases with the second electrode 2 At the same time, the value of C _{24 increases} due to the change in the coverage between the electrodes 1 and 2 or between the electrodes 2 and 4 , The value of C ₂₃ remains constant in the first approximation, since the overlap of the two electrodes 2 and 3 due to the selected dimensioning of the electrode 2 in the rotation angle range of 120 ° is always the same.

The second electrode 2 in each case two of the first electrodes, which are at least partially covered by it, capacitively couple. Overall, this capacitive coupling between the terminals of the electrodes 1 and 3 respectively. 3 and 4 get two different capacitance values C ₁₃ and C ₃₄ , which change in opposite directions upon rotation due to the change of C ₁₂ and C ₂₄ . The corresponding equivalent circuit diagram is in 3 shown. Where:

Will be between the first electrodes 1 . 3 and 4 and the second electrode 2 used as a dielectric, for example, a Teflon film with a thickness of 25 microns and an ε _r of 3.1, then results in a diameter of the circular disk for the three circle segments of 1 of 12 mm and circle segment angles of 120 ° each with complete coverage by the second electrode 2 each with a capacity of approx. 8 pF.

In order to determine the respective angular position of the second electrode of the proposed angle sensor, different measuring circuits will be exemplified below. 4 in this case shows a multivibrator, such as in the present or in a modified form according to 5 can be used as a measuring circuit or part of the measuring circuit. In such a circuit, switching of the output voltage U_out occurs when the voltage U_n present at the inverting input of the operational amplifier OPV becomes greater in magnitude than U_p. Due to the in 4 this is always ensured, since the voltage U_n at the inverting input of the operational amplifier could theoretically reach the output voltage U_out in the limiting case. Before that, however, the voltage U_n becomes greater than the voltage U_p and this leads to the switching of U_out. Exemplary values for the resistors R1, R2 and R3 in this circuit are R1 = 10 kΩ, R2 = kΩ and R3 = 470 kΩ. GD is a reference voltage in this and the other circuits. The switching frequency is then of the size of the capacitance C1 in the circuit of 4 dependent. If one chooses one of the two capacitors C ₁₃ or C ₃₄ , referred to in the present patent application as circuit capacitance, as the capacitance C1 in the circuit of 4 , it can be concluded from the switching frequency on the size of this capacity. In this case, if necessary, a possible parasitic capacitance of the measuring circuit must be taken into account, which can be determined beforehand. By using two of these multivibrators the 4 each with the circuit capacitance C ₁₃ and C ₃₄ , the opposite change of C ₁₃ and C _{34 can be} advantageously measured as a change in frequency of the respective output voltage U_out. By forming a ratio of the output frequencies of the two multivibrators, the angle can then be derived, even if the absolute values of C ₁₃ or C ₃₄ should change in the same way due to superimposed parasitic effects - eg due to contamination or the like.

However, a modified multivibrator is used particularly advantageously as the measuring circuit in the proposed angle sensor, in which both the circuit capacitors C ₁₃ and C _34, which change in opposite directions, are connected. 5 shows an example of such a measuring circuit. The proposed interconnection according to 5 is particularly favorable here. When the capacitor C ₁₃ (with a relatively large capacitance value) is charged, the charging current is simultaneously reduced by the decreasing capacitor C ₃₄ (total resistance from R 6, R 7 and C ₁₃ becomes larger overall). Overall, this leads to an increase in the time during reloading, that is, to a smaller frequency of U_out. Conversely, the same applies. If C ₁₃ becomes smaller, then it becomes additional Overall, the current for reloading over R6, R7 and C ₁₃ larger, resulting in an overall increase in the frequency of U_out. As a result, the frequency of U_out is additionally changed by the opposing behavior of the two circuit capacitances C ₁₃ and C ₃₄ . Overall, this leads to a larger frequency change and thus to a larger measurement signal compared with the use of the multivibrator according to FIG 4 , Exemplary values for the resistors in this circuit are R4 = 10kΩ, R5 = 10kΩ, R6 = 100kΩ and R7 = 220kΩ.

6 shows a measurement of the frequency of the measuring circuit according to 5 when dimensioning the electrodes of the angle sensor, as in connection with 1 was explained. The diameter of the circular disk with the electrodes was 12 mm in each case. Teflon with a thickness of 25 μm and an ε _r of about 3.1 was used as the dielectric. The capacitance value for C ₁₃ and C _{34 is} in each case a value of 8 pF for each complete coverage. The measurement of 6 was performed over an angular range of 360 °. In the angular range of 100 ° to 210 °, which can be used as the measuring range for a measurement with this angle sensor, an approximately linear course was obtained, the point of 0 ° in 6 not the zero position of the measuring range in 1 equivalent.

7 shows another example of a measuring circuit, as it can be used in the proposed angle sensor. This measurement circuit is similar to a charge amplifier. Here, the angle information is output not as a frequency-coded signal but as an amplitude-modulated signal, ie the peak-to-peak value of the output voltages U1 and U2 contains the information about the rotation angle of the structure according to 1 , The two circuit capacitances C ₁₃ and C ₃₄ in turn change in opposite directions and are used in the two amplification branches of the measuring circuit. In this example, a multivibrator with the operational amplifier OPV1 is used to generate a square wave, which is then connected via the two capacitors C ₁₃ and C ₃₄ to the two operational amplifiers OPV2 and OPV3. Due to the feedback via the capacitors Cr1 and Cr2 and the relatively high-value resistors Rr1 and Rr2, a gain then takes place which essentially represents an AC voltage amplification. Instead of the multivibrator for generating a square wave as an input signal, of course, another circuit for generating an AC voltage or AC voltage source can be used. Exemplary values for the resistors and additional capacitors in this circuit are R1 = 10 kΩ, R2 = kΩ and R3 = 330 kΩ, R4 = 56 kΩ, R5 = 56 kΩ, Rr1 = 680 kΩ and Rr2 = 680 kΩ, C3 = 15 pF , Cm1 = 5 pF, Cr1 = 15 pF and Cr2 = 15 pF.

8th shows results of a measurement with this measurement circuit and an embodiment of the angle sensor with the dimensions already given in the last example. The 8th shows the ratio of the peak-to-peak values of the two output voltages U1pp to U2pp over the rotation angle. Clearly visible is a nearly linear relationship for U1pp / U2pp for an angular range of about 100 ° (rotation angle of 20 ° to 120 °). The formation of the ratio can advantageously also be used, for example, to largely suppress manufacturing differences or other effects which change the two capacitances C ₁₃ and C ₃₄ in the same way. At a defined angular position, U1pp and U2pp are the same size for this measurement circuit. Preferably, this position is used as a reference for the zero position of the measuring range, since it can be found or approached at any time during the measurement by forming the difference U1pp-U2pp. A mechanical stop or other means for determining the zero position are no longer required.

With a smaller design of the angle sensor, for example with six millimeter diameter of the disc, similar results are achieved, i. it also results in a clear relationship between the rotation angle φ and the measurement signal.

The opposing first and second electrodes should be as flat as possible - with an intermediate dielectric. This can also be achieved by additional pressure with which the carriers for the respective electrodes are pressed against each other. This reduces the distance between the electrodes, resulting in a higher capacitance value. Overall, this results in even better signal quality and higher reproducibility.

The angle range can be at the in the 1 exemplified sensor can still be extended by the middle electrode 3 smaller and the outer electrodes 1 . 4 be chosen correspondingly larger. This in 9 indicated by way of example.

The 0 ° position at which the measurement starts or the measuring range begins is preferably automatically detected in the case of the proposed angle sensor. This can be realized by suitable electrical contacts or a defined mechanical end stop of the mechanical rotation. Thus, even with slowly changing values of the capacitances C ₁₃ and C _34, the correct angle value can be determined.

10 Finally, shows another example of the extension of the angle range. This will be on the same axis of rotation 5 another Angle sensor with three additional static electrodes 1a . 4a . 3a and a rotatable electrode 2a arranged, this second angle sensor is rotated relative to the first angle sensor by 120 °. This is in the 10 indicated. The second angle sensor is in the 10 only shown for better representation with a larger diameter. Of course, both angle sensors can also have the same diameter. The use of two angle sensors also requires two corresponding measuring circuits, but overall a larger angular range can be detected by this configuration.

11 shows a schematic representation of another arrangement in which two angle sensors with a common second electrode 2 on the same axis of rotation 5 are arranged. The first three electrodes 1a . 3a . 4a are in a first level, the second electrode 2 in a second level and the three other first electrodes 1b . 3b . 4b arranged in a third level. The planes are parallel to each other with the second plane between the first and third planes. The electrodes are again each on a suitable support with a flat surface. The two carriers with the total of six first electrodes are static, while the carrier with the second electrode 2 around the axis of rotation 5 is rotatably mounted. The first electrodes 1b . 3b . 4b the third level are congruent over the first electrodes 1a . 3b . 4b the first level so that they overlap exactly. The three statically arranged electrodes of the first and third levels are each connected to a measuring circuit, as has already been described in the preceding examples. However, the interconnection of the electrodes of the first and third levels is reversed, as can be seen by the reversal of the designations of the electrodes ( 1b and 4b exchanged with respect. 1a and 4a ) in the 11 is indicated. Thus, the two measuring circuits deliver upon rotation of the second electrode 2 an opposite signal. When the measured signal, for example the frequency or voltage amplitude, of one measuring circuit rises, the measuring signal of the other measuring circuit decreases and vice versa. By forming the difference between the two measurement signals, a common-mode suppression can be achieved and an overall larger measurement signal can be obtained than when using only one angle sensor.

LIST OF REFERENCE NUMBERS

1, 1a / b

 Outer first electrode

2, 2a

 Rotatable second electrode

3, 3a / b

 Middle first electrode

4, 4a / b

 Outer first electrode

5

 axis of rotation

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1033578 A2 [0005]

Claims (12)

Capacitive angle sensor comprising at least - three in a first plane about a rotation axis ( 5 ) statically arranged first electrodes ( 1 . 3 . 4 ), which is perpendicular to the first plane, and - one about the axis of rotation ( 5 ) rotatable second electrode ( 2 ) in a second to the first parallel plane with respect to the first electrodes ( 1 . 3 . 4 ) and at least two of the first electrodes ( 1 . 3 . 4 ) are each at least partially covered to form a capacitance, - wherein the second electrode ( 2 ) and the three first electrodes ( 1 . 3 . 4 ) are dimensioned and arranged such that the second electrode ( 2 ) in a rotation angle range a constant coverage with a middle ( 3 ) of the three first electrodes ( 1 . 3 . 4 ) and the overlap with the other two first electrodes ( 1 . 4 ) changes in rotation in this rotation angle range in opposite directions, and - wherein the three first electrodes ( 1 . 3 . 4 ) are electrically connected in a measuring circuit such that they have two circuit capacitances in the measuring circuit, in each case between the middle ( 3 ) and one of the other two first electrodes ( 1 . 4 ), and the measuring circuit is designed so that it provides a dependent of the two circuit capacitances frequency or electrical voltage amplitude or a difference or a ratio of two frequencies or electrical voltage amplitudes as a measure of the angle of rotation. Capacitive angle sensor according to claim 1, characterized in that the first electrodes ( 1 . 3 . 4 ) and the second electrode ( 2 ) each have the geometry of circle segments. Capacitive angle sensor according to claim 2, characterized in that the two other first electrodes ( 1 . 4 ) each form circle segments of ≥ 120 °. Capacitive angle sensor according to one of claims 1 to 3, characterized in that the measuring circuit for each of the two circuit capacitances comprises a multivibrator having a switching frequency influenced by the value of the respective circuit capacitance. Capacitive angle sensor according to one of claims 1 to 3, characterized in that the measuring circuit is designed as a multivibrator having a dependent on the value of the two circuit capacitance switching frequency, wherein one of the two circuit capacitances arranged in a feedback branch of the multivibrator and the measured variable is the output frequency of the multivibrator. Capacitive angle sensor according to one of claims 1 to 3, characterized in that the measuring circuit comprises two amplification branches for an AC voltage as an input voltage, wherein one of the two circuit capacitances is arranged in each of the amplification branches, and wherein the measuring circuit as a measured variable, a ratio and / or a difference the output voltage amplitudes of the two gain branches supplies. Capacitive angle sensor according to one of claims 1 to 6, characterized in that the distance between the first and the second plane is ≤ 50 microns. Capacitive angle sensor according to one of claims 1 to 7, characterized in that between the first electrodes ( 1 . 3 . 4 ) and the second electrode ( 2 ) a dielectric film or layer with a relative dielectric constant ε _r > 3 is arranged. Arrangement of at least two of the capacitive angle sensors according to one of Claims 1 to 8, which are mounted on the same axis of rotation ( 5 ) are arranged. Arrangement according to claim 9, characterized in that the two angle sensors a common second electrode ( 2 ), which around the axis of rotation ( 5 ) is rotatable. Arrangement according to claim 9 or 10, characterized in that the first electrodes ( 1 . 3 . 4 ) of the two angle sensors in the respective measuring circuit are electrically connected in such a way that the two angle sensors rotate when the second electrode (s) ( 2 ) about the axis of rotation ( 5 ) provide an opposite measurement signal. Arrangement according to claim 9, characterized in that the two angle sensors offset by an angle to each other on the axis of rotation ( 5 ) are arranged.

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