Rotation detector

Abstract

The present invention suppresses the occurrence of erroneous detection by a rotation detector. A rotation detector (1) is provided with: a magnet (10) that rotates around a predetermined axis; a power generation circuit (50) having a power generation element (20) that generates power using the large Barkhausen effect, a voltage detection unit (31) that detects the voltage generated by the power generation element (20), and a power storage unit (32) that stores power generated by the power generation element (20); a rotation position detection unit (60) having a magnetic sensor (61) provided corresponding to the power generation element (20) and an information processing unit (62) for determining the rotation position of the rotation shaft; a power supply unit (70) that supplies power generated by the power generation element (20) to the magnetic sensor (61); and a control circuit (80). The control circuit (80) controls the supply of power generated by the power generation element (20) from the power supply unit (70) to the magnetic sensor (61) on the basis of the voltage generated by the power generation element (20), the first voltage threshold value, and the second voltage threshold value.

Description

Technical Field

[0001] This disclosure relates to a rotating detector. Background Technology

[0002] Conventionally, rotation detectors are known for detecting the rotation of a motor's rotating shaft. Furthermore, rotation detectors are known that perform rotation detection in the absence of power supply from a battery or external power source, using power supplied from a power generation circuit that generates electricity based on changes in the magnetic field caused by a magnet mounted on the rotating shaft (e.g., Patent Document 1).

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6610697 Summary of the Invention

[0006] However, in a rotary detector that performs rotation detection by power supplied from a power generation circuit, such as the rotary detector disclosed in Patent Document 1, there is a problem that false detection may occur if the voltage generated by the power generation circuit does not reach the operating voltage of the rotary detector. This is because the power generated by the power generation circuit cannot be properly supplied to the circuit that performs rotation detection.

[0007] This disclosure was made to solve such a problem and aims to provide a rotating detector capable of suppressing false detections.

[0008] One aspect of this disclosure relates to a rotation detector comprising a magnet, a first power generation circuit, a first rotational position detection unit, and a power supply unit. The magnet rotates about a given axis. The first power generation circuit comprises a first power generation element, a voltage detection unit, and a storage unit. The first power generation element generates electricity using the large Backhausen effect, which is produced by the change in the magnetic field caused by the rotation of the magnet about the given axis. The voltage detection unit detects the voltage generated by the first power generation element. The storage unit stores the first electrical energy generated by the first power generation element. The first rotational position detection unit comprises a first magnetic sensor and a first information processing unit. The first magnetic sensor detects the magnetic field generated by the magnet and is positioned corresponding to the first power generation element. The first information processing unit determines the rotational position of the rotational axis based on the detection result of the first magnetic sensor. The power supply unit supplies the first electrical energy to the first magnetic sensor. The control circuit controls the supply of the first electrical energy by the power supply unit. Furthermore, the control circuit controls the supply of the first power from the power supply unit to the first magnetic sensor based on the voltage generated by the first power generation element, a first voltage threshold for detecting the voltage, and a second voltage threshold for detecting the voltage that is greater than the first voltage threshold.

[0009] According to this disclosure, a rotating detector capable of suppressing false detections can be provided. Attached Figure Description

[0010] Figure 1 This is a cross-sectional view showing the schematic structure of the rotating detector involved in the embodiment.

[0011] Figure 2 This is a top view of the substrate in the rotary detector according to the embodiment.

[0012] Figure 3 This is a top view of the rotating plate in the rotating detector according to the embodiment.

[0013] Figure 4 This is a diagram illustrating the circuit structure of the rotation detector according to the embodiment.

[0014] Figure 5 This is a timing diagram illustrating a specific example of the operation of the rotating detector according to the embodiment.

[0015] Figure 6 This is a graph used to illustrate the relationship between the voltage generated by the power generation element and the voltage threshold in the implementation method.

[0016] Figure 7 This is another diagram used to illustrate the relationship between the voltage generated by the power generation element in the embodiment and the voltage threshold.

[0017] Figure 8 This is a diagram illustrating an example of the waveform of the voltage obtained by the power generation of the power generation element according to the embodiment.

[0018] Figure 9 This diagram illustrates the case where the voltage detection unit involved in the embodiment has three or more voltage thresholds.

[0019] Figure 10 This is another diagram used to illustrate the case where the voltage detection unit involved in the embodiment has three or more voltage thresholds.

[0020] Figure 11 This is a diagram illustrating the circuit structure of a rotation detector involved in a variation of the embodiment.

[0021] Figure 12 This is a diagram illustrating the relationship between the capacity and voltage waveforms of the energy storage unit in a modified embodiment. Detailed Implementation

[0022] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Furthermore, each of the embodiments described below illustrates a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, and connection methods shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Consequently, constituent elements in the following embodiments not described in the independent claims of the present disclosure will be described as arbitrary constituent elements.

[0023] Furthermore, these figures are schematic diagrams and may not be strictly accurate representations. Therefore, the scales and other parameters may not be consistent across different figures. Additionally, substantially identical structures are labeled with the same reference numerals across different figures, and repetitive descriptions are omitted or simplified.

[0024] Furthermore, in this specification, terms such as orthogonal and parallel indicating the relationship between elements, terms such as rectangle indicating the shape of elements, and numerical ranges are not merely expressions with a strict meaning, but rather expressions that imply substantially equal ranges, for example, including differences of a few percent.

[0025] Furthermore, in the following description of the rotary detector involved in this disclosure, "up" and "down" do not refer to the absolute spatial direction of upward (vertical) and downward (vertical) but rather to directions defined by relative positional relationships, and do not limit the posture of the rotary detector involved in this disclosure during manufacturing or use.

[0026] (Implementation Method)

[0027] The rotation detector described in this embodiment will now be explained.

[0028] [structure]

[0029] First, the structure of the rotating detector involved in this embodiment will be described. Figure 1 This is a cross-sectional view showing the schematic structure of the rotary detector 1 according to this embodiment. Figure 2 This is a top view of the substrate 17 in the rotation detector 1 according to this embodiment. Figure 3 This is a top view of the rotating plate 15 in the rotating detector 1 according to this embodiment. Figure 4 This is a diagram showing the circuit structure of the rotation detector 1 according to this embodiment. Additionally, in Figure 1 In the diagram, the magnetic component 21 and the coil 22 housed within the casing 23 of the power generation element 20 are schematically shown with dashed lines. Furthermore, in... Figure 2 In the diagram, the outlines of the magnet 10, the rotation shaft 16, and the magnetic sensor 61, which are disposed on the lower side of the substrate 17, are shown with dashed lines. Furthermore, in... Figure 3 In the diagram, the outline of the rotation shaft 16, located on the lower side of the rotating plate 15, is shown with dashed lines. Furthermore, in... Figure 4 In the diagram, some of the constituent elements are shown using functional blocks.

[0030] like Figures 1 to 4 As shown, the rotation detector 1 includes a magnet 10, a rotating plate 15, a substrate 17, multiple power generation circuits 50, multiple rotation position detection units 60, a power supply unit 70, a control circuit 80, multiple reverse current prevention circuits 81a and 81b, and an oscillator (OSC) 90. Each of the multiple power generation circuits 50 includes a power generation element 20, a voltage detection unit 31, a power storage unit 32, a rectifier 33, and a discharge unit 34. Each of the multiple rotation position detection units 60 includes a magnetic sensor 61 and an information processing unit 62.

[0031] The rotation detector 1 is used, for example, in combination with a motor such as a servo motor. The rotation detector 1 is disposed at one end of the rotation axis 16 of the motor, etc. The rotation axis direction is the direction in which the rotation axis A of the rotation axis 16 extends. The rotation axis 16 rotates about a given rotation axis A. The rotation detector 1 detects, for example, the rotational position of the rotation axis 16. The rotation detector 1 can also detect the rotation direction of the rotation axis 16, and can also detect the number of rotations of the rotation axis 16. The shape of the rotation axis 16 is a cylindrical or rod-like shape extending in the rotation axis direction. The axis of the rotation axis 16 coincides with the rotation axis A. Furthermore, the rotation axis 16 is not limited to the shaft of a motor; it can also be the rotation axis of a rotating body connected to the shaft of a motor via gears or the like. Moreover, the rotation axis 16 is not limited to the rotation axis of a motor; it can also be the rotation axis of a rotating mechanism that rotates around an axis, such as the axle of a wheel in a car or tram.

[0032] First, refer to Figure 1 , Figure 2 as well as Figure 3The construction of the rotation detector 1 will be explained.

[0033] The rotating plate 15 is a plate-shaped component that rotates together with the rotating shaft 16. The central portion of one main surface of the rotating plate 15 is mounted to the end of the rotating shaft 16 in the direction of its rotation axis (the direction in which the rotating shaft 16 extends). The rotating plate 15 extends in a direction orthogonal to the rotation axis of the rotating shaft 16. The rotating plate 15 rotates about a rotation axis A that passes through the center of the rotating shaft 16 and extends along the axial direction of the rotating shaft 16. The top view of the rotating plate 15 is, for example, circular. The rotating plate 15 is made of, for example, metal, resin, glass, or ceramic.

[0034] Magnet 10 applies a magnetic field to power generation element 20 and magnetic sensor 61. Magnet 10 is, for example, a plate-shaped magnet. Magnet 10 is positioned opposite rotating plate 15 and substrate 17 on the main surface of rotating plate 15 opposite to the side of rotation axis 16. The thickness direction of rotating plate 15 and magnet 10 is the same, which is the direction of the rotation axis of rotation of rotating shaft 16. Magnet 10 is fixed to rotating shaft 16 via rotating plate 15 and rotates together with rotating plate 15 about the rotation axis A of rotating shaft 16 as the center of rotation. Magnet 10 can also be fixed to rotating shaft 16 by a component other than rotating plate 15. The rotation direction of magnet 10 is, for example, both clockwise and counterclockwise, but it can also be either clockwise or counterclockwise. In addition, the rotation direction of magnet 10 is along the circumference centered on rotation axis A. The top view shape of magnet 10 is a circular shape with an opening in the center, but it can also be another shape such as a rectangle. In addition, magnet 10 may not have an opening. Furthermore, the magnet 10 can be any shape, such as a rod-shaped magnet, as long as it can change the magnetic field applied to the power generation element 20 and the magnetic sensor 61. Additionally, there can be multiple magnets 10.

[0035] The magnet 10 has multiple pairs of magnetic poles magnetized in the thickness direction, and these multiple pairs of magnetic poles are arranged in the rotation direction of the magnet 10. Figure 3 The diagram shows the magnetic poles on the surface of the magnet 10, specifically the main surface 11, on the side of the power generation element 20. Each pair of magnetic poles is magnetized such that, for adjacent pairs of magnetic poles in the rotation direction of the magnet 10, the N and S poles are reversed. Furthermore, the direction of magnetization of the magnet 10 is not particularly limited; for example, it can be magnetized in a direction parallel to the rotating plate 15. Additionally, in... Figure 3 In the image, a dot pattern is applied to the N pole, but this is for ease of observation and does not mean that a dot pattern is actually applied.

[0036] In magnet 10, multiple magnetic poles are arranged along the rotation direction on the main surface 11 of magnet 10 on the side of power generation element 20. The multiple magnetic poles include at least one N pole and at least one S pole, which are arranged alternately along the rotation direction. In the multiple magnetic poles of magnet 10, the number of N poles is the same as the number of S poles.

[0037] Multiple magnetic poles are arranged such that the N pole and S pole sandwich the rotation axis A of rotation shaft 16. That is, the N pole sandwiching rotation axis A is opposed to the S pole, and the S pole sandwiching rotation axis A is opposed to the N pole. Figure 3 In the example shown, there are two magnetic poles, including one N pole and one S pole. Among the multiple magnetic poles, in the direction of rotation of magnet 10, the S pole is located 180 degrees offset from the N pole, and the N pole is located 180 degrees offset from the S pole. Viewed from the axis of rotation of rotation axis 16, all the magnetic poles are of equal size. By rotating magnet 10, a change in the magnetic field is applied to the power generation element 20 and the magnetic sensor 61. Furthermore, the position of each magnetic pole corresponds to the rotational position of rotation axis 16. The number of magnetic poles is not particularly limited; it can be four or more.

[0038] The substrate 17 is positioned opposite the rotating plate 15 and the magnet 10 on the magnet 10 side of the rotating plate 15, with a gap between them. That is, the rotating shaft 16, rotating plate 15, magnet 10, and substrate 17 are arranged sequentially along the rotation axis of the rotating shaft 16. The substrate 17 does not rotate with the magnet 10 and rotating plate 15. The substrate 17 is plate-shaped with its thickness along the rotation axis of the rotating shaft 16. The top view of the substrate 17 is, for example, circular. For example, when viewed from the rotation axis of the rotating shaft 16, the centers of the rotating shaft 16, rotating plate 15, and substrate 17 are aligned at the position of the rotation axis A. The substrate 17 is, for example, fixed to a housing (not shown) that constitutes part of the rotation detector 1 or a motor, etc.

[0039] The substrate 17 is, for example, a wiring substrate, on which electronic components such as a power generation element 20 and a magnetic sensor 61 are mounted. Figure 1 as well as Figure 2 In the example shown, a magnetic sensor 61 is mounted on the main surface of the substrate 17 on the side of the magnet 10, and a power generation element 20 is mounted on the main surface of the substrate 17 opposite to the magnet 10. Additionally, Figure 1 The illustration is omitted, but Figure 4 Other components in the rotary detector 1 shown, besides the magnet 10, can also be provided on the substrate 17.

[0040] The power generation element 20 generates electricity by changing the magnetic field formed by the magnet 10 due to the rotation of the magnet 10, specifically by reversing the orientation of the magnetic field, and outputs the electricity obtained from the power generation process. The power generation element 20 generates electricity by utilizing the large Backhausen effect generated by the change in the magnetic field caused by the rotation of the magnet 10 together with the rotating shaft 16.

[0041] The power generation element 20 is located on the main surface of the substrate 17 opposite to the magnet 10 side. The power generation element 20 is arranged side by side with the magnet 10 and the rotating plate 15 along the rotation axis of the rotation axis 16. The power generation element 20 does not rotate with the magnet 10 and the rotating plate 15. Alternatively, the power generation element 20 may also be located on the main surface of the substrate 17 on the magnet 10 side.

[0042] The power generation element 20 is positioned opposite the magnet 10 and the rotating plate 15 in the direction of the rotation axis of the rotation shaft 16. When viewed from the direction of the rotation axis of the rotation shaft 16, the power generation element 20 does not overlap with the rotation axis A, but is positioned offset from the rotation axis A. When viewed from the direction of the rotation axis of the rotation shaft 16, the power generation element 20 overlaps with the position through which the magnet 10 rotates. Furthermore, the power generation element 20 extends along the main surface of the substrate 17, extending tangentially in the rotation direction of the magnet 10. The longitudinal direction of the magnetic member 21 in the power generation element 20 and the winding axis direction of the coil 22 are the directions in which the power generation element 20 extends. Alternatively, the power generation element 20 may extend radially along a circle centered on the rotation axis A.

[0043] The power generation element 20 has, for example, a magnetic component 21, a coil 22 wound around the magnetic component 21, a housing 23, and terminals 24 and 25.

[0044] The magnetic component 21 is a magnetic material that produces the large Backhausen effect. The magnetic component 21 is, for example, a linear component extending tangentially to the rotational direction of the magnet 10. A specific example of the magnetic component 21 is a Wiegand wire. A Wiegand wire is a magnetic material whose magnetization direction becomes uniform and oriented towards the length direction when a magnetic field of a given value or higher is applied along its length. Specifically, the Wiegand wire includes a soft magnetic portion and a hard magnetic portion extending along its length. If the direction of the magnetic flux flowing along the length of the Wiegand wire changes, the magnetization direction of the soft magnetic portion of the Wiegand wire abruptly reverses, inducing a pulse-like voltage (voltage pulse) at both ends of the coil 22 wound around the Wiegand wire. In this way, the power generation element 20 generates electricity, outputting a voltage higher than that of ordinary induction power generation. Furthermore, the magnetic component 21 is not particularly limited to any magnetic material that produces the large Backhausen effect; it can also be a magnetic material other than a Wiegand wire.

[0045] The housing 23 houses and supports the magnetic component 21 and the coil 22. The magnetic component 21 and the coil 22 are, for example, embedded in resin or the like within the housing 23. Furthermore, the housing 23 houses a portion of the terminals 24 and 25. The housing 23 has, for example, an opening on the magnet 10 side of the power generation element 20. The housing 23 is fixed to the substrate 17, for example, by a fixing member (omitted from the illustration). Additionally, although not shown, soft magnetic components such as ferrite beads disposed at both ends of the magnetic component 21 can also be housed in the housing 23.

[0046] Terminals 24 and 25 are components used to electrically connect the power generation element 20 and the substrate 17. Terminals 24 and 25 are located at the ends of the power generation element 20 on the substrate 17 side. A magnet 10 is disposed on the side of terminals 24 and 25 in the power generation element 20. Terminal 24 is electrically connected to one end of the wire constituting the coil 22, and terminal 25 is electrically connected to the other end of the wire. That is, the coil 22 and the substrate 17 are electrically connected via terminals 24 and 25.

[0047] The magnetic sensor 61 detects the magnetic field generated by the magnet 10. The magnetic sensor 61 is, for example, a magnetoresistive (TMR) sensor or a Hall element sensor.

[0048] The magnetic sensor 61 is located on the main surface of the substrate 17 on the side of the magnet 10. The magnetic sensor 61 is arranged side by side with the magnet 10 and the rotating plate 15 along the rotation axis of the rotation shaft 16. The magnetic sensor 61 does not rotate with the magnet 10 and the rotating plate 15. Alternatively, the magnetic sensor 61 may also be located on the main surface of the substrate 17 on the side opposite to the magnet 10 side.

[0049] The magnetic sensor 61 is positioned opposite the magnet 10 and the rotating plate 15 along the rotation axis of the rotation shaft 16. When viewed from the rotation axis of the rotation shaft 16, the magnetic sensor 61 does not overlap with the rotation axis A, but is positioned offset from it. When viewed from the rotation axis of the rotation shaft 16, the magnetic sensor 61 overlaps with the position traversed by the magnet 10 during rotation.

[0050] In this embodiment, the rotation detector 1 includes multiple power generation circuits 50 and multiple rotation position detection units 60, therefore multiple power generation elements 20 and magnetic sensors 61 are also provided. Figures 1 to 4In the example shown, there are two power generation circuits 50 and two rotational position detection units 60, but there could also be one or more. Furthermore, to distinguish between multiple power generation circuits 50, the power generation circuits 50 and the power generation elements 20 included in the power generation circuits 50 are sometimes referred to as power generation circuits 50a and 50b and power generation elements 20a and 20b. Power generation circuit 50a is an example of a first power generation circuit, and power generation circuit 50b is an example of a second power generation circuit connected in parallel with the first power generation circuit. Furthermore, power generation element 20a is an example of a first power generation element, and power generation element 20b is an example of a second power generation element. Additionally, to distinguish between multiple rotational position detection units 60, the rotational position detection units 60 and the magnetic sensors 61 included in the rotational position detection units 60 are sometimes referred to as rotational position detection units 60a and 60b and magnetic sensors 61a and 61b. Rotational position detection unit 60a is an example of a first rotational position detection unit, and rotational position detection unit 60b is an example of a second rotational position detection unit. Furthermore, magnetic sensor 61a is an example of a first magnetic sensor, and magnetic sensor 61b is an example of a second magnetic sensor.

[0051] Multiple magnetic sensors 61 are respectively provided corresponding to multiple power generation elements 20. Specifically, magnetic sensor 61a is provided corresponding to power generation element 20a and operates based on the electricity generated by power generation element 20a. Furthermore, magnetic sensor 61b is provided corresponding to power generation element 20b and operates based on the electricity generated by power generation element 20b. The electricity generated by power generation element 20a is an example of a first type of electricity, and the electricity generated by power generation element 20b is an example of a second type of electricity.

[0052] Multiple power generation elements 20 are arranged along the rotation direction of the magnet 10, with adjacent power generation elements 20 configured to form a given angle centered on the rotation axis A. Similarly, multiple magnetic sensors 61 are also arranged along the rotation direction of the magnet 10, with adjacent magnetic sensors 61 configured to form a given angle centered on the rotation axis A. The given angle is not particularly limited. Furthermore, the correspondingly arranged power generation elements 20 and magnetic sensors 61, when viewed from the rotation axis direction of the rotation shaft 16, are radially aligned along a circle centered on the rotation axis A. Figure 2 The direction of the extension of the single-dot dashed line in the image. Figure 2In the example shown, a magnetic sensor 61 is disposed on the outside of the power generation element 20. Alternatively, the magnetic sensor 61 may be disposed between the power generation element 20 and the rotation axis A, or the rotation axis A may be disposed between the magnetic sensor 61 and the power generation element 20. Furthermore, the power generation element 20 and the magnetic sensor 61 may be arranged along the rotation direction of the magnet 10 when viewed from the rotation axis direction of the rotation axis 16.

[0053] Next, refer to Figure 4 This section will explain the details of the functional structure of the rotating detector 1.

[0054] Multiple power generation circuits 50 have the same functional structure, each including a power generation element 20, a voltage detection unit 31, an energy storage unit 32, a rectifier 33, and a discharge unit 34. The multiple power generation circuits 50 are connected in parallel. The power generation circuits 50 supply the power generated by the power generation element 20 to the power supply unit 70.

[0055] As described above, the power generation element 20 generates electricity based on the change in the magnetic field caused by the rotation of the magnet 10.

[0056] The voltage detection unit 31 detects the voltage generated by the power generation element 20. Specifically, the voltage detection unit 31 is located between the rectifier 33 and the energy storage unit 32, detecting the voltage generated by the power generation element 20. Figure 4 As shown, the voltage detected by the voltage detection unit 31 is either voltage VWC1 or voltage VWC2, which corresponds to the power stored in the energy storage unit 32. Hereinafter, without distinguishing between the power generation circuit 50a and the power generation circuit 50b to explain the content applicable to both, voltage VWC1 and voltage VWC2 will sometimes be referred to simply as "voltage VWC".

[0057] The voltage detection unit 31 has multiple voltage thresholds for detecting the voltage VWC generated by the power generation element 20. Details of these voltage thresholds will be described later, but the voltage detection unit 31 has at least a first voltage threshold and a second voltage threshold greater than the first voltage threshold as multiple voltage thresholds. The voltage detection unit 31 is, for example, configured with comparators corresponding to each voltage threshold. That is, in this example, having voltage thresholds means having comparators that compare the voltage VWC with the voltage thresholds. The voltage detection unit 31 outputs the voltage detection result to the control circuit 80. For example, when the voltage VWC input to the comparator exceeds a voltage threshold, the voltage detection unit 31 outputs a signal indicating that the voltage threshold has been exceeded.

[0058] The energy storage unit 32 stores the electricity (in other words, charge) generated by the power generation element 20. The energy storage unit 32 is composed of a capacitor element. One end of the energy storage unit 32 is connected to the output of the rectifier 33, and the other end of the energy storage unit 32 is connected to ground.

[0059] The rectifier 33 is connected to the power generation element 20 to perform full-wave rectification of the current generated by the power generation element 20. The current rectified by the rectifier 33 is used to store electricity in the energy storage unit 32.

[0060] The discharge section 34 discharges the power stored in the energy storage section 32. The discharge section 34 is, for example, a switch that discharges the power stored in the energy storage section 32 by short-circuiting the energy storage section 32 to ground.

[0061] Multiple rotational position detection units 60 have the same functional structure as each other, and each has a magnetic sensor 61 and an information processing unit 62.

[0062] As described above, the magnetic sensor 61 detects the magnetic field generated by the magnet 10.

[0063] The information processing unit 62 is a processing circuit that performs rotational position detection processing. The information processing unit 62 of the rotational position detection unit 60a is an example of a first information processing unit, and the information processing unit 62 of the rotational position detection unit 60b is an example of a second information processing unit. The information processing unit 62 determines the rotational position of the rotating shaft 16 based on the detection result of the magnetic sensor 61. The information processing unit 62 is implemented, for example, using a memory and a processor. The information processing unit 62 can also be implemented using a dedicated logic circuit for rotational position detection processing. For example, the information processing unit 62 determines the polarity of the magnet 10 that applies a magnetic field to the magnetic sensor 61, and stores the determination result as rotational position information in the memory. Furthermore, multiple rotational position detection units 60 can share the information processing unit 62.

[0064] The power supply unit 70 supplies power generated by the power generation element 20 to the rotary position detection unit 60. The power supply unit 70 supplies power to at least the magnetic sensor 61. The power supply unit 70 may also supply power to the information processing unit 62. The power supply unit 70 is connected to the energy storage unit 32 of the power generation circuit 50a via a reverse current prevention circuit 81a, and to the energy storage unit 32 of the power generation circuit 50b via a reverse current prevention circuit 81b. The power supply unit 70 uses the ground potential as a reference potential and the voltage between the terminals of the capacitor element in the energy storage unit 32 as an input voltage, outputting a certain voltage VLDO. The voltage VLDO output from the power supply unit 70 is supplied, for example, to the magnetic sensor 61 of the rotary position detection unit 60 and the information processing unit 62. The power supply unit 70 is, for example, an LDO (Low Drop Out) regulator.

[0065] The control circuit 80 is a processing circuit that controls the operation of the rotation detector 1. Based on the voltage VWC generated by the power generation element 20, a first voltage threshold, and a second voltage threshold, the control circuit 80 controls the supply of electricity generated by the power generation element 20 from the power supply unit 70 to the magnetic sensor 61. For example, based on the voltage VWC generated by the power generation element 20, the first voltage threshold, and the second voltage threshold, the control circuit 80 controls whether the discharge unit 34 discharges the electricity stored in the energy storage unit 32, thereby controlling the supply of electricity generated by the power generation element 20 from the power supply unit 70 to the magnetic sensor 61. Furthermore, for example, based on the detection result of the voltage VWC by the voltage detection unit 31, the control circuit 80 determines whether to supply the electricity generated by the power generation element 20 to the magnetic sensor 61 via the power supply unit 70, according to the detection result based on the first voltage threshold and the detection result based on the second voltage threshold in the voltage detection unit 31.

[0066] Furthermore, the control circuit 80 can also control the switching on and off of multiple reverse current prevention circuits 81a and 81b based on the voltage detection results from the voltage detection units 31 of each of the multiple power generation circuits 50. Controlling the switching on and off of the multiple reverse current prevention circuits 81a and 81b means controlling whether the reverse current prevention function of the multiple reverse current prevention circuits 81a and 81b, as detailed later, is activated. The reverse current prevention function is activated when the circuit is on, and deactivated when the circuit is off. Furthermore, by controlling the switching on and off of the multiple reverse current prevention circuits 81a and 81b, the control circuit 80 can also control whether the power generated by the power generation element 20a of the power generation circuit 50a is supplied to the magnetic sensor 61a of the rotational position detection unit 60a via the power supply unit 70, or whether the power generated by the power generation element 20b of the power generation circuit 50b is supplied to the magnetic sensor 61b of the rotational position detection unit 60b.

[0067] The control circuit 80 is implemented, for example, by a memory and a processor. The control circuit 80 can also be implemented by dedicated logic circuitry that performs the processes described above and later. Furthermore, although in Figure 4 Although not shown in the figure, a voltage VWC can also be supplied to the control circuit 80.

[0068] Multiple reverse current prevention circuits 81a and 81b are provided corresponding to multiple power generation circuits 50. Reverse current prevention circuit 81a is provided between power generation circuit 50a and power supply unit 70. Reverse current prevention circuit 81b is provided between power generation circuit 50b and power supply unit 70. Furthermore, each of the multiple reverse current prevention circuits 81a and 81b is located on the connection path between energy storage unit 32 and power supply unit 70. Specifically, reverse current prevention circuit 81a is provided corresponding to power generation circuit 50a and has a reverse current prevention function to prevent the supply of power obtained from power generation by power generation element 20b from power generation circuit 50b to power generation circuit 50a. Similarly, reverse current prevention circuit 81b is provided corresponding to power generation circuit 50b and has a reverse current prevention function to prevent the supply of power obtained from power generation by power generation element 20a from power generation circuit 50a to power generation circuit 50b. Each of the multiple reverse current prevention circuits 81a and 81b includes, for example, a switch that is controlled to be turned on and off by control circuit 80. In this case, the reverse current prevention circuit 81a switches the conduction and non-conduction of the power generation circuit 50a, the power supply unit 70, and the power generation circuit 50b, while the reverse current prevention circuit 81b switches the conduction and non-conduction of the power generation circuit 50b, the power supply unit 70, and the power generation circuit 50a. In the following description, unless specifically mentioned, the case where multiple reverse current prevention circuits 81a and 81b are configured to be independently switched will be described. That is, the case where the reverse current prevention function based on multiple reverse current prevention circuits 81a and 81b is variable will be described. Furthermore, each of the multiple reverse current prevention circuits 81a and 81b can also be composed of a diode. In this case, the cathode of the diode is connected to the power supply unit 70, and the anode of the diode is connected to the energy storage unit 32.

[0069] The oscillator 90 supplies an operating clock to the information processing unit 62 and the control circuit 80. Voltages VWC1 and VWC2, generated from electricity produced by the power generation element 20, are supplied to the oscillator 90. The oscillator 90 includes, for example, an oscillation circuit capable of switching between voltages VWC1 and VWC2. The higher of voltages VWC1 and VWC2 is applied to this oscillation circuit.

[0070] In addition, the rotation detector 1 may also have an input interface (not shown) that accepts input from the user.

[0071] [action]

[0072] Next, an example of the operation of the rotation detector 1 according to this embodiment will be described.

[0073] Figure 5 This is a timing diagram illustrating a specific example of the operation of the rotating detector 1 according to this embodiment. Figure 5The diagram shows an example of timing the operation when the power generation element 20a of the power generation circuit 50a is normally generating electricity. Hereinafter, an example of the operation of the rotational position detection unit 60a when it uses the electricity generated by the power generation element 20a of the power generation circuit 50a to perform rotational position detection processing will be described. Therefore, in the following description, unless specifically mentioned, the rotational position detection processing associated with the power generation circuit 50a and the rotational position detection unit 60a will be explained.

[0074] exist Figure 5 The “VWC” section shows the change in voltage VWC1 in the power generation circuit 50a. Figure 5 In the “OSC” diagram, the output of oscillator 90 is schematically shown. Specifically, the period during which oscillator 90 outputs a clock signal until the clock stabilizes is shown as a rectangle with a diagonal line pattern, and the period during which oscillator 90 outputs a stable clock signal is shown as a rectangle with a vertical line pattern. Figure 5 The “first voltage threshold” shows the output of the voltage detection unit 31 based on the first voltage threshold V1. If the voltage VWC1 exceeds the first voltage threshold V1, the output changes from low to high. Figure 5 The “second voltage threshold” shows the output of the voltage detection unit 31 based on the second voltage threshold V2. If the voltage VWC1 exceeds the second voltage threshold V2, the output changes from low to high. Figure 5 The "backflow prevention circuit" shows control signals used to control backflow prevention circuits 81a and 81b. When the control signal is low, backflow prevention circuits 81a and 81b are activated, and their backflow prevention function is displayed. When the control signal is high, backflow prevention circuits 81a and 81b are deactivated, and their backflow prevention function is not displayed. Figure 5 In the example shown, the reverse current prevention circuit 81b is always on during the illustrated period, thus preventing the power generated by the power generation element 20a from being supplied from the power generation circuit 50a to the power generation circuit 50b.

[0075] The following is for reference Figure 5 This will explain the operation of the rotating detector 1.

[0076] First, in each circuit of the rotation detector 1 (in Figure 4 In the example shown, with the control circuit 80, reverse current prevention circuits 81a and 81b, information processing unit 62, and voltage detection unit 31) reset, if the rotating shaft 16 rotates, the magnetic field from the magnet 10 applied to the power generation element 20a changes, thereby causing the power generation element 20a to generate electricity, and the voltage VWC1 begins to rise. Figure 5In the example shown, at time t1, the voltage VWC1 reaches the first voltage threshold V1. Therefore, the voltage detection unit 31 outputs the detection result based on the first voltage threshold V1 to the control circuit 80, and the control circuit 80 acquires the output detection result based on the first voltage threshold V1. Furthermore, the control circuit 80 starts time measurement triggered by the acquisition of the detection result based on the first voltage threshold V1. The first voltage threshold V1 is, for example, set to a voltage above that required to stabilize the clock output by the oscillator 90. When the voltage VWC1 reaches the first voltage threshold V1, the clock output by the oscillator 90 stabilizes. That is, the internal clock in the rotation detector 1 is initialized.

[0077] Furthermore, if the control circuit 80 obtains a detection result based on the first voltage threshold V1, it sets the reverse current prevention circuit 81a to off, thereby turning on the power generation circuit 50a and the power supply unit 70.

[0078] Next, the control circuit 80 determines whether to supply the power generated by the power generation element 20a to the magnetic sensor 61a based on whether the detection result of voltage VWC1 by the voltage detection unit 31 meets a given determination criterion. For example, the control circuit 80 measures the time Δt from when voltage VWC1 reaches the first voltage threshold V1 to when it reaches the second voltage threshold V2 in the voltage detection unit 31, and determines whether the measured time Δt is below a given value. Figure 5 In the example shown, at time t2, the voltage VWC1 reaches the second voltage threshold V2. Therefore, the voltage detection unit 31 outputs the detection result based on the second voltage threshold V2 to the control circuit 80, and the control circuit 80 acquires the output detection result based on the second voltage threshold V2. The control circuit 80 measures the time Δt from time t1 to time t2. The second voltage threshold V2 is, for example, set to a voltage higher than the voltage required to supply the power for the rotational position detection processing performed by the rotational position detection unit 60a. By having the voltage VWC1 exceed the second voltage threshold V2, the occurrence of false detection of rotational position by the rotational position detection unit 60a can be suppressed.

[0079] When the control circuit 80 determines that the voltage VWC1 detected by the voltage detection unit 31 meets a given determination criterion, it supplies the power generated by the power generation element 20a to the magnetic sensor 61a via the power supply unit 70. The control circuit 80 does not discharge the power stored in the energy storage unit 32 via the discharge unit 34, and keeps the reverse current prevention circuit 81a in the off state, thereby supplying the power generated by the power generation element 20a to the magnetic sensor 61a via the power supply unit 70. Thus, the control circuit 80 controls the power supply from the power supply unit 70 to the magnetic sensor 61a.

[0080] Next, the information processing unit 62 determines the rotational position of the rotating shaft 16 based on the detection result of the magnetic sensor 61a. For example, based on the detection result of the magnetic sensor 61a, the information processing unit 62 determines the polarity of the magnet 10 that applies a magnetic field to the magnetic sensor 61a, and stores the determined result as rotational position information representing the rotational position of the rotating shaft 16 in the memory.

[0081] Next, the control circuit 80 activates the reverse current prevention circuit 81a and deactivates the power generation circuit 50a and the power supply unit 70. Then, the control circuit 80 discharges the power stored in the energy storage unit 32 via the discharge unit 34, performing a discharge process. As a result, the voltage VWC1 decreases, returning to the state before power generation based on the power generation element 20a. In other words, the circuits of the rotation detector 1 are reset. Figure 5 In the example shown, the reverse current prevention circuit 81a is turned on at time t3, and the discharge process begins at time t4. Furthermore, there is no particular restriction on the sequence of actions from time t3 to time t4.

[0082] On the other hand, if the control circuit 80 determines that the voltage detection result of the voltage VWC1 by the voltage detection unit 31 does not meet the given determination criteria, it turns on the reverse current prevention circuit 81a and turns off the power generation circuit 50a and the power supply unit 70. At this time, even if the voltage VWC1 does not reach the second voltage threshold V2 after a given time from time t1, the control circuit 80 determines that the given determination criteria are not met because the time Δt exceeds a given value. Then, the control circuit 80 discharges the power stored in the energy storage unit 32 through the discharge unit 34, performing a discharge process. Thus, the control circuit 80 controls the power supply from the power supply unit 70 to the magnetic sensor 61a. The control circuit 80 prevents the power generated by the power generation element 20a from being supplied from the power supply unit 70 to the magnetic sensor 61a, and the information processing unit 62 does not perform rotational position detection processing. Therefore, false detection of the rotational position of the rotating shaft 16 due to insufficient power supplied to the magnetic sensor 61a does not occur.

[0083] Furthermore, the above actions are repeated by rotating the rotating axis 16.

[0084] Furthermore, in the example of the operation described above, when the voltage VWC1 reaches the first voltage threshold V1, the clock output by the oscillator 90 stabilizes, and the internal clock in the rotation detector 1 is initialized. However, the oscillator 90 can also be triggered to output a clock when the voltage VWC1 exceeds the first voltage threshold V1. For example, the oscillator 90 may have an enable terminal, and the voltage detection unit 31 may output an enable signal to the enable terminal of the oscillator 90 when the voltage VWC1 reaches the first voltage threshold V1. In other words, the voltage detection unit 31 may also output a trigger signal that initializes the internal clock of the rotation detector 1 when the voltage VWC1 reaches the first voltage threshold V1.

[0085] Furthermore, in the above-described example of operation, the operation of the rotational position detection unit 60a using power generated by the power generation element 20a of the power generation circuit 50a for rotational position detection processing was explained. However, the same operation is performed when the rotational position detection unit 60b uses power generated by the power generation element 20b of the power generation circuit 50b for rotational position detection processing. That is, the operation is explained by replacing the power generation circuit 50a, power generation element 20a, rotational position detection unit 60a, magnetic sensor 61a, reverse current prevention circuit 81a, and voltage VWC1 with the power generation circuit 50b, power generation element 20b, rotational position detection unit 60b, magnetic sensor 61b, reverse current prevention circuit 81b, and voltage VWC2, respectively. Furthermore, since the multiple power generation elements 20 are arranged along the rotation direction of the magnet 10, voltage VWC1 and voltage VWC2 typically do not rise simultaneously.

[0086] Furthermore, the control circuit 80 controls the reverse current prevention circuit 81a and the reverse current prevention circuit 81b to not be turned off simultaneously. For example, after turning off the reverse current prevention circuit 81a, the control circuit 80 does not turn off the reverse current prevention circuit 81b until it is turned on. Furthermore, during the period when the reverse current prevention circuit 81a is turned off, the control circuit 80 discharges the power generated by the power generation element 20b in the power generation circuit 50b through the discharge section 34. Similarly, after turning off the reverse current prevention circuit 81b, the control circuit 80 does not turn off the reverse current prevention circuit 81a until it is turned on. Furthermore, during the period when the reverse current prevention circuit 81b is turned off, the control circuit 80 discharges the power generated by the power generation element 20a in the power generation circuit 50a through the discharge section 34.

[0087] Furthermore, in the example of the operation described above, each of the multiple reverse current prevention circuits 81a and 81b is configured as a switch. However, even when each of the multiple reverse current prevention circuits 81a and 81b is configured as a diode, the same rotational position detection process can still be performed. In this case, the switching on and off of the multiple reverse current prevention circuits 81a and 81b is not controlled by the control circuit 80; for example, operations other than the operation of the multiple reverse current prevention circuits 81a and 81b described above can be performed. Normally, since the timing of the rise of voltage VWC1 and voltage VWC2 is different, power will not be supplied to the power supply unit 70 simultaneously from the power generation circuit 50a and the power generation circuit 50b, and reverse current can also be prevented by the function of the diode.

[0088] [Effect]

[0089] In the rotation detector 1 according to this embodiment, the control circuit 80 controls the supply of electricity generated by the power generation element 20 from the power supply unit 70 to the magnetic sensor 61 based on the voltage VWC generated by the power generation element 20, a first voltage threshold V1 for detecting the voltage VWC, and a second voltage threshold V2 for detecting the voltage VWC that is greater than the first voltage threshold. Therefore, in the rotation detector 1, it is possible to detect with high accuracy whether the power generation generated by the power generation element 20 is regular or irregular, and to determine whether to supply the electricity generated by the power generation element 20 to the magnetic sensor 61. As a result, it is possible to suppress the occurrence of false detections of rotation position in the rotation position detection unit 60. For this purpose, using... Figure 6 as well as Figure 7 Let me explain in detail.

[0090] Figure 6 as well as Figure 7 This is a graph used to illustrate the relationship between the voltage generated by the power generation element 20 and the voltage threshold. Figure 6 as well as Figure 7 In the diagram, the vertical axis represents the voltage generated by the generator element 20, and the horizontal axis represents time.

[0091] like Figure 6 As shown, the power generation element 20 generates electricity using the Big Backhausen effect. Therefore, in the voltage waveform Pr1 of regular power generation, the voltage rises very quickly, reaching a high voltage. On the other hand, the generation method of the Big Backhausen effect sometimes varies depending on external environments. Therefore, in the power generation element 20, waveforms such as Pi1 (which is based on the Big Backhausen effect but achieves a low voltage) and Pi2 (which is obtained from induction power generation not based on the Big Backhausen effect and achieves a low voltage) based on irregular power generation may also be generated. Furthermore, as... Figure 7As shown, although the voltage reached is high, since it is not based on the Big Backhausen effect of induction generation, it is also possible to generate voltage waveform Pi3 caused by irregular generation such as a slower voltage rise.

[0092] Here, the first voltage threshold V1 is set to the voltage required to stabilize the clock output by the oscillator 90, and the second voltage threshold V2 is set to the voltage required to supply the power needed for the rotational position detection process performed by the rotational position detection unit 60. If the voltage generated by the power generation element 20 does not exceed the first voltage threshold V1, the initialization of the internal clock of the rotational detector 1 cannot proceed normally, thus raising concerns that the operation of each circuit of the rotational detector 1 may not be performed as intended. For example, there may be instability due to circuit path switching on / off states, uncertain output states, etc., preventing circuits receiving power supplied based on power generation from performing their intended operations. Furthermore, in cases where waveforms Pi1 and Pi2 based on irregularly generated voltages exist, even if the voltage obtained by the power generation element 20 exceeds the first voltage threshold V1 but does not exceed the second voltage threshold V2, the rotational position detection process performed by the rotational position detection unit 60 may not proceed normally. Furthermore, even if the voltage generated by the power generation element 20 exceeds the first voltage threshold V1 and the second voltage threshold V2, such as waveform Pi3 based on irregular power generation voltage, if the time from reaching the first voltage threshold V1 to reaching the second voltage threshold V2 is long, sufficient power may not be supplied to the rotational position detection unit 60 during rotational position detection processing. Moreover, if rotational position detection processing is performed after waiting for the second voltage threshold V2 to be reached, the processing may not be completed within the specified time, potentially causing obstacles in the operation of the rotation detector 1.

[0093] Based on the above, when irregular power generation occurs in the power generation element 20, false detections of rotational position in the rotational position detection unit 60 are prone to occur. However, by detecting whether irregular power generation has occurred based on voltage VWC, false detections of rotational position can be suppressed. However, if only one of the first voltage threshold V1 and the second voltage threshold V2 is used to detect irregular power generation based on the power generation element 20, the accuracy of irregular power generation detection becomes low. In the rotation detector 1 according to this embodiment, the control circuit 80 makes a determination based on the detection results based on the first voltage threshold V1 and the detection results based on the second voltage threshold V2. Therefore, when the internal clock of the rotation detector 1 is initialized and the voltage required for the rotational position detection processing performed by the rotational position detection unit 60 is ensured, the power obtained by the power generation element 20 can be supplied to the magnetic sensor 61 to perform rotational position detection. In addition, the control circuit 80 can also determine whether the required voltage has been reached within a specified processing time and can also suppress rotational position detection at inappropriate timing.

[0094] Furthermore, the rotation detector 1 includes multiple power generation circuits 50, multiple rotation position detection units 60, and multiple backflow prevention circuits 81a and 81b. Therefore, the multiple backflow prevention circuits 81a and 81b can prevent the power supply between the multiple power generation circuits 50 from being mutually supplied, and the power generation circuits 50 used as the power supply source and the rotation position detection units 60 used as the power supply destination for rotation position detection can be selected for rotation position detection, enabling more accurate and stable rotation position detection.

[0095] [Example of a determination method based on control circuits]

[0096] Next, an example of a method by which the control circuit 80 determines whether to supply power obtained from the power generation element 20 to the magnetic sensor 61 will be described.

[0097] Figure 8 This is a diagram illustrating an example of the waveform of the voltage generated by the power generation element 20. Figure 8 The waveform of the voltage VWC of the power stored in the energy storage unit 32 after full-wave rectification by rectifier 33 is shown. Figure 8 As shown, the voltage VWC obtained by the power generation of the power generation element 20 increases in (a) as the energy storage unit 32 is charged by the power generation of the power generation element 20; in (b) as the power of the energy storage unit 32 is consumed by the rotation position detection processing based on the rotation position detection unit 60; and in (c) as the power of the energy storage unit 32 is discharged by the discharge unit 34.

[0098] For example, as described above, the control circuit 80 measures the time Δt in the voltage detection unit 31 from the moment t1 when the voltage VWC reaches the first voltage threshold V1 to the moment t2 when it reaches the second voltage threshold V2. The time Δt can also be described as the timing interval between the voltage VWC reaching the two voltage thresholds in the voltage detection unit 31. Therefore, if the time Δt exceeds a given value, the voltage VWC slows down before reaching the second voltage threshold V2, or the voltage of VWC decreases, indicating that irregular power generation has occurred by the power generation element 20. Therefore, based on the measured time Δt, the control circuit 80 determines whether the power obtained by the power generation element 20 is supplied to the magnetic sensor 61 by the power supply unit 70. For example, when the time Δt is below the given value, the control circuit 80 supplies the power obtained by the power generation element 20 to the magnetic sensor 61 through the power supply unit 70; when the time Δt exceeds the given value, it does not supply the power obtained by the power generation element 20 to the magnetic sensor 61 through the power supply unit 70. Therefore, even in cases where power generation based on the power generation element 20 is slow to rise or where the voltage reached is low, false detection of the rotational position can be suppressed. The given value is, for example, set to a value corresponding to the rotational speed of the rotational shaft 16, which ensures the time for rotational position detection processing based on the rotational position detection unit 60.

[0099] Furthermore, the control circuit 80 can also calculate the slew rate based on the aforementioned time Δt and ΔV, which is the difference between the first voltage threshold V1 and the second voltage threshold V2. The slew rate is ΔV / Δt. If the slew rate is less than a given value, it can be determined that irregular power generation has occurred by the power generation element 20. The control circuit 80 uses this slew rate to determine whether power is supplied to the magnetic sensor 61 by the power supply unit 70. For example, if the slew rate is greater than or equal to the given value, the control circuit 80 supplies the power obtained from power generation by the power generation element 20 to the magnetic sensor 61 through the power supply unit 70; if the slew rate is less than the given value, the control circuit 80 does not supply the power obtained from power generation by the power generation element 20 to the magnetic sensor 61 through the power supply unit 70. By using the slew rate for determination, it is possible to easily determine even if the power generation element 20 generates power with a slow voltage rise, which is not based on the Big Backhausen effect.

[0100] Furthermore, in the above description, the voltage detection unit 31 has been described as having two voltage thresholds, namely the first voltage threshold V1 and the second voltage threshold V2. However, the voltage detection unit 31 may also have one or more other voltage thresholds that are different from the first voltage threshold V1 and the second voltage threshold V2.

[0101] Figure 9This diagram illustrates the case where the voltage detection unit 31 has three or more voltage thresholds. Figure 9 In, with Figure 8 Similarly, the waveform of voltage VWC obtained based on the power stored in the energy storage unit 32 after full-wave rectification by rectifier 33 is shown. Furthermore, in Figure 9 In the diagram, examples of normal voltage VWC waveforms are shown with solid lines, while examples of abnormal voltage VWC waveforms are shown with dashed lines.

[0102] exist Figure 9 In the example shown, the voltage detection unit 31 has a first voltage threshold V1, a second voltage threshold V2, and additional voltage thresholds Vx1 and Vx2 having values ​​between the first voltage threshold V1 and the second voltage threshold V2. That is, the voltage detection unit 31 outputs the detection results based on the first voltage threshold V1, the second voltage threshold V2, and the additional voltage thresholds Vx1 and Vx2 to the control circuit 80. In this case, the control circuit 80, in its normal mode, as described above, determines, based on time Δt, whether the power obtained by the power generation element 20 from the power supply unit 70 should be supplied to the magnetic sensor 61. This normal mode is an example of the first control mode.

[0103] On the other hand, in another mode, for example, the control circuit 80 controls the power generation obtained by the power generation element 20 to be supplied from the power supply unit 70 to the magnetic sensor 61 based on the voltage VWC generated by the power generation element 20, the first voltage threshold V1, and other voltage thresholds Vx1 and Vx2. Specifically, the control circuit 80 measures, for example, the time Δx from when the voltage VWC reaches the first voltage threshold V1 to when it reaches the other voltage threshold Vx1, and determines whether the power supply unit 70 should supply the power generated by the power generation element 20 to the magnetic sensor 61 based on the measured time Δx. This other mode is an example of the second control mode. In the determination, the time Δx can be used directly, or, as described above, the conversion rate calculated based on the time Δx can be used. Since the time Δx is shorter than the time Δt, the time from when the voltage VWC reaches the first voltage threshold V1 to when the control circuit 80 makes the above determination can be shortened. For example, in the case where irregular power generation occurs in the power generation element 20, the waveform can be used to... Figure 9 In the example shown by the dashed line, when the shape is stable, even if time Δx is used for the determination, the detection accuracy of whether it is irregular power generation will not decrease, and a determination can be made in a short time. The control circuit 80 switches these modes, for example, based on input from the user's input interface.

[0104] also, Figure 10 This is another diagram illustrating the case where the voltage detection unit 31 has three or more voltage thresholds. Figure 10In, with Figure 8 Similarly, the waveform of the voltage VWC of the power stored in the energy storage unit 32 after full-wave rectification by rectifier 33 is shown. Furthermore, in Figure 10 In the diagram, examples of normal voltage VWC waveforms are shown with solid lines, while examples of abnormal voltage VWC waveforms are shown with dashed lines.

[0105] exist Figure 10 In the example shown, the voltage detection unit 31 has a first voltage threshold V1, a second voltage threshold V2, and additional voltage thresholds Vx1, Vx2, and Vx3 having values ​​between the first voltage threshold V1 and the second voltage threshold V2. That is, the voltage detection unit 31 outputs the detection results based on the first voltage threshold V1, the second voltage threshold V2, and the additional voltage thresholds Vx1, Vx2, and Vx3 to the control circuit 80. The control circuit 80 controls the power generation by the power generation element 20 to supply electricity from the power supply unit 70 to the magnetic sensor 61, based on the voltage VWC generated by the power generation element 20, the first voltage threshold V1, the second voltage threshold V2, and the additional voltage thresholds Vx1, Vx2, and Vx3. Specifically, the control circuit 80 determines, for example, whether the power supply unit 70 should supply the power obtained by the power generation element 20 to the magnetic sensor 61 based on the detection results of the voltage detection unit 31 based on the first voltage threshold V1, the detection results based on the second voltage threshold V2, and the detection results based on other voltage thresholds Vx1, Vx2, and Vx3.

[0106] For example, the control circuit 80 measures the timing intervals at which the voltage VWC reaches the first voltage threshold V1, the second voltage threshold V2, and other voltage thresholds Vx1, Vx2, and Vx3 (in... Figure 10 In the example shown, the time interval is from Δx1 to Δx4. For example, if all of the time intervals from Δx1 to Δx4 are within the given range, the control circuit 80 supplies the power generated by the power generation element 20 to the magnetic sensor 61 through the power supply unit 70. If at least one of the time intervals from Δx1 to Δx4 deviates from the given range, the control circuit 80 does not supply the power generated by the power generation element 20 to the magnetic sensor 61 through the power supply unit 70. Furthermore, the control circuit 80 can also make the above determination based on the deviation between time intervals from Δx1 to Δx4. As a result, it is possible to detect waveform disturbances of the voltage VWC between the first voltage threshold V1 and the second voltage threshold V2, thus improving the accuracy of irregular power generation detection. For example, in Figure 10In the case of the voltage VWC waveform shown by dashed lines, the interval between reaching the first voltage threshold V1 and the timing of reaching another voltage threshold Vx1 is shorter than Δx1 in the normal voltage VWC waveform. However, the deviations in the timing intervals of voltage VWC reaching the first voltage threshold V1, the second voltage threshold V2, and the other voltage thresholds Vx1, Vx2, and Vx3 are large. Therefore, irregular power generation can be detected by the above method.

[0107] Furthermore, the control circuit 80 can also determine whether a cause other than irregular power generation by the power generation element 20 has occurred, such as in... Figure 10 The waveform of voltage VWC, as shown by the dashed line, can be disturbed due to load changes, noise, or leakage current, and faults in the rotating detector 1 can also be detected.

[0108] [Variation Example]

[0109] Next, a variation of the rotating detector related to the embodiment will be described. In the following description of the variation, the focus will be on the differences from the embodiment, and the description of the commonalities will be omitted or simplified.

[0110] Figure 11 This is a diagram illustrating the circuit structure of the rotation detector 101 involved in this modified example. (See diagram for details.) Figure 11 As shown, the rotation detector 101 in this modified example differs from the rotation detector 1 in the embodiment in that it has multiple power generation circuits 150 instead of multiple power generation circuits 50. The power generation circuits 150 have the following structure relative to the power generation circuits 50: they have a power storage unit 132 instead of a power storage unit 32, and also have a capacity adjustment unit 135.

[0111] The capacity of the energy storage unit 132 is variable. The energy storage unit 132 may be composed of, for example, a variable capacitor element. The energy storage unit 132 may also have multiple capacitor elements with fixed capacitance and a switch, by which the number of capacitor elements storing the electricity generated by the power generation element 20 is changed, thereby making the capacity variable.

[0112] The capacity adjustment unit 135 is a processing circuit that adjusts the capacity of the energy storage unit 132. The capacity adjustment unit 135 can be implemented, for example, by a memory and a processor. Alternatively, the capacity adjustment unit 135 can be implemented by a dedicated logic circuit that performs capacity adjustment processing on the energy storage unit 132. Furthermore, multiple power generation circuits 150 can share the capacity adjustment unit 135.

[0113] In the rotary detector 101, the waveform of the voltage VWC can be adjusted by the variable capacity of the energy storage unit 132. Figure 12 This is a graph illustrating the relationship between the capacity of the energy storage unit 132 and the waveform of the voltage VWC. Figure 12In the diagram, the waveform of voltage VWC when the capacity of the energy storage unit 132 is relatively small is shown as a solid line, while the waveform of voltage VWC when the capacity of the energy storage unit 132 is relatively large is shown as a dashed line. In the rotation detector 101, the waveform of voltage VWC can be changed by adjusting the capacity of the energy storage unit 132.

[0114] The voltage VWC of the electricity generated by the power generation element 20 has a wave height value Vmax, which is expressed by the following equation (1) or equation (2).

[0115] [Mathematical Expression 1]

[0116]

[0117] [Mathematical Expression 2]

[0118]

[0119] Here, C is the capacity of the energy storage unit 132, R is the load resistance between the power generation element 20 and the energy storage unit 132, t is the charging time of the energy storage unit 132 (that is, the time from the start of power generation by the power generation element 20 to the start of the rotational position detection process of the rotational position detection unit 60), W is the energy stored in the energy storage unit 132, and Q is the amount of charge stored in the energy storage unit 132. The energy W and the amount of charge Q are determined based on the power generation of the power generation element 20, and the load resistance R is also fixed. Therefore, according to equations (1) and (2), the wave height value Vmax and the time constant can be adjusted by the capacity C of the energy storage unit 132.

[0120] like Figure 12 As shown by the solid line waveform, when the capacity C of the energy storage unit 132 is small, the voltage VWC rises rapidly, and the peak value Vmax1 increases. On the other hand, as... Figure 12 As shown by the dashed line waveform, when the capacity C of the battery storage unit 132 is large, the voltage VWC rises slowly, and the peak value Vmax2 decreases. The capacity C of the battery storage unit 132 needs to be set to a size that can supply the power consumed by the rotational position detection unit 60 during rotational position detection processing. However, if the capacity C of the battery storage unit 132 is too large, not only will the voltage VWC rise slowly, but the peak value Vmax will also decrease. In the rotational detector 101, since the capacity C of the battery storage unit 132 can be adjusted, it can be adjusted to an appropriate capacity C corresponding to the power consumed by the rotational position detection processing and the time of rotational position detection processing. For example, during the initial setting or calibration of the rotational detector 101, the capacity adjustment unit 135 adjusts the capacity C of the battery storage unit 132 based on the input from the user's input interface. As a result, the occurrence of false detections in the rotational position detection processing can be further suppressed.

[0121] Furthermore, the capacity adjustment unit 135 can also adjust the capacity of the energy storage unit 132 based on the history of voltage VWC detection results by the voltage detection unit 31. For example, the voltage detection unit 31 outputs the voltage VWC detection results based on each voltage threshold, the capacity adjustment unit 135 acquires the output detection results, and saves the voltage VWC detection results in memory. Then, the capacity adjustment unit 135 adjusts the capacity of the energy storage unit 132 based on the history of voltage VWC detection results saved in memory. The voltage VWC detection results can also be saved in memory by the control circuit 80. For example, the capacity adjustment unit 135 adjusts the capacity of the energy storage unit 132 based on the history of the time Δt from when the voltage VWC reaches the first voltage threshold V1 to when it reaches the second voltage threshold V2.

[0122] For example, consider the following situation: Let the time Δt from reaching the first voltage threshold V1 to reaching the second voltage threshold V2 be denoted as... Figure 12 The rotational position detection process is performed when the waveform of voltage VWC, shown as a solid line, is below time Δt1. At this time, if the time Δt in the history representation of the voltage VWC detection result is below time Δt1, the capacity adjustment unit 135 does not adjust the capacity C of the energy storage unit 132. On the other hand, if the time Δt in the history representation of the voltage VWC detection result is below time Δt1, the capacity adjustment unit 135 does not adjust the capacity C of the energy storage unit 132. Figure 12 When the waveform of voltage VWC, shown by the dashed line, is greater than the time Δt2 of time Δt1, the capacity C of the energy storage unit 132 is reduced. Therefore, the waveform of voltage VWC is adjusted to become... Figure 12 The waveform of voltage VWC is shown as a solid line. In other words, by adjusting the capacity C of the energy storage unit 132 to an appropriate value corresponding to the power consumed by the rotational position detection process and the time for performing the rotational position detection process, the occurrence of false detections in the rotational position detection process can be further suppressed.

[0123] There is no particular limitation on the frequency at which the capacity adjustment unit 135 adjusts the capacity C of the energy storage unit 132 based on the history of voltage VWC detection results. For example, whenever a given number of voltage VWC detection results are stored in the memory, the capacity adjustment unit 135 adjusts the capacity C of the energy storage unit 132 based on the history of voltage VWC detection results.

[0124] Furthermore, the history of the voltage VWC detection result obtained by the voltage detection unit 31 used by the capacity adjustment unit 135 in adjusting the capacity C of the energy storage unit 132 is not limited to the history of detection results based on the first voltage threshold V1 or the history of detection results based on the second voltage threshold V2. For example, using... Figure 9 as well as Figure 10As explained, when the voltage detection unit 31 has an additional voltage threshold, the history of the detection results of the voltage VWC obtained by the voltage detection unit 31 may also include the history of detection results based on the additional voltage threshold. The capacity adjustment unit 135 may also be based on, for example, using... Figure 9 The capacity C of the energy storage unit 132 is adjusted based on the time history Δx. Thus, the capacity C of the energy storage unit 132 can be adjusted according to the time history Δx, which readily reflects the rise in voltage VWC.

[0125] (other)

[0126] The above description of the rotating detector involved in this disclosure is based on embodiments and modifications, but this disclosure is not limited to the above embodiments and modifications. Various modifications conceived by those skilled in the art to the above embodiments and modifications, and implementation methods by arbitrarily combining the constituent elements and functions of each embodiment without departing from the spirit of this disclosure, are also included in this disclosure.

[0127] For example, in the above embodiments and variations, the number of power generation circuits 50 and the number of rotation position detection units 60 in the rotation detector 1 can each be one. Similarly, the number of power generation circuits 150 and the number of rotation position detection units 60 in the rotation detector 101 can each be one. Furthermore, in this case, the rotation detectors 1 and 101 may not each have multiple backflow prevention circuits 81a and 81b. In this case, the control circuit 80 also controls, for example, whether the discharge unit 34 discharges the power stored in the energy storage unit 32, thereby controlling the supply of power generated by the power generation element 20 from the power supply unit 70 to the magnetic sensor 61.

[0128] Furthermore, for example, in the above embodiments and variations, the voltage detection unit 31 is configured with a comparator corresponding to each voltage threshold, but is not limited thereto. For example, the voltage detection unit 31 may also be a voltage detector that detects the voltage value of voltage VWC. The voltage detection unit 31 outputs the voltage value of voltage VWC at given time intervals, for example. In this case, the control circuit 80 controls the supply of electricity obtained by the power generation element 20 from the power supply unit 70 to the magnetic sensor 61 based on the voltage value of voltage VWC detected by the voltage detection unit 31 and each voltage threshold. The control circuit 80, for example, uses the detected voltage value of voltage VWC to measure the time Δt from when voltage VWC reaches the first voltage threshold V1 to when it reaches the second voltage threshold V2, and determines whether the measured time Δt is a given value.

[0129] Furthermore, in the above embodiments and variations, the processing performed by specific processing units such as the information processing unit 62, the control circuit 80, and the capacity adjustment unit 135 can also be performed by another processing unit. Moreover, the order of multiple processes can be changed, or multiple processes can be executed in parallel.

[0130] Furthermore, in the above embodiments and variations, all or part of the processing units such as the information processing unit 62, the control circuit 80, and the capacity adjustment unit 135 may be constructed using dedicated hardware, or they may be implemented by executing software programs suitable for each processing unit. Each processing unit may also be implemented by reading and executing software programs recorded on recording media such as semiconductor memory using a program execution unit such as a CPU (Central Processing Unit) or processor.

[0131] Furthermore, the information processing unit 62, the control circuit 80, and the capacity adjustment unit 135, etc., can also be composed of one or more electronic circuits. These one or more electronic circuits can be general-purpose circuits or dedicated circuits.

[0132] In one or more electronic circuits, for example, semiconductor devices, integrated circuits (ICs), or large-scale integrated circuits (LSIs) may be included. ICs or LSIs can be integrated onto a single chip or multiple chips. Here, although called ICs or LSIs, the terminology varies depending on the degree of integration; they may also be called system LSIs, very large-scale integrated circuits (VLSIs), or ultra-large-scale integrated circuits (ULSIs). Furthermore, field-programmable gate arrays (FPGAs) can be used for the same purpose after the LSI is manufactured.

[0133] Furthermore, the general or specific embodiments of this disclosure may also be implemented by a system, apparatus, method, integrated circuit, or computer program. Alternatively, it may be implemented by a computer-readable non-transitory recording medium such as an optical disc, HDD (Hard Disk Drive), or semiconductor memory storing the computer program. Furthermore, it may be implemented by any combination of system, apparatus, method, integrated circuit, computer program, and recording medium.

[0134] The following examples of a rotary detector according to the present disclosure are shown based on the embodiments described above and variations thereof. The rotary detectors according to the present disclosure are not limited to the examples described below.

[0135] For example, the rotation detector according to the first aspect of this disclosure includes a magnet, a first power generation circuit, a first rotational position detection unit, a power supply unit, and a control circuit. The magnet rotates about a given axis. The first power generation circuit includes a first power generation element, a voltage detection unit, and a storage unit. The first power generation element generates electricity using the Big Backhausen effect, which is generated by the change in the magnetic field caused by the rotation of the magnet about the given axis. The voltage detection unit detects the voltage generated by the first power generation element. The storage unit stores the first power obtained by the power generation element. The first rotational position detection unit includes a first magnetic sensor and a first information processing unit. The first magnetic sensor detects the magnetic field generated by the magnet and is positioned corresponding to the first power generation element. The first information processing unit determines the rotational position of the rotation axis based on the detection result of the first magnetic sensor. The power supply unit supplies the first power to the first magnetic sensor. The control circuit controls the supply of the first power by the power supply unit. Furthermore, the control circuit controls the supply of the first power from the power supply unit to the first magnetic sensor based on the voltage generated by the first power generation element, a first voltage threshold for detecting the voltage, and a second voltage threshold for detecting the voltage that is greater than the first voltage threshold.

[0136] Furthermore, for example, the rotary detector according to the second aspect of this disclosure is the rotary detector according to the first aspect, and has the following structure. That is, the voltage detection unit has the first voltage threshold and the second voltage threshold as voltage thresholds for detecting the voltage. The control circuit controls the supply of the first power from the power supply unit to the first magnetic sensor based on the detection result based on the first voltage threshold and the detection result based on the second voltage threshold in the voltage detection unit.

[0137] Furthermore, for example, the rotary detector involved in the third aspect of this disclosure is the rotary detector involved in the first or second aspect, wherein the control circuit measures the time from when the voltage reaches the first voltage threshold to when it reaches the second voltage threshold in the voltage detection unit, and determines whether to supply the first power from the power supply unit to the first magnetic sensor based on the measured time.

[0138] Furthermore, for example, the rotation detector involved in the fourth aspect of this disclosure is the rotation detector involved in the third aspect, wherein the control circuit calculates a conversion rate based on the time, the first voltage threshold, and the second voltage threshold, and uses the conversion rate to determine whether to supply the first power from the power supply unit to the first magnetic sensor.

[0139] Furthermore, for example, the rotation detector involved in the fifth aspect of this disclosure is a rotation detector involved in any of the first to fourth aspects, and the control circuit has a first control mode and a second control mode. The first control mode controls the supply of first power from the power supply unit to the first magnetic sensor based on the voltage generated by the first power generation element, the first voltage threshold, and the second voltage threshold. The second control mode controls the supply of first power from the power supply unit to the first magnetic sensor based on the voltage generated by the first power generation element, the first voltage threshold, and one or more additional voltage thresholds different from the first voltage threshold and the second voltage threshold for detecting the voltage.

[0140] Furthermore, for example, the rotation detector involved in the sixth aspect of this disclosure is the rotation detector involved in any of the first to fifth aspects, wherein the control circuit controls the supply of the first power from the power supply unit to the first magnetic sensor based on the voltage generated by the first power generation element, the first voltage threshold, the second voltage threshold, and one or more additional voltage thresholds between the first voltage threshold and the second voltage threshold for detecting the voltage.

[0141] Furthermore, for example, the rotating detector involved in the seventh aspect of this disclosure is the rotating detector involved in any of the first to sixth aspects, and the first power generation circuit further includes: a discharge section for discharging the first power stored in the power storage section.

[0142] Furthermore, for example, the rotation detector involved in the eighth aspect of this disclosure is the rotation detector involved in the seventh aspect, wherein the control circuit controls whether the first power stored in the energy storage unit is discharged by the discharge unit based on the voltage generated by the first power generation element, the first voltage threshold and the second voltage threshold, thereby controlling the supply of the first power from the power supply unit to the first magnetic sensor.

[0143] Furthermore, for example, the rotation detector according to the ninth aspect of this disclosure is the rotation detector according to the eighth aspect, wherein the control circuit measures the time from when the voltage reaches the first voltage threshold to when it reaches the second voltage threshold in the voltage detection unit, and controls whether the discharge unit discharges the first power stored in the energy storage unit based on the measured time.

[0144] Furthermore, for example, the rotary detector involved in the 10th aspect of this disclosure is the rotary detector involved in any of the 1st to 9th aspects, and the capacity of the energy storage unit is variable.

[0145] Furthermore, for example, the rotary detector according to the 11th aspect of this disclosure is the rotary detector according to the 10th aspect, and the first power generation circuit further includes: a capacity adjustment unit that adjusts the capacity of the energy storage unit based on the history of the detection results of the voltage obtained by the voltage detection unit.

[0146] Furthermore, for example, the rotary detector involved in the 12th aspect of this disclosure is the rotary detector involved in the 5th or 6th aspect, the capacity of the energy storage unit is variable, and the first power generation circuit further includes: a capacity adjustment unit that adjusts the capacity of the energy storage unit based on the history of the detection results of the voltage obtained by the voltage detection unit.

[0147] Furthermore, for example, the rotation detector involved in the 13th aspect of this disclosure is the rotation detector involved in any of the 1st to 12th aspects, wherein the voltage detection unit outputs a signal that triggers the initialization of the internal clock of the rotation detector when the voltage reaches the first voltage threshold.

[0148] Furthermore, for example, the rotation detector according to the 14th aspect of this disclosure is a rotation detector according to any of the 1st to 13th aspects, and the rotation detector further includes a second power generation circuit, a second position detection unit, and a backflow prevention circuit. The second power generation circuit has a second power generation element that generates electricity using the large Backhausen effect caused by the change in the magnetic field resulting from the rotation of the magnet around the given axis. The second power obtained by generating electricity from the second power generation element is supplied to the power supply unit, and it is connected in parallel with the first power generation circuit. The second rotation position detection unit has a second magnetic sensor and a second information processing unit. The second magnetic sensor receives the second power from the power supply unit, detects the magnetic field generated by the magnet, and is positioned corresponding to the second power generation element. The second information processing unit determines the rotational position of the rotating axis based on the detection result of the second magnetic sensor. The backflow prevention circuit is provided between the second power generation circuit and the power supply unit, and prevents the supply of the first power from the first power generation circuit to the second power generation circuit.

[0149] Industrial availability

[0150] The rotation detector disclosed herein can be used, for example, to detect the rotation of the rotating shaft of a motor that drives a load to rotate. Therefore, the rotation detector disclosed herein is useful in industry.

[0151] Explanation of reference numerals in the attached figures

[0152] 1. 101 Rotary Detector

[0153] 10 Magnets

[0154] 11 Main side

[0155] 15 Rotating Plate

[0156] 16 Rotational axes

[0157] 17 substrate

[0158] 20, 20a, 20b power generation elements

[0159] 21 Magnetic components

[0160] 22 coils

[0161] 23. Shell

[0162] 24, 25 terminals

[0163] 31 Voltage Detection Section

[0164] 32, 132 Battery Storage Unit

[0165] 33 Rectifier

[0166] 34 Discharge section

[0167] 50, 50a, 50b, 150 Generating Circuits

[0168] Rotary position detection unit 60, 60a, 60b

[0169] Magnetic sensors 61, 61a, and 61b

[0170] 62 Information Processing Department

[0171] 70 Power Supply Department

[0172] 80 Control Circuit

[0173] 81a, 81b Backflow Prevention Circuit

[0174] 90 Oscillator

[0175] 135 Capacity Adjustment Section.

Claims

1. A rotating detector, comprising: A magnet, rotating about a given axis; The first power generation circuit includes: a first power generation element that generates electricity using the Big Backhausen effect, which is produced by the change in the magnetic field caused by the rotation of the magnet around the given axis; a voltage detection unit that detects the voltage generated by the first power generation element; and an energy storage unit that stores the first power obtained by the power generation of the first power generation element. The first rotational position detection unit includes: a first magnetic sensor that detects the magnetic field generated by the magnet and is provided corresponding to the first power generation element; And the first information processing unit determines the rotational position of the rotating shaft based on the detection result of the first magnetic sensor; The power supply unit supplies the first power to the first magnetic sensor; and The control circuit controls the supply of the first power by the power supply unit. The control circuit controls the supply of the first power from the power supply unit to the first magnetic sensor based on the voltage generated by the first power generation element, a first voltage threshold for detecting the voltage, and a second voltage threshold for detecting the voltage that is greater than the first voltage threshold.

2. The rotating detector according to claim 1, wherein, The voltage detection unit has the first voltage threshold and the second voltage threshold as voltage thresholds for detecting the voltage. The control circuit controls the supply of the first power from the power supply unit to the first magnetic sensor based on the detection results of the voltage detection unit based on the first voltage threshold and the detection results based on the second voltage threshold.

3. The rotating detector according to claim 1, wherein, The control circuit measures the time from when the voltage reaches the first voltage threshold to when it reaches the second voltage threshold in the voltage detection unit, and determines whether to supply the first power from the power supply unit to the first magnetic sensor based on the measured time.

4. The rotating detector according to claim 3, wherein, The control circuit calculates the conversion rate based on the time, the first voltage threshold, and the second voltage threshold, and uses the conversion rate to determine whether to supply the first power from the power supply unit to the first magnetic sensor.

5. The rotating detector according to claim 1, wherein, The control circuit has: In the first control mode, the supply of the first power from the power supply unit to the first magnetic sensor is controlled based on the voltage generated by the first power generation element, the first voltage threshold, and the second voltage threshold. and In the second control mode, the supply of the first power from the power supply unit to the first magnetic sensor is controlled based on the voltage generated by the first power generation element, the first voltage threshold, and one or more additional voltage thresholds different from the first voltage threshold and the second voltage threshold for detecting the voltage.

6. The rotating detector according to claim 1, wherein, The control circuit controls the supply of the first power from the power supply unit to the first magnetic sensor based on the voltage generated by the first power generation element, the first voltage threshold, the second voltage threshold, and one or more additional voltage thresholds between the first voltage threshold and the second voltage threshold for detecting the voltage.

7. The rotating detector according to claim 1, wherein, The first power generation circuit further includes a discharge section for discharging the first electrical energy stored in the energy storage section.

8. The rotating detector according to claim 7, wherein, The control circuit controls whether the discharge section discharges the first power stored in the energy storage section based on the voltage generated by the first power generation element, the first voltage threshold, and the second voltage threshold, thereby controlling the supply of the first power from the power supply section to the first magnetic sensor.

9. The rotating detector according to claim 8, wherein, The control circuit measures the time from when the voltage reaches the first voltage threshold to when it reaches the second voltage threshold in the voltage detection unit, and controls whether the discharge unit discharges the first power stored in the energy storage unit based on the measured time.

10. The rotating detector according to claim 1, wherein, The capacity of the energy storage unit is variable.

11. The rotating detector according to claim 10, wherein, The first power generation circuit further includes a capacity adjustment unit that adjusts the capacity of the energy storage unit based on the history of voltage detection results obtained by the voltage detection unit.

12. The rotating detector according to claim 5, wherein, The capacity of the energy storage unit is variable. The first power generation circuit further includes a capacity adjustment unit that adjusts the capacity of the energy storage unit based on the history of voltage detection results obtained by the voltage detection unit.

13. The rotating detector according to claim 1, wherein, When the voltage reaches the first voltage threshold, the voltage detection unit outputs a signal that triggers the initialization of the internal clock of the rotary detector.

14. The rotating detector according to any one of claims 1 to 13, wherein, The rotating detector also features: The second power generation circuit has a second power generation element that generates electricity by utilizing the large Backhausen effect caused by the change in the magnetic field resulting from the rotation of the magnet around the given axis, supplies the second power obtained by the second power generation element to the power supply unit, and is connected in parallel with the first power generation circuit. The second rotational position detection unit includes: a second magnetic sensor, which receives a second power supply from the power supply unit, detects the magnetic field generated by the magnet, and is provided corresponding to the second power generation element; and a second information processing unit, which determines the rotational position of the rotating shaft based on the detection result of the second magnetic sensor. and A reverse current prevention circuit is provided between the second power generation circuit and the power supply unit, and prevents the first power from being supplied from the first power generation circuit to the second power generation circuit.

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