Motor

Abstract

A motor having a first terminal and a second terminal to which a single-phase alternating current is to be input, the motor comprising: a third terminal; an AC / DC converter for converting the single-phase alternating current into a direct current; an inverter for inverting the direct current into a three-phase alternating current by PWM control with PWM signals; a control unit for outputting the PWM signals to the inverter; and a detection circuit connected to the third terminal. The detection circuit outputs any one of a first detection signal, a second detection signal, and a third detection signal in accordance with a state of the third terminal. The control unit outputs the PWM signals so that a first rotation state is achieved when the detection circuit is outputting the first detection signal, a second rotation state is achieved when the detection circuit is outputting the second detection signal, and a third rotation state is achieved when the detection circuit is outputting the third detection signal.

Description

[Technical field]

[0001] The present disclosure relates to a motor. [Background technology]

[0002] 2. Description of the Related Art Conventionally, motors equipped with a pair of terminals for supplying power are known (see, for example, Patent Document 1).

[0003] In general, it is desirable for a motor to have a relatively small number of terminals. For this reason, in a motor capable of dynamically switching between a plurality of operating modes with mutually different rotation states, there is a demand to reduce the number of terminals used for dynamically switching between the operating modes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 008924 Summary of the Invention

[0005] In view of this, the present disclosure provides a motor capable of dynamically switching between three operating modes with mutually different rotation states. The present disclosure has an object to provide a motor having one terminal in addition to a pair of terminals for power supply.

[0006] A motor according to an aspect of the present disclosure includes a first terminal and a second terminal to which a single-phase AC is input, a third terminal, an AC / DC converter connected to the first terminal and the second terminal and configured to convert the single-phase AC to a direct current, an inverter configured to convert the direct current to a three-phase AC by being pulse-width modulated (PWM controlled) using a pulse-width modulated signal (PWM signal), a winding to which the three-phase AC is supplied, a rotor that rotates due to a magnetic field generated in the winding, a control unit that outputs the PWM signal to the inverter, and a detection circuit connected to the third terminal, wherein the detection circuit detects when the single-phase AC is input to the first terminal and the second terminal. In a state in which the detection circuit is in an open state, (1) a first detection signal is output when the third terminal is shorted to the first terminal, (2) a second detection signal is output when the third terminal is shorted to the second terminal, and (3) a third detection signal is output when the third terminal is in an open state, and the control unit outputs the PWM signal so that the rotor is in a first rotation state when the detection circuit outputs the first detection signal, the rotor is in a second rotation state when the detection circuit outputs the second detection signal, and the rotor is in a third rotation state when the detection circuit outputs the third detection signal.

[0007] The above configuration provides a motor that can dynamically switch between three operation modes having mutually different rotation states, and that has one more terminal in addition to a pair of terminals for power supply. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing an example of the configuration of a motor drive system according to a first embodiment. [Figure 2A] FIG. 2A is a waveform diagram of a single-phase AC current supplied from a single-phase AC power supply. [Figure 2B] FIG. 2B is a waveform diagram of the detection signal line. [Figure 3A] FIG. 3A is a waveform diagram of a single-phase AC current supplied from a single-phase AC power supply. [Figure 3B]FIG. 3B is a waveform diagram of the detection signal line in a state in which the third terminal is shorted to the second terminal. [Figure 4A] FIG. 4A is a waveform diagram of a single-phase AC current supplied from a single-phase AC power supply. [Figure 4B] FIG. 4B is a waveform diagram of the detection signal line when the third terminal is in an open state. [Diagram 5] FIG. 5 is a block diagram showing an example of the configuration of a motor drive system according to the second embodiment. As shown in FIG. [Figure 6A] FIG. 6A is a waveform diagram of a single-phase AC current supplied from a single-phase AC power supply. [Figure 6B] FIG. 6B is a waveform diagram of the detection signal line. [Figure 7A] FIG. 7A is a waveform diagram of a single-phase AC current supplied from a single-phase AC power supply. [Figure 7B] FIG. 7B is a waveform diagram of the detection signal line in a state in which the third terminal is shorted to the second terminal. [Figure 8] FIG. 8 is a block diagram showing an example of the configuration of a motor drive system according to the third embodiment. [Figure 9A] FIG. 9A is a waveform diagram of a single-phase AC current supplied from a single-phase AC power supply. [Figure 9B] FIG. 9B is a waveform diagram of the detection signal line when the third terminal 13 is in an open state. [Figure 10A] FIG. 10A is a waveform diagram of a single-phase AC current supplied from a single-phase AC power supply. [Figure 10B] FIG. 10B is a waveform diagram of the detection signal line in a state in which the third terminal is shorted to the first terminal. [Figure 11A] FIG. 11A is a waveform diagram of a single-phase AC current supplied from a single-phase AC power supply. [Figure 11B] FIG. 11B is a waveform diagram of the detection signal line. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (How one aspect of the present disclosure was achieved) 2. Description of the Related Art Conventionally, motors have been used in cooling devices (such as freezer showcases) for cold chain applications that handle products in a cooled state.

[0010] In a cooling device, in order to realize an operation of switching between strong and weak airflow, an operation of switching to a defrosting operation, etc., it is necessary to dynamically switch the operation mode of a motor. For example, an operation of switching between strong and weak airflow is realized by dynamically switching between operation modes of the motor having different rotation speeds. Also, for example, an operation of switching to a defrosting operation is realized by dynamically switching between operation modes of the motor having different rotation directions.

[0011] On the other hand, it is desirable for the motor used in the cooling device to have a relatively small number of terminals.

[0012] Therefore, the inventors conducted extensive experiments and studies to find a configuration that can reduce the number of terminals other than the pair of terminals for power supply in a motor that can dynamically switch between different operation modes. As a result, they came up with the following motor.

[0013] A motor according to an embodiment of the present disclosure includes a first terminal and a second terminal to which a single-phase AC is input, a third terminal, an AC (Alternating Current) / DC (Direct Current) converter that converts the single-phase AC into a direct current and is connected to the first terminal and the second terminal, and a PWM (Pulse Width Modulation) / DC (Direct Current) converter that converts the single-phase AC into a direct current. the third terminal is in an open state, and the control unit outputs the PWM signal so that, in a state in which the single-phase AC is input to the first terminal and the second terminal, the detection circuit (1) outputs a first detection signal when the third terminal is short-circuited with the first terminal, (2) outputs a second detection signal when the third terminal is short-circuited with the second terminal, and (3) outputs a third detection signal when the third terminal is in an open state, and the control unit outputs the PWM signal so that the rotor is in a first rotation state when the detection circuit outputs the first detection signal, the rotor is in a second rotation state when the detection circuit outputs the second detection signal, and the rotor is in a third rotation state when the detection circuit outputs the third detection signal.

[0014] According to the motor having the above configuration, (1) the rotor is in a first rotation state by shorting the third terminal with the first terminal, (2) the rotor is in a second rotation state by shorting the third terminal with the second terminal, and (3) the rotor is in a third rotation state by opening the third terminal. Thus, according to the motor having the above configuration, a motor capable of dynamically switching between three operation modes having mutually different rotation states is provided, which has one terminal (i.e., the third terminal) in addition to a pair of terminals for power supply (i.e., the first terminal and the second terminal).

[0015] Furthermore, the first rotation state, the second rotation state, and the third rotation state may include at least a rotation state in which the rotor rotates in a first rotation direction, and a rotation state in which the rotor rotates in a second rotation direction opposite to the first rotation direction.

[0016] This allows the motor having the above configuration to operate in two operation modes in which the rotors rotate in opposite directions.

[0017] Furthermore, the motor may include a memory unit that stores PWM information that defines the waveform of the PWM signal, an update unit that updates the PWM information, and an operation reception unit that receives operations from a user of the motor, wherein the control unit outputs the PWM signal based on the PWM information, and the update unit updates the PWM information based on the operation from the user received by the operation reception unit.

[0018] This allows the motor having the above configuration to operate in an operation mode set by the user.

[0019] A specific example of a motor according to one aspect of the present disclosure will be described below with reference to the drawings. Each embodiment shown here shows one specific example of the present disclosure. Therefore, the numerical values, shapes, components, arrangement and connection of the components, steps (processes) and order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, each figure is a schematic diagram and is not necessarily a precise illustration.

[0020] In addition, the comprehensive or specific aspects of the present disclosure may be realized by a system, a method, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM (Compact Disk Read Only Memory), or may be realized by any combination of the system, the method, the integrated circuit, the computer program, and the recording medium.

[0021] (Embodiment 1) <Configuration> FIG. 1 is a block diagram showing an example of the configuration of a motor drive system 1 according to the first embodiment.

[0022] As shown in FIG. 1, the motor drive system 1 includes a motor 10 and a single-phase AC power supply 20.

[0023] The single-phase AC power supply 20 supplies a single-phase AC current to the motor 10. The single-phase AC current supplied by the single-phase AC power supply 20 has, for example, an effective voltage of 100 V and a frequency of 60 Hz. The single-phase AC power supply 20 may be, for example, a commercial power supply.

[0024] The motor 10 is driven by a single-phase AC power source supplied from a single-phase AC power source 20. The motor 10 may be, for example, an induction motor.

[0025] As shown in FIG. 1, motor 10 includes a first terminal 11, a second terminal 12, a third terminal 13, an AC / DC converter 30, an inverter 40, a winding 50, a rotor 60, a control unit 70, a memory unit 71, an update unit 72, an operation receiving unit 73, and a detection circuit 80.

[0026] The first terminal 11 and the second terminal 12 are terminals to which a single-phase AC current is inputted from a single-phase AC power supply 20 , and are connected to an AC / DC converter 30 .

[0027] The third terminal 13 is a terminal that is in one of three states: (1) short-circuited with the first terminal 11, (2) short-circuited with the second terminal 12, or (3) open, and is connected to the detection circuit 80. The third terminal 13 may be in a state other than these states. The third terminal 13 may selectively realize these states by, for example, a relay (not shown) connected outside the motor 10.

[0028] The first terminal 11, the second terminal 12, and the third terminal 13 are each made of a conductive material. The first terminal 11, the second terminal 12, and the third terminal 13 may each be made of, for example, a metal connector or a lead wire.

[0029] The AC / DC converter 30 converts the single-phase AC supplied by the single-phase AC power supply 20 into DC. More specifically, the AC / DC converter 30 includes one or more diodes (four diodes in this example) and one or more capacitors (one capacitor in this example), and converts the single-phase AC into DC by rectifying the single-phase AC with the one or more diodes and smoothing the rectified pulsating current with the one or more capacitors.

[0030] The inverter 40 is PWM-controlled by a PWM (Pulse Width Modulation) signal to convert the DC converted by the AC / DC converter 30 into a three-phase AC. More specifically, the inverter 40 includes a plurality of switching elements (six switching elements in this example) that perform switching operations, and these plurality of switching elements are PWM-controlled by a PWM signal output from a control unit 70, which will be described later, to convert the DC converted by the AC / DC converter 30 into a three-phase AC consisting of a U phase, a V phase, and a W phase.

[0031] The windings 50 are supplied with three-phase AC converted by the inverter 40, and generate a magnetic field that rotates the rotor 60. More specifically, the windings 50 include a coil connected to the U phase, a coil connected to the V phase, and a coil connected to the W phase, which are connected to one another in a Y-connection. A magnetic field that rotates the rotor 60 is generated by changing the current flowing through these three coils. The windings 50 may be, for example, a delta-connection.

[0032] The rotor 60 rotates due to the magnetic field generated in the windings 50. The rotor 60 can rotate about the rotation axis in either a first rotation direction or a second rotation direction opposite to the first rotation direction. The rotation speed and rotation direction of the rotor 60 change according to the magnetic field generated in the windings 50. That is, the rotation speed and rotation direction of the rotor 60 change according to the three-phase AC converted by the inverter 40.

[0033] When single-phase AC is input to the first terminal 11 and the second terminal 12, the detection circuit 80 (1) outputs a first detection signal when the third terminal 13 is short-circuited to the first terminal 11, (2) outputs a second detection signal when the third terminal 13 is short-circuited to the second terminal 12, and (3) outputs a third detection signal when the third terminal 13 is in an open state.

[0034] A specific example of the circuit configuration of the detection circuit 80 will be described below with reference to the drawings.

[0035] As shown in FIG. 1, the detection circuit 80 includes a diode 81, a diode 82, an NPN transistor 83 (hereinafter also simply referred to as transistor 83), an NPN transistor 84 (hereinafter also simply referred to as transistor 84), a resistance element 85, a resistance element 86, a resistance element 87, a resistance element 88, a resistance element 89, a resistance element 90, a control power supply 91, a detection signal line 101, and a detection signal line 102.

[0036] The diode 81 has an anode connected to the first terminal 11 and rectifies the single-phase AC input from the single-phase AC power supply 20 to the first terminal 11 .

[0037] Resistance element 85 and resistance element 87 are connected in series between the cathode of diode 81 and the ground, and divide the potential of the cathode of diode 81 .

[0038] The control power supply 91 supplies a potential for pulling up the detection signal line 101 and the detection signal line 102. Here, as an example, the potential is 5 V. The control power supply 91 may include, for example, a DC / DC converter (not shown), and the DC / DC converter may supply a potential by converting the direct current potential converted by the AC / DC converter 30.

[0039] The resistive element 89 is connected to the control power supply 91 and the detection signal line 101, and pulls up the detection signal line 101 to the control potential.

[0040] The transistor 83 has an open collector output, with its base and emitter connected to one terminal and the other terminal, respectively, of the resistor element 87, and its collector connected to the detection signal line 101. The transistor 83 brings the detection signal line 101 and ground into a conductive state when the potential difference between the one terminal and the other terminal of the resistor element 87, i.e., the divided potential of the anode potential of the diode 81, is greater than a threshold value (e.g., 0.6 V), and brings the detection signal line 101 and ground into a non-conductive state when the potential difference is smaller than the threshold value.

[0041] Here, the resistance value of the transistor 83 in the ON state is sufficiently smaller than the resistance value of the resistive element 89. Therefore, when the transistor 83 is in the ON state, the potential of the detection signal line 101 is substantially the ground potential (i.e., substantially 0 V). Therefore, when the transistor 83 is in the OFF state, the potential of the detection signal line 101 is a potential pulled up by the resistive element 89, and when the transistor 83 is in the ON state, the potential is substantially the ground potential.

[0042] Therefore, the potential of the detection signal line 101 becomes high level (i.e., control potential) when the divided potential of the pulsating current rectified by the diode 81 is smaller than the threshold value, and becomes low level (i.e., essentially ground potential) when it is larger than the threshold value.

[0043] 2A is a waveform diagram of a single-phase AC current supplied from the single-phase AC power supply 20. FIG 2B is a waveform diagram of the detection signal line 101.

[0044] As shown in FIG. 2B, the potential of the detection signal line 101 becomes a pulse signal that alternates between high and low levels with the same period as the period of the single-phase AC.

[0045] The diode 82 is an element similar to the diode 81. The diode 82 has an anode connected to the third terminal 13, and (1) when the third terminal 13 is shorted to the first terminal 11, the diode 82 rectifies the single-phase AC input from the single-phase AC power supply 20 to the first terminal 11, and (2) when the third terminal 13 is shorted to the second terminal 12, the diode 82 rectifies the single-phase AC input from the single-phase AC power supply 20 to the second terminal 12.

[0046] Resistance elements 86 and 88 are respectively similar to resistance elements 85 and 87. Resistance elements 86 and 88 are connected in series to the cathode of diode 81, and divide the potential of the cathode of diode 81.

[0047] The resistive element 90 is an element similar to the resistive element 89. The resistive element 90 is connected to a control power supply 91 and a detection signal line 102, and pulls up the detection signal line 102 to a control potential.

[0048] The transistor 84 is an element similar to the transistor 83. The transistor 84 has an open collector output, with the base and emitter connected to one terminal of the resistor element 88 and the other terminal of the resistor element 88, respectively, and the collector connected to the detection signal line 102. The transistor 84 brings the detection signal line 102 into a conductive state and the ground when the potential difference between the one terminal of the resistor element 88 and the other terminal of the resistor element 88, i.e., the divided potential of the anode potential of the diode 82, is greater than a threshold value (e.g., 0.6 V), and brings the detection signal line 102 into a non-conductive state and the ground when the potential difference is smaller than the threshold value.

[0049] Here, the resistance value of the transistor 84 in the ON state is sufficiently smaller than the resistance value of the resistive element 90. Therefore, when the transistor 84 is in the ON state, the potential of the detection signal line 102 is substantially the ground potential (i.e., substantially 0 V). Therefore, the potential of the detection signal line 102 is the control potential when the transistor 84 is in the OFF state, and is substantially the ground potential when the transistor 84 is in the ON state.

[0050] Therefore, the potential of the detection signal line 102 becomes high level (i.e., the control potential) when the divided potential of the pulsating current rectified by the diode 82 is smaller than the threshold value, and becomes low level (i.e., essentially the ground potential) when it is larger than the threshold value.

[0051] When the third terminal 13 is short-circuited to the first terminal 11, the potential of the detection signal line 102 becomes a pulse signal that alternates between high and low levels with the same period as the period of the single-phase AC, similar to the potential of the detection signal line 101. This is because the third terminal 13 is short-circuited to the first terminal 11, and therefore the potential of the cathode of the diode 82 becomes the same potential as the potential of the cathode of the diode 81.

[0052] Therefore, when the third terminal 13 is short-circuited to the first terminal 11, the potential of the detection signal line 102 has the same waveform as the potential of the detection signal line 101. For this reason, Fig. 2B is also a waveform diagram of the detection signal line 102 when the third terminal 13 is short-circuited to the first terminal 11.

[0053] Fig. 3A is a waveform diagram of a single-phase AC current supplied from the single-phase AC power supply 20. Fig. 3B is a waveform diagram of the detection signal line 102 in a state in which the third terminal 13 is short-circuited to the second terminal 12.

[0054] 3B, in a state in which the third terminal 13 is short-circuited to the second terminal 12, the potential of the detection signal line 102 becomes a pulse signal that alternates between high and low levels in the same period as the period of the single-phase AC and is in the opposite phase to the potential of the detection signal line 101. This is because the potential of the cathode of the diode 82 becomes a potential in the opposite phase to the potential of the cathode of the diode 81 because the third terminal 13 is short-circuited to the second terminal 12.

[0055] Fig. 4A is a waveform diagram of a single-phase AC current supplied from the single-phase AC power supply 20. Fig. 4B is a waveform diagram of the detection signal line 102 when the third terminal 13 is in an open state.

[0056] 4B, when the third terminal 13 is in an open state, the potential of the detection signal line 102 remains unchanged at a high level. This is because the third terminal 13 is in an open state. One terminal of the resistor element 88 and the other terminal of the resistor element 88 are both at the ground potential, so that one terminal of the resistor element 88 and the other terminal of the resistor element 88 have the same potential, and the transistor 84 remains unchanged in an off state.

[0057] The detection circuit 80 outputs a first detection signal, a second detection signal, and a third detection signal from two detection signal lines, the detection signal line 101 and the detection signal line 102, with the above configuration. Here, the first detection signal is specifically a pulse signal in which the detection signal line 101 and the detection signal line 102 are in phase with each other and alternate between a high level and a low level with the same period as the period of the single-phase AC. The second detection signal is specifically a pulse signal in which the detection signal line 101 and the detection signal line 102 are in opposite phase with each other and alternate between a high level and a low level with the same period as the period of the single-phase AC. The third detection signal is specifically a signal in which the detection signal line 101 is a pulse signal in which the detection signal line 101 is in phase with each other and alternate between a high level and a low level with the same period as the period of the single-phase AC, and the detection signal line 102 remains at a high level without changing.

[0058] Returning to FIG. 1, the description of the motor 10 will continue.

[0059] The control unit 70 outputs a PWM signal to the inverter 40. More specifically, the control unit 70 outputs the PWM signal so that the rotor 60 is in a first rotation state when the detection circuit 80 outputs a first detection signal, the rotor 60 is in a second rotation state when the detection circuit 80 outputs a second detection signal, and the rotor 60 is in a third rotation state when the detection circuit 80 outputs a third detection signal.

[0060] Here, the first rotation state, the second rotation state, and the third rotation state may be any rotation state of the rotor 60 as long as the rotation states of the rotor 60 are different from each other. For example, the first rotation state may be a state in which the rotor 60 rotates in a first rotation direction at a first rotation speed, the second rotation state may be a state in which the rotor 60 rotates in the first rotation direction at a second rotation speed faster than the first rotation speed, and the third rotation state may be a state in which the rotor 60 rotates in a second rotation direction opposite to the first rotation direction. Also, for example, the first rotation state may be a state in which the rotor 60 rotates in a first rotation direction at a first rotation speed, the second rotation state may be a state in which the rotor 60 rotates in the first rotation direction at a second rotation speed faster than the first rotation speed, and the third rotation state may be a state in which the rotor 60 rotates in the first rotation direction at a third rotation speed faster than the second rotation speed. The control unit 70 may be realized, for example, by a microcomputer (not shown) built into the motor 10 executing a program stored in a memory (not shown) built into the motor 10.

[0061] The storage unit 71 stores PWM information that defines the waveform of the PWM signal output by the control unit 70. That is, the control unit 70 outputs the PWM signal based on the PWM information stored in the storage unit 71. The storage unit 71 may be realized by, for example, a memory (not shown) built into the motor 10.

[0062] The operation receiving unit 73 receives operations from a user who uses the motor drive system 1. The operations received by the operation receiving unit 73 include an operation for updating the PWM signal. The operation receiving unit 73 may be realized by, for example, a touch panel, a keyboard, a switch, or the like. The operation receiving unit 73 may also include, for example, an interface circuit capable of communicating with an external device (for example, a personal computer) and receive a signal from the external device that is generated by the external device and is based on an operation by the user for updating the PWM signal, thereby receiving an operation from the user.

[0063] The update unit 72 updates the PWM signal stored in the storage unit 71 based on an operation from a user accepted by the operation acceptance unit 73. The update unit 72 may be realized, for example, by a microcomputer (not shown) built into the motor 10 executing a program stored in a memory (not shown) built into the motor 10.

[0064] As described above, motor 10 of the present embodiment includes first terminal 11 and second terminal 12 to which single-phase AC is input, third terminal 13, AC / DC converter 30 connected to first terminal 11 and second terminal 12 for converting single-phase AC to DC, inverter 40 for converting DC to three-phase AC by being pulse-width modulated (PWM controlled) using a pulse-width modulated signal (PWM signal), windings 50 to which three-phase AC is supplied, rotor 60 rotates by a magnetic field generated in windings 50, control unit 70 for outputting a PWM signal to the inverter, and detection circuit 80 connected to the third terminal. Detection circuit 80 detects a voltage between first terminal 11 and second terminal 12 and outputs a PWM signal to inverter 40. When single-phase AC is input to terminal 2, (1) a first detection signal is output when the third terminal 13 is shorted to the first terminal 11, (2) a second detection signal is output when the third terminal 13 is shorted to the second terminal 12, and (3) a third detection signal is output when the third terminal 13 is in an open state. The control unit 70 outputs a PWM signal so that the rotor 60 is in the first rotation state when the detection circuit 80 outputs the first detection signal, the rotor 60 is in the second rotation state when the detection circuit 80 outputs the second detection signal, and the rotor 60 is in the third rotation state when the detection circuit 80 outputs the third detection signal.

[0065] This provides a motor that can dynamically switch between three operation modes with mutually different rotation states, and that has one more terminal in addition to a pair of terminals for power supply.

[0066] In addition, the motor 10 further includes a memory unit 71 that stores PWM information that defines the waveform of the PWM signal, an update unit 72 that updates the PWM information, and an operation reception unit 73 that receives operations from a user of the motor 10, and the control unit 70 outputs a PWM signal based on the PWM information, and the update unit 72 updates the PWM information based on operations from the user received by the operation reception unit 73.

[0067] <Consideration> According to the motor 10 configured as above, (1) the rotor 60 is in a first rotation state by shorting the third terminal 13 to the first terminal 11, (2) the rotor 60 is in a second rotation state by shorting the third terminal 13 to the second terminal 12, and (3) the rotor 60 is in a third rotation state by opening the third terminal 13. Thus, according to the motor 10, a motor is provided that can dynamically switch between three operation modes having mutually different rotation states, and that has one terminal (i.e., the third terminal 13) in addition to a pair of terminals for power supply (i.e., the first terminal 11 and the second terminal 12).

[0068] By making the first rotation state, the second rotation state, and the third rotation state include at least a rotation state in which the rotor 60 rotates in a first rotation direction, and a rotation state in which the rotor 60 rotates in a second rotation direction opposite to the first rotation direction, the motor 10 can operate in operating modes in which the rotation directions of the rotor 60 are opposite to each other.

[0069] The motor 10 can operate in an operation mode that is set by an operation received from a user of the motor drive system 1 via an operation reception unit 73 .

[0070] (Embodiment 2) A motor drive system according to a second embodiment, which is configured by partially modifying the motor drive system 1 according to the first embodiment, will be described below.

[0071] In the following, for the motor drive system of embodiment 2, components similar to those of motor drive system 1 of embodiment 1 have already been explained, so they are given the same symbols and their detailed explanations are omitted, and the explanation will focus on the differences from motor drive system 1.

[0072] FIG. 5 is a block diagram showing an example of the configuration of a motor drive system 1A according to the second embodiment.

[0073] As shown in FIG. 5, a motor drive system 1A is configured by changing the motor 10 of the motor drive system 1 of the first embodiment to a motor 10A.

[0074] 5, motor 10A is configured by replacing detection circuit 80 of embodiment 1 with detection circuit 80A of motor 10 of embodiment 1. The following description will focus on detection circuit 80A.

[0075] 5, in the detection circuit 80A, the resistance element 89 according to the first embodiment is changed to a resistance element 89A and a resistance element 89B, the detection signal line 101 according to the first embodiment is changed to a detection signal line 101A, and a diode 92, a diode 93, and a detection signal line 103 are added to the detection circuit 80 according to the first embodiment.

[0076] Resistance element 89A and resistance element 89B are connected in series between control power supply 91 and the ground, and divide the control potential. Here, as an example, the resistance value of resistance element 89A is equal to the resistance value of resistance element 89B. Therefore, the divided potential (hereinafter also referred to as "divided potential") is 2.5V.

[0077] The connection point between the resistance elements 89A and 89B is also connected to the detection signal line 101A. Therefore, the resistance elements 89A and 89B convert the detection signal line 101A into a divided potential.

[0078] Therefore, the potential of the detection signal line 101A becomes a middle level (i.e., the divided potential) when the divided potential of the pulsating current rectified by the diode 81 is smaller than the threshold value, and becomes a low level (i.e., approximately ground potential) when it is larger than the threshold value.

[0079] Fig. 6A is a waveform diagram of a single-phase AC current supplied from the single-phase AC power supply 20. Fig. 6B is a waveform diagram of the detection signal line 101A.

[0080] As shown in FIG. 6B, the potential of the detection signal line 101A becomes a pulse signal that alternates between a middle level and a low level with the same period as the period of the single-phase AC.

[0081] The diode 92 has an anode connected to the detection signal line 101A and a cathode connected to the detection signal line 103. The diode 93 has an anode connected to the detection signal line 102 and a cathode connected to the detection signal line 103. That is, the diodes 92 and 93 are connected in parallel such that their anodes are connected to each other.

[0082] Diodes 92 and 93 connected in parallel in this manner function as a wired-OR circuit that receives detection signal lines 101A and 102 as inputs and outputs detection signal line 103. That is, diodes 92 and 93 output to detection signal line 103 the potential of whichever is not smaller, detection signal line 101A or detection signal line 102.

[0083] As described above in the first embodiment, the potential of the detection signal line 102 when the third terminal 13 is shorted to the first terminal 11 is a pulse signal that alternates between a high level and a low level with the same period as the period of the single-phase AC as shown in FIG. 2B. Therefore, the potential of the detection signal line 103 when the third terminal 13 is shorted to the first terminal 11 is the potential that is not smaller than the pulse signal that alternates between a middle level and a low level with the same period as the period of the single-phase AC as shown in FIG. 6B and the pulse signal that alternates between a high level and a low level with the same period as the period of the single-phase AC as shown in FIG. 2B. Therefore, the potential of the detection signal line 103 when the third terminal 13 is shorted to the first terminal 11 is a pulse signal that alternates between a high level and a low level with the same period as the period of the single-phase AC as shown in FIG. 2B. Therefore, FIG. 2B is also a waveform diagram of the detection signal line 102 in a state in which the third terminal 13 is short-circuited to the first terminal 11 in the second embodiment.

[0084] As described above in the first embodiment, the potential of the detection signal line 102 in the state where the third terminal 13 is short-circuited to the second terminal 12 is a pulse signal shown in Fig. 3B that alternates between a high level and a low level in the same period as the period of the single-phase AC and is in the opposite phase to the potential of the detection signal line 101A. Therefore, the potential of the detection signal line 103 in the state where the third terminal 13 is short-circuited to the second terminal 12 is the larger of the pulse signal shown in Fig. 6B that alternates between a middle level and a low level in the same period as the period of the single-phase AC and the pulse signal shown in Fig. 3B that alternates between a high level and a low level in the same period as the period of the single-phase AC and is in the opposite phase to the potential of the detection signal line 101A. Therefore, the potential of the detection signal line 103 in the state where the third terminal 13 is short-circuited to the first terminal 11 is a pulse signal that alternates between a high level and a middle level in the same period as the period of the single-phase AC and is in the opposite phase to the potential of the detection signal line 101A.

[0085] Fig. 7A is a waveform diagram of a single-phase AC current supplied from the single-phase AC power supply 20. Fig. 7B is a waveform diagram of the detection signal line 103 in a state in which the third terminal 13 is short-circuited to the second terminal 12.

[0086] As described above in the first embodiment, when the third terminal 13 is in an open state, the potential of the detection signal line 102 becomes a signal that remains unchanged at a high level as shown in FIG. 4B. Therefore, the potential of the detection signal line 103 when the third terminal 13 is in an open state becomes the smaller of a pulse signal that alternates between a middle level and a low level with the same period as the period of the single-phase AC as shown in FIG. 6B, and a signal that remains unchanged at a high level as shown in FIG. 4B. Therefore, the potential of the detection signal line 103 when the third terminal 13 is in an open state becomes a signal that remains unchanged at a high level as shown in FIG. 4B. Therefore, FIG. 4B is also a waveform diagram of the detection signal line 103 when the third terminal 13 is in an open state in the second embodiment.

[0087] The detection circuit 80A, with the above configuration, outputs a first detection signal, a second detection signal, and a third detection signal from one detection signal line 103. Here, the first detection signal is specifically a pulse signal that alternates between a high level and a low level with the same period as the period of the single-phase AC. The second detection signal is specifically a pulse signal that is in the opposite phase to the first detection signal and alternates between a high level and a middle level with the same period as the period of the single-phase AC. Also, the third detection signal is specifically a signal that the detection signal line 103 does not change and remains at a high level.

[0088] <Consideration> According to the motor 10A having the above configuration, like the motor 10 according to embodiment 1, a motor is provided that is capable of dynamically switching between three operating modes having mutually different rotational states, and that has one terminal in addition to a pair of terminals for power supply.

[0089] Like the motor 10 according to the first embodiment, the motor 10A can operate in an operation mode in which the rotation directions of the rotors 60 are opposite to each other.

[0090] Like the motor 10 according to the first embodiment, the motor 10A can operate in an operation mode set by an operation received by the operation reception unit 73 from a user who uses the motor drive system 1A.

[0091] (Embodiment 3) Hereinafter, a motor drive system according to a third embodiment will be described, which is configured by partially modifying the motor drive system 1 according to the first embodiment.

[0092] In the following, for the motor drive system of embodiment 3, components similar to those of motor drive system 1 of embodiment 1 have already been explained, so they are given the same reference numerals and their detailed explanation is omitted, and the explanation will focus on the differences from motor drive system 1.

[0093] FIG. 8 is a block diagram showing an example of the configuration of a motor drive system 1B according to the third embodiment.

[0094] As shown in FIG. 8, a motor drive system 1B is configured by changing the motor 10 according to embodiment 1 to a motor 10B, in comparison with the motor drive system 1 according to embodiment 1.

[0095] 8, motor 10B is configured by replacing detection circuit 80 of motor 10 of embodiment 1 with detection circuit 80B. The following description will focus on detection circuit 80B.

[0096] As shown in FIG. 8, the detection circuit 80B includes a control power supply 91, a diode 111, a diode 112, a diode 113, a diode 114, a resistive element 115, a resistive element 116, a resistive element 117, and a detection signal line 120.

[0097] The diode 111 has an anode connected to the first terminal 11 and rectifies the single-phase AC input from the single-phase AC power supply 20 to the first terminal 11 .

[0098] The diode 112 is an element similar to the diode 111. The diode 112 has an anode connected to the third terminal 13, and (1) when the third terminal 13 is shorted to the first terminal 11, the diode 112 rectifies the single-phase AC input from the single-phase AC power supply 20 to the first terminal 11, and (2) when the third terminal 13 is shorted to the second terminal 12, the diode 112 rectifies the single-phase AC input from the single-phase AC power supply 20 to the second terminal 12.

[0099] The resistive element 115 has one terminal connected to the cathode of the diode 111 and the other terminal connected to the detection signal line 120 .

[0100] The resistive element 116 is an element similar to the resistive element 115. The resistive element 116 has one terminal connected to the cathode of the diode 112 and the other terminal connected to the detection signal line 120. That is, the resistive element 115 and the resistive element 116 are connected in parallel such that the other terminals of the resistive element 115 and the resistive element 116 are connected to each other.

[0101] The resistor element 117 has one terminal connected to the detection signal line 120 and the other terminal connected to the ground. That is, the resistor element 115 and the resistor element 117 are connected in series between the cathode of the diode 111 and the ground. Therefore, the resistor element 115 and the resistor element 117 divide the potential of the cathode of the diode 111. The resistor element 116 and the resistor element 117 are connected in series between the cathode of the diode 112 and the ground. Therefore, the resistor element 116 and the resistor element 117 divide the potential of the cathode of the diode 112. Therefore, the potential of the detection signal line 120 becomes a potential obtained by superposing (1) the potential of the cathode of the diode 111 divided by the resistor element 115 and the resistor element 117, and (2) the potential of the cathode of the diode 112 divided by the resistor element 116 and the resistor element 117.

[0102] Fig. 9A is a waveform diagram of a single-phase AC current supplied from the single-phase AC power supply 20. Fig. 9B is a waveform diagram of the detection signal line 120 when the third terminal 13 is in an open state.

[0103] When the third terminal 13 is in an open state, the potential of the detection signal line 120 becomes the potential of the cathode of the diode 111 itself, which is divided by the resistance element 115 and the resistance element 117 .

[0104] 9, when the third terminal 13 is open, the potential of the detection signal line 120 is a potential obtained by dividing the potential of the pulsating current half-wave rectified by the diode 111 by the resistor elements 115 and 117. That is, when the third terminal 13 is open, the signal of the detection signal line 120 is a pulsating current that pulsates with the same period as the single-phase AC.

[0105] Fig. 10A is a waveform diagram of a single-phase AC supplied from the single-phase AC power supply 20. Fig. 10B is a waveform diagram of the detection signal line 120 in a state in which the third terminal 13 is short-circuited to the first terminal 11.

[0106] In a state in which the third terminal 13 is short-circuited to the first terminal 11, both the diode 111 and the diode 112 rectify the single-phase AC input from the single-phase AC power supply 20 to the first terminal 11. Therefore, the pulsating current half-wave rectified by the diode 111 and the pulsating current half-wave rectified by the diode 112 are in phase with each other.

[0107] 10A and 10B, the potential of the detection signal line 120 is a potential obtained by superposing, in phase, (1) a potential obtained by dividing the potential of the pulsating current half-wave rectified by the diode 111 by the resistor elements 115 and 117, and (2) a potential obtained by dividing the potential of the pulsating current half-wave rectified by the diode 112 by the resistor elements 116 and 117. That is, when the third terminal 13 is connected to the first terminal 11, the signal of the detection signal line 120 is a pulsating current that pulsates with the same period as the single-phase AC.

[0108] As shown in Figures 9A, 9B, 10A, and 10B, the peak potential of the detection signal line 120 when the third terminal 13 is shorted to the first terminal 11 (hereinafter also referred to as the "high peak potential") is higher than the peak potential of the detection signal line 120 when the third terminal 13 is in the open state (hereinafter also referred to as the "middle peak potential").

[0109] In a state in which the third terminal 13 is short-circuited to the second terminal 12, the diode 111 rectifies the single-phase AC input from the single-phase AC power supply 20 to the first terminal 11. Then, the diode 112 rectifies the single-phase AC input from the single-phase AC power supply 20 to the second terminal 12. Therefore, the pulsating current half-wave rectified by the diode 111 and the pulsating current half-wave rectified by the diode 112 are in opposite phases to each other.

[0110] Therefore, in a state where the third terminal 13 is short-circuited to the second terminal 12, the potential of the detection signal line 120 is a potential obtained by superposing, in opposite phases, (1) a potential obtained by dividing the potential of the pulsating current half-wave rectified by the diode 111 by the resistor elements 115 and 117, and (2) a potential obtained by dividing the potential of the pulsating current half-wave rectified by the diode 112 by the resistor elements 116 and 117, as shown in Figs. 11A and 11B. Fig. 11A is a waveform diagram of a single-phase AC current supplied from the single-phase AC power source 20. Fig. 11B is a waveform diagram of the detection signal line 120. That is, the signal of the detection signal line 120 in a state where the third terminal 13 is connected to the second terminal 12 is a pulsating current pulsating at a period twice that of the single-phase AC current.

[0111] The detection circuit 80B, with the above configuration, outputs a first detection signal, a second detection signal, and a third detection signal from one detection signal line 120. Here, the first detection signal is specifically a pulsating signal that pulsates with the same period as the period of the single-phase AC and has a high peak potential. The second detection signal is specifically a pulsating signal that pulsates with a period twice as long as the period of the single-phase AC. The third detection signal is specifically a pulsating signal that pulsates with the same period as the period of the single-phase AC and has a middle peak potential.

[0112] <Consideration> According to the motor 10B having the above configuration, like the motor 10 of embodiment 1, a motor is provided that is capable of dynamically switching between three operating modes having mutually different rotational states, and that has one more terminal in addition to a pair of terminals for power supply.

[0113] Like motor 10 according to the first embodiment, motor 10B can operate in an operation mode in which the rotation directions of rotors 60 are opposite to each other.

[0114] Like motor 10 according to the first embodiment, motor 10B can operate in an operation mode set by an operation received by operation reception unit 73 from a user using motor drive system 1B.

[0115] (Other embodiments) Although the motor drive device according to one aspect of the present disclosure has been described above based on the first, second, and third embodiments, the present disclosure is not limited to these embodiments. As long as it does not deviate from the spirit of the present disclosure, various modifications conceivable by a person skilled in the art to these embodiments, or configurations constructed by combining components in different embodiments, are also included within the scope of one or more aspects of the present disclosure. [Industrial Applicability]

[0116] The present disclosure is widely applicable to motors. [Explanation of symbols]

[0117] 1, 1A, 1B Motor Drive System 10, 10A, 10B motor 20 Single-phase AC power supply 11 First Terminal 12 Second Terminal 13 Third Terminal 30 AC / DC converter 40 Inverter 50 Windings 60 Rotor 70 Control section 71 Storage section 72 Update section 73 Operation reception section 80, 80A, 80B Detection circuit 81, 82, 92, 93, 111, 112, 113, 114 Diodes 83, 84 NPN transistor (transistor) 85, 86, 87, 88, 89, 89A, 89B, 90, 115, 116, 117 Resistance elements 91 Control power supply 101, 101A, 102, 103, 120 Detection signal line

Claims

1. a first terminal and a second terminal to which a single-phase AC current is input; A third terminal; and an AC / DC converter connected to the first terminal and the second terminal for converting the single-phase AC into a DC; an inverter that converts the direct current into a three-phase alternating current by being pulse-width modulated by a pulse-width modulated signal; a winding to which the three-phase AC is supplied; a rotor that rotates due to a magnetic field generated in the winding; a control unit that outputs the pulse width modulated signal to the inverter; a detection circuit connected to the third terminal; the detection circuit, in a state in which the single-phase AC is input to the first terminal and the second terminal, (1) outputs a first detection signal when the third terminal is short-circuited to the first terminal, (2) outputs a second detection signal when the third terminal is short-circuited to the second terminal, and (3) outputs a third detection signal when the third terminal is in an open state; The control unit outputs the pulse width modulated signal so that the rotor is in a first rotation state when the detection circuit outputs the first detection signal, so that the rotor is in a second rotation state when the detection circuit outputs the second detection signal, and so that the rotor is in a third rotation state when the detection circuit outputs the third detection signal, and the first rotation state, the second rotation state, and the third rotation state are mutually different rotation states of the rotor.

2. 2. The motor according to claim 1, wherein the first rotation state, the second rotation state, and the third rotation state include at least a rotation state in which the rotor rotates in a first rotation direction, and a rotation state in which the rotor rotates in a second rotation direction opposite to the first rotation direction.

3. the first rotation state is a state in which the rotor rotates in a first rotation direction at a first rotation speed; the second rotation state is a state in which the rotor rotates in the first rotation direction at a second rotation speed that is faster than the first rotation speed, The third rotation state is a state in which the rotor rotates in a second rotation direction opposite to the first rotation direction. The motor according to claim 1 .

4. a memory unit that stores pulse width modulation information that defines a waveform of the pulse width modulation signal; an update unit that updates the pulse width modulation information; an operation receiving unit that receives an operation of the motor from a user, 3. The motor according to claim 1, wherein the control unit outputs the pulse width modulation signal based on the pulse width modulation information, and the update unit updates the pulse width modulation information based on an operation from the user accepted by the operation acceptance unit.

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