Control circuit, control method, and pump

Abstract

This provides a new control circuit capable of preventing abnormal operation of microcontrollers. This circuit 8 is a control circuit used in the pump 1, which is driven by a control voltage V1 supplied from the inverter I. This circuit 8 comprises a voltage generation unit 81, a microcontroller 82, and a monitoring unit 83. The voltage generation unit generates the microcontroller drive voltage V2 of the microcontroller based on the control voltage. The monitoring unit monitors the microcontroller drive voltage. The monitoring unit resets the microcontroller when the microcontroller drive voltage is less than the microcontroller operating voltage V3 of the microcontroller.

Description

Technical Field

[0001] The present invention relates to a control circuit, a control method, and a pump.

Background Art

[0002] The voltage required for the operation of an electric circuit (for example, a control circuit) is generally supplied from a switchboard connected to a commercial power supply to the control circuit via a power supply board (for example, see Patent Document 1).

[0003] Here, for example, when the control circuit is a control circuit of a device (for example, a bearing wear monitoring device) that can be attached to a pump, generally, individual (two systems) wirings are required for each of the pump and the control circuit. In this case, connection work to the switchboard for each system is required, and a plurality of terminals of the switchboard are also occupied by the number of systems. Therefore, reduction of wiring is desired. By branching one system of wiring to the pump and the control circuit, reduction of wiring can be achieved.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, the operation of the pump (e.g., the rotation of the motor) can be controlled by an inverter. In this case, the inverter converts voltage and frequency at a predetermined ratio for the time it takes for the output voltage / output frequency to change from 0V / 0Hz to the rated voltage / rated frequency (e.g., 200V / 50Hz) (hereinafter referred to as the "acceleration time"). The converted voltage is supplied from the inverter to the pump (motor) and the control circuit at the converted frequency. The transformer in the control circuit steps down the supplied voltage at a predetermined ratio and supplies it to the microcontroller in the control circuit. Therefore, in order for the voltage supplied to the transformer to become the operating voltage of the microcontroller, an acceleration time equal to the acceleration time of the inverter is required. Consequently, before the acceleration time has elapsed, a voltage lower than the operating voltage of the microcontroller is supplied to the microcontroller. At this time, the microcontroller may malfunction.

[0006] One possible method to prevent abnormal operation of a microcontroller is to connect (integrate) a delay circuit to the microcontroller. In this case, the delay time of the delay circuit is set to the same time as the acceleration time, so that voltages below the microcontroller's operating voltage are not supplied to the microcontroller. However, the acceleration time can be set as appropriate by the user, and changing the acceleration time also involves changing the delay time. Therefore, the user's setting burden increases. Also, if the acceleration time is set to be short, the motor rotates at high speed for a short time, which can increase the load on the motor.

[0007] The present invention aims to provide a novel control circuit capable of preventing abnormal operation of a microcontroller. [Means for solving the problem]

[0008] In one embodiment of the present invention, the control circuit is a pump driven by a drive voltage supplied from an inverter. The bearing wear monitoring device that is equipped with A control circuit comprising a microcontroller, a voltage generation unit that generates a microcontroller drive voltage for the microcontroller based on the drive voltage, and a monitoring unit that monitors the microcontroller drive voltage, wherein the monitoring unit resets the microcontroller when the microcontroller drive voltage is less than the microcontroller operating voltage of the microcontroller.

[0009] A control method in one embodiment of the present invention involves a pump driven by a drive voltage supplied from an inverter. The bearing wear monitoring device that is equipped with A control method performed by a control circuit, the control circuit comprising a microcontroller, a voltage generation unit that generates a microcontroller drive voltage for the microcontroller based on the drive voltage, and a monitoring unit that monitors the microcontroller drive voltage, wherein the control method includes a reset step in which the control circuit resets the microcontroller when the microcontroller drive voltage is less than the microcontroller operating voltage for the microcontroller.

[0010] A pump in one embodiment of the present invention is a pump driven by a drive voltage supplied from an inverter, comprising a motor unit to which the drive voltage is supplied, Bearing wear monitoring device for monitoring the condition of the motor section The motor unit comprises a rotor, a stator that rotates the rotor, a rotating shaft that rotates together with the rotor, and a bearing that supports the rotating shaft. The bearing wear monitoring device The wear condition of the bearing is monitored. And, as mentioned above Control circuit , equipped . [Effects of the Invention]

[0011] This invention provides a novel control circuit capable of preventing abnormal operation of a microcontroller. [Brief explanation of the drawing]

[0012] [Figure 1] This is a side view of an embodiment of the pump according to the present invention. [Figure 2] This is a schematic cross-sectional view showing the longitudinal section of the motor part of the pump described above. [Figure 3] This is a functional block diagram of the monitoring device for the pump mentioned above. [Figure 4] This is a schematic perspective view showing the arrangement of the detection coils in the above-mentioned monitoring device. [Figure 5] This graph shows the relationship between the voltage and frequency supplied to the pump and monitoring device mentioned above. [Figure 6]It is a graph showing the relationship between the voltage and frequency supplied to the microcomputer and the monitoring unit of the control circuit according to the present invention. [Figure 7] It is a flowchart showing an example of the operation of the above control circuit. [Figure 8] It is a flowchart showing an example of the first reset process included in the above operation. [Figure 9] It is a flowchart showing an example of the second reset process included in the above operation.

Embodiments for Carrying Out the Invention

[0013] Embodiments of a control circuit (hereinafter referred to as "this circuit"), a control method (hereinafter referred to as "this method"), and a pump (hereinafter referred to as "this pump") according to the present invention will be described below with reference to the drawings. In each figure, the same members and elements are denoted by the same reference numerals, and redundant explanations are omitted. Also, the dimensional ratios of the respective elements may be exaggerated for the sake of explanation and are not limited to the ratios shown in each drawing.

[0014] In the following description, as an example of this pump, a canned motor pump will be described. Also, as an example of this circuit, a control circuit of a bearing wear monitoring device (hereinafter referred to as "monitoring device") attached to the canned motor pump will be described. The monitoring device monitors the wear state of the bearing of the canned motor pump. This circuit controls the operation of the monitoring device.

[0015] ●Pump● ●Configuration of the pump First, the configuration of this pump will be described below.

[0016] FIG. 1 is a side view of this pump showing an embodiment of this pump. For the sake of explanation, the upper half of this pump 1 is shown as a cross-sectional view in this figure.

[0017] Pump 1 is a canned motor pump used for transporting liquids (e.g., high-temperature liquids). Pump 1 comprises a pump unit 2, a motor unit 3, an adapter 4, and a monitoring device 5.

[0018] The configurations of the pump unit 2, motor unit 3, and adapter 4 of this pump 1 are common to those of a known canned motor pump. Therefore, in the following description, only an overview of the configurations of the pump unit 2, motor unit 3, and adapter 4 will be described, and a detailed explanation of these configurations will be omitted.

[0019] In the following explanation, "front direction" refers to the direction in which the pump unit 2 is located relative to the motor unit 3 (forward direction), and "rear direction" refers to the direction in which the motor unit 3 is located relative to the pump unit 2 (rear direction).

[0020] Pump unit 2 draws in and discharges the liquid being handled. Pump unit 2 comprises a pump housing 20, an impeller 21, a pump chamber 22, a suction pipe section 23, and a discharge pipe section 24. The pump housing 20 consists of a pump chamber 22 housing the impeller 21, a suction pipe section 23 which is the path for the liquid being handled drawn into the pump chamber 22, and a discharge pipe section 24 which is the path for the liquid being handled discharged from the pump chamber 22. The pump chamber 22 is in communication with the suction pipe section 23 and the discharge pipe section 24.

[0021] The motor unit 3 operates at a predetermined drive voltage and drive frequency (for example, 200V / 50Hz; hereinafter referred to as "motor drive voltage and drive frequency") to rotate the impeller 21. The motor unit 3 comprises a motor housing 30, a rotating shaft 31, two bearings 32 and 33, a rotor 34, a stator 35, a can 36, and terminal terminals 37.

[0022] Figure 2 is a schematic cross-sectional view showing the longitudinal section of the motor unit 3. In the following description, Figure 1 will be referred to together with Figure 2 as appropriate.

[0023] The motor housing 30 contains the stator 35 and the can 36 in a liquid-tight manner.

[0024] The rotating shaft 31 rotates due to the rotation of the rotor 34, transmitting rotational power to the impeller 21. The rotating shaft 31 is cylindrical in shape. The rotating shaft 31 is inserted into the rotor 34 and fixed to the rotor 34. The front end of the rotating shaft 31 protrudes into the pump chamber 22, and the impeller 21 is attached to this end.

[0025] In the following explanation, "thrust direction" refers to the axial direction of the rotation axis 31, "radial direction" refers to the radial direction of the rotation axis 31, and "circumferential direction" refers to the circumferential direction of the rotation axis 31.

[0026] Bearing 32 is positioned in the front direction of the rotor 34 and rotatably supports the rotating shaft 31. Bearing 33 is positioned in the rear direction of the rotor 34 and rotatably supports the rotating shaft 31. Bearings 32 and 33 are, for example, sliding bearings.

[0027] The rotor 34 rotates due to the rotating magnetic field generated by the stator 35. The rotor 34 has a cylindrical shape.

[0028] The stator 35 generates a rotating magnetic field that rotates the rotor 34. The stator 35 is roughly cylindrical in shape. The stator 35 is connected to the inverter I (described later; see Figure 3) via terminal 37.

[0029] The can 36 liquid-tightly houses the rotating shaft 31, bearings 32 and 33, and rotor 34. The can 36 is cylindrical in shape. A portion of the handling fluid introduced from the suction pipe section 23 is introduced into the can 36 and used to cool the bearings 32 and 33 and the motor section 3, and is then discharged into the discharge pipe section 24.

[0030] The adapter 4 is connected to the rear end of the pump unit 2 and the front end of the motor unit 3, thus connecting the pump unit 2 and the motor unit 3.

[0031] ● Configuration of the monitoring device Next, the configuration of the monitoring device 5 is described below.

[0032] Figure 3 is a functional block diagram of the monitoring device 5. The diagram shows the flow of voltage (control voltage V1 (described later) and microcontroller drive voltage V2 (described later)) with black arrows. The diagram also shows the flow of signal (detection signal DS (described later)) with white arrows.

[0033] The monitoring device 5 is a bearing wear monitoring device that monitors the wear state of bearings 32 and 33 by detecting changes in magnetic flux corresponding to changes in the mechanical position of the rotor 34 relative to the stator 35. The monitoring device 5 comprises eight detection coils C1, C2, C3, C4, C5, C6, C7, C8, a storage unit 6, a display unit 7, and the main circuit 8.

[0034] The configurations of the detection coils C1-C8, the storage unit 6, and the display unit 7 of the monitoring device 5 are common to those of a known bearing wear monitoring device. Therefore, in the following description, only an outline of the configurations of the detection coils C1-C8, the storage unit 6, and the display unit 7 will be described, and a detailed description of these configurations will be omitted.

[0035] Figure 4 is a schematic perspective view showing the arrangement of detection coils C1 to C8. This figure shows that detection coils C1 to C4 are mounted at equal intervals on the front end of the stator 35 in the circumferential direction. This figure also shows that detection coils C5 to C8 are mounted at equal intervals on the rear end of the stator 35 in the circumferential direction. In the following description, Figure 3 will be referred to as appropriate along with Figure 4.

[0036] Detection coils C1 to C8 detect changes in magnetic flux corresponding to changes in the position (displacement) of the rotor 34 relative to the stator 35, and generate and output detection signals DS indicating the change in magnetic flux. The rotor 34 is displaced radially with the rotating shaft 31 according to the amount of radial wear of the bearings 32 and 33, and is displaced thrust with the rotating shaft 31 according to the amount of thrust wear of the bearings 32 and 33. In other words, the amount of displacement of the rotor 34 can be considered as the amount of wear of the bearings 32 and 33. Therefore, the monitoring device 5 calculates the amount of wear of the bearings 32 and 33 in the radial and thrust directions based on the detection signals DS from the detection coils C1 to C8 using a known calculation method.

[0037] The storage unit 6 stores information necessary for the operation of the monitoring device 5 (for example, the amount of wear of bearings 32 and 33 in the radial and thrust directions calculated by the monitoring device 5). The storage unit 6 is a non-volatile memory such as EEPROM (Electrically Erasable Programmable Read-Only Memory) or flash memory.

[0038] The display unit 7 displays the amount of wear on bearings 32 and 33 in the radial and thrust directions. The display unit 7 is composed of, for example, multiple LEDs (light-emitting diodes) that display the amount of wear.

[0039] This circuit 8 controls the operation of the entire monitoring device 5. Based on the detection signals DS from detection coils C1 to C8, this circuit 8 (monitoring device 5) calculates the wear amount of bearings 32 and 33 in the radial and thrust directions using a known calculation method. This circuit 8 displays the calculated wear status of bearings 32 and 33 in the radial and thrust directions on the display unit 7. The specific configuration of this circuit 8 will be described later.

[0040] ●Control circuit● ●Control circuit configuration Next, the configuration of this circuit 8 will be described below.

[0041] This circuit 8 includes a connection unit 80, a voltage generation unit 81, a microcontroller 82, and a monitoring unit 83.

[0042] The connection section 80 is the interface to which the detection coils C1 to C8 and the pump 1 are connected.

[0043] Inverter I controls the voltage and frequency of power supplied from an external power source PS (e.g., commercial power source) based on a known Vf pattern, changing the voltage and frequency from an initial voltage and initial frequency (e.g., 0V / 0Hz) to a motor drive voltage and motor drive frequency (e.g., 200V / 50Hz). Inverter I supplies the control voltage V1 to the pump 1 (motor unit 3) and the monitoring device 5 (circuit 8). Specifically, for example, inverter I supplies the control voltage V1 to the pump 1 (motor unit 3). The pump 1 (motor unit 3) supplies the supplied control voltage V1 to the monitoring device 5 (circuit 8). That is, inverter I supplies the control voltage V1 to the monitoring device 5 (circuit 8) via the pump 1 (motor unit 3). "Control voltage V1" is the voltage output from inverter I by control based on the Vf pattern (Vf control) performed by inverter I. Control voltage V1 is an example of a drive voltage in the present invention.

[0044] The voltage generation unit 81 is, for example, a known transformer. The voltage generation unit 81 generates a microcontroller drive voltage V2 based on the control voltage V1 supplied from the inverter I. Specifically, for example, the voltage generation unit 81 reduces the control voltage V1 supplied from the inverter I by a predetermined ratio to generate the microcontroller drive voltage V2. The voltage generation unit 81 supplies the microcontroller drive voltage V2 to the microcontroller 82 and the monitoring unit 83. The "microcontroller drive voltage V2" is the voltage generated by the voltage generation unit 81 by reducing the control voltage V1 by a predetermined ratio. Details of the relationship between the control voltage V1 and the microcontroller drive voltage V2 will be described later.

[0045] The microcontroller 82 controls the operation of the entire monitoring device 5. The microcontroller 82 is a microcomputer that includes, for example, a processor such as a CPU (Central Processing Unit) 82a, volatile memory such as RAM (Random Access Memory) 82b which functions as a workspace for the CPU 82a, non-volatile memory such as ROM (Read Only Memory) 82c which stores various information such as a known control program P1 and a BIOS (Basic Input Output System) program P2 that control the operation of the monitoring device 5, and an A / D converter 820. The CPU 82a functions as a display control unit 821. In other words, the microcontroller 82 also includes a display control unit 821.

[0046] The "BIOS program P2" is the first program (firmware) that the CPU 82a loads when the microcontroller drive voltage V2 is supplied to the microcontroller 82 (when the microcontroller 82 starts up). In other words, the CPU 82a loads the BIOS program P2 before loading the control program P1. The microcontroller 82 (CPU 82a) runs the BIOS program P2 to initialize the hardware resources of the monitoring device 5 (for example, the CPU 82a, RAM 82b, ROM 82c, memory unit 6, display unit 7, etc.).

[0047] In the microcontroller 82 (CPU 82a), the control program P1 is executed, and the control program P1 works in cooperation with the hardware resources of the monitoring device 5 to realize a method for calculating the wear amount of bearings 32 and 33 in the radial and thrust directions. Furthermore, by having the processor (CPU 82a) of the microcontroller 82 execute the control program P1, the control program P1 makes the processor function as the control unit of a known bearing wear monitoring device, and causes the processor to execute the calculation method.

[0048] The A / D converter 820 converts analog signals input from a known signal processing circuit (not shown) that processes signals based on detection signals DS from detection coils C1 to C8 into digital signals.

[0049] The display control unit 821 displays the calculated wear amounts of bearings 32 and 33 in the radial and thrust directions on the display unit 7. In other words, the display control unit 821 controls the display on the display unit 7 based on the calculated wear amounts of bearings 32 and 33 in the radial and thrust directions.

[0050] The monitoring unit 83 is a known reset IC that monitors the microcontroller drive voltage V2. Based on the microcontroller drive voltage V2 supplied from the voltage generation unit 81, the monitoring unit 83 causes the microcontroller 82 to reset. Details of the reset of the microcontroller 82 will be described later.

[0051] ● Relationship between control voltage and microcontroller drive voltage Next, the relationship between the control voltage V1 and the microcontroller drive voltage V2 is explained below.

[0052] Figure 5 is a graph showing the relationship between the voltage (control voltage V1) supplied (output) from the inverter I to the pump 1 (motor section 3) and the monitoring device 5 (circuit 8) and the frequency. The figure shows a state where the ratio of voltage to frequency remains constant (for example, 4:1) as the voltage and frequency change (increase) over time from 0V / 0Hz to 200V / 50Hz.

[0053] As mentioned above, the control voltage V1 is the voltage output from inverter I by control based on the Vf pattern (Vf control) performed by inverter I. The range of the control voltage V1 is, for example, 0V to 200V. The frequency range corresponding to the control voltage V1 is, for example, 0Hz to 50Hz. As shown in Figure 5, the control voltage V1 / frequency is, for example, 20V / 5Hz, 132V / 33Hz, and 200V / 50Hz.

[0054] Figure 6 is a graph showing the relationship between the voltage (microcontroller drive voltage V2) supplied (output) from the voltage generation unit 81 to the microcontroller 82 and the monitoring unit 83, and the frequency. The figure shows a state where the ratio of voltage (microcontroller drive voltage V2) to frequency remains constant (for example, 1:10) while the voltage and frequency change (increase) over time from 0V / 0Hz to 5V / 50Hz.

[0055] As described above, the voltage generation unit 81 generates the microcontroller drive voltage V2 by stepping down the control voltage V1 at a predetermined ratio (for example, output voltage / input voltage = 1 / 40). That is, for example, the voltage generation unit 81 steps down 200V to 5V (microcontroller operating voltage V3 (described later)), steps down 132V to 3.3V (monitoring unit operating voltage V4 (described later)), and steps down 20V to 0.5V (abnormal signal generation voltage V5 (described later)). In other words, the range of the microcontroller drive voltage V2 is, for example, 0V to 5V. The frequency range corresponding to the microcontroller drive voltage V2 is, for example, 0Hz to 50Hz. As shown in Figure 6, the microcontroller drive voltage V2 / frequency is, for example, 0.5V / 5Hz, 3.3V / 33Hz, and 5V / 50Hz.

[0056] ● Microcontroller reset Next, the details of resetting the microcontroller 82 are described below. Figures 3 and 6 will be referenced as appropriate in the following description.

[0057] In the following description, the monitoring unit 83 is supplied with a microcontroller drive voltage V2. The operation of the monitoring unit 83 changes depending on the magnitude of the microcontroller drive voltage V2.

[0058] As described above, the monitoring unit 83 resets the microcontroller 82 based on the microcontroller drive voltage V2 supplied from the voltage generation unit 81.

[0059] Here, the microcontroller operating voltage V3 of the microcontroller 82 is, for example, 5V. The monitoring unit operating voltage V4 of the monitoring unit 83 is, for example, 3.3V. The abnormal signal generation voltage V5 of the monitoring unit 83 is, for example, 0.5V. That is, the monitoring unit operating voltage V4 is less than the microcontroller operating voltage V3, and the abnormal signal generation voltage V5 is less than the monitoring unit operating voltage V4. The "microcontroller operating voltage V3" is the voltage required for the microcontroller 82 to operate normally (for example, the execution of the control program P1 by the CPU 82a). The "monitoring unit operating voltage V4" is the voltage required for the monitoring unit 83 to operate normally (for example, monitoring the microcontroller drive voltage V2 and generating the reset signal S2). The "abnormal signal generation voltage V5" is the voltage required for the monitoring unit 83 to generate the abnormal signal S1.

[0060] When the microcontroller drive voltage V2 is greater than or equal to the abnormal signal generation voltage V5 and less than the monitoring unit operating voltage V4, the monitoring unit 83 generates an abnormal signal S1 indicating that the microcontroller drive voltage V2 is less than the monitoring unit operating voltage V4. The monitoring unit 83 transmits the generated abnormal signal S1 to the microcontroller 82 as a reset signal S2 (described later). The microcontroller 82 receives the abnormal signal S1 and resets itself.

[0061] Here, the monitoring unit 83 continuously transmits an abnormal signal S1 to the microcontroller 82 until the microcontroller drive voltage V2 becomes the monitoring unit operating voltage V4.

[0062] When the microcontroller drive voltage V2 is greater than or equal to the monitoring unit operating voltage V4 and less than the microcontroller operating voltage V3, the monitoring unit 83 generates a reset signal S2 to reset the microcontroller 82. The monitoring unit 83 transmits the generated reset signal S2 to the microcontroller 82. The microcontroller 82 receives the reset signal S2 and resets itself.

[0063] Here, the monitoring unit 83 intermittently sends a reset signal S2 to the microcontroller 82 until the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3. In other words, the period during which the monitoring unit 83 sends the reset signal S2 is from after the startup of the microcontroller 82 until before the start of the abnormal operation of the microcontroller 82. Details of the abnormal operation of the microcontroller 82 will be described later.

[0064] In this invention, the monitoring unit 83 may continuously transmit a reset signal S2 to the microcontroller 82 until the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3.

[0065] ● Microcontroller malfunction Next, the details of the abnormal operation of microcontroller 82 are explained below.

[0066] When a microcontroller drive voltage V2, which is less than the microcontroller operating voltage V3, is supplied to the microcontroller 82, the microcontroller 82 may malfunction. In this case, the CPU 82a may not be able to correctly execute the control program P1. Examples of malfunctions of the microcontroller 82 include: "The CPU 82a may not correctly acquire (read) the various information stored in the ROM 82c," "The wear amount of bearings 32 and 33 may not be calculated correctly," and "The wear amount of bearings 32 and 33 may not be displayed correctly on the display unit 7." In other words, when the microcontroller 82 malfunctions, the monitoring device 5 may not be able to correctly monitor the wear status of bearings 32 and 33.

[0067] Here, even if a microcontroller drive voltage V2, which is less than the microcontroller operating voltage V3, is supplied to the microcontroller 82, the CPU 82a can still execute the BIOS program P2. Specifically, first, the microcontroller 82 starts up when the microcontroller drive voltage V2 is supplied to it. Next, the CPU 82a starts executing the BIOS program P2 stored in the ROM 82c. Then, the initialization of the hardware resources of the monitoring device 5 is performed. Next, the CPU 82a finishes executing the BIOS program P2. Next, the CPU 82a executes the control program P1. That is, the control program P1 starts up. At this time, the microcontroller 82 may malfunction. In other words, the timing of the start of the malfunction of the microcontroller 82 is when the execution of the BIOS program P2 finishes and the control program P1 starts up.

[0068] ●Operation of the control circuit (this method)● Next, the operation of this circuit 8 (this method) will be explained below. Figures 1 to 6 will be referred to as appropriate in the following explanation.

[0069] Figure 7 is a flowchart showing an example of the operation of this circuit 8.

[0070] As described above, this circuit 8 resets the microcontroller 82 based on the microcontroller drive voltage V2 supplied from the voltage generation unit 81. This circuit 8 repeatedly resets the microcontroller 82 until the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3.

[0071] In the following description, inverter I supplies a control voltage V1 to the pump 1 (motor unit 3) and the monitoring device 5 (circuit 8). At this time, the control voltage V1 changes (increases) over time from 0V to 200V. The rotor 34 rotates at a predetermined rotational speed based on the frequency corresponding to the control voltage V1 supplied from inverter I.

[0072] First, the voltage generation unit 81 generates a microcontroller drive voltage V2 based on the control voltage V1 supplied from the inverter I (ST1: voltage generation step).

[0073] Next, the voltage generation unit 81 supplies the microcontroller drive voltage V2 to the microcontroller 82 and the monitoring unit 83 (ST2: voltage supply step). At this time, the microcontroller drive voltage V2 generated in the process (ST1) changes (increases) over time.

[0074] Next, when the microcontroller drive voltage V2 is greater than or equal to the abnormal signal generation voltage V5 and less than the monitoring unit operating voltage V4 ("Y" in ST3), this circuit 8 executes the first reset process (ST4). Details of the first reset process (ST4) will be described later.

[0075] Next, when the microcontroller drive voltage V2 is equal to or greater than the monitoring unit operating voltage V4 ("N" in ST3), the monitoring unit 83 compares the microcontroller drive voltage V2 with the microcontroller operating voltage V3 (ST5: comparison step). The process (ST5) is an example of a reset step in the present invention.

[0076] When the microcontroller drive voltage V2 is less than the microcontroller operating voltage V3 (ST5 "Y"), this circuit 8 executes the second reset process (ST6). Details of the second reset process (ST6) will be described later.

[0077] On the other hand, when the microcontroller drive voltage V2 is equal to or greater than the microcontroller operating voltage V3 ("N" in ST5), the operation of this circuit 8 (this method) terminates.

[0078] ●First reset process Figure 8 is a flowchart showing an example of the first reset process (ST4).

[0079] The "first reset process (ST4)" is a process that resets the microcontroller 82 when the microcontroller drive voltage V2 is equal to or greater than the abnormal signal generation voltage V5 and less than the monitoring unit operating voltage V4. The first reset process (ST4) is an example of a reset step in the present invention.

[0080] When the microcontroller drive voltage V2 changes (rises) from 0V to the abnormal signal generation voltage V5, this circuit 8 executes the first reset process (ST4). At this time, the microcontroller 82 is running, and the CPU 82a has started executing the BIOS program P2.

[0081] First, the monitoring unit 83 generates an abnormal signal S1 (ST41: first signal generation step).

[0082] Next, the monitoring unit 83 sends the generated abnormal signal S1 to the microcontroller 82 as a reset signal S2 (ST42: first signal transmission step). At this time, the abnormal signal S1 is sent to the microcontroller 82 before the CPU 82a executes the control program P1 (the control program P1 is started).

[0083] Next, the microcontroller 82 receives the abnormal signal S1 and resets itself (ST43: First reset step).

[0084] Next, the circuit 8 completes the first reset process (ST4), and the operation of the circuit 8 returns to process (ST3). As a result, the first reset process (ST4) is repeatedly executed, and the microcontroller 82 is repeatedly reset, until the microcontroller drive voltage V2 becomes equal to or greater than the monitoring unit operating voltage V4 ("N" in ST3).

[0085] Here, the microcontroller 82, having reset itself, restarts due to the continuously supplied microcontroller drive voltage V2, and the CPU 82a begins re-executing the BIOS program P2. However, as mentioned above, the monitoring unit 83 continuously sends an abnormal signal S1 to the microcontroller 82 until the microcontroller drive voltage V2 becomes the monitoring unit operating voltage V4. Each time the microcontroller 82 restarts (the CPU 82a starts re-executing the BIOS program P2), it receives the abnormal signal S1 and repeatedly resets itself. Therefore, the control program P1 does not start until the microcontroller drive voltage V2 becomes the monitoring unit operating voltage V4. In other words, the microcontroller 82 cannot malfunction. Thus, malfunction of the microcontroller 82 is prevented.

[0086] ●Second reset process Figure 9 is a flowchart showing the second reset process (ST6).

[0087] The "second reset process (ST6)" is a process that resets the microcontroller 82 when the microcontroller drive voltage V2 is equal to or greater than the monitoring unit operating voltage V4 and less than the microcontroller operating voltage V3. The second reset process (ST6) is an example of a reset step in the present invention.

[0088] When the microcontroller drive voltage V2 changes (rises) from the abnormal signal generation voltage V5 to the monitoring unit operating voltage V4, this circuit 8 executes the second reset process (ST6). At this time, the microcontroller 82 has started up (restarted), and the CPU 82a has started executing (re-executing) the BIOS program P2.

[0089] First, the monitoring unit 83 generates a reset signal S2 (ST61: second signal generation step). The second signal generation step is an example of a signal transmission step in the present invention.

[0090] Next, the monitoring unit 83 transmits the generated reset signal S2 to the microcontroller 82 (ST62: second signal transmission step). At this time, the reset signal S2 is transmitted to the microcontroller 82 before the CPU 82a executes the control program P1 (the control program P1 is started). The second signal transmission step is an example of a signal transmission step in the present invention.

[0091] Next, the microcontroller 82 receives the reset signal S2 and resets itself (ST63: second reset step).

[0092] Next, the circuit 8 completes the second reset process (ST6), and the operation of the circuit 8 returns to process (ST5). As a result, the second reset process (ST6) is repeatedly executed, and the microcontroller 82 is repeatedly reset, until the microcontroller drive voltage V2 becomes equal to or greater than the microcontroller operating voltage V3 ("N" in ST5).

[0093] Here, the microcontroller 82, having reset itself, restarts due to the continuously supplied microcontroller drive voltage V2, and the CPU 82a begins re-executing the BIOS program P2. However, as mentioned above, the monitoring unit 83 intermittently sends a reset signal S2 to the microcontroller 82 until the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3. The period during which the monitoring unit 83 sends the reset signal S2 is from after the startup of the microcontroller 82 until before the start of abnormal operation of the microcontroller 82 (when the control program P1 starts after the execution of the BIOS program P2 has finished). The microcontroller 82 receives the reset signal S2 before the start of abnormal operation of the microcontroller 82 and repeatedly resets itself. Therefore, the control program P1 does not start until the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3. In other words, the microcontroller 82 cannot operate abnormally. Therefore, abnormal operation of the microcontroller 82 is prevented.

[0094] In this way, the circuit 8 prevents abnormal operation of the microcontroller 82 by executing the first reset process (ST4) and the second reset process (ST6) until the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3. When the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3, the CPU 82a can correctly execute the control program P1. That is, the monitoring device 5 functions normally as a bearing wear monitoring device.

[0095] ●Summary As described above, this circuit 8 is a control circuit used in this pump 1, which is driven by a control voltage V1 supplied from the inverter I. This circuit 8 comprises a voltage generation unit 81, a microcontroller 82, and a monitoring unit 83. The voltage generation unit 81 generates the microcontroller drive voltage V2 of the microcontroller 82 based on the control voltage V1. The monitoring unit 83 monitors the microcontroller drive voltage V2. The monitoring unit 83 resets the microcontroller 82 when the microcontroller drive voltage V2 is less than the microcontroller operating voltage V3 of the microcontroller 82. With this configuration, the microcontroller 82 resets itself until the microcontroller drive voltage V2 supplied to the microcontroller 82 becomes the microcontroller operating voltage V3. Therefore, even if a microcontroller drive voltage V2 less than the microcontroller operating voltage V3 is supplied to the microcontroller 82, the microcontroller 82 cannot malfunction. In other words, malfunction of the microcontroller 82 is prevented.

[0096] According to the above explanation, the microcontroller drive voltage V2 is supplied to the monitoring unit 83. The monitoring unit 83's operating voltage V4 (e.g., 3.3V) is less than or equal to the microcontroller operating voltage V3 (e.g., 5V). When the microcontroller drive voltage V2 supplied to the monitoring unit 83 is less than the monitoring unit operating voltage V4, the monitoring unit 83 sends an abnormal signal S1 to the microcontroller 82 indicating that the microcontroller drive voltage V2 is less than the monitoring unit operating voltage V4, causing the microcontroller 82 to reset. With this configuration, the microcontroller 82 receives the abnormal signal S1 and resets itself until the microcontroller drive voltage V2 supplied to the microcontroller 82 becomes the monitoring unit operating voltage V4. Therefore, even if a microcontroller drive voltage V2 less than the monitoring unit operating voltage V4 is supplied to the microcontroller 82, the microcontroller 82 cannot malfunction. In other words, malfunction of the microcontroller 82 is prevented.

[0097] According to the above explanation, the microcontroller drive voltage V2 is supplied to the monitoring unit 83. The monitoring unit 83's operating voltage V4 (e.g., 3.3V) is less than the microcontroller operating voltage V3 (e.g., 5V). When the microcontroller drive voltage V2 supplied to the monitoring unit 83 is equal to or greater than the monitoring unit operating voltage V4 and less than the microcontroller operating voltage V3, the monitoring unit 83 sends a reset signal S2 to the microcontroller 82 to reset it. With this configuration, the microcontroller 82 receives the reset signal S2 and resets itself until the microcontroller drive voltage V2 supplied to the microcontroller 82 becomes the microcontroller operating voltage V3. Therefore, even if a microcontroller drive voltage V2 less than the microcontroller operating voltage V3 is supplied to the microcontroller 82, the microcontroller 82 cannot malfunction. In other words, malfunction of the microcontroller 82 is further prevented.

[0098] As explained above, the monitoring unit 83 continuously sends a reset signal S2 to the microcontroller 82 until the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3. With this configuration, each time the microcontroller 82 restarts, it receives the reset signal S2 and repeatedly resets itself. Therefore, the microcontroller 82 cannot malfunction until the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3. In other words, malfunction of the microcontroller 82 is reliably prevented.

[0099] As explained above, the monitoring unit 83 intermittently sends a reset signal S2 to the microcontroller 82 until the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3. With this configuration, the monitoring unit 83 sends a reset signal S2 to the microcontroller 82 at a predetermined timing (for example, after the microcontroller 82 starts up). Each time the microcontroller 82 restarts, it receives the reset signal S2 and repeatedly resets itself. Therefore, the microcontroller 82 cannot malfunction until the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3. In other words, malfunction of the microcontroller 82 is prevented. In addition, the power consumption of the microcontroller 82 is suppressed compared to the case where the monitoring unit 83 continuously sends the reset signal S2 to the microcontroller 82.

[0100] As explained above, the reset signal S2 is transmitted after the startup of the microcontroller 82 and before the start of any abnormal operation of the microcontroller 82. With this configuration, the period during which the monitoring unit 83 transmits the reset signal S2 is from after the startup of the microcontroller 82 until before the start of any abnormal operation of the microcontroller 82 (for example, after the end of execution of the BIOS program P2 and before the start of the control program P1). Therefore, the microcontroller 82 receives the reset signal S2 before the start of any abnormal operation of the microcontroller 82 and repeatedly resets itself. As a result, the microcontroller 82 cannot malfunction until the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3. In other words, by transmitting the reset signal S2 within a predetermined period, any abnormal operation of the microcontroller 82 is further prevented.

[0101] As described above, this method is a control method performed by the circuit 8 used in the pump 1, which is driven by a control voltage V1 supplied from an inverter I. The circuit 8 comprises a voltage generation unit 81, a microcontroller 82, and a monitoring unit 83. The voltage generation unit 81 generates a microcontroller drive voltage V2 based on the control voltage V1. The monitoring unit 83 monitors the microcontroller drive voltage V2. This method includes a reset step (processing ST4, ST6) in which the circuit 8 resets the microcontroller 82 when the microcontroller drive voltage V2 is less than the microcontroller operating voltage V3. With this configuration, the microcontroller 82 resets itself until the microcontroller drive voltage V2 supplied to the microcontroller 82 becomes the microcontroller operating voltage V3. Therefore, even if a microcontroller drive voltage V2 less than the microcontroller operating voltage V3 is supplied to the microcontroller 82, the microcontroller 82 cannot malfunction. In other words, malfunction of the microcontroller 82 is prevented.

[0102] According to the above explanation, the reset step (processing ST4, ST6) includes a comparison step (processing ST5) and a signal transmission step (processing ST61, ST62). In the comparison step (processing ST5), the circuit 8 compares the microcontroller drive voltage V2 and the microcontroller operating voltage V3. In the signal transmission steps (processing ST61, ST62), when the microcontroller drive voltage V2 is less than the microcontroller operating voltage V3, the circuit 8 generates a reset signal S2 to reset the microcontroller 82 and transmits the generated reset signal S2 to the microcontroller 82. With this configuration, the circuit 8 transmits the reset signal S2 to the microcontroller 82 based on the result of comparing the microcontroller drive voltage V2 and the microcontroller operating voltage V3. The microcontroller 82 receives the reset signal S2 and resets itself until the microcontroller drive voltage V2 supplied to the microcontroller 82 becomes the microcontroller operating voltage V3. Therefore, even if a microcontroller drive voltage V2, which is less than the microcontroller operating voltage V3, is supplied to the microcontroller 82, the microcontroller 82 cannot malfunction. In other words, malfunctions of the microcontroller 82 are further prevented.

[0103] According to the above description, the pump 1 is a pump driven by a control voltage V1 supplied from an inverter I. The pump 1 comprises a motor unit 3 and this circuit 8. The control voltage V1 is supplied to the motor unit 3 and this circuit 8. The motor unit 3 comprises a rotating shaft 31, bearings 32, 33, a rotor 34, and a stator 35. The rotating shaft 31 rotates together with the rotor 34. The bearings 32, 33 support the rotating shaft 31. The stator 35 rotates the rotor 34. This circuit 8 is a control circuit for a monitoring device 5 (bearing wear monitoring device) that monitors the wear condition of the bearings 32, 33. With this configuration, the microcontroller 82 resets itself until the microcontroller drive voltage V2 supplied to the microcontroller 82 becomes the microcontroller operating voltage V3. Therefore, even if a microcontroller drive voltage V2 less than the microcontroller operating voltage V3 is supplied to the microcontroller 82, the microcontroller 82 cannot malfunction. In other words, abnormal operation of the microcontroller 82 is prevented. When the microcontroller drive voltage V2 becomes the microcontroller operating voltage V3, the monitoring device 5 functions normally as a bearing wear monitoring device and can monitor the wear condition of the bearings 32 and 33 of the pump 1. Therefore, in the pump 1 in which this circuit 8 is introduced to the monitoring device 5, the control voltage V1 supplied from the inverter I can be shared between the pump 1 (motor section 3) and the monitoring device 5 (this circuit 8).

[0104] ●Other Embodiments● In the present invention, the pump 1 is not limited to a canned motor pump.

[0105] In the present invention, the liquid being handled is not limited to high-temperature liquids. That is, for example, the liquid being handled may be a cryogenic liquid or a highly hazardous liquid (e.g., an explosive, flammable, corrosive, or toxic liquid).

[0106] In the present invention, bearings 32 and 33 are not limited to sliding bearings.

[0107] In this invention, the motor drive frequency can be selected according to the operating environment of the pump 1 and is not limited to 50Hz.

[0108] In the present invention, the circuit 8 is not limited to the control circuit of the monitoring device 5 (bearing wear monitoring device) that monitors the wear condition of the bearings 32 and 33. That is, for example, the circuit 8 may be the control circuit of a pump monitoring device that monitors (detects) the state of the pump 1 (e.g., the vibration state of the rotating shaft) or abnormalities in the pump 1 (e.g., abnormalities in the discharge pressure value of the handled fluid or abnormalities in the suction and discharge states of the handled fluid).

[0109] In the present invention, the period during which the monitoring unit 83 transmits the reset signal S2 is not limited to the period from after the startup of the microcontroller 82 until before the start of abnormal operation of the microcontroller 82. That is, for example, the period during which the monitoring unit 83 transmits the reset signal S2 may be until immediately after the execution of the control program P1.

[0110] In this invention, the microcontroller operating voltage V3 is not limited to 5V.

[0111] In the present invention, the monitoring unit operating voltage V4 is not limited to 3.3V, but may be less than or equal to the microcontroller operating voltage V3. In this case, for example, when the monitoring unit operating voltage V4 is the same voltage as the microcontroller operating voltage V3 (for example, 5V), the monitoring unit 83 may send only an abnormal signal S1 to the microcontroller 82 to reset the microcontroller 82 until the microcontroller drive voltage V2 changes (rises) over time from 0V to 5V. In this case, the circuit 8 only needs to perform the first reset process (ST4) and does not need to perform the second reset process (ST6).

[0112] In the present invention, the abnormal signal generation voltage V5 is not limited to 0.5V, but is only required to be less than the monitoring unit operating voltage V4.

[0113] ●Embodiments of the present invention● Next, embodiments of the present invention as understood from the embodiments described above will be described below, with reference to the terms and reference numerals described in each embodiment.

[0114] A first embodiment of the present invention is a control circuit (e.g., this circuit 8) used in a pump (e.g., this pump 1) driven by a drive voltage (e.g., control voltage V1) supplied from an inverter (e.g., inverter I), comprising: a microcontroller (e.g., microcontroller 82); a voltage generation unit (e.g., voltage generation unit 81) that generates a microcontroller drive voltage (e.g., microcontroller drive voltage V2) of the microcontroller based on the drive voltage; and a monitoring unit (e.g., monitoring unit 83) that monitors the microcontroller drive voltage, wherein the monitoring unit is a control circuit that resets the microcontroller when the microcontroller drive voltage is less than the microcontroller operating voltage (e.g., microcontroller operating voltage V3) of the microcontroller. With this configuration, even if the microcontroller is supplied with a drive voltage lower than its operating voltage, the microcontroller cannot malfunction. In other words, malfunctions of the microcontroller are prevented.

[0115] A second embodiment of the present invention is a control circuit in which, in the first embodiment, the microcontroller drive voltage is supplied to the monitoring unit, the monitoring unit operating voltage (e.g., monitoring unit operating voltage V4, 3.3V or 5V) is less than or equal to the microcontroller operating voltage (e.g., 5V), and when the microcontroller drive voltage supplied to the monitoring unit is less than the monitoring unit operating voltage, the monitoring unit transmits an abnormal signal (e.g., abnormal signal S1) to the microcontroller indicating that the microcontroller drive voltage is less than the monitoring unit operating voltage, thereby resetting the microcontroller. With this configuration, even if the microcontroller drive voltage is below the monitoring unit's operating voltage, the abnormal signal generated by the monitoring unit prevents the microcontroller from malfunctioning.

[0116] A third embodiment of the present invention is a control circuit in which, in the first or second embodiment, the microcontroller drive voltage is supplied to the monitoring unit, the monitoring unit operating voltage (e.g., monitoring unit operating voltage V4, 3.3V) is less than the microcontroller operating voltage (e.g., 5V), and when the microcontroller drive voltage supplied to the monitoring unit is greater than or equal to the monitoring unit operating voltage and less than the microcontroller operating voltage, the monitoring unit transmits a reset signal (e.g., reset signal S2) to the microcontroller to reset the microcontroller. With this configuration, the reset signal generated by the monitoring unit further prevents abnormal operation of the microcontroller.

[0117] A fourth embodiment of the present invention is a control circuit in the third embodiment in which the monitoring unit continuously transmits the reset signal to the microcontroller until the microcontroller drive voltage becomes the microcontroller operating voltage. This configuration ensures that malfunctions of the microcontroller are reliably prevented.

[0118] A fifth embodiment of the present invention is a control circuit in the third embodiment in which the monitoring unit intermittently transmits the reset signal to the microcontroller until the microcontroller drive voltage becomes the microcontroller operating voltage. With this configuration, the power consumption of the microcontroller is reduced compared to when the monitoring unit continuously sends reset signals to the microcontroller.

[0119] A sixth embodiment of the present invention is a control circuit in which, in the fifth embodiment, the reset signal is transmitted after the startup of the microcontroller and before the start of any abnormal operation of the microcontroller (for example, "CPU 82a is unable to correctly acquire (read) various information stored in ROM 82c"). With this configuration, abnormal operation of the microcontroller is further prevented by sending a reset signal at predetermined intervals.

[0120] A seventh embodiment of the present invention is a control method (e.g., the method) performed by a control circuit (e.g., the circuit 8) used in a pump (e.g., the pump 1) driven by a drive voltage (e.g., control voltage V1) supplied from an inverter (e.g., inverter I), wherein the control circuit comprises a microcontroller (e.g., microcontroller 82), a voltage generation unit (e.g., voltage generation unit 81) that generates a microcontroller drive voltage (e.g., microcontroller drive voltage V2) of the microcontroller based on the drive voltage, and a monitoring unit (e.g., monitoring unit 83) that monitors the microcontroller drive voltage, and the control method includes a reset step (e.g., processes ST4, ST6) in which the control circuit resets the microcontroller when the microcontroller drive voltage is less than the microcontroller operating voltage (e.g., microcontroller operating voltage V3) of the microcontroller. With this configuration, even if the microcontroller is supplied with a drive voltage lower than its operating voltage, the microcontroller cannot malfunction. In other words, malfunctions of the microcontroller are prevented.

[0121] An eighth embodiment of the present invention is a control method in which, in the seventh embodiment, the reset step includes a comparison step (e.g., process ST5) in which the control circuit compares the microcontroller drive voltage with the microcontroller operating voltage, and a signal transmission step (e.g., processes ST61, ST62) in which the control circuit generates a reset signal (e.g., reset signal S2) to reset the microcontroller when the microcontroller drive voltage is less than the microcontroller operating voltage, and transmits the generated reset signal to the microcontroller. With this configuration, the reset signal generated by the control circuit further prevents abnormal operation of the microcontroller.

[0122] A ninth embodiment of the present invention is a pump (e.g., this pump 1) driven by a drive voltage (e.g., control voltage V1) supplied from an inverter (e.g., inverter I), comprising a motor unit (e.g., motor unit 3) to which the drive voltage is supplied, and a control circuit (e.g., this circuit 8) described in the first embodiment, wherein the motor unit comprises a rotor (e.g., rotor 34), a stator (e.g., stator 35) that rotates the rotor, a rotating shaft (e.g., rotating shaft 31) that rotates together with the rotor, and bearings (e.g., bearings 32, 33) that support the rotating shaft, and the control circuit is a control circuit for a bearing wear monitoring device (e.g., monitoring device 5) that monitors the wear state of the bearings. With this configuration, in a pump where this circuit is introduced into the monitoring device, the control voltage supplied from the inverter can be shared between the pump (motor section) and the monitoring device (this circuit). [Explanation of Symbols]

[0123] 1 pump (pump) 3. Motor section 31 Rotation axis 32 bearings 33 Bearings 34 rotors 35 stata 5. Monitoring device (bearing wear monitoring device) 8-circuit (control circuit) 81 Voltage generation unit 82 Microcontrollers 83 Monitoring Department I Inverter S1 abnormal signal S2 Reset signal V1 Control voltage (drive voltage) V2 Microcontroller drive voltage V3 Microcontroller operating voltage V4 Monitoring Unit Operating Voltage

Claims

1. A control circuit for a bearing wear monitoring device equipped in a pump driven by a drive voltage supplied from an inverter, Microcontroller and A voltage generation unit that generates the microcontroller drive voltage of the microcontroller based on the aforementioned drive voltage, A monitoring unit that monitors the microcontroller drive voltage, It has, The monitoring unit resets the microcontroller when the microcontroller drive voltage is less than the microcontroller operating voltage. Control circuit.

2. The microcontroller drive voltage is supplied to the monitoring unit, The operating voltage of the monitoring unit is less than or equal to the operating voltage of the microcontroller. When the microcontroller drive voltage supplied to the monitoring unit is less than the monitoring unit operating voltage, the monitoring unit transmits an abnormal signal to the microcontroller indicating that the microcontroller drive voltage is less than the monitoring unit operating voltage, causing the microcontroller to reset. The control circuit according to claim 1.

3. The microcontroller drive voltage is supplied to the monitoring unit, The operating voltage of the monitoring unit is less than the operating voltage of the microcontroller. When the microcontroller drive voltage supplied to the monitoring unit is equal to or greater than the monitoring unit operating voltage and less than the microcontroller operating voltage, the monitoring unit sends a reset signal to the microcontroller to reset it. The control circuit according to claim 1 or 2.

4. The monitoring unit continuously transmits the reset signal to the microcontroller until the microcontroller drive voltage becomes the microcontroller operating voltage. The control circuit according to claim 3.

5. The monitoring unit intermittently transmits the reset signal to the microcontroller until the microcontroller drive voltage becomes the microcontroller operating voltage. The control circuit according to claim 3.

6. The reset signal is transmitted after the startup of the microcontroller and before the start of any malfunction of the microcontroller. The control circuit according to claim 5.

7. A control method performed by a control circuit of a bearing wear monitoring device equipped in a pump driven by a drive voltage supplied from an inverter, The aforementioned control circuit is Microcontroller and A voltage generation unit that generates the microcontroller drive voltage of the microcontroller based on the aforementioned drive voltage, A monitoring unit that monitors the microcontroller drive voltage, It has, The control method described above is The control circuit performs a reset step in which it resets the microcontroller when the microcontroller drive voltage is less than the microcontroller operating voltage of the microcontroller. including, Control method.

8. The reset step is, The control circuit includes a comparison step of comparing the microcontroller drive voltage and the microcontroller operating voltage, The control circuit, when the microcontroller drive voltage is less than the microcontroller operating voltage, generates a reset signal to reset the microcontroller and transmits the generated reset signal to the microcontroller in a signal transmission step, including, The control method according to claim 7.

9. A pump that is driven by a drive voltage supplied from an inverter, The motor section to which the aforementioned drive voltage is supplied, A bearing wear monitoring device that monitors the condition of the motor section, It has, The motor section is Rotor and, A stator that rotates the rotor, A rotating shaft that rotates together with the rotor, A bearing that supports the aforementioned rotating shaft, Equipped with, The bearing wear monitoring device is The wear condition of the bearing is monitored, Control circuit according to claim 1, Equipped with, pump.

Images