Circuit board and management system

Abstract

This circuit board includes: a power supply circuit; a signal line and a ground line each connected to the power supply circuit; a capacitor connected between the signal line and the ground line; and an RFID module. The RFID module includes: a first terminal and a second terminal which are respectively connected to both ends of the capacitor; an RFIC which is connected to each of the first terminal and the second terminal, and detects a capacitance value or resistance value of the capacitor; and antennas which receive radio waves of wireless communication from a reader, and transmit the detected capacitance value or resistance value to the reader.

Description

Circuit board and management system

[0001] The present invention relates to a circuit board for detecting the state of a capacitor and a management system including the same.

[0002] Conventionally, circuit boards have included capacitors to stabilize the power supply. If a capacitor on a circuit board becomes defective, the power supply to the circuit board becomes unstable, and the circuit board may stop functioning. Therefore, the capacitance or resistance of the capacitor is sometimes measured during maintenance of the circuit board.

[0003] There is a semiconductor device that detects the capacitance of a capacitor used as a temperature sensor. For example, Patent Document 1 describes a temperature sensor that detects a change in the environmental temperature by detecting a change in the capacitance of a sensor capacitor.

[0004] JP 2022-120581 A

[0005] However, in order to detect the state of the capacitors on the circuit board, the worker must directly access the capacitors on the circuit board to measure them, which is cumbersome.

[0006] An object of the present invention is to provide a circuit board and a management system that can easily detect the state of a capacitor.

[0007] A circuit board according to one aspect of the present invention includes a power supply circuit, a signal line and a ground line connected to the power supply circuit, a capacitor connected between the signal line and the ground line, and an RFID (Radio Frequency Identification) module. The RFID module includes a first terminal and a second terminal connected to both ends of the capacitor, an RFIC (Radio Frequency Integrated Circuit) connected to the first terminal and the second terminal, respectively, for detecting a capacitance or resistance value of the capacitor, and an antenna for receiving radio waves for wireless communication from a reader and transmitting the detected capacitance or resistance value to the reader.

[0008] A management system according to one aspect of the present invention includes the above-described circuit board, a reader that transmits and receives data to and from an antenna, and a management unit that determines whether a capacitor is abnormal based on the capacitance or resistance value of the capacitor read by the reader.

[0009] According to the present invention, it is possible to provide a circuit board and a management system that can easily detect the state of a capacitor.

[0010] FIG. 1 is a diagram showing a schematic configuration of a management system according to the first embodiment; FIG. 2 is a longitudinal sectional view of an RFID module; FIG. 3 is a functional block diagram showing the internal configuration of an RFIC; FIG. 4 is a circuit diagram showing an example of a power supply circuit and a load; FIG. 5 is a diagram showing a street lamp provided with a conventional circuit board; FIG. 6 is a diagram showing a street lamp provided with a circuit board according to the first embodiment;

[0011] Each of the embodiments described below shows a specific example of the present invention, and the present invention is not limited to this configuration. Furthermore, the numerical values, shapes, configurations, steps, and step orders specifically shown in the following embodiments are examples and do not limit the present invention. Among the components in the following embodiments, components that are not described in the independent claims that represent the highest concepts are described as optional components. Furthermore, in all embodiments, the configurations in each modification are the same, and the configurations described in each modification may be combined with each other.

[0012] (Embodiment 1) Next, a schematic configuration of a management system 1 according to embodiment 1 of the present invention will be described with reference to Figures 1 and 2. Figure 1 is a schematic diagram showing a circuit board 3 on which an RFID module 13 is mounted in the management system 1 of embodiment 1. Figure 2 is a vertical cross-sectional view of the RFID module.

[0013] In the first embodiment, the management system 1 monitors the capacitance value of a capacitor 11 mounted on a circuit board 3. The management system 1 includes the circuit board 3 and a reader 5.

[0014] The circuit board 3 supplies power to perform various tasks and includes a power supply circuit 7, a load 9, a capacitor 11, an RFID module 13, a signal line 15, and a ground line 17. The circuit board 3 has a main body 4 made of, for example, a resin substrate.

[0015] The power supply circuit 7 is a circuit that supplies power to the load 9. The power supply circuit 7 has a set voltage to supply depending on the type of load 9. The power supply circuit 7 does not need to include a power source or a battery, and converts a DC or AC input voltage into a desired DC voltage and outputs it. FIG. 4 shows an example of the power supply circuit 7 and the load 9. The power supply circuit 7 has, for example, a DC-DC converter IC 7b, and converts a DC voltage input to an input terminal 7a into a DC voltage appropriate for the load 9 and supplies it to the load 9.

[0016] The load 9 consumes power supplied from the power supply circuit 7 to perform work. The load 9 is, for example, a lighting unit or a motor. In the example shown in Fig. 4, the load 9 is a lighting unit having a plurality of LEDs 9a. A signal line 15 and a ground line 17 are connected in parallel between the power supply circuit 7 and the load 9. The ground line 17 is grounded and maintained at a predetermined ground potential.

[0017] Referring to FIG. 1 , one terminal of the capacitor 11 is connected to the signal line 15, and the other terminal is connected to the ground line 17. If the capacitor 11 has polarity, for example, the positive terminal is connected to the signal line 15 and the negative terminal is connected to the ground line 17. The capacitor 11 may be, for example, an electrolytic capacitor having polarity, such as an aluminum capacitor or a tantalum capacitor, or may be a non-polar multilayer ceramic capacitor (MLCC). The capacitor 11 may also be an electric double layer capacitor. The capacitor 11 functions as a decoupling capacitor disposed between the signal line 15 and the ground line 17 on the circuit board 3.

[0018] The RFID module 13 measures the capacitance value of the capacitor 11 using radio waves received from the reader 5 as a power source, and transmits the measured capacitance value to the reader 5. The RFID module 13 includes a sensor for measuring physical parameters within an RFID (Radio Frequency Identification) tag. The RFID module 13 includes a first terminal 21, a second terminal 23, an RFIC 25, and an antenna 27.

[0019] One of the first terminals 21 is connected to the RFIC 25, and the other is connected to one terminal of the capacitor 11. One of the second terminals 23 is connected to the RFIC 25, and the other is connected to the other terminal of the capacitor 11. The first terminal 21 and the second terminal 23 also serve as terminals for connecting an external sensor to the RFIC 25.

[0020] Next, the RFIC 25 will be described with reference to Fig. 3. Fig. 3 is a functional block diagram showing the internal configuration of the RFIC 25.

[0021] The RFIC 25 includes a rectifier circuit 31 , a power supply circuit 32 , a transmitter / receiver circuit 33 , a controller 34 , a capacitance sensor circuit 35 , and a memory 36 .

[0022] The rectifier circuit 31 is connected to the antenna 27, which receives radio waves from the reader 5 and supplies the rectifier circuit 31 with a high-frequency signal representing received information and a high-frequency current for wireless power supply. The rectifier circuit 31 rectifies the high-frequency current to obtain a DC voltage and supplies the power supply circuit 32 with a signal obtained by rectifying and detecting the high-frequency signal and supplies the signal as a received signal to the transmitter / receiver circuit 33. The rectifier circuit 31 also supplies the modulated signal supplied from the transmitter / receiver circuit 33 to the antenna 27.

[0023] The power supply circuit 32 generates a power supply voltage with a constant voltage value based on the DC voltage supplied from the rectifier circuit 31 , and supplies the power supply voltage to the transmitter / receiver circuit 33 , the controller 34 , the memory 36 and the capacitance sensor circuit 35 .

[0024] The transmission / reception circuit 33 demodulates the received signal supplied from the rectifier circuit 31 to obtain a command code, and supplies the command code to the controller 34. The transmission / reception circuit 33 also supplies the rectifier circuit 31 with a modulated signal obtained by modulating a carrier signal corresponding to, for example, the UHF band, HF (High Frequency) band, or LF (Low Frequency) band used in short-range wireless communication with transmission information supplied from the controller 34.

[0025] The controller 34 reads and captures the identification ID stored in the memory 36. The controller 34 also supplies various control signals to the capacitance sensor circuit 35 to detect the capacitance of the capacitor 11 externally connected to the RFIC 25.

[0026] The capacitance sensor circuit 35 detects the capacitance value by comparing the capacitance of the capacitor 11 with a reference capacitance in response to various control signals. The capacitance sensor circuit 35 transmits the detection result of the capacitance value to the controller 34.

[0027] The controller 34 transmits information including the capacitance detection result and its own identification ID to the transmitting / receiving circuit 33 as transmission information.

[0028] The controller 34 also controls the write voltage and erase voltage for the memory 36 in order to write the capacitance value of the capacitor 11 detected by the capacitance sensor circuit 35 into the memory 36 .

[0029] The transmitter / receiver circuit 33 wirelessly transmits the transmission information including the capacitance value information and the identification ID to the reader 5. As a result, information indicating the capacitance value of the capacitor 11 detected by the RFID module 13 is transmitted to the reader 5.

[0030] The memory 36 is a non-volatile semiconductor memory, and is configured by a capacitor made of an NMOS transistor (NMOS capacitor) in the embodiment 1. The memory 36 stores the identification ID of the RFID module 13 and the value of a trimming signal indicating the calibration result of the capacitance sensor circuit 35.

[0031] Such a passively operating RFID module 13 is disclosed in, for example, Japanese Patent Application Laid-Open No. 2022-120581, and therefore a detailed description thereof will be omitted here.

[0032] The reader 5 reads the detection results of the RFID module 13 and transmits the capacitance value information and the identification ID of the RFID module 13 to the management unit 29. The reader 5 may be, for example, portable, and an operator may bring the reader 5 close to the inspection object to communicate with the RFID module 13. Furthermore, when a fixed reader 5 is used, the reader 5 periodically communicates with the RFID module 13 and acquires the detection results of the RFID module 13. The reader 5 may be a reader / writer having a writing function that writes information to the RFID module 13.

[0033] In this way, the RFIC 25 detects the capacitance value of the capacitor 11 by utilizing the energy of the communication signal transmitted from the reader 5, and transmits the detection result together with the identification ID back to the reader 5. The reader 5 transmits the received detection result of the RFID module 13 and the identification ID as a set to the management unit 29.

[0034] The management unit 29 determines whether there is an abnormality in the capacitor 11 associated with the identification ID based on the received capacitance value information. The management unit 29 may be configured as an information processing device such as a personal computer or a workstation, or as a tablet terminal. The management unit 29 includes, for example, a processor (MPU), an input device such as a keyboard, a mouse, or a touch panel, and a display. The management unit 29 has a memory unit, and the memory unit includes, for example, at least one of a hard disk drive (HDD), a semiconductor storage device (SSD), and a semiconductor memory (RAM).

[0035] The management unit 29 compares the detected capacitance value with a predetermined threshold value indicating that the time for replacement has come, and if the detected capacitance value is equal to or less than the threshold value, it determines that an abnormality has occurred in the capacitor 11 and that the time for replacement has come, and displays information on the display urging the user to replace the capacitor 11. This allows the worker to prevent the circuit board 3 from becoming inoperable by replacing the capacitor 11 with a new one. If the detected capacitance value is greater than the threshold value, the management unit 29 displays on the display that the capacitor 11 is normal.

[0036] Furthermore, if the capacitor 11 is an electrolytic capacitor, its capacitance value will naturally decrease due to factors such as the evaporation of the components inside. Because the amount of capacitance decrease varies depending on the temperature environment, it is also possible to predict the lifespan of the capacitor 11 from changes in the amount of capacitance decrease due to usage conditions. The management unit 29 monitors the detected capacitance value and predicts the capacitor's lifespan based on changes in the capacitance value over a predetermined period. For example, the management unit 29 uses a graph showing changes in the capacitance value over a predetermined period to predict when in the future the capacitance value will fall below a predetermined threshold. The management unit 29 displays the predicted lifespan on a display. If the displayed end of life date is before the next maintenance period, the operator can replace the capacitor 11 with a new one to prevent the circuit board 3 from malfunctioning.

[0037] Use of the circuit board 3 of the first embodiment significantly improves maintenance work for the circuit board. Please refer to Figures 5 and 6. Figure 5 is an explanatory diagram showing a street light 41 equipped with a conventional circuit board, which is turned on at night. Figure 6 is an explanatory diagram showing a street light 42 equipped with the circuit board 3 of the first embodiment, which is turned off during the day.

[0038] If the circuit board 3 is used in, for example, a street light, conventionally, as shown in Figure 5, power is only supplied to the capacitor at night when the street light 41 is on, making it impossible to measure the capacitance value of the capacitor. Furthermore, measuring the capacitance value of the capacitor on the circuit board of the street light 41 requires working at a height, which is expensive. If the capacitance value of the capacitor is not measured, the street light 41 will suddenly stop lighting up, causing anxiety to cars and people traveling under the street light 41.

[0039] In contrast, by using the circuit board 3 of embodiment 1, the capacitance value of the capacitor 11 can be detected using a wireless signal from the reader 5 as a power source. This allows maintenance work to be performed even during the day when the street light 41 is off, as shown in FIG. 6 . Furthermore, since workers can measure the capacitance value of the circuit board 3 from the ground using the reader 5, there is no need to work at height, significantly reducing maintenance costs. Furthermore, since the management unit 29 can predict the lifespan of the capacitor 11, during periodic maintenance that requires work at height, only capacitors 11 predicted to have a short lifespan can be replaced in advance before they fail. This reduces the need for replacement work when a street light no longer lights up, thereby reducing the need to replace capacitors 11 just for broken street lights and reducing maintenance costs.

[0040] Furthermore, when a circuit board is used as a circuit board for a vehicle's headlights or taillights, maintenance work for these has traditionally been performed manually by an operator. By using the circuit board 3 of embodiment 1, an operator can wirelessly check the capacitance value of the capacitor 11 from outside the vehicle using the reader 5, which allows for easy checking even when the capacitor is installed in a location that is normally out of sight, thereby improving workability. Furthermore, if the reader 5 is provided inside the vehicle, the vehicle itself can check the capacitance value of the capacitor 11 during autonomous driving, enabling self-maintenance.

[0041] As described above, the circuit board 3 of the first embodiment includes the power supply circuit 7, the signal line 15 and the ground line 17 connected to the power supply circuit 7, the capacitor 11 connected between the signal line 15 and the ground line 17, and the RFID module 13. The RFID module 13 includes the first terminal 21 and the second terminal 23 connected to both ends of the capacitor 11, the RFIC 25 connected to the first terminal 21 and the second terminal 23, respectively, and detecting the capacitance or resistance value of the capacitor 11, and the antenna 27 receiving radio waves for wireless communication from the reader 5 and transmitting the detected capacitance or resistance value to the reader.

[0042] With this configuration of circuit board 3, even when power is not being supplied to circuit board 3, the capacitance value or resistance value of capacitor 11 can be detected using the radio waves of wireless communication from reader 5 as a power source, making it possible to easily detect the state of capacitor 11.

[0043] Next, a first modification of the circuit board of the first embodiment will be described with reference to FIG. 7 . FIG. 7 is an explanatory diagram illustrating the configuration of a circuit board 3A of the first modification of the first embodiment. In the RFID module 13 of the circuit board 3 described above, the antenna 27 is housed in a chip-type tag, but this is not limited to this. The antenna 27 of the RFID module 13 may be disposed on the substrate main body 4 of the circuit board 3. For example, as shown in FIG. 7 , a meander-shaped antenna 27A may be disposed on the substrate main body 4, and the antenna 27A may be connected to the RFIC 25. In this case, a matching circuit may be disposed between the antenna 27A and the RFIC 25 to further improve communication performance. By providing a matching circuit, the wiring disposed on the substrate main body 4 may also be used as a boost antenna.

[0044] Next, a second modification of the circuit board of the first embodiment will be described with reference to FIG. 8 . FIG. 8 is an explanatory diagram illustrating the configuration of a circuit board 3B of the second modification of the first embodiment. In the RFID module 13 of the circuit board 3 described above, the antenna 27 is housed in a chip-type tag, but this is not limited to this. The antenna 27 of the RFID module 13 may be an electrode 27B arranged on the substrate main body 4 of the circuit board 3. For example, as shown in FIG. 8 , a pair of electrodes 27B arranged on the substrate main body 4 may be used as an antenna, and the pair of electrodes 27B may be electrically connected to the RFIC 25. A slit 28 is arranged between the pair of electrodes 27B, so that the potentials of the respective electrodes 27B are different.

[0045] Next, a third modification of the management system 1 of the first embodiment will be described with reference to FIG. 9 . FIG. 9 is a functional block diagram showing the internal configuration of an RFIC in the third modification of the management system 1 of the first embodiment. In the RFID module 13 of the circuit board 3 described above, the management unit 29 determines whether the capacitor 11 is defective by measuring the capacitance value of the capacitor 11, but this is not limiting. The RFID module of the circuit board 3 may also determine whether the capacitor 11 is defective by measuring the impedance of the capacitor 11.

[0046] The RFID module 13C in the third modification has a third terminal 43 and a fourth terminal 44 electrically connected to the controller 34 of the RFIC 25C. An impedance sensor circuit 47 is connected to the third terminal 43 and the fourth terminal 44. The impedance sensor circuit 47 is also connected to the capacitor 11, detects the impedance value (resistance value) of the capacitor 11, and transmits the detected impedance value to the controller 34. The RFID module 13C in the third modification measures the impedance of the capacitor 11, and is therefore suitable for detecting defects in non-polar multilayer ceramic capacitors.

[0047] (Embodiment 2) Next, an RFID module 13D of embodiment 2 will be described with reference to Fig. 10, Fig. 11, and Fig. 12. Fig. 10 is a vertical cross-sectional view showing an example of the configuration of a capacitor-integrated RFID module according to embodiment 2. Fig. 11 is an explanatory diagram showing an example of antenna arrangement in the capacitor-integrated RFID module according to embodiment 2. Fig. 12 is a perspective view showing the connection between the RFIC and side electrodes of the capacitor-integrated RFID module according to embodiment 2.

[0048] In the circuit board 3 of the first embodiment, the RFID module 13 and the capacitor 11 are separately arranged, but in the second embodiment, the RFID module and the capacitor are integrated together. Except for this point and the points described below, the circuit board of the second embodiment has the same configuration as the circuit board 3 of the first embodiment, and therefore a description of the common configuration will be omitted.

[0049] The RFID module 13D of the second embodiment includes a capacitor 11D, a pair of side electrodes 53 connected to both poles of the capacitor 11D, a substrate 55 arranged on the upper surface of the capacitor 11D, an RFIC 25 arranged on the upper surface 55a of the substrate 55, and a resin mold 57 covering the substrate 55 and the RFIC 25.

[0050] A pair of dipole antennas 27D electrically connected to the RFIC 25 are disposed on the upper surface 55a of the substrate 55. The dipole antennas 27D have, for example, a spiral shape.

[0051] 12 , the upper end of each side electrode 53 is in contact with the lower surface 55b of the substrate 55, and wiring 59 connected to each side electrode 53 is disposed on the lower surface 55b. One end of the wiring 59 is connected to the side electrode 53, and the other end passes through the substrate 55 and is connected to the RFIC 25. Therefore, the capacitance sensor circuit 35 of the RFIC 25 is connected to both electrodes of the capacitor 11D via the wiring 59 and the side electrodes 53.

[0052] In this way, by using RFID module 13D that integrates capacitor 11D to be measured and RFIC 25 that measures the capacitance value of capacitor 11D, it is possible to reduce the size of circuit board 3. Furthermore, by incorporating multiple capacitors used on circuit board 3 into RFID module 13D, it is possible to detect the capacitance value of each capacitor with a single measurement, thereby reducing the burden on the worker.

[0053] The dipole antenna 27D disposed on the upper surface 55a of the substrate 55 is not limited to a spiral shape, and may be a meandering shape as shown in Fig. 13. Moreover, instead of the dipole antenna 27D, a loop antenna 27E may be disposed on the upper surface 55a of the substrate 55 as shown in Fig. 14.

[0054] Although the present invention has been described in various embodiments with a certain degree of detail, the disclosure of these embodiments may vary in structural details, and variations in the combination and order of elements in the various embodiments may be realized without departing from the scope and spirit of the invention as claimed.

[0055] A first aspect of the present invention provides a circuit board including a power supply circuit, a signal line and a ground line connected to the power supply circuit, a capacitor connected between the signal line and the ground line, and an RFID module, the RFID module including a first terminal and a second terminal connected to both ends of the capacitor, an RFIC connected to the first terminal and the second terminal, respectively, for detecting a capacitance or resistance value of the capacitor, and an antenna for receiving radio waves for wireless communication from a reader and transmitting the detected capacitance or resistance value to the reader.

[0056] According to the circuit board of the first aspect, even when power is not supplied to the circuit board, the capacitance value or resistance value of the capacitor can be detected using the wireless communication radio waves from the reader as a power source, making it possible to easily detect the state of the capacitor.

[0057] According to a second aspect of the circuit board, in the circuit board of the first aspect, the capacitor is an electrolytic capacitor.

[0058] According to a third aspect of the circuit board, in the circuit board of the first or second aspect, the RFIC includes a capacitance sensor circuit, a control unit, and a memory. The first terminal and the second terminal are connected to the capacitance sensor circuit. The capacitance sensor circuit detects the capacitance value of the capacitor and stores it in the memory. The control unit transmits the stored capacitance value of the capacitor to the outside via the antenna.

[0059] According to a fourth aspect of the circuit board, in the circuit board of the first or second aspect, the RFIC has an impedance sensor circuit, a control unit, and a memory. The first terminal and the second terminal are connected to the impedance sensor circuit. The impedance sensor circuit detects the resistance value of the capacitor and stores it in the memory. The control unit transmits the stored resistance value of the capacitor to the outside from the antenna.

[0060] According to the fifth aspect of the management system, the system comprises a circuit board according to any one of the first to fourth aspects, a reader that transmits and receives signals to and from an antenna, and a management unit that determines whether the capacitor is abnormal based on the capacitance value or resistance value of the capacitor read by the reader.

[0061] According to the management system of the sixth aspect, in the management system of the fifth aspect, the management unit determines whether the capacitor is abnormal by comparing the capacitance value or resistance value of the capacitor read by the reader with a predetermined threshold value.

[0062] According to the seventh aspect of the management system, in the management system of the fifth or sixth aspect, the capacitance or resistance value of the capacitor read by the reader is monitored, and the life of the capacitor is determined based on the change in the capacitance or resistance value over a specified period of time.

[0063] According to the eighth aspect of the RFID module, there is provided a capacitor, a first side electrode and a second side electrode arranged on both sides of the capacitor, an RFIC connected to the first side electrode and the second side electrode, respectively, for detecting the capacitance value or resistance value of the capacitor, and an antenna for receiving radio waves for wireless communication from a reader and transmitting the detected capacitance value or resistance value to the reader.

[0064] 1 Management system 3 Circuit board 4 Board body 5 Reader 7 Power supply circuit 9 Load 11, 11D Capacitor 13, 13D RFID module 15 Signal line 17 Ground line 19 Ground 21 First terminal 23 Second terminal 25, 25C RFIC 27, 27A Antenna 27B Electrode 27D Dipole antenna 28 Slit 29 Management unit 31 Rectifier circuit 32 Power supply circuit 33 Transmitting / receiving circuit 34 Controller 35 Capacitance sensor circuit 36 ​​Memory 41 Street light 43 Third terminal 45 Fourth terminal 47 Impedance sensor circuit 53 Side electrode 55 Board 55a Upper surface 55b Lower surface 57 Resin mold 59 Wiring

Claims

1. A circuit board comprising: a power supply circuit; a signal line and a ground line respectively connected to the power supply circuit; a capacitor connected between the signal line and the ground line; and an RFID module, wherein the RFID module has: a first terminal and a second terminal respectively connected to both ends of the capacitor; an RFIC connected to the first terminal and the second terminal respectively and detecting a capacitance value or a resistance value of the capacitor; and an antenna receiving wireless communication radio waves from a reader and transmitting the detected capacitance value or resistance value to the reader.

2. The circuit board according to claim 1, wherein the capacitor is an electrolytic capacitor.

3. The circuit board according to claim 1 or 2, wherein the RFIC has a capacitance sensor circuit, a control unit, and a memory, the first terminal and the second terminal are connected to the capacitance sensor circuit, the capacitance sensor circuit detects the capacitance value of the capacitor and stores it in the memory, and the control unit transmits the stored capacitance value of the capacitor to the outside from the antenna.

4. The circuit board according to claim 1 or 2, wherein the RFIC has an impedance sensor circuit, a control unit, and a memory, the first terminal and the second terminal are connected to the impedance sensor circuit, the impedance sensor circuit detects the resistance value of the capacitor and stores it in the memory, and the control unit transmits the stored resistance value of the capacitor to the outside from the antenna.

5. A management system comprising: a circuit board according to any one of claims 1 to 4; a reader which transmits and receives signals with the antenna; and a management unit which determines an abnormality in the capacitor based on the capacitance value or the resistance value of the capacitor read by the reader.

6. The management system according to claim 5, wherein the management unit determines whether or not the capacitor is abnormal by comparing the capacitance value or the resistance value of the capacitor read by the reader with a predetermined threshold value.

7. The management system according to claim 5 or 6, wherein the management unit monitors the capacitance value or the resistance value of the capacitor read by the reader and determines the life of the capacitor based on changes in the capacitance value or the resistance value over a specified period of time.

Images