JP7070487B2 - Power supply - Google Patents

Description

The present invention relates to a power supply device that supplies power to a load of an electric device or the like.

Some power supplies are configured as follows. The power supply device includes a first power supply, a second power supply, a plurality of switches including the first switch, a bypass relay, a switch control unit, and a relay control unit. The first switch electrically connects and disconnects the first power supply and a predetermined load. The bypass relay is provided in parallel with the first switch. The switch control unit issues a command to the first switch. The relay control unit controls the bypass relay.

This power supply device is provided with a first path and a second path. The first path electrically connects the first power supply to the switch control unit. The second path electrically connects the second power supply to the switch control unit. Therefore, this power supply device has a redundant configuration in which power can be continuously supplied to the switch control unit from the other path even if an abnormality such as a disconnection occurs in one of the first path and the second path. .. The following Patent Document 1 is a document showing such a technique.

JP-A-2018-68074

In the above power supply device, as described above, even if an abnormality such as a disconnection occurs in one path, power can be continuously supplied to the switch control unit from the other path. However, the inventor has noted that the following problems may still occur in the following cases.

If an abnormality such as a disconnection occurs in one of the first path and the second path, the voltage from the path without the abnormality drops, and the switch control unit commands the first switch. If the voltage is lower than the voltage required to output the switch, the switch control unit cannot issue a command to the first switch. As a result, the first switch may open when it should be closed.

Specifically, when the first switch is a normally open type, the first switch opens when the switch control unit cannot issue a command to the first switch. Further, even if the first switch opens when it receives an open command, closes when it receives a close command, and maintains the current state (open or closed state) when it does not receive any command, the first switch is also used. If the switch control unit cannot issue a command after receiving the open command, the first switch is fixed in the open state. Therefore, there is a risk that the first switch will open when the first switch should be closed.

Further, at these times, the relay control unit also does not close the bypass relay for the following reasons. The relay control unit acquires information about the command from the switch control unit, and closes the bypass relay on condition that the command to all the switches including the first switch is an open command. In that respect, when the above-mentioned first switch opens, the switch control unit cannot issue the command itself, so that the first switch only opens when it should be closed, and the commands to all the switches are opened. It is not a directive. Therefore, in this case, the relay control unit cannot recognize that the command for all the switches is an open command in the command information acquired from the switch control unit, and cannot close the bypass relay.

As a result, both the first switch and the bypass relay may open, making it impossible to supply power to the predetermined load from the first power supply.

The present invention has been made in view of the above circumstances, and in a state where an abnormality such as a disconnection occurs in one of the two paths for supplying power to the switch control unit, a voltage from the path having no abnormality is required. The main purpose is to enable power supply to a predetermined load from the first power source even when the voltage falls below the voltage.

The power supply of the present invention includes a first power supply, a second power supply, a first switch, a bypass relay, a switch control unit, and a relay control unit. The first switch is a switch other than the normally closed type that electrically connects and disconnects the first power supply and a predetermined load. The bypass relay is provided in parallel with the first switch. The switch control unit can issue a command to the first switch on condition that a voltage equal to or higher than a predetermined required voltage is supplied. The relay control unit controls the bypass relay.

The power supply device is provided with a first path, a second path, and a detection unit. The first path electrically connects the first power supply to the switch control unit. The second path electrically connects the second power source to the switch control unit. The detection unit detects an abnormality in at least one of the first path and the second path. The relay control unit closes the bypass relay when the detection unit detects the abnormality.

In the present invention, when the detection unit detects an abnormality in the first path or the second path, the relay control unit closes the bypass relay. In that case, even if the voltage from the path without abnormality falls below the required voltage, the switch control unit cannot issue a command and the first switch opens when it should be closed, the first power supply is bypassed. A predetermined load can be supplied through a relay.

Circuit diagram showing the power supply device of the first embodiment Circuit diagram showing when a predetermined command is issued to each switch Flow chart showing the control of the bypass relay by the relay control unit In the comparative example of this embodiment, the circuit diagram which shows the time when the 2nd path is disconnected Circuit diagram showing when the voltage of the first power supply drops after the disconnection In this embodiment, a circuit diagram showing when the second path is disconnected. Circuit diagram showing when the voltage of the first power supply drops after the disconnection Graph showing the transition of each value at the time of disconnection and subsequent voltage drop Circuit diagram showing the power supply device of the second embodiment Circuit diagram showing when a predetermined command is issued to each switch Circuit diagram showing when a disconnection occurs in the second path Circuit diagram showing when the voltage of the first power supply drops after the disconnection Circuit diagram showing the power supply device of the third embodiment

Next, an embodiment of the present invention will be described. However, the present invention is not limited to the configuration of the embodiment, and can be appropriately modified and implemented without departing from the spirit of the invention.

[First Embodiment]
FIG. 1 is a circuit diagram showing the power supply device 61 of the first embodiment and its surroundings. In addition to the power unit for traveling, the vehicle is equipped with a first load 91, a second load 92, a starter 95, a generator 96, a power supply device 61, and the like.

The power supply device 61 includes a first power supply 11, a second power supply 12, a first switch 21, a second switch 22, a bypass relay 31, a switch control unit 45, and a relay control unit 55. The switch control unit 45 is provided with a first path 41 and a second path 42, and the relay control unit 55 is provided with a first power supply path 51 and a second power supply path 52.

The power unit is an engine in this embodiment. The starter 95 is a device for starting a power unit. The first load 91 and the second load 92 are various electric devices and the like, and include, for example, an ECU and the like. The second load 92 includes a load that causes a failure when the supplied voltage falls below a predetermined second voltage E2 (for example, 7V).

The power supply device 61 supplies power to the starter 95, the first load 91, and the second load 92. Further, in the power supply device 61, the first power supply 11 and the second power supply 12 are charged by the power supply from the generator 96 at a predetermined time.

The first power source 11 is a lead battery in this embodiment. The first power supply 11 is always electrically connected to the generator 96, the starter 95, and the first load 91 regardless of whether the first switch 21, the second switch 22, and the bypass relay 31 are opened or closed. Further, the first power supply 11 is electrically connected to the second load 92 when at least one of the first switch 21 and the bypass relay 31 is closed, and when both the first switch 21 and the bypass relay 31 are opened, the first power supply 11 is electrically connected. It is electrically disconnected from the second load 92.

The second power source 12 is a lithium battery in this embodiment, and is composed of a plurality of battery cells connected in series. The second power supply 12 is electrically connected to the second load 92 when the second switch 22 is closed, and is electrically disconnected from the second load 92 when the second switch 22 is opened. Further, when the first switch 21 or the bypass relay 31 is closed while the second switch 22 is closed, the second power supply 12 is electrically connected to the generator 96, the starter 95, and the first load 91. On the other hand, the second power supply 12 is electrically disconnected from the generator 96, the starter 95, and the first load 91 when the second switch 22 is opened or both the first switch 21 and the bypass relay 31 are opened.

The first and second switches 21 and 22 open when they receive an open command from the switch control unit 45, and close when they receive a close command. Each switch 21 and 22 is a normally open type that opens when neither an open command nor a close command is received.

The switch control unit 45 can transmit a command to each switch 21 and 22 on condition that a voltage equal to or higher than a predetermined first voltage E1 (for example, 9V) is supplied, and controls opening and closing of each switch 21 and 22. do. Therefore, when the voltage supplied to the switch control unit 45 is lower than the first voltage E1, the switch control unit 45 cannot transmit a command to each of the switches 21 and 22. The first voltage E1 is larger than the second voltage E2. The switch control unit 45 transmits the predetermined command information i1 to the relay control unit 55. The command information i1 is information related to commands for the switches 21 and 22.

The first path 41 electrically connects the first power supply 11 to the switch control unit 45. The second path 42 electrically connects the second power supply 12 to the switch control unit 45. Therefore, the power supply device 61 has a redundant configuration in which power can be continuously supplied to the switch control unit 45 even if one of the first path 41 and the second path 42 is disconnected.

The detection unit 54 detects the diagnostic information i2 regarding whether or not the second path 42 is abnormal and transmits it to the relay control unit 55. In the determination of whether or not the abnormality is based on the diagnostic information i2, for example, the voltage value between both ends of the predetermined section of the second path 42 is detected as the diagnostic information i2, and the voltage value is within the range of the voltage value that should be originally. It can be done by determining whether or not. Further, for example, it can be performed by detecting the current value of the current flowing through the second path 42 as the diagnostic information i2 and determining whether or not the current value is within the range of the current value that should be originally.

The bypass relay 31 is provided in parallel with the first switch 21. The bypass relay 31 opens when it receives an open command from the relay control unit 55, and closes when it receives a close command. The bypass relay 31 is a normally closed type that closes when neither an open command nor a close command is received.

The relay control unit 55 can transmit a command to the bypass relay 31 on condition that a voltage equal to or higher than a predetermined third voltage E3 (for example, 5V) is supplied, and controls the opening and closing of the bypass relay 31. Therefore, when the voltage supplied to the relay control unit 55 is lower than the third voltage E3, the relay control unit 55 cannot transmit a command to each bypass relay 31.

The relay control unit 55 closes the bypass relay 31 when all the commands for the switches 21 and 22 are open commands in the command information i1 acquired from the switch control unit 45. Further, the relay control unit 55 closes the bypass relay 31 even when the diagnostic information i2 acquired from the detection unit 54 is information indicating an abnormality. In other cases, the relay control unit 55 opens the bypass relay 31.

The first power supply path 51 electrically connects the first power supply 11 to the relay control unit 55. Further, the second power supply path 52 electrically connects the second power supply 12 to the relay control unit 55. Therefore, the relay control unit 55 also has a redundant configuration in the present embodiment.

In FIG. 2, when the second path 42 is normal, the switch control unit 45 issues a close command to one switch (first switch 21 in the figure) and an open command to the other switch (second switch 22 in the figure). It is a circuit diagram which shows the state which put out. At this time, the command information i1 acquired by the relay control unit 55 from the switch control unit 45 indicates that the command for one of the switches is a close command. Therefore, the relay control unit 55 does not close the bypass relay 31 based on the command information i1. Further, the diagnostic information i2 acquired by the relay control unit 55 from the detection unit 54 indicates that the second path 42 is normal. Therefore, the relay control unit 55 does not close the bypass relay 31 based on the diagnostic information i2. Therefore, the relay control unit 55 opens the bypass relay 31.

FIG. 3 is a flowchart showing control of the bypass relay 31 by the relay control unit 55. The relay control unit 55 determines whether or not the second path 42 is abnormal based on the diagnostic information i2 acquired from the detection unit 54 (S101). When it is determined to be normal (S101: NO), the determination of S101 is repeated at a predetermined cycle. On the other hand, when it is determined to be abnormal (S101: YES), the bypass relay 31 is closed (S102).

FIG. 4 is a circuit diagram showing a power supply device 61R of a comparative example of the present embodiment. The power supply device 61R of this comparative example is different from the present embodiment in that it does not have the detection unit 54. In FIG. 4, as in the case of FIG. 2, in a state where one switch (first switch 21 in the figure) is closed and the other switch (second switch 22 in the figure) and the bypass relay 31 are open, the second path is shown. It shows the case where 42 is broken.

FIG. 5 shows a case where the voltage of the first power supply 11 drops due to, for example, the operation of the starter 95 from the state of FIG. 4, and the voltage from the first path 41 falls below the first voltage E1. Shows. At this time, the switch control unit 45 cannot issue commands to the switches 21 and 22. Therefore, both switches 21 and 22, which are normally open switches, open.

However, along with this, the relay control unit 55 does not become unable to issue a command to the bypass relay 31. This is because the relay control unit 55 is supplied with power from the second power supply 12 by a second power supply path 52 different from the disconnected second path 42. Therefore, even when the switch control unit 45 cannot issue a command and the normally open type switches 21 and 22 are opened in this way, the relay control unit 55 issues a command to the normally closed type bypass relay 31. continue. Therefore, the command is lost and the normally closed bypass relay 31 does not close.

Further, at this time, the relay control unit 55 does not close the bypass relay 31 based on the command information i1 acquired from the switch control unit 45. This is because, here, the switch control unit 45 cannot issue the command itself, and the command for each of the switches 21 and 22 is not an open command. Therefore, the relay control unit 55 cannot recognize that the command for both switches 21 and 22 is an open command in the command information i1. Therefore, as described above, the relay control unit 55 cannot close the bypass relay 31 based on the command information i1.

Therefore, both switches 21 and 22 and the bypass relay 31 are all open. Therefore, it becomes impossible to supply power to the second load 92 from either the first power supply 11 or the second power supply 12.

FIG. 6 shows that in the power supply device 61 of the present embodiment, one switch (first switch 21 in the figure) is closed and the other switch (second switch 22 in the figure) is closed, as in the case of the comparative example (FIG. 4). It is a circuit diagram which shows the case where the 2nd path 42 is disconnected in the state which the bypass relay 31 is open. At this time, the relay control unit 55 closes the bypass relay 31 based on the diagnostic information i2 because the diagnostic information i2 acquired from the detection unit 54 indicates an abnormality in the second path 42.

In FIG. 7, the voltage of the first power supply 11 drops from the state of FIG. 6, as in the case of the comparative example (FIG. 5), so that the voltage from the first path 41 falls below the first voltage E1. Shows the case. At this time, the switch control unit 45 cannot issue commands to the switches 21 and 22 as in the case of the comparative example. Therefore, both switches 21 and 22, which are normally open switches, open. However, unlike the case of the comparative example, since the bypass relay 31 is closed, the power supply path from the first power supply 11 to the second load 92 can be secured by the bypass relay 31.

FIG. 8 is a graph showing the difference in the transition of each value when the second path 42 is disconnected as described above and then the voltage of the first power supply 11 falls below the first voltage E1. Specifically, in each of FIGS. 8A to 8E, the solid line shows the case of this embodiment, and the broken line shows the case of the above comparative example. For figures showing only the solid line and not the dashed line, the dashed line overlaps the solid line.

FIG. 8A is a graph showing the transition of the current flowing through the second path 42. FIG. 8B is a graph showing the transition of commands to the bypass relay 31. FIG. 8C is a graph showing the transition of the voltage between the terminals of the first power supply 11. FIG. 8D is a graph showing the transition of opening and closing of the first switch 21. FIG. 8E is a graph showing the transition of the voltage supplied to the second load 92.

First, a comparative example will be described. As shown in FIG. 8A, even when the second path 42 is disconnected at a predetermined first time point t1 and the current flowing through the second path 42 becomes zero, in the comparative example, FIG. 8 ( As shown by the broken line in b), the command to the bypass relay 31 remains an open command. Therefore, the bypass relay 31 is maintained in an open state.

After that, as shown in FIG. 8C, when the voltage of the first power supply 11 drops for some reason such as the operation of the starter 95 and falls below the first voltage E1 at a predetermined second time point t2, the switch is controlled. The unit 45 cannot issue commands to the switches 21 and 22. Therefore, as shown in FIG. 8D, the switches 21 and 22 (the first switch 21 in the graph), which are normally closed switches, open.

Even at the second time point t2, as shown by the broken line in FIG. 8B, the bypass relay 31 remains open, so that the power is not supplied from the first power supply 11 to the second load 92 via the bypass relay 31. Therefore, as shown in FIG. 8 (d), the power supply to the second load 92 becomes zero at the second time point t2 when the first switch 21 is opened, as shown by the broken line in FIG. 8 (e). Therefore, the voltage supplied to the second load 92 is lower than the second voltage E2. As a result, in the predetermined second load 92, a failure such as initialization or loss of memory occurs.

After that, as shown in FIG. 8C, when the voltage between the terminals of the first power supply 11 recovers and exceeds the first voltage E1 at a predetermined third time point t3, the switch control unit 45 moves each switch 21 and 22. You will be able to issue commands to. As a result, as shown in FIG. 8D, the first switch 21 closes at the third time point t3. As a result, as shown by the broken line in FIG. 8E, the voltage supplied to the second load 92 recovers from zero to the first voltage E1 at the third time point t3. However, with the predetermined second load 92, since the failure has already occurred, there is a possibility that some kind of harmful effect will occur.

Next, this embodiment will be described. As shown in FIG. 8A, when the second path 42 is disconnected at a predetermined first time point t1 and the current flowing through the second path 42 becomes zero, the detection unit 54 detects an abnormality. To. As a result, as shown by the solid line in FIG. 8B, the command to the bypass relay 31 is switched from the open command to the closed command at the first time point t1. Therefore, the bypass relay 31 is closed.

After that, as shown in FIG. 8C, when the voltage of the first power supply 11 drops for some reason and falls below the first voltage E1 at the second time point t2, the switch control unit 45 moves the switches 21 and 22 respectively. I can't give a command to. Therefore, as shown in FIG. 8D, the switches 21 and 22 (the first switch 21 in the graph), which are normally open switches, open.

However, as shown by the solid line in FIG. 8B, at the second time point t2, since the bypass relay 31 is already closed, power is supplied from the first power supply 11 to the second load 92 via the bypass relay 31. Therefore, as shown by the solid line in FIG. 8E, the voltage supplied to the second load 92 is lower than the first voltage E1, but the voltage of the first power supply 11 is maintained and does not become zero. After that, as shown in FIG. 8 (c), when the voltage of the first power supply 11 is restored, the voltage supplied to the second load 92 is also restored as shown in FIG. 8 (e). Therefore, as long as the voltage of the first power supply 11 does not fall below the second voltage E2 between the second time point t2 and the third time point t3, the second load 92 does not fail.

According to the present embodiment, as described above, even when the second path 42 is disconnected and the voltage from the first path 41 is lower than the first voltage E1, the first power supply 11 to the second load 92. Power supply can be secured. Therefore, it is possible to prevent the second load 92 from failing.

[Second Embodiment]
Next, the second embodiment will be described. In the following embodiments, the same or corresponding members as those in the previous embodiments are designated by the same reference numerals. However, the power supply device itself is designated by a different reference numeral for each embodiment. The present embodiment will be described based on the first embodiment and focusing on the differences from the first embodiment.

FIG. 9 is a circuit diagram showing the power supply device 62 of the second embodiment. The power supply device 62 is not provided with the first power supply path 51 and the second power supply path 52. The first path 41 electrically connects the first power supply 11 to both the switch control unit 45 and the relay control unit 55. The second path 42 electrically connects the second power supply 12 to both the switch control unit 45 and the relay control unit 55. The relay control unit 55 can transmit a command to the bypass relay 31 on condition that a voltage equal to or higher than the third voltage E3 (for example, 5V) is supplied. The third voltage E3 is smaller than the first voltage E1 (for example, 9V). Further, the third voltage E3 is smaller than the second voltage E2 (for example, 7V) in the present embodiment, but may be larger than the second voltage.

In FIG. 10, when the second path 42 is normal, the switch control unit 45 issues a close command to one switch (first switch 21 in the figure) and an open command to the other switch (second switch 22 in the figure). It is a circuit diagram which shows the state which put out. At this time, the bypass relay 31 opens as in the case of the first embodiment.

FIG. 11 is a circuit diagram showing a case where the second path 42 is disconnected from the state of FIG. At this time, since the diagnostic information i2 acquired from the detection unit 54 by the relay control unit 55 indicates an abnormality in the second path 42, the relay control unit 55 closes the bypass relay 31 based on the diagnostic information i2.

FIG. 12 shows a case where the voltage of the first power supply 11 drops from the state of FIG. 11 and the voltage of the first power supply 11 becomes a voltage lower than the first voltage E1 and equal to or higher than the third voltage E3. Shows. At this time, the switch control unit 45 cannot issue a command to each of the switches 21 and 22 because the voltage to be supplied becomes less than the first voltage E1. Therefore, both switches 21 and 22, which are normally open switches, open.

On the other hand, since the voltage supplied to the relay control unit 55 is the third voltage E3 or higher, the relay control unit 55 can issue a command to the relay control unit 55. Therefore, the normally closed bypass relay 31 does not close based on the fact that the relay control unit 55 cannot issue a command. However, at this time, the relay control unit 55 has already closed the bypass relay 31 based on the diagnostic information i2. Therefore, the power supply from the first power supply 11 to the second load 92 can be secured by the bypass relay 31.

According to the present embodiment, as described above, even when the second path 42 is disconnected and the voltage from the first path 41 becomes a voltage less than the first voltage E1 and a voltage equal to or higher than the third voltage E3, the first voltage is obtained. It is possible to secure the power supply from the 1 power supply 11 to the second load 92.

[Third Embodiment]
Next, the third embodiment will be described. The present embodiment will be described based on the first embodiment and focusing on the differences from the first embodiment.

FIG. 13 is a circuit diagram showing the power supply device 63 of the third embodiment. The power supply device 63 further has a third switch 34 on the second path 42 and a control unit 33 for controlling the third switch 34. The third switch 34 opens when it receives an open command from the control unit 33, and closes when it receives a close command. The third switch 34 is a normally open type that opens when neither an open signal nor a closed signal is received.

The control unit 33 transmits a close command to the third switch 34 when the start switch 75 of the power unit for traveling the vehicle is turned on, and sends an open command to the third switch 34 when the start switch 75 is turned off.

According to the present embodiment, since the third switch 34 is opened during the start-off period of the power device, it is possible to suppress the flow of dark current from the second power supply 12 to the switch control unit 45. Further, the second path 42 provided with such a third switch 34 is abnormal due to an abnormality caused by the third switch 34 or an abnormality at the connection portion between the third switch 34 and the wiring. Is likely to occur. By targeting such a location for detection by the detection unit 54, an abnormality can be detected more efficiently.

[Other embodiments]
This embodiment can be modified and implemented as follows, for example. Contrary to each embodiment, the first power source 11 may be a lithium battery and the second power source 12 may be a lead battery. Further, the power unit may be a motor or a hybrid of an engine and a motor.

Further, each switch 21, 22, 34 is not a normally open type, and may maintain the current state (open state or closed state) when there is no command. Further, the bypass relay 31 may be a normally open type instead of a normally closed type, or one that maintains the current state when there is no command.

Further, in the first and third embodiments, one of the first feeding path 51 and the second feeding path 52 may be eliminated and only the other may be used. Further, in the third embodiment, the third switch 34 may be provided in the first path 41.

Further, the second load 92 may not include a load that causes a failure if the voltage supplied is less than the second voltage E2. Even in such a case, it is possible to prevent the power supply to the second load 92 from being interrupted.

Further, the detection unit 54 may determine the abnormality of the first path 41 instead of the second path 42. Further, the detection unit 54 detects an abnormality in both the first path 41 and the second path 42, and the relay control unit 55 has an abnormality in at least one of the first path 41 and the second path 42. If detected, the bypass relay 31 may be closed.

In each circuit diagram, the detection unit 54 is a diagram for detecting an abnormality in the plus side path in the second path 42, but of course, an abnormality in both the plus side and the minus side (GND side) is detected. It can be detected, or only the abnormality of the negative route can be detected.

11 ... 1st power supply, 12 ... 2nd power supply, 21 ... 1st switch, 31 ... Bypass relay, 41 ... 1st path, 42 ... 2nd path, 45 ... Switch control unit, 54 ... Detection unit, 55 ... Relay control Unit, 61-63 ... Power supply device, 92 ... Second load 92, E1 ... First voltage.

Claims (6)

A first switch (21) other than the normally closed type that electrically connects and disconnects the first power supply (11) and the second power supply (12) from the first power supply and the predetermined load (92). It is possible to issue a command to the first switch on condition that a bypass relay (31) provided in parallel with the first switch and a voltage equal to or higher than a predetermined required voltage (E1) are supplied. It has a switch control unit (45) and a relay control unit (55) that controls the bypass relay.
A first path (41) for electrically connecting the first power supply to the switch control unit, a second path (42) for electrically connecting the second power supply to the switch control unit, and the first path. And a detection unit (54) for detecting an abnormality of at least one of the second paths.
The relay control unit is a power supply device that closes the bypass relay when the detection unit detects the abnormality. The first switch is a normally open type switch.
Further, it has a normally open type second switch (22) that electrically connects and disconnects the second power supply and the predetermined load.
The switch control unit can issue a command to each of the first switch and the second switch on condition that a voltage higher than the required voltage is supplied.
The relay control unit acquires command information, which is information related to commands for each switch, from the switch control unit.
The relay control unit closes the bypass relay on condition that the command to each switch is an open command in the command information while the abnormality is not detected by the detection unit.
The power supply device according to claim 1. The bypass relay is a normally closed type relay.
The relay control unit is fed from a path (51, 52) that does not pass through either the first path or the second path.
The power supply device according to claim 1 or 2. The bypass relay is a normally closed type relay.
The relay control unit can perform the control of the bypass relay on condition that a voltage equal to or higher than a predetermined voltage (E3) smaller than the required voltage (E1) is supplied. Power is supplied from the first path and the second path.
The power supply device according to claim 1 or 2. The predetermined load according to any one of claims 1 to 4, wherein the predetermined load causes a failure when the voltage to be supplied becomes less than the second required voltage (E2) smaller than the required voltage (E1). Power supply. A third switch (34) is provided in at least one of the first path and the second path, and the detection unit detects an abnormality in the path provided with at least the third switch. 5. The power supply device according to any one of 5.

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