Power source monitoring device

Abstract

A power source monitoring device (1A) is characterized by comprising: a power source unit (11-1); control units (12-1, 12-2) that operate with power supplied from the power source unit (11-1); a switching unit (13-1) that, in response to switching requests output by the control units (12-1, 12-2), performs switching control for switching between a conduction state in which the power source unit (11-1) supplies power to each of the control units (12-1, 12-2) and a cutoff state in which the supply of power is cut off; a switching unit (13-2) that is connected in parallel with the switching unit (13-1), and performs switching control for switching between the conduction state and the cutoff state in response to the switching requests output by the control units (12-1, 12-2); a mask unit (14-1) that disables the switching control by the switching unit (13-1) in response to a first mask request output by the control unit (12-1); and a mask unit (14-2) that disables the switching control by the switching unit (13-2) in response to a second mask request output by the control unit (12-2).

Description

power monitoring device

[0001] The present disclosure relates to a power supply monitoring device that monitors abnormalities in power supply from a power supply unit.

[0002] Some control devices, such as programmable logic controllers (PLCs), that incorporate a control unit such as a central processing unit (CPU) have redundant control units to provide users with higher safety. By providing redundant control units, safe operation can be maintained even if one control unit malfunctions, and the malfunctioning control unit can be safely shut down. Power supply monitoring functions are also provided that monitor the power supplied to the control unit, detect an abnormality, and cut off the power supply to the control unit. In addition to the power supply monitoring function, some devices also have a diagnostic function to ensure that the function is operating normally.

[0003] For example, Patent Document 1 discloses a technology in which the power supply path is divided into two, the CPU circuit, the power cutoff circuit, and the power monitoring circuit are configured to be redundant, and the power monitoring function is diagnosed to ensure that it is operating normally.

[0004] Japanese Patent Application Laid-Open No. 2020-021308

[0005] However, with the above-described conventional technology, the power supply to one of the redundant control units is cut off during the diagnosis, causing that control unit to stop. Once the diagnosis is complete, power is supplied again to restart the device, but this takes time. As a result, the redundant configuration of the control units is not maintained during the diagnosis, which compromises the safety of the device with redundant control units and hinders high-speed information processing by the control units.

[0006] The present disclosure has been made in consideration of the above, and aims to provide a power supply monitoring device that can maintain the safety of a redundant control unit and continue high-speed information processing when diagnosing that the power supply monitoring function for a redundant control unit is operating normally.

[0007] In order to solve the above-mentioned problems and achieve the object, the power supply monitoring device of the present disclosure is characterized by comprising: a first power supply unit that supplies power; a first control unit that operates with power supplied from the first power supply unit; a second control unit that operates with power supplied from the first power supply unit; a first switching unit that performs switching control to switch between a conductive state in which power is supplied from the first power supply unit to each of the first control unit and the second control unit and a cut-off state in which the supply of power is cut off in response to switching requests output by the first control unit and the second control unit; a second switching unit that is connected in parallel with the first switching unit and performs switching control to switch between the conductive state and the cut-off state in response to switching requests output by the first control unit and the second control unit; a first masking unit that disables switching control from the conductive state to the cut-off state by the first switching unit in response to a first masking request output by the first control unit; and a second masking unit that disables switching control from the conductive state to the cut-off state by the second switching unit in response to a second masking request output by the second control unit.

[0008] The power supply monitoring device of the present invention has the advantage that, when diagnosing that the power supply monitoring function for a redundant control unit is operating normally, it is possible to maintain the safety of the redundant control unit and continue high-speed information processing.

[0009] FIG. 1 is a diagram showing the functional configuration of a power supply monitoring device according to a first embodiment. FIG. 2 is a diagram showing an example of a hardware configuration of the power supply monitoring device shown in FIG. 1. FIG. 3 is a diagram showing the functional configuration of a power supply monitoring device according to a second embodiment. FIG. 4 is a diagram showing an example of a hardware configuration of the power supply monitoring device shown in FIG. 5. FIG. 5 is a diagram showing the functional configuration of a power supply monitoring device according to a fourth embodiment. FIG. 7 is a diagram showing the functional configuration of a power supply monitoring device according to a fifth embodiment. FIG. 9 is a diagram showing an example of a hardware configuration of a power supply monitoring device according to a sixth embodiment. FIG. 7 is a diagram showing an example of a hardware configuration of a power supply monitoring device according to a seventh embodiment. FIG. 8 is a diagram showing an example of a hardware configuration of a power supply monitoring device according to a ninth embodiment. FIG. 10 is a diagram showing an example of a hardware configuration of a power supply monitoring device according to an eleventh embodiment. FIG. 12 is a diagram showing an example of a hardware configuration of a power supply monitoring device according to a twelfth embodiment.

[0010] A power supply monitoring device according to an embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0011] 1 is a diagram showing the functional configuration of a power supply monitoring device 1A according to embodiment 1. The power supply monitoring device 1A has a power supply unit 11-1, control units 12-1 and 12-2, switching units 13-1 and 13-2, and mask units 14-1 and 14-2.

[0012] The power supply unit 11-1 supplies power to the control units 12-1 and 12-2.

[0013] The control units 12-1 and 12-2 are driven by power supplied from the power supply unit 11-1. Details of the control units 12-1 and 12-2 will be described later.

[0014] The switching unit 13-1 is connected to a power supply path between the power supply unit 11-1 and the control units 12-1 and 12-2. The switching unit 13-1 performs switching control to switch between a conductive state in which power is supplied from the power supply unit 11-1 to each of the control units 12-1 and 12-2 and a cut-off state in which the supply of power is cut off. The function of switching control performed by the switching unit 13-1 is referred to as a first cut-off function. The switching unit 13-1 can switch between the conductive state and the cut-off state in response to a switching request requesting switching between the conductive state and the cut-off state. In the present embodiment, the switching unit 13-1 switches between the conductive state and the cut-off state in response to a first cut-off request or a second cut-off request, which are examples of a switching request.

[0015] The switching unit 13-2 is connected in parallel to the switching unit 13-1 to a power supply path between the power supply unit 11-1 and the control units 12-1 and 12-2. The switching unit 13-2 performs switching control to switch between a conductive state in which power is supplied from the power supply unit 11-1 to each of the control units 12-1 and 12-2 and a cut-off state in which the supply of power is cut off. The switching control function performed by the switching unit 13-2 is referred to as a second cut-off function. The switching unit 13-2 can switch between the conductive state and the cut-off state in response to a switching request. In this embodiment, the switching unit 13-2 switches between the conductive state and the cut-off state in response to a first cut-off request or a second cut-off request, which are examples of a switching request.

[0016] The mask unit 14-1 can disable the switching control from the conduction state to the cutoff state by the switching unit 13-1 in response to the first mask request output by the control unit 12-1. The mask unit 14-1 is provided on a path that transmits the first cutoff request and the second cutoff request output by the control units 12-1 and 12-2 to the switching unit 13-1. The mask unit 14-1 has a first mask function that can switch between a conduction state in which the first cutoff request and the second cutoff request output by the control units 12-1 and 12-2 are transmitted to the switching unit 13-1 and a cutoff state in which the first cutoff request and the second cutoff request are cut off. When the mask unit 14-1 cuts off the first cutoff request and the second cutoff request, even if the control units 12-1 and 12-2 output the first cutoff request and the second cutoff request, they are not transmitted to the switching unit 13-1, and therefore the switching control by the switching unit 13-1 is disabled.

[0017] The mask unit 14-2 can disable the switching control from the conduction state to the cutoff state by the switching unit 13-2 in response to the second mask request output by the control unit 12-2. The mask unit 14-2 is provided on a path that transmits the first cutoff request and the second cutoff request output by the control units 12-1 and 12-2 to the switching unit 13-2. The mask unit 14-2 has a second mask function that can switch between a conduction state in which the first cutoff request and the second cutoff request output by the control units 12-1 and 12-2 are transmitted to the switching unit 13-2 and a cutoff state in which the first cutoff request and the second cutoff request are cut off. When the mask unit 14-2 cuts off the first cutoff request and the second cutoff request, even if the control units 12-1 and 12-2 output the first cutoff request and the second cutoff request, they are not transmitted to the switching unit 13-2, and therefore the switching control by the switching unit 13-2 is disabled.

[0018] Here, the details of the control units 12-1 and 12-2 will be described. The control unit 12-1 has a shutdown request function 121-1, which is a function that can output a first shutdown request that requests that the switching units 13-1 and 13-2 be switched between a conductive state and a cut-off state. The control unit 12-1 also has a mask request function 122-1, which is a function that can output a first mask request that requests that the first shutdown request transmitted from the control unit 12-1 to the switching unit 13-1 and the second shutdown request transmitted from the control unit 12-2 to the switching unit 13-1 be made conductive and cut-off. The first mask request can also be said to request that the switching control by the switching unit 13-1 be disabled.

[0019] The control unit 12-2 also has a cutoff request function 121-2 that is a function that can output a second cutoff request that requests switching between the conductive state and the cutoff state of the switching units 13-1 and 13-2. The control unit 12-2 also has a mask request function 122-2 that is a function that can output a second mask request that requests the first cutoff request transmitted from the control unit 12-1 to the switching unit 13-2 and the second cutoff request transmitted from the control unit 12-2 to the switching unit 13-2 to be made conductive and cutoff. The second mask request can also be said to request that the switching control by the switching unit 13-2 be disabled.

[0020] The control units 12-1 and 12-2 can cut off the power supply from the power supply unit 11-1 using the cut-off request functions 121-1 and 121-2, and can also use the cut-off request function 121-1 and the mask request function 122-1, or the cut-off request function 121-2 and the mask request function 122-2, to cut off only one of the switching units 13-1 and 13-2 while maintaining the power supply.

[0021] When cutting off the power supply to switching units 13-1 and 13-2, control unit 12-1 outputs a first cut-off request or control unit 12-2 outputs a second cut-off request, which causes the first cut-off function of switching unit 13-1 and the second cut-off function of switching unit 13-2 to function and transitions switching units 13-1 and 13-2 to a cut-off state.

[0022] When only switching unit 13-2 is to be shut off while maintaining power supply to control units 12-1 and 12-2, first, control unit 12-1 outputs a first mask request to mask unit 14-1. This causes mask unit 14-1 to transition to a shut-off state, disabling the switching control of switching unit 13-1. In this state, control unit 12-1 outputs a first shut-off request. This prevents the first shut-off request from being transmitted to switching unit 13-1, and only switching unit 13-2 transitions to the shut-off state in response to the first shut-off request. At this time, switching unit 13-2 is in a shut-off state and switching unit 13-1 is in a conductive state, so power supply to control units 12-1 and 12-2 is maintained via switching unit 13-1.

[0023] When only switching unit 13-1 is shut off while maintaining power supply to control units 12-1 and 12-2, similar to the case of shutting off only switching unit 13-2 described above, control unit 12-2 first outputs a second mask request to mask unit 14-2. This causes mask unit 14-2 to transition to the cut-off state, and the switching control of switching unit 13-2 is disabled. In this state, control unit 12-2 outputs a second cut-off request. This prevents the second cut-off request from being transmitted to switching unit 13-2, and only switching unit 13-1 transitions to the cut-off state in response to the second cut-off request. At this time, switching unit 13-1 is in the cut-off state and switching unit 13-2 is in the conductive state, so power supply to control units 12-1 and 12-2 is maintained via switching unit 13-2.

[0024] Furthermore, various states can be realized by combining the connections of each request. For example, it is possible to shut down only the switching unit 13-2 in response to a first mask request from the control unit 12-1 and a second shut-down request from the control unit 12-2, and it is also possible to shut down only the switching unit 13-1 in response to a second mask request from the control unit 12-2 and a first shut-down request from the control unit 12-1.

[0025] If any of the control units 12-1, 12-2 or the mask units 14-1, 14-2 malfunctions, resulting in an unstable situation where the intended operation cannot be performed, both of the switching units 13-1, 13-2 will be shut off in any of the operations based on the combination of the above-mentioned requests, thereby making it possible to improve the reliability of the power supply monitoring device 1A and the control equipment that incorporates the power supply monitoring device 1A.

[0026] Fig. 2 is a diagram showing an example of the hardware configuration of the power supply monitoring device 1A shown in Fig. 1. As shown in Fig. 2, the power supply monitoring device 1A is realized using a power supply circuit 91-1, control circuits 92-1 and 92-2, shutoff circuits 93-1 and 93-2, power supply monitoring circuits 94-1 and 94-2, mask circuits 95-1 and 95-2, and peripheral circuits 96-1 and 96-2.

[0027] The power supply circuit 91-1 is, for example, a DC stabilized power supply device installed outside the control device to supply power to the control device, a linear regulator circuit that reduces the voltage supplied from the DC stabilized power supply device, a switching regulator circuit that increases or decreases the voltage, an AC power supply installed outside the control device, or the like.

[0028] The control circuits 92-1 and 92-2 are, for example, circuits realized by a microcomputer, elements such as an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a logic IC (Integrated Circuit) that drives an output circuit with a predetermined logic in response to an external input.

[0029] The cutoff circuits 93-1 and 93-2 are realized by switches configured with, for example, field effect transistors (MOSFETs), and are circuits that can control switching between a conductive state and a cutoff state by controlling the gate voltage from the outside.

[0030] The power supply monitoring circuits 94-1 and 94-2 are, for example, power supply monitoring ICs, and are voltage comparison circuits such as circuits that have terminals that identify overvoltage and undervoltage conditions by comparing the voltage of the monitored object with an arbitrarily determined reference voltage, and that can output a signal that can distinguish the result of voltage monitoring by using two values, an H level or an L level voltage signal.

[0031] The mask circuits 95-1 and 95-2 are realized, for example, by open-drain connection of MOSFETs, and output a signal that can distinguish the first shut-off request from the control circuit 92-1 based on the binary value of the voltage signal, either H level or L level, and output a signal that can distinguish the second shut-off request from the control circuit 92-2 based on the binary value of the voltage signal, either H level or L level.By controlling the gate voltage from the outside, the output signals indicating the first shut-off request and the second shut-off request are forcibly set to L level, thereby masking the first shut-off request and the second shut-off request and preventing them from being output to the shut-off circuits 93-1 and 93-2, and disabling the switching control of the shut-off circuits 93-1 and 93-2.

[0032] The peripheral circuits 96-1 and 96-2 are, for example, memory circuits, and are circuits that assist the functions of the control circuits 92-1 and 92-2 by communicating with them, respectively.

[0033] The power output from power supply circuit 91-1 is input to shutoff circuits 93-1 and 93-2. When shutoff circuits 93-1 and 93-2 are in a conductive state, they supply power from power supply circuit 91-1 to control circuits 92-1 and 92-2, respectively, and when shutoff circuits 93-1 and 93-2 are in a cutoff state, the power supply is cut off at shutoff circuits 93-1 and 93-2 that are in the cutoff state. Because shutoff circuits 93-1 and 93-2 are connected in parallel, power is supplied to control circuits 92-1 and 92-2 when at least one of shutoff circuits 93-1 and 93-2 is in a conductive state.

[0034] The control circuit 92-1 has a shutdown request function 921-1, and can arbitrarily control and output the voltage monitoring results of the power supply monitoring circuit 94-2 using a first shutdown request. This can be achieved, for example, by controlling the enable of the IC of the power supply monitoring circuit 94-2, or by changing the voltage division ratio of the power supply that is monitored by dividing it using a resistor and inputting it, by turning on a MOSFET. Upon receiving the first shutdown request from the control circuit 92-1, the power supply monitoring circuit 94-2 recognizes an overvoltage or undervoltage state and can communicate the first shutdown request to the shutdown circuits 93-1 and 93-2. This allows the shutdown circuits 93-1 and 93-2 to transition their switches to the shutdown state.

[0035] The control circuit 92-2 has a shutdown request function 921-2, and can arbitrarily control and output the voltage monitoring results of the power supply monitoring circuit 94-1 using a second shutdown request. This can be achieved, for example, by controlling the enable of the IC of the power supply monitoring circuit 94-1, or by changing the voltage division ratio of the power supply that is monitored by dividing it using a resistor and inputting it, by turning on a MOSFET. Upon receiving the second shutdown request from the control circuit 92-2, the power supply monitoring circuit 94-1 recognizes an overvoltage or undervoltage state and can communicate the second shutdown request to the shutdown circuits 93-1 and 93-2. This allows the shutdown circuits 93-1 and 93-2 to transition their switches to the shutdown state.

[0036] The control circuit 92-1 has a mask request function 922-1, and can shut off a second shutoff request signal communicated from the control circuit 92-2 to the shutoff circuit 93-1 via the power supply monitoring circuit 94-1 or a first shutoff request signal communicated from the control circuit 92-1 to the shutoff circuit 93-1 via the power supply monitoring circuit 94-2 by operating the mask circuit 95-1. This makes it possible to selectively prevent the shutoff circuit 93-1 from transitioning to the shutoff state in response to the first shutoff request or second shutoff request communicated from the control circuit 92-1 or the control circuit 92-2.

[0037] The control circuit 92-2 has a mask request function 922-2, and can shut off a first shutoff request signal communicated from the control circuit 92-1 to the shutoff circuit 93-2 via the power supply monitoring circuit 94-2 or a second shutoff request signal communicated from the control circuit 92-2 to the shutoff circuit 93-2 via the power supply monitoring circuit 94-1 by operating the mask circuit 95-2. This makes it possible to selectively prevent the shutoff circuit 93-2 from transitioning to the shutoff state in response to the first shutoff request or the second shutoff request communicated from the control circuit 92-1 or the control circuit 92-2.

[0038] The control circuit 92-1 has a communication function 923-1 and communicates with the peripheral circuit 96-1, and the control circuit 92-2 has a communication function 923-2 and communicates with the peripheral circuit 96-2.

[0039] As described above, by using a circuit having a configuration such as that shown in FIG. 2, it is possible to realize a power supply monitoring device 1A having the functions shown in FIG.

[0040] As described above, the power supply monitoring device 1A according to the first embodiment includes a power supply unit 11-1 which is a first power supply unit that supplies power, a control unit 12-1 which is a first control unit that operates on power supplied from the power supply unit 11-1, a control unit 12-2 which is a second control unit that operates on power supplied from the power supply unit 11-1, a switching unit 13-1 which is a first switching unit that performs switching control to switch between a conduction state in which power is supplied from the power supply unit 11-1 to the control units 12-1 and 12-2 and a cut-off state in which the supply of power is cut off in response to a first cut-off request and a second cut-off request that are switch requests output by the control units 12-1 and 12-2, and a switching unit 13- The power supply control unit 11-1 is characterized by including: a switching unit 13-2, which is a second switching unit connected in parallel with the power supply control unit 11-1 and performs switching control between a conductive state in which power is supplied from the power supply unit 11-1 to the control units 12-1 and 12-2 and a cut-off state in which the power supply is cut off, in response to a first cut-off request and a second cut-off request output by the control units 12-1 and 12-2; a masking unit 14-1, which is a first masking unit that disables the switching control by the switching unit 13-1 in response to a first masking request output by the control unit 12-1; and a masking unit 14-2, which is a second masking unit that disables the switching control by the switching unit 13-2 in response to a second masking request output by the control unit 12-2. According to the above configuration, the redundant switching units 13-1 and 13-2 can be individually transitioned to the cut-off state while maintaining power supply to the control units 12-1 and 12-2. This allows the power supply monitoring function to be diagnosed without interfering with the information processing of the control units 12-1 and 12-2. If an overvoltage or undervoltage state is detected in the monitored object, power to the monitored object is promptly shut off after diagnosis.

[0041] Second Embodiment. Figure 3 is a diagram showing the functional configuration of a power supply monitoring device 1B according to a second embodiment. The power supply monitoring device 1B has a power supply unit 11-1, control units 12B-1 and 12B-2, switching units 13-1 and 13-2, masking units 14-1 and 14-2, and shutdown confirmation units 15-1 and 15-2. In addition to the configuration of the power supply monitoring device 1A according to the first embodiment, the power supply monitoring device 1B also has shutdown confirmation units 15-1 and 15-2, and has control units 12B-1 and 12B-2 instead of the control units 12-1 and 12-2 of the power supply monitoring device 1A. The following mainly describes the differences from the power supply monitoring device 1A.

[0042] The cutoff confirmation unit 15-1 is connected to the subsequent stage of the switching unit 13-1 in the power supply path via the switching unit 13-1. The power supply path branches off at the subsequent stage of the cutoff confirmation unit 15-1 to supply power to each of the control units 12B-1 and 12B-2.

[0043] The cutoff confirmation unit 15-2 is connected to the rear stage of the switching unit 13-2 in the power supply path via the switching unit 13-2, and is connected so that the combination with the switching unit 13-2 is in parallel with the combination of the switching unit 13-1 and the cutoff confirmation unit 15-1.

[0044] The interruption confirmation unit 15-1 has a first interruption notification function, which is a function that can identify whether the switching unit 13-1 is in a conductive state or a cut-off state and output first state information indicating whether the switching unit 13-1 is in a conductive state or a cut-off state.

[0045] The interruption confirmation unit 15-2 has a second interruption notification function, which is a function that can identify whether the switching unit 13-2 is in a conductive state or a cut-off state and output second state information indicating whether the switching unit 13-2 is in a conductive state or a cut-off state.

[0046] The control unit 12B-1 has an interruption determination function 123-1 in addition to the functions of the control unit 12-1. The interruption determination function 123-1 is a function that receives first state information output from the interruption confirmation unit 15-1, determines whether the switching unit 13-1 is in a conductive state or an interrupted state, and is capable of sharing the determination result with the control unit 12B-2 via communication.

[0047] The control unit 12B-2 has an interruption determination function 123-2 in addition to the functions of the control unit 12-2. The interruption determination function 123-2 is a function that receives second state information output from the interruption confirmation unit 15-2, determines whether the switching unit 13-2 is in a conductive state or an interrupted state, and is capable of sharing the determination result with the control unit 12B-1 through communication.

[0048] After the switching units 13-1 and 13-2 are controlled using the shutdown request function 121-1 of the control unit 12B-1 or the shutdown request function 121-2 of the control unit 12B-2, the control unit 12B-1 receives first status information from the shutdown confirmation unit 15-1 using the shutdown determination function 123-1, thereby being able to determine the actual status of the switching unit 13-1 and share the determination result with the control unit 12B-2 via communication.

[0049] Similarly, after the switching units 13-1 and 13-2 are controlled using the shutdown request function 121-1 of the control unit 12B-1 or the shutdown request function 121-2 of the control unit 12B-2, the control unit 12B-2 receives second status information from the shutdown confirmation unit 15-2 using the shutdown determination function 123-2, thereby being able to determine the actual status of the switching unit 13-2 and share the determination result with the control unit 12B-1 via communication.

[0050] As described above, according to the second embodiment, a series of shutdown requests initiated by the control unit 12B-1 can be received and determined by the control unit 12B-2 as the result of the shutdown. This allows the means that executed the shutdown and the means that determined the shutdown to be efficiently separated, making it possible to ensure safety with high reliability. If the control unit that requests and executes the diagnosis and the control unit that determines the diagnosis result are the same, an accurate diagnosis may not be possible if the control unit that requests, executes, and determines the diagnosis itself is abnormal. In contrast, the above configuration can increase the reliability of the diagnosis.

[0051] Fig. 4 is a diagram showing an example of the hardware configuration of the power supply monitoring device 1B shown in Fig. 3. As shown in Fig. 4, the power supply monitoring device 1B is realized using a power supply circuit 91-1, control circuits 92-B1 and 92B-2, shutdown circuits 93-1 and 93-2, power supply monitoring circuits 94-1 and 94-2, mask circuits 95-1 and 95-2, peripheral circuits 96-1 and 96-2, and shutdown confirmation circuits 97-1 and 97-2. The following mainly describes the parts that are different from the circuit shown in Fig. 2.

[0052] The interruption confirmation circuit 97-1 is connected to the subsequent stage of the interruption circuit 93-1. The interruption confirmation circuit 97-2 is connected to the subsequent stage of the interruption circuit 93-2. The combination of the interruption circuit 93-2 and the interruption confirmation circuit 97-2 is connected in parallel with the combination of the interruption circuit 93-1 and the interruption confirmation circuit 97-1.

[0053] The shutdown confirmation circuit 97-1 is realized by a rectifier such as a diode, and is a circuit that can output the voltage between the shutdown circuit 93-1 and the shutdown confirmation circuit 97-1 as an H level when the shutdown circuit 93-1 connected in the preceding stage is in a conductive state, and as an L level when the shutdown circuit 93-1 is in a shutdown state.

[0054] The shutdown confirmation circuit 97-2 is realized by a rectifier such as a diode, and is a circuit that can output the voltage between the shutdown circuit 93-2 and the shutdown confirmation circuit 97-2 as an H level when the shutdown circuit 93-2 connected in the preceding stage is in a conductive state, and as an L level when the shutdown circuit 93-2 is in a shutdown state.

[0055] The control circuit 92B-1 has an interruption determination function 924-1 in addition to the functions of the control circuit 92-1. The control circuit 92B-1 can receive the first state information output from the interruption confirmation circuit 97-1 and determine whether the interruption circuit 93-1 is in a conductive state or an interrupted state, and can share the determination result with the control circuit 92B-2 by communicating with it.

[0056] The control circuit 92B-2 has an interruption determination function 924-2 in addition to the functions of the control circuit 92-2. The control circuit 92B-2 can receive second state information output from the interruption confirmation circuit 97-2 and determine whether the interruption circuit 93-2 is in a conductive state or an interrupted state, and can share the determination results with the control circuit 92B-1 by communicating with it.

[0057] As described above, power supply monitoring device 1B according to the second embodiment further includes, in addition to power supply monitoring device 1A, shutdown confirmation unit 15-1, which is a first shutdown confirmation unit capable of transmitting first status information indicating whether switching unit 13-1, which is a first switching unit, is in a conductive state or a cut-off state, and shutdown confirmation unit 15-2, which is a second shutdown confirmation unit capable of transmitting second status information indicating whether switching unit 13-2, which is a second switching unit, is in a conductive state or a cut-off state. Control unit 12B-1, which is a first control unit, has shutdown determination function 123-1, which is a first shutdown determination function, capable of receiving the first status information and sharing the received first status information with control unit 12B-2, which is a second control unit, through communication, and control unit 12B-2 has shutdown determination function 123-2, which is a second shutdown determination function, capable of receiving second status information and sharing the received second status information with control unit 12B-1 through communication.

[0058] Third Embodiment Figure 5 is a diagram showing the functional configuration of a power supply monitoring device 1C according to a third embodiment. The power supply monitoring device 1C has a power supply unit 11-1, control units 12-1 and 12-2, switching units 13-1, 13-2 and 13-3, and masking units 14-1 and 14-2. In addition to the components of the power supply monitoring device 1A according to the first embodiment, the power supply monitoring device 1C also has a switching unit 13-3. The following mainly describes the differences from the power supply monitoring device 1A.

[0059] The switching unit 13-3 is inserted in the power supply path between the power supply unit 11-1 and the switching units 13-1 and 13-2 connected in parallel.

[0060] The switching unit 13-3 has a function of monitoring the state of the power supply path from the power supply unit 11-1 to the control units 12-1 and 12-2 and of switching between conduction and interruption.

[0061] The switching unit 13-3 makes the first cut-off function of the switching unit 13-1 and the second cut-off function of the switching unit 13-2 redundant in one functional unit, and even if the power supply cannot be cut off due to a failure of one or both functional units, by setting the switching unit 13-3 to a cut-off state, it is possible to cut off both the power supply path via the switching unit 13-1 and the power supply path via the switching unit 13-2.

[0062] Fig. 6 is a diagram showing an example of the hardware configuration of the power supply monitoring device 1C shown in Fig. 5. As shown in Fig. 6, the power supply monitoring device 1C is realized using a power supply circuit 91-1, control circuits 92-1 and 92-2, shutoff circuits 93-1, 93-2, and 93-3, power supply monitoring circuits 94-1, 94-2, and 94-3, mask circuits 95-1 and 95-2, and peripheral circuits 96-1 and 96-2. The following mainly describes the parts that differ from the circuit shown in Fig. 2.

[0063] The cutoff circuit 93-3 is realized by a switch configured with, for example, a MOSFET, and is a circuit that can control switching between a conductive state and a cutoff state by controlling the gate voltage from the outside.

[0064] The power supply monitoring circuit 94-3 is, for example, a power supply monitoring IC, and is a voltage comparison circuit such as a circuit that has a terminal that identifies overvoltage and undervoltage conditions by comparing the voltage of the monitored object with an arbitrarily determined reference voltage, and that can output a signal that can distinguish the result of voltage monitoring by using two values ​​of the voltage signal: H level and L level.

[0065] When the power supply monitoring circuit 94-3 detects an abnormality in the power supply path between the power supply circuit 91-1 and the cut-off circuit 93-3, it outputs a signal to the cut-off circuit 93-3 to determine the abnormality, thereby transitioning the cut-off circuit 93-3 to a cut-off state and preventing the supply of abnormal power.

[0066] As described above, the power supply monitoring device 1C according to the third embodiment is characterized in that, in addition to the configuration of the power supply monitoring device 1A, it further includes a third switching unit, switching unit 13-3, which is connected to the power supply path between power supply unit 11-1 and switching units 13-1 and 13-2 and performs switching control to switch between a conductive state in which power is supplied from power supply unit 11-1 to each of control units 12-1 and 12-2 and a cut-off state in which power is cut off. This makes the cut-off function redundant, so that even if an abnormality occurs in the power supply, it is possible to more reliably cut off the power supply path to control units 12-1 and 12-2, thereby improving the safety of the power supply monitoring device 1C.

[0067] Fourth Embodiment. Figure 7 is a diagram showing the functional configuration of a power supply monitoring device 1D according to a fourth embodiment. The power supply monitoring device 1D has power supply units 11-1, 11-2, and 11-3, control units 12-1 and 12-2, switching units 13-1 and 13-2, mask units 14-1 and 14-2, and monitoring units 16-1 and 16-2. In addition to the configuration of the power supply monitoring device 1A according to the first embodiment, the power supply monitoring device 1D further has power supply units 11-2 and 11-3 and monitoring units 16-1 and 16-2. The following mainly describes the differences from the power supply monitoring device 1A.

[0068] The power supply unit 11-2 receives power supplied from the power supply unit 11-1, controls the voltage and current of the power, and supplies the power to the control unit 12-1.

[0069] The power supply unit 11-3 receives power supplied from the power supply unit 11-1, controls the voltage and current of the power, and supplies the power to the control unit 12-2.

[0070] The monitoring unit 16-1 is inserted in the power supply path from the power supply unit 11-2 to the control unit 12-1, and has the function of monitoring the state of the power supply path and outputting the monitoring result. The monitoring unit 16-1 can monitor, for example, a first voltage which is the voltage of the power supply path between the power supply unit 11-2 and the control unit 12-1, and output a third shut-off request to the switching units 13-1 and 13-2 based on the first voltage, and can also relay a second shut-off request output by the control unit 12-2 and output it to the switching units 13-1 and 13-2.

[0071] The monitoring unit 16-2 is inserted in the power supply path from the power supply unit 11-3 to the control unit 12-2, and has the function of monitoring the state of the power supply path and outputting the monitoring result. The monitoring unit 16-2 can monitor, for example, a second voltage which is the voltage of the power supply path between the power supply unit 11-3 and the control unit 12-2, and output a fourth shut-off request to the switching units 13-1 and 13-2 based on the second voltage, and can also relay the first shut-off request output by the control unit 12-1 and output it to the switching units 13-1 and 13-2.

[0072] When the monitoring units 16-1 and 16-2 output the first to fourth shutdown requests to the switching units 13-1 and 13-2, the requests are output via the masking units 14-1 and 14-2.

[0073] Fig. 8 is a diagram showing an example of the hardware configuration of the power supply monitoring device 1D shown in Fig. 7. As shown in Fig. 8, the power supply monitoring device 1D is realized using power supply circuits 91-1, 91-2, and 91-3, control circuits 92-1 and 92-2, shutoff circuits 93-1 and 93-2, power supply monitoring circuits 94-1, 94-2, 94-4, and 94-5, mask circuits 95-1 and 95-2, and peripheral circuits 96-1 and 96-2. The following will mainly explain the differences from the power supply monitoring device 1A.

[0074] The power supply circuits 91-2 and 91-3 are, for example, a linear regulator circuit that steps down the voltage supplied from the power supply circuit 91-1, or a switching regulator circuit that steps up or down the voltage.

[0075] The power supply circuit 91-2 receives power supplied from the power supply circuit 91-1 and supplies controlled power to the control circuit 92-1 and the peripheral circuit 96-1.

[0076] The power supply circuit 91-3 receives power supplied from the power supply circuit 91-1 and supplies controlled power to the control circuit 92-2 and the peripheral circuit 96-2.

[0077] The power supply monitoring circuits 94-4 and 94-5 are, for example, power supply monitoring ICs that have terminals that identify overvoltage and undervoltage states by comparing the monitored voltage with an arbitrarily determined reference voltage, and are circuits that can output a signal that can distinguish the result of the voltage monitoring by using two values, an H level or an L level voltage signal.

[0078] The control circuit 92-1 can arbitrarily control and output the voltage monitoring results of the power supply monitoring circuit 94-5 using a first shutdown request from the shutdown request function 921-1. The power supply monitoring circuit 94-5 can recognize an overvoltage or undervoltage state upon receiving the first shutdown request from the control circuit 92-1 and communicate the first shutdown request to the shutdown circuits 93-1 and 93-2. This allows the shutdown circuits 93-1 and 93-2 to transition their switches to the shutdown state.

[0079] The control circuit 92-2 can arbitrarily control and output the voltage monitoring results of the power supply monitoring circuit 94-4 using a second shutdown request from the shutdown request function 921-2. The power supply monitoring circuit 94-4 can recognize an overvoltage or undervoltage state upon receiving the second shutdown request from the control circuit 92-2 and communicate the second shutdown request to the shutdown circuits 93-1 and 93-2. This allows the shutdown circuits 93-1 and 93-2 to transition their switches to the shutdown state.

[0080] As described above, the power supply monitoring device 1D according to the fourth embodiment includes, in addition to the configuration of the power supply monitoring device 1A, a power supply unit 11-2 which is a second power supply unit connected to the power supply path between the power supply unit 11-1 and the control unit 12-1 and controls the power supplied by the power supply unit 11-1 to supply power to the control unit 12-1, a power supply unit 11-3 which is a third power supply unit connected to the power supply path between the power supply unit 11-1 and the control unit 12-2 and controls the power supplied by the power supply unit 11-1 to supply power to the control unit 12-2, and a power supply unit 11-4 which monitors a first voltage which is the voltage on the power supply path between the power supply unit 11-2 and the control unit 12-1 and calculates a third voltage based on the first voltage. The power supply circuit further includes a monitoring unit 16-1 that is a first monitoring unit capable of outputting a shutdown request to switching units 13-1 and 13-2 and relaying a second shutdown request output by control unit 12-2 to output the request to switching units 13-1 and 13-2, and a monitoring unit 16-2 that is a second monitoring unit capable of monitoring a second voltage that is a voltage of a power supply path between power supply unit 11-3 and control unit 12-2, outputting a fourth shutdown request to switching units 13-1 and 13-2 based on the second voltage, and relaying the first shutdown request output by control unit 12-1 to output the request to switching units 13-1 and 13-2. This makes it possible to monitor the power of each of the multiple power supply paths and to shut down the power supply paths based on the monitoring results.

[0081] Fifth Embodiment. Figure 9 is a diagram showing the functional configuration of a power supply monitoring device 1E according to a fifth embodiment. The power supply monitoring device 1E has power supply units 11-1 and 11-4, control units 12-1 and 12-2, switching units 13-1 and 13-2, mask units 14-1 and 14-2, and monitoring units 16-3 and 16-4. In addition to the configuration of the power supply monitoring device 1A according to the first embodiment, the power supply monitoring device 1E further has a power supply unit 11-4 and monitoring units 16-3 and 16-4. The following mainly describes the differences from the power supply monitoring device 1A.

[0082] The power supply unit 11-4 receives power supplied from the power supply unit 11-1, controls the voltage and current of the power, and supplies the power to the control units 12-1 and 12-2.

[0083] The monitoring unit 16-3 is inserted between the power supply path from the power supply unit 11-4 to the control units 12-1 and 12-2, and has the function of monitoring the state of the power supply path, i.e., the state of the power supplied by the power supply unit 11-4, and outputting the monitoring results. The monitoring unit 16-3 can monitor, for example, a third voltage, which is the voltage of the power supply path between the power supply unit 11-4 and the control units 12-1 and 12-2, and output a fifth shut-off request to the switching units 13-1 and 13-2 based on the third voltage, and can also relay the second shut-off request output by the control unit 12-2 and output it to the switching units 13-1 and 13-2. The monitoring unit 16-3 can output the second shut-off request and the fifth shut-off request to the switching units 13-1 and 13-2 via the mask units 14-1 and 14-2.

[0084] The monitoring unit 16-4 is inserted between the power supply path from the power supply unit 11-4 to the control units 12-1 and 12-2, and has the function of monitoring the state of the power supply path, i.e., the state of the power supplied by the power supply unit 11-4, and outputting the monitoring results. Similar to the monitoring unit 16-3, the monitoring unit 16-4 can monitor the third voltage and output a sixth shutdown request to the switching units 13-1 and 13-2 based on the third voltage. The monitoring unit 16-4 can also relay the first shutdown request output by the control unit 12-1 and output it to the switching units 13-1 and 13-2. The monitoring unit 16-4 can output the first shutdown request and the sixth shutdown request to the switching units 13-1 and 13-2 via the mask units 14-1 and 14-2.

[0085] Fig. 10 is a diagram showing an example of the hardware configuration of the power supply monitoring device 1E shown in Fig. 9. As shown in Fig. 10, the power supply monitoring device 1E is realized using power supply circuits 91-1 and 91-4, control circuits 92-1 and 92-2, shutoff circuits 93-1 and 93-2, power supply monitoring circuits 94-1, 94-2, 94-6, and 94-7, mask circuits 95-1 and 95-2, and peripheral circuits 96-1 and 96-2. The following mainly describes the differences from the power supply monitoring device 1A.

[0086] The power supply circuit 91-4 is, for example, a linear regulator circuit that steps down the voltage supplied from the power supply circuit 91-1, or a switching regulator circuit that steps up or down the voltage.

[0087] The power supply circuit 91-4 receives power supplied from the power supply circuit 91-1 and supplies controlled power to the control circuits 92-1 and 92-2 and the peripheral circuits 96-1 and 96-2.

[0088] The power supply monitoring circuits 94-6 and 94-7 are, for example, power supply monitoring ICs that have terminals that identify overvoltage and undervoltage conditions by comparing the monitored voltage with an arbitrarily determined reference voltage, and are circuits that can output a signal that can distinguish the result of the voltage monitoring by using two values, an H level or an L level voltage signal.

[0089] The control circuit 92-1 can arbitrarily control and output the voltage monitoring result of the power supply monitoring circuit 94-7 using the first shutdown request from the shutdown request function 921-1. Furthermore, the power supply monitoring circuit 94-7 can recognize an overvoltage or undervoltage state upon receiving the first shutdown request from the control circuit 92-1 and communicate the first shutdown request to the shutdown circuits 93-1 and 93-2. This allows the shutdown circuits 93-1 and 93-2 to transition their switches to the shutdown state.

[0090] The control circuit 92-2 can arbitrarily control and output the voltage monitoring result of the power supply monitoring circuit 94-6 using a second shutdown request from the shutdown request function 921-2. Furthermore, the power supply monitoring circuit 94-6 can recognize an overvoltage or undervoltage state upon receiving the second shutdown request from the control circuit 92-2 and communicate the second shutdown request to the shutdown circuits 93-1 and 93-2. This allows the shutdown circuits 93-1 and 93-2 to transition their switches to the shutdown state.

[0091] As described above, power supply monitoring device 1E according to the fifth embodiment has the same configuration as power supply monitoring device 1A, and further includes power supply unit 11-4, which is a fourth power supply unit connected between power supply unit 11-1 and control units 12-1 and 12-2, and which controls the power supplied by power supply unit 11-1 to supply power to control units 12-1 and 12-2; and power supply unit 11-4, which monitors a third voltage, which is the voltage on the power supply path between power supply unit 11-4 and control units 12-1 and 12-2, and issues a fifth shut-off request, which is a switch request, to switching unit 13-1 and switching unit 13-2 based on the third voltage. The power supply circuit further comprises a monitoring unit 16-3 which is a third monitoring unit capable of relaying the second shutoff request output by the control unit 12-2 to the switching unit 13-1 and the switching unit 13-2 and outputting the sixth shutoff request to the switching unit 13-1 and the switching unit 13-2, and a fourth monitoring unit 16-4 which is capable of monitoring the third voltage and outputting a sixth shutoff request, which is a switching request based on the third voltage, to the switching unit 13-1 and the switching unit 13-2 and relaying the first shutoff request output by the control unit 12-1 to output the sixth shutoff request to the switching unit 13-1 and the switching unit 13-2.

[0092] The configurations of the first to fifth embodiments described above can also be used in combination. An example of combining the embodiments will be described below.

[0093] Sixth Embodiment In a sixth embodiment, an example will be described in which the configuration of the second embodiment is combined with the configuration of the third embodiment. Fig. 11 is a diagram showing an example of the hardware configuration of a power supply monitoring device 1F according to the sixth embodiment.

[0094] The power supply monitoring device 1F can be realized using a power supply circuit 91-1, control circuits 92B-1 and 92B-2, shutdown circuits 93-1, 93-2, and 93-3, power supply monitoring circuits 94-1, 94-2, and 94-3, mask circuits 95-1 and 95-2, peripheral circuits 96-1 and 96-2, and shutdown confirmation circuits 97-1 and 97-2. Each circuit has already been described, so a detailed description will be omitted here. The connections between the circuits are the same as those in the second and third embodiments.

[0095] Although the functional configuration is not shown in the figures, the functional configuration of power supply monitoring device 1F corresponds to the hardware configuration shown in Fig. 11, that is, in addition to the configuration of power supply monitoring device 1A shown in Fig. 1, it has shutdown confirmation units 15-1 and 15-2, and has control units 12B-1 and 12B-2 instead of the control units 12-1 and 12-2 of power supply monitoring device 1A. The connection relationships between the various functional units are the same as in the second and third embodiments.

[0096] Seventh Embodiment In a seventh embodiment, an example will be described in which the configuration of the second embodiment is combined with the configuration of the fourth embodiment. Fig. 12 is a diagram showing an example of the hardware configuration of a power supply monitoring device 1G according to the seventh embodiment.

[0097] The power supply monitoring device 1G can be realized using power supply circuits 91-1, 91-2, and 91-3, control circuits 92B-1 and 92B-2, shutdown circuits 93-1 and 93-2, power supply monitoring circuits 94-1, 94-2, 94-4, and 94-5, mask circuits 95-1 and 95-2, peripheral circuits 96-1 and 96-2, and shutdown confirmation circuits 97-1 and 97-2. Each circuit has already been described, so a detailed description will be omitted here. The connections between the circuits are the same as those in the second and fourth embodiments.

[0098] Although the functional configuration is not shown in the figures, the functional configuration of power supply monitoring device 1G corresponds to the hardware configuration shown in Fig. 12, that is, in addition to the configuration of power supply monitoring device 1A shown in Fig. 1, it has power supply units 11-2 and 11-3, shutdown confirmation units 15-1 and 15-2, and monitoring units 16-1 and 16-2, and has control units 12B-1 and 12B-2 instead of control units 12-1 and 12-2. The connection relationships between the various functional units are the same as in the second and fourth embodiments.

[0099] Eighth Embodiment In an eighth embodiment, an example will be described in which the configuration of the second embodiment is combined with the configuration of the fifth embodiment. Fig. 13 is a diagram showing an example of the hardware configuration of a power supply monitoring device 1H according to the eighth embodiment.

[0100] The power supply monitoring device 1H can be realized using power supply circuits 91-1 and 91-4, control circuits 92B-1 and 92B-2, shutdown circuits 93-1 and 93-2, power supply monitoring circuits 94-1, 94-2, 94-6, and 94-7, mask circuits 95-1 and 95-2, peripheral circuits 96-1 and 96-2, and shutdown confirmation circuits 97-1 and 97-2. Each circuit has already been described, so a detailed description will be omitted here. The connections between the circuits are the same as those in the second and fifth embodiments.

[0101] Although the functional configuration is not shown in the figures, the functional configuration of power supply monitoring device 1H corresponds to the hardware configuration shown in Fig. 13, that is, in addition to the configuration of power supply monitoring device 1A shown in Fig. 1, it has a power supply unit 11-4, shutdown confirmation units 15-1 and 15-2, and monitoring units 16-3 and 16-4, and has control units 12B-1 and 12B-2 instead of control units 12-1 and 12-2. The connection relationships between the various functional units are the same as in the second and fifth embodiments.

[0102] Ninth Embodiment In a ninth embodiment, an example will be described in which the configuration of the third embodiment is combined with the configuration of the fourth embodiment. Fig. 14 is a diagram showing an example of the hardware configuration of a power supply monitoring device 1I according to the ninth embodiment.

[0103] The power supply monitoring device 1I can be realized using power supply circuits 91-1, 91-2, and 91-3, control circuits 92-1 and 92-2, shutoff circuits 93-1, 93-2, and 93-3, power supply monitoring circuits 94-1, 94-2, 94-3, 94-4, and 94-5, mask circuits 95-1 and 95-2, and peripheral circuits 96-1 and 96-2. Each circuit has already been described, so a detailed description will be omitted here. The connections between the circuits are the same as those in the third and fourth embodiments.

[0104] Although the functional configuration is not shown in the figures, the functional configuration of power supply monitoring device 1I corresponds to the hardware configuration shown in Fig. 14, that is, in addition to the configuration of power supply monitoring device 1A shown in Fig. 1, it has power supply units 11-2 and 11-3, a switching unit 13-3, and monitoring units 16-1 and 16-2. The connection relationships between the functional units are the same as in the third and fourth embodiments.

[0105] Tenth Embodiment In a tenth embodiment, an example will be described in which the configuration of the third embodiment is combined with the configuration of the fifth embodiment. Fig. 15 is a diagram showing an example of the hardware configuration of a power supply monitoring device 1J according to the tenth embodiment.

[0106] The power supply monitoring device 1J can be realized using power supply circuits 91-1 and 91-4, control circuits 92-1 and 92-2, shutoff circuits 93-1, 93-2, and 93-3, power supply monitoring circuits 94-1, 94-2, 94-3, 94-6, and 94-7, mask circuits 95-1 and 95-2, and peripheral circuits 96-1 and 96-2. Each circuit has already been described, so a detailed description will be omitted here. The connections between the circuits are the same as those in the third and fifth embodiments.

[0107] Although the functional configuration is not shown in the figures, the functional configuration of power supply monitoring device 1J corresponds to the hardware configuration shown in Fig. 15, that is, in addition to the configuration of power supply monitoring device 1A shown in Fig. 1, it has a power supply unit 11-4, a switching unit 13-3, and monitoring units 16-3 and 16-4. The connection relationships between the functional units are the same as in the third and fifth embodiments.

[0108] Eleventh Embodiment In an eleventh embodiment, an example will be described in which the configurations of the second embodiment, the third embodiment, and the fourth embodiment are combined. Fig. 16 is a diagram illustrating an example of the hardware configuration of a power supply monitoring device 1K according to the eleventh embodiment.

[0109] The power supply monitoring device 1K can be realized using power supply circuits 91-1, 91-2, and 91-3, control circuits 92B-1 and 92B-2, shutdown circuits 93-1, 93-2, and 93-3, power supply monitoring circuits 94-1, 94-2, 94-3, 94-4, and 94-5, mask circuits 95-1 and 95-2, peripheral circuits 96-1 and 96-2, and shutdown confirmation circuits 97-1 and 97-2. Each circuit has already been described, so a detailed description will be omitted here. The connections between the circuits are the same as those in the second, third, and fourth embodiments.

[0110] Although the functional configuration is not shown in the figures, the functional configuration of power supply monitoring device 1K corresponds to the hardware configuration shown in Fig. 16, that is, in addition to the configuration of power supply monitoring device 1A shown in Fig. 1, it has power supply units 11-2 and 11-3, switching unit 13-3, shutdown confirmation units 15-1 and 15-2, and monitoring units 16-1 and 16-2, and has control units 12B-1 and 12B-2 instead of control units 12-1 and 12-2 of power supply monitoring device 1A. The connection relationships between the various functional units are the same as in the second, third and fourth embodiments.

[0111] Twelfth Embodiment In a twelfth embodiment, an example will be described in which the configurations of the second embodiment, the third embodiment, and the fifth embodiment are combined. Fig. 17 is a diagram illustrating an example of the hardware configuration of a power supply monitoring device 1L according to the twelfth embodiment.

[0112] The power supply monitoring device 1L can be realized using power supply circuits 91-1 and 91-4, control circuits 92B-1 and 92B-2, shutdown circuits 93-1, 93-2, and 93-3, power supply monitoring circuits 94-1, 94-2, 94-3, 94-6, and 94-7, mask circuits 95-1 and 95-2, peripheral circuits 96-1 and 96-2, and shutdown confirmation circuits 97-1 and 97-2. Each circuit has already been described, so a detailed description will be omitted here. The connections between the circuits are the same as those in the second, third, and fifth embodiments.

[0113] Although the functional configuration is not shown in the figures, the functional configuration of power supply monitoring device 1L is a configuration corresponding to the hardware configuration shown in Fig. 17, that is, in addition to the configuration of power supply monitoring device 1A shown in Fig. 1, it has a power supply unit 11-4, a switching unit 13-3, shutdown confirmation units 15-1 and 15-2, and monitoring units 16-3 and 16-4, and has control units 12B-1 and 12B-2 instead of the control units 12-1 and 12-2 of power supply monitoring device 1A. Furthermore, the connection relationships of the various functional units are the same as in the second, third and fifth embodiments.

[0114] As shown in the sixth to twelfth embodiments, when the second to fifth embodiments are combined, the effects of the combined embodiments are achieved.

[0115] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0116] 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L Power supply monitoring device, 11-1, 11-2, 11-3, 11-4 Power supply unit, 12-1, 12-2, 12B-1, 12B-2 Control unit, 13-1, 13-2, 13-3 Switching unit, 14-1, 14-2 Mask unit, 15-1, 15-2 Shutdown confirmation unit, 16-1, 16-2, 16-3, 16-4 Monitoring unit, 91-1, 91-2, 91-3, 91-4 Power supply circuit, 92-1, 92-2, 92B-1, 92B-2 Control circuit, 93-1, 93-2, 93-3 Shutdown circuit, 94-1, 94-2, 94-3, 94-4, 94-5, 94-6, 94-7 power supply monitoring circuit, 95-1, 95-2 mask circuit, 96-1, 96-2 peripheral circuit, 97-1, 97-2 shutdown confirmation circuit, 121-1, 121-2, 921-1, 921-2 shutdown request function, 122-1, 122-2, 922-1, 922-2 mask request function, 123-1, 123-2, 924-1, 924-2 shutdown judgment function, 923-1, 923-2 communication function.

Claims

1. A power supply monitoring device comprising: a first power supply unit that supplies power; a first control unit that operates on power supplied from the first power supply unit; a second control unit that operates on power supplied from the first power supply unit; a first switching unit that performs switching control to switch between a conductive state in which power is supplied from the first power supply unit to each of the first control unit and the second control unit and a cut-off state in which the supply of power is cut off, in response to switching requests output by the first control unit and the second control unit; a second switching unit that is connected in parallel with the first switching unit and performs switching control to switch between the conductive state and the cut-off state in response to switching requests output by the first control unit and the second control unit; a first masking unit that disables switching control by the first switching unit from the conductive state to the cut-off state in response to a first masking request output by the first control unit; and a second masking unit that disables switching control by the second switching unit from the conductive state to the cut-off state in response to a second masking request output by the second control unit.

2. The power supply monitoring device of claim 1, further comprising: a first interruption confirmation unit capable of transmitting first status information indicating whether the first switching unit is in the conductive state or the interrupted state; and a second interruption confirmation unit capable of transmitting second status information indicating whether the second switching unit is in the conductive state or the interrupted state, wherein the first control unit has a first interruption determination function that can receive the first status information and share the received first status information with the second control unit by communication, and the second control unit has a second interruption determination function that can receive the second status information and share the received second status information with the first control unit by communication.

3. The power supply monitoring device according to claim 1 or 2, further comprising: a third switching unit connected to the power supply path between the first power supply unit and the first switching unit and the second switching unit, and performing switching control to switch between a conductive state in which power is supplied from the first power supply unit to each of the first control unit and the second control unit, and a cut-off state in which power is cut off.

4. A second power supply unit connected to a power supply path between the first power supply unit and the first control unit, and controlling the power supplied by the first power supply unit to supply power to the first control unit; a third power supply unit connected to a power supply path between the first power supply unit and the second control unit, and controlling the power supplied by the first power supply unit to supply power to the second control unit; a first monitoring unit that monitors a first voltage that is a voltage on the power supply path between the second power supply unit and the first control unit, and is capable of outputting the switching request to the first switching unit and the second switching unit based on the first voltage, and is also capable of relaying the switching request output by the second control unit and outputting it to the first switching unit and the second switching unit; 4. The power supply monitoring device according to claim 1, further comprising: a second monitoring unit that is capable of monitoring a second voltage that is a voltage of a power supply path between the third power supply unit and the second control unit, and outputting the switching request to the first switching unit and the second switching unit based on the second voltage, and that is capable of relaying the switching request output by the first control unit and outputting it to the first switching unit and the second switching unit.

5. The power supply monitoring device according to any one of claims 1 to 3, further comprising: a fourth power supply unit connected between the first power supply unit and the first control unit and the second control unit, and controlling the power supplied by the first power supply unit to supply power to the first control unit and the second control unit; a third monitoring unit capable of monitoring a third voltage which is a voltage of a power supply path between the fourth power supply unit and the first control unit and the second control unit, and outputting the switching request to the first switching unit and the second switching unit based on the third voltage, and relaying the switching request output by the second control unit to output it to the first switching unit and the second switching unit; and a fourth monitoring unit capable of monitoring the third voltage, outputting the switching request to the first switching unit and the second switching unit based on the third voltage, and relaying the switching request output by the first control unit to output it to the first switching unit and the second switching unit.

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