Power supply control device, power supply control method, and computer program

Abstract

To provide a power supply control device in which a component can be easily changed according to a load, and a power supply control method and a computer program for controlling power supply to the power supply control device.SOLUTION: A vehicular power supply control device 10 controls power supply to a first load E. A first controller G is formed on a first substrate, and controls power supply to the first load E. A second controller H is formed on a second substrate that is different from the first substrate, and gives an instruction to perform a power supply-related operation to the first controller G. Each of the first controller G and the second controller H has a first switch 20 and a circuit switch 30. The first switch 20 and the circuit switch 30 are disposed on a current path of a current flowing via the first load E. The second controller H gives an instruction to turn on / off the first switch 20.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a power supply control device, a power supply control method, and a computer program. [Background technology]

[0002] A vehicle is equipped with a power supply control device (for example, Patent Document 1) that controls power supply from a DC power supply to a load. In the power supply control device described in Patent Document 1, a switch is disposed in a current path of a current flowing from the DC power supply to the load. The switch is connected to a switching circuit. The switching circuit switches the switch on or off according to an input signal. This controls the power supply from the DC power supply to the load. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-154647 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, a power supply control device is realized by a switch, a switching circuit, and an output device that outputs an input signal. It is preferable that the components of the power supply control device can be easily changed according to the load. For example, if the switch and the switching circuit can be changed without changing the output device, a power supply control device that can handle various loads can be easily realized.

[0005] The present disclosure has been made in consideration of the above circumstances, and its purpose is to provide a power supply control device that allows components to be easily changed depending on the load, and a power supply control method and computer program that can realize the power supply control of this power supply control device. [Means for solving the problem]

[0006] A power supply control device according to one embodiment of the present disclosure is a power supply control device for a vehicle that controls power supply to a load, and includes a controller formed on a first substrate and controlling the power supply to the load, and an indicator formed on a second substrate different from the first substrate and instructing the controller on operations related to the power supply, wherein the controller has a load switch arranged in a current path of a current flowing through the load, and the indicator has a circuit switch arranged in the current path and a processing unit that executes processing, and the processing unit instructs the load switch to be switched on or off.

[0007] A power supply control method according to one embodiment of the present disclosure is a power supply control method for a vehicle power supply control device including a controller formed on a first substrate and controlling power supply to a load, and an indicator formed on a second substrate different from the first substrate and instructing the controller on an operation related to the power supply, the controller having a load switch arranged in a current path of a current flowing through the load, and the indicator having a circuit switch arranged in the current path, the method including the steps of: instructing to switch the load switch off while the circuit switch is on; acquiring a current value of the current flowing through the current path after instructing to switch the load switch off; determining whether the acquired current value exceeds a current threshold; and instructing to switch the circuit switch off if it is determined that the current value exceeds the current threshold, wherein a computer executes the steps of:

[0008] A computer program according to one embodiment of the present disclosure includes a controller formed on a first substrate and controlling power supply to a load, and an indicator formed on a second substrate different from the first substrate and instructing the controller on operations related to the power supply, wherein the controller has a load switch arranged in a current path of a current flowing through the load, and the indicator has a circuit switch arranged in the current path. The computer program causes a computer to control power supply in a power supply control device for a vehicle, the computer program including: instructing the computer to switch off the load switch while the circuit switch is on; acquiring a current value of the current flowing through the current path after instructing the computer to switch off the load switch; determining whether the acquired current value exceeds a current threshold; and instructing the computer to switch off the circuit switch if it is determined that the current value exceeds the current threshold.

[0009] The present disclosure can be realized not only as a power supply control device having such a characteristic processing unit, but also as a power supply control method having such characteristic processing steps, or as a computer program for causing a computer to execute such steps. Furthermore, the present disclosure can be realized as a semiconductor integrated circuit that realizes part or all of the power supply control device, or as a power supply control system including the power supply control device. Effect of the Invention

[0010] According to the power supply control device according to the above aspect, the components can be easily changed according to the load. According to the power supply control method and computer program of the above aspects, it is possible to realize the power supply control of the power supply control device described above. [Brief description of the drawings]

[0011] [Figure 1] 1 is a block diagram showing a configuration of a main part of a power supply system according to a first embodiment. [Diagram 2]FIG. 2 is a block diagram showing a configuration of a main part of a first controller. [Diagram 3] FIG. 2 is a plan view of the first controller. [Figure 4] FIG. 4 is a block diagram showing a configuration of a main part of a second controller. [Diagram 5] FIG. 4 is a plan view of the second controller. [Figure 6] FIG. 2 is a block diagram showing a main configuration of a microcomputer; [Figure 7] 13 is a flowchart showing a procedure for a switch control process. [Figure 8] 6 is a flowchart showing a procedure of a first power supply control process. [Figure 9] 6 is a flowchart showing a procedure of a first power supply control process. [Figure 10] 4 is a timing chart showing a first example of the operation of the power supply control device. [Figure 11] 10 is a timing chart showing a second example of the operation of the power supply control device. [Figure 12] 10 is a flowchart showing the procedure of a switch control process in the second embodiment. [Figure 13] 6 is a flowchart showing a procedure of a first power supply control process. [Figure 14] 4 is a timing chart showing an example of the operation of the power supply control device. [Figure 15] 13 is a flowchart showing the procedure of a first power supply control process in the third embodiment. [Figure 16] 13 is a flowchart showing the procedure of a first power supply control process in the third embodiment. [Figure 17] 4 is a timing chart showing a first example of the operation of the power supply control device. [Figure 18] 10 is a timing chart showing a second example of the operation of the power supply control device. [Figure 19] 13 is a flowchart showing the procedure of a first power supply control process in the fourth embodiment. [Figure 20] 4 is a timing chart showing an example of the operation of the power supply control device. [Figure 21]FIG. 13 is a block diagram showing a configuration of a main part of a power supply system according to a fifth embodiment. [Figure 22] FIG. 2 is a block diagram showing a main configuration of a microcomputer; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] [Description of the embodiments of the present disclosure] First, the embodiments of the present disclosure will be listed and described. At least a part of the embodiments described below may be arbitrarily combined.

[0013] (1) A power supply control device according to one embodiment of the present disclosure is a power supply control device for a vehicle that controls power supply to a load, and includes: a controller formed on a first substrate and controlling power supply to the load; and an indicator formed on a second substrate different from the first substrate and instructing the controller on an operation related to the power supply, wherein the controller has a load switch arranged in a current path of a current flowing through the load, and the indicator has a circuit switch arranged in the current path and a processing unit that performs processing, and the processing unit instructs the load switch to be switched on or off.

[0014] (2) In a power supply control device according to one aspect of the present disclosure, the processing unit of the indicator instructs the load switch to be switched off while the circuit switch is on, and after instructing the load switch to be switched off, acquires a current value of the current flowing through the current path, determines whether the acquired current value exceeds a current threshold, and if it is determined that the current value exceeds the current threshold, instructs the circuit switch to be switched off.

[0015] (3) In a power supply control device according to one embodiment of the present disclosure, the processing unit of the indicator determines whether an ignition switch of the vehicle has been switched off, and when it determines that the current value exceeds the current threshold, when it determines that the ignition switch of the vehicle has been switched off, instructs the circuit switch to be switched off.

[0016] (4) In a power supply control device according to one embodiment of the present disclosure, the number of each of the loads and the load switches is two or more, a plurality of load switches are arranged in each current path of a plurality of currents flowing through the plurality of loads, and the current flowing through the circuit switch is divided into the plurality of currents.

[0017] (5) In a power supply control device according to one embodiment of the present disclosure, the controller has a switching circuit that switches the load switch on or off, current flows through the circuit switch and the load switch in that order, and power is supplied to the switching circuit via the circuit switch, and the processing unit of the indicator instructs the circuit switch to be switched off when an ignition switch of the vehicle is switched off.

[0018] (6) A power supply control method according to one aspect of the present disclosure includes a controller formed on a first substrate and controlling power supply to a load, and an indicator formed on a second substrate different from the first substrate and instructing the controller on an operation related to the power supply, wherein the controller has a load switch arranged in a current path of a current flowing through the load, and the indicator has a circuit switch arranged in the current path, wherein a computer executes the following steps: instructing to switch the load switch off while the circuit switch is on; acquiring a current value of the current flowing through the current path after instructing to switch the load switch off; determining whether the acquired current value exceeds a current threshold; and instructing to switch the circuit switch off if it is determined that the current value exceeds the current threshold.

[0019] (7) A computer program according to one embodiment of the present disclosure includes a controller formed on a first substrate and controlling power supply to a load, and an indicator formed on a second substrate different from the first substrate and instructing the controller on an operation related to the power supply, the controller having a load switch arranged in a current path of a current flowing through the load, and the indicator having a circuit switch arranged in the current path. The computer program causes a computer to control power supply in a power supply control device for a vehicle, the computer program including: instructing the computer to switch off the load switch while the circuit switch is on; acquiring a current value of the current flowing through the current path after instructing the computer to switch off the load switch; determining whether the acquired current value exceeds a current threshold; and instructing the computer to switch off the circuit switch if it is determined that the current value exceeds the current threshold.

[0020] In the power supply control device according to the above embodiment, the controller and the indicator are formed on the first and second substrates, respectively. Therefore, the controller including the load switch can be easily changed according to the load. By combining various controllers with a common indicator, a configuration corresponding to the load whose operation is controlled can be realized. In addition, when the load switch of the controller is fixed to ON, the power supply to the load can be stopped by switching the circuit switch of the indicator to OFF.

[0021] In the power supply control device, the power supply control method, and the computer program according to the above aspect, when the circuit switch is on, an instruction is given to switch off the load switch of the controller. If the current value of the current flowing through the load switch exceeds a current threshold despite the instruction to switch off the load switch, the instruction switches off the circuit switch of the controller. This makes it possible to stop the power supply to the load. The current threshold is, for example, zero A or a positive current value close to zero A.

[0022] In the power supply control device according to the above aspect, the loads included in the vehicle include an electric device that is required to continue operating if re-operation is not possible. The load is, for example, a headlight. When the load is such an electric device, even if an instruction to switch off the load switch is received, if the current value exceeds the current threshold, the circuit switch is maintained on until the ignition switch is switched off.

[0023] In the power supply control device according to the above aspect, the circuit switch is disposed upstream of the plurality of load switches, so that the power supply to the plurality of loads can be stopped by switching off the circuit switch.

[0024] In the power supply control device according to the above aspect, the power supply to the switching circuit can be stopped by switching the circuit switch off. When the ignition switch is switched off, the circuit switch is switched off. This allows the power to be consumed efficiently in the switching circuit.

[0025] [Details of the embodiment of the present disclosure] Specific examples of power supply systems according to embodiments of the present disclosure will be described below with reference to the drawings. Note that the present invention is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

[0026] (Embodiment 1) <Power supply system configuration> FIG. 1 is a block diagram showing a configuration of a main part of a power supply system 1 in a first embodiment. The power supply system 1 is mounted on a vehicle C. The power supply system 1 includes a power supply control device 10, a DC power supply 11, a first load E, and a second load F. The DC power supply 11 is, for example, a battery. The power supply control device 10 is connected to a positive electrode of the DC power supply 11, one end of the first load E, and one end of the second load F, respectively. The negative electrode of the DC power supply 11, the other end of the first load E, and the other end of the second load F are grounded. The grounding is achieved, for example, by connection to the body of the vehicle C.

[0027] A DC power supply 11 supplies power to a first load E and a second load F via a power supply control device 10. The first load E and the second load F are each an electrical device. When power is supplied to the first load E, the first load E operates. When power supply to the first load E is stopped, the first load E stops operating. Similarly, when power is supplied to the second load F, the second load F operates. When power supply to the second load F is stopped, the second load F stops operating. The power supply control device 10 controls the power supply to the first load E and the second load F separately.

[0028] <Configuration of power supply control device 10> The power supply control device 10 has a first controller G and a second controller H. The first controller G has a first switch 20. The second controller H has a circuit switch 30 and a second switch 31. The first switch 20, the circuit switch 30, and the second switch 31 are each an N-channel type field effect transistor (FET). The source of the first switch 20 is connected to one end of a first load E. The drain of the first switch 20 is connected to the source of the circuit switch 30. The drain of the circuit switch 30 is connected to the positive electrode of the DC power supply 11. The source of the second switch 31 is connected to one end of a second load F. The drain of the second switch 31 is connected to the positive electrode of the DC power supply 11.

[0029] When the first switch 20, the circuit switch 30, and the second switch 31 are in the on state, the resistance between the drain and the source is sufficiently small. Therefore, a current can flow through the drain and the source. When the first switch 20, the circuit switch 30, and the second switch 31 are in the off state, the resistance is sufficiently large. Therefore, no current flows through the drain and the source.

[0030] An ignition signal indicating the state of the ignition switch of the vehicle C is input to the second controller H. When the ignition switch of the vehicle C is on, the ignition signal indicates that the ignition switch is on. When the ignition switch of the vehicle C is off, the ignition signal indicates that the ignition switch is off.

[0031] The second controller H switches the circuit switch 30 on when the ignition switch of the vehicle C is switched on. The second controller H switches the circuit switch 30 off when the ignition switch is switched off. The first controller G switches the first switch 20 on or off while the circuit switch 30 is on.

[0032] When both the first switch 20 and the circuit switch 30 are on, a current flows from the positive electrode of the DC power supply 11 through the circuit switch 30, the first switch 20, and the first load E in that order. This causes power to be supplied to the first load E. As described above, the circuit switch 30 and the first switch 20 are disposed in the current path of the current flowing through the first load E. The first switch 20 functions as a load switch. When at least one of the first switch 20 and the circuit switch 30 is off, no current flows through the first load E. At this time, power supply to the first load E is stopped.

[0033] The second controller H instructs the first controller G on an operation related to power supply to the first load E while the circuit switch 30 is on. The second controller H instructs the first controller G to turn the first switch 20 on or off as an operation related to power supply to the first load E. The first controller G switches the first switch 20 on or off according to the instruction of the second controller H. This controls the power supply to the first load E. The second controller H functions as an indicator.

[0034] The second controller H switches the second switch 31 on or off. When the second switch 31 is switched from off to on, a current flows from the positive electrode of the DC power supply 11 to the second switch 31 and the second load F in that order. This causes power to be supplied to the second load F. When the second switch 31 is switched from on to off, power supply to the second load F is stopped. In this way, the second controller H controls the power supply to the second load F by switching the second switch 31 on or off.

[0035] Hereinafter, the current value of the current flowing through the first switch 20 and the first load E will be referred to as the load current value. Analog current value information indicating the load current value is input to the second controller H. In addition, an activation signal and a stop signal are input to the second controller H. The activation signal indicates which of the first load E and the second load F is to be activated. The stop signal indicates which of the first load E and the second load F is to be stopped.

[0036] When an actuation signal indicating the first load E is input, the second controller H instructs the first controller G to turn on the first switch 20. When the load current value is equal to or less than the current threshold value despite the instruction to turn on the first switch 20, the second controller H notifies the occurrence of an off fault. Specifically, the second controller H performs the notification by outputting a notification signal indicating the occurrence of an off fault. The current threshold value is a constant value that is set in advance. The current threshold value is zero A or a positive current value close to zero A. The off fault is a phenomenon in which the load current value is equal to or less than the current threshold value despite the instruction to turn on the first switch 20.

[0037] When a stop signal indicating the first load E is input, the second controller H instructs the first controller G to turn off the first switch 20. When the load current value exceeds the current threshold value despite the instruction to turn off the first switch 20, the second controller H notifies the occurrence of an on-fault. Specifically, the second controller H performs the notification by outputting a notification signal indicating the occurrence of an on-fault. The on-fault is a phenomenon in which the load current value exceeds the current threshold value despite the instruction to turn off the first switch 20.

[0038] When an ON failure occurs in the first switch 20, the second controller H switches the circuit switch 30 off. This stops the power supply to the first load E. The first load E is an electric device that does not interfere with the operation of the vehicle C even when it is constantly stopped. The first load E is, for example, a music player.

[0039] The second controller H switches the second switch 31 ON when the actuation signal indicates a second load F. The second controller H switches the second switch 31 OFF when the stop signal indicates a second load F.

[0040] <Configuration of the first controller G> 2 is a block diagram showing the configuration of the main parts of the first controller G. In addition to the first switch 20, the first controller G has a first drive circuit 21, a current output section 22, and a resistor 23.

[0041] As described above, the drain and source of the first switch 20 are connected to the source of the circuit switch 30 and one end of the first load E, respectively. The drain and gate of the first switch 20 are each connected to the first drive circuit 21. The first drive circuit 21 is further connected to the second controller H. The first drive circuit 21 is grounded.

[0042] The drain of the first switch 20 is connected to the current output section 22. The current output section 22 is further connected to one end of a resistor 23. The other end of the resistor 23 is grounded. The connection node between the current output section 22 and the resistor 23 is connected to a second controller H.

[0043] When the circuit switch 30 is switched on, a current flows from the positive electrode of the DC power supply 11 to the circuit switch 30 and the first drive circuit 21 in this order. As a result, power is supplied to the first drive circuit 21 via the circuit switch 30. When the circuit switch 30 is switched off, power supply to the first drive circuit 21 is stopped. While power is being supplied to the first drive circuit 21, the first drive circuit 21 operates. When power supply to the first drive circuit 21 is stopped, the first drive circuit 21 stops operating.

[0044] In the first switch 20, when the gate voltage value, whose reference potential is the source potential, is equal to or greater than a certain voltage value, the first switch 20 is on. In the first switch 20, when the gate voltage value, whose reference potential is the source potential, is less than a certain voltage value, the first switch 20 is off.

[0045] The second controller H outputs a high-level voltage and a low-level voltage to the first drive circuit 21. When the voltage output to the first drive circuit 21 is switched from a low-level voltage to a high-level voltage while power is being supplied to the first drive circuit 21, the first drive circuit 21 increases the gate voltage value, the reference potential of which is the ground potential, in the first switch 20. As a result, the gate voltage value, the reference potential of which is the source potential, increases to a voltage value equal to or higher than a certain voltage value in the first switch 20. As a result, the first switch 20 is switched on.

[0046] In a similar case, when the voltage output to the first drive circuit 21 switches from a high-level voltage to a low-level voltage, the first drive circuit 21 reduces the gate voltage value, the reference potential of which is the ground potential, in the first switch 20. As a result, the gate voltage value, the reference potential of which is the source potential, in the first switch 20, drops to a voltage value less than a certain voltage value. As a result, the first switch 20 is switched off.

[0047] As described above, the first drive circuit 21 switches the first switch 20 on or off by adjusting the voltage value of the gate, whose reference potential is the potential of the source. The first drive circuit 21 functions as a switching circuit. The second controller H outputs a high-level voltage to the first drive circuit 21 to instruct the first switch 20 to be switched on. The second controller H outputs a low-level voltage to the first drive circuit 21 to instruct the first switch 20 to be switched off.

[0048] As described above, when power is not supplied to the first drive circuit 21, the first drive circuit 21 stops operating. When the first drive circuit 21 stops operating, in the first switch 20, the gate voltage value, the reference potential of which is the source potential, is less than a certain voltage value. Therefore, the first switch 20 is off.

[0049] The current output unit 22 draws in a current from the drain of the first switch 20 and outputs the drawn current to the resistor 23. The current value of the current drawn by the current output unit 22 is expressed as (load current value) / (predetermined number). As described above, the load current value is the current value of the current flowing through the first switch 20 and the first load E. The predetermined number is a constant value, for example, 1000. The voltage value between both ends of the resistor 23 is output to the second controller H as analog current value information. The current value information is expressed as (load current value)·(resistance value of resistor 23) / (predetermined number). "·" represents a product. Since the resistance value of resistor 23 and the predetermined number are constant values, the current value information indicates the load current value.

[0050] <Exterior of the first controller G> Fig. 3 is a plan view of the first controller G. The first controller G is formed on a first substrate B1. As shown in Fig. 3, a first switch 20, a first drive circuit 21, a current output unit 22, and a resistor 23 are arranged on the first substrate B1. Specifically, one or more elements constituting the first switch 20, the first drive circuit 21, the current output unit 22, and the resistor 23 are arranged on the first substrate B1.

[0051] <Configuration of the second controller H> 4 is a block diagram showing the configuration of the main parts of the second controller H. In addition to a circuit switch 30 and a second switch 31, the second controller H has a switch drive circuit 32, a second drive circuit 33, a microcomputer (hereinafter referred to as a microcomputer) 34, and a second regulator 35.

[0052] As described above, the drains of the circuit switch 30 and the second switch 31 are connected to the positive electrode of the DC power supply 11. The source of the circuit switch 30 is connected to the drain of the first switch 20 of the first controller G. The source of the second switch 31 is connected to one end of the second load F.

[0053] The gates of the circuit switch 30 and the second switch 31 are connected to the switch drive circuit 32 and the second drive circuit 33, respectively. The switch drive circuit 32 and the second drive circuit 33 are connected to the microcomputer 34. The switch drive circuit 32, the second drive circuit 33, and the microcomputer 34 are each grounded. The drains of the circuit switch 30 and the second switch 31 are connected to the switch drive circuit 32, the second drive circuit 33, and the second regulator 35. The second regulator 35 is further connected to the microcomputer 34.

[0054] The voltage across the DC power supply 11 is input to the second regulator 35. The second regulator 35 steps down the voltage across the DC power supply 11 to a constant voltage and outputs the stepped-down voltage to the microcomputer 34. As a result, a current flows from the positive electrode of the DC power supply 11 to the second regulator 35 and then to the microcomputer 34. As a result, power is supplied to the microcomputer 34. A current flows from the positive electrode of the DC power supply 11 to the switch drive circuit 32 and the second drive circuit 33. As a result, power is supplied to the switch drive circuit 32 and the second drive circuit 33.

[0055] In the circuit switch 30, when the voltage value of the gate, whose reference potential is the potential of the source, is equal to or greater than a certain voltage value, the circuit switch 30 is on. In the circuit switch 30, when the voltage value of the gate, whose reference potential is the potential of the source, is less than a certain voltage value, the circuit switch 30 is off. The microcomputer 34 outputs a high level voltage and a low level voltage to the switch drive circuit 32.

[0056] When the voltage output to the switch drive circuit 32 switches from a low-level voltage to a high-level voltage, the switch drive circuit 32 increases the gate voltage value, whose reference potential is the ground potential, in the circuit switch 30. As a result, the gate voltage value, whose reference potential is the source potential, in the circuit switch 30 increases to a voltage equal to or higher than a certain voltage value. As a result, the circuit switch 30 switches on.

[0057] When the voltage output to the switch drive circuit 32 switches from a high-level voltage to a low-level voltage, the switch drive circuit 32 reduces the gate voltage value, whose reference potential is the ground potential, in the circuit switch 30. As a result, the gate voltage value, whose reference potential is the source potential, in the circuit switch 30 drops to a voltage less than a certain voltage value. As a result, the circuit switch 30 switches off.

[0058] As described above, the switch drive circuit 32 switches the circuit switch 30 on or off by adjusting the voltage value of the gate, whose reference potential is the potential of the source. The microcomputer 34 instructs the switch drive circuit 32 to switch the circuit switch 30 on by outputting a high-level voltage to the switch drive circuit 32. The microcomputer 34 instructs the switch drive circuit 32 to switch the circuit switch 30 off by outputting a low-level voltage to the switch drive circuit 32.

[0059] In the second switch 31, when the gate voltage value, whose reference potential is the source potential, is equal to or greater than a certain voltage value, the second switch 31 is on. In the second switch 31, when the gate voltage value, whose reference potential is the source potential, is less than a certain voltage value, the second switch 31 is off. The microcomputer 34 outputs a high level voltage and a low level voltage to the second drive circuit 33.

[0060] The second drive circuit 33 switches the second switch 31 on or off in response to the voltage output to the second drive circuit 33. This switching is similar to the switching of the circuit switch 30 performed by the switch drive circuit 32 in response to the voltage output to the switch drive circuit 32. In the explanation of the switching of the circuit switch 30, the switching of the second switch 31 can be explained by replacing the circuit switch 30 and the switch drive circuit 32 with the second switch 31 and the second drive circuit 33, respectively.

[0061] Therefore, the second drive circuit 33 switches the second switch 31 on or off by adjusting the voltage value of the gate, whose reference potential is the potential of the source. The microcomputer 34 instructs the second switch 31 to be switched on by outputting a high-level voltage to the second drive circuit 33. The microcomputer 34 instructs the second switch 31 to be switched off by outputting a low-level voltage to the second drive circuit 33.

[0062] The microcomputer 34 outputs a high-level voltage or a low-level voltage to the first drive circuit 21. The microcomputer 34 outputs a high-level voltage to the first drive circuit 21 to instruct the first switch 20 to be switched on. The microcomputer 34 outputs a low-level voltage to the first drive circuit 21 to instruct the first switch 20 to be switched off. Analog current value information is input from the second controller H to the microcomputer 34.

[0063] An ignition signal is input to the microcomputer 34. When the ignition switch of the vehicle C is switched on, the microcomputer 34 outputs a high-level voltage to the switch drive circuit 32 to instruct the circuit switch 30 to be switched on. When the ignition switch of the vehicle C is switched off, the microcomputer 34 outputs a low-level voltage to the switch drive circuit 32 to instruct the circuit switch 30 to be switched off.

[0064] The microcomputer 34 instructs the first switch 20 to be switched on or off while the circuit switch 30 is on. When an actuation signal indicating the first load E is input, the microcomputer 34 instructs the first switch 20 to be switched on by switching the voltage output to the first drive circuit 21 of the first controller G to a high-level voltage. When a stop signal indicating the first load E is input, the microcomputer 34 instructs the first switch 20 to be switched off by switching the voltage output to the first drive circuit 21 to a low-level voltage.

[0065] Although the microcomputer 34 has instructed the first switch 20 to be turned on, Load current value is equal to or less than the current threshold, the microcomputer 34 notifies the occurrence of an OFF fault. Specifically, the microcomputer 34 notifies the occurrence of an OFF fault by outputting a notification signal indicating the occurrence of an OFF fault. The microcomputer 34 notifies the occurrence of an ON fault when the load current value exceeds the current threshold despite an instruction to switch the first switch 20 off. Specifically, the microcomputer 34 notifies the occurrence of an ON fault by outputting a notification signal indicating the occurrence of an ON fault.

[0066] As described above, when the voltage output to the first drive circuit 21 is switched to a high-level voltage, the first drive circuit 21 switches the first switch 20 on. When the voltage output to the first drive circuit 21 is switched to a low-level voltage, the first drive circuit 21 switches the first switch 20 off. The high-level voltage is higher than the low-level voltage. For example, when the connection line connecting the first drive circuit 21 and the microcomputer 34 is grounded, the voltage output to the first drive circuit 21 is fixed to a low-level voltage. As a result, an OFF failure occurs. For example, when the connection line connecting the first drive circuit 21 and the microcomputer 34 is conductive with the connection line connecting the first switch 20 and the circuit switch 30 while the circuit switch 30 is on, the voltage output to the first drive circuit 21 is fixed to a high-level voltage. As a result, an ON failure occurs.

[0067] When the actuation signal indicates the second load F, the microcomputer 34 outputs a high-level voltage to the second drive circuit 33 to instruct the second switch 31 to be switched on. When the stop signal indicates the second load F, the microcomputer 34 outputs a low-level voltage to the second drive circuit 33 to instruct the second switch 31 to be switched off.

[0068] <External appearance of the second controller H> Fig. 5 is a plan view of the second controller H. The second controller H is formed on a second substrate B2 different from the first substrate B1. As shown in Fig. 5, a circuit switch 30, a second switch 31, a switch drive circuit 32, a second drive circuit 33, a microcomputer 34, and a second regulator 35 are arranged on the second substrate B2. Specifically, one or more elements constituting the circuit switch 30, the second switch 31, the switch drive circuit 32, the second drive circuit 33, the microcomputer 34, and the second regulator 35 are arranged on the second substrate B2.

[0069] <Configuration of Microcomputer 34> 6 is a block diagram showing the main configuration of the microcomputer 34. The microcomputer 34 has a voltage output unit 40, a first output unit T, a second output unit 41, an A / D conversion unit U, a signal input unit 42, a notification unit 43, a storage unit 44, and a control unit 45. These are connected to an internal bus 46. The voltage output unit 40, the first output unit T, and the second output unit 41 are further connected to the switch drive circuit 32, the first drive circuit 21, and the second drive circuit 33, respectively. The A / D conversion unit U is further connected to a connection node between the current output unit 22 and the resistor 23 of the first controller G.

[0070] The voltage output unit 40 outputs a high-level voltage or a low-level voltage to the switch drive circuit 32 in accordance with an instruction from the control unit 45. The control unit 45 instructs the switch drive circuit 32 to switch the circuit switch 30 on by having the voltage output unit 40 output a high-level voltage. The control unit 45 instructs the switch drive circuit 32 to switch the circuit switch 30 off by having the voltage output unit 40 output a low-level voltage.

[0071] The first output unit T outputs a high-level voltage or a low-level voltage to the first drive circuit 21 in accordance with an instruction from the control unit 45. The control unit 45 instructs the first drive circuit 21 to switch the first switch 20 on by making the first output unit T output a low-level voltage. The control unit 45 instructs the first drive circuit 21 to switch the first switch 20 off by making the first output unit T output a low-level voltage.

[0072] The second output unit 41 outputs a high-level voltage or a low-level voltage to the second drive circuit 33 in accordance with an instruction from the control unit 45. The control unit 45 instructs the second drive circuit 33 to switch the second switch 31 on by making the second drive circuit 33 output a high-level voltage. The control unit 45 instructs the second drive circuit 33 to switch the second switch 31 off by making the second output unit 41 output a low-level voltage.

[0073] Analog current value information is input to the A / D conversion unit U from the connection node of the first controller G. The A / D conversion unit U converts the input analog current value information into digital current value information. The control unit 45 acquires the digital current value information from the A / D conversion unit U.

[0074] The ignition signal, the activation signal and the stop signal are input to the signal input unit 42. The notification unit 43 issues a notification in accordance with an instruction from the control unit 45. The notification unit 43 realizes the notification by outputting a notification signal indicating the occurrence of an OFF failure or an ON failure.

[0075] The memory unit 44 is a non-volatile memory. A computer program P is stored in the memory unit 44. The control unit 45 has a processing element that executes processing, for example, a CPU (Central Processing Unit). The control unit 45 functions as a processing unit. The processing element (computer) of the control unit 45 executes a switch control process, a first power supply control process, a second power supply control process, and the like in parallel by executing the computer program P. The switch control process is a process of switching the circuit switch 30 on or off. The first power supply control process is a process of controlling power supply to the first load E. The second power supply control process is a process of controlling power supply to the second load F.

[0076] The computer program P may be stored in a non-transitory storage medium A so that the processing element of the control unit 45 can read it. In this case, the computer program P read from the storage medium A by a reading device (not shown) is written to the storage unit 44. The storage medium A is an optical disk, a flexible disk, a magnetic disk, a magneto-optical disk, a semiconductor memory, or the like. The optical disk is a CD (Compact Disc)-ROM (Read Only Memory), a DVD (Digital Versatile Disc)-ROM, or a BD (Blu-ray (registered trademark) Disc), or the like. The magnetic disk is, for example, a hard disk. The computer program P may also be downloaded from an external device (not shown) connected to a communication network (not shown), and the downloaded computer program P may be written to the storage unit 44.

[0077] The number of processing elements included in the control unit 45 is not limited to 1, and may be 2 or more. When the number of processing elements included in the control unit 45 is 2 or more, the multiple processing elements may cooperate to execute the switch control process, the first power supply control process, the second power supply control process, and the like.

[0078] The memory unit 44 stores a fault flag value. The fault flag value is either zero or one, and is changed by the control unit 45. A fault flag value of zero means that neither an on-fault nor an off-fault has occurred. A fault flag value of 1 means that at least one of an off-fault and an on-fault has occurred.

[0079] <Switch control processing> 7 is a flowchart showing the procedure of the switch control process. The switch control process is executed in a state where the circuit switch 30 is off. In the switch control process, the control unit 45 first determines whether or not the value of the failure flag is zero (step S1). If the control unit 45 determines that the value of the failure flag is zero (S1: YES), the control unit 45 determines whether or not the ignition switch of the vehicle C has been switched on based on the ignition signal input to the signal input unit 42 (step S2). If the control unit 45 determines that the ignition switch has not been switched on (S2: NO), the control unit 45 executes step S2 again and waits until the ignition switch is switched on.

[0080] When the control unit 45 determines that the ignition switch has been switched on (S2: YES), it instructs the switch driving circuit 32 to switch on the circuit switch 30 by causing the voltage output unit 40 to output a high-level voltage (step S3). The switch driving circuit 32 switches the circuit switch 30 on. Next, the control unit 45 determines whether or not the ignition switch of the vehicle C has been switched off based on the ignition signal input to the signal input unit 42 (step S4). When the control unit 45 determines that the ignition switch has not been switched off (S4: NO), it determines whether or not the value of the failure flag has been changed to 1 (step S5). The value of the failure flag is changed in the first power supply control process.

[0081] When the control unit 45 determines that the value of the failure flag has not been changed to 1 (S5: NO), it executes step S4 again and waits until the ignition switch is switched off or the value of the failure flag is changed to 1. When the control unit 45 determines that the ignition switch has been switched off (S4: YES) or the value of the failure flag has been changed to 1 (S5: YES), it instructs the switch driving circuit 32 to switch the circuit switch 30 off by making the voltage output unit 40 output a low-level voltage (step S6). As a result, the switch driving circuit 32 switches the circuit switch 30 off.

[0082] When the control unit 45 determines that the value of the failure flag is not zero (S1: NO), or after executing step S6, the control unit 45 ends the switch control process. After ending the switch control process, the control unit 45 executes the switch control process again.

[0083] As described above, when the value of the fault flag is 1, the circuit switch 30 is maintained off. When the value of the fault flag is zero and the ignition switch is turned on, the circuit switch 30 is turned on. After the circuit switch 30 is turned on, if the ignition switch is turned off or the value of the fault flag is changed to 1, the circuit switch 30 is turned off.

[0084] <First power supply control process> 8 and 9 are flowcharts showing the procedure of the first power supply control process. The first power supply control process is executed in a state where the first switch 20 is off. In the first power supply control process, the control unit 45 first determines whether or not the value of the failure flag is zero (step S11). When the control unit 45 determines that the value of the failure flag is not zero (S11: NO), the control unit 45 ends the first power supply control process. When the control unit 45 determines that the value of the failure flag is zero (S11: YES), the control unit 45 determines whether or not to operate the first load E (step S12). In step S12, when an operation signal indicating the first load E is input to the signal input unit 42, the control unit 45 determines that the first load E is to be operated. When an operation signal indicating the first load E is not input to the signal input unit 42, the control unit 45 determines that the first load E is not to be operated.

[0085] When the control unit 45 determines not to operate the first load E (S12: NO), it executes step S12 again and waits until an operation signal indicating the first load E is input to the signal input unit 42. When the control unit 45 determines to operate the first load E (S12: YES), it instructs the first drive circuit 21 to switch the first switch 20 on by outputting a high-level voltage to the first output unit T (step S13). Next, the control unit 45 acquires current value information from the A / D conversion unit U (step S14), and determines whether or not the load current value indicated by the acquired current value information is equal to or less than the current threshold value (step S15).

[0086] When the control unit 45 determines that the load current value is equal to or less than the current threshold value (S15: YES), it changes the flag value to 1 (step S16) and causes the notification unit 43 to notify the occurrence of an OFF fault (step S17). As described above, the notification unit 43 performs notification by outputting a notification signal indicating the occurrence of an OFF fault. After executing step S17, the control unit 45 ends the first power supply control process.

[0087] When the control unit 45 determines that the load current value exceeds the current threshold value (S15: NO), it determines whether or not to stop the operation of the first load E (step S18). In step S18, if a stop signal indicating the first load E is input to the signal input unit 42, the control unit 45 determines to stop the operation of the first load E. When a stop signal indicating the first load E is not input to the signal input unit 42, the control unit 45 determines not to stop the operation of the first load E. When the control unit 45 determines not to stop the operation of the first load E (S18: NO), it executes step S18 again and waits until a stop signal indicating the first load E is input to the signal input unit 42.

[0088] When the control unit 45 determines that the operation of the first load E is to be stopped (S18: YES), it instructs the first output unit T to output a low-level voltage, thereby switching the first switch 20 to OFF (step S19). Next, the control unit 45 acquires current value information from the A / D conversion unit U (step S20), and determines whether or not the load current value indicated by the acquired current value information exceeds the current threshold (step S21). When the control unit 45 determines that the load current value exceeds the current threshold (S21: YES), it changes the value of the flag to 1 (step S22), and causes the notification unit 43 to notify the occurrence of an ON failure (step S23). As described above, the notification unit 43 performs notification by outputting a notification signal indicating the occurrence of an ON failure.

[0089] When the control unit 45 determines that the load current value is equal to or less than the current threshold value (S21: NO), or after executing step S23, the control unit 45 ends the first power supply control process. 。 After completing the first power supply control process, the control unit 45 executes the first power supply control process again. As described above, when the value of the flag is changed to 1, an instruction to switch the circuit switch 30 to OFF is issued in the switch control process.

[0090] <Second power supply control process> The second power supply control process is executed in a state where the second switch 31 is off. In the second power supply control process, the control unit 45 first determines whether or not to operate the second load F. If an operation signal indicating the second load F is input to the signal input unit 42, the control unit 45 determines to operate the second load F. If an operation signal indicating the second load F is not input to the signal input unit 42, the control unit 45 determines not to operate the second load F. If the control unit 45 determines not to operate the second load F, it waits until an operation signal indicating the second load F is input to the signal input unit 42.

[0091] When the control unit 45 determines to operate the second load F, it instructs the second drive circuit 33 to switch the second switch 31 on by causing the second output unit 41 to output a high-level voltage. As a result, the second switch 31 is switched on, and power is supplied to the second load F.

[0092] After instructing the second drive circuit 33 to switch the second switch 31 on, the control unit 45 determines whether or not to stop the operation of the second load F. When a stop signal indicating the second load F is input to the signal input unit 42, the control unit 45 stops the operation of the second load F. Stop If the stop signal indicating the second load F is not input to the signal input unit 42, the control unit 45 determines not to stop the operation of the second load F. If the control unit 45 determines not to stop the operation of the second load F, it waits until a stop signal indicating the second load F is input to the signal input unit 42.

[0093] When the control unit 45 determines to stop the operation of the second load F, it causes the second output unit 41 to output a low-level voltage, thereby instructing the second drive circuit 33 to switch the second switch 31 to OFF. This switches the second switch 31 to OFF, and stops the power supply to the second load F. After instructing the second drive circuit 33 to switch the second switch 31 to OFF, the control unit 45 ends the second power supply control process. After ending the second power supply control process, the control unit 45 executes the second power supply control process again.

[0094] <Operation example of power supply control device 10> Fig. 10 is a timing chart showing a first example of the operation of the power supply control device 10. Fig. 10 shows the transition of the state of the circuit switch 30, the transition of the instruction of the first switch 20, the transition of the value of the fault flag, and the transition of the load current value. The horizontal axis of these transitions shows time. The instruction of the first switch 20 includes an instruction to switch on and an instruction to switch off. In Fig. 10, the ignition switch is described as an IG switch. Ith indicates a current threshold value.

[0095] The first example of the operation of the power supply control device 10 is an example of operation in the case where neither an ON failure nor an OFF failure occurs in the first switch 20. As shown in Fig. 10, when the ignition switch of the vehicle C is switched on, the switch drive circuit 32 switches the circuit switch 30 on. When the ignition switch of the vehicle C is switched off, the switch drive circuit 32 switches the circuit switch 30 off.

[0096] The value of the fault flag is zero when neither an OFF fault nor an ON fault occurs in the first switch 20. When the first switch 20 is off, the load current value is zero A, which is equal to or less than the current threshold Ith.

[0097] The activation signal and the stop signal are each input to the signal input unit 42 while the ignition switch is on. Therefore, the control unit 45 instructs the first drive circuit 21 to switch the first switch 20 on or off while the circuit switch 30 is on. When an activation signal indicating the first load E is input to the signal input unit 42, the control unit 45 instructs the first drive circuit 21 to switch the first switch 20 on. As a result, the first drive circuit 21 switches the first switch 20 on. As a result, the load current value exceeds the current threshold Ith, and the first load E is activated.

[0098] When a stop signal indicating the first load E is input to the signal input unit 42, the control unit 45 instructs the first drive circuit 21 to switch off the first switch 20. As a result, the first drive circuit 21 switches off the first switch 20. As a result, the load current value drops to zero A, and the first load E stops operating.

[0099] Fig. 11 is a timing chart showing a second example of the operation of the power supply control device 10. In Fig. 11, similar to Fig. 10, the transition of the state of the circuit switch 30, the transition of the instruction of the first switch 20, the transition of the value of the fault flag, and the transition of the load current value are shown. The horizontal axis of these transitions indicates time. As described above, the IG switch is an ignition switch. Ith indicates a current threshold value.

[0100] A second example of the operation of the power supply control device 10 is an example of operation when an on-failure occurs in the first switch 20. As shown in Fig. 11, when the ignition switch of the vehicle C is switched on, the switch drive circuit 32 switches the circuit switch 30 on. When neither an off-failure nor an on-failure occurs in the first switch 20, the value of the fault flag is zero. When the first switch 20 is off, the load current value is zero A, which is equal to or less than the current threshold value Ith.

[0101] With the circuit switch 30 on, the control unit 45 instructs the first drive circuit 21 to switch the first switch 20 on or off. When an actuation signal indicating the first load E is input to the signal input unit 42, the control unit 45 instructs the first drive circuit 21 to switch the first switch 20 on. As a result, the first drive circuit 21 switches the first switch 20 on. As a result, the first load E is actuated, and the load current value exceeds the current threshold Ith.

[0102] Assume that while the first switch 20 is on, the voltage output to the first drive circuit 21 is fixed to a high-level voltage and an on-fault occurs. When a stop signal indicating the first load E is input to the signal input unit 42, the control unit 45 instructs the first drive circuit 21 to switch the first switch 20 off. However, since an on-fault occurs, the load current value does not decrease to a value equal to or lower than the current threshold value Ith.

[0103] The control unit 45 detects the occurrence of an ON fault because the load current value exceeds the current threshold Ith despite having instructed to switch the first switch 20 OFF. When the control unit 45 detects an ON fault, it changes the flag value to 1 in the first power supply control process, and instructs the switch drive circuit 32 to switch the circuit switch 30 OFF in the switch control process. This switches the circuit switch 30 OFF. As a result, the load current value drops to zero A, and the operation of the first load E stops.

[0104] <Effects of the power supply control device 10> In the power supply control device 10, the first controller G and the second controller H are formed on the first board B1 and the second board B2, respectively. Therefore, the first controller G can be easily changed according to the first load E. By combining various first controllers G with a common second controller H, a configuration corresponding to the first load E whose operation is controlled can be realized. Furthermore, when an ON failure occurs in the first switch 20, the power supply to the first load E can be stopped by switching off the circuit switch 30 of the second controller H.

[0105] Furthermore, in the second controller H, the switch drive circuit 32 switches the circuit switch 30 off, thereby stopping the power supply to the first drive circuit 21 and the current output unit 22 of the first controller G. When the ignition switch is switched off, the circuit switch 30 is switched off. This allows the first drive circuit 21 and the current output unit 22 to consume power efficiently.

[0106] (Embodiment 2) In embodiment 1, when the control unit 45 of the second controller H detects an on-failure or an off-failure of the first switch 20, the timing of switching the circuit switch 30 off is not limited to immediately after detecting the on-failure or off-failure of the first switch 20. The following describes the differences between embodiment 2 and embodiment 1. Configurations other than those described below are common to embodiment 1. For this reason, components common to embodiment 1 are given the same reference numerals as embodiment 1, and descriptions of those components are omitted.

[0107] When comparing the first and second embodiments, the switch control process and the first power supply control process performed by the control unit 45 of the second controller H are different. The switch control process and the first power supply control process in the second embodiment will be described below.

[0108] <Switch control processing> 12 is a flowchart showing the procedure of the switch control process in embodiment 2. The switch control process in embodiment 2 is executed in a state where the circuit switch 30 is off, similar to the switch control process in embodiment 1. A part of the switch control process in embodiment 2 is similar to a part of the switch control process in embodiment 1. Therefore, in the switch control process in embodiment 2, detailed description of steps S1 to S4 and S6 common to the switch control process in embodiment 1 will be omitted.

[0109] If the control unit 45 determines that the ignition switch is not switched off (S4: NO), it executes step S4 again and waits until the ignition switch is switched off. If the control unit 45 determines that the ignition switch is switched off (S4: YES), it executes step S6. In step S6, the control unit 45 instructs the switch drive circuit 32 to switch the circuit switch 30 off by causing the voltage output unit 40 to output a low-level voltage.

[0110] As described above, in the second embodiment, when the ignition switch is switched off after the circuit switch 30 is switched on, the switch drive circuit 32 switches off the circuit switch 30. Even if the value of the failure flag is changed to 1 while the circuit switch 30 is on, the switch drive circuit 32 does not switch off the circuit switch 30.

[0111] <First power supply control process> 13 is a flowchart showing the procedure of the first power supply control process. The first power supply control process in the second embodiment is executed in a state where the first switch 20 is off, similarly to the first embodiment. In the first power supply control process in the second embodiment, the control unit 45 executes steps S11 to S23 in the same manner as the first embodiment. For this reason, detailed description of steps S11 to S23 will be omitted. In the first power supply control process in the second embodiment, the control unit 45 executes two processes in addition to steps S11 to S23.

[0112] As described in the description of the first embodiment, the control unit 45 executes step S15 while instructing to switch the first switch 20 on. When the control unit 45 determines that the load current value is equal to or less than the current threshold value (S15: YES), the control unit 45 instructs to switch the first switch 20 off by causing the first output unit T to output a low-level voltage (step S31).

[0113] When step S15 is executed, the load current value being equal to or less than the current threshold means that an OFF fault has occurred in the first switch 20. When the control unit 45 determines that the load current value is equal to or less than the current threshold, the first drive circuit 21 is instructed to switch the first switch 20 to ON. When an OFF fault has occurred, the control unit 45 instructs the first switch 20 to be switched to OFF in order to keep the first switch 20 OFF until the ignition switch is switched OFF. The control unit 45 executes step S31 and then executes step S16. In step S16, the value of the flag is changed to 1.

[0114] As described in the description of the first embodiment, the control unit 45 executes step S21 in a state in which it instructs to switch the first switch 20 to OFF. When it is determined that the load current value exceeds the current threshold value (S21: YES), the control unit 45 instructs to switch the first switch 20 to ON by causing the first output unit T to output a high-level voltage (step S32).

[0115] At the time when step S15 is executed, the load current value exceeds the current threshold value, which means that an ON fault has occurred in the first switch 20. At the time when the control unit 45 determines that the load current value exceeds the current threshold value, the first drive circuit 21 is instructed to switch the first switch 20 to OFF. When an ON fault occurs, the control unit 45 instructs the first switch 20 to be switched to ON in order to keep the first switch 20 ON until the ignition switch is switched OFF. The control unit 45 executes step S32 and then executes step S22. In step S22, the value of the flag is changed to 1.

[0116] <Operation example of power supply control device 10> Fig. 14 is a timing chart showing an example of operation of the power supply control device 10. Fig. 14 shows an example of operation when an on-failure occurs in the first switch 20. Therefore, Fig. 14 corresponds to Fig. 11. Like Fig. 11, Fig. 14 shows the transition of the state of the circuit switch 30, the transition of the instruction of the first switch 20, the transition of the value of the fault flag, and the transition of the load current value. As described in the explanation of the first embodiment, the IG switch is an ignition switch. Ith indicates a current threshold value.

[0117] 14, when the ignition switch of the vehicle C is turned on, the switch drive circuit 32 turns on the circuit switch 30. When neither an off fault nor an on fault occurs in the first switch 20, the value of the fault flag is zero. When the first switch 20 is off, the load current value is zero A, which is equal to or less than the current threshold value Ith.

[0118] With the circuit switch 30 on, the control unit 45 instructs the first drive circuit 21 to switch the first switch 20 on or off. When an actuation signal indicating the first load E is input to the signal input unit 42, the control unit 45 instructs the first drive circuit 21 to switch the first switch 20 on. As a result, the first drive circuit 21 switches the first switch 20 on. As a result, the first load E is actuated, and the load current value exceeds the current threshold Ith.

[0119] Assume that while the first switch 20 is on, the voltage output to the first drive circuit 21 is fixed to a high-level voltage and an on-fault occurs. When a stop signal indicating the first load E is input to the signal input unit 42, the control unit 45 instructs the first drive circuit 21 to switch the first switch 20 off. However, since an on-fault occurs, the load current value does not decrease to a value equal to or lower than the current threshold value Ith.

[0120] The control unit 45 detects the occurrence of an on-failure because the load current value exceeds the current threshold value Ith despite having instructed the first switch 20 to be switched off. When the control unit 45 detects an on-failure, in the first power supply control process, the control unit 45 instructs the first drive circuit 21 to switch the first switch 20 on and changes the value of the flag to 1. When the ignition switch is switched off, the control unit 45 instructs the switch drive circuit 32 to switch the circuit switch 30 off in the switch control process. This switches the circuit switch 30 off. As a result, the load current value drops to zero A and the operation of the first load E stops.

[0121] The first load E in the second embodiment is an electric device that is required to continue operating when it is impossible to operate again. The first load E in the second embodiment is, for example, a headlight. When the ignition switch is turned off, that is, when the driving of the vehicle C is finished, the operation of the first load E is stopped.

[0122] <Effects of the power supply control device 10> In the power supply control device 10 in the second embodiment, when an ON failure occurs in the first switch 20, the circuit switch 30 is kept ON until the ignition switch is switched OFF, and the operation of the first load E is continued. When the ignition switch is switched OFF, the switch drive circuit 32 switches the circuit switch 30 OFF, and stops power supply to the first load E. The power supply control device 10 in the second embodiment achieves the same effects as the power supply control device 10 in the first embodiment.

[0123] (Embodiment 3) In the first embodiment, the circuit switch 30 is switched on when the ignition switch of the vehicle C is switched on. However, the timing at which the circuit switch 30 is switched on is not limited to the timing at which the ignition switch is switched on. The following describes the differences between embodiment 3 and embodiment 1. Except for the configuration described below, other configurations are common to embodiment 1. Therefore, components common to embodiment 1 are given the same reference numerals as embodiment 1, and descriptions of those components are omitted.

[0124] <Configuration of Microcomputer 34> In the microcomputer 34 in the third embodiment, the processing element of the control unit 45 does not execute the switch control process. When comparing the first and third embodiments, the contents of the first power supply control process are different. The first power supply control process in the third embodiment will be described below.

[0125] <First power supply control process> 15 and 16 are flowcharts showing the procedure of the first power supply control process. The first power supply control process in the third embodiment is executed in a state where the first switch 20 is off, as in the first embodiment. A part of the first power supply control process in the third embodiment is common to a part of the first power supply control process in the first embodiment. Therefore, in the first power supply control process in the third embodiment, explanations of steps S11, S12, and S14 to S23 that are common to the first power supply control process in the first embodiment will be omitted.

[0126] When the control unit 45 determines that the value of the failure flag is not zero (S11: NO), it determines whether or not the ignition switch of the vehicle C is on based on the ignition signal input to the signal input unit 42 (step S41). When the control unit 45 determines that the ignition switch is not on (S41: NO), it executes step S41 again and waits until the ignition switch is switched on. When the control unit 45 determines that the ignition switch is on (S41: YES), it executes step S12.

[0127] When the control unit 45 determines that the first load E is to be operated (S12: YES), it instructs the switch drive circuit 32 and the first drive circuit 21 to switch on the circuit switch 30 and the first switch 20, respectively (step S42). The control unit 45 causes the voltage output unit 40 to output a high-level voltage, thereby instructing the switch drive circuit 32 to switch on the circuit switch 30. As in the first embodiment, the control unit 45 causes the first output unit T to output a high-level voltage, thereby instructing the first drive circuit 21 to switch on the first switch 20. After executing step S42, the control unit 45 executes step S14.

[0128] The control unit 45 executes step S15 while instructing the circuit switch 30 and the first switch 20 to be switched on. When the control unit 45 determines that the load current value is equal to or less than the current threshold value (S15: YES), it instructs the switch drive circuit 32 and the first drive circuit 21 to switch the circuit switch 30 and the first switch 20 to be switched off (step S43). The control unit 45 instructs the switch drive circuit 32 to switch the circuit switch 30 to be switched off by making the voltage output unit 40 output a low-level voltage. The control unit 45 instructs the first drive circuit 21 to switch the first switch 20 to be switched off by making the first output unit T output a low-level voltage, as in the first embodiment. After executing step S43, the control unit 45 executes step S16.

[0129] As described in the description of the first embodiment, the control unit 45 executes step S21 while instructing to switch the first switch 20 to OFF. When the control unit 45 determines that the load current value is equal to or less than the current threshold value (S21: NO), or after executing step S23, the control unit 45 instructs to switch the circuit switch 30 to OFF (step S44). After executing step S44, the control unit 45 ends the first power supply control process.

[0130] <Operation example of power supply control device 10> Fig. 17 is a timing chart showing a first example of the operation of the power supply control device 10. Fig. 17 corresponds to Fig. 10. Fig. 17 shows the transition of the state of the circuit switch 30, the transition of the instruction of the first switch 20, the transition of the value of the fault flag, and the transition of the load current value, similarly to Fig. 10. As described in the explanation of the first embodiment, the IG switch is an ignition switch. Ith indicates a current threshold value.

[0131] The first example of the operation of the power supply control device 10 is an example of operation in the case where neither an ON fault nor an OFF fault occurs in the first switch 20. When neither an OFF fault nor an ON fault occurs in the first switch 20, the value of the fault flag is zero. When the first switch 20 or the circuit switch 30 is off, the load current value is zero A, which is equal to or less than the current threshold value Ith.

[0132] When an actuation signal indicating the first load E is input to the signal input unit 42, the control unit 45 instructs the switch drive circuit 32 and the first drive circuit 21 to respectively switch on the circuit switch 30 and the first switch 20. As a result, the circuit switch 30 and the first switch 20 are switched on. As a result, a current flows from the positive electrode of the DC power supply 11 through the circuit switch 30, the first switch 20, and the first load E in that order. The load current value exceeds the current threshold Ith, and the first load E is actuated.

[0133] When a stop signal indicating the first load E is input to the signal input unit 42, the control unit 45 instructs the first drive circuit 21 to switch the first switch 20 off. As a result, the first drive circuit 21 switches the first switch 20 off. As a result, the load current value drops to zero A, and the first load E stops operating. After confirming that the load current value has become equal to or less than the current threshold value Ith, the control unit 45 instructs the switch drive circuit 32 to switch the circuit switch 30 off. As a result, the circuit switch 30 is switched off.

[0134] Fig. 18 is a timing chart showing a second example of the operation of the power supply control device 10. Fig. 18 corresponds to Fig. 11. Fig. 18 shows, as in Fig. 11, the transition of the state of the circuit switch 30, the transition of the instruction of the first switch 20, the transition of the value of the fault flag, and the transition of the load current value. As described above, the IG switch is an ignition switch. Ith indicates a current threshold value.

[0135] A second example of the operation of the power supply control device 10 is an example of operation when an on-fault occurs in the first switch 20. When neither an off-fault nor an on-fault occurs in the first switch 20, the value of the fault flag is zero. When the first switch 20 or the circuit switch 30 is off, the load current value is zero A, which is equal to or less than the current threshold value Ith.

[0136] As described above, when an actuation signal indicating the first load E is input to the signal input unit 42, the control unit 45 instructs the switch drive circuit 32 and the first drive circuit 21 to respectively switch on the circuit switch 30 and the first switch 20. This switches on the circuit switch 30 and the first switch 20. As a result, the first load E is actuated, and the load current value exceeds the current threshold Ith.

[0137] Assume that while the first switch 20 is on, the voltage output to the first drive circuit 21 is fixed to a high-level voltage and an on-fault occurs. When a stop signal indicating the first load E is input to the signal input unit 42, the control unit 45 instructs the first drive circuit 21 to switch the first switch 20 off. However, since an on-fault occurs, the load current value does not decrease to a value equal to or lower than the current threshold value Ith.

[0138] The control unit 45 detects the occurrence of an ON fault because the load current value exceeds the current threshold Ith despite having instructed to turn off the first switch 20. When the control unit 45 detects an ON fault, it instructs the switch drive circuit 32 to turn off the circuit switch 30 and changes the value of the flag to 1. As a result, the load current value falls to zero A, and the operation of the first load E stops.

[0139] <Effects of the power supply control device 10> The power supply control device 10 in the third embodiment achieves the same effects as the power supply control device 10 in the first embodiment.

[0140] (Embodiment 4) In embodiment 3, when the control unit 45 of the second controller H detects an on-failure or an off-failure of the first switch 20, the timing of switching the circuit switch 30 off is not limited to immediately after detecting the on-failure or off-failure of the first switch 20. The following describes the differences between the fourth embodiment and the third embodiment. Except for the configuration described below, the other configurations are the same as those of the third embodiment. Therefore, the same reference numerals as those of the third embodiment are used for the components that are the same as those of the third embodiment, and the description of those components is omitted.

[0141] When comparing the third and fourth embodiments, the content of the first power supply control process performed by the control unit 45 of the second controller H is different. The first power supply control process in the fourth embodiment will be described below.

[0142] <First power supply control process> 19 is a flowchart showing the procedure of the first power supply control process. The first power supply control process in the fourth embodiment is executed in a state where the first switch 20 is off, similarly to the third embodiment. In the first power supply control process in the fourth embodiment, the control unit 45 executes steps S11, S12, S14 to S23, and S41 to S44 in the same manner as the first power supply control process in the third embodiment. Therefore, detailed explanations of steps S11, S12, S14 to S23, and S41 to S44 will be omitted. In the first power supply control process in the fourth embodiment, the control unit 45 executes two processes in addition to steps S11, S12, S14 to S23, and S41 to S44.

[0143] As described in the first and third embodiments, the control unit 45 executes step S21 while instructing to switch the first switch 20 off. When the control unit 45 determines that the load current value exceeds the current threshold (S21: YES), the control unit 45 causes the first output unit T to output a high-level voltage, thereby instructing to switch the first switch 20 on (step S51). After executing step S51, the control unit 45 executes step S22.

[0144] After executing step S23, the control unit 45 determines whether or not the ignition switch of the vehicle C has been switched off based on the ignition signal input to the signal input unit 42 (step S52). If the control unit 45 determines that the ignition switch has not been switched off (S52: NO), it executes step S52 again and waits until the ignition switch is switched off. If the control unit 45 determines that the load current value is equal to or less than the current threshold value (S21: NO) or determines that the ignition switch has been switched off (S52: YES), it executes step S 44 Execute.

[0145] <Operation example of power supply control device 10> Fig. 20 is a timing chart showing an example of operation of the power supply control device 10. Fig. 20 shows an example of operation when an on-failure occurs in the first switch 20. Therefore, Fig. 20 corresponds to Fig. 18. Like Fig. 18, Fig. 20 shows the transition of the state of the circuit switch 30, the transition of the instruction of the first switch 20, the transition of the value of the fault flag, and the transition of the load current value. As described in the explanation of the first embodiment, the IG switch is an ignition switch. Ith indicates a current threshold value.

[0146] The value of the fault flag is zero when neither an OFF fault nor an ON fault occurs in the first switch 20. When the first switch 20 or the circuit switch 30 is off, the load current value is zero A, which is equal to or less than the current threshold Ith.

[0147] As described in the first and third embodiments, when an actuation signal indicating the first load E is input to the signal input unit 42, the control unit 45 instructs the switch drive circuit 32 and the first drive circuit 21 to respectively switch on the circuit switch 30 and the first switch 20. This switches on the circuit switch 30 and the first switch 20. As a result, the first load E is actuated, and the load current value exceeds the current threshold Ith.

[0148] Assume that while the first switch 20 is on, the voltage output to the first drive circuit 21 is fixed to a high-level voltage and an on-fault occurs. When a stop signal indicating the first load E is input to the signal input unit 42, the control unit 45 instructs the first drive circuit 21 to switch the first switch 20 off. However, since an on-fault occurs, the load current value does not decrease to a value equal to or lower than the current threshold value Ith.

[0149] The control unit 45 detects the occurrence of an ON fault because the load current value exceeds the current threshold Ith despite the instruction to switch the first switch 20 OFF. When the control unit 45 detects an ON fault, it instructs the first drive circuit 21 to switch the first switch 20 ON and changes the value of the flag to 1. After that, the control unit 45 waits until the ignition switch is switched ON while keeping the circuit switch 30 ON. When the ignition switch is switched OFF, the control unit 45 instructs the switch drive circuit 32 to switch the circuit switch 30 OFF. This switches the circuit switch 30 OFF. As a result, the load current value drops to zero A, and the operation of the first load E stops.

[0150] The first load E in the fourth embodiment is an electric device that is required to continue operating when re-operation is impossible, similar to the first load E in the first embodiment. If an on-failure occurs in the first switch 20, the operation of the first load E is stopped when the ignition switch is switched off, that is, when the operation of the vehicle C is terminated.

[0151] <Effects of the power supply control device 10> In the power supply control device 10 in the fourth embodiment, when an ON failure occurs in the first switch 20, the circuit switch 30 is kept ON until the ignition switch is switched OFF, thereby continuing the operation of the first load E. When the ignition switch is switched OFF, the switch drive circuit 32 switches the circuit switch 30 OFF, thereby stopping the power supply to the first load E. The power supply control device 10 in the fourth embodiment achieves the same effects as the power supply control device 10 in the third embodiment.

[0152] (Embodiment 5) In the first embodiment, the number of first loads E for which the power supply control device 10 controls power supply is 1. However, the number of first loads E for which the power supply control device 10 controls power supply is not limited to 1. The following describes the differences between embodiment 5 and embodiment 1. Except for the configuration described below, other configurations are common to embodiment 1. For this reason, components common to embodiment 1 are given the same reference numerals as embodiment 1, and descriptions of those components are omitted.

[0153] <Power supply system 1 configuration> FIG. 21 is a block diagram showing a configuration of a main part of a power supply system 1 in embodiment 5. The power supply system 1 in embodiment 5 includes components other than the first load E included in the components included in the power supply system 1 in embodiment 1. The power supply system 1 in embodiment 5 includes n first loads E1, E2, ..., En instead of the first load E. Here, n is an integer of 2 or more. Hereinafter, any integer greater than or equal to 1 and less than or equal to n will be represented as i. Therefore, i may be any integer in the range greater than or equal to 1 and less than or equal to n.

[0154] The power supply control device 10 is connected to one end of each of the first loads Ei. The other end of the first load Ei is grounded. A DC power source 11 supplies power to the first loads Ei via the power supply control device 10. The power supply control device 10 controls power supply to the n first loads E1, E2, ..., En and the second load F separately. The activation signal indicates which of the n first loads E1, E2, ..., En and the second load F is to be activated. The stop signal indicates which of the n first loads E1, E2, ..., En and the second load F is to be stopped.

[0155] <Configuration of power supply control device 10> The power supply control device 10 in the fifth embodiment has components other than the first controller G among the components of the power supply control device 10 in the first embodiment. The power supply control device 10 in the fifth embodiment has n first controllers G1, G2, . . . , Gn instead of the first controller G. The first controller Gi is configured similarly to the first controller G in the first embodiment. Therefore, the first controller Gi has a first switch 20. In the first controller Gi, the source of the first switch 20 is connected to one end of the first load Ei. The drain of the first switch 20 is connected to the source of the circuit switch 30 of the second controller H. The first controllers G1, G2, . . . , Gn are formed on n first substrates B1.

[0156] When both the first switch 20 of the first controller Gi and the circuit switch 30 of the second controller H are on, a current flows from the positive electrode of the DC power supply 11 through the circuit switch 30, the first switch 20, and the first load Ei in this order. This supplies power to the first load Ei. As described above, the circuit switch 30 and the first switch 20 are disposed in the current path of the current flowing through the first load Ei.

[0157] When the circuit switch 30 and the n first switches 20 are on, the current flowing through the circuit switch 30 is divided into n currents. Each of these currents flows through the n first loads E1, E2, . . . , En. When at least one of the first switch 20 of the first controller Gi and the circuit switch 30 of the second controller H is off, no current flows through the first load Ei. At this time, power supply to the first load Ei is stopped.

[0158] The second controller H instructs the first controller Gi on an operation related to power supply to the first load Ei while the circuit switch 30 is on. The second controller H instructs the first controller Gi to turn on or off the first switch 20 as an operation related to power supply to the first load Ei. The first controller Gi switches the first switch 20 on or off according to the instruction of the second controller H. This controls the power supply to the first load Ei.

[0159] The first controller Gi is configured similarly to the first controller G in embodiment 1. The operation performed by the second controller H with respect to the first controller Gi is similar to the operation performed by the second controller H with respect to the first controller G in embodiment 1.

[0160] <Configuration of the microcomputer 34 of the second controller H> 22 is a block diagram showing the main configuration of the microcomputer 34. The microcomputer 34 in the fifth embodiment has components other than the first output unit T and the A / D conversion unit U among the components of the microcomputer 34 in the first embodiment. The microcomputer 34 in the fifth embodiment has n first output units T1, T2, . . . , Tn instead of the first output unit T. Furthermore, the microcomputer 34 in the fifth embodiment has n A / D conversion units U1, U2, . . . , Un instead of the A / D conversion unit U. The first output unit Ti and the A / D conversion unit Ui are connected to the internal bus 46. The first output unit Ti is further connected to the first drive circuit 21 of the first controller Gi. The A / D conversion unit Ui is further connected to a connection node between the current output unit 22 and the resistor 23 of the first controller Gi.

[0161] The first output unit Ti acts in the same manner as the first output unit T in the first embodiment. Therefore, the control unit 45 instructs the first switch 20 of the first controller Gi to be switched on or off by causing the first output unit Ti to output a high-level voltage or a low-level voltage. The A / D conversion unit Ui acts in the same manner as the A / D conversion unit Ui in the first embodiment. Therefore, the control unit 45 acquires current value information from the A / D conversion unit Ui. The current value information acquired from the A / D conversion unit Ui indicates the load current value of the current flowing through the first switch 20 and the first load Ei of the first controller Gi.

[0162] The processing elements of the control unit 45 execute the computer program P to execute the switch control process, the n first power supply control processes, and the second power supply control process. The control unit 45 executes the switch control process and the second power supply control process in the same manner as in embodiment 1. A fault flag value of zero means that no on-failure or off-failure has occurred in any of the first switches 20. A fault flag value of 1 means that an on-failure or off-failure has occurred in at least one of the n first switches 20.

[0163] Each of the n first power supply control processes is a process for controlling power supply to the n first loads E1, E2, . . . , En. The control unit 45 executes each of the n first power supply control processes in the same manner as the first power supply control process in the first embodiment. In the first power supply control process of the first load Ei, the control unit 45 determines whether to operate the first load Ei based on whether an operation signal indicating the first load Ei has been input. The control unit 45 determines whether to stop the operation of the first load Ei based on whether a stop signal indicating the first load Ei has been input. The control unit 45 instructs the first switch 20 of the first controller Gi to be switched on or off. The control unit 45 acquires current value information from the A / D conversion unit Ui.

[0164] Each of the first loads E1, E2, ..., En is an electric device that does not interfere with the operation of the vehicle C even when it is constantly stopped. Therefore, when an ON failure or an OFF failure occurs in at least one of the n first switches 20, the control unit 45 instructs the circuit switch 30 to be switched OFF. As a result, the switch drive circuit 32 switches the circuit switch 30 OFF.

[0165] <Effects of the power supply control device 10> In the power supply control device 10 in the fifth embodiment, a circuit switch 30 is disposed upstream of the n first switches 20. By switching off the circuit switch 30, it is possible to stop power supply to the n first loads E1, E2, . . . , En. The power supply control device 10 in the fifth embodiment achieves the same effects as the power supply control device 10 in the first embodiment.

[0166] (Embodiment 6) In embodiment 5, when the control unit 45 of the second controller H detects an on-failure or off-failure of at least one of the n first switches 20, the timing of switching the circuit switch 30 off is not limited to immediately after detecting the on-failure or off-failure of the first switch 20. The following describes the differences between the sixth embodiment and the fifth embodiment. Except for the configuration described below, the sixth embodiment is the same as the fifth embodiment. Therefore, the components common to the fifth embodiment are given the same reference numerals as the fifth embodiment, and the description of those components is omitted.

[0167] Comparing the fifth and sixth embodiments, the contents of the switch control process and the n first power supply control processes performed by the control unit 45 of the second controller H are different. In the sixth embodiment, the control unit 45 executes the switch control process and the second power supply control process in the same manner as in the second embodiment.

[0168] The control unit 45 executes each of the n first power supply control processes in the same manner as the first power supply control processes in the second embodiment. In the first power supply control process of the first load Ei, the control unit 45 determines whether to operate the first load Ei based on whether an activation signal indicating the first load Ei has been input. The control unit 45 determines whether to stop the operation of the first load Ei based on whether a stop signal indicating the first load Ei has been input. The control unit 45 instructs the first switch 20 of the first controller Gi to be switched on or off. The control unit 45 acquires current value information from the A / D conversion unit Ui.

[0169] In the sixth embodiment, when an ON failure or an OFF failure occurs in at least one of the n first switches 20, the control unit 45 keeps the circuit switch 30 ON until the ignition switch is switched OFF. In the sixth embodiment, the n first loads E1, E2, ..., En include electric devices that are required to continue operating when re-operation is not possible.

[0170] <Effects of the power supply control device 10> The power supply control device 10 in the sixth embodiment achieves the same effects as the power supply control device 10 in the fifth embodiment.

[0171] <Modification> In the first to sixth embodiments, the power supply system 1 does not have to include the second load F. In this case, the second controller H of the power supply control device 10 does not have the second switch 31 and the second drive circuit 33. In this case, the second switch 31 and the second drive circuit 33 are not arranged on the second board B2.

[0172] In the fifth and sixth embodiments, when an OFF failure occurs in the n first switches 20, the value of the failure flag may be maintained at zero without changing the value of the failure flag to 1. In this case, the control unit 45 changes the value of the failure flag to 1 only when an ON failure occurs in at least one of the n first switches 20.

[0173] In the second, fourth and sixth embodiments, when the control unit 45 detects the occurrence of an on-failure or an off-failure, the control unit 45 instructs the circuit switch 30 to be switched off when the ignition switch is switched off. Here, the timing at which the control unit 45 instructs the circuit switch 30 to be switched off is not limited to the timing at which the ignition switch is switched off, but may be any timing at which the vehicle C stops traveling. For this reason, the timing at which the control unit 45 instructs the circuit switch 30 to be switched off may be the timing at which the vehicle C is parked. The control unit 45 can determine whether or not the vehicle C is parked, for example, based on the position of the shift lever of the vehicle C.

[0174] In the first drive circuit 21 in the first to sixth embodiments, the location to which the current input terminal for supplying power is connected is not limited to a position downstream of the circuit switch 30, and may be a position upstream of the circuit switch 30. In this configuration, the DC power supply 11 constantly supplies power to the first drive circuit 21.

[0175] In the first to sixth embodiments, the first drive circuit 21 may switch the first switch 20 on when the voltage output to the first drive circuit 21 is switched to a low-level voltage. In this case, the first drive circuit 21 switches the first switch 20 off when the voltage output to the first drive circuit 21 is switched to a high-level voltage. In this configuration, the control unit 45 instructs the first switch 20 to be switched on by causing the first output unit T or the first output unit Ti to output a low-level voltage. Similarly, the control unit 45 instructs the first switch 20 to be switched off by causing the first output unit T or the first output unit Ti to output a high-level voltage.

[0176] When the connection line connecting the first drive circuit 21 and the microcomputer 34 is grounded, the voltage output to the first drive circuit 21 is fixed to a low level voltage. In this case, in the configuration described above, an ON fault occurs. When the connection line connecting the first drive circuit 21 and the microcomputer 34 is electrically connected to the connection line connecting the first switch 20 and the circuit switch 30 while the circuit switch 30 is on, the voltage output to the first drive circuit 21 is fixed to a high level voltage. In this case, in the configuration described above, an OFF fault occurs.

[0177] In the first to sixth embodiments, the control unit 45 may detect an on-failure or an off-failure of the second switch 31, similarly to the first switch 20, based on the current value of the current flowing through the second switch 31. Also, the first switch 20, the circuit switch 30, and the second switch 31 are not limited to N-channel FETs as long as they function as switches. The first switch 20, the circuit switch 30, and the second switch 31 may be P-channel FETs, bipolar transistors, relay contacts, or the like.

[0178] The disclosed embodiments 1 to 6 are illustrative in all respects and should not be considered as limiting. The scope of the present invention is defined by the claims, not by the above meaning, and is intended to include all modifications within the scope and meaning equivalent to the claims. [Explanation of symbols]

[0179] 1 Power System 10 Power supply control device 11 DC power supply 20 First switch (load switch) 21 First drive circuit (switching circuit) 22 Current output section 23 Resistance 30 Circuit Switch 31 Second Switch 32 Switch driver circuit 33 Second drive circuit 34 Microcomputer 40 Voltage output section 41 Second output section 42 Signal input section 43 Notification Department 44 Memory section 45 Control section (processing section) 46 Internal Bus A storage medium B1 First board B2 Second board C Vehicle E,E1,E2,...,En 1st load F 2nd load G, G1, G2, , Gn First controller (controller) H Second controller (indicator) P Computer Program T, T1, T2, , Tn First output section U,U1,U2,...,Un A / D conversion section

Claims

1. A power supply control device for a vehicle that controls power supply to a load, A controller formed on a first substrate and configured to control power supply to the load; an indicator formed on a second substrate different from the first substrate, the indicator instructing the controller on an operation related to the power supply; Equipped with The controller includes a load switch disposed in a current path of a current flowing through the load; The indicator is a circuit switch disposed in the current path; A processing unit for executing processing; having The processing unit instructs the load switch to be switched on or off. Power supply control device.

2. The processing unit of the indicator Instructing the load switch to be switched off while the circuit switch is on; acquiring a current value of a current flowing through the current path after instructing to switch off the load switch; determining whether the acquired current value exceeds a current threshold; When it is determined that the current value exceeds the current threshold, an instruction is given to switch off the circuit switch. The power supply control device according to claim 1 .

3. The processing unit of the indicator determining whether an ignition switch of the vehicle has been turned off; When it is determined that the current value exceeds the current threshold value and an ignition switch of the vehicle is switched off, an instruction is given to switch off the circuit switch. The power supply control device according to claim 2 .

4. The number of each of the loads and the load switches is two or more; A plurality of load switches are disposed in current paths of a plurality of currents flowing through a plurality of loads, The current flowing through the circuit switch is divided into the multiple currents. The power supply control device according to any one of claims 1 to 3.

5. the controller includes a switching circuit for switching the load switch on or off; The current flows through the circuit switch and the load switch in that order. Power is supplied to the switching circuit via the circuit switch; The processing unit of the indicator instructs the circuit switch to be switched off when an ignition switch of the vehicle is switched off. The power supply control device according to any one of claims 1 to 4.

6. A power supply control method for a power supply control device for a vehicle, comprising: a controller formed on a first substrate and controlling power supply to a load; and an indicator formed on a second substrate different from the first substrate and instructing the controller on an operation related to the power supply, the controller having a load switch disposed in a current path of a current flowing through the load, and the indicator having a circuit switch disposed in the current path, instructing the load switch to be switched off while the circuit switch is on; acquiring a current value of a current flowing through the current path after instructing to turn off the load switch; determining whether the acquired current value exceeds a current threshold; instructing the circuit switch to be switched off when it is determined that the current value exceeds the current threshold value; The computer executes the power supply control method.

7. A computer program for causing a computer to control power supply in a power supply control device for a vehicle, the computer program comprising: a controller formed on a first substrate and controlling power supply to a load; and an indicator formed on a second substrate different from the first substrate and instructing the controller on an operation related to the power supply, the controller having a load switch disposed in a current path of a current flowing through the load, and the indicator having a circuit switch disposed in the current path, On the computer, instructing the load switch to be switched off while the circuit switch is on; acquiring a current value of a current flowing through the current path after instructing to turn off the load switch; determining whether the acquired current value exceeds a current threshold; instructing the circuit switch to be switched off when it is determined that the current value exceeds the current threshold value; A computer program that executes the following:

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