Power supply device

Abstract

In a power supply device that allows easy attachment and detachment of equipment using a connector, an excessive current is prevented from flowing through the power supply device when the power supply device is connected to the equipment, regardless of whether the equipment is faulty or has a configuration. [Solution] The device comprises a main power supply 110 capable of supplying DC power, two or more connectors 120 capable of supplying power from the main power supply 110 without power conversion, and a control unit 150 that switches the connection state between the main power supply 110 and the connectors 120, wherein the control unit 150 switches the connection state between a first state in which the main power supply 110 and the connectors 120 are not connected, a second state in which the main power supply 110 and the connectors 120 are connected via a resistor 141, and a third state in which the main power supply 110 and the connectors 120 are connected without via the resistor 141.

Description

[Technical Field]

[0001] The present disclosure relates to a power supply device. [Background technology]

[0002] When connecting a power supply device to a device, an excessive current (so-called inrush current) may flow when the power is turned on. This occurs, for example, when the device is equipped with a large-capacity smoothing capacitor or decoupling capacitor, and a current flows first to charge these capacitors when the power is turned on. To prevent failures caused by such inrush current, a current limiting means (e.g., a current limiting circuit) that limits the current supplied to the device may be provided.

[0003] Patent Document 1 discloses a DC / DC converter that has a DC / DC converter unit that converts DC voltage and a current limiting unit connected in series to the input side of this DC / DC converter unit, and that is configured to limit the inrush current at power-on to a predetermined value or less by operating this current limiting unit for a predetermined period from when the power is turned on.

[0004] However, when DC power is supplied to a device, there is little need to provide a large-capacity capacitor in the device. Therefore, in DC power supply, a current limiting means is not usually provided in the power supply device or the device connected to the power supply device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-238434 Summary of the Invention [Problem to be solved by the invention]

[0006] However, if there is a malfunction in the device connected to the power supply unit, or depending on the configuration of the device, an excessive current may flow through the power supply unit when the power supply unit is connected to the device, causing a malfunction. Therefore, it is required that the power supply unit be equipped with a means for suppressing the occurrence of a malfunction even in such cases. Furthermore, when disconnecting a device from a power supply, if current is flowing from the power supply to the device, a discharge may occur when the contacts are opened, which may result in problems such as contact welding.

[0007] The present disclosure aims to prevent excessive current from flowing through a power supply device that allows easy attachment and detachment of equipment using a connector when the power supply device is connected to an equipment, regardless of whether the equipment is faulty or its configuration. Another object of the present disclosure is to prevent problems from occurring due to current flowing when a device is removed from a power supply device. [Means for solving the problem]

[0008] The power supply device of the present disclosure includes a main power supply capable of supplying DC power, two or more connectors that can supply power from the main power supply without power conversion, and a control unit that switches the connection state between the main power supply and the connectors, the control unit switching the connection state between the main power supply and the connectors between a first state in which the main power supply and the connectors are not connected, a second state in which the main power supply and the connectors are connected via a resistor, and a third state in which the main power supply and the connectors are connected without the resistor. In this case, it is possible to prevent excessive current from flowing through the power supply device when the power supply device is connected to a device, regardless of the presence or absence of a malfunction or the configuration of the device. Here, the power supply device further includes an acquisition unit that acquires information regarding the necessity of current limiting operation by the resistor, and when the information indicates that current limiting operation by the resistor is unnecessary, the control unit switches the connection state so that the second state is maintained for a shorter time than when the information indicates that current limiting operation by the resistor is necessary. In this case, unnecessary current limiting operation is suppressed, and the time required from the start of power supply to the steady state can be shortened. The acquisition unit acquires the information from the device connected to the connector. In this case, information regarding the necessity of current limiting operation can be obtained in advance without performing a process of detecting information when power is supplied to the device. The acquisition means may also acquire a voltage of the connector in the first state before the first state is changed to the second state as a first voltage (v c1 (0)), and the voltage of the connector when a first time (Δt) has elapsed since the first state was changed to the second state is defined as a second voltage (v c1 (Δt)), and the voltage of the connector when a second time (2Δt) that is twice the first time has elapsed since the first state was changed to the second state is defined as a third voltage (v c1 When the voltage difference (Δv1) between the first voltage and the second voltage is set to (2Δt), the information is determined based on the ratio of the first voltage difference (Δv1) between the first voltage and the second voltage to the second voltage difference (Δv2) between the second voltage and the third voltage. In this case, information regarding the necessity of current-limiting operation can be obtained based on the change in the voltage of the connector when power supply to the device starts. The power supply further includes two or more first current limiting circuits and two or more first switches, each of which includes the resistor and a second switch connected in parallel to the resistor, and which has one end connected to the output of the main power supply and the other end connected to the connector via the first switch, and the control unit turns off the first switch connected to the connector in the first state in which the main power supply and the connector are not connected, turns on the first switch connected to the connector in the second state in which the main power supply and the connector are connected via the resistor, and turns off the second switch of the first current limiting circuit connected to the first switch, and turns on the first switch connected to the connector and the second switch of the first current limiting circuit connected to the first switch in the third state in which the main power supply and the connector are connected without the resistor. In this case, by switching the first and second switches on and off to control the connection state between the main power supply and the connector, it is possible to prevent excessive current from flowing through the power supply device when connecting the power supply device to the device, regardless of whether the device is faulty or its configuration. The power supply further includes two or more switch circuits, each of which includes a third switch having one end connected to the output of the main power supply and one end of the resistor and the other end connected to the connector, and a fourth switch having one end connected to the other end of the resistor and the other end connected to the connector, wherein in the first state in which the main power supply and the connector are not connected, the control unit turns off the third switch connected to the connector and also turns off the fourth switch connected to the connector; in the second state in which the main power supply and the connector are connected via the resistor, the control unit turns off the third switch connected to the connector and turns on the fourth switch connected to the connector; and in the third state in which the main power supply and the connector are connected without the resistor, the control unit turns on the third switch connected to the connector and also turns off the fourth switch connected to the connector. In this case, by switching the third and fourth switches on and off to control the connection state between the main power supply and the connector, it is possible to prevent excessive current from flowing through the power supply device when it is connected to the device, regardless of whether the device is faulty or its configuration. The power supply device further includes a second current limiting circuit and two or more fifth switches, the second current limiting circuit including the resistor and a sixth switch connected in parallel to the resistor, one end of the second current limiting circuit connected to the output of the main power supply and the other end of the sixth switch connected to the connector via the fifth switch, the control unit turning off the fifth switch connected to the connector in the first state in which the main power supply and the connector are not connected, turning on the fifth switch connected to the connector and turning off the sixth switch in the second state in which the main power supply and the connector are connected via the resistor, and turning on the fifth switch connected to the connector and turning on the sixth switch in the third state in which the main power supply and the connector are connected without the resistor. In this case, by controlling the connection state between the main power supply and the connector by switching on / off the fifth and sixth switches, it is possible to prevent excessive current from flowing through the power supply device when the power supply device is connected to an apparatus, regardless of the configuration or whether or not the apparatus is faulty. The power supply device may further include a sensor that detects the voltage or current of the connector, and the control unit, when the connection state is the second state, detects whether or not there is a short circuit between the terminals of the connector based on information from the sensor, switches the connection state from the first state to the second state, and then maintains the second state until detection of whether or not there is a short circuit between the terminals of the connector is completed, and switches the connection state to the first state when it detects that there is a short circuit between the terminals of the connector. In this case, by stopping power supply when there is a short circuit between the terminals of the connector, it is possible to prevent failures in the power supply device. The power supply device of the present disclosure further includes connector information acquisition means for acquiring connector information relating to the connection state between the connector and the device, and the control unit switches between the first state, the second state, and the third state, which are connection states between the main power supply and the connector, depending on the connection state between the connector and the device specified by the connector information. In this case, depending on the connection state between the connector and the device, it is possible to limit the power supply to the device if there is a possibility that the device will be removed. Furthermore, when the connector information indicates that the connection between the connector and the device is being switched from the third state to the second state, the control unit switches the connection state between the main power supply and the connector from the third state to the second state, thereby preventing problems caused by current flowing when the device is removed from the connector. Furthermore, the control unit switches the connection state between the main power supply and the connector from the third state to the second state, and then switches the connection state between the main power supply and the connector from the second state to the first state after a predetermined time has elapsed since the third state. In this case, after the connection state between the main power supply and the connector is switched to the second state, power supply can be stopped after the predetermined time has elapsed, regardless of the connection state between the connector and the device. The connector further includes a locking mechanism that locks the connection between the connector and the device, and the connector information acquisition means acquires information indicating the state of the locking mechanism as the connector information. The control unit sets the connection state between the main power supply and the connector to the third state when the state of the locking mechanism specified by the connector information is locked, and sets the connection state between the main power supply and the connector to the second state when the state of the locking mechanism specified by the connector information is unlocked. In this case, power supply to the device can be restricted depending on the state of the locking mechanism when there is a possibility that the device may be removed. The connector further includes a locking mechanism that locks the connection between the connector and the device, the connector information acquisition means acquires information indicating the state of the locking mechanism as the connector information, and the control unit switches the connection state between the main power supply and the connector from the third state to the second state when the state of the locking mechanism specified by the connector information transitions from a locked state to an unlocked state. In this case, it is possible to prevent malfunctions caused by current flow when removing the device from the connector in accordance with the determination of the connection state between the connector and the device based on the state of the locking mechanism. Furthermore, the connector and the device are provided with contacts that come into contact when the connector and the device are connected, separate from the power supply, and the connector information acquisition means acquires, as the connector information, information indicating whether the contacts between the connector and the device are in contact, and the control unit sets the connection state between the main power supply and the connector to the third state when the connector information indicates that the contacts between the connector and the device are in contact, and sets the connection state between the main power supply and the connector to the second state when the connector information indicates that the contacts between the connector and the device are not in contact. In this case, it is possible to limit the power supply to the device when there is a possibility that the device will be removed, depending on the contact state of the contacts. Furthermore, the connector and the device are provided with contacts that come into contact when the connector and the device are connected, separate from the power supply, and the connector information acquisition means acquires, as the connector information, information indicating whether the contacts between the connector and the device are in contact, and the control unit switches the connection state between the main power source and the connector from the third state to the second state when the connector information indicates that the contacts between the connector and the device have transitioned from a contact state to a non-contact state. In this case, it is possible to prevent problems caused by current flowing when the device is removed from the connector, depending on the determination of the connection state between the connector and the device based on the contact state at the contacts. The power supply device of the present disclosure includes a main power supply capable of supplying DC power, a connector capable of supplying power from the main power supply without power conversion, a control unit that switches a power connection state that is a connection state between the main power supply and the connector, and connector information acquisition means that acquires connector information that is information regarding a device connection state that is a connection state between the connector and a device, and the control unit switches the power connection state to one of a first state in which the main power supply and the connector are not connected, a second state in which the main power supply and the connector are connected via a resistor, or a third state in which the main power supply and the connector are connected without the resistor, depending on the device connection state identified by the connector information. In this case, it is possible to prevent problems caused by current flow when removing the device from the connector. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing the configuration of a power supply device according to a first embodiment. [Figure 2] 10 is a diagram showing the correspondence between the first to third states and the ON / OFF states of the load switch and the current limiting circuit switch. [Figure 3] 10A and 10B are diagrams showing waveforms of current and voltage in a connector at the start of power supply. [Figure 4] 10 is a table showing criteria for determining whether or not a short circuit fault occurs in an external device connected to a connector. [Figure 5] FIG. 10 is a diagram illustrating a configuration example in which an external device connected to a power supply device does not have a current limiting means. [Figure 6] FIG. 10 is a diagram illustrating a configuration example in which an external device connected to a power supply device has a current limiting means. [Figure 7] 10A and 10B are diagrams showing waveforms of current and voltage in a connector when power supply to an external device not having a current limiting circuit starts. [Figure 8] 10A and 10B are diagrams showing waveforms of current and voltage in a connector when power supply to an external device having a current limiting circuit starts. [Figure 9]10A and 10B are diagrams showing the waveforms of the current and voltage of a connector when there is residual charge in a capacitor in an external device that does not have a current limiting circuit. [Figure 10] 10A and 10B are diagrams showing the waveforms of current and voltage in a connector when there is residual charge in a capacitor in an external device having a current limiting circuit. [Figure 11] 11A and 11B are diagrams showing a method for selecting the connection state between the main power supply and the connector, where FIG. 11A is a diagram showing the selection based on the information of the power supply command, and FIG. 11B is a diagram showing the selection based on the results of short-circuit fault detection and the determination of whether or not current limiting operation is required. [Figure 12] FIG. 10 is a diagram illustrating the operation when there is no current limiting circuit in the external device and no short-circuit fault. [Figure 13] FIG. 10 is a diagram illustrating the operation when an external device has a current limiting circuit and there is no short-circuit fault. [Figure 14] FIG. 10 is a diagram illustrating an operation when a short circuit fault occurs in an external device. [Figure 15] 10A and 10B are diagrams illustrating another operation when the external device does not have a current limiting circuit and no short-circuit fault occurs. [Figure 16] 10A and 10B are diagrams illustrating another operation when the external device has a current limiting circuit and there is no short-circuit fault. [Figure 17] FIG. 10 is a diagram showing the configuration of a power supply device according to a second embodiment. [Figure 18] 10 is a diagram showing the correspondence between the first to third states and the ON / OFF states of the load switch and the current limiting circuit switch. [Figure 19] 10A and 10B are diagrams illustrating an example of an operation for determining whether a short circuit fault has been detected in an external device connected to a plurality of connectors and whether the external device has a current limiting circuit. [Figure 20] 10 is a diagram showing another example of the operation of determining whether a short-circuit fault has been detected in an external device connected to a plurality of connectors and determining whether the external device has a current-limiting circuit. FIG. [Figure 21] 10 is a diagram showing another example of the operation of determining whether a short-circuit fault has been detected in an external device connected to a plurality of connectors and determining whether the external device has a current-limiting circuit. FIG. [Figure 22]10 is a diagram showing another example of the operation of determining whether a short-circuit fault has been detected in an external device connected to a plurality of connectors and determining whether the external device has a current-limiting circuit. FIG. [Figure 23] FIG. 10 is a diagram showing an example of a configuration in which voltage detection means is shared in a power supply device according to a second embodiment. [Figure 24] 24A and 24B are diagrams showing current waveforms and voltage waveforms of a connector in response to switch control at the start of power supply in the configuration shown in FIG. 23. [Figure 25] FIG. 10 is a diagram showing the configuration of a power supply device according to a third embodiment. [Figure 26] 10 is a diagram showing the correspondence between the first to third states and the ON / OFF states of the load switch and the current limiting circuit switch. [Figure 27] 10A and 10B are diagrams illustrating an example of an operation for determining whether or not external devices connected to a plurality of connectors have current-limiting circuits. [Figure 28] 10A and 10B are diagrams illustrating an example of an operation for starting power supply to an external device. [Figure 29] 10A and 10B are diagrams illustrating another example of an operation for starting power supply to an external device. [Figure 30] 10A and 10B are diagrams illustrating another example of an operation for starting power supply to an external device. [Figure 31] 10A and 10B are diagrams illustrating the operation of the power supply device when the contacts are opened. [Figure 32] 10A and 10B are diagrams illustrating the relationship between the lock state of a locking mechanism provided in a connector and control of a power supply device. [Figure 33] 33A and 33B show examples of the configuration of a socket and a plug in specific example 2, in which FIG. 33A shows the socket and the plug fully attached, FIG. 33B shows the non-powered contacts disconnected, and FIG. 33C shows the plug removed from the socket. [Figure 34] 10A and 10B are diagrams illustrating the relationship between the connection state between the connector and an external device and the control of the power supply device. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. A power supply device according to the present disclosure includes a plurality of connectors, and devices are connected to each of the plurality of connectors to supply power. Hereinafter, devices that are provided separately from the power supply device and connected to the connectors will be referred to as external devices. Because the external devices are connected via connectors, they are easily attached and detached. The power supply device includes a current limiting circuit that limits the current supplied to the external devices. Hereinafter, power supply devices according to first to third embodiments will be presented and described according to the configuration of this current limiting circuit.

[0011] First embodiment <Power supply configuration> 1 is a diagram showing the configuration of a power supply device according to a first embodiment. The power supply device 100 includes a main power supply 110, a plurality of connectors 120, a plurality of load switches 130, a plurality of current limiting circuits 140, and a control unit 150. The connectors 120, the load switches 130, and the current limiting circuits 140 form individual corresponding pairs, and each pair of the connectors 120, the load switches 130, and the current limiting circuits 140 is connected in parallel to the main power supply 110.

[0012] The main power supply 110 is a DC power supply, and in each of the above pairs, supplies DC power to the connector 120 via the load switch 130. No circuit for power conversion is provided between the main power supply 110 and the connector 120. The main power supply 110 may receive power from an external power supply, convert the power, and output it to the connector 120. Examples of external power sources that supply power to the main power supply 110 include a system power supply, a solar cell, and a storage battery. A capacitor 111 is provided at the output of the main power supply 110.

[0013] An external device as a load can be detachably connected to each of the multiple connectors 120. When an external device is connected to the connector 120, the power supply device 100 can supply power to the external device via the connector 120. Each of the multiple load switches 130 switches between supplying (ON) and cutting off (OFF) power from the main power supply 110 to the connector 120 corresponding to each load switch 130. The load switch 130 in the first embodiment is an example of a first switch.

[0014] One end of each of the multiple current limiting circuits 140 is connected to a capacitor 111 provided at the output of the main power supply 110. The other end of the current limiting circuit 140 is connected to a connector 120. The current limiting circuit 140 includes a resistor 141 and a switch 142 provided in parallel with the resistor 141. Hereinafter, the switch 142 provided in the current limiting circuit 140 may be referred to as a current limiting circuit switch 142 to distinguish it from the load switch 130. The current limiting circuit 140 in the first embodiment is an example of a first current limiting circuit. The switch 142 is also an example of a second switch.

[0015] The control unit 150 controls each of the multiple load switches 130 and the current limiting circuits 140. Specifically, the control unit 150 controls the electrical connection state between the main power supply 110 and each connector 120 by switching the load switches 130 and the current limiting circuit switches 142 ON / OFF. The control unit 150 controls the connection state between the main power supply 110 and each connector 120 to one of three states, a first state, a second state, and a third state. The control unit 150 is realized, for example, by a memory that stores a program and a processor that executes the program stored in the memory.

[0016] 2 is a diagram showing the correspondence between the first to third states and the ON / OFF states of the load switch 130 and the current limiting circuit switch 142. Referring to FIG. 2, the first state is a state (shutoff state) in which the main power supply 110 and the connector 120 are not connected. In the first state, the load switch 130 is OFF. Because the load switch 130 is OFF and the main power supply 110 and the connector 120 are disconnected, the state of the current limiting circuit switch 142 cannot be specified.

[0017] The second state is a state (current limiting state) in which the main power supply 110 and the connector 120 are connected via the resistor 141. In the second state, the load switch 130 is ON, and the current limiting circuit switch 142 is OFF.

[0018] The third state is a state (direct connection state) in which the main power supply 110 and the connector 120 are connected without the resistor 141. In the third state, the load switch 130 is ON, and the current limiting circuit switch 142 is ON.

[0019] <Current and voltage waveforms of connector 120 at the start of power supply> Fig. 3 is a diagram showing the waveforms of the current and voltage of the connector 120 when power supply starts. Fig. 3 shows the state changes at the start of power supply for one set of connector 120, load switch 130, and current limiting circuit 140. Specifically, the diagram shows the state changes of the current limiting circuit switch 142 and the load switch 130, and the change in the connection state between the main power supply 110 and the connector 120 (denoted as "current limiting circuit of the power supply device" in the diagram). Also shown are the current and voltage waveforms when a short-circuit fault occurs in the external device connected to the connector 120, and the current and voltage waveforms when the external device connected to the connector 120 is normal.

[0020] 3, in the initial state, the current limiting circuit switch 142 and the load switch 130 of the current limiting circuit 140 are OFF. Because both the current limiting circuit switch 142 and the load switch 130 are OFF, the connection state between the main power supply 110 and the connector 120 in the initial state is the first state (shutoff). At this time, the current in the connector 120 is 0 [A] (amperes) and the voltage is 0 [V] (volts).

[0021] When power supply starts, the control unit 150 of the power supply device 100 first turns on the load switch 130 and then turns on the current limiting circuit switch 142. The timing when the load switch 130 turns on is defined as t1, and the timing when the current limiting circuit switch 142 turns on is defined as t2. In this manner, from t1 onwards, the current limiting circuit switch 142 is OFF and the load switch 130 is ON, so the connection state between the main power supply 110 and the connector 120 is in the second state (current limiting). Furthermore, from t2 onwards, the current limiting circuit switch 142 and the load switch 130 are both ON, so the connection state between the main power supply 110 and the connector 120 is in the third state (direct connection).

[0022] If the external device connected to connector 120 is normal, the current value of connector 120 increases when load switch 130 is turned ON at time t1, and then decays exponentially. Then, when current-limiting circuit switch 142 is turned ON at time t2, the current value increases slightly, then returns to 0 [A], and then enters a steady state.

[0023] When the load switch 130 is turned ON at t1, the voltage at the connector 120 gradually increases while charging the capacitor of the external device. When the current-limiting circuit switch 142 is turned ON at t2, the voltage at the connector 120 matches the output voltage V0 of the main power supply 110 and enters a steady state.

[0024] If there is a short circuit in the external device connected to the connector 120, the current in the connector 120 will jump up and remain at that state when the load switch 130 is turned on at time t1. Therefore, the current that jumped up at time t1 will not decay.

[0025] Also, even when the load switch 130 turns ON at t1, the voltage of the connector 120 does not increase. When a short - circuit fault is detected in an external device, the main power supply 110 and the connector 120 are not directly connected. Therefore, the current - limiting circuit switch 142 does not turn ON. For this reason, in FIG. 3, after t2, the waveforms of the current and voltage when there is a short - circuit fault in the external device are not shown.

[0026] <Detection of short - circuit fault> As described with reference to FIG. 3, the current waveform and voltage waveform at the connector 120 are significantly different between the case where the external device connected to the connector 120 is normal and the case where there is a short - circuit fault in the external device. Therefore, based on this difference in waveforms, it is possible to detect whether there is a short - circuit fault in the external device connected to the connector 120.

[0027] FIG. 4 is a chart showing the criteria for determining whether there is a short - circuit fault in the external device connected to the connector 120. FIG. 4 shows the correspondence between the processes that can be used to determine whether there is a short - circuit fault in the external device and the criteria for determining whether there is a short - circuit fault in the external device.

[0028] As one process, the voltage value v of the connector 120 after a time T has elapsed since the load switch 130 turned ON at t1 th is detected. Here, the time T c1 is a time that specifies a point between t1 and t2 and is a determination threshold value. Therefore, T th <t2 - t1. Details of the time T th will be described later. In the case of this process, if v th ≧v c1 , it is determined that the external device connected to the connector 120 is normal. Also, if v th <v c1 <v th , it is determined that the external device connected to the connector 120 is abnormal (there is a short - circuit fault). Here, v this a threshold voltage value that is set in advance as a criterion for determining whether or not a short circuit fault occurs in the external device connected to the connector 120.

[0029] As another process, the voltage value v of the connector 120 c1 At regular intervals, the load switch 130 is turned on (t1) and the elapsed time t is measured. th DeV c1 ≧v th If 0≦t≦T, the external device connected to the connector 120 is determined to be normal. th Always v c1 <v th If so, it is determined that the external device connected to the connector 120 is abnormal (has a short circuit).

[0030] As another process, the load switch 130 is turned on (t1) and then the time T th The current value i of the connector 120 after c1 In this process, i c1 ≦i th If so, it is determined that the external device connected to the connector 120 is normal. c1 >i th If so, it is determined that the external device connected to the connector 120 is abnormal (has a short circuit). th is a threshold value of the current value that is set in advance as a criterion for determining whether or not a short circuit fault occurs in the external device connected to the connector 120.

[0031] As another process, the current value i of the connector 120 c1 At regular intervals, the load switch 130 is turned on (t1) and the elapsed time t is measured. th In i c1 ≦i th If 0≦t≦T, the external device connected to the connector 120 is determined to be normal. th Always i c1 >i thIf so, it is determined that the external device connected to the connector 120 is abnormal (has a short circuit).

[0032] <Determining whether current limiting operation is necessary> Next, a determination as to whether or not current limiting operation is required in the power supply device 100 will be explained. A variety of external devices are easily connected to the power supply device 100 via the connector 120. External devices connected to the connector 120 include those that have current limiting means themselves and those that do not. If the external device has current limiting means, current limiting operation in the power supply device 100 is unnecessary, and it is desirable to shorten the time for current limiting operation and immediately connect the main power supply 110 and the connector 120 directly. Even in the case of an external device that does not have current limiting means, if it does not have a large-capacity capacitor, current limiting operation in the power supply device 100 is unnecessary, and it is desirable to shorten the time for current limiting operation and immediately connect the main power supply 110 and the connector 120 directly. A method for determining whether or not current limiting operation is required in the power supply device 100 will be explained below.

[0033] Fig. 5 is a diagram showing a configuration example in which an external device connected to the power supply device 100 does not have a current limiting means. Fig. 6 is a diagram showing a configuration example in which an external device connected to the power supply device 100 has a current limiting means.

[0034] 5 includes a circuit 210, and is connected to the connector 120 of the power supply device 100 via a connector 201. A capacitor 211 is provided at the input of the circuit 210.

[0035] 6 includes a circuit 210 and a current-limiting circuit 220, and is connected to the connector 120 of the power supply device 100 via a connector 201. A capacitor 211 is provided at the input of the circuit 210. The current-limiting circuit 220 includes a resistor 221 and a switch 222 provided in parallel with the resistor 221. The current-limiting circuit 220 is an example of a current-limiting means of the external device 200.

[0036] <Detection of the current limiting circuit of the external device 200 based on the current and voltage waveforms of the connector 120> FIG. 7 is a diagram showing the waveforms of the current and voltage of the connector 120 when power supply to the external device 200 that does not have a current limiting circuit 220 starts. FIG. 8 is a diagram showing the waveforms of the current and voltage of the connector 120 when power supply to the external device 200 that has a current limiting circuit 220 starts. FIGS. 7 and 8 show the state changes at the start of power supply for one combination of the connector 120, the load switch 130, and the current limiting circuit 140. Specifically, the state changes of the current limiting circuit switch 142 and the load switch 130 and the change in the connection state between the main power supply 110 and the connector 120 (denoted as "current limiting circuit of the power supply device" in the figure) are shown. FIGS. 7 and 8 also show the waveforms of the current and voltage when the external device 200 is connected to the connector 120 and power supply starts.

[0037] 8 further shows a change in the state of the switch 222 of the current limiting circuit 220 in the external device 200. The switch 222 is initially OFF, and turns ON after a certain time has elapsed when power supply to the external device 200 starts. The timing at which the switch 222 turns ON is designated as t3.

[0038] The current and voltage waveforms shown in Fig. 7 are similar to those shown in Fig. 3 when the external device 200 is normal. Therefore, the current in the connector 120 increases in value at t1 and then decays exponentially. Then, after a slight increase in value at t2, the current returns to 0 [A] and enters a steady state. Furthermore, the voltage in the connector 120 gradually increases after t1 and coincides with the output voltage V0 of the main power supply 110 at t2, entering a steady state.

[0039] 8, when load switch 130 is turned ON at t1, the current value of connector 120 jumps up and then decays exponentially. When current-limiting circuit switch 142 is turned ON at t2, the current value jumps up again and then decays exponentially. When switch 222 is turned ON at t3, the current value jumps up slightly, then returns to 0 [A] and enters a steady state.

[0040] When the external device 200 has the current limiting circuit 220, in the current-limiting state, the capacitor 211 is charged via the resistor 141 of the current limiting circuit 140 in the power supply device 100 and the resistor 221 of the current limiting circuit 220 in the external device 200. Therefore, the voltage of the connector 120 is divided by the resistor 141 of the current limiting circuit 140 and the resistor 221 of the current limiting circuit 220. For this reason, the behavior of the voltage of the connector 120 differs from the behavior shown in FIG. 7.

[0041] 8, when the load switch 130 is turned ON at t1, the voltage value of the connector 120 jumps up, and then gradually increases. Then, when the current limiting circuit switch 142 is turned ON at t2, the voltage value of the connector 120 matches the output voltage V0 of the main power supply 110, and enters a steady state. The value of the voltage value that jumped up at t1 is a value smaller than the output voltage V0 of the main power supply 110, and is determined by the resistance value of the resistor 141 of the current limiting circuit 140 in the power supply device 100 and the resistance value of the resistor 221 of the current limiting circuit 220 in the external device 200.

[0042] 8, the voltage of capacitor 211 of external device 200 is indicated by a dashed line. When load switch 130 of power supply device 100 is turned ON at t1, charging of capacitor 211 begins and the voltage value gradually increases. When current limiting circuit switch 142 is turned ON at t2, the voltage of connector 120 in power supply device 100 matches output voltage V0 of main power supply 110, but charging of capacitor 211 continues via current limiting operation by current limiting circuit 220 of external device 200. Therefore, the voltage value of capacitor 211 gradually increases. Then, when switch 222 of current limiting circuit 220 is turned ON at t3, the voltage of capacitor 211 matches output voltage V0 of main power supply 110.

[0043] 7 and 8, Δv1 and Δv2 are calculated from the voltage of the connector 120 in the section from t1 to t2. Here, Δv1 is the connector voltage v immediately before the load switch 130 is turned ON. c1 (0), and the connector voltage v after the time Δt has elapsed since the load switch 130 was turned on. c1(Δt). Therefore, Δv1=v c1 (Δt)-v c1 (0).

[0044] Δv2 is the voltage v of the connector 120 (hereinafter referred to as the "connector voltage") after the time Δt has elapsed since the load switch 130 was turned on. c1 (Δt), and the connector voltage v after the time 2Δt has elapsed since the load switch 130 was turned on. c1 (2Δt). Therefore, Δv2=v c1 (2Δt)-v c1 (Δt).

[0045] Using these Δv1 and Δv2, the presence or absence of the current limiting circuit 220 in the external device 200 is determined by the following equation (Equation 1).

number

[0046] In the above equation (Equation 1), Δt is the interval between detection times of the connector voltage. th is the decision threshold. T th can be set appropriately, but as an example, the lower limit of the capacitance of the capacitor 211 of the external device 200 (hereinafter referred to as "capacitor capacitance") is set to C th , when the resistance value of the resistor 141 of the current limiting circuit 140 in the power supply device 100 is R, for example, T th =C th ·R. Here, the current limiting operation by the current limiting circuit 140 in the power supply device 100 is required when the capacitor capacity of the external device 200 is relatively large. Here, the lower limit (threshold value) of the capacitor capacity at which the current limiting operation by the current limiting circuit 140 is required is set to C th It states that:

[0047] If the above formula (Equation 1) is satisfied, it is determined that the external device 200 does not have a current limiting circuit 220 and has a large capacitor capacity. In this case, current limiting operation by the current limiting circuit 140 of the power supply device 100 is necessary. On the other hand, if the above formula (Equation 1) is not satisfied, it is determined that the external device 200 has a current limiting circuit 220 or has a small capacitor capacity. In this case, current limiting operation by the current limiting circuit 140 of the power supply device 100 is not necessary.

[0048] In addition, the connector voltage v c1 When detecting the voltage to determine whether or not a current-limiting operation is required for the external device 200, it is preferable to detect the voltage at a position between the load switch 130 and the connector 120. This position allows detection of the voltage (connector voltage) of the external device 200 connected to the connector 120 both when the load switch 130 is ON and when it is OFF.

[0049] In the external device 200, for example, due to residual charge in the internal capacitor 211, the connector voltage may be greater than 0 [V] even when the load switch 130 of the power supply device 100 is OFF. In such a case, the connector voltage v c1 If (0) is not known, the value of Δv1 described above may be incorrect, which may lead to an incorrect determination of whether or not a current limiting operation is required for the external device 200. The position between the load switch 130 and the connector 120 described above allows the connector voltage (voltage of the external device 200) to be detected even when the load switch 130 is OFF. Therefore, the connector voltage v c1 Even if (0) is other than 0 [V], it is possible to appropriately determine whether or not the current limiting operation of the external device 200 is necessary.

[0050] <Current and voltage waveforms when there is residual charge in the capacitor 211 of the external device 200> Next, we will explain the waveforms of the current and voltage at the connector 120 when there is residual charge in the capacitor 211 of the external device 200. As described above, when there is residual charge in the capacitor 211 of the external device 200, the connector voltage may be greater than 0 [V] even if the load switch 130 of the power supply device 100 is OFF.

[0051] FIG. 9 shows the waveforms of the current and voltage in the connector 120 when the capacitor 211 of the external device 200 does not have a current limiting circuit 220 and there is a residual charge. FIG. 10 shows the waveforms of the current and voltage in the connector 120 when the capacitor 211 of the external device 200 has a current limiting circuit 220 and there is a residual charge. FIGS. 9 and 10 show the state changes of a single combination of the connector 120, the load switch 130, and the current limiting circuit 140 at the start of power supply. Specifically, the state changes of the current limiting circuit switch 142 and the load switch 130 and the connection state between the main power supply 110 and the connector 120 (denoted as "current limiting circuit of the power supply device" in the figure) are shown. Furthermore, FIG. 10 shows the state changes of the switch 222 of the current limiting circuit 220 in the external device 200. FIGS. 9 and 10 also show the waveforms of the current and voltage when the external device 200 is connected to the connector 120 and power supply starts.

[0052] 9 and 10, there is residual charge in the capacitor 211 of the external device 200, so the connector voltage is greater than 0 [V] even in the section of the first state (shutoff) where the load switch 130 is OFF. Other changes in the waveform are the same as those described with reference to FIGS. 7 and 8.

[0053] <Derivation of Equation (1)> Here, an example of a method for deriving the equation (Equation 1) used to determine the presence or absence of the current limiting circuit 220 in the external device 200 will be described. The step response of an RC circuit is expressed by the following equation (Equation 2).

number

[0054] Substituting Δv2 / Δv1 into the above equation (Equation 2) and rearranging it yields the following equation (Equation 3).

number

[0055] Next, a relational expression (Equation 1) is derived to determine whether the conditions "the external device 200 does not have a current limiting circuit 220" and "the capacitance of the input capacitor 211 of the external device 200 is large" are satisfied. Based on these conditions, the time constant T=R·C in the expression satisfies T≧T th = R·C th In addition, C th is the lower limit value of the capacitance of the capacitor of the external device 200 that requires the current limiting circuit 220. R is the resistance value of the resistor 221 of the current limiting circuit 220 of the external device 200. Therefore, T≧T th Substituting the above, we obtain the inequality (Equation 1).

[0056] <Method for controlling the connection state between the main power supply 110 and the connector 120> Next, we will explain the method for controlling the connection state (first to third states) between the main power supply 110 and the connector 120 in the power supply device 100. The control unit 150 of the power supply device 100 selects which state the connection state between the main power supply 110 and the connector 120 should be, from the first state (shutoff), the second state (current limiting), or the third state (direct connection), based on the following information: (a) Power supply command: Yes / No (b) Short circuit fault detection: Unknown / No short circuit fault / Short circuit fault (c) Current-limiting operation required: unknown / necessary / no

[0057] Here, the "power supply command" is a command as to whether or not to supply power to the connector 120. The "short circuit fault detection" is information indicating the result of the detection of a short circuit fault in the external device 200 connected to the connector 120. The "necessity of current limiting operation" is information indicating the result of the determination by the current limiting circuit 140 as to whether or not current limiting operation is necessary. Note that "unknown" in the information (b) and (c) means that the determination process has not yet been performed or is currently being performed. The control unit 150 is an example of an acquisition means for acquiring this information.

[0058] FIG. 11 is a diagram showing a method for selecting the connection state between the main power supply 110 and the connector 120. FIG. 11(A) shows a diagram illustrating selection based on information of a power supply command. FIG. 11(B) shows a diagram illustrating selection based on the results of short-circuit fault detection and the determination of whether current-limiting operation is required. For example, if there is no power supply command, the first state (shutdown) is selected (see FIG. 11(A)). If there is a power supply command, one of the first state (shutdown), the second state (current-limiting), and the third state (direct connection) is selected according to the combination of the determination result of short-circuit fault detection and the determination result of whether current-limiting operation is required (see FIG. 11(B)). Note that in FIG. 11(B), the item "Current-limiting operation required" has sub-items "Current-limiting operation incomplete" and "Current-limiting operation completed." Here, the control unit 150 determines that "current-limiting operation is completed" if a predetermined condition is satisfied in the second state, and determines that "current-limiting operation is incomplete" if it is not satisfied. The third state is defined as “current limiting operation completed,” and the first state is defined as “current limiting operation not completed.” Examples of the predetermined conditions include “duration of the second state ≧ predetermined value,” and “connector voltage ≧ threshold value.”

[0059] Next, the control unit 150 of the power supply device 100 controls the ON / OFF states of the load switch 130 and the current limiting circuit switch 142 in accordance with the correspondence shown in Fig. 2 so that the main power supply 110 and the connector 120 are in the selected connection state (first state to third state). By controlling the load switch 130 and the current limiting circuit switch 142, the connection state between the main power supply 110 and the connector 120 becomes the connection state determined as described above.

[0060] <Determining the Connection State Between the Main Power Supply 110 and the Connector 120> 12 to 16, the process of determining the connection state between the main power supply 110 and the connector 120 by the control unit 150 will be described. In the following description, whether or not current limiting operation by the current limiting circuit 140 is necessary will be explained by replacing it with the presence or absence of the current limiting circuit 220 in the external device 200. Therefore, "Current limiting operation necessary: ​​necessary" in FIG. 11(B) corresponds to the absence of the current limiting circuit 220 in the external device 200. Also, "Current limiting operation necessary: ​​no" in FIG. 11(B) corresponds to the presence of the current limiting circuit 220 in the external device 200. Note that even in a configuration in which current limiting operation by the current limiting circuit 140 of the power supply device 100 is not necessary, such as when the external device 200 is not provided with a large-capacity capacitor, the description will be given assuming that the external device 200 has the current limiting circuit 220.

[0061] Here, in addition to distinguishing between cases depending on the combination of the presence or absence of the current limiting circuit 220 and the presence or absence of a short-circuit fault in the external device 200, control when the presence or absence of the current limiting circuit 220 in the external device 200 is known in advance will also be described. 12 to 16 respectively show changes in the connection state between the main power supply 110 and the connector 120 (denoted as "current limiting circuit of the power supply device" in the figures), state changes of the current limiting circuit switch 142 and the load switch 130, current waveforms and voltage waveforms, the determination result of short-circuit fault detection, and the determination result of the presence or absence of the current limiting circuit 220 in the external device 200. Furthermore, with regard to the connection state between the main power supply 110 and the connector 120, the first state (shutdown) is denoted as "1 (shutdown)," the second state (current limiting) as "2 (current limiting)," and the third state (direct connection) as "3 (direct connection)."

[0062] 12 is a diagram showing the operation when the external device 200 does not have a current limiting circuit 220 and there is no short-circuit fault. In FIG. 12, in the first state (shutoff) in which the load switch 130 and the current limiting circuit switch 142 are OFF, the current in the connector 120 is 0 [A] and the voltage is 0 [V]. The determination of short-circuit fault detection and the presence or absence of the current limiting circuit 220 in the external device 200 have not yet been performed. Therefore, the presence or absence of the current limiting circuit 220 is unknown.

[0063] In the second state (current limiting) in which the load switch 130 is turned on, the current and voltage of the connector 120 exhibit the waveform pattern described with reference to FIG. 7. Then, the process of determining whether a short-circuit fault is detected and whether a current-limiting circuit 220 is present is started. In FIG. 12, in the second state (current limiting), the current jumps up once and then attenuates, and the voltage gradually rises, so it is determined that there is no short-circuit fault in the external device 200. Furthermore, from the way the voltage rises, it is determined that the external device 200 does not have a current-limiting circuit 220.

[0064] 12, the external device 200 does not have the current limiting circuit 220, so a current limiting operation is required in the power supply device 100. Therefore, even after the determination process is completed, the current limiting circuit switch 142 remains OFF and the second state (current limiting) continues until the predetermined condition described with reference to FIG. 11(B) is met. After this, when the predetermined condition is met, the current limiting circuit switch 142 turns ON, and the connection state between the main power supply 110 and the connector 120 becomes the third state (direct connection).

[0065] Fig. 13 is a diagram showing the operation when the external device 200 has the current limiting circuit 220 and there is no short-circuit fault. In Fig. 13, in the first state (shutoff) in which the load switch 130 and the current limiting circuit switch 142 are OFF, the current in the connector 120 is 0 [A] and the voltage is 0 [V]. The determination of short-circuit fault detection and the presence or absence of the current limiting circuit 220 in the external device 200 have not yet been performed. Therefore, the presence or absence of the current limiting circuit 220 is unknown.

[0066] In the second state (current limiting) in which the load switch 130 is turned on, the current and voltage of the connector 120 exhibit the waveform pattern described with reference to FIG. 8. Then, the process of determining whether a short-circuit fault is detected and whether a current-limiting circuit 220 is present is started. In FIG. 13, in the second state (current limiting), the current jumps up once and then attenuates, and the voltage gradually rises, so it is determined that there is no short-circuit fault in the external device 200. Furthermore, from the way the voltage rises, it is determined that the external device 200 has a current-limiting circuit 220.

[0067] 13, the external device 200 has the current limiting circuit 220, so that the current limiting operation of the power supply device 100 is unnecessary. Therefore, immediately after the determination process is completed, the current limiting circuit switch 142 is turned ON, and the connection state between the main power supply 110 and the connector 120 becomes the third state (direct connection). In this way, when the external device 200 has the current limiting circuit 220 (FIG. 13), the period of the second state (current limiting) can be shortened compared to when the external device 200 does not have the current limiting circuit 220 (FIG. 12).

[0068] Fig. 14 is a diagram showing the operation when a short-circuit fault occurs in the external device 200. In Fig. 14, in the first state (shutoff) in which the load switch 130 and the current limiting circuit switch 142 are OFF, the current in the connector 120 is 0 [A] and the voltage is 0 [V]. The determination of short-circuit fault detection and the presence or absence of the current limiting circuit 220 in the external device 200 have not yet been performed. Therefore, the presence or absence of the current limiting circuit 220 is unknown.

[0069] In the second state (current limiting) in which the load switch 130 is turned on, the current and voltage of the connector 120 exhibit waveform patterns similar to those of the waveforms when there is a short circuit in the external device 200 described with reference to FIG. 3. Then, the process of determining whether or not there is a short circuit and the process of determining whether or not there is a current limiting circuit 220 are started. In FIG. 14, in the second state (current limiting), the current remains high and the voltage remains at 0 [V]. Therefore, it is determined that there is a short circuit in the external device 200.

[0070] Since it is determined that there is a short-circuit fault in the external device 200, the load switch 130 is immediately turned OFF. As a result, the connection state between the main power supply 110 and the connector 120 returns to the first state (shut-off). In addition, the process of determining whether or not the current limiting circuit 220 is present also ends, and the presence or absence of the current limiting circuit 220 becomes unknown.

[0071] Fig. 15 is a diagram showing another operation in the case where the external device 200 does not have the current limiting circuit 220 and there is no short-circuit fault. Also, in Fig. 15, it is assumed that the control unit 150 of the power supply device 100 has acquired information indicating that the external device 200 does not have the current limiting circuit 220. An example of such a case is when power is supplied for the second or subsequent time after a certain external device 200 is connected, and the determination result from the previous power supply is stored in the memory of the control unit 150. Another example is when the power supply device 100 has a configuration capable of communicating with the external device 200, and the control unit 150 receives information from the external device 200 about the presence or absence of the current limiting circuit 220.

[0072] 15, in the first state (shutoff) in which the load switch 130 and the current limiting circuit switch 142 are OFF, the current in the connector 120 is 0 [A] and the voltage is 0 [V]. A determination as to whether a short-circuit fault has been detected has not yet been made. On the other hand, based on the acquired information, it has already been determined that the external device 200 does not have a current limiting circuit 220.

[0073] In the second state (current limiting) in which the load switch 130 is turned on, the current and voltage of the connector 120 exhibit the waveform pattern described with reference to Fig. 7. Then, the process of determining whether or not a short circuit has occurred is initiated. In Fig. 15, in the second state (current limiting), the current jumps up once and then attenuates, and the voltage gradually increases, so it is determined that no short circuit has occurred in the external device 200.

[0074] 15, the external device 200 does not have a current limiting circuit 220, so a current limiting operation is required in the power supply device 100. Therefore, the current limiting circuit switch 142 is maintained in the OFF state and the second state (current limiting) continues until the predetermined condition described with reference to FIG. 11(B) is met. After this, when the predetermined condition is met, the current limiting circuit switch 142 is turned ON, and the connection state between the main power supply 110 and the connector 120 becomes the third state (direct connection).

[0075] Fig. 16 is a diagram showing another operation when the external device 200 has the current limiting circuit 220 and there is no short-circuit fault. Also, in Fig. 16, it is assumed that the control unit 150 of the power supply device 100 has acquired information indicating that the external device 200 has the current limiting circuit 220. An example of such a case is when power is supplied for the second or subsequent time since the external device 200 was connected, and the determination result from the previous power supply is stored in the memory of the control unit 150. Another example is when the power supply device 100 has a configuration capable of communicating with the external device 200, and the control unit 150 receives information from the external device 200 about the presence or absence of the current limiting circuit 220.

[0076] 16, in the first state (shutoff) in which the load switch 130 and the current limiting circuit switch 142 are OFF, the current in the connector 120 is 0 [A] and the voltage is 0 [V]. A determination as to whether a short-circuit fault has been detected has not yet been made. On the other hand, based on the acquired information, it has already been determined that the external device 200 has a current limiting circuit 220.

[0077] In the second state (current limiting) in which the load switch 130 is turned on, the current and voltage of the connector 120 exhibit the waveform pattern described with reference to Fig. 7. Then, the process of determining whether or not a short circuit has occurred is initiated. In Fig. 16, in the second state (current limiting), the current jumps up once and then attenuates, and the voltage gradually increases, so it is determined that no short circuit has occurred in the external device 200.

[0078] In the example of FIG. 16, the external device 200 includes the current limiting circuit 220, eliminating the need for a current limiting operation in the power supply device 100. Therefore, immediately after the determination process for short-circuit fault detection is completed, the current limiting circuit switch 142 is turned ON, and the connection state between the main power supply 110 and the connector 120 becomes the third state (direct connection). In this manner, when the external device 200 includes the current limiting circuit 220 (FIG. 16), the period of the second state (current limiting) can be shortened compared to when the external device 200 does not include the current limiting circuit 220 (FIG. 12). Furthermore, when the power supply device 100 has acquired information indicating that the external device 200 includes the current limiting circuit 220 (FIG. 16), the period of the second state (current limiting) can be further shortened compared to when the presence or absence of the current limiting circuit 220 is determined (FIG. 13).

[0079] Second embodiment <Power supply configuration> 17 is a diagram showing the configuration of a power supply device according to the second embodiment. The power supply device 100 includes a main power supply 110, a plurality of connectors 120, a plurality of load switches 130, a control unit 150, a resistor 161, and a plurality of switches 162. The connectors 120, the load switches 130, and the switches 162 form individual corresponding pairs, and each pair of the connectors 120, the load switches 130, and the switches 162 is connected in parallel to the main power supply 110.

[0080] The main power supply 110, connector 120, load switch 130, and control unit 150 are the same as those in the first embodiment described with reference to Fig. 1. Therefore, the same reference numerals are used for these components, and their description will be omitted. Furthermore, in the configuration and operation of the power supply device 100 in the second embodiment, descriptions of the same components as those in the power supply device 100 in the first embodiment, such as the determination procedure related to the external device 200 and the procedure for controlling the connection state between the main power supply 110 and connector 120, will be omitted as appropriate. The load switch 130 in the second embodiment is an example of a third switch.

[0081] In the configuration shown in FIG. 17, one end of a resistor 161 is connected to the main power supply 110, and the other end is connected to each of a plurality of switches 162. Each of the plurality of switches 162 individually connects the resistor 161 to each of the connectors 120. In the power supply device 100 shown in FIG. 17, a current limiting circuit for each connector 120 is configured by one resistor 161, a plurality of switches 162 for each connector 120, and a load switch 130 for each connector 120. Therefore, in the power supply device 100 shown in FIG. 17, the current limiting circuits corresponding to each connector 120 share one resistor 161. Hereinafter, the switch 162 may be referred to as a current limiting circuit switch 162 to distinguish it from the load switch 130. The switch 162 is an example of a fourth switch.

[0082] FIG. 18 is a diagram showing the correspondence between the first to third states and the ON / OFF states of the load switch 130 and the current limiting circuit switch 162. Referring to FIG. 18, in the first state (shutdown), the load switch 130 is OFF and the current limiting circuit switch 162 is OFF. In the second state (current limiting), the load switch 130 is OFF and the current limiting circuit switch 162 is ON. In the third state (direct connection), the load switch 130 is ON and the current limiting circuit switch 162 is OFF. Note that in the second state (current limiting), only one of the multiple current limiting circuit switches 162 may be ON. In other words, it may be prohibited to turn two or more current limiting circuit switches 162 ON at the same time.

[0083] <Determining the Connection State Between the Main Power Supply 110 and the Connector 120> 19 to 22, the process of determining the connection state between the main power supply 110 and the connector 120 by the control unit 150 will be described. In the examples shown in FIGS. 19 to 22, except for the specific case shown in FIG. 21, power supply is started sequentially to each of the multiple connectors 120 when power supply is started. To indicate the order in which power supply starts, FIGS. 19 to 22 compare three sets of connectors 120, load switches 130, and current-limiting circuit switches 162. Each set is distinguished by adding suffixes 1, 2, and 3 to each component. For example, they are described as current-limiting circuit switch 162-1, load switch 130-1, and connector 120-1. The suffixes 1, 2, and 3 identify each set. For example, a set including current-limiting circuit switch 162-1, load switch 130-1, and connector 120-1 is referred to as set 1, and a set including current-limiting circuit switch 162-2, load switch 130-2, and connector 120-2 is referred to as set 2. When it is not necessary to distinguish between sets of components, they will simply be described as the current-limiting circuit switch 162, the load switch 130, the connector 120, and so on.

[0084] 19 to 22, in addition to distinguishing between cases depending on the combination of the presence or absence of the current limiting circuit 220 and the presence or absence of a short-circuit fault in the external device 200, control when the presence or absence of the current limiting circuit 220 in the external device 200 is known in advance will also be described. FIGS. 19 to 22 respectively show state changes of the current limiting circuit switches 162-1, 162-2, and 162-3 and the load switches 130-1, 130-2, and 130-3. Also shown are current and voltage waveforms in the connectors 120-1, 120-2, and 120-3, and changes in the connection states (first state (shutoff), second state (current limiting), and third state (direct connection)) between the main power supply 110 and the connectors 120-1, 120-2, and 120-3. Also shown are the results of short-circuit fault detection in the connectors 120-1, 120-2, and 120-3, and the results of determination of the presence or absence of the current limiting circuit 220 in the external device 200. 19 to 22, with regard to the connection state between the main power supply 110 and the connector 120, the first state (shut off) is indicated as "1 (shut off)", the second state (current limiting) is indicated as "2 (current limiting)", and the third state (direct connection) is indicated as "3 (direct connection)".

[0085] Fig. 19 is a diagram showing an example of an operation for determining whether a short circuit fault has been detected in the external devices 200 connected to a plurality of connectors 120 and determining whether the external devices 200 have current-limiting circuits 220. In the example of operation shown in Fig. 19, determination and control for each group are performed in sequence for each group. Here, the operation for each group will be described first, and then the relationship between the operations of each group will be described.

[0086] First, the first set will be described. In FIG. 19, in the first state (shutdown) when the load switch 130-1 and the current limiting circuit switch 162-1 are OFF, the current in the connector 120-1 is 0 [A] and the voltage is 0 [V]. In the second state (current limiting) when the current limiting circuit switch 162-1 is ON, the current and voltage in the connector 120 exhibit the waveform pattern described with reference to FIG. 7. Therefore, it is determined that the external device 200 connected to the connector 120-1 does not have a short-circuit fault and does not have a current limiting circuit 220. Since the external device 200 does not have a current limiting circuit 220, a current limiting operation is required in the power supply device 100. Therefore, after the ON state of the current limiting circuit switch 162-1 is maintained until the predetermined condition described with reference to FIG. 11(B) is satisfied, the load switch 130-1 is turned ON, the current limiting circuit switch 162-1 is turned OFF, and the connection state between the main power supply 110 and the connector 120 becomes the third state (direct connection).

[0087] Next, the second set will be described. In Fig. 19, in the first state (shutdown) in which the load switch 130-2 and the current limiting circuit switch 162-2 are OFF, the current in the connector 120-2 is 0 [A] and the voltage is 0 [V]. In the second state (current limiting) in which the current limiting circuit switch 162-2 is ON, the current and voltage in the connector 120 exhibit the waveform pattern described with reference to Fig. 8. Therefore, it is determined that the external device 200 connected to the connector 120-2 does not have a short-circuit fault and has the current limiting circuit 220. Because the external device 200 has the current limiting circuit 220, current limiting operation in the power supply device 100 is unnecessary. Therefore, immediately after the determination process is completed, the load switch 130-2 is turned ON, the current limiting circuit switch 162-2 is turned OFF, and the connection state between the main power supply 110 and the connector 120 becomes the third state (direct connection).

[0088] Next, the third group will be described. In Fig. 19, in the first state (shutdown) in which the load switch 130-3 and the current limiting circuit switch 162-3 are OFF, the current in the connector 120-3 is 0 [A] and the voltage is 0 [V]. In the second state (current limiting) in which the current limiting circuit switch 162-3 is ON, the current and voltage in the connector 120 exhibit waveform patterns similar to those of the waveforms when there is a short-circuit fault in the external device 200 described with reference to Fig. 3. Therefore, it is determined that there is a short-circuit fault in the external device 200 connected to the connector 120-3. Therefore, immediately after the determination process is completed, the current limiting circuit switch 162-3 is turned OFF, and the connection state between the main power supply 110 and the connector 120 becomes the first state (shutdown).

[0089] Of the above-described groups of operations, in the first and second groups of operations, when switching from the second state to the third state, the load switch 130 is first turned ON, and then the current limiting circuit switch 162 is turned OFF. Therefore, in each group, there is a period during which the load switch 130 and the current limiting circuit switch 162 are simultaneously turned ON. This control is used to prevent the occurrence of surge voltage.

[0090] Next, the timing of operation of each group will be described. In the example shown in Fig. 19, the connection state between the main power supply 110 and the connector 120 is controlled in the order of group 1, group 2, and group 3. Here, attention is paid to the time points at which the current limiting circuit switches 162-1, 162-2, and 162-3 are turned ON. First, the current limiting circuit switch 162-1 is turned OFF, and then the current limiting circuit switch 162-2 is turned ON. Also, first, the current limiting circuit switch 162-2 is turned OFF, and then the current limiting circuit switch 162-3 is turned ON. Therefore, multiple current limiting circuit switches 162 belonging to different groups are not turned ON at the same time.

[0091] 20 is a diagram showing another example of an operation for determining whether short-circuit fault detection has occurred in the external devices 200 connected to a plurality of connectors 120 and whether the external devices 200 have current-limiting circuits 220. In the example of operation shown in FIG. 20, similar to the example of operation shown in FIG. 19, determination and control are performed for each group in turn. The example of operation shown in FIG. 20 differs from the example of operation shown in FIG. 19 in that the control unit 150 of the power supply device 100 previously acquires information indicating the determination result of short-circuit fault detection for each group and the determination result of the presence or absence of the current-limiting circuit 220 in the external devices 200. An example of such a case is when power is supplied for the second or subsequent time after a single external device 200 is connected, and the determination result from the previous power supply is stored in the memory of the control unit 150.

[0092] In the example shown in FIG. 20, the operation of the current-limiting circuit switches 162-1, 162-2 and the load switches 130-1, 130-2 in each pair is generally similar to the example shown in FIG. 19. However, because the control unit 150 holds information indicating whether each external device 200 connected to each connector 120-1, 120-2 has a current-limiting circuit 220, the control unit 150 does not determine whether the current-limiting circuit 220 exists. Therefore, compared to the operation shown in FIG. 19, the period of the second state (current limiting) in the second pair is shortened. In addition, the control unit 150 holds information indicating that a short-circuit fault exists in the external device 200 connected to the connector 120-3 in the third pair. Therefore, the connection state between the main power supply 110 and the connector 120 in the third pair remains in the first state (shut-off), and no determination of a short-circuit fault is made.

[0093] FIG. 21 illustrates another example of an operation for determining whether a short-circuit fault has been detected in the external devices 200 connected to multiple connectors 120 and whether the external devices 200 have current-limiting circuits 220. In the operation example illustrated in FIG. 21, the control unit 150 acquires in advance information indicating the determination result of whether the current-limiting circuits 220 are present in each of the external devices 200 connected to the connectors 120-1, 120-2, and 120-3. Therefore, it is not necessary to determine the presence or absence of the current-limiting circuits 220 when starting power supply. Therefore, in the example illustrated in FIG. 21, unlike the examples illustrated in FIGS. 19 and 20, the current-limiting circuit switches 162-1, 162-2, and 162-3 and the load switches 130-1, 130-2, and 130-3 in each group are simultaneously controlled. Here, it is assumed that all of the external devices 200 have current-limiting circuits 220.

[0094] Also, it is assumed here that there is no short-circuit fault in any of the external devices 200. In this case, as shown in Fig. 21, after the presence or absence of a short-circuit fault is determined in each pair in the second state (current limiting), the pair immediately transitions to the third state (direct connection). Therefore, the time required for the connection state between the main power supply 110 and the connector 120 in each pair to transition to the third state (direct connection) is significantly reduced.

[0095] In the operation example shown in Fig. 21, it is assumed that there is no short-circuit fault in any of the external devices 200. Here, if there is a short-circuit fault in any of the external devices 200, in the second state (current limiting), the voltages of all the sets of connectors 120-1, 120-2, 120-3 remain at 0 [V]. For this reason, it is possible to determine that there is a short-circuit fault in any of the external devices 200, but it is not possible to identify which external device 200 has the short-circuit fault. Therefore, when power supply to the external devices 200 starts, it is possible to first simultaneously control each set, and if it is detected that there is a short-circuit fault in any of the external devices 200, to once again sequentially control each set.

[0096] 22 is a diagram showing another example of an operation for determining whether a short-circuit fault has been detected in the external devices 200 connected to a plurality of connectors 120 and whether the external devices 200 have a current-limiting circuit 220. In the operation example shown in FIG. 22, first, the current-limiting circuit switches 162-1, 162-2, and 162-3 and the load switches 130-1, 130-2, and 130-3 of each set are controlled simultaneously. Then, when a short-circuit fault is detected in any of the external devices 200 in the second state (current limiting), the current-limiting circuit switches 162-1, 162-2, and 162-3 and the load switches 130-1, 130-2, and 130-3 of each set are controlled sequentially. Through this control, it is possible to identify which external device 200 has the short-circuit fault (in the example shown in FIG. 22, the external device 200 connected to the connector 120-3 has the short-circuit fault).

[0097] In the above operation example, whether or not the external device 200 has a short-circuit fault is determined based on a change in the connector voltage in the second state (current limiting). Alternatively, whether or not the external device 200 has a short-circuit fault may be determined based on a change in the current in the connectors 120-1, 120-2, and 120-3 in the second state (current limiting). As shown in FIG. 22, in the second state (current limiting), the current value in the connector 120-3 connected to the external device 200 having a short-circuit fault is maintained at a high level. In contrast, the current values ​​in the other connectors 120-1 and 120-2 are unchanged. Therefore, by performing a determination based on the change in the current in the connectors 120-1, 120-2, and 120-3 in the second state (current limiting), it is possible to immediately identify which external device 200 has a short-circuit fault.

[0098] <Modification> The power supply device 100 of the second embodiment is configured so that one resistor 161 is shared in the current limiting circuits corresponding to the connectors 120. However, it is also possible to adopt a configuration in which voltage detection means is shared.

[0099] Fig. 23 is a diagram showing an example of a configuration in which a voltage detection means is shared in the power supply device 100 of the second embodiment. In the configuration shown in Fig. 23, one switch 163 is provided between a resistor 161 and multiple switches 162. A conductor branch is formed between the switch 163 and the switch 162, and the branch is connected to each of the multiple switches 162. In such a configuration, a voltage detection position may be set between the switch 163 and the branch position. Note that the switch 163 may also be referred to as a current limiting circuit switch 163 to distinguish it from the load switch 130.

[0100] Fig. 24 is a diagram showing the current waveform and voltage waveform of the connector 120 in response to switch control at the start of power supply in the configuration shown in Fig. 23. Fig. 24 shows the state changes at the start of power supply in one set of connector 120, load switch 130, and current limiting circuit switch 162. Specifically, the diagram shows the state changes of the current limiting circuit switch 162, the current limiting circuit switch 163, and the load switch 130, and the change in the connection state between the main power supply 110 and the connector 120 (denoted as "current limiting circuit of power supply device" in the diagram). Also shown are the current and voltage waveforms when the external device 200 connected to the connector 120 does not have the current limiting circuit 220, and the current and voltage waveforms when the external device 200 has the current limiting circuit 220.

[0101] 24, in the first state (shutoff) in which the current limiting circuit switches 162 and 163 and the load switch 130 are OFF, the current through the connector 120 is 0 [A]. Also, the voltage detected at the voltage detection position described with reference to FIG. 23 is 0 [V]. Here, the connector voltage does not match the detected voltage.

[0102] When power supply starts, first current limiting circuit switch 163 is turned ON, and then current limiting circuit switch 162 is turned ON, thereby bringing the connection state between main power supply 110 and connector 120 into the second state (current limiting). Here, when current limiting circuit switch 163 is turned ON, the voltage detected at the voltage detection position described with reference to Fig. 23 rises and coincides with the connector voltage.

[0103] In the second state (current limiting), the current in the connector 120 and the voltage detected at the detection position shown in Fig. 23 show the waveform pattern described with reference to Fig. 9 when the external device 200 does not have the current limiting circuit 220. Also, when the external device 200 has the current limiting circuit 220, they show the waveform pattern described with reference to Fig. 10.

[0104] Third embodiment <Power supply configuration> Figure 25 is a diagram showing the configuration of a power supply device according to the third embodiment. The power supply device 100 includes a main power supply 110, a plurality of connectors 120, a plurality of load switches 130, a current limiting circuit 140, and a control unit 150. The connectors 120 and the load switches 130 form individual corresponding pairs, and each pair of the connector 120 and the load switch 130 is connected in parallel to the main power supply 110 via the current limiting circuit 140. Therefore, in the power supply device 100 shown in Figure 25, each pair of the connector 120 and the load switch 130 shares one current limiting circuit 140.

[0105] The main power supply 110, connector 120, load switch 130, and control unit 150 are the same as those in the first and second embodiments described with reference to FIG. 1. Therefore, the same reference numerals are used for these components, and their description will be omitted. Furthermore, in the configuration and operation of the power supply device 100 in the third embodiment, descriptions of the same components as those in the power supply device 100 in the first and second embodiments, such as the determination procedure related to the external device 200 and the procedure for controlling the connection state between the main power supply 110 and connector 120, will be omitted as appropriate. The load switch 130 in the third embodiment is an example of a fifth switch.

[0106] The current limiting circuit 140 includes a resistor 141 and a switch 142 connected in parallel to the resistor 141. Hereinafter, the switch 142 provided in the current limiting circuit 140 may be referred to as a current limiting circuit switch 142 to distinguish it from the load switch 130. The current limiting circuit 140 in the third embodiment is an example of a second current limiting circuit. The switch 142 is an example of a sixth switch.

[0107] Fig. 26 is a diagram showing the correspondence between the first to third states and the ON / OFF states of the load switch 130 and the current limiting circuit switch 142. Referring to Fig. 26, in the first state (shutdown), the load switch 130 is OFF, and the state of the current limiting circuit switch 142 is not specified. In the second state (current limiting), the load switch 130 is ON, and the current limiting circuit switch 142 is OFF. In the third state (direct connection), the load switch 130 is ON, and the current limiting circuit switch 142 is ON.

[0108] <Determining the Connection State Between the Main Power Supply 110 and the Connector 120 and Supplying Power to the External Device 200> 27 to 30, the process by the control unit 150 to determine the connection state between the main power supply 110 and the connector 120 and the power supply to the external device 200 will be described. In the third embodiment, the operation at the start of power supply is performed in two stages. In the first stage, only a determination is made as to whether the external device 200 connected to the connector 120 has a current-limiting circuit 220. Then, based on the determination result in the first stage, in the second stage, the presence or absence of a short-circuit fault in the external device 200 is determined, and power is supplied to the external device 200 according to the determination result. FIG. 27 shows the operation of the first stage, and FIGS. 28 to 30 show the operation of the second stage.

[0109] 27 to 30 show three sets of connectors 120 and load switches 130 for comparison. Each set is distinguished by adding a suffix 1, 2, or 3 to each component. For example, they are described as load switch 130-1 and connector 120-1. The suffixes 1, 2, and 3 are used to identify each set. For example, a set including load switch 130-1 and connector 120-1 is referred to as set 1, and a set including load switch 130-2 and connector 120-2 is referred to as set 2. When it is not necessary to distinguish between sets of components, they are simply described as load switch 130, connector 120, etc.

[0110] 27 is a diagram showing an example of an operation for determining whether or not the external device 200 connected to a plurality of connectors 120 has a current-limiting circuit 220. This corresponds to the first stage of operation described above. In the operation shown in FIG. 27, the control of each set of load switches 130 and the determination of the presence or absence of a current-limiting circuit 220 are performed for each set in turn.

[0111] Referring to FIG. 27, in the first state (shutoff) in which the current limiting circuit switch 142 and the load switch 130 are OFF, the current is 0 [A] and the voltage is 0 [V] in all of the connectors 120-1, 120-2, and 120-3.

[0112] Next, the load switches 130-1, 130-2, and 130-3 are sequentially turned ON, and it is determined whether or not each of the external devices 200 connected to the connectors 120-1, 120-2, and 120-3 has a current limiting circuit 220. In FIG. 27, when the load switch 130-1 is turned ON, the connection state of the connector 120-1 changes to the second state (current limiting). In the example shown in FIG. 27, the current value of the connector 120-1 jumps up and then attenuates, and the voltage value gradually increases. Here, it is determined from the manner in which the voltage value increases that the external device 200 connected to the connector 120-1 does not have a current limiting circuit 220. It is also clear that the external device 200 connected to the connector 120-1 does not have a short-circuit fault at this point. After this, the load switch 130-1 is turned OFF, and the connection state of the connector 120-1 returns to the first state (shut-off).

[0113] Next, when the load switch 130-2 is turned ON, the connection state of the connector 120-2 changes to the second state (current limiting). In the example shown in FIG. 27, the current value of the connector 120-2 jumps up and then attenuates, and the voltage value gradually increases. Here, it is assumed that it is determined from the manner in which the voltage value increases that the external device 200 connected to the connector 120-2 has a current limiting circuit 220. It is also clear that there is no short-circuit fault in the external device 200 connected to the connector 120-2 at this point. After this, the load switch 130-2 turns OFF, and the connection state of the connector 120-2 returns to the first state (disconnected).

[0114] Next, when the load switch 130-3 is turned ON, the connection state of the connector 120-3 changes to the second state (current limiting). In the example shown in Fig. 27, the current value of the connector 120-3 remains high, and the voltage value remains at 0 [V]. Therefore, it is determined that a short-circuit fault has occurred in the external device 200 connected to the connector 120-2. After this, the load switch 130-3 is turned OFF, and the connection state of the connector 120-3 returns to the first state (disconnected).

[0115] Fig. 28 is a diagram showing an example of an operation for starting power supply to external device 200. This corresponds to the second stage of operation described above. Fig. 28 also shows an operation performed in accordance with the determination result of Fig. 27. At the start of this operation, control unit 150 of power supply device 100 has acquired information on the presence or absence of current limiting circuits 220 in each of external devices 200 connected to connectors 120-1 and 120-2, and on the presence of a short-circuit fault in external device 200 connected to connector 120-3.

[0116] Referring to FIG. 28, in the first state (shutoff) in which the current limiting circuit switch 142 and the load switch 130 are OFF, the current is 0 [A] and the voltage is 0 [V] in all of the connectors 120-1, 120-2, and 120-3.

[0117] Next, since it is known whether or not the current limiting circuit 220 of the external device 200 connected to the connectors 120-1 and 120-2 is present, the load switches 130-1 and 130-2 are simultaneously turned ON. Then, the connection state of the connectors 120-1 and 120-2 becomes the second state (current limiting). In contrast, since it is known that the external device 200 connected to the connector 120-3 has a short-circuit fault, the load switch 130-3 is not turned ON, and the connection state of the connector 120-3 remains in the first state (shut-off).

[0118] In the second state (current limiting), the current value of the connector 120-1 jumps up and then decays, and the voltage value gradually increases. Therefore, it is clear that there is no short-circuit fault in the external device 200 connected to the connector 120-1. Furthermore, since it is clear that the external device 200 connected to the connector 120-1 does not have a current limiting circuit 220, the current limiting circuit switch 142 remains OFF until the predetermined condition described with reference to FIG. 11(B) is met, and the second state (current limiting) continues. After this, when the predetermined condition is met, the current limiting circuit switch 142 turns ON, and the connection state of the connector 120-1 becomes the third state (direct connection).

[0119] Furthermore, in the second state (current limiting), the current value of the connector 120-2 jumps up and then decays, and the voltage value gradually increases. Therefore, it can be seen that there is no short-circuit fault in the external device 200 connected to the connector 120-2. Furthermore, it can be seen that the external device 200 connected to the connector 120-2 has a current limiting circuit 220, but the current limiting circuit switch 142 in the current limiting circuit 140 of the power supply device 100 cannot individually handle each connector 120. Therefore, after the determination process for the connector 120-2 is completed, it is not possible to immediately turn on the current limiting circuit switch 142 and transition to the third state (direct connection). Therefore, the load switch 130-2 is temporarily turned off, and the connection state of the connector 120-2 becomes the first state (disconnected). Then, after the connection state of the connector 120-1 becomes the third state (direct connection), the load switch 130-2 is turned on again, and the connection state of the connector 120-2 becomes the third state (direct connection).

[0120] Fig. 29 is a diagram showing another example of operation for starting power supply to external device 200. This corresponds to the second stage of operation described above. Fig. 29 shows the operation when it is determined in the first stage of operation that all external devices 200 connected to connectors 120-1, 120-2, and 120-3 have current-limiting circuits 220. At the start of this operation, control unit 150 of power supply apparatus 100 acquires information on the presence or absence of current-limiting circuits 220 in each of external devices 200 connected to connectors 120-1, 120-2, and 120-3.

[0121] Referring to FIG. 29, in the first state (shutoff) in which the current limiting circuit switch 142 and the load switch 130 are OFF, the current is 0 [A] and the voltage is 0 [V] in all of the connectors 120-1, 120-2, and 120-3.

[0122] Next, since it is known whether or not the current limiting circuit 220 of the external device 200 connected to the connectors 120-1, 120-2, and 120-3 is present, the load switches 130-1, 130-2, and 130-3 are simultaneously turned ON. Then, the connection state of the connectors 120-1, 120-2, and 120-3 becomes the second state (current limiting).

[0123] In the second state (current limiting), the current values ​​of the connectors 120-1, 120-2, and 120-3 jump up and then attenuate, and the voltage values ​​gradually increase. Therefore, it can be seen that there is no short-circuit fault in any of the external devices 200 connected to the connectors 120-1, 120-2, and 120-3. Furthermore, since it is known that all of the external devices 200 connected to the connectors 120-1, 120-2, and 120-3 have current limiting circuits 220, immediately after the determination process in the second state (current limiting) is completed, the current limiting circuit switch 142 is turned ON, and the connection state of the connectors 120-1, 120-2, and 120-3 becomes the third state (direct connection).

[0124] Fig. 30 is a diagram showing another example of operation for starting power supply to external device 200. This corresponds to the second stage of operation described above. Fig. 30 shows the operation when it is determined in the first stage of operation that none of external devices 200 connected to connectors 120-1, 120-2, 120-3 has a current limiting circuit 220. At the start of this operation, control unit 150 of power supply apparatus 100 acquires information on the presence or absence of a current limiting circuit 220 in each of external devices 200 connected to connectors 120-1, 120-2, 120-3.

[0125] Referring to FIG. 30, in the first state (shutoff) in which the current limiting circuit switch 142 and the load switch 130 are OFF, the current is 0 [A] and the voltage is 0 [V] in all of the connectors 120-1, 120-2, and 120-3.

[0126] Next, since it is known whether or not the current limiting circuit 220 of the external device 200 connected to the connectors 120-1, 120-2, and 120-3 is present, the load switches 130-1, 130-2, and 130-3 are simultaneously turned ON. Then, the connection state of the connectors 120-1, 120-2, and 120-3 becomes the second state (current limiting).

[0127] In the second state (current limiting), the current values ​​of the connectors 120-1, 120-2, and 120-3 jump up and then decay, and the voltage values ​​gradually increase. Therefore, it can be seen that none of the external devices 200 connected to the connectors 120-1, 120-2, and 120-3 have a short-circuit fault. Furthermore, since it can be seen that none of the external devices 200 connected to the connectors 120-1, 120-2, and 120-3 have a current limiting circuit 220, after the determination process in the second state (current limiting) is completed, the current limiting circuit switch 142 remains OFF until the predetermined condition described with reference to FIG. 11(B) is met, and the second state (current limiting) continues. After this, when the predetermined condition is met, the current limiting circuit switch 142 turns ON, and the connection state of the connectors 120-1, 120-2, and 120-3 becomes the third state (direct connection).

[0128] Fourth embodiment In the first to third embodiments, the control when the power supply device 100 and the external device 200 are connected has been described. However, even when the external device 200 is detached from the power supply device 100, a malfunction may occur due to the power supply device 100 continuing to supply power to the external device 200. For example, a malfunction may occur in which an arc discharge occurs when the contacts are opened, causing the contacts to weld. Therefore, in the power supply device 100 according to the present disclosure, it is conceivable to suppress the occurrence of the above malfunction by controlling the electrical connection state between the main power supply 110 and the connector 120 when the external device 200 is detached from the power supply device 100. Hereinafter, as a fourth embodiment, a power supply device 100 that controls the connection state between the main power supply 110 and the connector 120 when the contacts are opened will be described.

[0129] <Power supply configuration> In the fourth embodiment, the power supply device 100 is not limited to a specific configuration as long as it can control the connection state between the main power supply 110 and the connector 120 to any one of a first state, a second state, and a third state. Therefore, the configuration of the power supply device 100 in the fourth embodiment may be any of the configurations used in the first to third embodiments. In the following description, components such as the power supply device 100, the main power supply 110, the connector 120, and the control unit 150 provided in the power supply device 100, the external device 200, and the connector 201 of the external device 200 will be described using the same reference numerals as those used in the first to third embodiments.

[0130] In the first to third embodiments, the power supply device 100 has a configuration including a plurality of connectors 120, but in the fourth embodiment, the number of connectors 120 is not limited. This is because the objective of the fourth embodiment is to suppress problems that may occur when the external device 200 is removed from the power supply device 100 using a single connector 120. The following description will be given assuming that the power supply device 100 has one connector 120.

[0131] In the fourth embodiment, the power supply device 100 includes a connector information acquisition unit that acquires connector information. The connector information is information relating to the mechanical connection state between the connector 120 and the external device 200. Specifically, the connector information is information indicating whether the connection state between the connector 120 and the external device 200 is a first connection state, a second connection state, or a third connection state.

[0132] The first connection state is a state in which the connector 120 and the external device 200 are connected, and removal of the external device 200 is not expected. The second connection state is a state in which the connector 120 and the external device 200 are connected, but removal of the external device 200 is expected. In other words, the second connection state indicates that the connector 120 and the external device 200 are in the process of being switched from connection to release. The third connection state is a state in which the external device 200 is removed (disconnected) from the connector 120.

[0133] The control unit 150 of the power supply device 100 acquires connector information via a connector information acquisition means. Then, based on the acquired connector information, the control unit 150 controls the connection state between the main power supply 110 and the connector 120. A specific example of the connector information acquisition means will be described later.

[0134] <Example of control by the control unit 150 when the contacts are opened> 31 is a diagram showing the operation of the power supply device 100 when the contacts are opened. Here, it is assumed that, as an initial state, the external device 200 is connected to the connector 120 and power is being supplied. In other words, the mechanical connection state between the connector 120 and the external device 200 is the first connection state. At this time, the control unit 150 controls the electrical connection state between the main power supply 110 and the connector 120 to the third state.

[0135] The control unit 150 determines the mechanical connection state between the connector 120 and the external device 200 based on the connector information acquired via the connector information acquisition means (S101). This determination is made when a predetermined execution condition is satisfied. Specifically, for example, the determination is made periodically. Alternatively, the determination may be made when a predetermined event occurs as a trigger for making the determination.

[0136] If it is determined in S101 that the mechanical connection state remains in the first connection state (NO in S102), the control unit 150 again waits until the execution condition for determining the connection state is satisfied. On the other hand, if it is determined in S101 that the mechanical connection state has transitioned to the second connection state (YES in S102), the control unit 150 switches the electrical connection state between the main power supply 110 and the connector 120 from the third state (direct connection) to the second state (current limiting) (S103). In the second state (current limiting), the main power supply 110 and the connector 120 are connected via a resistor, and the current supplied to the external device 200 is limited. This prevents problems such as contact welding caused by arc discharge when the contacts are opened.

[0137] After switching the electrical connection state between main power supply 110 and connector 120 to the second state (current limiting), control unit 150 waits for a predetermined time to elapse (NO in S104). Then, when the predetermined time has elapsed (YES in S104), control unit 150 switches the electrical connection state between main power supply 110 and connector 120 from the second state (current limiting) to the first state (shutoff) (S105).

[0138] In the above operation, the control unit 150 does not immediately change from the third state (direct connection) to the first state (shutdown) in S103, but changes to the second state (current limiting). This is because, at the stage when the mechanical connection state between the connector 120 and the external device 200 becomes the second connection state (if YES in S102), the external device 200 is not necessarily immediately detached from the connector 120 (transition to the third connection state). For this reason, instead of directly transitioning from the third state (direct connection) to the first state (shutdown) to stop the power supply, the control unit 150 changes to the second state (current limiting). Since the power supply current is limited by changing to the second state (current limiting), even if the external device 200 is detached from the connector 120 in this state, the occurrence of malfunctions due to arc discharge is suppressed.

[0139] Furthermore, in the above operation, the control unit 150 switches the electrical connection state between the main power supply 110 and the connector 120 to the first state (shut-off) after a predetermined time has elapsed since switching to the second state (current limiting) in S103 (S104, S105). When the mechanical connection state between the connector 120 and the external device 200 becomes the second connection state, there is a high possibility that the external device 200 will be detached from the connector 120 (becoming the third connection state) as a series of operations. For this reason, the transition condition for transitioning from the second state (current limiting) to the first state (shut-off) does not use connector information, but rather the elapse of a predetermined time.

[0140] <Specific examples of connector information acquisition methods> Specific examples of the connector information acquisition means will be described below. The connector information acquisition means acquires connector information that indicates the connection state between the connector 120 and the external device 200. The connector 120 and the external device 200 are provided with a configuration for generating the connector information. Here, two specific examples will be given as configuration examples of the connector information acquisition means.

[0141] Example 1 In the first specific example, the connector 120 is provided with a locking mechanism that locks the connection between the connector 120 and the external device 200, and information indicating the state of the locking mechanism is acquired as connector information. The structure of the locking mechanism itself is not particularly limited, and various existing locking mechanisms can be used. For example, a locking mechanism using a bayonet lock, screw lock, snap-in lock, push-pull lock, latch lock, lever lock, etc. can be used.

[0142] The locking mechanism is provided with a means for acquiring information (hereinafter referred to as "status information") indicating whether the locking mechanism is in a locked state (locked state) or an unlocked state (released state). There are no specific limitations on the configuration of this status information acquiring means, as long as it is capable of acquiring the status information. For example, the locking mechanism may be provided with an electrical contact that is ON in the locked state and OFF in the unlocked state, and the electrical signal corresponding to the ON / OFF state of this contact may be acquired as the status information.

[0143] 32 is a diagram showing the relationship between the lock state of the locking mechanism provided in connector 120 and the control of power supply device 100. Control unit 150 determines the lock state of the locking mechanism based on, for example, the state information described above. Control unit 150 then determines the connection state between connector 120 and external device 200 based on the lock state of the locking mechanism, and controls the connection state between main power supply 110 and connector 120.

[0144] In the example shown in FIG. 32, when the locking mechanism is in the locked state, the control unit 150 determines that the mechanical connection state between the connector 120 and the external device 200 is the first connection state. Then, the control unit 150 controls the electrical connection state between the main power supply 110 and the connector 120 to the third state (direct connection). On the other hand, when the locking mechanism is in the released state, the control unit 150 determines that the mechanical connection state between the connector 120 and the external device 200 is the second connection state. Then, the control unit 150 controls the electrical connection state between the main power supply 110 and the connector 120 to the second state (current limiting). Note that when the control unit 150 determines that the mechanical connection state between the connector 120 and the external device 200 has changed from the first connection state to the second connection state, it may set the electrical connection state between the main power supply 110 and the connector 120 to the second state (current limiting), and then switch it to the first state (shutoff) after a predetermined time has elapsed.

[0145] Therefore, when the external device 200 is removed from the connector 120 of the power supply device 100 while the connector 201 of the external device 200 is connected, the control unit 150 performs control in the following procedure. First, the locking mechanism of the connector 120 is released, and accordingly, the electrical connection state between the main power supply 110 and the connector 120 transitions from the third state (direct connection) to the second state (current limiting). Then, the connector 201 of the external device 200 is removed from the connector 120 whose locking mechanism has been released.

[0146] Note that even when the external device 200 is connected to the connector 120, the connection between the main power supply 110 and the connector 120 may be established based on the state of the locking mechanism. For example, the following control may be performed. When the external device 200 is connected to the connector 120, the locking mechanism is in the unlocked state. The control unit 150 determines that the mechanical connection state between the connector 120 and the external device 200 is the second connection state based on the locking mechanism being in the unlocked state. The control unit 150 then controls the electrical connection state between the main power supply 110 and the connector 120 to the second state (current limiting). Next, when the locking mechanism is operated to enter the locked state, the control unit 150 determines that the mechanical connection state between the connector 120 and the external device 200 is the first connection state based on the locking mechanism being in the locked state. The control unit 150 then controls the electrical connection state between the main power supply 110 and the connector 120 to the third state (direct connection). In addition, the control unit 150 may control the connection state between the main power supply 110 and the connector 120 to the third state (direct connection) based on the fact that the locking mechanism is in the locked state and that a predetermined time has elapsed since the electrical connection state between the main power supply 110 and the connector 120 was controlled to the second state (current limiting).

[0147] Example 2 In the second specific example, the connector 120 of the power supply device 100 and the connector 201 of the external device 200 are provided with contacts (hereinafter referred to as "non-power supply contacts") that come into contact when the connector 120 and the external device 200 are connected, in addition to the power supply contacts. Information indicating the contact state of the power supply contacts and the non-power supply contacts is obtained as connector information. As an example, consider a configuration in which the connector 120 of the power supply device 100 has a socket 300, and the connector 201 of the external device 200 has a plug 400 that is attached to the socket 300, and the socket 300 and the plug 400 have non-power supply contacts.

[0148] Figure 33 shows an example of the configuration of socket 300 and plug 400 in specific example 2, where Figure 33(A) shows the state in which socket 300 and plug 400 are fully attached, Figure 33(B) shows the state in which the contact of the non-power-supply contacts has been cut, and Figure 33(C) shows the state in which plug 400 has been removed from socket 300.

[0149] 33, plug 400 is provided with power feed pin 410, which is a pin for feeding power, and information pin 420, which is a pin used as a non-powered contact. Socket 300 is also provided with insertion opening 310 into which power feed pin 410 is inserted, and insertion opening 320 into which information pin 420 is inserted. In the example shown in Fig. 33, information pin 420 is provided as the non-powered contact, not as a contact that simply comes into contact when plug 400 is attached to socket 300, but as an information pin that is inserted into insertion opening 320 of socket 300. This allows the non-powered contacts to reliably come into contact when plug 400 is attached to socket 300, and can prevent the contact of the non-powered contact from becoming unstable.

[0150] 33(A), when the plug 400 is completely inserted into the socket 300, both the power feed pin 410 and the information pin 420 are inserted into the insertion opening 310 and the insertion opening 320, respectively.

[0151] When plug 400 is removed from socket 300, as shown in Figure 33(B), short information pin 420 comes out of insertion opening 320 before long power supply pin 410. In this state, power supply pin 410 continues to be in contact, and only information pin 420, which serves as a non-power supply contact, is out of contact.

[0152] As the operation of removing the plug 400 from the socket 300 progresses further, the power supply pin 410 also comes out of the insertion port 310, as shown in Figure 33 (C), and the plug 400 (external device 200) is completely removed from the socket 300 (power supply 100).

[0153] Although not specifically shown, the contacts of insertion port 320 of socket 300 are provided with means for acquiring information (hereinafter referred to as "contact information") indicating whether or not information pin 420 is in contact (contact state). The means for acquiring contact information may be, for example, an electrical structure that turns ON when information pin 420 makes contact with the contacts of insertion port 320 and turns OFF when information pin 420 moves away, and this ON / OFF electrical signal may be acquired as contact information. Similarly, the contacts of insertion port 310 of socket 300 may also be provided with means for acquiring information indicating the contact state of power feed pin 410, so that it can be determined whether power feed pin 410 is inserted into (in contact with) insertion port 310.

[0154] 34 is a diagram showing the relationship between the connection state between connector 120 and external device 200 and the control of power supply device 100. Control unit 150 determines the contact state of the non-power-supply contact based on, for example, the contact information as described above. Control unit 150 then determines the connection state between connector 120 and external device 200 according to the contact state of the non-power-supply contact, and controls the connection state between main power supply 110 and connector 120.

[0155] 34, when power feed pin 410 and information pin 420 are in contact with (inserted into) insertion slots 310, 320, control unit 150 determines that the mechanical connection state between connector 120 and external device 200 is the first connection state. Then, control unit 150 controls the electrical connection state between main power supply 110 and connector 120 to the third state (direct connection). Note that while the power feed pin 410 and information pin 420 are in contact with insertion slots 310, 320 in this example, it is sufficient to determine that information pin 420 is in contact with the insertion slot. This is because when short information pin 420 is in contact with insertion slot 320, long power feed pin 410 is always in contact with insertion slot 310.

[0156] Furthermore, when only the power feed pin 410 is in contact with the insertion port 310 and the information pin 420 is not in contact with the insertion port 320, the control unit 150 determines that the mechanical connection state between the connector 120 and the external device 200 is the second connection state. The control unit 150 then controls the electrical connection state between the main power supply 110 and the connector 120 to the second state (current limiting). When neither the power feed pin 410 nor the information pin 420 is in contact with the insertion port 310, 320, the connector 120 and the external device 200 are completely separated, and the control unit 150 controls the electrical connection state between the main power supply 110 and the connector 120 to the first state (shut off). Note that when control unit 150 determines that the mechanical connection state between connector 120 and external device 200 has changed from the first connection state to the second connection state, it may control the electrical connection state between main power supply 110 and connector 120 to the second state (current limiting), and then switch it back to the first state (shutoff) after a predetermined time has elapsed. Also, when neither power feed pin 410 nor information pin 420 is in contact with insertion slots 310, 320, control unit 150 may control the electrical connection state between main power supply 110 and connector 120 to the second state (current limiting).

[0157] Therefore, when the external device 200 is removed from a state in which the connector 201 of the external device 200 is connected to the connector 120 of the power supply device 100, the control unit 150 performs control in the following procedure. When the plug 400 is removed from the socket 300 in order to remove the external device 200 from the connector 120, first, the information pin 420 and the insertion port 320 are no longer in contact with each other, and accordingly, the electrical connection state between the main power supply 110 and the connector 120 transitions from the third state (direct connection) to the second state (current limiting). Then, when the plug 400 is further removed from the socket 300, the power supply pin 410 and the insertion port 310 are no longer in contact with each other, and the connector 201 of the external device 200 is removed from the connector 120.

[0158] Note that when the external device 200 is connected to the connector 120, the connection between the main power supply 110 and the connector 120 may be established based on the contact state between the power supply pin 410 and the information pin 420 and the insertion ports 310, 320. For example, the following control may be performed. When the plug 400 is inserted into the socket 300 to connect the external device 200 to the connector 120, the power supply pin 410 first comes into contact with the insertion port 310. The control unit 150 determines that the mechanical connection state between the connector 120 and the external device 200 is the second connection state based on the state in which only the power supply pin 410 is in contact with the insertion port 310. The control unit 150 then controls the electrical connection state between the main power supply 110 and the connector 120 to the second state (current limiting). Next, when the plug 400 is further pushed into the socket 300, the information pin 420 comes into contact with the insertion port 320. Control unit 150 determines that the mechanical connection state between connector 120 and external device 200 is the first connection state based on the state in which power feed pin 410 and information pin 420 are in contact with insertion ports 310, 320. Control unit 150 then controls the electrical connection state between main power supply 110 and connector 120 to a third state (direct connection). Note that control unit 150 may also control the electrical connection state between main power supply 110 and connector 120 to the third state (direct connection) based on the state in which power feed pin 410 and information pin 420 are in contact with insertion ports 310, 320 and a predetermined time has elapsed since control unit 150 controlled the electrical connection state between main power supply 110 and connector 120 to the second state (current limiting).

[0159] <Effects> The power supply device 100 of the present disclosure includes a main power supply 110 capable of supplying DC power, two or more connectors 120 capable of supplying power from the main power supply 110 without power conversion, and a control unit 150 that switches the connection state between the main power supply 110 and the connectors 120, the control unit 150 switching the connection state between a first state in which the main power supply 110 and the connectors 120 are not connected, a second state in which the main power supply 110 and the connectors 120 are connected via a resistor 141, and a third state in which the main power supply 110 and the connectors 120 are connected without via the resistor 141. In this case, it is possible to prevent excessive current from flowing through the power supply device when the device connected to the connector is connected, regardless of the presence or absence of a malfunction or the configuration of the device connected to the connector. Here, the device further includes an acquisition means for acquiring information regarding whether or not a current limiting operation by the resistor 141 is required, and when the information indicates that a current limiting operation by the resistor 141 is not required, the control unit 150 switches the connection state so that the second state is maintained for a shorter time than when the information indicates that a current limiting operation by the resistor 141 is required. In this case, unnecessary current limiting operations can be suppressed, and the time required from the start of power supply to the steady state can be shortened. Furthermore, the acquisition means acquires the information from the device connected to the connector 120. In this case, information regarding the necessity of current limiting operation can be obtained in advance without performing a process of detecting information when power is supplied to the device. The acquisition means also acquires the voltage of the connector 120 in the first state before changing from the first state to the second state as a first voltage (v c1 (0)), and the voltage of the connector 120 when a first time (Δt) has elapsed since the first state was changed to the second state is defined as a second voltage (v c1 (Δt)), and the voltage of the connector 120 when a second time (2Δt) that is twice the first time has elapsed since the first state was changed to the second state is defined as a third voltage (v c1When the voltage difference (Δv1) between the first voltage and the second voltage is set to (2Δt), the information is determined based on the ratio of the first voltage difference (Δv1) between the first voltage and the second voltage to the second voltage difference (Δv2) between the second voltage and the third voltage. In this case, information regarding the necessity of current-limiting operation can be obtained based on the change in voltage at connector 120 when power supply to the device starts. The power supply further includes two or more first current-limiting circuits 140 and two or more first switches 130, each of which includes the resistor 141 and a second switch 142 connected in parallel to the resistor 141, and has one end connected to the output of the main power supply 110 and the other end connected to the connector 120 via the first switch 130, and the control unit 150 turns off the first switch 130 connected to the connector 120 in the first state in which the main power supply 110 and the connector 120 are not connected, In the second state in which the main power supply 110 and the connector 120 are connected via the resistor 141, the first switch 130 connected to the connector 120 is turned on and the second switch 142 of the first current limiting circuit 140 connected to the first switch 130 is turned off, and in the third state in which the main power supply 110 and the connector 120 are connected without the resistor 141, the first switch 130 connected to the connector 120 is turned on and the second switch 142 of the first current limiting circuit 140 connected to the first switch 130 is turned on. In this case, by controlling the connection state between the main power supply 110 and the connector 120 by switching the first and second switches on and off, it is possible to prevent excessive current from flowing through the power supply device when the power supply device and the device connected to the connector are connected, regardless of the presence or absence of a failure or the configuration of the device connected to the connector. The power supply 110 further includes two or more switch circuits, each of which includes a third switch 130 having one end connected to the output of the main power supply 110 and one end of the resistor 161 and the other end connected to the connector 120, and a fourth switch 162 having one end connected to the other end of the resistor 161 and the other end connected to the connector 120. In the first state in which the main power supply 110 and the connector 120 are not connected, the control unit 150 turns off the third switch 130 connected to the connector 120 and turns off the fourth switch 162 connected to the connector 120. In the second state in which the fourth switch 162 is turned off and the main power supply 110 and the connector 120 are connected via the resistor 161, the third switch 130 connected to the connector 120 is turned off and the fourth switch 162 connected to the connector 120 is turned on, and in the third state in which the main power supply 110 and the connector 120 are connected without the resistor 161, the third switch 130 connected to the connector 120 is turned on and the fourth switch 162 connected to the connector 120 is turned off. In this case, by controlling the connection state between the main power supply 110 and the connector 120 by switching the third and fourth switches on and off, it is possible to prevent excessive current from flowing through the power supply device when the power supply device is connected to the device connected to the connector, regardless of the presence or absence of a malfunction or the configuration of the device connected to the connector. The power supply further includes a second current limiting circuit 140 and two or more fifth switches 130, and the second current limiting circuit 140 includes the resistor 141 and a sixth switch 142 connected in parallel to the resistor 141, and has one end connected to the output of the main power supply 110 and the other end connected to the connector 120 via the fifth switch 130. In the first state in which the main power supply 110 and the connector 120 are not connected, the control unit 150 controls the second current limiting circuit 140 to be connected to the connector 120. In the second state in which the fifth switch 130 is turned off and the main power supply 110 and the connector 120 are connected via the resistor 141, the fifth switch 130 connected to the connector 120 is turned on and the sixth switch 142 is turned off, and in the third state in which the main power supply 110 and the connector 120 are connected without the resistor 141, the fifth switch 130 connected to the connector 120 is turned on and the sixth switch 142 is turned on. In this case, by controlling the connection state between the main power supply 110 and the connector 120 by switching the fifth and sixth switches on / off, it is possible to prevent excessive current from flowing through the power supply device when the power supply device is connected to the device connected to the connector, regardless of the presence or absence of a malfunction or the configuration of the device connected to the connector. The control unit 150 also includes a sensor that detects the voltage or current of the connector 120, and when the connection state is the second state, the control unit 150 detects whether or not there is a short circuit between the terminals of the connector 120 based on information from the sensor, switches the connection state from the first state to the second state, and then maintains the second state until it has completed detecting whether or not there is a short circuit between the terminals of the connector 120, and switches the connection state to the first state when it detects that there is a short circuit between the terminals of the connector 120. In this case, by stopping power supply when there is a short circuit between the terminals of the connector 120, it is possible to prevent failures in the power supply device. Furthermore, the power supply device 100 of the present disclosure further includes connector information acquisition means for acquiring connector information, which is information regarding the connection state between the connector 120 and the external device 200, and the control unit 150 switches between the first state, the second state, and the third state, which are connection states between the main power supply 110 and the connector 120, depending on the connection state between the connector 120 and the external device 200 specified by the connector information. In this case, depending on the connection state between the connector 120 and the external device 200, it is possible to limit the power supply to the external device 200 when there is a possibility that the external device 200 will be removed. Furthermore, when the connector information indicates that the connection between the connector 120 and the external device 200 is being switched from connection to disconnection, the control unit 150 switches the connection state between the main power supply 110 and the connector 120 from the third state to the second state. In this case, it is possible to prevent problems caused by current flowing when the external device 200 is removed from the connector 120. Furthermore, the control unit 150 switches the connection state between the main power supply 110 and the connector 120 from the third state to the second state, and then switches the connection state from the second state to the first state after a predetermined time has elapsed since the third state. In this case, after the connection state between the main power supply 110 and the connector 120 is switched to the second state, power supply can be stopped after a predetermined time has elapsed, regardless of the connection state between the connector 120 and the external device 200. Furthermore, the connector 120 includes a locking mechanism that locks the connection between the connector 120 and the external device 200, the connector information acquisition means acquires information indicating the state of the locking mechanism as the connector information, and the control unit 150 sets the connection state between the main power supply 110 and the connector 120 to the third state when the state of the locking mechanism specified by the connector information is locked, and sets the connection state between the main power supply 110 and the connector 120 to the second state when the state of the locking mechanism specified by the connector information is unlocked. In this case, depending on the state of the locking mechanism, it is possible to limit power supply to the external device 200 when there is a possibility that the external device 200 will be removed. Furthermore, the connector 120 includes a locking mechanism that locks the connection between the connector 120 and the external device 200, the connector information acquisition means acquires information indicating the state of the locking mechanism as the connector information, and the control unit 150 switches the connection state between the main power supply 110 and the connector 120 from the third state to the second state when the state of the locking mechanism specified by the connector information transitions from a locked state to an unlocked state. In this case, it is possible to prevent malfunctions caused by current flow when the external device 200 is removed from the connector 120, depending on the determination of the connection state between the connector 120 and the external device 200 based on the state of the locking mechanism. Furthermore, the connector 120 and the external device 200 are provided with contacts that come into contact when the connector 120 and the external device 200 are connected, in addition to the power supply, and the connector information acquisition means acquires, as the connector information, information indicating whether the contacts between the connector 120 and the external device 200 are in contact, and the control unit 150 sets the connection state between the main power supply 110 and the connector 120 to the third state when the connector information indicates that the contacts between the connector 120 and the external device 200 are in contact, and sets the connection state between the main power supply 110 and the connector 120 to the second state when the connector information indicates that the contacts between the connector 120 and the external device 200 are not in contact. In this case, it is possible to limit the power supply to the external device 200 when there is a possibility that the external device 200 will be removed, depending on the contact states of the contacts. Furthermore, the connector 120 and the external device 200 are provided with contacts that come into contact when the connector 120 and the external device 200 are connected, separate from the power supply, and the connector information acquisition means acquires, as the connector information, information indicating whether the contacts between the connector 120 and the external device 200 are in contact, and the control unit 150 switches the connection state between the main power supply 110 and the connector 120 from the third state to the second state when the connector information indicates that the contacts between the connector 120 and the external device 200 have transitioned from a contact state to a non-contact state. In this case, it is possible to prevent problems caused by current flow when the external device 200 is removed from the connector 120, depending on the determination of the connection state between the connector 120 and the external device 200 based on the contact state of the contacts. The power supply device 100 of the present disclosure includes a main power supply 110 capable of supplying DC power, a connector 120 capable of supplying power from the main power supply 110 without power conversion, a control unit 150 that switches a power connection state, which is a connection state between the main power supply 110 and the connector 120, and connector information acquisition means that acquires connector information, which is information regarding the connection state of the external device 200, which is a connection state between the connector 120 and the external device 200. The control unit 150 switches the power connection state according to the connection state of the external device 200 specified by the connector information, between a first state in which the main power supply 110 and the connector 120 are not connected, a second state in which the main power supply 110 and the connector 120 are connected via a resistor, or a third state in which the main power supply 110 and the connector 120 are connected without the resistor. In this case, it is possible to prevent problems caused by current flow when the external device 200 is removed from the connector 120.

[0160] Although the embodiments have been described above, the technical scope of the present disclosure is not limited to the scope of the above-described embodiments. It is clear from the claims that combinations of two or more of the above-described embodiments, and various modifications or improvements to the above-described embodiments, are also included in the technical scope of the present disclosure. [Explanation of symbols]

[0161] 100... power supply device, 110... main power supply, 120... connector, 130... load switch, 140... current limiting circuit, 141... resistor, 142... switch, 150... control unit, 161... resistor, 162... switch, 200... external device, 220... current limiting circuit, 300... socket, 310... insertion port, 320... insertion port, 400... plug, 410... power supply pin, 420... information pin

Claims

1. a main power source capable of supplying DC power; a connector capable of supplying power from the main power supply without power conversion; a control unit that switches a connection state between the main power supply and the connector, The control unit determines the connection state as follows: a first state in which the main power supply and the connector are not connected; a second state in which the main power supply and the connector are connected via a resistor; a third state in which the main power supply and the connector are connected without the resistor; Switch to one of the further comprising an acquisition means for acquiring information regarding whether or not a current limiting operation by the resistor is required; when the information indicates that a current limiting operation by the resistor is not required, the control unit switches the connection state so that a time for which the second state is maintained is shorter than a time when the information indicates that a current limiting operation by the resistor is required. power supply.

2. The power supply device according to claim 1 , wherein the acquiring means acquires the information from a device connected to the connector.

3. The acquisition means The voltage of the connector in the first state before changing from the first state to the second state is defined as a first voltage (v c1 (0)) The voltage of the connector when a first time (Δt) has elapsed since the first state was changed to the second state is defined as a second voltage (v c1 (Δt)), The voltage of the connector when a second time (2Δt) that is twice the first time has elapsed since the first state was changed to the second state is defined as a third voltage (v c1 (2Δt)), A first voltage difference (Δv 1 ), and a second voltage difference (Δv 2 determining the information based on a ratio of The power supply device of claim 1 .

4. two or more first current limiting circuits; two or more first switches; Each of the two or more first current limiting circuits the resistor; a second switch connected in parallel with the resistor; one end connected to the output of the main power supply; the other end is connected to the connector via the first switch, The control unit In the first state in which the main power supply and the connector are not connected, the first switch connected to the connector is turned off; In the second state in which the main power supply and the connector are connected via the resistor, the first switch connected to the connector is turned on, and the second switch of the first current limiting circuit connected to the first switch is turned off; In the third state in which the main power supply and the connector are connected without the resistor, the first switch connected to the connector is turned on, and the second switch of the first current limiting circuit connected to the first switch is turned on. The power supply device of claim 1 .

5. further comprising two or more switch circuits; The switch circuit a third switch having one end connected to the output of the main power supply and one end of the resistor, and the other end connected to the connector; a fourth switch having one end connected to the other end of the resistor and the other end connected to the connector; The control unit In the first state in which the main power supply and the connector are not connected, the third switch connected to the connector is turned off, and the fourth switch connected to the connector is turned off; in the second state in which the main power supply and the connector are connected via the resistor, turning off the third switch connected to the connector and turning on the fourth switch connected to the connector; In the third state in which the main power supply and the connector are connected without the resistor, the third switch connected to the connector is turned on and the fourth switch connected to the connector is turned off. The power supply device of claim 1 .

6. a second current limiting circuit; two or more fifth switches; The second current limiting circuit is the resistor; a sixth switch connected in parallel with the resistor; one end connected to the output of the main power supply; the other end is connected to the connector via the fifth switch, The control unit In the first state in which the main power supply and the connector are not connected, the fifth switch connected to the connector is turned off; In the second state in which the main power supply and the connector are connected via the resistor, the fifth switch connected to the connector is turned on and the sixth switch is turned off; In the third state in which the main power supply and the connector are connected without the resistor, the fifth switch connected to the connector is turned on, and the sixth switch is turned on. The power supply device of claim 1 .

7. a sensor for detecting a voltage or a current of the connector; The control unit When the connection state is the second state, it is detected whether or not a short circuit has occurred between the terminals of the connector based on information from the sensor; After switching the connection state from the first state to the second state, the second state is maintained until detection of whether or not a short circuit has occurred between the terminals of the connector is completed; When a short circuit is detected between the terminals of the connector, the connection state is switched to the first state. The power supply device of claim 1 .

8. A main power source capable of supplying DC power; a connector capable of supplying power from the main power supply without power conversion; a control unit that switches a power connection state, which is a connection state between the main power supply and the connector; a connector information acquisition means for acquiring connector information that is information about a device connection state that is a connection state between the connector and the device, The control unit changes the power supply connection state according to the device connection state specified by the connector information. a first state in which the main power supply and the connector are not connected; a second state in which the main power supply and the connector are connected via a resistor; a third state in which the main power supply and the connector are connected without the resistor; Switch to one of the the connector includes a locking mechanism that locks the connection between the connector and the device, the connector information acquisition means acquires, as the connector information, information indicating a state of the locking mechanism; The control unit When the state of the locking mechanism specified by the connector information is a locked state, the connection state between the main power supply and the connector is set to the third state; When the state of the locking mechanism specified by the connector information is an unlocked state, the connection state between the main power supply and the connector is set to the second state. power supply.

9. A main power source capable of supplying DC power; a connector capable of supplying power from the main power supply without power conversion; a control unit that switches a power connection state, which is a connection state between the main power supply and the connector; a connector information acquisition means for acquiring connector information that is information about a device connection state that is a connection state between the connector and the device, The control unit changes the power supply connection state according to the device connection state specified by the connector information. a first state in which the main power supply and the connector are not connected; a second state in which the main power supply and the connector are connected via a resistor; a third state in which the main power supply and the connector are connected without the resistor; Switch to one of the the connector includes a locking mechanism that locks the connection between the connector and the device, the connector information acquisition means acquires, as the connector information, information indicating a state of the locking mechanism; The control unit when the state of the locking mechanism specified by the connector information transitions from a locked state to an unlocked state, switching the connection state between the main power supply and the connector from the third state to the second state; power supply.

10. A main power source capable of supplying DC power; a connector capable of supplying power from the main power supply without power conversion; a control unit that switches a power connection state, which is a connection state between the main power supply and the connector; a connector information acquisition means for acquiring connector information that is information about a device connection state that is a connection state between the connector and the device, The control unit changes the power supply connection state according to the device connection state specified by the connector information. a first state in which the main power supply and the connector are not connected; a second state in which the main power supply and the connector are connected via a resistor; a third state in which the main power supply and the connector are connected without the resistor; Switch to one of the The connector and the device are provided with contacts that come into contact with the connector and the device when they are connected, in addition to the power supply, the connector information acquisition means acquires, as the connector information, information indicating whether the contact points between the connector and the device are in contact with each other; The control unit If the connector information is information indicating that the contact points of the connector and the device are in contact, the connection state between the main power supply and the connector is set to the third state; When the connector information indicates that the contact points of the connector and the device are not in contact, the connection state between the main power supply and the connector is set to the second state. power supply.

11. A main power source capable of supplying DC power; a connector capable of supplying power from the main power supply without power conversion; a control unit that switches a power connection state, which is a connection state between the main power supply and the connector; a connector information acquisition means for acquiring connector information that is information about a device connection state that is a connection state between the connector and the device, The control unit changes the power supply connection state according to the device connection state specified by the connector information. a first state in which the main power supply and the connector are not connected; a second state in which the main power supply and the connector are connected via a resistor; a third state in which the main power supply and the connector are connected without the resistor; Switch to one of the The connector and the device are provided with contacts that come into contact with the connector and the device when they are connected, in addition to the power supply, the connector information acquisition means acquires, as the connector information, information indicating whether the contact points between the connector and the device are in contact with each other; The control unit When the connector information indicates that the contact point between the connector and the device has transitioned from a contact state to a non-contact state, the connection state between the main power supply and the connector is switched from the third state to the second state. power supply.

12. A power supply device as described in claims 8 to 11, wherein the control unit switches the connection state of the main power supply and the connector from the third state to the second state when the connector information indicates that the connector and the device are in the process of being switched from connected to disconnected.

13. A power supply device as described in Claim 12, wherein the control unit switches the connection state between the main power supply and the connector from the third state to the second state, and then switches from the second state to the first state after a predetermined time has elapsed.

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