Power supply device

Abstract

In a power supply unit that allows for easy attachment and detachment of equipment via connectors, this invention suppresses excessive current flow to the power supply unit when connecting it to equipment, regardless of whether the equipment is faulty or its configuration. [Solution] The system 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. The control unit 150 switches the connection state to one of three states: 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 a resistor 141.

Description

[Technical Field]

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

[0002] When connecting a power supply to equipment, an excessive current (so-called inrush current) may flow when the power is turned on. This can occur, for example, if the equipment is equipped with large-capacity smoothing capacitors or decoupling capacitors, as current flows to charge these capacitors first when the power is turned on. To suppress the occurrence of problems caused by such inrush currents, current-limiting means (e.g., current-limiting circuits) may be provided to limit the current supplied to the equipment.

[0003] Patent Document 1 discloses a DC / DC converter comprising a DC / DC converter unit that converts DC voltage and a current limiting unit connected in series to the input side of the DC / DC converter unit, wherein the current limiting unit is configured to operate for a predetermined period of time from the time of power-on, thereby limiting the inrush current at the time of power-on to a predetermined value or less.

[0004] Incidentally, when supplying DC power to equipment, there is little need to install large-capacity capacitors in the equipment. Therefore, in DC power supply, current limiting measures are usually not provided in the power supply unit or the equipment connected to the power supply unit. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2001-238434 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, when there is a failure in the equipment connected to the power supply device, or depending on the configuration of the equipment, excessive current may flow through the power supply device when connecting the power supply device and the equipment, resulting in a failure. Therefore, it is required that the power supply device be provided with means capable of suppressing the occurrence of a failure even in such a case. Also, when removing the equipment from the power supply device, if current is flowing from the power supply device to the equipment, discharge may occur when the contact is separated, and problems such as contact welding may occur.

[0007] The present disclosure aims to suppress excessive current from flowing through the power supply device when connecting the power supply device and the equipment, regardless of the presence or absence of a failure in the equipment or its configuration, in a power supply device where the equipment can be easily attached and detached by a connector. Also, the present disclosure aims to suppress the occurrence of problems due to current flowing when removing the equipment from the 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 capable of supplying power without power conversion from the main power supply, and a control unit for switching the connection state between the main power supply and the connectors. The control unit switches the connection state to any one of 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 passing through the resistor. In this case, it is possible to suppress excessive current from flowing through the power supply device when connecting the power supply device and the equipment, regardless of the presence or absence of a failure in the equipment or its configuration. Here, it further includes acquisition means for acquiring information regarding the necessity of the current limiting operation by the resistor. When the information indicates that the current limiting operation by the resistor is unnecessary, the control unit switches the connection state so that the maintenance time of the second state is shorter than when the information indicates that the current limiting operation by the resistor is necessary. 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. In this case, information regarding the necessity of current limiting operation can be obtained in advance without having to perform a process to detect information when power is supplied to the device. Furthermore, the acquisition means obtains the voltage of the connector in the first state before changing from the first state to the second state as the first voltage (v c1 (0)) and the voltage of the connector when the first time (Δt) has elapsed since the change from the first state to the second state is defined as the second voltage (v) c1 Let (Δt) be the voltage of the connector when a second time (2Δt), which is twice the first time, has elapsed since the change from the first state to the second state, be the third voltage (v c1 When (2Δt)) is assumed, the information is determined based on the ratio of the first voltage difference (Δv1) between the first voltage and the second voltage and 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 the connector when power supply to the equipment is started. The device further comprises two or more first current-limiting circuits and two or more first switches, each of the two or more first current-limiting circuits comprising a resistor and a second switch connected in parallel to the resistor, with 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 a first state in which the main power supply and the connector are not connected, turns on the first switch connected to the connector and turns off the second switch of the first current-limiting circuit connected to the first switch in a second state in which the main power supply and the connector are connected via the resistor, and turns on the first switch connected to the connector and turns on the second switch of the first current-limiting circuit connected to the first switch in a 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 suppress excessive current flowing through the power supply when connecting it to the equipment, regardless of whether the equipment is faulty or its configuration. The control unit further comprises two or more switch circuits, each of which includes a third switch with 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 with one end connected to the other end of the resistor, and the other end connected to the connector, wherein in the first state where the main power supply and the connector are not connected, the control unit turns off the third switch connected to the connector and turns off the fourth switch connected to the connector; in the second state where 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 where 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 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 suppress excessive current flowing through the power supply when connecting it to the equipment, regardless of whether the equipment is faulty or its configuration. The device further comprises a second current-limiting circuit and two or more fifth switches, the second current-limiting circuit comprising a resistor and a sixth switch connected in parallel to the resistor, one end of which is connected to the output of the main power supply and the other end of which is connected to the connector via the fifth switch, and the control unit turns off the fifth switch connected to the connector in the first state in which the main power supply and the connector are not connected, turns on the fifth switch connected to the connector and turns off the sixth switch in the second state in which the main power supply and the connector are connected via the resistor, and turns on the fifth switch connected to the connector and turns 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 switching the fifth and sixth switches on and off to control the connection state between the main power supply and the connector, it is possible to suppress excessive current flowing to the power supply when connecting the power supply to the equipment, regardless of whether there is a malfunction in the equipment or the configuration. Furthermore, the device is equipped with a sensor for detecting the voltage or current of the connector. The control unit, when the connection state is the second state, detects whether the terminals of the connector are short-circuited based on the information from the sensor. The control unit switches the connection state from the first state to the second state and maintains the second state until the detection of whether the terminals of the connector are short-circuited is completed. If it detects that the terminals of the connector are short-circuited, it switches the connection state back to the first state. In this case, the occurrence of a malfunction in the power supply can be suppressed by stopping the power supply when the terminals of the connector are short-circuited. Furthermore, the power supply device of this disclosure further includes connector information acquisition means for acquiring connector information, which is information relating to the connection state between the connector and the device, and the control unit switches to one of the first state, the second state, or the third state, which is the connection state between the main power supply and the connector, according to the connection state between the connector and the device identified by the connector information. In this case, depending on the connection state between the connector and the device, power supply to the device can be restricted if there is a possibility that the device may be removed. Furthermore, if the connector information indicates that the connection between the connector and the device is in the process of being switched from connected to disconnected, the control unit switches the connection state between the main power supply and the connector from the third state to the second state. In this case, it is possible to suppress the occurrence of malfunctions 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, after a predetermined time has elapsed from the third state, switches from the second state to the first state. In this case, after the connection state between the main power supply and the connector switches to the second state, the power supply can be stopped after a predetermined time has elapsed, regardless of the connection state between the connector and the equipment. Furthermore, the connector is equipped with 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 connector information, and the control unit sets the connection state between the main power supply and the connector to the third state if the state of the locking mechanism identified by the connector information is locked, and sets the connection state between the main power supply and the connector to the second state if the state of the locking mechanism identified by the connector information is unlocked. In this case, depending on the state of the locking mechanism, power supply to the device can be restricted if there is a possibility that the device may be removed. Furthermore, the connector is equipped with 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 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 identified by the connector information transitions from a locked state to an unlocked state. In this case, depending on the determination of the connection state between the connector and the device based on the state of the locking mechanism, it is possible to suppress the occurrence of malfunctions caused by current flowing when the device is removed from the connector. 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. The connector information acquisition means acquires information as connector information indicating whether or not the contacts between the connector and the device are in contact. The control unit sets the connection state between the main power supply and the connector to the third state if 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 if the connector information indicates that the contacts between the connector and the device are not in contact. In this case, the power supply to the device can be restricted depending on the contact state at the contacts if there is a possibility that the device may be removed. Furthermore, the connector and the device are provided with contacts that make contact when the connector and the device are connected, separate from the power supply. The connector information acquisition means acquires information as connector information indicating whether the contacts between the connector and the device are in contact or not. 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 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, the determination of the connection state between the connector and the device based on the contact state at the contacts can suppress the occurrence of malfunctions caused by current flowing when the device is removed from the connector. Furthermore, the power supply device of the present disclosure comprises 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 the power supply connection state, which is the connection state between the main power supply and the connector, and connector information acquisition means that acquires connector information, which is information relating to the connection state between the connector and the equipment. The control unit switches the power supply connection state to one of the following states, depending on the equipment 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, and a third state in which the main power supply and the connector are connected without the resistor. In this case, it is possible to suppress the occurrence of malfunctions caused by current flowing when the equipment is removed from the connector. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows the configuration of the power supply according to the first embodiment. [Figure 2] This diagram shows the correspondence between the first to third states and the ON / OFF states of the load switch and current limiting circuit switch. [Figure 3] This figure shows the waveforms of the current and voltage at the connector when power supply begins. [Figure 4] This diagram shows the criteria for determining whether or not there is a short-circuit fault in an external device connected to the connector. [Figure 5] This diagram shows an example configuration where the external equipment connected to the power supply does not have a current-limiting mechanism. [Figure 6] This diagram shows an example configuration where an external device connected to the power supply has a current-limiting mechanism. [Figure 7] This figure shows the waveforms of the current and voltage at the connector when power is first supplied to an external device that does not have a current-limiting circuit. [Figure 8] This figure shows the waveforms of the current and voltage at the connector when power is supplied to an external device with a current-limiting circuit. [Figure 9]This figure shows the current and voltage waveforms at a connector when there is residual charge on a capacitor in an external device that does not have a current-limiting circuit. [Figure 10] This figure shows the current and voltage waveforms at a connector when there is residual charge on a capacitor in an external device with a current-limiting circuit. [Figure 11] This diagram shows how to select the connection status between the main power supply and the connector. Figure 11(A) shows the selection based on the power supply command information, and Figure 11(B) shows the selection based on the short-circuit fault detection and the determination of whether current limiting operation is necessary. [Figure 12] This diagram shows the operation when there is no current-limiting circuit in the external equipment and no short-circuit fault. [Figure 13] This diagram shows the operation when an external device has a current-limiting circuit and there is no short-circuit fault. [Figure 14] This diagram shows the operation when there is a short-circuit fault in an external device. [Figure 15] This diagram shows other operations when there is no current-limiting circuit in the external equipment and no short-circuit fault. [Figure 16] This diagram shows other operations when the external device has a current-limiting circuit and there is no short-circuit fault. [Figure 17] This figure shows the configuration of the power supply according to the second embodiment. [Figure 18] This diagram shows the correspondence between the first to third states and the ON / OFF states of the load switch and current limiting circuit switch. [Figure 19] This figure shows an example of the operation for detecting short-circuit faults in connected external devices and determining whether or not the external devices have a current-limiting circuit for multiple connectors. [Figure 20] This figure shows another example of the operation of detecting short-circuit faults in connected external devices and determining whether or not the external devices have a current-limiting circuit for multiple connectors. [Figure 21] This figure shows another example of the operation of detecting short-circuit faults in connected external devices and determining whether or not the external devices have a current-limiting circuit for multiple connectors. [Figure 22]This figure shows another example of the operation of detecting short-circuit faults in connected external devices and determining whether or not the external devices have a current-limiting circuit for multiple connectors. [Figure 23] This figure shows an example configuration in which the voltage detection means is standardized in the power supply device of the second embodiment. [Figure 24] This figure shows the current waveform and voltage waveform of the connector in response to switch control at the start of power supply in the configuration shown in Figure 23. [Figure 25] This figure shows the configuration of the power supply according to the third embodiment. [Figure 26] This diagram shows the correspondence between the first to third states and the ON / OFF states of the load switch and current limiting circuit switch. [Figure 27] This diagram shows an example of an operation that determines whether or not an external device connected to multiple connectors has a current-limiting circuit. [Figure 28] This figure shows an example of the operation to start supplying power to an external device. [Figure 29] This figure shows another example of operation in which power is supplied to an external device. [Figure 30] This figure shows another example of operation in which power is supplied to an external device. [Figure 31] This diagram shows the operation of the power supply unit when the contacts are separated. [Figure 32] This diagram shows the relationship between the locking state of the locking mechanism on the connector and the control of the power supply unit. [Figure 33] Figure 33(A) shows an example of the socket and plug configuration in Specific Example 2. Figure 33(B) shows the socket and plug fully attached, Figure 33(C) shows the non-powered contacts disconnected, and Figure 33(C) shows the plug removed from the socket. [Figure 34] This diagram shows the relationship between the connection status of the connector to the external device and the control of the power supply unit. [Modes for carrying out the invention]

[0010] Embodiments of this disclosure will be described in detail below with reference to the attached drawings. The power supply unit in this disclosure includes a plurality of connectors, and power is supplied by connecting equipment to each of these connectors. Hereinafter, equipment provided separately from the power supply unit and connected to the connectors will be referred to as external equipment. External equipment is easily attached and detached because it is connected via connectors. The power supply unit has a current-limiting circuit that limits the current supplied to the external equipment. Hereinafter, power supply units according to the first to third embodiments will be presented and described according to the configuration of this current-limiting circuit.

[0011] 〇First Embodiment <Power supply unit configuration> Figure 1 shows the configuration of a power supply according to the first embodiment. The power supply 100 comprises 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, load switches 130, and current limiting circuits 140 are individually corresponding pairs, and each pair of connectors 120, load switches 130, and 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 supplies DC power to the connector 120 via the load switch 130 in each of the above sets. No power conversion circuit is provided between the main power supply 110 and the connector 120. The main power supply 110 may also receive power from an external power source, perform power conversion, and output it to the connector 120. Examples of external power sources that supply power to the main power supply 110 include grid power, solar cells, and storage batteries. A capacitor 111 is provided at the output of the main power supply 110.

[0013] In the multiple connectors 120, an external device as a load can be detachably connected to each connector 120. When an external device is connected to a connector 120, the power supply unit 100 can supply power to the external device via the connector 120. In the multiple load switches 130, each load switch 130 switches between supplying power (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 current-limiting circuit 140 in 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 comprises 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 the 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 an example of a second switch.

[0015] The control unit 150 controls each of the multiple load switches 130 and 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 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, from the first to the third state. The control unit 150 is implemented, for example, by a memory that stores a program and a processor that executes the program stored in the memory.

[0016] Figure 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 Figure 2, the first state is when the main power supply 110 and the connector 120 are not connected (disconnected state). In the first state, the load switch 130 is OFF. Since 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 determined.

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

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

[0019] <Waveforms of current and voltage at connector 120 at the start of power supply> Figure 3 shows the current and voltage waveforms of connector 120 at the start of power supply. Figure 3 shows the changes in the state of one set of connector 120, load switch 130, and current limiting circuit 140 at the start of power supply. Specifically, it shows the changes in the state of the current limiting circuit switch 142 and load switch 130, and the changes in the connection state between the main power supply 110 and connector 120 (labeled "current limiting circuit of power supply unit" in the figure). It also shows the current and voltage waveforms when there is a short-circuit fault in the external device connected to connector 120, and when the external device connected to connector 120 is functioning normally.

[0020] As shown in Figure 3, in the initial state, the current limiting circuit switch 142 and the load switch 130 of the current limiting circuit 140 are OFF. Since 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 (disconnected). At this time, the current in the connector 120 is 0 [A] (amperes) and the voltage is 0 [V] (volts).

[0021] At the start of power supply, the control unit 150 of the power supply unit 100 first turns on the load switch 130, and then turns on the current limiting circuit switch 142. Let t1 be the timing when the load switch 130 turns on, and t2 be the timing when the current limiting circuit switch 142 turns on. In this way, 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 the second state (current limiting). From t2 onwards, both the current limiting circuit switch 142 and the load switch 130 are ON, so the connection state between the main power supply 110 and the connector 120 is the third state (direct connection).

[0022] If the external device connected to connector 120 is functioning correctly, the current in connector 120 will jump when the load switch 130 is turned ON at t1, and then decay exponentially. Then, when the current limiting circuit switch 142 is turned ON at t2, the current will jump slightly before returning to 0[A] and reaching a steady state.

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

[0024] If there is a short-circuit fault in the external device connected to connector 120, the current in connector 120 will jump when the load switch 130 is turned ON at t1, and this state will be maintained. Therefore, the current value that jumped at 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. In FIG. 4, 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 is shown.

[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 thThis is a threshold voltage value that is pre-set as a criterion for determining whether or not there is a short-circuit fault in the external device connected to connector 120.

[0029] Another process involves the voltage value v of connector 120. c1 One example of this process is to detect the load switch 130 at regular intervals and measure the elapsed time t from the point in time (t1) when the load switch 130 was turned ON. In this process, t≦T th v c1 ≧v th If this is true, the external device connected to connector 120 is determined to be functioning correctly. Also, 0≦t≦T th always v c1 <v th If this occurs, the external device connected to connector 120 is determined to be abnormal (has a short circuit fault).

[0030] Another process involves time T from the moment the load switch 130 is turned ON (t1). th Current value i of connector 120 after elapsed time c1 One example of a process is to detect i. c1 ≤i th Therefore, the external device connected to connector 120 is determined to be normal. Also, i c1 >i th Therefore, the external device connected to connector 120 is determined to be abnormal (short circuit fault). Here, i th This is a threshold value of current that is pre-set as a criterion for determining whether or not there is a short-circuit fault in the external device connected to connector 120.

[0031] Another process involves the current value i of connector 120. c1 One example of this process is to detect the load switch 130 at regular intervals and measure the elapsed time t from the point in time (t1) when the load switch 130 was turned ON. In this process, t≦T th de i c1 ≤i th If this is true, the external device connected to connector 120 is determined to be functioning correctly. Also, 0≦t≦T th always i c1 >i thIf this occurs, the external device connected to connector 120 is determined to be abnormal (has a short circuit fault).

[0032] <Determining whether current limiting action is necessary> Next, we will explain how to determine whether or not current limiting operation is necessary in the power supply unit 100. Various external devices can be easily connected to the power supply unit 100 via the connector 120. External devices connected to the connector 120 include those that have current limiting means and those that do not. If the external device has current limiting means, current limiting operation in the power supply unit 100 is unnecessary, and it is desirable to shorten the current limiting operation time and immediately connect the main power supply 110 and the connector 120 directly. Also, even if the external device does not have current limiting means, if a large-capacity capacitor is not provided, current limiting operation in the power supply unit 100 is unnecessary, and it is desirable to shorten the current limiting operation time and immediately connect the main power supply 110 and the connector 120 directly. The method for determining whether or not current limiting operation is necessary in the power supply unit 100 will be explained below.

[0033] Figure 5 shows an example configuration where the external device connected to the power supply unit 100 does not have a current-limiting means. Figure 6 shows an example configuration where the external device connected to the power supply unit 100 does have a current-limiting means.

[0034] The external device 200 shown in Figure 5 has a circuit 210 and is connected to the connector 120 of the power supply unit 100 via a connector 201. A capacitor 211 is provided at the input of the circuit 210.

[0035] The external device 200 shown in Figure 6 has a circuit 210 and a current-limiting circuit 220, and is connected to the connector 120 of the power supply 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 connected in parallel with the resistor 221. The current-limiting circuit 220 is an example of a current-limiting means for the external device 200.

[0036] <Detection of the current limiting circuit of external device 200 based on the current and voltage waveforms of connector 120> Figure 7 shows the current and voltage waveforms of the connector 120 at the start of power supply to an external device 200 without a current-limiting circuit 220. Figure 8 shows the current and voltage waveforms of the connector 120 at the start of power supply to an external device 200 with a current-limiting circuit 220. Figures 7 and 8 show the changes in the state of a set of connector 120, load switch 130, and current-limiting circuit 140 at the start of power supply. Specifically, the changes in the state of the current-limiting circuit switch 142 and the load switch 130, and the changes in the connection state between the main power supply 110 and the connector 120 (labeled "current-limiting circuit of the power supply unit" in the figures) are shown. Figures 7 and 8 also show the current and voltage waveforms when the external device 200 is connected to the connector 120 and power supply is started.

[0037] Figure 8 further shows the state change of the switch 222 of the current limiting circuit 220 in the external device 200. Switch 222 is initially OFF, and turns ON after a certain period of time when power supply to the external device 200 begins. Let t3 be the timing when switch 222 turns ON.

[0038] The current and voltage waveforms shown in Figure 7 are similar to those shown in Figure 3 when the external device 200 is functioning correctly. Therefore, the current in connector 120 jumps sharply at t1 and then decays exponentially. Then, at t2, the current jumps slightly before returning to 0[A] and reaching a steady state. The voltage in connector 120 gradually increases after t1, matching the output voltage V0 of the main power supply 110 at t2 and reaching a steady state.

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

[0040] If the external device 200 has a 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 unit 100 and the resistor 221 of the current-limiting circuit 220 in the external device 200. Therefore, the voltage at 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. As a result, the behavior of the voltage at the connector 120 will be different from the behavior shown in Figure 7.

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

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

[0043] In Figures 7 and 8, Δv1 and Δv2 are calculated from the voltage at connector 120 in the section from t1 to t2. Here, Δv1 is the connector voltage v just before the load switch 130 is turned ON. c1 (0) and the connector voltage v after time Δt has elapsed since the load switch 130 was turned ON. c1This is the difference from (Δt). Therefore, Δv1 = v c1 (Δt)-v c1 (0)

[0044] Furthermore, Δv2 is the voltage at connector 120 (hereinafter referred to as "connector voltage") after time Δt has elapsed since the load switch 130 was turned ON. c1 (Δt) and the connector voltage v after time 2Δt has elapsed since the load switch 130 was turned ON. c1 This is the difference from (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 of the external device 200 is determined by the following equation (Equation 1).

number

[0046] In the above equation (Equation 1), Δt is the interval of time for detecting the connector voltage. th This is the judgment threshold. th This can be set as appropriate, 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") can be set to C th If the resistance value of the resistor 141 of the current limiting circuit 140 in the power supply unit 100 is R, then for example T th =C th It may also be set to R. Here, the current limiting operation by the current limiting circuit 140 in the power supply 100 is necessary when the capacitor capacity of the external equipment 200 is relatively large. Here, the lower limit (threshold) of the capacitor capacity for which such current limiting operation by the current limiting circuit 140 is necessary is set to C. th That is what they say.

[0047] If equation (Equation 1) above holds true, 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 100 is necessary. On the other hand, if equation (Equation 1) above does not hold true, 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 100 is unnecessary.

[0048] Note that the connector voltage v c1 When detecting the voltage and determining whether a current-limiting operation is necessary 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 of the external device 200 connected to the connector 120 (connector voltage) in both cases, whether the load switch 130 is ON or OFF.

[0049] External devices 200 may have a connector voltage greater than 0[V] even when the load switch 130 of the power supply 100 is OFF, for example, due to residual charge in the internal capacitor 211. In such cases, the connector voltage v when the load switch 130 is OFF is... c1 If (0) is unknown, the value of Δv1 above may be incorrect, and the determination of whether or not current limiting operation is necessary for the external device 200 may be incorrect. 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 not 0[V], it is possible to appropriately determine whether or not current limiting operation of the external device 200 is necessary.

[0050] <Current and voltage waveforms when there is residual charge on capacitor 211 of external device 200> Next, we will describe 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 when the load switch 130 of the power supply unit 100 is OFF.

[0051] Figure 9 shows the current and voltage waveforms of the connector 120 when there is residual charge on the capacitor 211 in an external device 200 without a current-limiting circuit 220. Figure 10 shows the current and voltage waveforms of the connector 120 when there is residual charge on the capacitor 211 in an external device 200 with a current-limiting circuit 220. Figures 9 and 10 show the changes in state at the start of power supply in a set of connector 120, load switch 130, and current-limiting circuit 140. Specifically, the changes in state of the current-limiting circuit switch 142 and the load switch 130, and the changes in the connection state between the main power supply 110 and the connector 120 (labeled "current-limiting circuit of the power supply unit" in the figures) are shown. Furthermore, Figure 10 shows the changes in state of switch 222 of the current-limiting circuit 220 in the external device 200. Also, Figures 9 and 10 show the current and voltage waveforms when the external device 200 is connected to the connector 120 and power supply is started.

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

[0053] <Derivation of equation (Equation 1)> Here, we will explain an example of how to derive equation (Equation 1), which was used to determine whether or not the external device 200 has a current-limiting circuit 220. The step response of the RC circuit is expressed by the following equation (Equation 2).

number

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

number

[0055] Next, we derive a relational expression (Equation 1) that determines whether the conditions "the external device 200 does not have a current-limiting circuit 220" and "the input capacitor 211 of the external device 200 has a large capacitance" are met. The time constant T = R·C in the expression is, based on these conditions, T ≥ T th =R·C th This is the result. Note that C th R is the lower limit of the capacitor capacitance of the external device 200 that requires the current-limiting circuit 220. R is the resistance value of resistor 221 of the current-limiting circuit 220 of the external device 200. Therefore, in equation (Equation 3), T≧T th Substituting this into the equation yields the inequality (Mathematics 1).

[0056] <Method for controlling the connection status between the main power supply 110 and the connector 120> Next, the method for controlling the connection state (first state to third state) between the main power supply 110 and the connector 120 in the power supply unit 100 will be described. The control unit 150 of the power supply unit 100 selects whether to set the connection state between the main power supply 110 and the connector 120 to the first state (shut-off), 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 present (c) Necessity of current-limiting operation: unknown / necessary / no

[0057] Here, "power supply command" is a command to supply power to the connector 120 or not. "short-circuit fault detection" is information indicating the result of detecting a short-circuit fault in the external device 200 connected to the connector 120. "current limiting operation requirement" is information indicating the result of the determination of whether or not current limiting operation by the current limiting circuit 140 is required. Note that "unknown" in the information in (b) and (c) means before the determination process or during the determination process. The control unit 150 is an example of an acquisition means for acquiring this information.

[0058] Figure 11 is a diagram showing the method for selecting the connection state between the main power supply 110 and the connector 120. Figure 11(A) shows the selection based on the information of the power supply command. Figure 11(B) shows the selection based on the results of the short-circuit fault detection and the determination of whether or not current limiting operation is required. For example, if there is no power supply command, the first state (shut-off) is selected (see Figure 11(A)). If there is a power supply command, one of the following is selected: the first state (shut-off), the second state (current limiting), or the third state (direct connection) depending on the combination of the determination result of the short-circuit fault detection and the determination result of whether or not current limiting operation is required (see Figure 11(B)). Note that in Figure 11(B), the item "Current limiting operation required: required" has sub-items "Current limiting operation not completed" and "Current limiting operation completed". Here, the control unit 150 determines "Current limiting operation completed" if the predetermined conditions are met in the second state, and determines "Current limiting operation not completed" if the conditions are not met. Furthermore, the third state is defined as "current limiting operation completed," and the first state as "current limiting operation not completed." Examples of predetermined conditions include "duration of the second state ≥ predetermined value" and "connector voltage ≥ threshold."

[0059] Next, the control unit 150 of the power supply unit 100 controls the ON / OFF state of the load switch 130 and the current limiting circuit switch 142 according to the correspondence shown in Figure 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] <Determination of the connection status between the main power supply 110 and the connector 120> Referring to Figures 12 to 16, the process by which the control unit 150 determines the connection status between the main power supply 110 and the connector 120 will be explained. In the following explanation, the necessity of current limiting operation by the current limiting circuit 140 will be replaced with the presence or absence of a current limiting circuit 220 in the external device 200. Therefore, "Current limiting operation necessity: necessary" in Figure 11(B) corresponds to the absence of a current limiting circuit 220 in the external device 200. Also, "Current limiting operation necessity: not necessary" in Figure 11(B) corresponds to the presence of a current limiting circuit 220 in the external device 200. Note that even in configurations where current limiting operation by the current limiting circuit 140 of the power supply unit 100 is unnecessary, such as when the external device 200 does not have a large capacity capacitor, it will be explained as if the external device 200 has a current limiting circuit 220.

[0061] This section describes the control methods for cases based on the presence or absence of a current-limiting circuit 220 in the external device 200 and the presence or absence of a short-circuit fault, as well as the control methods for cases where the presence or absence of a current-limiting circuit 220 in the external device 200 is known in advance. Figures 12 to 16 show the changes in the connection state between the main power supply 110 and the connector 120 (labeled "current-limiting circuit of the power supply unit" in the figures), the changes in the state of the current-limiting circuit switch 142 and the load switch 130, the current waveform and voltage waveform, the determination result of short-circuit fault detection, and the determination result of the presence or absence of a current-limiting circuit 220 in the external device 200, respectively. Furthermore, regarding 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) as "2 (current-limiting)", and the third state (direct connection) as "3 (direct connection)".

[0062] Figure 12 shows the operation when the external device 200 does not have a current-limiting circuit 220 and there is no short-circuit fault. In Figure 12, in the first state (shutdown) where 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 whether a short-circuit fault has been detected and whether the external device 200 has a current-limiting circuit 220 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), when the load switch 130 is ON, the current and voltage at the connector 120 show the waveform pattern described with reference to Figure 7. Then, the short-circuit fault detection process and the process of determining the presence or absence of the current limiting circuit 220 are started. In Figure 12, in the second state (current limiting), the current jumps up once and then decays, and the voltage gradually increases, so it is determined that there is no short-circuit fault in the external device 200. Also, from the way the voltage rises, it is determined that the external device 200 does not have a current limiting circuit 220.

[0064] Based on the above determination results, in the example of Figure 12, the external device 200 does not have a current-limiting circuit 220, so current-limiting operation in the power supply unit 100 is required. Therefore, even after the determination process is completed, the current-limiting circuit switch 142 remains in the OFF state until the predetermined conditions explained with reference to Figure 11(B) are met, and the second state (current-limiting) continues. After this, when the predetermined conditions are 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] Figure 13 shows the operation when the external device 200 has a current-limiting circuit 220 and there is no short-circuit fault. In Figure 13, in the first state (shutdown) where 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 whether a short-circuit fault has been detected and whether the external device 200 has a current-limiting circuit 220 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), when the load switch 130 is ON, the current and voltage at the connector 120 show the waveform pattern described with reference to Figure 8. Then, the short-circuit fault detection process and the process for determining the presence or absence of the current limiting circuit 220 are started. In Figure 13, in the second state (current limiting), the current jumps up once and then decays, and the voltage gradually increases, so it is determined that there is no short-circuit fault in the external device 200. Also, based on the way the voltage rises, it is determined that the external device 200 has a current limiting circuit 220.

[0067] From the above determination results, in the example of Figure 13, since the external device 200 has a current-limiting circuit 220, current-limiting operation in the power supply unit 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 a current-limiting circuit 220 (Figure 13), the period of the second state (current-limiting) can be shortened compared to when it does not have one (Figure 12).

[0068] Figure 14 shows the operation when there is a short-circuit fault in the external device 200. In Figure 14, in the first state (shutdown) where 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 detection of the short-circuit fault and the determination of whether or not there is a 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), when the load switch 130 is ON, the current and voltage at the connector 120 show waveform patterns similar to those of the waveform when there is a short-circuit fault in the external device 200, as explained with reference to Figure 3. Then, the short-circuit fault detection process and the process of determining the presence or absence of the current limiting circuit 220 are started. In Figure 14, in the second state (current limiting), the current remains elevated, and the voltage remains at 0[V] without rising. Therefore, it is determined that there is a short-circuit fault in the external device 200.

[0070] Since a short-circuit fault was detected 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 (disconnected). The process of determining the presence or absence of the current limiting circuit 220 is also completed, and the presence or absence of the current limiting circuit 220 becomes unknown.

[0071] Figure 15 shows other operations when the external device 200 does not have a current-limiting circuit 220 and there is no short-circuit fault. In Figure 15, it is assumed that the control unit 150 of the power supply unit 100 has acquired information indicating that the external device 200 does not have a current-limiting circuit 220. Such cases include, for example, the second or subsequent power supply after connecting the first external device 200, where the determination result from the previous power supply is stored in the memory of the control unit 150. Another case is when the power supply unit 100 has a configuration that allows it to communicate with the external device 200, and the control unit 150 receives information from the external device 200 regarding the presence or absence of a current-limiting circuit 220.

[0072] In Figure 15, in the first state (interruption) where 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 short-circuit fault detection has not yet been determined. On the other hand, based on the information obtained above, 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), when the load switch 130 is ON, the current and voltage at the connector 120 show the waveform pattern described with reference to Figure 7. Then, the short-circuit fault detection process is started. In Figure 15, in the second state (current limiting), the current jumps up once and then decays, and the voltage gradually increases, so it is determined that there is no short-circuit fault in the external device 200.

[0074] In the example shown in Figure 15, since the external device 200 does not have a current-limiting circuit 220, current-limiting operation is required in the power supply unit 100. Therefore, the current-limiting circuit switch 142 remains in the OFF state until the predetermined conditions described with reference to Figure 11(B) are met, and the second state (current-limiting) continues. After this, once the predetermined conditions are 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).

[0075] Figure 16 shows other operations when the external device 200 has a current-limiting circuit 220 and there is no short-circuit fault. In Figure 16, it is assumed that the control unit 150 of the power supply unit 100 acquires information indicating that the external device 200 has a current-limiting circuit 220. Such cases include, for example, the second or subsequent power supply after connecting the first external device 200, where the determination result from the previous power supply is stored in the memory of the control unit 150. Another case is when the power supply unit 100 has a configuration that allows it to communicate with the external device 200, and the control unit 150 receives information from the external device 200 regarding the presence or absence of a current-limiting circuit 220.

[0076] In Figure 16, in the first state (interruption) where 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 short-circuit fault detection has not yet been determined. On the other hand, based on the information obtained above, it has already been identified that the external device 200 has a current limiting circuit 220.

[0077] In the second state (current limiting), when the load switch 130 is ON, the current and voltage at the connector 120 show the waveform pattern described with reference to Figure 7. Then, the short-circuit fault detection process is started. In Figure 16, in the second state (current limiting), the current jumps up once and then decays, and the voltage gradually increases, so it is determined that there is no short-circuit fault in the external device 200.

[0078] In the example shown in Figure 16, since the external device 200 has a current-limiting circuit 220, current-limiting operation in the power supply unit 100 is unnecessary. Therefore, immediately after the short-circuit fault detection determination process is completed, 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). In this way, when the external device 200 has a current-limiting circuit 220 (Figure 16), the period of the second state (current-limiting) can be shortened compared to when it does not have one (Figure 12). Furthermore, when the power supply unit 100 acquires information indicating that the external device 200 has a current-limiting circuit 220 (Figure 16), the period of the second state (current-limiting) can be shortened even further compared to when the presence or absence of the current-limiting circuit 220 is determined (Figure 13).

[0079] 〇Second Embodiment <Power supply unit configuration> Figure 17 shows the configuration of a power supply according to the second embodiment. The power supply 100 comprises 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, load switches 130, and switches 162 are individually corresponding pairs, and each pair of connectors 120, load switches 130, and 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 Figure 1. Therefore, the same reference numerals are used for these parts and their descriptions are omitted. In addition, in the configuration and operation of the power supply unit 100 in the second embodiment, descriptions of those that are the same as those in the power supply unit 100 of the first embodiment, such as the determination procedure for external equipment 200 and the procedure for controlling the connection state between the main power supply 110 and the connector 120, are omitted as appropriate. The load switch 130 in the second embodiment is an example of a third switch.

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

[0082] Figure 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 Figure 18, in the first state (cutoff), 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 turned ON. In other words, it may be prohibited to turn ON two or more current limiting circuit switches 162 simultaneously.

[0083] <Determination of the connection status between the main power supply 110 and the connector 120> Referring to Figures 19 to 22, the process by which the control unit 150 determines the connection status between the main power supply 110 and the connector 120 will be explained. In the examples shown in Figures 19 to 22, except for the specific case shown in Figure 21, power is supplied to each of the multiple connectors 120 in sequence when power supply starts. To show this power supply start order, Figures 19 to 22 show three sets of connectors 120, load switches 130, and current limiting circuit switches 162 in comparison. Each set is distinguished by adding the subscripts 1, 2, and 3 to each component. For example, it is written as current limiting circuit switch 162-1, load switch 130-1, and connector 120-1. Furthermore, each set is identified by these subscripts 1, 2, and 3. For example, the set containing current limiting circuit switch 162-1, load switch 130-1, and connector 120-1 is called the first set, and the set containing current limiting circuit switch 162-2, load switch 130-2, and connector 120-2 is called the second set. If it is not necessary to distinguish between sets of components, they can simply be described as current-limiting circuit switch 162, load switch 130, connector 120, etc.

[0084] Furthermore, in the examples shown in Figures 19 to 22, we will explain the control methods when the presence or absence of the current-limiting circuit 220 in the external device 200 is known in advance, as well as the cases based 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. Figures 19 to 22 show the state changes of the current-limiting circuit switches 162-1, 162-2, 162-3 and the load switches 130-1, 130-2, 130-3, respectively. We will also show the current waveforms and voltage waveforms in connectors 120-1, 120-2, and 120-3, and the changes in the connection state (first state (disconnected), second state (current-limiting), third state (direct connection)) between the main power supply 110 and connectors 120-1, 120-2, and 120-3. In addition, we will show the determination results for short-circuit fault detection in connectors 120-1, 120-2, and 120-3, and the determination results for the presence or absence of the current-limiting circuit 220 in the external device 200. In Figures 19 to 22, the connection status between the main power supply 110 and the connector 120 is indicated as follows: the first state (shut-off) is "1 (shut-off)", the second state (current-limited) is "2 (current-limited)", and the third state (direct connection) is "3 (direct connection)".

[0085] Figure 19 shows an example of the operation of determining whether a short-circuit fault is detected in an external device 200 connected to multiple connectors 120, and whether the external device 200 has a current-limiting circuit 220. In the operation example shown in Figure 19, the determination and control of each set are performed sequentially for each set. Here, we will first explain the operation of each set, and then explain the relationship between the operations of each set.

[0086] First, let's explain the first set. In Figure 19, in the first state (interruption) where the load switch 130-1 and the current limiting circuit switch 162-1 are OFF, the current in connector 120-1 is 0 [A] and the voltage is 0 [V]. In the second state (current limiting) where the current limiting circuit switch 162-1 is ON, the current and voltage in connector 120 show the waveform pattern described with reference to Figure 7. Therefore, it is determined that there is no short-circuit fault in the external device 200 connected to connector 120-1 and that it does not have a current limiting circuit 220. Since the external device 200 does not have a current limiting circuit 220, current limiting operation in the power supply unit 100 is required. Accordingly, the ON state of the current limiting circuit switch 162-1 is maintained until the predetermined conditions described with reference to Figure 11(B) are met, then 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 connector 120 becomes the third state (direct connection).

[0087] Next, we will explain the second set. In Figure 19, in the first state (interruption) where the load switch 130-2 and the current limiting circuit switch 162-2 are OFF, the current in connector 120-2 is 0 [A] and the voltage is 0 [V]. In the second state (current limiting) where the current limiting circuit switch 162-2 is ON, the current and voltage in connector 120 show the waveform pattern described with reference to Figure 8. Therefore, it is determined that there is no short-circuit fault in the external device 200 connected to connector 120-2 and that it has a current limiting circuit 220. Since the external device 200 has a current limiting circuit 220, current limiting operation in the power supply unit 100 is unnecessary. Accordingly, immediately after the determination process is completed, the load switch 130-2 is turned ON and the current limiting circuit switch 162-2 is turned OFF, and the connection state between the main power supply 110 and connector 120 becomes the third state (direct connection).

[0088] Next, we will explain the third set. In Figure 19, in the first state (disconnection), when the load switch 130-3 and the current limiting circuit switch 162-3 are OFF, the current in connector 120-3 is 0[A] and the voltage is 0[V]. In the second state (current limiting), when the current limiting circuit switch 162-3 is ON, the current and voltage in connector 120 show waveform patterns similar to those of the waveform when there is a short-circuit fault in the external device 200, as explained with reference to Figure 3. Therefore, it is determined that there is a short-circuit fault in the external device 200 connected to connector 120-3. Consequently, 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 connector 120 becomes the first state (disconnection).

[0089] In the operation of each of the above sets, in the operation of the first and second sets, when switching from the second state to the third state, the load switch 130 turns ON first, and then the current limiting circuit switch 162 turns OFF. Therefore, in one set, there is a period when both the load switch 130 and the current limiting circuit switch 162 are ON at the same time. This type of control is used to prevent the generation of surge voltage.

[0090] Next, we will explain the timing of the operation of each set. In the example shown in Figure 19, the connection state between the main power supply 110 and the connector 120 is controlled in the order of the first set, the second set, and the third set. Now, let's focus on the timing when the current limiting circuit switches 162-1, 162-2, and 162-3 are turned ON. First, current limiting circuit switch 162-1 is turned OFF, and then current limiting circuit switch 162-2 is turned ON. Also, first current limiting circuit switch 162-2 is turned OFF, and then current limiting circuit switch 162-3 is turned ON. Therefore, multiple current limiting circuit switches 162 belonging to different sets will not be turned ON at the same time.

[0091] Figure 20 shows another example of the operation of determining whether a short-circuit fault is detected in an external device 200 connected to multiple connectors 120, and whether or not the external device 200 has a current-limiting circuit 220. In the operation example shown in Figure 20, the determination and control for each set are performed sequentially for each set, similar to the operation example shown in Figure 19. In the operation example in Figure 20, unlike the operation example in Figure 19, the control unit 150 of the power supply unit 100 has in advance acquired information indicating the short-circuit fault detection result for each set and the determination result regarding the presence or absence of a current-limiting circuit 220 in the external device 200. For example, this may occur when it is the second or subsequent power supply after connecting an external device 200, 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 Figure 20, the operation of the current-limiting circuit switches 162-1, 162-2 and load switches 130-1, 130-2 in each set is generally the same as in the example shown in Figure 19. However, since the control unit 150 holds information on whether or not each external device 200 connected to each connector 120-1, 120-2 has a current-limiting circuit 220, it does not perform a determination of whether or not the current-limiting circuit 220 is present. For this reason, the period of the second state (current limiting) in the second set is shortened compared to the operation shown in Figure 19. In addition, the control unit 150 holds information indicating that there is a short-circuit fault in the external device 200 connected to the connector 120-3 of the third set. For this reason, in the third set, the connection state between the main power supply 110 and the connector 120 remains unchanged in the first state (disconnection), and no determination of a short-circuit fault is made.

[0093] Figure 21 shows another example of the operation of determining whether a short-circuit fault is detected in an external device 200 connected to multiple connectors 120, and whether or not the external device 200 has a current-limiting circuit 220. In the operation example shown in Figure 21, the control unit 150 has previously acquired information indicating the determination result of whether or not a current-limiting circuit 220 is present in each external device 200 connected to each connector 120-1, 120-2, and 120-3. Therefore, it is not necessary to determine whether or not a current-limiting circuit 220 is present at the start of power supply. Thus, in the example shown in Figure 21, unlike the examples shown in Figures 19 and 20, the control of the current-limiting circuit switches 162-1, 162-2, 162-3 and the load switches 130-1, 130-2, 130-3 in each set is performed simultaneously. Here, it is assumed that all external devices 200 have a current-limiting circuit 220.

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

[0095] In the example shown in Figure 21, it is assumed that there are no short-circuit faults in any of the external devices 200. However, if there is a short-circuit fault in any of the external devices 200, in the second state (current limiting), the voltages of all pairs of connectors 120-1, 120-2, and 120-3 will remain at 0[V]. Therefore, 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. Thus, a possible procedure is to first control each pair simultaneously when power is supplied to the external devices 200, and then, if a short-circuit fault is detected in any of the external devices 200, to sequentially control each pair again.

[0096] Figure 22 shows another example of the operation of determining whether a short-circuit fault has occurred in an external device 200 connected to multiple connectors 120, and whether the external device 200 has a current-limiting circuit 220. In the operation example shown in Figure 22, first, the current-limiting circuit switches 162-1, 162-2, 162-3 and load switches 130-1, 130-2, 130-3 of each set are controlled simultaneously. Then, if 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, 162-3 and load switches 130-1, 130-2, 130-3 of each set are controlled sequentially. Through this control, it is determined which external device 200 has the short-circuit fault (in the example shown in Figure 22, the external device 200 connected to connector 120-3 has the short-circuit fault).

[0097] In the above example, the determination of whether or not there is a short-circuit fault in the external device 200 was made based on the change in connector voltage in the second state (current limiting). Alternatively, the determination of whether or not there is a short-circuit fault in the external device 200 could be made based on the change in current in connectors 120-1, 120-2, and 120-3 in the second state (current limiting). As shown in Figure 22, in the second state (current limiting), the current value in connector 120-3, which is connected to the external device 200 with a short-circuit fault, remains elevated. In contrast, the current values ​​in the other connectors 120-1 and 120-2 do not change. Therefore, by making a determination based on the change in current in connectors 120-1, 120-2, and 120-3 in the second state (current limiting), it is possible to immediately identify which of the external devices 200 has a short-circuit fault.

[0098] <Variation> In the second embodiment, the power supply unit 100 has a configuration in which a single resistor 161 is shared in the current-limiting circuit corresponding to each connector 120. In addition, a configuration can be adopted in which the voltage detection means is shared.

[0099] Figure 23 shows an example of a configuration in the power supply unit 100 of the second embodiment in which the voltage detection means are standardized. In the configuration shown in Figure 23, a switch 163 is provided between the resistor 161 and the multiple switches 162. A wire branches off between the switch 163 and the switches 162 and is wired to each of the multiple switches 162. In such a configuration, a voltage detection position may be set between the switch 163 and the branching point. 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] Figure 24 shows the current and voltage waveforms of the connector 120 in response to switch control at the start of power supply in the configuration shown in Figure 23. Figure 24 shows the changes in the state at the start of power supply for one set of connector 120, load switch 130, and current limiting circuit switch 162. Specifically, it shows the changes in the state of current limiting circuit switch 162, current limiting circuit switch 163, and load switch 130, and the changes in the connection state between the main power supply 110 and the connector 120 (labeled "current limiting circuit of the power supply unit" in the figure). In addition, the waveforms of the current and voltage when the external device 200 connected to the connector 120 does not have a current limiting circuit 220 and when it does have a current limiting circuit 220 are shown.

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

[0102] When power supply begins, the current limiting circuit switch 163 is first turned ON, followed by the current limiting circuit switch 162, which brings the connection state between the main power supply 110 and the connector 120 to the second state (current limiting). When the current limiting circuit switch 163 is turned ON, the voltage detected at the voltage detection position described with reference to Figure 23 rises and matches 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 Figure 23 show the waveform pattern described with reference to Figure 9 if the external device 200 does not have a current limiting circuit 220. If the external device 200 does have a current limiting circuit 220, it shows the waveform pattern described with reference to Figure 10.

[0104] 〇Third Embodiment <Power supply unit configuration> Figure 25 shows the configuration of a power supply according to the third embodiment. The power supply 100 comprises 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 load switches 130 are individually corresponding pairs, and each pair of connectors 120 and load switches 130 is connected in parallel to the main power supply 110 via the current limiting circuit 140. Therefore, in the power supply 100 shown in Figure 25, each pair of connectors 120 and load switches 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 Figure 1. Therefore, the same reference numerals are used for these parts and their descriptions are omitted. In addition, in the configuration and operation of the power supply unit 100 in the third embodiment, descriptions of those that are the same as those in the first and second embodiments, such as the determination procedure for external equipment 200 and the procedure for controlling the connection state between the main power supply 110 and the connector 120, are omitted as appropriate. The load switch 130 in the third embodiment is an example of a fifth switch.

[0106] The current-limiting circuit 140 comprises a resistor 141 and a switch 142 connected in parallel with the resistor 141. Hereinafter, the switch 142 provided in the current-limiting circuit 140 may be referred to as the 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] Figure 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 Figure 26, in the first state (cutoff), 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] <Determination of the connection status between the main power supply 110 and the connector 120, and power supply to the external device 200> Referring to Figures 27 to 30, the process by the control unit 150 for determining the connection status between the main power supply 110 and the connector 120, and the power supply to the external device 200 will be explained. 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, a determination is made as to whether there is a short-circuit fault in the external device 200, and power is supplied to the external device 200 according to the determination result. Figure 27 shows the operation of the first stage, and Figures 28 to 30 show the operation of the second stage.

[0109] Figures 27 to 30 show three sets of connectors 120 and load switches 130 for comparison. Each set is distinguished by the subscripts 1, 2, and 3 attached to each component. For example, they are written as load switch 130-1, connector 120-1, etc. These subscripts 1, 2, and 3 also identify each set. For example, the set containing load switch 130-1 and connector 120-1 is called set 1, the set containing load switch 130-2 and connector 120-2 is called set 2, etc. If it is not necessary to distinguish between sets of components, they are simply written as load switch 130, connector 120, etc.

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

[0111] Referring to Figure 27, in the first state (interruption) where 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, load switches 130-1, 130-2, and 130-3 are turned ON in sequence, and it is determined whether or not each of the external devices 200 connected to connectors 120-1, 120-2, and 120-3 has a current-limiting circuit 220. In Figure 27, when load switch 130-1 is turned ON, the connection state of connector 120-1 becomes the second state (current-limiting). In the example shown in Figure 27, the current value of connector 120-1 jumps up and then decays, and the voltage value gradually increases. Here, from the way the voltage value rises, it is determined that the external device 200 connected to connector 120-1 does not have a current-limiting circuit 220. It can also be seen that there is no short-circuit fault in the external device 200 connected to connector 120-1 at this point. After this, load switch 130-1 is turned OFF, and the connection state of connector 120-1 returns to the first state (disconnection).

[0113] Next, when the load switch 130-2 is turned ON, the connection state of connector 120-2 becomes the second state (current limiting). In the example shown in Figure 27, the current value of connector 120-2 jumps up and then decays, and the voltage value gradually increases. Here, from the way the voltage value rises, it is determined that the external device 200 connected to connector 120-2 has a current limiting circuit 220. It can also be seen that there is no short-circuit fault in the external device 200 connected to connector 120-2 at this point. After this, the load switch 130-2 is turned OFF, and the connection state of connector 120-2 returns to the first state (disconnection).

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

[0115] Figure 28 shows an example of the operation to start supplying power to the external device 200. This corresponds to the second stage of the operation described above. Figure 28 also shows the operation performed according to the determination result in Figure 27. At the start of this operation, the control unit 150 of the power supply unit 100 obtains information on the presence or absence of current limiting circuits 220 in each external device 200 connected to connectors 120-1 and 120-2, and that there is a short-circuit fault in the external device 200 connected to connector 120-3.

[0116] Referring to Figure 28, in the first state (interruption) where 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 the presence or absence of the current-limiting circuit 220 in the external device 200 connected to connectors 120-1 and 120-2 is known, load switches 130-1 and 130-2 are turned ON simultaneously. As a result, the connection state of 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 connector 120-3 has a short-circuit fault, load switch 130-3 does not turn ON, and the connection state of connector 120-3 remains the first state (shut-off).

[0118] In the second state (current limiting), the current value of connector 120-1 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 connector 120-1. Also, since it is known that the external device 200 connected to connector 120-1 does not have a current limiting circuit 220, the current limiting circuit switch 142 remains in the OFF state until the predetermined conditions explained with reference to Figure 11(B) are met, and the second state (current limiting) continues. After this, when the predetermined conditions are met, the current limiting circuit switch 142 turns ON, and the connection state of connector 120-1 becomes the third state (direct connection).

[0119] Furthermore, in the second state (current limiting), the current value of 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 connector 120-2. It is also known that the external device 200 connected to 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 unit 100 cannot individually correspond to each connector 120. For this reason, after the determination process for 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 connector 120-2 becomes the first state (disconnected). Then, after the connection state of connector 120-1 becomes the third state (direct connection), the load switch 130-2 is turned ON again, and the connection state of connector 120-2 becomes the third state (direct connection).

[0120] Figure 29 shows another example of operation in which power is supplied to the external devices 200. This corresponds to the second stage of operation described above. Figure 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, the control unit 150 of the power supply unit 100 acquires information on the presence or absence of current limiting circuits 220 in each external device 200 connected to connectors 120-1, 120-2, and 120-3.

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

[0122] Next, since the presence or absence of the current-limiting circuit 220 of the external device 200 connected to connectors 120-1, 120-2, and 120-3 is known, load switches 130-1, 130-2, and 130-3 are turned ON simultaneously. Then, the connection state of connectors 120-1, 120-2, and 120-3 becomes the second state (current-limiting).

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

[0124] Figure 30 shows another example of operation in which power is supplied to the external devices 200. This corresponds to the second stage of operation described above. Figure 30 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 do not have current limiting circuits 220. At the start of this operation, the control unit 150 of the power supply unit 100 acquires information on the presence or absence of current limiting circuits 220 in each external device 200 connected to connectors 120-1, 120-2, and 120-3.

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

[0126] Next, since the presence or absence of the current-limiting circuit 220 of the external device 200 connected to connectors 120-1, 120-2, and 120-3 is known, load switches 130-1, 130-2, and 130-3 are turned ON simultaneously. Then, the connection state of connectors 120-1, 120-2, and 120-3 becomes the second state (current-limiting).

[0127] In the second state (current limiting), the current values ​​in connectors 120-1, 120-2, and 120-3 jump up and then decay, while the voltage values ​​gradually increase. Therefore, it can be seen that there are no short-circuit faults in any of the external devices 200 connected to connectors 120-1, 120-2, and 120-3. Furthermore, since it is known that none of the external devices 200 connected to connectors 120-1, 120-2, and 120-3 have current-limiting circuits 220, after the determination process in the second state (current limiting) is completed, the current-limiting circuit switch 142 remains in the OFF state until the predetermined conditions explained with reference to Figure 11(B) are met, and the second state (current limiting) continues. After this, when the predetermined conditions are met, the current-limiting circuit switch 142 turns ON, and the connection state of connectors 120-1, 120-2, and 120-3 becomes the third state (direct connection).

[0128] 〇Fourth Embodiment In the first to third embodiments, control during connection between the power supply unit 100 and the external device 200 was described. However, even when the external device 200 is disconnected from the power supply unit 100, problems may occur because power is still being supplied to the external device 200 from the power supply unit 100. For example, an arc discharge may occur when the contacts are separated, causing contact welding. Therefore, in the power supply unit 100 according to this disclosure, it is conceivable to suppress the occurrence of the above-mentioned problems by controlling the electrical connection state between the main power supply 110 and the connector 120 when the external device 200 is disconnected from the power supply unit 100. Below, as a fourth embodiment, a power supply unit 100 that controls the connection state between the main power supply 110 and the connector 120 when the contacts are separated will be described.

[0129] <Power supply unit configuration> In the fourth embodiment, the power supply unit 100 only needs to be capable of controlling the connection state between the main power supply 110 and the connector 120 to one of the first, second, or third states, and its specific configuration is not limited. Therefore, the configuration of the power supply unit 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 unit 100, the main power supply 110 provided in the power supply unit 100, the connector 120 and the control unit 150, the external device 200, and the connector 201 of the external device 200 will be denoted by the same reference numerals used in the first to third embodiments.

[0130] In the first to third embodiments, the power supply unit 100 had a configuration with multiple connectors 120, but in the fourth embodiment, the number of connectors 120 is not limited. This is because the problem of the fourth embodiment is to suppress malfunctions that may occur even when an external device 200 is disconnected from the power supply unit 100 using a single connector 120. In the following description, we will assume that the power supply unit 100 has one connector 120.

[0131] In the fourth embodiment, the power supply unit 100 includes connector information acquisition means for acquiring 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 indicates whether the connection state between the connector 120 and the external device 200 is in a first connection state, a second connection state, or a third connection state.

[0132] The first connection state is when connector 120 and external device 200 are connected, and the removal of external device 200 is not anticipated. The second connection state is when connector 120 and external device 200 are connected, but the removal of external device 200 is anticipated. In other words, the second connection state indicates that the connection between connector 120 and external device 200 is in the process of switching from connected to disconnected. The third connection state is when external device 200 has been removed from connector 120 (is not connected).

[0133] The control unit 150 of the power supply unit 100 acquires connector information via a connector information acquisition means. 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 of the control unit 150 when the contacts are separated> Figure 31 shows the operation of the power supply unit 100 when the contacts are separated. Here, it is assumed that the external device 200 is connected to the connector 120 and powered by it in the initial state. 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 status 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 predetermined execution conditions are met. Specifically, for example, the determination is made periodically. Alternatively, the determination may be made when a predetermined event occurs that serves as a trigger for the determination.

[0136] If the S101 decision determines that the mechanical connection state remains in the first connection state (NO in S102), the control unit 150 waits again for the conditions for determining the connection state to be met. On the other hand, if the S101 decision determines 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 suppresses the occurrence of problems such as arc discharge and contact welding that occur when the contacts separate.

[0137] After switching the electrical connection state between the main power supply 110 and the connector 120 to the second state (current limiting), the control unit 150 waits for a predetermined time to elapse (NO in S104). Then, when the predetermined time has elapsed (YES in S104), the control unit 150 switches the electrical connection state between the main power supply 110 and the 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 switch from the third state (direct connection) to the first state (disconnection) in S103, but instead switches 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 is given in S102), the external device 200 is not necessarily immediately disconnected from the connector 120 (becoming the third connection state). For this reason, instead of directly switching from the third state (direct connection) to the first state (disconnection) and stopping the power supply, it switches to the second state (current limiting). By switching to the second state (current limiting), the power supply current is restricted, so even if the external device 200 is disconnected from the connector 120 in this state, the occurrence of malfunctions such as 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 second state (current limiting) in S103, and then switches it to the first state (shut-off) after a predetermined time has elapsed (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 disconnected from the connector 120 as part of a series of operations (becoming the third connection state). For this reason, connector information is not used as the transition condition for moving from the second state (current limiting) to the first state (shut-off), and the elapsed time is used as the transition condition.

[0140] <Specific examples of connector information acquisition methods> The following describes specific examples of connector information acquisition means. The connector information acquisition means acquires connector information that represents the connection status between connector 120 and external device 200. Connector 120 and external device 200 are provided with a configuration for generating connector information. Here, two specific examples of the configuration of the connector information acquisition means are given and explained.

[0141] • Specific example 1 Specific example 1 involves a connector 120 equipped with a locking mechanism that locks the connection between the connector 120 and an external device 200, and acquiring information indicating the state of the locking mechanism as connector information. The structure of the locking mechanism itself is not particularly limited, and various existing locking mechanisms can be used. For example, locking mechanisms using bayonet locks, screw locks, snap-in locks, push-pull locks, latch locks, lever locks, etc., can be employed.

[0142] The locking mechanism is provided with means for acquiring information (hereinafter referred to as "state information") indicating whether it is in a locked state or an unlocked state. The specific configuration of the means for acquiring this state information is not limited as long as it is capable of acquiring the state 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 from the ON / OFF state of this contact may be acquired as state information.

[0143] Figure 32 is a diagram showing the relationship between the locked state of the locking mechanism provided on the connector 120 and the control of the power supply unit 100. The control unit 150 determines the locked state of the locking mechanism based on the status information described above, for example. Then, the control unit 150 determines the connection state between the connector 120 and the external device 200 according to the locked state of the locking mechanism and controls the connection state between the main power supply 110 and the connector 120.

[0144] In the example shown in Figure 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. 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). When 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. 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). The control unit 150 may also set the electrical connection state between the main power supply 110 and the connector 120 to the second state (current limiting) when it 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, and then switch back to the first state (shut-off) after a predetermined time has elapsed.

[0145] Therefore, when the external device 200 is to be disconnected from the connector 120 of the power supply unit 100, the control unit 150 performs 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 disconnected from the connector 120, from which the locking mechanism has been released.

[0146] Furthermore, even when an external device 200 is connected to the connector 120, the connection between the main power supply 110 and the connector 120 may be made based on the state of the locking mechanism. For example, the following control can be considered. When the external device 200 is connected to the connector 120, the locking mechanism is in the released state. Based on the fact that 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. 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 and enters 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 fact that the locking mechanism is 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). Furthermore, 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 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] • Specific example 2 Specific example 2 involves providing the power supply unit 100's connector 120 and the external device 200's connector 201 with contacts (hereinafter referred to as "non-power supply contacts") that make contact when the connector 120 and the external device 200 are connected, separate from the power supply. Information indicating the contact state of the power supply contacts and non-power supply contacts is then acquired as connector information. As an example, consider a configuration in which the power supply unit 100's connector 120 has a socket 300, and the external device 200's connector 201 has a plug 400 that is attached to the socket 300, and both the socket 300 and the plug 400 have non-power supply contacts.

[0148] Figure 33 shows an example configuration of the socket 300 and plug 400 in specific example 2. Figure 33(A) shows the socket 300 and plug 400 fully installed, Figure 33(B) shows the non-powered contacts disconnected, and Figure 33(C) shows the plug 400 removed from the socket 300.

[0149] In the example shown in Figure 33, the plug 400 is provided with a power supply pin 410 for supplying power and an information pin 420 used as a non-power supply contact. The socket 300 is provided with an insertion opening 310 into which the power supply pin 410 is inserted and an insertion opening 320 into which the information pin 420 is inserted. In the example shown in Figure 33, the non-power supply contact is not simply a contact that the plug 400 makes contact with when it is mounted on the socket 300, but rather an information pin 420 that is inserted into the insertion opening 320 of the socket 300. This ensures that the non-power supply contact makes reliable contact when the plug 400 is mounted on the socket 300, and prevents unstable contact of the non-power supply contact.

[0150] In the configuration example shown in Figure 33, the information pin 420 is shorter than the power supply pin 410. Therefore, when removing the plug 400 from the socket 300 (pulling it out), the information pin 420 comes out of the insertion opening 320 before the power supply pin 410 comes out of the insertion opening 310. Referring to Figure 33, as shown in Figure 33(A), when the plug 400 is fully installed in the socket 300, both the power supply pin 410 and the information pin 420 are inserted into the insertion openings 310 and 320, respectively.

[0151] When the plug 400 is removed from the socket 300, as shown in Figure 33(B), the short information pin 420 is removed from the socket 320 before the longer power supply pin 410. In this state, the power supply pin 410 remains in contact, while only the information pin 420, which is a non-power supply contact, becomes non-contact.

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

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

[0154] Figure 34 shows the relationship between the connection state between the connector 120 and the external device 200 and the control of the power supply unit 100. The control unit 150 determines the contact state of the non-power supply contacts based on the contact information described above, for example. Then, the control unit 150 determines the connection state between the connector 120 and the external device 200 according to the contact state of the non-power supply contacts and controls the connection state between the main power supply 110 and the connector 120.

[0155] In the example shown in Figure 34, when the power supply pin 410 and the information pin 420 are in contact with (inserted into) the insertion slots 310 and 320, the control unit 150 determines that the mechanical connection state between the connector 120 and the external device 200 is the first connection 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). Although it is assumed here that the power supply pin 410 and the information pin 420 are in contact with the insertion slots 310 and 320, in reality it is sufficient to determine that the information pin 420 is in contact with the insertion slot. This is because when the short information pin 420 is in contact with the insertion slot 320, the long power supply pin 410 is always in contact with the insertion slot 310.

[0156] Furthermore, if only the power supply pin 410 is in contact with the insertion opening 310 and the information pin 420 is not in contact with the insertion opening 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). If neither the power supply pin 410 nor the information pin 420 is in contact with the insertion openings 310 and 320, the connector 120 and the external device 200 are completely separated, so the control unit 150 controls the electrical connection state between the main power supply 110 and the connector 120 to the first state (disconnection). Furthermore, 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 control the electrical connection state between the main power supply 110 and the connector 120 to the second state (current limiting), and then switch back to the first state (shut-off) after a predetermined time has elapsed. Also, if neither the power supply pin 410 nor the information pin 420 is in contact with the insertion openings 310 and 320, the control unit 150 may control the electrical connection state between the main power supply 110 and the connector 120 to the second state (current limiting).

[0157] Therefore, when the external device 200 is to be removed from the power supply unit 100 while its connector 201 is connected to the power supply unit 120, the control unit 150 performs 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 opening 320 become non-contact, 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 opening 310 become non-contact, and the connector 201 of the external device 200 is removed from the connector 120.

[0158] Furthermore, when an external device 200 is connected to the connector 120, the connection between the main power supply 110 and the connector 120 may also be made based on the contact state between the power supply pin 410 and the information pin 420 and the insertion openings 310 and 320. For example, the following control can be considered. When the plug 400 is attached to the socket 300 to connect the external device 200 to the connector 120, the power supply pin 410 first makes contact with the insertion opening 310. Based on the fact that only the power supply pin 410 is in contact with the insertion opening 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. 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 limit). Next, when the plug 400 is pushed further into the socket 300, the information pin 420 makes contact with the insertion opening 320. The control unit 150 determines that the mechanical connection state between the connector 120 and the external device 200 is a first connection state based on the fact that the power supply pin 410 and the information pin 420 are in contact with the insertion openings 310 and 320. The control unit 150 then controls the electrical connection state between the main power supply 110 and the connector 120 to a third state (direct connection). The control unit 150 may also control the electrical connection state between the main power supply 110 and the connector 120 to a third state (direct connection) based on the fact that the power supply pin 410 and the information pin 420 are in contact with the insertion openings 310 and 320, and a predetermined time has elapsed since the electrical connection state between the main power supply 110 and the connector 120 was controlled to a 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 switches the connection state to one of three states: 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 the resistor 141. In this case, regardless of whether or not there is a malfunction in the equipment connected to the connectors or the configuration of the equipment connected to the connectors, it is possible to suppress the flow of excessive current to the power supply device when connecting the power supply device to the equipment connected to the connectors. The system further includes means for acquiring information regarding the necessity of current-limiting operation by the resistor 141. The control unit 150 switches the connection state such that, when the information indicates that current-limiting operation by the resistor 141 is unnecessary, the time spent maintaining the second state is shorter than when the information indicates that current-limiting operation by the resistor 141 is necessary. In this case, unnecessary current-limiting operation can be suppressed, and the time required from the start of power supply to reaching a 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 having to perform a process to detect information when power is supplied to the device. Furthermore, the acquisition means obtains the voltage of the connector 120 in the first state before changing from the first state to the second state as the first voltage (v c1 (0)) and the voltage of the connector 120 when the first time (Δt) has elapsed since the change from the first state to the second state is defined as the second voltage (v) c1 Let (Δt) be the third voltage (v) when a second time (2Δt), which is twice the first time, has elapsed since the change from the first state to the second state. c1When (2Δt)) is set, the information is determined based on the ratio of the first voltage difference (Δv1) between the first voltage and the second voltage and 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 of the connector 120 when power supply to the equipment is started. Furthermore, the system comprises two or more first current-limiting circuits 140 and two or more first switches 130, each of the two or more first current-limiting circuits 140 comprising a resistor 141 and a second switch 142 connected in parallel to the resistor 141, with 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, in the first state in which the main power supply 110 and the connector 120 are not connected, turns off the first switch 130 connected to the connector 120, and the main power supply 11 In the second state, when the power supply 0 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. In the third state, when 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 switching the first and second switches on and off to control the connection state between the main power supply 110 and the connector 120, it is possible to suppress excessive current flowing to the power supply when connecting the power supply to the equipment connected to the connector, regardless of whether the equipment connected to the connector is faulty or its configuration. Furthermore, the control unit 150 further comprises two or more switch circuits, each of which includes a third switch 130, one end of which is connected to the output of the main power supply 110 and one end of the resistor 161, and the other end of which is connected to the connector 120; and a fourth switch 162, one end of which is connected to the other end of the resistor 161, and the other end of which is 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 the control unit 150 is connected to the connector 120. In the second state, when 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, when 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 switching the third and fourth switches on and off to control the connection state between the main power supply 110 and the connector 120, it is possible to suppress excessive current flowing to the power supply when connecting the power supply to the equipment connected to the connector, regardless of whether the equipment connected to the connector is faulty or its configuration. Furthermore, the control unit 150 further comprises a second current-limiting circuit 140 and two or more fifth switches 130, the second current-limiting circuit 140 comprising a resistor 141 and a sixth switch 142 connected in parallel to the resistor 141, one end of which is connected to the output of the main power supply 110 and the other end of which is connected to the connector 120 via the fifth switch 130, and the control unit 150, in the first state in which the main power supply 110 and the connector 120 are not connected, is connected to the connector 120 In the second state, when 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. In the third state, when 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 switching the fifth and sixth switches on and off to control the connection state between the main power supply 110 and the connector 120, it is possible to suppress excessive current flowing to the power supply when connecting the power supply to the equipment connected to the connector, regardless of whether the equipment connected to the connector is faulty or its configuration. Furthermore, the connector 120 is equipped with a sensor for detecting voltage or current. The control unit 150, when the connection state is the second state, detects whether the terminals of the connector 120 are short-circuited based on the information from the sensor. It then switches the connection state from the first state to the second state and maintains the second state until it has finished detecting whether the terminals of the connector 120 are short-circuited. If it detects that the terminals of the connector 120 are short-circuited, it switches the connection state back to the first state. In this case, by stopping the power supply when the terminals of the connector 120 are short-circuited, the occurrence of failures in the power supply unit can be suppressed. Furthermore, the power supply device 100 of this disclosure further includes connector information acquisition means for acquiring connector information, which is information relating to the connection status between the connector 120 and the external device 200. The control unit 150 switches to one of the following states: the first state, which is the connection status between the main power supply 110 and the connector 120; the second state; or the third state, depending on the connection status between the connector 120 and the external device 200 as identified by the connector information. In this case, depending on the connection status between the connector 120 and the external device 200, power supply to the external device 200 can be restricted if there is a possibility that the external device 200 may be removed. Furthermore, if the connector information indicates that the connection between the connector 120 and the external device 200 is in the process of being switched from connected to disconnected, 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 suppress the occurrence of malfunctions caused by current flowing when the external device 200 is removed from the connector 120. Furthermore, the control unit 150 switches the connection state of the main power supply 110 and the connector 120 from the third state to the second state, and then, after a predetermined time has elapsed from the third state, switches from the second state to the first state. In this case, after the connection state of the main power supply 110 and the connector 120 switches to the second state, the 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 is equipped with 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 connector information. The control unit 150 sets the connection state between the main power supply 110 and the connector 120 to the third state if the state of the locking mechanism identified 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 if the state of the locking mechanism identified by the connector information is unlocked. In this case, depending on the state of the locking mechanism, power supply to the external device 200 can be restricted if there is a possibility that the external device 200 may be removed. Furthermore, the connector 120 is equipped with 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 connector information. When the state of the locking mechanism, as identified by the connector information, transitions from a locked state to an unlocked state, 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, 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, it is possible to suppress the occurrence of malfunctions caused by current flowing when the external device 200 is removed from the connector 120. Furthermore, the connector 120 and the external device 200 are provided with contacts that make contact when the connector 120 and the external device 200 are connected, separate from the power supply. The connector information acquisition means acquires information as connector information indicating whether the contacts of the connector 120 and the external device 200 are in contact. The control unit 150 sets the connection state between the main power supply 110 and the connector 120 to the third state if the connector information indicates that the contacts of 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 if the connector information indicates that the contacts of the connector 120 and the external device 200 are not in contact. In this case, depending on the contact state at the contacts, power supply to the external device 200 can be restricted if there is a possibility that the external device 200 may be removed. Furthermore, the connector 120 and the external device 200 are provided with contacts that make contact when the connector 120 and the external device 200 are connected, separate from the power supply. The connector information acquisition means acquires information as connector information indicating whether the contacts between the connector 120 and the external device 200 are in contact or not. 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, depending on the determination of the connection state between the connector 120 and the external device 200 based on the contact state at the contacts, it is possible to suppress the occurrence of malfunctions caused by current flowing when the external device 200 is removed from the connector 120. Furthermore, 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 the power supply connection state, which is the connection state between the main power supply 110 and the connector 120, and connector information acquisition means that acquires connector information, which is information relating to the connection state of the external device 200, which is the connection state between the connector 120 and the external device 200. The control unit 150 switches the power supply connection state to one of the following states, depending on the connection state of the external device 200 identified by the connector information: 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 suppress the occurrence of malfunctions due to current flowing when the external device 200 is removed from the connector 120.

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

[0161] 100...Power supply unit, 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...Inlet, 320...Inlet, 400...Plug, 410...Power supply pin, 420...Information pin

Claims

1. A main power source capable of supplying DC power, Two or more connectors capable of supplying power from the aforementioned main power supply without power conversion, The system includes a control unit that switches the connection state between the main power supply and the connector, The control unit determines the connection state, 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 following: power supply.

2. The system further includes means for acquiring information regarding whether or not current-limiting operation by the resistor is necessary, The control unit switches the connection state such that, when the information indicates that current limiting by the resistor is unnecessary, the time spent maintaining the second state is shorter than when the information indicates that current limiting by the resistor is necessary. The power supply device according to claim 1.

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

4. The acquisition means is, The voltage of the connector in the first state before changing from the first state to the second state is defined as the first voltage (v c1 (0)) The voltage of the connector at the time when the first time (Δt) has elapsed since the change from the first state to the second state is defined as the second voltage (v c1 (Δt)) The voltage of the connector at the time when a second time (2Δt), which is twice the first time, has elapsed since the change from the first state to the second state, is defined as the third voltage (v c1 When (2Δt) is set, The first voltage difference (Δv) between the first voltage and the second voltage 1 ) and the second voltage difference (Δv) between the second voltage and the third voltage. 2 Based on the ratio of ), the above information is determined. The power supply device according to claim 2.

5. Two or more first current-limiting circuits, It further includes two or more first switches, Each of the two or more of the first current-limiting circuits is The resistor and, The device comprises a second switch connected in parallel to the resistor, One end is 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 according to claim 1.

6. It further includes two or more switch circuits, The aforementioned switch circuit is A third switch, one end of which is connected to the output of the main power supply and one end of the resistor, and the other end of which is connected to the connector, A fourth switch is provided, one end of which is connected to the other end of the resistor, and the other end of which is 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, the third switch connected to the connector is turned off, and the fourth switch connected to the connector is turned on. 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 according to claim 1.

7. The second current-limiting circuit, It further includes two or more fifth switches, The aforementioned second current-limiting circuit is The resistor and, The resistor is connected in parallel with a sixth switch, One end is 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 according to claim 1.

8. The connector is equipped with a sensor that detects the voltage or current of the connector, The control unit, When the connection state is the second state, it is detected whether or not there is a short circuit between the terminals of the connector based on the 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 there is a short circuit between the terminals of the connector is completed. If a short circuit is detected between the terminals of the connector, the connection state is switched to the first state. The power supply device according to claim 1.

9. The system further comprises connector information acquisition means for acquiring connector information, which is information relating to the connection status between the connector and the device. The control unit switches to one of the following states, depending on the connection state between the connector and the device as identified by the connector information: the first state, which is the connection state between the main power supply and the connector; the second state; or the third state. The power supply device according to claim 1.

10. The power supply device according to claim 9, wherein 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 connector information indicates that the connection between the connector and the device is in the process of being switched from connected to disconnected.

11. The power supply device according to claim 10, wherein the control unit switches the connection state of the main power supply and the connector from the third state to the second state, and then, after a predetermined time has elapsed from the third state, switches from the second state to the first state.

12. The connector is equipped with 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 connector information, The control unit, If the state of the locking mechanism identified by the connector information is the locked state, the connection state between the main power supply and the connector is set to the third state. The power supply device according to claim 9, wherein if the state of the locking mechanism identified by the connector information is in the unlocked state, the connection state between the main power supply and the connector is set to the second state.

13. The connector is equipped with 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 connector information, The control unit, The power supply device according to claim 9, wherein when the state of the locking mechanism identified by the connector information transitions from a locked state to an unlocked state, the connection state between the main power supply and the connector is switched from the third state to the second state.

14. The connector and the device are provided with contacts that make contact when the connector and the device are connected, separate from the power supply. The connector information acquisition means acquires information as connector information indicating whether or not the contacts between the connector and the device are in contact. The control unit, If the connector information indicates that the contacts between 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. The power supply device according to claim 9, wherein if the connector information indicates that the contacts between 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.

15. The connector and the device are provided with contacts that make contact when the connector and the device are connected, separate from the power supply. The connector information acquisition means acquires information as connector information indicating whether or not the contacts between the connector and the device are in contact. The control unit, The power supply device according to claim 9, wherein when the connector information indicates that the contacts between the connector and the device transition 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.

16. A main power source capable of supplying DC power, A connector capable of supplying power from the aforementioned main power source without power conversion, A control unit that switches the power connection state, which is the connection state between the main power supply and the connector, The system includes connector information acquisition means for acquiring connector information, which is information relating to the device connection state, which is the connection state between the connector and the device. The control unit, in accordance with the device connection status identified by the connector information, determines the power supply connection status. 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 following: power supply.

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