Electronic device, charging system, charging method and program

Abstract

To detect increase of contact resistance in a connector more securely.SOLUTION: An electronic device 100 includes: a connector 170 connected to an external device 200; a second measurement part 160 which measures an electric current flowing through a secondary battery 141, which is electrically connected to the external device 200 to be supplied with electric power, or a voltage in the connector 170; and a control unit 131 which acquires a charging state of the secondary battery 141 and determines whether an abnormality occurs in a connection state between the external device 200 and the electronic device 100 based on the acquired charging state and a measurement result of the second measurement part 160.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This invention relates to an electronic device , Mitsuru The present invention relates to a charging system, a charging method, and a program. [Background technology]

[0002] Secondary batteries are widely used as power sources for portable electronic devices. Such secondary batteries are often charged by a charging circuit built into the electronic device by connecting an AC (Alternating Current) adapter to the electronic device. In this case, if there is an abnormality such as poor contact in the connector used to connect the AC adapter to the electronic device, charging cannot be performed normally. In order to prevent such charging abnormalities, for example, Patent Document 1 discloses an electronic device that can notify a user of a short circuit abnormality inside the connector during charging. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-8582 A Summary of the Invention [Problem to be solved by the invention]

[0004] The electronic device disclosed in Patent Document 1 detects an abnormality in a connector by comparing the voltage (or current) applied to a load with a predetermined reference threshold value. However, there is only one reference threshold value, and depending on the charging state, there is a problem that the abnormality cannot be detected well.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and provides an electronic device that can more reliably detect an increase in contact resistance in a connector. , Mitsuru The present invention aims to provide a charging system, a charging method, and a program. [Means for solving the problem]

[0006] In order to achieve the above object, an electronic device according to the present invention comprises: A connector for connecting to an external device; A first measurement unit that measures at least a voltage of the secondary battery; The external device is electrically connected to the external device to receive power. The above A second measurement unit that measures at least a current flowing through the secondary battery; A control unit, The control unit is Based on the voltage measured by the first measurement unit, The state of charge of the secondary battery At least one of CC charging state, CV charging state, and charging stop state. Get The measured current and, Acquired The CC charging state, the CV charging state, and the charging stop state at the time of acquiring the charging state. In charging state The current threshold is set according to , By comparing It is determined whether or not an abnormality has occurred in the connection state between the external device and the electronic device. Effect of the Invention

[0007] According to the present invention, an increase in contact resistance in a connector can be detected more reliably. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating an example of the configuration of a charging system according to a first embodiment. [Diagram 2] 4 is a graph showing an example of the relationship between an input voltage, a battery voltage, and a charging current during charging. [Diagram 3] 1 is a graph illustrating a decrease in charging current when contact resistance increases, and a threshold value of the charging current in each charging state. [Figure 4] 4 is a graph showing an example of the relationship between a voltage difference (a difference between an input voltage and a battery voltage) and a charging current. [Diagram 5] 4 is a flowchart of an abnormality determination process according to the first embodiment. [Figure 6] FIG. 13 is a diagram illustrating charging characteristics when charging at a low temperature. [Figure 7] FIG. 11 is a diagram illustrating an example of the configuration of a charging system according to a second embodiment. [Figure 8] 10 is a flowchart of an abnormality determination process according to a second embodiment. [Figure 9] 10 is a flowchart of a voltage control process according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

[0010] (First embodiment) As shown in FIG. 1, a charging system 1000 according to the first embodiment includes an electronic device 100 and an external device 200.

[0011] The external device 200 is an AC adapter that is electrically connected to the electronic device 100 to supply power. The external device 200 supplies power to the electronic device 100 through a connector 220 by inserting a plug of the external device 200 into an outlet. The external device 200 includes an output unit 210 that outputs power to be supplied to the electronic device 100.

[0012] The electronic device 100 is any electronic device that operates on a secondary battery (rechargeable battery), such as a smart watch, an electronic clock, or an electronic dictionary. As shown in FIG. 1, the electronic device 100 includes a control unit 131, a storage unit 132, a notification unit 133, a charging control unit 140, a first measurement unit 150, and a second measurement unit 160, and receives power from an external device 200 through a connector 170. For convenience, FIG. 1 illustrates a charging circuit 120, which is a circuit for charging the secondary battery 141, and a main circuit 110, which is the other circuit, with a distinction between them, but this distinction is not strict. For example, a part of the configuration in the main circuit 110 (e.g., the control unit 131) also controls the charging circuit 120.

[0013] The control unit 131 includes a processor such as a CPU (Central Processing Unit). The control unit 131 controls the electronic device 100 by executing a program stored in the storage unit 132.

[0014] The storage unit 132 includes memories such as a Read Only Memory (ROM) and a Random Access Memory (RAM), and stores the programs executed by the CPU of the control unit 131 and necessary data.

[0015] The notification unit 133 includes an LED (Light Emitting Diode), a liquid crystal display panel, a buzzer, etc., and notifies the user of an abnormality in the connection state between the external device 200 and the electronic device 100, etc.

[0016] The charging control unit 140 includes a charging control IC (Integrated Circuit) and the like, and supplies power obtained from the external device 200 via the connector 170 to the secondary battery 141, and charges the secondary battery 141 using a constant current constant voltage (CCCV) charging method.

[0017] The first measuring unit 150 includes a battery voltage measurement IC (for example, a battery fuel gauge IC) and measures the voltage (battery voltage) of the secondary battery 141. Note that the first measuring unit 150 may measure the current (charging current) flowing through the secondary battery 141 in addition to the voltage of the secondary battery 141.

[0018] The second measuring unit 160 includes an ammeter or a voltmeter, and measures the current flowing through the secondary battery 141 or the voltage (input voltage) at the connector 170. The second measuring unit 160 may include both an ammeter and a voltmeter, and measure both the current flowing through the secondary battery 141 and the voltage at the connector 170.

[0019] 1, the second measuring unit 160 measures the input voltage (voltage monitoring) by measuring the potential difference between the connector 170 and GND (Ground). Also, in FIG. 1, the second measuring unit 160 obtains the value of the current flowing through the secondary battery 141 by measuring the voltage across the resistor 161 for current monitoring, but the method of obtaining the current value is not limited to this. For example, if the first measuring unit 150 also measures the charging current, the second measuring unit 160 may obtain the value of the charging current measured by the first measuring unit 150 as the value of the current flowing through the secondary battery 141.

[0020] The secondary battery 141 is a rechargeable battery such as a lithium ion battery or a nickel-metal hydride battery. The electronic device 100 receives power from the external device 200 to charge the secondary battery 141. Although the electronic device 100 appears to include the secondary battery 141 in FIG. 1, the electronic device 100 may not include the secondary battery 141 while the power is not turned on. For example, the electronic device 100 may include a battery box in which a commercially available secondary battery 141 (such as a nickel-metal hydride battery) is set, and a user may set the commercially available secondary battery 141 in the battery box before turning on the power of the electronic device 100.

[0021] The operation of the charging circuit 120 when charging the secondary battery 141 will be described with reference to Fig. 2. By connecting the connector 220 of the external device 200 to the connector 170 of the electronic device 100 and inserting the plug of the external device 200 into an outlet, the external device 200 normally supplies a constant output voltage Vo to the electronic device 100.

[0022] Since a voltage drop occurs due to contact resistance 190 between connector 220 and connector 170, the output voltage Vo of external device 200 is reduced by this voltage drop to become the input voltage Vi at connector 170 of electronic device 100. However, since the contact resistance 190 is usually a negligibly small value, it may be considered that Vo=Vi.

[0023] When the remaining charge of the secondary battery 141 is smaller than the pre-charge threshold, the charge control unit 140 performs pre-charge with a charging current (e.g., 20 mA; Cp in FIG. 2) that is equal to or less than one-fifth of the charging current (e.g., 125 mA; Cc in FIG. 2) in normal constant current (CC) charging in order to avoid placing a burden on the secondary battery 141 during charging. Then, when the remaining charge of the secondary battery 141 reaches or exceeds the pre-charge threshold, the charge control unit 140 switches the charging state from pre-charge to CC charging. Note that if the remaining charge of the secondary battery 141 is equal to or greater than the pre-charge threshold at the time charging starts, pre-charge is not performed and CC charging is performed from the beginning.

[0024] In CC charging, the charging control unit 140 charges the secondary battery 141 with a constant charging current (for example, 125 mA; Cc in FIG. 2). Then, when the output voltage of the secondary battery 141 reaches a switching voltage (Vc in FIG. 2) due to CC charging, the charging control unit 140 switches the charging state from CC charging to constant voltage (CV) charging.

[0025] In CV charging, the charging control unit 140 charges the secondary battery 141 at a constant voltage (Vc in FIG. 2). When CV charging is performed, the charging current flowing through the secondary battery 141 decreases over time, but when the charging current reaches a charging termination current value (for example, 20 mA; Cp in FIG. 2), the charging control unit 140 terminates charging of the secondary battery 141.

[0026] In this way, the charging control unit 140 knows the current charging state (pre-charging, CC charging, CV charging, charging stopped) and stores the charging state in a specific register included in the charging control IC. Therefore, the control unit 131 can obtain the current charging state by reading out the value of the specific register of the charging control IC included in the charging control unit 140. In addition, since the charging state changes based on changes in the battery voltage and charging current as shown in Fig. 2, the control unit 131 can also obtain the charging state based on the measurement result by the first measuring unit 150. In addition, in Fig. 2, the pre-charging time zone is represented by a, the CC charging time zone is represented by b, the CV charging time zone is represented by c, and the charging stop time zone is represented by d.

[0027] When the contact resistance 190 is small enough to be ignored, charging is performed normally as shown in Fig. 2. However, when the contact resistance 190 is large, as shown in Fig. 3, the input voltage Va at the connector 170 becomes smaller than the original value Vi (=Vo), for example as shown by the dotted line 301, and the current (charging current) flowing through the secondary battery 141 also becomes smaller than the original value as shown by the dotted line 302. This causes problems (charging abnormalities) such as a longer time required for charging or incomplete charging.

[0028] To determine whether or not this charging abnormality has occurred, the control unit 131 compares the measurement result by the second measuring unit 160 with a threshold value according to the charging state, and determines that a charging abnormality has occurred if the measurement result is smaller than the threshold value.

[0029] There are two types of measurement results by the second measuring unit 160: the current (charging current) flowing through the secondary battery 141 and the voltage (input voltage) at the connector 170. Here, a case will be described in which the charging current is measured and the measurement result is compared with a threshold value according to the charging state. That is, if the charging state is pre-charging, it is compared with a threshold value Cta during pre-charging (e.g., half the charging current Cp during pre-charging), if the charging state is CC charging, it is compared with a threshold value Ctb during CC charging (e.g., half the charging current Cc during CC charging), and if the charging state is CV charging, it is compared with a threshold value Ctc during CV charging (e.g., half the charging end current. In FIG. 3, Cta=Ctc, but this is not limited thereto). Then, if the magnitude of the charging current is smaller than the threshold value, it is determined that a malfunction has occurred.

[0030] As shown in the input voltage graph in Figure 3, if contact resistance 190 is large from the beginning and input voltage Va is significantly smaller than the original value Vi, the charging current will be significantly smaller, so that in reality, CC charging will not end or it will take a long time to switch to CV charging. However, in Figure 3, in order to show that the charging current will be smaller regardless of when contact resistance 190 becomes large, the charging current graph is shown by a dotted line 302, assuming that CC charging switches to CV charging in approximately the same time as in Figure 2.

[0031] Next, a case will be described in which the input voltage at the connector 170 is measured as a measurement result by the second measuring unit 160, and the measurement result is compared with a threshold value according to the charging state. To achieve this explanation, first, the relationship between the difference (voltage difference Dv) between the input voltage Vi and the battery voltage Vc, and the charging current of the secondary battery 141 will be described.

[0032] As shown in FIG. 4, when the voltage difference Dv becomes smaller than a certain value, the charging current flowing through the secondary battery 141 becomes almost zero, and charging is no longer performed. In the example shown in FIG. 4, if the voltage difference Dv is about 0.192V or more, 20mA (charging current Cp during preliminary charging) can flow. However, for example, when the voltage difference Dv becomes less than 0.186V, the charging current becomes less than 10mA (threshold Cta during preliminary charging). Therefore, during preliminary charging, a voltage threshold is set so that a malfunction is determined when the voltage difference Dv becomes less than 0.186V. In order to simplify this determination process, the voltage threshold Vta during preliminary charging may be set to a value obtained by subtracting the voltage difference Dv (0.186V in FIG. 4) at which the charging current becomes Cta from the maximum battery voltage Vc.

[0033] Also, in the example shown in FIG. 4, if the voltage difference Dv is about 0.36V or more, 125mA (the charging current Cc during CC charging) can flow. However, for example, if the voltage difference Dv becomes less than about 0.22V, the charging current becomes less than 62.5mA (the threshold Ctb during CC charging). Therefore, during CC charging, the voltage threshold is set so that a malfunction is determined when the voltage difference Dv becomes less than 0.22V. Also, to simplify this determination process, the voltage threshold Vtb during CC charging may be set to a value obtained by subtracting the voltage difference Dv (0.22V in FIG. 4) at which the charging current becomes Ctb from the maximum battery voltage Vc.

[0034] The above-mentioned settings can also be used when the charging state is CV charging. However, the values ​​shown in Fig. 4 are merely examples, and the above-mentioned values ​​need to be adjusted according to the characteristics of the secondary battery 141 and electronic components actually used.

[0035] Next, the abnormality determination process executed by the electronic device 100 will be described with reference to Fig. 5. This process starts when the power supply of the electronic device 100 is turned on.

[0036] First, the control unit 131 acquires the measurement result from the first measurement unit 150 (step S101). Next, the control unit 131 acquires the current charging state (step S102). Step S102 is also called a state acquisition step. Note that the control unit 131 may acquire the charging state based on the measurement result from the first measurement unit 150, or may acquire the charging state directly from the charging control unit 140 (by reading the value of a specific register of the charging control IC, for example). When the control unit 131 acquires the charging state directly from the charging control unit 140, step S101 is not necessary.

[0037] Then, the control unit 131 determines whether charging is stopped or not based on the acquired charging state (step S103). If charging is stopped (step S103; Yes), the process returns to step S101.

[0038] If charging is not stopped (step S103; No), the control unit 131 sets a threshold value according to the charging state acquired in step S102 (step S104). For example, as the threshold value of the charging current, if pre-charging is in progress, Cta (e.g., 10 mA) is set, if CC charging is in progress, Ctb (e.g., 62.5 mA) is set, and if CV charging is in progress, Ctc (e.g., 10 mA) is set.

[0039] Then, the control unit 131 acquires the measurement result from the second measuring unit 160 (step S105). Step S105 is also called a measurement step. Next, the control unit 131 determines whether the measurement result from the second measuring unit 160 is less than a threshold value (step S106). Step S106 is also called a determination step. In step S106, for example, it is determined whether the charging current flowing through the secondary battery 141 measured by the second measuring unit 160 is less than a threshold value (Cta, Ctb, Ctc) according to the charging state.

[0040] If the measurement result by the second measuring unit 160 is equal to or greater than the threshold (step S106; No), the process returns to step S101. If the measurement result by the second measuring unit 160 is less than the threshold (step S106; Yes), the control unit 131 determines that a malfunction has occurred and notifies the notification unit 133 of a charging abnormality (step S107). For example, the notification unit 133 may turn on an LED or sound a buzzer. Then, the process returns to step S101.

[0041] By the above-described abnormality determination process, the electronic device 100 can determine an abnormality based on a threshold value according to the charging state, and therefore can more reliably detect an increase in the contact resistance in the connector. Moreover, the electronic device 100 can notify the user by the notification unit 133 that a charging abnormality has occurred.

[0042] (Variation 1) The electronic device 100 may include a temperature sensor such as a thermistor as a means for acquiring the temperature of the battery (temperature acquisition means). The charging control unit 140 may control the charging voltage and the charging current based on the temperature acquired by the temperature acquisition means. This is because the secondary battery 141 may lose charging efficiency or may not be able to be normally charged in an extremely low or high temperature environment.

[0043] For example, the charging control unit 140 may stop charging when the temperature is below 0 degrees Celsius or above 60 degrees Celsius, and may set the charging voltage to a value lower than normal (e.g., 95% of the normal value) when the temperature is between 0 and 10 degrees Celsius or between 45 and 60 degrees Celsius.

[0044] In this case, the control unit 131 also acquires the battery temperature, for example, in step S101 in Fig. 5. Then, if the temperature is less than 0 degrees Celsius or greater than 60 degrees Celsius (because charging is stopped), the process returns to step S101 in step S102 in Fig. 5. Then, in step S103, the control unit 131 sets the threshold value for the charging voltage, taking into consideration that the charging voltage is lower than normal when the temperature is greater than or equal to 0 degrees Celsius and less than 10 degrees Celsius, and greater than or equal to 45 degrees Celsius and less than 60 degrees Celsius.

[0045] As another example, the charging control unit 140 may stop charging when the temperature is below 0 degrees Celsius or above 60 degrees Celsius, set the charging current to a value lower than normal (for example, 60% of the normal value) when the temperature is between 0 and 10 degrees Celsius, and set the charging voltage to a value lower than normal (for example, 95% of the normal value) when the temperature is between 45 and 60 degrees Celsius.

[0046] In this case, the control unit 131 also acquires the battery temperature, for example, in step S101 in Fig. 5. Then, when the temperature is less than 0 degrees Celsius or greater than 60 degrees Celsius (because charging is stopped), the process returns to step S101 in step S102 in Fig. 5. Then, in step S103, the control unit 131 sets a threshold value for the charging current taking into consideration that the charging current is lower than normal when the temperature is greater than or equal to 0 degrees Celsius and less than 10 degrees Celsius, and sets a threshold value for the charging voltage taking into consideration that the charging voltage is lower than normal when the temperature is greater than or equal to 45 degrees Celsius and less than 60 degrees Celsius.

[0047] By performing an abnormality determination process that takes temperature into consideration in this manner, an increase in contact resistance in the connector can be detected more reliably even when the charging current or charging voltage changes depending on the temperature.

[0048] (Variation 2) The charging characteristics of the secondary battery 141 also differ depending on the temperature. For example, at room temperature (e.g., 23 degrees Celsius), the ratio of the CC charging time to the CV charging time is such that the CC charging time is longer as shown in Fig. 2, whereas at low temperatures (e.g., 6 degrees Celsius), the ratio of the CC charging time to the CV charging time is such that the CV charging time is longer as shown in Fig. 6.

[0049] Therefore, the threshold value for the CV charging time period may be set in multiple stages. For example, as shown in Fig. 6, the threshold value for the charging current immediately after the charging state is switched to CV charging may be set to a threshold value Ctc1 that is about half the Ctb value, and midway through (for example, after half the time required for CV charging and the time expected to be required) the threshold value for the charging current may be changed to a threshold value Ctc2 that is about half the charging end current. By setting the threshold value for the CV charging time period in multiple stages in this way, even if a malfunction (an increase in contact resistance 190) occurs immediately after switching to CV charging, the occurrence of the malfunction can be determined relatively quickly.

[0050] 6, the threshold value for the CV charging time period is set in two stages (Ctc1 and Ctc2), but it may be set in three or more stages. Also, the threshold value for the CV charging time period may be set in multiple stages regardless of temperature (for example, even at room temperature).

[0051] Second embodiment A second embodiment will be described in which the electronic device and the external device communicate with each other and the external device increases the output voltage when a malfunction occurs. As shown in FIG. 7, a charging system 1001 according to the second embodiment includes an electronic device 101 and an external device 201.

[0052] The electronic device 101 has a configuration in which a transmission unit 134 is added to the electronic device 100 according to the first embodiment. Also, the external device 201 has a configuration in which a reception unit 230 and a voltage control unit 240 are added to the external device 200 according to the first embodiment.

[0053] The transmitting unit 134 includes a communication device and transmits a notification signal to the receiving unit 230. The receiving unit 230 also includes a communication device and receives the notification signal transmitted from the transmitting unit 134. The notification signal will be described later. The transmitting unit 134 and the receiving unit 230 may use any communication method. For example, they may communicate wirelessly using a wireless LAN (Local Area Network) or the like, or may communicate wiredly using a USB (Universal Serial Bus) or the like.

[0054] In addition, when communicating by wire, a communication cable may be provided in parallel to the power cable via connector 170 and connector 220, or a communication cable may be provided independent of the power cable. Also, communication may be performed using only the power cable by superimposing the notification signal on the power flowing through the power cable. However, when communicating by wire, it is necessary to prevent errors from occurring in communication of the notification signal even if contact resistance 190 becomes large. Therefore, taking contact resistance 190 into consideration, it is desirable for transmitter 134 and receiver 230 to communicate with each other wirelessly.

[0055] Voltage control unit 240 includes a processor such as a CPU and a memory, and controls the magnitude of the voltage output by output unit 210 in response to the notification signal received by receiving unit 230. Specifically, voltage control unit 240 increases the output voltage output from output unit 210 by the amount of the voltage notified by the notification signal, thereby enabling power to be supplied to electronic device 101 at a higher voltage.

[0056] Here, the notification signal will be explained. This notification signal is a signal for notifying the external device 201 of a voltage increase value Vu (a value indicating how much the output voltage should be increased from normal). The voltage increase value is calculated by the control unit 131 from the current charging state, input voltage, and battery voltage, based on the relationship between the voltage difference Dv (the difference between the input voltage and the battery voltage) and the charging current as shown in Fig. 4.

[0057] For example, as the contact resistance 190 increases, the input voltage Vi decreases, and as a result, when the difference (voltage difference Dv) between the input voltage Vi and the battery voltage Vc decreases to a certain level or more, the charging current flowing through the secondary battery 141 becomes almost zero as shown in Fig. 4, and charging ceases. To prevent charging from being suspended in this way, the output voltage Vo of the external device 201 is increased by a notification signal, thereby preventing the voltage difference Dv from decreasing to a certain level or more.

[0058] For example, in the example shown in FIG. 4, if the voltage difference Dv is about 0.192V or more, 20mA (charging current Cp during preliminary charging) can flow. However, if the voltage difference Dv becomes less than 0.186V, the charging current becomes less than 10mA (threshold Cta during preliminary charging). Therefore, if the voltage difference Dv is less than 0.192V, by increasing the output voltage Vo of the external device 201 by 0.192-Dv, the input voltage Vi also increases accordingly, the voltage difference Dv becomes about 0.192V, and it is considered that the charging current Cp during preliminary charging can be maintained. That is, in the case of the secondary battery 141 having the characteristics shown in FIG. 4, during preliminary charging, the control unit 131 transmits a value calculated as the voltage increase value Vu=0.192-Dv as a notification signal from the transmission unit 134 to the reception unit 230.

[0059] Also, for example, in the example shown in FIG. 4, if the voltage difference Dv is about 0.36V or more, 125mA (the charging current Cc during CC charging) can flow. However, if the voltage difference Dv becomes less than about 0.22V, the charging current becomes less than 62.5mA (the threshold value Ctb during CC charging). Therefore, if the voltage difference Dv is less than 0.36V, by increasing the output voltage Vo of the external device 201 by 0.36-Dv, the input voltage Vi also increases accordingly, the voltage difference Dv becomes about 0.36V, and it is considered that the charging current Cc during CC charging can be maintained. That is, in the case of the secondary battery 141 having the characteristics shown in FIG. 4, during CC charging, the control unit 131 transmits a value calculated as the voltage increase value Vu=0.36-Dv as a notification signal from the transmission unit 134 to the reception unit 230.

[0060] When the charging state is CV charging, the necessary charging current decreases as time passes, but the control unit 131 can obtain the voltage difference Dvr that can maintain the necessary charging current Ct at each point in time in the same manner as described above, for example, from the characteristics shown in Fig. 4 and the characteristics shown in Fig. 2. Then, when the voltage difference Dv is less than Dvr, if the output voltage Vo of the external device 201 is increased by Dvr-Dv, the input voltage Vi also increases accordingly, the voltage difference Dv becomes almost Dvr, and it is considered that the charging current Ct at that point in time of CV charging can be maintained. In other words, during CV charging, the control unit 131 transmits a value calculated as the voltage increase value Vu=Dvr-Dv at the time when the charging abnormality is determined from the transmission unit 134 to the reception unit 230 as a notification signal.

[0061] Other configurations of the second embodiment are similar to those of the first embodiment, and therefore description thereof will be omitted.

[0062] Next, the abnormality determination process executed by the electronic device 101 will be described with reference to Fig. 8. This process starts when the power supply of the electronic device 101 is turned on. Also, the processes from step S101 to step S107 are similar to the abnormality determination process (Fig. 5) according to the first embodiment, and therefore the description thereof will be omitted.

[0063] After step S107, the control unit 131 transmits the above-mentioned notification signal to the external device 201 via the transmission unit 134 (step S108). Since there may be a slight time lag before the output voltage from the external device 201 increases due to the notification signal transmitted in step S108, a process of waiting for a certain period of time (for example, several seconds) may be performed after the process in step S108. Then, the process returns to step S101.

[0064] Next, a voltage control process executed by the external device 201 will be described with reference to Fig. 9. This process starts when the power supply of the external device 201 is turned on.

[0065] First, the voltage control unit 240 initializes the value of the output voltage Vo output from the output unit 210 to a normal voltage (for example, 5 V) (step S201).

[0066] Then, the voltage control unit 240 causes the output unit 210 to output power at the output voltage Vo (step S202). Next, the voltage control unit 240 determines whether or not the receiving unit 230 has received a notification signal (step S203). If the notification signal has not been received (step S203; No), the process returns to step S203 and waits until the notification signal is received.

[0067] When the notification signal is received (step S203; Yes), the voltage control unit 240 increases the output voltage Vo in accordance with the received notification signal (step S204), and returns to step S202 to cause the output unit 210 to output power of the increased output voltage Vo.

[0068] In the above process, the control unit 131 calculates the voltage increase value Vu and transmits the calculated voltage increase value Vu to the external device 201 as a notification signal, but the control unit 131 does not necessarily have to calculate the voltage increase value Vu. For example, the control unit 131 may not calculate the voltage increase value Vu in step S108, but may transmit a notification signal simply notifying that the voltage will be increased, and upon receiving the notification signal, the voltage control unit 240 may increase the output voltage Vo by a preset voltage value (for example, 1 V) in step S204.

[0069] The abnormality determination process (FIG. 8) and voltage control process (FIG. 9) according to the second embodiment have been described above. With these processes, when an increase in contact resistance in the connector is detected in the charging system 1001 according to the second embodiment, not only is the user notified of the abnormality, but the voltage output from the external device 201 can be increased. As a result, in the charging system 1001, charging can be performed in the same charging time as in normal charging, even in a state in which the contact resistance in the connector is increased.

[0070] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, it is possible to configure an embodiment in which the second embodiment and the first modification are combined, or an embodiment in which the second embodiment and the second modification are combined.

[0071] Note that each function of the electronic devices 100, 101 can also be implemented by a computer such as a normal PC (Personal Computer). Specifically, in the above embodiment, the program for the abnormality determination process performed by the electronic devices 100, 101 has been described as being stored in advance in the ROM of the storage unit 132. However, the program may be stored in a computer-readable recording medium such as a flexible disk, a CD-ROM (Compact Disc Read Only Memory), a DVD (Digital Versatile Disc), an MO (Magneto-Optical disc), a memory card, a USB memory, or the like, and distributed, and the program may be read and installed in a computer to configure a computer capable of implementing each of the above-mentioned functions.

[0072] Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment, and the present invention includes the inventions described in the claims and their equivalents. The inventions described in the original claims of this application are listed below.

[0073] (Appendix 1) A connector for connecting to an external device; a measurement unit that measures a current flowing through a secondary battery that is electrically connected to the external device and receives power therefrom, or a voltage at the connector; acquiring a charging state of the secondary battery; determining whether or not an abnormality has occurred in a connection state between the external device and the electronic device based on the acquired charging state and the measurement result by the measurement unit; A control unit; An electronic device comprising:

[0074] (Appendix 2) The control unit is determining whether the abnormality has occurred by comparing a threshold value set according to the acquired charging state with the measurement result of the measurement unit; 2. The electronic device according to claim 1.

[0075] (Appendix 3) Further comprising an alarm unit that notifies the abnormality, When the control unit determines that the abnormality has occurred, the control unit notifies the abnormality through the notification unit. 3. An electronic device according to claim 1 or 2.

[0076] (Appendix 4) A transmitter for transmitting a notification signal to the external device, When it is determined that the abnormality has occurred, the control unit controls the transmission unit to transmit the notification signal to the external device, thereby controlling power supply to the external device to be performed at a higher voltage. 4. An electronic device according to any one of claims 1 to 3.

[0077] (Appendix 5) an output section for supplying power to an electronic device; a receiving unit for receiving a notification signal from the electronic device; a voltage control unit that increases a voltage output from the output unit in response to the notification signal when the receiving unit receives the notification signal; An external device comprising:

[0078] (Appendix 6) A charging system including an electronic device and an external device electrically connected to the electronic device, The electronic device includes: A connector connected to the external device; a measurement unit that measures a current flowing through a secondary battery that is electrically connected to the external device and receives power therefrom, or a voltage at the connector; acquiring a charging state of the secondary battery; determining whether or not an abnormality has occurred in a connection state between the external device and the electronic device based on the acquired charging state and the measurement result by the measurement unit; A control unit; Equipped with The external device is An output unit for supplying power to the electronic device. Charging system.

[0079] (Appendix 7) a measurement step of measuring a current flowing through a secondary battery that is electrically connected to an external device and receives power therefrom, or a voltage at a connector of an electronic device that is connected to the external device; a state acquisition step of acquiring a state of charge of the secondary battery; a determination step of determining whether or not an abnormality has occurred in a connection state between the external device and the electronic device based on the charging state acquired in the state acquisition step and the measurement result in the measurement step; A charging method comprising:

[0080] (Appendix 8) On the computer, A measurement step of measuring a current flowing through a secondary battery that is electrically connected to an external device and receives power therefrom, or a voltage at a connector of an electronic device that is connected to the external device; a state acquisition step of acquiring a state of charge of the secondary battery; and a determination step of determining whether or not an abnormality has occurred in a connection state between the external device and the electronic device based on the charging state acquired in the state acquisition step and the measurement result in the measurement step; A program that executes the following. [Explanation of symbols]

[0081] 100, 101...electronic device, 110...main circuit, 120...charging circuit, 131...control unit, 132...storage unit, 133...alert unit, 134...transmission unit, 140...charging control unit, 141...secondary battery, 150...first measurement unit, 160...second measurement unit, 161...resistance, 170, 220...connector, 190...contact resistance, 200, 201...external device, 210...output unit, 230...receiving unit, 240...voltage control unit, 301, 302...dotted lines, 1000, 1001...charging system

Claims

1. A connector for connecting to an external device; A first measurement unit that measures at least a voltage of the secondary battery; a second measurement unit that measures at least a current flowing through the secondary battery that is electrically connected to the external device and receives power; A control unit, The control unit is acquiring at least one of a CC charging state, a CV charging state, and a charging stop state as a charging state of the secondary battery based on the voltage measured by the first measuring unit; By comparing the measured current with a current threshold value set according to the charging state at the time of acquiring the acquired charging state among the CC charging state, the CV charging state, and the charging stop state, it is determined whether or not an abnormality has occurred in the connection state between the external device and the electronic device. electronic equipment.

2. The second measurement unit is capable of measuring a voltage at the connector, The control unit is determining whether or not an abnormality has occurred in a connection state between the external device and the electronic device based on either one of the measured current and the measured voltage at the connector and the acquired charging state; 2. The electronic device according to claim 1.

3. Further comprising an alarm unit that notifies the abnormality, When the control unit determines that the abnormality has occurred, the control unit causes the notification unit to notify the abnormality.

3. The electronic device according to claim 1 or 2.

4. A transmitter for transmitting a notification signal to the external device, When it is determined that the abnormality has occurred, the control unit controls the transmission unit to transmit the notification signal to the external device, thereby controlling the external device to supply power at a higher voltage. The electronic device according to claim 1 .

5. The control unit is Setting a plurality of threshold values ​​of the current in the CV charging state; 2. The electronic device according to claim 1.

6. A temperature sensor for measuring a temperature of the secondary battery is further provided. The control unit is When the temperature of the secondary battery measured by the temperature sensor is equal to or lower than a predetermined temperature threshold, a plurality of current thresholds in the CV charging state are set.

6. The electronic device according to claim 5.

7. A charging system including an electronic device and an external device electrically connected to the electronic device, The electronic device includes: A connector connected to the external device; A first measurement unit that measures at least a voltage of the secondary battery; a second measurement unit that measures at least a current flowing through the secondary battery that is electrically connected to the external device and receives power; A control unit, The control unit is acquiring at least one of a CC charging state, a CV charging state, and a charging stop state as a charging state of the secondary battery based on the voltage measured by the first measuring unit; determining whether or not an abnormality has occurred in a connection state between the external device and an electronic device by comparing the measured current with a current threshold value set according to the charging state at the time of acquiring the acquired charging state among the CC charging state, the CV charging state, and the charging stop state; The external device includes: An output unit for supplying power to the electronic device. Charging system.

8. The computer Measure at least the voltage at the secondary battery; At least measuring a current flowing through the secondary battery which is electrically connected to an external device and receives power therefrom; Based on the measured voltage, at least one of a CC charging state, a CV charging state, and a charging stop state is obtained as a charging state of the secondary battery; By comparing the measured current with a current threshold value set according to the charging state at the time of acquiring the acquired charging state among the CC charging state, the CV charging state, and the charging stop state, it is determined whether or not an abnormality has occurred in the connection state between the external device and the electronic device. Charging method.

9. On the computer, Measure at least the voltage at the secondary battery; At least measuring a current flowing through the secondary battery which is electrically connected to an external device and receives power therefrom; Based on the measured voltage, at least one of a CC charging state, a CV charging state, and a charging stop state is obtained as a charging state of the secondary battery; By comparing the measured current with a current threshold value set according to the charging state at the time of acquiring the acquired charging state among the CC charging state, the CV charging state, and the charging stop state, it is determined whether or not an abnormality has occurred in the connection state between the external device and the electronic device. A program that executes a process.

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