JP7021431B2 - Charging system, charger, and program - Google Patents

Description

The present invention relates to charging systems, chargers, and programs.

In recent years, electronic devices such as smartphones that use a secondary battery as a power source have become widespread. For such electronic devices, the charger that charges the secondary battery is connected to the electronic device and the charger even after the secondary battery has been charged to the maximum capacity (after it is fully charged). The current situation is that the secondary battery of the electronic device is continuously supplied with current so as to maintain the fully charged state while the battery is being charged.

In recent years, portable chargers (so-called mobile batteries) that use dry batteries or secondary batteries as power sources to charge electronic devices such as smartphones have also become widespread. As a usage mode of such a mobile battery, for example, a smartphone user generally uses the smartphone while charging with the mobile battery. In this case, the secondary battery on the smartphone side is charged while supplying electric power.

In addition, Patent Document 1 discloses a technique for repeatedly performing comparison and determination between the remaining battery value and the upper limit value to perform energization and interruption of energization in order to prevent battery deterioration due to full charge of the mobile terminal. ..

Japanese Unexamined Patent Publication No. 2015-144519

As described above, in the above-mentioned conventional charger, the current is continuously supplied to the secondary battery for a long period of time in order to maintain a fully charged state or a state close to the full charge, and when overcharging occurs, the secondary battery deteriorates. May be invited. Further, in the usage mode in which power is supplied while charging, the secondary battery generates heat due to the load, and deterioration is more likely to occur as compared with the case where either operation is performed. However, if the charging current is cut off after the battery is fully charged, if the battery is left unattended after that, the secondary battery will be discharged due to the standby operation of a smartphone or the like, and over-discharge may occur depending on the time of leaving. be.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a charging system, a charger, and a program capable of preventing overcharging / overdischarging and reducing the load on a battery. Make it one.

The present invention, which solves the problems of the above-mentioned conventional example, is a charging system including a charger and an electronic device charged by the charger, wherein the electronic device is supplied from a secondary battery and the charger. A means for charging the secondary battery with the generated power, and a communication means for transmitting a signal for controlling the on / off of the charging current to the charger based on the charge amount of the secondary battery. Including, the charger receives a signal for controlling on / off of the charging current from the electronic device, and switches and controls the supply start and the supply stop of the charging current.

In this way, since the charging current is cut off and supplied by the control from the electronic device side, the electronic device side can control the charging state according to its own situation, prevent overcharging / overdischarging, and reduce the load on the battery. Can be controlled to mitigate.

Further, the charging system according to one aspect of the present invention includes a charger and an electronic device charged by the charger, and the electronic device includes a secondary battery and the electric power supplied from the charger. A control signal for setting a charging current for the charger based on a means for charging the secondary battery, a functional unit operated by the power supplied by the secondary battery, and conditions related to the operation of the functional unit. The charger includes a communication means for transmitting, and the charger receives a signal for setting a charging current from the electronic device and controls the supply amount of the charging current.

In this way, since the amount of charging current is controlled from the electronic device side, the electronic device side can control the charging state according to the conditions related to the operation of the functional unit possessed by the electronic device, and overcharge / overdischarge can be prevented. , Can be controlled to reduce the load on the battery.

Further, the charger according to another aspect of the present invention is a charger that is connected to an electronic device including a secondary battery and supplies a charging current to the electronic device, and the charging current is turned on / off from the electronic device. It is decided to have a means for receiving a signal for controlling the above, and a switch means for switching between a state of supplying the charging current to the electronic device and a state of stopping the supply of the charging current according to the received signal. It is a thing.

In this way, since it was decided to cut off and supply the charging current by controlling from the electronic device side, the electronic device side can control the charging state according to its own situation, and the electronic device can be overcharged / overdischarged. Can be controlled to reduce the load on the battery.

Further, the charger according to still another aspect of the present invention is a charger that is connected to an electronic device including a secondary battery and supplies a charging current to the electronic device, and a charging current is set from the electronic device. It is provided with a means for receiving the control signal and a supply control means for controlling the supply amount of the charging current to the electronic device according to the received signal.

In this way, since the amount of charging current is controlled from the electronic device side, the electronic device side can control the charging state according to its own situation, and the electronic device can be overcharged / overdischarged. It can be controlled to prevent and reduce the load on the battery.

Here, the supply control means uses a signal received from the electronic device as a current output unit having a plurality of terminals for supplying currents having different current amounts from each other and one of the plurality of terminals included in the current output unit. It is also preferable to have a switch means for connecting the selected terminal and the current supply terminal to the electronic device. This makes the configuration simple.

Further, the program according to one aspect of the present invention is a means for detecting the charge amount of the secondary battery in an electronic device having a secondary battery charged by power supplied from a charger connected to the outside, and the above-mentioned. Based on the detected charge amount, the charger is made to function as a communication means for transmitting a signal for controlling on / off of the charge current.

Further, the program according to another aspect of the present invention is a functional unit that operates an electronic device having a secondary battery charged by power supplied from a charger connected to the outside by the power supplied by the secondary battery. It is intended to function as a means for acquiring the conditions related to the operation of the above and a communication means for transmitting a control signal for setting the charging current to the charger based on the acquired conditions.

According to the present invention, it is possible to prevent overcharging / overdischarging of a battery of an electronic device and reduce the load applied to the battery.

It is a block diagram which shows the example of the charging system which concerns on embodiment of this invention. It is a functional block diagram of the control part of the electronic device which concerns on embodiment of this invention. It is explanatory drawing which shows the setting example of the condition in the electronic device which concerns on embodiment of this invention. It is a schematic circuit diagram which shows the structural example of the charge control part of the charger which concerns on embodiment of this invention. It is explanatory drawing which shows an example of the operation of the charging system which concerns on embodiment of this invention. It is a schematic circuit diagram which shows another structural example of the charge control part of the charger which concerns on embodiment of this invention. It is a schematic block diagram which shows still another structural example of the charge control part of the charger which concerns on embodiment of this invention.

An embodiment of the present invention will be described with reference to the drawings. As illustrated in FIG. 1, the charging system 1 according to the embodiment of the present invention includes a charger 10 and an electronic device 20 for which charging is performed.

Further, as illustrated in FIG. 1, the charger 10 includes a power supply unit 11, a control unit 12, a communication unit 13, a charge control unit 14, and a power supply unit 15. Further, the electronic device 20 is, for example, a smartphone, and includes a control unit 21, a storage unit 22, an operation unit 23, a display unit 24, a communication unit 25, a power receiving unit 26, and a power supply unit 27. Will be done.

Here, the power supply unit 11 of the charger 10 includes, for example, a secondary battery, and the power supplied by the secondary battery follows the instructions of the charge control unit 14. Specifically, the power supply unit 11 supplies an instructed amount of electric power to an external device (electronic device 20 or the like) connected to the power supply unit 15 via the power supply unit 15.

The control unit 12 is a microcomputer or the like, and operates according to a program stored in the built-in memory. The control unit 12 receives a signal for controlling the charge current from the electronic device 20 via the communication unit 13, and causes the charge control unit 14 to control the charge current based on the received signal. The operation of the control unit 12 will be described in detail later.

The communication unit 13 is a wireless LAN interface, a short-range wireless communication interface (Bluetooth (registered trademark), etc.), a wired network interface, or the like, and transmits and receives signals to and from the electronic device 20. In an example of this embodiment, the communication unit 13 outputs a signal wirelessly received from the electronic device 20 to the control unit 12.

The charge control unit 14 controls the amount of charge current supplied by the power supply unit 11 via the power supply unit 15 according to the instruction input from the control unit 12. In one example of the present embodiment, the charge control unit 14 switches between a charge current amount defined as a current amount to be supplied during charging and a current amount “0” according to an instruction input from the control unit 12.

Further, in another example of the present invention, the charge control unit 14 is supplied from the power supply unit 11 so as to supply the charge current by the amount of the current specified by the instruction according to the instruction input from the control unit 12. Control the amount of current. This amount of current may be controlled within a predetermined range arbitrarily set by, for example, a DC / DC converter, or one of a plurality of terminals that supply a predetermined amount of current different from each other is selected. May be controlled by. A specific example of the charge control unit 14 will be described later.

The power supply unit 15 is connected to the electronic device 20 and has a current supply terminal that supplies the charging current in the amount of current controlled by the charge control unit 14 to the electronic device 20. As an example of this implementation, the power supply unit 15 may be a USB (Universal Serial Bus) terminal. When a USB terminal is used, the power supply unit 15 supplies power for charging to the electronic device 20 via the power supply terminal included in the USB terminal and the GND terminal. The charge control unit 14 and the power supply unit 15 realize the supply control means of the present invention. Further, the power supply unit 15 realizes the current output unit of the present invention.

The control unit 21 of the electronic device 20 is a program control device such as a CPU, and operates according to a program stored in the storage unit 22. In one example of the present embodiment, the control unit 21 executes a process for realizing the function as the electronic device 20. For example, if the electronic device 20 is a smartphone, the control unit 21 executes an operating system process, and under the control of the operating system, executes a telephone function function process, and a microphone (not shown) collects sound. The generated voice is encoded and transmitted to the mobile phone network via the mobile phone communication unit (not shown) of the communication unit 25. Further, the control unit 21 outputs the voice obtained by decoding the signal received from the mobile phone network to a speaker (not shown) and makes it ring.

Further, when the electronic device 20 is a smartphone, the control unit 21 executes processing based on various application programs such as a game program under the control of the operating system. In one example of this embodiment, the control unit 21 executes the charge control process as one of the operations according to this application program. The control unit 21 that performs this charge control process examines the charge amount of the power supply unit 27, which is a secondary battery of the electronic device 20, and outputs a signal for controlling the charge current according to a predetermined rule based on the charge amount. It is generated and the signal is transmitted to the charger 10 via the communication unit 25. This process of the control unit 21 will be described in detail later.

The storage unit 22 is a memory device, a disk device, or the like, and holds a program executed by the control unit 21. This program is provided in a state of being stored in a computer-readable and non-temporary recording medium, and may be stored in the storage unit 22 from the recording medium, or may be received via a network and this storage. It may be stored in the unit 22. The storage unit 22 also operates as a work memory for the control unit 21.

The operation unit 23 is, for example, a touch panel, a keyboard, a switch, or the like, and receives a user's operation instruction and outputs the content of the operation instruction to the control unit 21. The display unit 24 is a liquid crystal display or the like, and displays and outputs information according to an instruction input from the control unit 21.

If the electronic device 20 is a mobile phone such as a smartphone, the communication unit 25 includes a mobile phone communication means for communicating with the mobile phone line network. Further, the communication unit 25 includes a wireless LAN interface for communicating with the charger 10, a short-range wireless communication interface (Bluetooth (registered trademark), etc.), a wired network interface, and the like. The communication unit 25 sends a signal for controlling the charging current to the charger 10 according to an instruction input from the control unit 21.

The power receiving unit 26 is connected to the power supply unit 15 of the charger 10. The power receiving unit 26 becomes a USB receptacle when the power supply unit 15 is a USB terminal. The power receiving unit 26 receives the charging current supplied from the charger 10 and supplies it to the power supply unit 27. The power supply unit 27 has a secondary battery, and when a charging current is supplied from the charger 10 via the power receiving unit 26, the secondary battery is charged by the charging current. Further, the power supply unit 27 includes each unit of the electronic device 20 (control unit 21, storage unit 22, operation unit 23, display unit 24, communication unit 25, and GPS (Global Positioning System) that the electronic device 20 can include (not shown). Power is supplied to an activity sensor, a vibrator, and other parts that operate by receiving power supply in order to provide functions as an electronic device 20; hereinafter, these are collectively referred to as a functional part).

Next, the operation of the control unit 21, which is one of the functional units of the electronic device 20, will be described. By executing the program stored in the storage unit 22, the control unit 21 functionally comprises the setting unit 31, the condition determination unit 32, the current amount determination unit 33, and the current amount determination unit 33, as illustrated in FIG. It is configured to include a signal transmission unit 34.

In the present embodiment, as described above, the control of the charging current is at least (1) a control for switching between a predetermined charging current amount and a current amount “0”.
(2) Control to select one of a plurality of predetermined charging current amounts different from each other,
(3) Control to specify the value of the current amount and determine the current amount during charging,
Control one of the above.

The setting unit 31 sets the condition related to the control of the charging current amount and the information of the current amount to be supplied for charging when the condition is satisfied. For example, when the setting unit 31 controls to switch between the above-mentioned (1) predetermined charging current amount and the current amount "0" (when controlling the on / off of the charging current), the charging unit 31 is charged. Stop the current supply. Further, the setting unit 31 sets the upper limit value (for example, "100%") of the charge amount of the secondary battery of the power supply unit 27 and the charge current amount to "0" as a condition for setting the charge current amount to "0". After that, the condition determination unit 32 is set with the lower limit value (for example, "95%") of the charge amount of the secondary battery of the power supply unit 27 as a condition for starting the supply of the charge current corresponding to the charge current amount. Output. In one example of the present embodiment, the set values of the upper limit value and the lower limit value may be accepted by the operation of the operation unit 23 of the user.

Further, when the setting unit 31 controls to select one of a plurality of predetermined charging current amounts different from each other in (2) above, the setting unit 31 is a power supply unit so that any one of the charging current amounts can be selected. The set value of the threshold value of the charge amount of the secondary battery of 27 is output to the condition determination unit 32. This setting, for example, as illustrated in FIG. 3, sets the charging current amount to "0" when the charging amount is "100%", and "does not change" the charging current amount when the charging amount is "95% or more". , When the charge amount is "90% or more and less than 95%", the charge current amount is "I1", the charge amount is "less than 90%", the charge current amount is "I2", and so on. It is performed by instructing the condition determination unit 32 as a data table. This setting may also be changeable by an operation on the operation unit 23 of the user.

Further, when the setting unit 31 specifies (3) the value of the current amount and controls to determine the current amount during charging, the charge amount of the secondary battery of the power supply unit 27 is determined as illustrated in FIG. The charging current amount may be determined by outputting the set value to the condition determination unit 32 so that the charging current amount is determined based on the threshold value. Further, in addition to the charge amount of the secondary battery of the power supply unit 27, or instead of the charge amount of the secondary battery of the power supply unit 27, a set value based on the condition related to the operation of the functional unit of the electronic device 20 is determined. It may be output to the unit 32. Here, the condition relating to the operation of the functional unit of the electronic device 20 may be a condition based on, for example, the load of the control unit 21 (CPU operating rate) or the total power consumption of each unit such as the communication unit 25. For example, if the load of the control unit 21 is "80% or more", the charge current amount may be set to "I2" regardless of the charge amount of the secondary battery of the power supply unit 27.

The condition determination unit 32 determines whether or not the conditions (if there are a plurality of them, any of them) specified by the set value input from the setting unit 31 are satisfied. For example, if the condition specified by the setting unit 31 includes a condition based on the charge amount of the secondary battery of the power supply unit 27, the condition determination unit 32 acquires information on the charge amount of the secondary battery of the power supply unit 27. .. This information is generally acquired from a PMU (Power Management Unit) circuit included in the power supply unit 27. Further, when the condition specified by the setting unit 31 includes information such as a load of the control unit 21 as a functional unit, the condition determination unit 32 acquires information related to the condition.

Then, the condition determination unit 32 examines whether or not the conditions specified by the setting unit 31 (if there are a plurality of them, any of them) are satisfied based on the acquired information, and if there is a satisfying condition, the said condition determination unit 32. Information on the charge current amount associated with the condition is output to the current amount determination unit 33.

For example, when the condition specified by the setting unit 31 outputting the set value to the condition determination unit 32 controls to switch between the above-mentioned (1) predetermined charging current amount and the current amount "0". If the charge amount of the acquired secondary battery of the power supply unit 27 is "100%", the condition determination unit 32 will charge the charging current according to the conditions specified by the setting unit 31. Information to the effect that the amount is set to "0" is output to the current amount determination unit 33.

Further, as another example, when the condition set by the setting unit 31 is the one shown in the above-mentioned example of the condition in which the value of the current amount is specified and the control for determining the current amount during charging is performed. The condition determination unit 32 acquires information on the load of the control unit 21, and if the information is, for example, "85%", the charge current amount is "" regardless of the charge amount of the secondary battery of the power supply unit 27. Information indicating "I2" is output to the current amount determination unit 33.

The current amount determining unit 33 generates a signal for controlling the charging current so that the charging current amount supplied from the charger 10 is the charging current amount represented by the information output by the condition determination unit 32. The signal transmission unit 34 transmits the control signal for setting the charging current generated by the current amount determination unit 33 to the charger 10 via the communication unit 25.

Here, when the charger 10 and the electronic device 20 are connected using Bluetooth (registered trademark) which is a short-range wireless communication means, the signal transmission unit 34 is connected to the charger 10 which has been subjected to the pairing process in advance. On the other hand, a signal for controlling the charging current is sent. When using a wireless LAN, for example, the charger 10 and the electronic device 20 may be connected in a so-called ad hoc mode. In this case, the electronic device 20 sends a signal for controlling the charging current directly to the charger 10 by one-to-one communication.

However, the electronic device 20 acquires or holds information for identifying the charger 10 connected to itself, and sends out a signal for controlling the charging current together with the information for identifying the charger 10, and the charger 10 On the side, if the signal transmitted together with the information for identifying the self is received and used for the process of controlling the charging current, another communication method may be adopted.

Next, the operation of the control unit 12 of the charger 10 and the configuration example of the charge control unit 14 will be described. The operation of the control unit 12 and the configuration of the charge control unit 14 are also
(1) Control to switch between a predetermined charging current amount and a current amount "0",
(2) Control to select one of a plurality of predetermined charging current amounts different from each other,
(3) Control to specify the value of the current amount and set the current amount during charging,
It depends on which control is performed.

First, (1) when a control for switching between a predetermined charging current amount and a current amount "0" is performed, the charge control unit 14 supplies a power supply circuit (FIG. 4) as illustrated in FIG. In the example of 4, it is realized by the switch 51 that connects / disconnects the USB Vbus line). The control unit 12 turns the switch 51 on (a state in which the line is connected) or off (a state in which the line is cut off) according to the instruction received from the electronic device 20.

Specifically, in this example, the control unit 12 turns on the switch 51 when an instruction to supply the charging current amount (instruction to turn on the charging current) is transmitted from the electronic device 20, and supplies the charging current. To be in a state of performing. Further, when an instruction to set the charging current amount to "0" (instruction to turn off the charging current) is transmitted from the electronic device 20, the control unit 12 turns off the switch 51 to supply the charging current. It is in a state of stopping.

By this operation, in the secondary battery of the power supply unit 27 of the electronic device 20, as conceptually illustrated in FIG. 5, the charge amount of the secondary battery is a threshold value on the predetermined upper limit side (for example, "100%"). That is, a predetermined amount of charging current is supplied and charging is performed until the battery becomes fully charged. When the electronic device 20 sends an instruction to the charger 10 that the charging current amount should be "0" when the charging amount reaches the threshold value on the predetermined upper limit side, the control unit 12 sends an instruction to set the charging amount to "0". The switch 51 is turned off. Therefore, the amount of charging current becomes "0" and charging is stopped. After that, until the next charge amount reaches the lower limit (for example, "95%"), the electronic device 20 does not give an instruction, the charge current amount remains "0", and the charge amount becomes the lower limit. When the value drops to the threshold value on the side, the electronic device 20 transmits an instruction to set the charging current amount to a predetermined value. In this example, since the control unit 12 turns on the switch 51 in response to this instruction, charging is restarted from this point.

According to this example of the present embodiment, unlike the charging method performed only by the PMU, when the charge amount drops even a little in order to maintain the charge amount at "100%", the charge is not performed but the charge is fully charged. Since charging is not restarted until the charge amount is sufficiently reduced from the state, the load on the secondary battery included in the electronic device 20 is reduced.

Further, (2) when control for selecting one of a plurality of predetermined charging current amounts different from each other is performed, the charge control unit 14 uses the power supplied from the power supply unit 11 as an example in FIG. Based on this, current supply terminals P1, P2 ..., Pn (n is an integer of 2 or more) that supplies currents having different current amounts (one of which may be "0") and one of them. It is configured to include a switch 52 for selecting one and connecting it to a circuit for supplying power to the power supply unit 15 (USB Vbus line in the example of FIG. 6).

Specifically, in this example, when the instruction to supply the charging current amount is transmitted from the electronic device 20, the control unit 12 supplies a current supply terminal (corresponding to) that supplies the charging current amount instructed by the electronic device 20. If there is no such thing, the switch 52 is controlled so as to connect the circuit for supplying the power of the power supply unit 15 to the current supply terminal) that supplies the minimum amount of current exceeding the minimum current amount.

Further, (3) when the control for setting the charging current amount is performed by designating the current amount value, the charge control unit 14 serves as a memory device (register) as illustrated in FIG. 7. The value memory 55, the current sensor 56, the comparator 57, and the DC / DC converter 58 are included. Further, in this example, the control unit 12 stores the value of the charge current amount designated by the electronic device 20 in the target value memory 55 of the charge control unit 14.

The current sensor 56 detects the amount of current in the circuit that supplies power (USB Vbus line in the example of FIG. 7). Since various circuits for detecting the current in such a circuit can be adopted, the description thereof is omitted here. The current sensor 56 converts the detected current amount value into a digital value using an A / D converter or the like and outputs the value.

The comparator 57 compares the value It of the specified charging current amount stored in the target value memory 55 with the value ID of the amount of current output by the current sensor 56, and if It> ID, the output current. An instruction to reduce the amount is output to the DC / DC converter 58. Further, if It <ID, the comparator 57 outputs an instruction to increase the output current amount to the DC / DC converter 58. The comparator 57 outputs nothing when It = ID.

The DC / DC converter 58 controls the amount of electric power supplied by the power supply unit 11 according to the signal output by the comparator 57. Specifically, this DC / DC converter 58 initially adjusts the current amount of the power supplied by the power supply unit 11 so as to have a value of the charging current amount set in advance, and supplies power to the circuit (Fig.). In the example of 7, it is supplied to the USB Vbus line).

Further, when the comparator 57 outputs an instruction to reduce the output current amount, the DC / DC converter 58 determines the current amount of the electric power supplied by the power supply unit 11 to be more predetermined than the current amount currently supplied. It is adjusted to the amount of current reduced by the value of and supplied to the circuit for supplying power (Vbus line of USB in the example of FIG. 7). When the comparator 57 outputs an instruction to increase the output current amount, the DC / DC converter 58 determines the current amount of the electric power supplied by the power supply unit 11 to be more predetermined than the current amount currently supplied. It is adjusted to the amount of current increased by the value and supplied to the circuit for supplying power (USB Vbus line in the example of FIG. 7).

The charging system of this example of this embodiment operates as follows. In the following example, (3) as a setting in the case of controlling to set the charging current amount by designating the current amount value, in advance.
(A) If the charge amount is "less than 90%", the charge current amount I2 (the maximum current that can be supplied by the charger 10) is specified.
(B) If the charge amount is "90% or more" and the current consumption amount Ir of the functional unit of the electronic device 20 is less than the predetermined threshold value Ith, the charge amount I1 is specified.
(C) If the charge amount is "90% or more", the current consumption Ir of the functional unit of the electronic device 20 is equal to or more than the predetermined threshold value Ith, and I1 + Ir-Ith <I2, the charge current amount is Id. = I1 + Ir-Ith is specified. When I1 + Ir-Ith is I2 or more, Id = I2 is specified as the charging current amount.
It is assumed that the conditions of and are set.

Under the above conditions, when the charger 10 is connected to the electronic device 20 while the user of the electronic device 20 has started, for example, a game application, the control unit 21 of the electronic device 20 changes to the secondary battery of the power supply unit 27. And the total information of the current consumption amount of the functional unit (control unit 21 and other parts) is acquired. Then, it is determined whether or not the acquired charge amount satisfies the previously set condition, that is, (a) whether or not the charge amount is "less than 90%". Here, (a) if the charge amount is "less than 90%", the control unit 21 sends an instruction to specify the charge current amount I2 to the charger 10 via the communication unit 25.

Initially, the charger 10 supplies the electronic device 20 with a charging current having the maximum current amount that can supply the charging current amount I2. Here, upon receiving the instruction for specifying the charging current amount I2, the charger 10 stores the value of the charging current amount I2 in the target value memory 55 of the charge control unit 14. The charger 10 controls itself so that the amount of current output by the DC / DC converter 58 and supplied to the electronic device 20 approaches the designated charging current amount. However, since the charging current amount I2, which is the target value, has already been supplied here, the comparator 57 of the charging control unit 14 does not perform control to change the charging current amount. Therefore, the charger 10 maintains the supply of electric power generated by the charge current amount I2.

When the charge amount becomes "90% or more", the control unit 21 of the electronic device 20 checks the current consumption Ir of the functional unit of the electronic device 20. Here, it is assumed that the user has started the game application, and the current consumption Ir exceeds the predetermined threshold value Ith. In this case, the control unit 21 calculates I1 + Ir-Ith and checks whether the calculated value is less than I2, which is the maximum amount of charging current that can be supplied by the charger 10. Here, if the value obtained by the calculation is less than I2, which is the maximum charge current amount that can be supplied by the charger 10, the control unit 21 gives an instruction to specify Id = I1 + Ir-Ith as the charge current amount. , Is sent to the charger 10 via the communication unit 25.

Upon receiving the instruction, the charger 10 stores the designated charging current amount I1 + Ir-Ith in the target value memory 55 of the charging control unit 14. Here, since the specified charge current amount I1 + Ir-Ith is a smaller value than the charge current amount I2 at that time, the comparator 57 of the charge control unit 14 is a DC / DC converter so as to reduce the output current amount. Instruct 58. This instruction is continued until the amount of current supplied by the DC / DC converter 58 is less than the indicated I1 + Ir-Ith. Further, when the amount of current supplied by the DC / DC converter 58 is less than the indicated I1 + Ir-Ith, this value is smaller than the indicated charging current amount I1 + Ir-Ith, so that the comparator 57 of the charge control unit 14 Instructs the DC / DC converter 58 to increase the amount of output current. This instruction is continued until the amount of current supplied by the DC / DC converter 58 becomes equal to or greater than the indicated I1 + Ir-Ith. Hereinafter, by this control, the amount of charging current supplied by the charger 10 to the electronic device 20 is maintained in a state close to the instructed I1 + Ir-Ith.

According to this example of the present embodiment, while the charge amount is sufficient, charging is not performed by a large current for so-called quick charging, but charging is performed only by the amount of current required by an application program or the like. It will be continued and maintained to the extent that it prevents the charge from decreasing. As a result, the load on the secondary battery included in the electronic device 20 can be reduced.

[Another example of communication method]
In the description of the present embodiment so far, when the charging is not performed, the signal is not exchanged between the power supply unit 15 and the power receiving unit 26 (for example, usually). In the case of USB, the signal is not sent or received according to the standard), and a signal including an instruction related to the amount of charging current is sent and received by another path between the communication unit 13 and the communication unit 25. The form is not limited to this.

For example, among the USB standards, by configuring the circuit according to the ACA (Accessory Charging Adapter) standard, signals can be sent and received even when charging is not performed, so instructions regarding the amount of charging current can be given. The included signal may be transmitted via a cable such as USB, which is a charging cable.

[Correction of current amount indication]
Further, when the circuit is actually assembled according to the above example of the present embodiment, the amount of current supplied to the power supply unit 27 is larger than the amount of current supplied to the power receiving unit 26 due to the characteristics of the power receiving unit 26. May be smaller. In this case, the control unit 12 of the charger 10 sets the charge control unit 14 so as to supply a value of a current amount larger by a predetermined current amount Δi to the charge current amount Id instructed by the electronic device 20. You may control it. Although the amount of current to be added is defined here, the present embodiment is not limited to this, and the charging current amount instructed by the electronic device 20 is Id by defining the ratio α (α> 1) to be increased. Occasionally, the control unit 12 may control the charge control unit 14 so as to supply the current amount of α · Id.

Further, instead of processing by the charger 10 in this way, the charger gives an instruction to specify a value of a current amount larger by a predetermined current amount Δi with respect to the charging current amount Id requested by the electronic device 20. It may be sent to 10. Further, also in this example, instead of determining the amount of current to be added, the ratio α (α> 1) to be increased is determined, and when the amount of charging current to be requested is Id, the electronic device 20 determines α · Id. The instruction to supply the current amount of the above may be sent to the charger 10.

1 Charging system, 10 Charger, 11 Power supply unit, 12 Control unit, 13 Communication unit, 14 Charge control unit, 15 Power supply unit, 20 Electronic equipment, 21 Control unit, 22 Storage unit, 23 Operation unit, 24 Display unit, 25 Communication unit, 26 Power receiving unit, 27 Power supply unit, 31 Setting unit, 32 Condition determination unit, 33 Current amount determination unit, 34 Signal transmission unit, 51 switch, 52 switch, 55 Target value memory, 56 Current sensor, 57 Comparator , 58 DC / DC converter.

Claims (4)

A charging system including a charger and an electronic device charged by the charger.
The electronic device is
With a secondary battery,
A means for charging the secondary battery with the electric power supplied from the charger, and
A functional unit operated by the electric power supplied by the secondary battery, and
A communication means that determines the charging current amount based on the charging amount of the secondary battery and the conditions related to the operation of the functional unit, and sends a control signal for setting the determined charging current amount to the charger. ,
Including
The conditions relating to the operation of the functional unit are the conditions relating to the power consumption of the functional unit.
The charger receives a signal for setting the charging current amount from the electronic device, controls the supply amount of the charging current, and controls the supply amount of the charging current.
In the electronic device, a first threshold value regarding the charge amount of the secondary battery and a second threshold value regarding the power consumption amount of the functional unit are set.
The communication means charges differently when the charge amount of the secondary battery is less than the first threshold value and when the charge amount of the secondary battery is equal to or more than the first threshold value. A charging system that determines the amount of current and , when it is equal to or higher than the first threshold value, determines the amount of charging current based on the conditions using the power consumption amount of the functional unit and the second threshold value . A charger that is connected to an electronic device equipped with a secondary battery and supplies a charging current to the electronic device.
The electronic device is an electronic device in which the amount of current supplied to the power supply unit that supplies power to each part of the electronic device is smaller than the amount of current shared by the power receiving unit that receives power from the charger.
A receiving means for receiving a control signal for setting the charging current amount from the electronic device, and
A supply control means that controls the supply amount of the charging current to the electronic device according to the received signal.
Have,
The control signal received by the receiving means is
In the electronic device, the charge amount of the secondary battery of the electronic device is determined by using the first threshold value regarding the charge amount of the secondary battery and the second threshold value regarding the power consumption amount of the functional unit. When the charge amount is less than the first threshold value and when the charge amount of the secondary battery is equal to or higher than the first threshold value, different charging current amounts are determined and the first threshold value is set. In the above cases, it is a control signal in which the charging current amount is determined based on the condition using the power consumption amount of the functional unit and the second threshold value.
The supply control means is a charger that controls to supply a charge current that is larger by a predetermined amount of current with respect to the charge current amount instructed by the received control signal. The charger according to claim 2 .
The supply control means includes a current output unit having a plurality of terminals for supplying currents having different current amounts from each other.
A switch means for selecting one of a plurality of terminals included in the current output unit according to a signal received from the electronic device and connecting the selected terminal and a current supply terminal to the electronic device.
Charger with. It has a secondary battery that is charged by the power supplied from a charger connected to the outside, and a functional unit that operates by the power supplied by the secondary battery. An electronic device in which the threshold value and the second threshold value regarding the power consumption of the functional unit are set .
A means for acquiring the charge amount of the secondary battery and, as a condition relating to the operation of the functional unit operated by the power supplied by the secondary battery, a means for acquiring the condition relating to the power consumption of the functional unit.
A communication means for transmitting a control signal for setting a charging current to the charger based on the acquired charge amount of the secondary battery and conditions relating to the power consumption of the functional unit.
To function as
The conditions relating to the operation of the functional unit are the conditions relating to the power consumption of the functional unit.
When the secondary battery functions as the communication means, the charge amount of the secondary battery is less than the first threshold value, and the charge amount of the secondary battery is equal to or higher than the first threshold value. In addition to determining different charging current amounts, when the value is equal to or higher than the first threshold value, the charging current amount is determined based on the conditions using the power consumption amount of the functional unit and the second threshold value. A program that works to determine .

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