JPH1132444A - Charger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To finish the charging operation at about the same period of time required for ordinary charging operation by altering the set value of a charging current, control means depending on the fluctuation in the level of charging current generation capacity thereby altering the the charging current value and sustaining the charging operation even when the power of a DC power supply drops below a specified value. SOLUTION: Depending on the charging operation mode of channels ch1, ch2 dependent on the state of the detection voltage values VB1, VB2, the temperature detection value, and the counts of timer functions 2a, 2b, a controller 2 sets/alters charging current set signals Ccil1, Ccil2 such that a desired amount of current is generated. Furthermore, the controller 2 receives an input voltage detection signal Vd from an input voltage detecting section 8 and delivers the charging current set signals Ccil1, Ccil2 for altering the set value depending on the input voltage detection signal Vd. According to the arrangement, the charging operation can be sustained reliably depending on the current charging capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging device that can be used for charging a rechargeable battery (secondary battery) by itself or built in an electronic device.

[0002]

2. Description of the Related Art Generally, a charging device is used alone for charging a rechargeable battery or a charging device built in an electronic device and capable of charging a rechargeable battery mainly used in the electronic device. However, these charging devices use a DC input as a power supply to generate a charging current. For example, when a commercial AC power supply is used as a power supply, the AC power supply is converted and supplied as a DC power supply using a so-called AC adapter, or a DC power supply is obtained by incorporating an AC / DC converter. ing.

[0003]

By the way, in a charging apparatus, one or a plurality of charging circuit systems are usually configured so as to be compatible with one or a plurality of rechargeable batteries, and a rechargeable battery is loaded in a certain charging circuit system. Accordingly, a charging current is supplied to the rechargeable battery. As a charging operation, there is a charging operation in which a charging current amount is changed according to a charging operation state such as a charging state and a time. In any case, when a rated DC power supply (power supply capacity) is supplied, the charging current is changed. It is designed to be able to cover the generation of the maximum charging current in the grid. For example, when using an AC adapter, when designing an AC adapter of 4.5 V and 650 mA output as a standard, the 4.5 V and 65 mA output is required.
Under the supply of 0 mA DC power, the charging operation can be performed with the maximum charging current in each charging circuit system.

However, there are AC adapters that are not standard for the charging device, such as AC adapters having the same terminal structure but having different output powers (for example, AC adapters with 4.5 V and 500 mA output). They can be connected by. in this case,
In some cases, a sufficient charging current cannot be generated, which may result in a longer charging time or, in some cases, disable the charging operation. Also, the AC adapter is as specified, or the AC / DC power supply
Even if the conversion is performed, the charging operation may also be disabled when the effective value of the AC power supply itself is reduced.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, the present invention continues the charging operation even when the power of a DC power supply for generating a charging current becomes lower than a specified value. Even in such a case, it is an object to enable the charging operation to be completed in a time as close as possible to a normal charging time.

For this purpose, the detection means detects the level of the charging current generating capability according to the charging operation status at that time by the power supplied from the external power supply. The control means controls the value of the charging current from the charging current generating means by giving a set value to the charging current control means in accordance with the charging operation status (charging time or charging level), and detects the charging current detected by the detecting means. The value of the charging current from the charging current generating means is changed by changing the set value of the charging current control means in accordance with the fluctuation of the generation capability level. That is, under a certain charging operation condition, it is determined whether or not the power supply at that time has a necessary charging current generating capability, and the charging operation (charging current) is controlled accordingly, so that at least In addition to avoiding charging failure and interruption,
The charging operation with the original charging current is executed in response to the recovery of the charging ability, and the prolongation of the charging time is reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and operation of a charging device according to an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram showing the configuration of the charging device of the present embodiment. A predetermined AC adapter is connected to the power supply terminal 1, and a commercial AC power supply has a rated output of 4.5 V, 650 m, for example.
DC power supply DCin as A is supplied. Of course, when a nonstandard AC adapter is connected or when the effective value of the commercial AC power supply itself is reduced, 4.5 is used.
V, 650 mA DC power supply DCin may not be obtained.

The current I from the DC power supply DCin is supplied to the DC / DC converter 3A as a current I1 and supplied to the DC / DC converter 3B as a current I2.
This charging device has two charging circuits including DC / DC converters 3A and 3B. That is, as a charging circuit system for channel ch1, DC / DC converter 3A generates a charging current I10 to execute a charging operation for rechargeable battery 90 mounted on loading unit 4A. Further, as a charging circuit system for channel ch2, DC / DC converter 3B generates a charging current I20 to execute a charging operation for rechargeable battery 90 mounted on loading section 4B. Each of the channels ch1 and ch2 starts the charging operation in response to the charging of the rechargeable battery 90. The input voltage of the DC power supply DCin is Vin, DC / D
The output voltage of the C converter 3A is V10, DC / DC
The output voltage of the converter 3B is indicated by V20.

The charging current control unit 7 generates control signals PWMa and PWMb, which are PWM modulation signals, according to the signals Cdu1 and Cdu2 for controlling the pulse duty. The values of the charging currents I10 and I20 output from the DC / DC converters 3A and 3B are individually controlled by control signals PWMa and PWMb from the charging current control unit 7. Signal Cdu1 for determining pulse duty of control signal PWMa in charging current control unit 7
Is generated by the charging current detector 5A and the amplifier 6A. The charging current detector 5A performs current / voltage conversion by the resistor R1, and detects the level of the charging current I10 in the channel ch1 as a certain voltage value. Further, a setting value corresponding to a certain current value is set in the charging current detection unit 5A by the charging current setting signal Cci1 from the controller 2. Then, the charging current detecting unit 5A compares the detected current amount of the charging current I10 of the channel ch1 with the current amount set as the set value, generates a signal corresponding to the difference, and outputs the signal according to the difference. Via the signal Cdu1
Is supplied to the charging current control unit 7. Charge current control unit 7
Outputs a control signal PWMa having a pulse duty corresponding to the signal Cdu1 generated in this manner,
By controlling the conversion ratio in converter 3A,
The charging current I10 is controlled to a current amount according to the value of the charging current setting signal Cci1.

The control signal PWM in the charging current control unit 7
Similarly, a signal Cdu2 for controlling the pulse duty of b is generated by the charging current detector 5B and the amplifier 6B for the channel ch2. The charging current detection unit 5B includes:
Current / voltage conversion is performed by the resistor R2 to detect the level of the charging current I20 in the channel ch2 as a certain voltage value, and a setting value corresponding to a certain current value is obtained by the charging current setting signal Cci2 from the controller 2. Is set. Then, the detected current amount of the charging current I20 of the channel ch2 is compared with the current amount set as the set value, a signal corresponding to the difference is generated, and charged as the signal Cdu2 via the amplifier 6B. The current is supplied to the current controller 7. The charging current control unit 7 outputs a control signal PWMb having a pulse duty corresponding to the signal Cdu2 generated in this manner, and controls the conversion ratio of the DC / DC converter 3B, thereby controlling the charging current I20
Is controlled to a current amount corresponding to the value of the charging current setting signal Cci2.

The controller 2 is formed by a microcomputer and controls the entire charging operation of the charging device. The controller 2 includes a resistor R11 and a capacitor C for the rechargeable battery 90 mounted on the channel ch1.
1 to detect the voltage VB1. Accordingly, the progress of charging (charging amount) of the rechargeable battery 90 can be monitored, and when the voltage VB1 is smaller than a predetermined value, it can be determined that the rechargeable battery 90 is not mounted on the loading unit 4A. . Similarly, the controller 2 detects the voltage VB2 of the rechargeable battery 90 mounted on the channel ch2 via the resistor R21 and the capacitor C2. Therefore, the rechargeable battery 90
The charging progress (charging amount) of the battery can be monitored, and when the voltage VB2 is smaller than the predetermined value, it can be determined that the rechargeable battery 90 is not mounted on the loading unit 4B.

The charging operation of each channel is started when a rechargeable battery is loaded. The controller 2 can determine whether or not a rechargeable battery is loaded in each channel by using the voltages VB1 and VB2. Then, the controller 2 instructs on / off of the generation operation of the control signals PWMa and PWMb in the charging current control unit 7 by the signals Cch1 and Cch2. For example, when it is detected that the rechargeable battery 90 is mounted on the loading section 4A, the control signal PWMa is output by the signal Cch1.
Is instructed to start the output of the charging current control section 7, whereby the output of the charging current I10 from the DC / DC converter 3A is started.

The temperature detecting section 10 detects the temperature condition of the rechargeable battery 90 in the loading sections 4A and 4B, and supplies the detected temperature value to the controller 2. The controller 2 has a timer function 2 for counting the time from the start of charging for each channel.
a and 2b. The controller 2 detects the detected voltage value VB1 for the rechargeable battery 90 loaded in the loading section 4A,
Timer function 2a that counts from the time when the charging of channel ch1 is started, the temperature detection value related to loading section 4A
Channel c according to each state of the count value of
Control of the charging operation mode at h1 is performed. The controller 2 also includes a detection voltage value VB2 for the rechargeable battery 90 loaded in the loading unit 4B, a temperature detection value for the loading unit 4B, and a count value of a timer function 2b that counts from the time when charging of the channel ch2 is started. , The charging operation mode in the channel ch2 is controlled. The transition of the charging operation mode will be described later.

The light emitting units 11A and 11B perform a light emitting operation according to the charging operation mode under the control of the controller 2. For example, the light emitting units 11A and 11B are each a red light emitting LED.
And a green light emitting LED. Thereby, each light emitting unit 11
A and 11B are capable of emitting red and green light, respectively, and can present the operating state to the user by the emitted color. The operation state can also be determined and presented based on a light emission method such as a blinking operation and a lighting operation. Then, the controller 2 presents the operation status of the channel ch1 by controlling the emission color and emission method of the light emitting unit 11A. In addition, the operation state of the channel ch2 is presented by controlling the light emission color and light emission method of the light emitting unit 11B.

Further, the controller 2 supplies a charging current setting signal Cci to each of the charging current detecting units 5A and 5B.
1 and Cci2, the charging currents I10,
The current amount of I20 can be controlled. Controller 2
A predetermined amount of current is generated according to the charging operation mode in the channels ch1 and ch2 that changes according to the respective states of the detection voltage values VB1 and VB2, the temperature detection value, and the count values of the timer functions 2a and 2b. Thus, the set value is set / changed by the charging current setting signals Cci1 and Cci2. The input voltage detection signal Vd from the input voltage detection unit 8 is supplied to the controller 2.
Also outputs the charging current setting signals Cci1 and Cci2 for changing the set value according to the input voltage detection signal Vd.

The input voltage detector 8 is constituted by a hysteresis comparator, for example, and compares the input voltage Vin with comparison reference voltages V1 and V2 as shown in FIG. That is, the reference voltage V1 is set as a threshold value for the fluctuation of the input voltage Vin, and the reference voltage V2 is set as a threshold value for the fluctuation of the input voltage Vin. , To the controller 2. The rise of the input voltage detection signal Vd is caused by the DC power supply DCin which satisfies a sufficient capacity (charging current generating ability) to execute charging with one or both of the channels ch1 and ch2 at the time at the original charging current. Is the detection signal of the state where is not supplied,
In addition, the falling of the input voltage detection signal Vd indicates that the DC power supply DCin which satisfies a sufficient capacity for executing the charging operation with the original current amount as the charging operation at that time is restored. Is the detection signal.

The constant voltage circuit 9 is provided with an operating power supply voltage Vc of each unit.
This is a circuit section for generating c. That is, in response to the DC power supply voltage DCin being supplied to the AC adapter connected to the power supply terminal 1, the operating power supply voltage Vcc is supplied to each unit, and the charging device is set to a charging operable state.

The basic charging operation of such a charging device is as follows. In this charging device, channel ch1,
Since the independent charging and independent control are performed by the two charging circuit systems of ch2, respectively, the current I = I1 + I2, and as for the input power (= current I × voltage Vin), I × Vin = (I1 × Vin) + (I2 × Vin) = {(V10 × I10) / η1} + {(V20 × I20) / η2}. Note that η1 is the efficiency of the DC / DC converter 3A, and η2 is the efficiency of the DC / DC converter 3B.

The charging operation is constant-current charging, and the charging current is substantially constant according to the charging operation mode. The charging operation in each channel basically shifts to an initial charging mode, a rapid charging mode, and a trickle charging mode according to the time from the start of charging as shown in FIG. For example, the period from the insertion of the rechargeable battery to the time point t1 (for example, 5 minutes) is set to the initial charging mode, and the charging current during this period is, for example, about 400 mA. Further, for example, a period from time t1 to time t2 (for example, 4 hours after loading the rechargeable battery) is set to the rapid charging mode, and the charging current during this period is, for example, about 650 mA. Further, for example, from time t2 to time t
3 (for example, 6 hours after charging the rechargeable battery), a trickle charging mode is set, and the charging current during this period is, for example, about 50 hours.
mA. The charging current is controlled to be substantially constant at such a current amount according to the charging operation mode. Also, the efficiency η1,
η2 is almost constant.

In consideration of the above-described expression for the input power, the maximum value of the input power (= current I × voltage Vin) is determined by the DC power supply DCin, so that the charging current in the channels ch1 and ch2 increases and the current I increases. Indeed, the input voltage Vin decreases. Therefore, the fluctuation of the input voltage Vin can be regarded as a fluctuation of the charging current generating ability according to the DC power supply DCin at that time and the charging current total amount I (= I1 + I2) to be executed at that time. Then, by detecting the fluctuation of the input voltage Vin by the input voltage detection unit 8 and generating the input voltage detection signal Vd, the controller 2 uses the current DC power supply DCin with power sufficient for the charging operation to be performed. It can be determined whether or not there is. In this example, for example, in the initial charging mode or the rapid charging mode for each channel,
The controller 2 performs the constant charging current generation control according to the mode as described above, and the input voltage detection signal Vd
The change control of the charging current amount according to the control is also performed.

Here, transition of the charging operation mode will be described with reference to FIG. The charging operation mode is channel ch1,
Transitions are made independently at ch2. In a state where the rechargeable battery 90 is not loaded in the loading section 4 (4A or 4B),
The channel is set to the standby mode. At this time, the light emitting unit 11 (11A or 11B) corresponding to the channel is turned off. When the voltage value VB (VB1 or VB2), that is, the terminal voltage of the rechargeable battery becomes, for example, 0.2 V or more, the controller 2 determines that the rechargeable battery 90 is loaded in the channel, and responds to the loaded determination of the rechargeable battery 90. First, the charging operation is performed with the charging current of 400 mA until the count value of the timer (2a or 2b) reaches the time point t1 shown in FIG. 3 as the initial charging mode.

However, in the initial charging mode, for example, 30
If the voltage VB does not reach 0.8 V at the second, the operation is not in a normal state and the mode is switched to the low-voltage charging mode, and the charging current is set to, for example, 60 mA. The voltage VB is monitored even during the low-voltage charging mode, and if the voltage VB exceeds 1 V, the mode returns to the initial charging mode. However, during execution of the low-voltage charging mode, if the voltage VB does not reach 1 V even after reaching the time point t1 (for example, 5 minutes), which is the time-up of the initial charging mode, the mode shifts to the abnormal mode and the light emitting unit 11 flashes red. The light emission is executed and the charging operation is stopped.

When the time of the initial charging mode is up, the voltage VB is in the normal range (overvoltage (for example, 1.7).
0 V) or less and a low voltage (for example, 0.8 V or more), the mode shifts to the quick charging mode, and the charging operation with the charging current of 650 mA is performed. However, when the voltage VB is not within the normal range at the time of the initial charging mode time-up, the mode shifts to the abnormal mode.

The rapid charging mode is performed until the time point t2 (for example, 4 hours from the start of charging) is reached or until -ΔV is detected for the voltage VB. -ΔV detection refers to detection of a phenomenon in which the voltage of the rechargeable battery drops by about ΔV from the peak value and stabilizes when the battery reaches a fully charged state, that is, the state of charge of the rechargeable battery 90 reaches full charge. This is the detection of what has been done. Time-up of the quick charge period, or-
The mode shifts to the trickle charge mode in response to the ΔV detection. In the trickle charging mode, the light emitting unit 11 performs green lighting indicating that charging is completed, and performs a charging operation using a weak charging current of 50 mA. This trickle charge mode is performed until a time t3 (for example, 6 hours from the start of charging) at which the total time is up, and when the time t3 is reached, the mode shifts to the charge termination mode. In the charging end mode, the light emitting section 11 performs green lighting indicating the completion of charging continuously from the trickle charging mode, and sets the charging current to 0 mA. That is, the charging operation is stopped.

In the quick charge mode, the trickle charge mode, and the charge end mode, when an overvoltage or a low voltage is detected as the voltage VB, the mode shifts to the abnormal mode. Also, after charging is started as the initial charging mode,
When a temperature abnormal state is detected, the mode shifts to the abnormal mode. In other words, in the charging operation, when there is a possibility that the rechargeable battery is over-discharged or short-circuited, when there is a possibility that an over-charged state or a dry battery is loaded, or when the temperature is abnormal, the battery enters the abnormal mode and is charged. To stop,
Prevents accidents and alerts the user by flashing red.

When the rechargeable battery 90 is removed from the charging end mode, the operation returns to the standby mode. In the abnormal mode, when the rechargeable battery 90 is removed or the total time is up, the process returns to the standby mode.

In such a mode transition, a basic charging operation is performed. In addition, in the initial charging mode and the rapid charging mode, a change control of the charging current based on the input voltage detection signal Vd may be performed. . The processing of the controller 2 for executing the charging operation in such a mode transition will be described with reference to FIGS.

Step F100 of FIG. 5 shows the state of the standby mode. If the voltage VB1 detects that the rechargeable battery 90 has been loaded into the loading section 4A of the channel ch1 in step F101, the process proceeds to step F1.
02, the charging operation in channel ch1 is started. Further, as step F201, the fact that the rechargeable battery 90 has been loaded into the loading section 4B of the channel ch2 indicates the voltage VB2.
, The charging operation in channel ch2 is started. Note that the charging operation is performed independently for the channels ch1 and ch2, but the control contents of the controller 2 are the same.
Only 1 will be described.

In step F102, a charging operation start process is performed. That is, while instructing the charge current control unit 7 to start outputting the control signal PWMa by the signal Cch1,
The timer 2a starts counting. Light emitting unit 1
In 1A, red lighting is performed. First, in order to perform charging in the initial charging mode, in step F103, the charging current detection unit 5A receives the charging current setting signal Cci1.
, A set value corresponding to a current of 400 mA is set.
Thereby, the charging current detecting unit 5A generates a signal Cdu1 corresponding to the comparison between the charging current I10 and the set value, supplies the signal Cdu1 to the charging current control unit 7, and sets the pulse duty of the control signal PWMa. Thereby, the DC / DC converter 3
Since the conversion operation of A is controlled, constant current control by a so-called feedback system is performed.
Initial charging is performed in which a charging current I10 of 400 mA is supplied to the rechargeable battery 90.

This initial charging is performed until the count value of the timer 2a reaches t1 in step F108. During that time, monitoring of the input voltage detection signal Vd is performed in steps F104 and F105, and the temperature detection unit 1 is determined in step F106.
Monitoring of temperature information from 0 is performed.

In step F104, the input voltage detection signal Vd
The case where the rise of (see FIG. 2) is detected means that the supplied DC power supply DCin is in a state where there is no sufficient current generating capability for a charging operation performed by the charging device for some reason. means. For example, there are causes such as a decrease in the execution value of the commercial AC power supply voltage, connection of a nonstandard AC adapter, and an increase in the total charging current in the channels ch1 and ch2. In this case, since the charging operation cannot be continued as it is, the controller 2 proceeds to step F10.
Proceeding to 9, the set value in the charging current detection unit 5A is switched to a low value by the charging current setting signal Cci1. That is, the amount of the charging current I10 is reduced. And step F
Step F104 until a positive result is obtained in 105
In the loop of F108, the initial charging with the charging current I10 lower than usual is performed.

At this time, if the initial charging or the rapid charging is being performed also in the channel ch2, the process of the channel ch2 also proceeds to the process corresponding to the step F109 or the step F124, and the charging current setting signal is output. The value set in the charging current detector 5B is also switched to a lower value by Cci2, and the charging current I
20 is reduced. By switching the charging current in accordance with the change in the charging capability of the input power, charging can be continued without interruption.

On the other hand, the case where the fall of the input voltage detection signal Vd is detected in step F105 means that the supplied DC power supply DCin has sufficient current generating capability for the charging operation performed at that time. It means that it has returned to the state. For example, there are causes such as a recovery of the execution value of the commercial AC power supply voltage and a decrease in the total charging current required for the channels ch1 and ch2. In this case, since it is no longer necessary to continue the charging current reduction process performed in step F109 at a time before that, the process returns to step F103 to obtain the original charging current amount in the initial charging mode. That is, the set value in the charging current detection unit 5A is returned to the original value in the initial charging mode by the charging current setting signal Cci1. Thereby, the charging operation returns to the normal initial charging operation.

If a temperature abnormality is confirmed in step F106, the process proceeds to step F115 to shift to the abnormality mode as described in FIG. 4, in which the charging operation is stopped and the light emitting unit 11A is caused to flash red.

In step F107, the timer 2a
Is monitored to reach t0 (for example, 30 seconds). At this point, the process once proceeds to step F110. In step F110, it is checked whether or not the voltage VB1 has reached the low voltage VL (for example, 0.8 V), and if it has, the initial charging mode operation is continued as it is. However, if the voltage VB1 has not reached the low voltage VL, the process proceeds to step F111 and shifts to the low voltage charging mode described with reference to FIG. That is, the value set in the charging current detection unit 5A is changed to a value for the low-voltage charging mode by the charging current setting signal Cci1, and charging is performed at a charging current of 60 mA, for example.

During the low voltage charging mode, step F
At 112, it is monitored whether the voltage VB1 has reached a predetermined voltage VLL (for example, 1 V). When the voltage VB1 has reached the predetermined voltage VLL, the process returns to step F103 and returns to the initial charging mode. However, if the count value of the timer 2a reaches t1, that is, the time to end the initial charging mode without the voltage VB1 reaching the predetermined voltage VLL, it is determined that the state is abnormal, and the process proceeds to step F115.
To the abnormal mode processing.

The operation in the initial charging mode is performed in step F10.
The process ends when the count value of the timer 2a reaches t1 in step 8, but at this time, it is checked in step F114 whether the voltage VB1 is within the normal range. That is, if the voltage VB1 is a value between the low voltage VL and the overvoltage VH, it is determined that the voltage VB1 is normal, but if the voltage VB1 is any other value, it is assumed that there is a possibility of a dry battery, a short / overdischarged battery, an overcharged battery, or the like. Step F
The process proceeds to an abnormal mode process at 115.

In the case of the normal state, as shown as "FC1" in the figure, the flow shifts to step F116 in FIG. 6 to start the operation in the quick charge mode. Here, in order to perform charging in the rapid charging mode, the charging current setting signal C
A set value corresponding to a current of 650 mA is set in the charging current detection unit 5A by ci1. Thereby, the charging current detecting unit 5A generates a signal Cdu1 corresponding to the comparison between the charging current I10 and the set value, and supplies the signal Cdu1 to the charging current control unit 7,
The pulse duty of the control signal PWMa is set. By controlling the conversion operation of the DC / DC converter 3A, constant current control is performed.
Rapid charging in which a charging current I10 of mA is supplied to the rechargeable battery 90 is performed.

This rapid charging is performed in step F122 at -Δ
V detection is performed or until the count value of the timer 2a reaches t2 in step F123, during which the input voltage detection signal V is detected in steps F119 and F120.
Monitoring for d is performed. In step F121, the temperature information from the temperature detector 10 is monitored. Further, in steps F117 and F118, whether the voltage VB1 is in the normal range is also monitored. In step F117, the voltage VB1 is compared with the voltage value Vdb for determining that the battery is a dry cell.
As shown as "3", the process proceeds to the abnormal mode process of step F115 in FIG. In step F117, the voltage VB
It is monitored whether 1 is in a value between the low voltage VL and the overvoltage VH, which is regarded as a normal range, and if it is detected that the value is not in this range, as shown as "FC3", the step F115 in FIG. To the abnormal mode processing. Further, when an abnormal temperature is confirmed in step F121, the process proceeds to step F121.
The process proceeds to the abnormal mode processing of 115.

In step F119, the input voltage detection signal Vd
The case where the rising of (see FIG. 2) is detected means that the supplied DC power supply DCin generates a sufficient current for some reason for the charging operation performed by the charging device, similarly to the case of the step F104. It means that you have no ability. In this case, since the charging operation cannot be continued as it is, the controller 2 advances the process to step F124, and switches the setting value of the charging current detection unit 5A to a low value by the charging current setting signal Cci1. That is, the amount of the charging current I10 is reduced. Then, in a loop of steps F117 to F123 until a positive result is obtained in step F120, rapid charging with a charging current I10 lower than usual is performed.

At this time, if the initial charge or the rapid charge is also being performed in the channel ch2, the process in the channel ch2 is also performed in step F.
The process proceeds to the process corresponding to 109 or step F124, and the value set in the charging current detection unit 5B is also switched to a low value by the charging current setting signal Cci2, and the current amount of the charging current I20 is reduced. As in the case of step F104, even during the rapid charging operation, the charging can be continued without interruption by switching the charging current according to the change in the charging capability of the input power.

On the other hand, the case where the fall of the input voltage detection signal Vd is detected in step F120 means that the supplied DC power supply DCin has sufficient current generating capability for the charging operation performed at that time. Since it has returned to the state, there is no need to continue the charging current reduction process performed in step F124 before that time.
Therefore, the process returns to step F116 to obtain the original charge current amount in the rapid charge mode. That is, the set value in the charging current detection unit 5A is returned to the original value in the rapid charging mode by the charging current setting signal Cci1. As a result, the charging operation returns to the normal quick charging operation.

The operation in the rapid charging mode is performed in step F12.
When the count value of the timer 2a reaches t2 in step 3, or when -V is detected as the voltage VB1 before that, the process ends when the fully charged state of the rechargeable battery 90 is recognized.
Then, as shown as "FC2", step F1 in FIG.
Proceeding to 25, the trickle charge mode operation is started. In step F125, in order to perform charging in the trickle charging mode, a setting value corresponding to a current of 50 mA is set in the charging current detection unit 5A by the charging current setting signal Cci1. Thereby, the charging current detecting unit 5A generates a signal Cdu1 corresponding to the comparison between the charging current I10 and the set value, supplies the signal Cdu1 to the charging current control unit 7, and sets the pulse duty of the control signal PWMa. And this gives DC /
By controlling the conversion operation of the DC converter 3A, constant current control is performed, and trickle charging in which a charging current I10 of 50 mA is supplied to the rechargeable battery 90 is performed. At this time, control is performed to switch the lighting state of the light emitting unit 11A to the green lighting state.

This trickle charge is performed until the count value of the timer 2a reaches t3 in step F128, during which time the temperature information from the temperature detector 10 is monitored in step F127, and the voltage VB1 in step F126 is normal. It monitors whether it is within the range. And F
If it is detected at 126 that the voltage VB1 is not a value between the low voltage VL, which is within the normal range, and the overvoltage VH, or if an abnormal temperature is confirmed at step F127, the process proceeds to step F115 in FIG. Proceed to abnormal mode processing.
The count value of the timer 2a is set to t without shifting to the abnormal mode processing.
When the number reaches 3, the end mode processing is performed in step F129, and the end of the charging operation and the control of the green lighting state of the light emitting unit 11A are performed.

The charging is performed by the above processing. However, as described in steps F109 and F124, the charging current amount is switched according to the input voltage detection signal Vd, so that when an AC adapter of a non-standard is connected, The charging operation can be continued even when the effective value of the AC power supply decreases. In addition, when the performance by the input power is relatively recovered, the charging is returned to the normal charging current amount, so that sufficient charging can be performed in the normal charging time as much as possible.

FIG. 8 shows an example of the charging operation by the charging device of this embodiment. FIG. 8 shows a current I10 and a voltage V10, which are outputs of the DC / DC converter 3A, as a channel ch1.
As the channel ch2, the current I20 and the voltage V20, which are the outputs of the DC / DC converter 3B, the input voltage Vin,
9 shows a transition example of the input charging current I (= I1 + I2). For example, when the rechargeable battery 90 is loaded in the channel ch1 at the time point TM1, the initial charging is performed in the channel ch1, and accordingly, the current I10 is set to the initial charging current amount, and the voltage value V10 fluctuates as illustrated. When the initial charging is completed, the process proceeds to the rapid charging mode, in which the current I10 is set to the rapid charging current amount, and the voltage value V10 also fluctuates as illustrated. During this time, the input charging current I has a value corresponding to the amount of current in the initial charging and rapid charging of the channel ch1, and since the input power is constant, the input voltage Vin decreases as the transition from initial charging to rapid charging occurs. .

Here, it is assumed that a rechargeable battery is also loaded in channel ch2 at a certain time point TM2 while quick charging is being performed in channel ch1. Then channel ch2
, The current I20 is set to the initial charging current amount, and the voltage value V20 fluctuates as shown in FIG. In addition, the sum of the charging current of each channel (I1
+ I2) also increases, and the input voltage V
in drops. If it is assumed that the channel ch2 shifts to the rapid charging at the time point TM3, control is performed to generate a current I20 of, for example, 650 mA in the initial channel ch2. Is done. Here, when there is no capacity to generate such current due to insufficient capacity of the AC adapter supplying the DC input power DCin or insufficient voltage of the AC power supply, it appears as a decrease in the input voltage Vin, and a predetermined reference value is obtained. It will be lower than V1.
As a result, as described with reference to FIG.
Since d rises and the controller 2 performs control to reduce the charging current, the current I10,
The current amount as the current I20 is set to a small value, and the charging operation in both channels is continued.

Thereafter, for example, at time TM4, channel ch
When -ΔV at 1 is detected and the rapid charging is terminated, the value of the current I10 is set to, for example, about 50 mA as trickle charging. Assuming that the level of the input voltage Vin returns to a value exceeding the reference value V2 due to a decrease in the value of the current I at this time, it is not necessary to continue the rapid charging with a small amount of current in the channel ch2. Is set to the original current amount (for example, 650 mA). Then, for example, at time TM5, the channel ch
2, -ΔV is detected, and the channel ch2 also shifts to trickle charging, and the value of the current I20 is set to, for example, about 50 mA.

By controlling the charging current by the operation as shown in FIG. 8, for example, the interruption of the charging operation itself can be avoided. Note that, as an example of the embodiment, an example of an independent two-channel charging device has been described, but it is needless to say that the present invention can be implemented in a charging device having a charging circuit system of one channel or three or more channels. Further, the numerical values (charging current value, mode switching time, comparison reference voltage value such as overvoltage / low voltage, etc.) in the description of the embodiment are merely examples, and these are optimized values when designing the actual charging device. It is set. Further, the operation of the present invention is not limited to the mode transition and the processing procedure described above. For example, in the above example, the charging current change control according to the input voltage detection signal Vd is performed in the initial charging mode and the rapid charging mode, but may be performed also in the trickle charging mode, or Alternatively, it may be executed only in the quick charge mode. Although the charging current change is performed based on the input voltage detection, the charging current change processing may be performed by determining the charging current generating ability from the value of the input charging current I.

[0050]

As described above, the charging device according to the present invention detects the level of the charging current generating ability according to the charging operation status at that time by the power supplied from the external power supply, and the control means controls the charging operation. By changing the set value of the charging current control means and changing the value of the charging current from the charging current generating means in accordance with the fluctuation of the current generating capacity level, the charging operation according to the charging capacity at that time can be continued. It is possible to reliably charge the battery. In addition, by flexibly responding to the charging operation status and the power supply power and performing the optimal charging operation possible at that time, it is possible to prevent the charging operation from being unnecessarily prolonged.

The detecting means detects a decrease in the charging current generating ability by comparing the power level with the first reference value.
Further, by detecting the recovery of the charging current generation ability by comparing the power level with the second reference value, it is possible to perform a detection operation suitable for the charging operation status. Further, the control means responds to the detection of the decrease in the charging current generation capability level,
The set value for the charging current control means is changed so that the value of the charging current is reduced, and the set value for the charging current control means is changed to the set value corresponding to the charging operation status in response to the detection of the recovery of the charging current generation ability. By doing so, the most appropriate charging current control is realized.

Also, in the case where a plurality of charging current generating means are provided, the charging current control means and the controlling means control the amount of charging current in each charging current generating means so that the power supply power at that time is controlled. Even if the charging current generation capability of the system cannot cover the operation of the charging current generating means of all the systems, the charging operation of each system can be continued by reducing the charging current of each system. .

[Brief description of the drawings]

FIG. 1 is a block diagram of a charging device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation of an input voltage detection unit according to the embodiment.

FIG. 3 is an explanatory diagram of a charging operation mode according to the embodiment.

FIG. 4 is a diagram illustrating a transition of a charging operation mode according to the embodiment.

FIG. 5 is a flowchart of a charging operation process according to the embodiment.

FIG. 6 is a flowchart of a charging operation process according to the embodiment.

FIG. 7 is a flowchart of a charging operation process according to the embodiment.

FIG. 8 is an explanatory diagram of an operation example of the charging device of the embodiment.

[Explanation of symbols]

1 Power supply terminal, 2 controller, 3A, 3B DC /
DC converter, 4A, 4B loading section, 5A, 5B charging current detecting section, 7 charging current control section, 8 input voltage detecting section, 10 temperature detecting section, 11A, 11B light emitting section, 90
Rechargeable battery

Claims (3)

[Claims] A charging current generating means for generating a charging current from electric power supplied from an external power supply to perform a charging operation on a mounted rechargeable battery; and a charging current generated by the charging current generating means. Charge current control means capable of performing constant current control in accordance with a set value, detection means for detecting a level of a charge current generation capability based on power supplied from an external power supply, and charge current control in accordance with a charge operation state. Means for controlling the value of the charging current from the charging current generating means by giving a set value to the means, and changing the set value of the charging current control means in accordance with the level fluctuation detected by the detecting means. A charging device, comprising: control means capable of changing the value of the charging current from the current generating means. 2. The detecting means detects a decrease in a charging current generation capability level by comparing the power level with a first reference value, and detects a charging current generation by comparing the power level with a second reference value. The control means is configured to detect a recovery of the capacity, and the control means changes a set value to the charge current control means so as to decrease the value of the charge current in response to the detection of the decrease in the charge current generation ability level. And performing control to return a set value for the charge current control means to a set value according to a charging operation state at that time in response to detection of recovery of the charge current generation capability level. The charging device as described. 3. A charging system comprising a plurality of charging current generating means, wherein the charging current controlling means individually controls a charging current for each charging current generating means, and wherein the controlling means comprises: The charging device according to claim 1, wherein individual setting values relating to the charging current control unit are provided to the charging current control unit.