JPH01103127A - Secondary battery charging equipment - Google Patents

Abstract

PURPOSE:To prevent charge control from being discriminated in error, by stopping quick charge when the current of a set value or more for adapter output flows, and by executing the quick charge again when current is reset to come to the set value. CONSTITUTION:When current greater than a set value flows during quick charge, then signal is transmitted to a charge controlling circuit 20 from an adapter current detecting circuit 17. While the input of the signal is provided, retained storage content is cleared by a charge peak voltage storing circuit 19, and at the same time, storage working is interrupted, and by a charge total time timer circuit 22, count working is also interrupted. Then, a charge current controlling circuit 18 is set in the state of supplementary charge, and charge current flowing to a secondary battery 14 is reduced, and battery voltage is dropped, but control working is not performed by the charge controlling circuit 20. When adapter output current comes to the set value or less again, then quick charge working signal is transmitted to a charge current controlling circuit 17 from the charge controlling circuit 20, and the quick charge is re- started, and the count working of the charge time total timer circuit 22 is re-started.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a secondary battery charging device that includes a built-in secondary battery charging control circuit used for charging secondary batteries and also has an adapter output (DC output). It is.

BACKGROUND OF THE INVENTION In recent years, secondary batteries such as sealed nickel-cadmium batteries (cadmium batteries) and lead-sealed batteries have been widely used as power sources for portable videos and hand belt combiators. A charging device with an adapter output (DC output) is cited as an external power source for such a device with a built-in secondary battery.

Hereinafter, the operation of the conventional charging device with an adapter output as described above will be explained with reference to the drawings.

FIG. 4 shows a control circuit using a manual switch as an output switching method of a conventional charging device with an adapter output.

In Figure 4, 1 is A that converts AC input to DC constant voltage.
C/DC converter 2 is a manual switch that switches the output from converter 1 to adapter output 4 or charging control circuit 3;
6 is a charging control circuit that controls charging current to charging output 5;
7 is a load such as an electrical device connected to the adapter output terminal 4, and 7 is a secondary battery connected to the charging output terminal 5.

The operation of the above circuit will be explained below.

In this circuit, when operating an electrical device 6 connected to the adapter output terminal 4, by connecting the changeover switch 2 to the a contact, the output from the mu C/DC converter 1 is connected to the adapter output 4, and the electrical device Operating power is applied to 6. When charging the secondary battery 7 connected to the charging output 5, charging power is applied to the charging output 5 via the charging control circuit 3 by switching the switch 2 to the B contact. Charging becomes possible. In other words.

By switching the switch 2, the user can switch the operation of the charging device with adapter output.

- Fig. 5 is an example of a circuit that enables parallel output as an output method of a conventional charging device with an adapter output.

In Figure 6, 8 is A that converts AC input to DC constant voltage.
A C/DC converter, 9 a charging control circuit that controls the charging current to the charging output 11, and 12 a load such as an electrical device connected to the adapter output 1o.

13 is a secondary battery connected to the charging output 11.

In this circuit, the adapter output 1o and the charging control circuit 9.
Since the charging output 11 is always connected to the AC/DC converter 8, by using a high-output human C/DC converter, the electrical equipment 12 connected to the adapter output 1° and Secondary battery 1 connected to charging output 11
Charge 3 at the same time.

Problems to be solved by the invention In recent years, power supplies with a charging function for electrical devices with built-in secondary batteries have been developed.
There are increasing demands for rapid charging, automation of operation switching, and miniaturization of devices.

With the above circuit configuration, a manual switch is required to switch between adapter output and charging operation.

Types without a changeover switch have the disadvantage that the AC/DO converter becomes quite large because the adapter output and charging output are used simultaneously.

In view of the above drawbacks, the current flowing to the adapter output is detected during charging, and if the current exceeds the set value, quick charging is stopped, and when the adapter output current returns to within the set value range, quick charging is resumed. The present invention proposes a secondary battery charging device with an adapter output, which has a built-in secondary battery charging control circuit that prevents malfunctions in charging control due to changes in the battery state accompanying the control.

Means for Solving the Problem In order to achieve this object, the charging device with an adapter output of the present invention includes a circuit for detecting the completion of charging, a circuit for detecting the DC output current of the adapter during charging, and a circuit for detecting the DC output current of the adapter during charging. The battery is comprised of a circuit that varies the charging current based on the signal received, and a circuit that prevents charging control from malfunctioning due to changes in the battery state due to changes in the charging current.

Effect: With this configuration, when a current exceeding a set range flows through the adapter output during charging by the circuit of the present invention, the charging current control is varied to stop rapid charging, and the full charge detection is accordingly set to 0FFL, and the adapter output current is set to 0FFL. When it returns to within the set value range again, rapid charging is performed again, and the automatic output switching function with the function to prevent misjudgment of charging control is performed by making the accompanying full charge detection non-detection. will have.

Embodiment 1 As an embodiment of the present invention, a circuit in which a drop in battery voltage at full charge is utilized for rapid charge control will be described with reference to the drawings.

Figure 1 shows a charging control means that completes charging when the quick charging current flows for a specified time, a charging control means that completes charging when the battery voltage drops by more than a set value from the peak value during charging, and a charging control means that completes charging when the battery voltage drops by more than a set value from the peak value during charging. means for detecting the adapter output current;
This figure shows the circuit configuration of a secondary battery charging device with an adapter output, which has means for varying charging current control based on a detected signal.

In FIG. 1, reference numeral 14 denotes a secondary battery that is charged by the charging circuit via the charging output 24. 15 is a load such as an electric device driven by the current from the adapter output 26. 16
is a circuit that detects the battery voltage during charging. 17 is a circuit for detecting the outflow current to the adapter output. 18 is a circuit that controls the charging current. Reference numeral 19 denotes a storage means for storing the battery voltage during charging. 2o is a charging control circuit that generates a signal to the charging current control circuit based on each detection signal. 21 is a timer circuit for extending the OFF period of the battery voltage storage operation.

22 is a timer circuit for terminating quick charging when the quick charging current has flowed for a specified time.

23 is a MuC/DC that converts the MuC input voltage into a DC constant voltage.
It is a converter.

Next, the operation will be explained.

First, connect the discharged secondary battery 14 as shown in FIG.
The output from the system 0/DO converter is connected to the charging output 24 via the charging current control circuit 18, and charging is started. If the DC output current of the adapter does not flow during rapid charging, the characteristics of battery voltage and charging current will be as shown in FIG. This means that if the value detected by the battery voltage detection circuit 16 increases during rapid charging, the charging control circuit 20 always sends the latest value sent from the battery voltage detection circuit 16 to the charging peak voltage storage circuit 19. While storing the data, a signal is given to the charging current control circuit 18 so that the charging current control circuit performs a constant current charging operation. Then, constant current charging is continued by the action of the charging current control circuit 18. Thereafter, when the battery voltage begins to drop at the end of charging, the charging peak voltage storage circuit 19 retains the maximum value up to that point. The charging control circuit 2o constantly compares the value held in the charging peak voltage storage circuit 19 with the value from the battery voltage detection circuit 16, and as the battery voltage continues to drop, the value from the battery voltage detection circuit 16 changes. When the current exceeds the set value from the value held in the charging peak voltage storage circuit 19, the signal to the charging current control circuit 18 changes from quick charging (large current) operation to supplementary charging (small current) operation. to complete quick charging (-ΔV control)
.

Also, during the above quick charging operation, for some reason,
When the battery voltage at the end of charging does not drop by the set amount, the charging total time timer circuit 22 works to reduce the charging current to the supplementary charging current value after charging for a specified time.

(Total timer control) Next, a case where the adapter output current flows out during rapid charging will be explained.

In FIG. 3, the operation during normal rapid charging is the same as described above. During quick charging, the load 16 is connected to the adapter output 25, and the set value (
When a current larger than X5at, ) flows, a signal is transmitted from the adapter current detection circuit 17 to the charging control circuit 2o. During the period when this signal is input (between T and -T2), the charging peak voltage storage circuit 19 clears the stored memory contents and at the same time interrupts the storage operation as shown in FIG. Charging total time timer circuit 2 like
2 also interrupts the counting operation. Then, a signal for performing supplementary charging (small current) operation is given to the charging current control circuit 1, and the circuit enters the supplementary charging state. At this time, the charging current flowing to the secondary battery 14 rapidly decreases, so the battery voltage vB drops as shown in FIG. , the charging control circuit 2o is −Δ
No V control operation. Furthermore, even if the adapter output current continues to flow at or above the set value for a long time, the charging total timer circuit 22 temporarily suspends its operation as shown in Fig. 3C, so the total timer control may be activated. There isn't.

Again, the adapter output current decreases and the set value (■get,
) or below and the signal from the adapter current detection circuit is switched, the charging current control circuit 1 is switched from the charging control circuit 2o.
7, a signal for quick charging (large current) operation is transmitted to restart quick charging, and the counting operation of the charging time total timer circuit 22 restarts. However, for a while after the restart ( between Tz and Ts) is
Due to the function of the voltage memory off timer circuit 21, the
The storage operation of the charge peak voltage storage circuit 19 continues to stop as shown in FIG.
Start memory operation. Therefore, when the adapter current decreases and the charging current suddenly increases from the auxiliary charging current (small current) to the quick charging current (large current), the battery voltage vB suddenly increases in a short period of time as shown in the turtle in Figure 3. However, this phenomenon is unique to rechargeable batteries. As mentioned above, due to the function of the voltage memory off timer circuit 21, T
Since the storage operation of the charging peak voltage storage circuit 19 is stopped between z and 'rs, the charging control circuit 2o does not perform the -ΔV charging control operation. Therefore, malfunction of the 1 ΔV charge control operation at the time of restarting quick charge is prevented. A series of time charts are shown in FIG.

With the above-described operation, even if the charging current is repeatedly interrupted during rapid charging, full charging is possible through accurate charging control operation. Also, in this example.

16.19, 20, 21.22 in FIG. 1 were realized by a microcomputer. Note that it is also possible to use other charging control methods instead of -ΔV charging control.

Effects of the Invention As described above, the present invention detects the DC output current of the adapter during charging, controls and varies the charging current when the output current is detected, and suspends rapid charging.
AC/Do converter), it is possible to perform regular full charging while automatically switching the output operation.
Its practical effects are significant.

For example, if you write down a specific numerical example, if the adapter output of 1 µm output and the quick charge output of 1 µm are simultaneously driven in parallel,
The power supply requires 2 µm output, but according to Honjitsu, 1 µm output is required.
In other words, since the output of the power supply becomes A, the power supply can be made smaller and lower in cost.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the charging device with adapter output of the present invention, and FIG. 2 is a charging current-battery voltage characteristic diagram during basic charging control of the secondary battery charging control circuit of the present invention. FIG. 3 is a characteristic diagram illustrating the operation of an embodiment of the secondary battery charging device with an adapter output according to the present invention, and FIGS. 4 and 5 are block diagrams showing conventional examples of the charging device with an adapter output. 1.8.23...Mu C/Do converter, 2...
. . . Means for switching the output of the MU0/Do converter to the adapter output or charge control circuit, 3.9 . . . Secondary battery charging control circuit, 4, 10.28 . . . Adapter Output terminal, 5, 11.24...Charging output terminal, 6゜12.15...Load such as electrical equipment connected to adapter output terminal, 7+ 13, 14...
...Secondary battery connected to the charging output terminal, 16...
...Battery voltage detection circuit, 17...Adapter current detection circuit. 18...Charging current control circuit, 19...
Charging peak voltage storage circuit, 20... Charging control circuit, 21... Voltage storage off timer circuit, 22
...Charging total timer circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person
2 Figure 4 Figure 5

Claims (3)

[Claims] (1) A battery voltage detection unit connected to both ends of the battery, a charging control unit that detects any phenomenon of the battery that occurs during rapid charging and completes charging, and a current detection unit that detects the DC output current of the adapter; output control means that suspends rapid charging of the battery when the adapter current detected by the current detection flows beyond a set value, and performs quick charging again when the adapter output current decreases again below the set value. A rechargeable battery charging device. (2) The output control means stops detecting the battery status while the adapter's DC output current exceeds the set value and stops rapid charging, and when it returns to rapid charging from that state, charging is not terminated within a certain period of time. The secondary battery charging device according to claim 1, characterized in that the device does not operate. (3) It has a timer operation function that terminates quick charging when the quick charging current flows through the secondary battery for a certain period of time, and when the adapter output current flows beyond the set value by the output control means and the quick charging is suspended, the timer operates to count. 2. The secondary battery charging device according to claim 1, wherein the counting operation is resumed when the charging mode is temporarily stopped and the rapid charging mode is resumed from that state.