JPH09130981A - Charge control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always hold charged voltage of a battery at a charge stop voltage. SOLUTION: When voltage of a battery 8 decreases to set a mover to a charger for charging, a microcomputer 6 turns on the first/second changeover switches 3, 4 and turns off the third changeover switch 5, so that a charge current is supplied to the battery 8 and the mover, that is, a portable device control circuit 7 through a protecting diode 2 by external input voltage. When completion of charging is detected by the microcomputer 6, it turns off the first/second changeover switches 3, 4 also turns on the third changeover switch 5, the current by the external input voltage is supplied only to the mover, that is, the portable device control circuit 7, so as to suppress consumption of the battery 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charging control device which is provided in a mobile device such as a mobile phone or a portable wireless device and performs constant voltage charging control on a battery in the mobile device.

[0002]

2. Description of the Related Art Generally, a battery in a mobile unit is automatically charged by setting the mobile unit in a charger. FIG. 3 shows a configuration of a charge control device provided in a conventional mobile unit. Reference numeral 101 denotes a charging control device, which includes a protection diode 102 for an external input voltage from the charger and a changeover switch 1 for turning on / off a charging current.
03 and a microcomputer 104 for controlling the on / off of the changeover switch 103. The microcomputer 104 is a part of the constituent elements of the portable device control circuit 105 in the mobile device. 1
Reference numeral 06 is a battery in the mobile unit, which is charged by the charge control device 101.

When the voltage of the battery 106 drops and the mobile unit is set in the charger for charging, the microcomputer 104 turns on the changeover switch 103 and charges the battery 106 via the protection diode 102 by the external input voltage. Supply current. The battery 106 is charged so as not to exceed 4.1 V, and when the charging current becomes 100 mA or less, the microcomputer 104 detects it and turns off the changeover switch 103 to complete the charging. When the charging is completed and the supply of the charging current is stopped, the standby operation of the mobile unit or the like is the current supply from the battery 106. When the battery voltage falls below a certain level, the microcomputer 104 detects it and turns on the changeover switch 103 again to restart charging.

FIG. 4 shows the transition of the battery voltage of the battery 106 during charging by setting such a mobile unit in the charger. When the battery voltage reaches the charge stop voltage due to charging, the charging is stopped, and when the battery voltage returns to the charge return voltage, the charging is restarted and the battery voltage is controlled within a certain range.

However, in the above-described conventional charge control device, when the mobile unit is set in the charger and the standby operation is performed, the current is supplied from the battery 106 during that period. The battery voltage gradually decreases, and depending on the timing of picking up the mobile unit from the charger, the battery voltage may be on the verge of reaching the charge return voltage. In that case, the battery voltage is low and the battery charging rate becomes insufficient. was there.

The present invention solves such a conventional problem, and an object of the present invention is to provide an excellent charge control device capable of always maintaining the charge voltage of a battery at a charge stop voltage.

[0006]

In order to achieve the above object, a charging control device according to the present invention supplies an external input voltage to a battery and a mobile unit during battery charging, and supplies the external input voltage after completion of battery charging. Since the battery is supplied only to the mobile device, the battery voltage can be always kept at the charge stop voltage regardless of the timing of picking up the mobile device from the charger.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION According to the first aspect of the present invention, an external input voltage is supplied to a battery and a mobile unit during battery charging, and an external input voltage is supplied only to the mobile unit after completion of battery charging. The charging control device is provided with the means, and the battery voltage can always be maintained at the charging stop voltage regardless of the timing of picking up the mobile device from the charger.

According to a second aspect of the present invention, the first switching means for turning on the battery during charging and supplying current to the battery and the mobile unit by the external input voltage, and the first switching switch are provided. The second switching means is provided in the latter stage and supplies current to the mobile unit by the external input voltage, and is provided in the preceding stage of the first switching means, and is turned on when charging of the battery is completed. The present invention is provided with a third switching means for supplying current only to the mobile device and a control means for controlling ON / OFF of each switching device. With a simple device structure, the timing for picking up the mobile device from the charger is set. Regardless of this, the battery voltage can always be kept at the charge stop voltage.

(Embodiment) FIG. 1 shows an embodiment of the present invention. In FIG. 1, 1 is a charge control device, 2 is a protection diode against an external input voltage from a charger, 3 is a first changeover switch for supplying current to a battery and a mobile device by the external input voltage, and 4 is a first switch. Is provided between the output side of the change-over switch 3 and the portable device control circuit 7, and supplies a current to the mobile unit by an external input voltage.
The changeover switches 5 are provided between the input side of the first changeover switch 3 and the portable device control circuit 7, and are turned on when charging of the battery is completed, and current is supplied only to the mobile unit by an external input voltage. A third changeover switch 6 for carrying out the operation is a microcomputer as a control means for controlling ON / OFF of each changeover switch 3, 4, 5. The microcomputer 6 is a part of the components of the portable device control circuit 7 in the mobile device. 8 is a charging control device 1
Is a battery in the mobile that is charged by.

Next, the operation of the above embodiment will be described. When the voltage of the battery 8 drops and the mobile unit is set in the charger for charging, the microcomputer 6 turns on the first and second changeover switches 3 and 4, and turns off the third changeover switch. A charging current is supplied to the battery 8 and the portable device control circuit 7, that is, the mobile device through the protection diode 2 by an external input voltage. The battery 8 is charged so that it does not exceed 4.1 V, and when the charging current becomes 100 mA or less, the microcomputer 6 detects it and turns off the first and second changeover switches 3 and 4 to turn off the battery 8. Complete charging. At the same time, the third changeover switch 5 is turned on to supply a current according to the external input voltage to the portable device control circuit 7, that is, the mobile device. Therefore, when the charging is completed and the supply of the charging current is stopped, the current required for the mobile unit such as the standby operation is supplied by the external input voltage, so that the current of the battery 8 is not consumed and the battery voltage is lowered. Never.

FIG. 4 shows the transition of the battery voltage of the battery 8 during charging by setting such a mobile unit in the charger. When the battery voltage reaches the charge stop voltage due to charging, the battery voltage will not drop as long as the mobile unit is set in the charger.

As described above, according to the above-described embodiment, after the battery is charged, the current required for the mobile unit is supplied by the external input voltage. Therefore, the battery voltage is irrespective of the timing of picking up the mobile unit from the charger. Can always be kept at the charge stop voltage.

[0013]

As is apparent from the above embodiment, the present invention supplies the external input voltage to the battery and the mobile unit while charging the battery, and supplies the external input voltage only to the mobile unit after the battery charging is completed. As a result, the battery voltage can always be kept at the charge stop voltage regardless of the timing of picking up the mobile unit from the charger.

[Brief description of the drawings]

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

FIG. 2 is a characteristic diagram showing changes in battery voltage during charging according to an embodiment of the present invention.

FIG. 3 is a schematic block diagram showing a configuration of a charge control device in a conventional example.

FIG. 4 is a characteristic diagram showing changes in battery voltage during charging in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Charge control device 2 Protective diode 3 First changeover switch 4 Second changeover switch 5 Third changeover switch 6 Microcomputer 7 Portable device control circuit 8 Battery

Claims (2)

[Claims] 1. A charge control device comprising means for supplying an external input voltage to a battery and a mobile unit during charging of a battery and supplying the external input voltage only to the mobile unit after completion of battery charging. 2. A first switching means which is turned on during charging of the battery and supplies a current to the battery and the mobile unit by an external input voltage, and an external input voltage which is provided after the first switching switch. Second to supply current to the mobile unit by
And a third switching means which is provided before the first switching means, is turned on when the battery is completely charged, and supplies current only to the mobile unit by the external input voltage, and each of the switching means. The charging controller according to claim 1, further comprising a control unit that controls ON / OFF of the unit.