JPH07182071A - Battery driven type device and power supply control method - Google Patents

Abstract

PURPOSE:To effectively utilize the power supply voltage for driving at the time of connecting a battery pack to an AC adapter terminal in a battery driven type device provided with the AC adapter terminal for charging. CONSTITUTION:When the battery pack is connected to an adapter terminal 13, a voltage detection circuit 21 outputs detection signals S1 for indicating the connection of the battery pack to a NAND circuit 22 based on the voltage level of the voltage signals ADP1 of the adapter terminal 13. Thus, charging permission signals CCUR1 are turned to a disabled state, a charging permission switch 23 is turned off and a charging operation to the battery pack 15 is inhibited. Also, the voltage signals ADP1 at the time are supplied to a CPU 24 which is a driving circuit. Thus, the CPU 24 is operated with the power supply voltage of the battery pack 15 as a driving source.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to battery-operated equipment including a rechargeable battery such as a toy or the like, including a portable personal computer and a word processor, and particularly to an AC adapter connection terminal for charging. The present invention relates to a battery-operated device having the same and a power supply control method thereof.

[0002]

2. Description of the Related Art Conventionally, for example, a battery-driven personal computer or word processor has a built-in secondary battery such as a nickel-cadmium battery and is configured to perform various processes by using the secondary battery as a drive source. . Such a battery-driven device usually has an AC adapter terminal, and the AC adapter is connected to the AC adapter terminal to charge the secondary battery.

In addition to this AC adapter, there is a member for charging a secondary battery called a battery pack. A primary battery such as a dry battery is stored in this battery pack, and the secondary battery is charged through an AC adapter terminal for originally connecting the AC adapter. Since such a battery pack can easily supply power to the secondary battery at any time and at any place, a measure for improving the operation time is provided especially for portable devices whose main purpose is battery operation. Has become a very effective means.

[0004]

As described above, the AC
In a battery-driven device in which an AC adapter or a battery pack can be connected to the adapter terminal, similar charging control has been conventionally performed regardless of what is connected to the AC adapter terminal. That is, when the capacity of the secondary battery is insufficient, rapid charging is performed, and trickle charging is performed even after the completion of charging.

However, unlike the AC adapter, the battery pack has a limited battery capacity. Therefore, if the same charge control as when the AC adapter is connected is performed, the trickle charge is continuously performed despite the completion of charging the secondary battery, and as a result, the capacity of the battery pack is wasted. It will be consumed.

Further, when the secondary battery is charged, a loss corresponding to that occurs, so that when the device is driven, the capacity of the battery pack cannot be used 100% effectively, and particularly the operation of the battery is mainly used. The portable device has a problem such as a malfunction.

The present invention has been made in view of the above points. When the battery pack is connected to the AC adapter terminal,
An object of the present invention is to provide a battery-driven device and a power supply control method that can effectively use the power supply voltage for driving.

[0008]

The battery-powered device of the present invention is a battery-powered device having a built-in secondary battery, for connecting an AC adapter or a battery pack for charging the secondary battery. A connection terminal, a charging unit that supplies the voltage of the connection terminal to the secondary battery for charging, a detection unit that detects that the AC adapter or the battery pack is connected to the connection terminal, and this detection unit. And a power supply control means for prohibiting the charging operation by the charging means and switching the power supply voltage of the battery pack for driving, when the means detects that the battery pack is connected. .

[0009]

According to the above construction, when the battery pack is connected to the connection terminal, the charging operation for the secondary battery is prohibited and the power supply voltage at that time is switched for driving.
As a result, when the battery pack is connected, it is possible to prevent the capacity from being wasted, and moreover, it is possible to eliminate the loss due to charging and use it effectively for driving.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an external configuration of a battery-driven device according to an embodiment of the present invention. In FIG. 1, 1
Reference numeral 1 denotes an apparatus main body, and a secondary battery 12 such as a nicad battery is built in the apparatus main body 11. The battery-driven device is configured to perform various processes by using the secondary battery 12 as a drive source.

Here, the apparatus main body 11 is provided with an adapter terminal 13 for connecting the AC adapter 14, and the AC adapter 14 is arbitrarily attached to the adapter terminal 13. This AC adapter 14
Is for converting a household power supply voltage (alternating current) into a voltage (direct current) necessary for this device. Here, the adapter terminal 13 is used.
Is used as a power source for charging the secondary battery 12 and for driving the device.

A battery pack 15 can also be connected to the adapter terminal 13. This battery pack 15
The battery pack accommodates a plurality of dry batteries, and is originally connected to the adapter terminal 13 and used as a power source for charging the secondary battery 12. However, in the present invention, it is used as a device driving power source.

FIG. 2 is a diagram showing the configuration of a power supply control circuit provided in the apparatus main body 11. This power supply control circuit is composed of a quasi-constant current type circuit, and has a terminal voltage of the adapter terminal 13, a terminal voltage of the secondary battery 12, and a charging current limiting resistor R
1 determines the charging current to the secondary battery 12.

Here, in the embodiment, the voltage detection circuit 2
1, a charge control circuit including a NAND circuit 22 and a charge permission switch 23 is provided, and the adapter terminal 13
When the battery pack 15 is connected to, the charging operation is prohibited.

The voltage detection circuit 21 detects the voltage signal ADP1 from the adapter terminal 13, determines based on the voltage level that the AC adapter 14 or the battery pack 15 is connected to the adapter terminal 13, and shows the result. The detection signal S1 is output to the NAND circuit 22. Here, AC
Since the output voltage of the adapter 14 is 12V and the output voltage of the battery pack 15 is 9V, the connection type is determined using 10V as the threshold value.

The NAND circuit 22 receives the charge permission signal CCUR1 from the CPU 24 and the detection signal S1 from the voltage detection circuit 21, and outputs a signal obtained by taking the negative logical product thereof to the charge permission switch 23 as the charge control signal S2. To do. The charging permission signal CCUR1 is output from the CPU 24 as a signal for permitting charging of the secondary battery 12 when the AC adapter 14 or the battery pack 15 is connected to the adapter terminal 13.

The charge permission switch 23 is a transistor T
The NAND circuit 22 is composed of r1, resistors R2 and R3.
ON / OFF operation is performed based on the charge control signal S2 output from the adapter, and when turned on, the voltage signal A of the adapter terminal 13
DP1 is supplied to the secondary battery 12.

Further, in this embodiment, the adapter terminal 13 is used.
In order to supply the voltage signal ADP1 of not only to the secondary battery 12 but also to the CPU 24 which is a drive circuit, the adapter terminal 1
A power supply path from 3 to the CPU 24 is provided. In the figure, D1 and D2 are backflow prevention diodes.

Next, the operation of the embodiment will be described with reference to the flow chart shown in FIG. The AC adapter 14 or the battery pack 1 is attached to the adapter terminal 13 of the device body 11.
5 is connected, the charge permission signal CCU from the CPU 24
R1 is output and the secondary battery 1 built in the device body 11
Charging to 2 is permitted (step A1). At this time,
The voltage level of the voltage signal ADP1 at the adapter terminal 13 is detected by the voltage detection circuit 21, and it is determined whether the one connected to the adapter terminal 13 is the AC adapter 14 or the battery pack 15 (step A2). ).

In this case, the voltage detection circuit 21 has a voltage of 10V.
When the voltage signal ADP1 exceeds the threshold value, the AC adapter 14 (12V) is connected and the "H" level detection signal S1 is output.

When the AC adapter 14 is connected to the adapter terminal 13, that is, from the voltage detection circuit 21 to "H".
When the level detection signal S1 is output (No in step A3), the charge permission switch 23 is turned on by the "L" level charge control signal S2 output from the NAND circuit 22. As a result, the voltage signal ADP of the adapter terminal 13
1, that is, the power supply voltage of the AC adapter 14 is supplied to the secondary battery 12 to be charged (step A4). In this case, rapid charging is performed when the capacity of the secondary battery 12 is insufficient, and trickle charging is continuously performed after completion of charging.

The voltage signal ADP1 at this time is also given to the CPU 24 which is a drive circuit. This gives C
The PU 24 operates using the power supply voltage of the AC adapter 14 as a drive source (step A5).

On the other hand, the battery pack 15 is attached to the adapter terminal 13.
Is connected, that is, when the detection signal S1 of "L" level is output from the voltage detection circuit 21 (Yes in step A3), the charge permission signal CCUR1 is disabled by the NAND circuit 22, and the charge permission switch 23 Turns off. As a result, the power supply path from the adapter terminal 13 to the secondary battery 12 is cut off, and the charging operation by the voltage signal ADP1 of the adapter terminal 13, that is, the charging operation by the power supply voltage of the battery pack 15 is prohibited ( Step A6).

Further, since the power supply path from the adapter terminal 13 to the CPU 24 is provided, the voltage signal ADP1 at this time is given to the CPU 24 which is a drive circuit.
As a result, the CPU 24 operates using the power supply voltage of the battery pack 15 as a drive source (step A7).

As described above, when the battery pack 15 is connected to the adapter terminal 13, charging of the secondary battery 12 is prohibited, and the power supply voltage is used for driving the CPU 24. Therefore, when the battery pack 15 is connected, it is possible to prevent the capacity from being wasted, and moreover, it is possible to eliminate the loss due to charging and effectively use it for driving.

[0026]

As described above, according to the present invention, it is detected that the battery pack is connected to the connection terminal, the charging operation for the secondary battery is prohibited, and the power supply voltage at that time is used for driving. Since the switching is performed, it is possible to prevent the capacity of the battery pack from being wasted, and moreover, it is possible to eliminate the loss due to charging and effectively use it for driving. As a result, it is possible to improve the operation time, for example, in a portable personal computer, a word processor, or the like, particularly in a portable device whose main operation is a battery.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external configuration of a battery-driven device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a power supply control circuit of the same embodiment.

FIG. 3 is a flowchart for explaining the operation of the embodiment.

[Explanation of symbols]

11 ... Device body, 12 ... Secondary battery, 13 ... Adapter terminal, 14 ... AC adapter, 15 ... Battery pack, 21 ... Voltage detection circuit, 22 ... NAND circuit, 23 ... Charging permission switch, 24 ... CPU.

Claims (3)

[Claims] 1. A battery-powered device having a built-in secondary battery, comprising: a connection terminal for connecting an AC adapter or a battery pack for charging the secondary battery; and a voltage of the connection terminal for the secondary battery. Charging means for supplying the battery to charge it, detecting means for detecting that the AC adapter or the battery pack is connected to the connection terminal, and detecting that the battery pack is connected by the detecting means. In the case of the above, a battery drive device comprising: a power supply control means for prohibiting the charging operation by the charging means and switching the power supply voltage of the battery pack for driving. 2. A battery-driven device having a built-in secondary battery, wherein a connection terminal for connecting an AC adapter or a battery pack for charging the secondary battery, and the AC adapter or the connection terminal for the connection terminal. When the battery pack is connected, a signal output unit that outputs a charge permission signal, and the voltage of the connection terminal is supplied to the secondary battery based on the charge permission signal output from the signal output unit. Charging means for charging, voltage detecting means for detecting the voltage of the connection terminal and outputting a detection signal indicating that the AC adapter or the battery pack is connected from the voltage level, and the voltage detecting means When the output detection signal indicates the connection of the battery pack, the charging permission signal is set to the disable state to prohibit the charging operation by the charging means. And a power supply means for supplying the voltage of the connection terminal to the drive circuit when the charging of the secondary battery is prohibited by the charge prohibiting means. Mold device. 3. A power supply control method for a battery-driven device having a connection terminal for connecting an AC adapter or a battery pack, and a charging means for supplying the voltage of the connection terminal to a secondary battery for charging. In, when the AC adapter or the battery pack is connected to the connection terminal, a charge permission signal is output, the voltage of the connection terminal is detected, and the AC adapter or the battery pack is connected from the voltage level. When the detection signal indicates that the battery pack is connected, the charging permission signal is disabled so that the charging operation by the charging means is prohibited, and the voltage of the connection terminal is changed. A power supply control method characterized in that the power is supplied to a drive circuit.