JPH04244741A - Battery-drives electric equipment - Google Patents

Abstract

PURPOSE:To provide a battery-drives electric equipment in which a plurality of batteries can be efficiently used. CONSTITUTION:A controller 6 detects whether corresponding secondary batteries 1A, 1B are mounted at battery connecting terminals 4A, 4B or not according to detected voltages of voltage detectors 12, 13. If the detected voltage of the battery 1A is larger than a predetermined voltage, the controller 6 turns ON only a transistor 10. The battery 1A is discharged by a circuit 2 through the transistor 10 and a power source switch 3. If the voltage of the battery 1A is lowered to a predetermined voltage, the controller 6 turns OFF the transistor 10, and turns ON a transistor 11 corresponding to the battery 1B. The battery 1B is discharged by the circuit 2 through the transistor 11 and the switch 3.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to battery-powered electrical equipment to which a plurality of batteries can be detachably attached.

0002

2. Description of the Related Art FIG. 4 shows a conventional circuit configuration in which two secondary batteries 1A, 1B can be installed.
1B, a power switch 3 that turns on and off the main circuit 2, a battery connection terminal 4A that connects the first secondary battery 1A, and a battery connection terminal 4A that connects the power switch 3. diode 5 connected between and the second 2
A battery connection terminal 4B that connects the next battery 1B, diodes 7 and 8 connected between this battery connection terminal 4B and the power switch 3, and a voltage dividing resistor 9 that divides the battery voltage applied to the main circuit 2. and a control unit 6 that monitors the battery voltage and displays an indication when the voltage falls below a predetermined voltage.

[0003] Here, a case will be described in which the secondary battery 1A is connected to the battery connecting terminal 4A and the secondary battery 1B is connected to the battery connecting terminal 4B. First, when the power switch 3 is turned on,
Battery voltage is applied to the main body circuit 2. Since there is one diode 5 between the secondary battery 1A and the power switch 3, the voltage applied to the main circuit 1 at this time is VA (voltage of the secondary battery 1A) - VF (saturation voltage of the diode).

On the other hand, since there are two diodes 7 and 8 between the secondary battery 1B and the power switch 3, the main circuit 2
The applied voltage at is VB (voltage of secondary battery 1B) - 2 x VF
becomes. Therefore, when the battery voltages of the secondary batteries 1A and 1B are the same voltage, discharge starts from the secondary battery 1A first, the voltage of the secondary battery 1A decreases by the saturation voltage VF, and the VA
When -VF=VB-2×VF, voltage is supplied from both secondary batteries 1A and 1B.

[0005] As described above, by utilizing the difference in the saturation voltage of the diodes, the secondary battery 1A is preferentially discharged, and when it is discharged to a predetermined voltage, a charging reminder display can be made.

[0006]

However, in recent battery-powered electrical equipment, particularly portable personal computers, etc., a plurality of batteries are replaced in sequence and used continuously. However, in the above conventional example, the secondary battery 1B is connected to the main circuit 1.
Since the battery can only be discharged to a voltage that is 2×VF higher than the driveable voltage of the secondary battery 1B, while the secondary battery 1B is being discharged,
When A is replaced, the discharge shifts to the secondary battery 1A again, and if this replacement operation is repeated, when the charging reminder display for the secondary battery 1A is displayed, the secondary battery 1B will also reach the charging reminder display level at the same time. As a result, there was a risk that continuous use would not be possible.

Therefore, after the secondary battery 1B is used up, the replaced secondary battery 1A is discharged again, and during that time, the secondary battery 1A is discharged again.
This means that it is more efficient to charge B and replace it. Further, in the conventional example, it is not known which secondary battery A has no amount of 1BNO. The present invention has been made in view of the above points, and an object of the invention as claimed in claim 1 is to enable efficient use of a plurality of batteries by sequentially discharging them to a low voltage level. The purpose of the present invention is to provide a battery-powered electric device that can be used with batteries.

[0008] In addition to the object of the above-mentioned claim 1, it is an object of the invention as claimed in claim 2 to provide a battery-driven electric device in which the remaining capacity of each battery can be finally used without waste. is to provide.

[0009]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the invention as claimed in claim 1 provides a method in which a plurality of batteries are detachably attached and each battery is connected in parallel to a load via a diode. In a battery-powered electrical device that discharges batteries in parallel, a switch element connected in parallel to each diode, a voltage detection section connected between each battery and the diode, and one of the switch elements to which the batteries are connected are connected. When one switch element is turned on to discharge the battery through this switch element, and the corresponding voltage detection unit detects that the battery voltage of the battery has fallen below a predetermined voltage, the battery is connected. The battery is equipped with a control section that turns off a switch element and turns on a switch element to which another battery is connected.

The invention according to claim 2 is the invention according to claim 1, in which all the switch elements are turned on when all the installed batteries become lower than a predetermined voltage.

[0011]

[Operation] According to the present invention, the control section detects whether or not the corresponding battery is installed based on the detected voltage of each voltage detecting section, and when the detected voltage is larger than a predetermined voltage, the control section detects whether or not the corresponding battery is installed. When one switch element is turned on and the battery connected to this switch element is discharged, and the voltage of this battery drops to a predetermined voltage, the control unit turns off the switch element that is currently on, and responds to another battery. Turn on the switch element to discharge another battery. In this way, the batteries can be sequentially discharged to a predetermined voltage.

In the invention as claimed in claim 2, when all the batteries are discharged to a predetermined voltage, the switch elements corresponding to all the batteries are turned on, so that the capacity remaining in each battery can be discharged. can.

[0013]

[Examples] The present invention will be explained below with reference to Examples. FIG. 1 shows a circuit configuration of an embodiment of the present invention, and this embodiment has a diode 5 and a transistor 1 in the conventional example of FIG.
0 are connected in parallel, and a switch element consisting of a transistor 11 is connected in parallel to the diode 7, and instead of the voltage dividing resistor 9, a voltage dividing resistor is connected to each of the battery connection terminals 4A and 4B. The voltage detection units 12 and 13 are connected to detect the voltages of the corresponding secondary batteries 1A and 1B.

The control unit 6 is composed of a CPU, etc., and controls the transistors 10 and 11 based on the detected voltages of the voltage detection units 12 and 13, and also controls the transistors 10 and 11, which are provided corresponding to the secondary batteries 1A and 1B to be installed, respectively. Charging reminder display (
(not shown). Next, the operation of one embodiment will be explained based on the flowchart of FIG.

First, when the power switch 3 is turned on, the control unit 6 resets the charging reminder display for the secondary batteries 1A, 1B, and also resets the flag indicating that the secondary batteries 1A, 1B are being discharged. Further, transistors 10 and 11 are set to the off state. Next, after the initial settings, the control unit 6 checks whether the detected voltage of the voltage detection unit 12 corresponding to the first secondary battery 1A is zero, and determines whether the secondary battery 1A is installed. judge.

[0016] If the detected voltage of the voltage detecting section 12 is not zero but 2
When the secondary battery 1A is installed, the control unit 6 turns on the transistor 11 corresponding to the secondary battery 1B based on the discharging flag of the second secondary battery 1B written in the internal memory, and the secondary battery 1B is discharged. Check if it is inside. 2
When the discharging flag of the secondary battery 1B is in the reset state and is not discharging, the control unit 6 checks the state of the charging reminder display of the secondary battery 1A.

When the charging reminder display of the secondary battery 1A is reset and the discharge is not yet completed, the control unit 6 turns on the transistor 10, turns off the transistor 11, and resets the discharging flag of the secondary battery 1A. do. Next, the control unit 6 compares the voltage detected by the voltage detection unit 12, that is, the voltage of the secondary battery 1A, and the preset charging reminder voltage VD, and determines whether the voltage of the secondary battery 1A is higher than the charging reminder voltage VD. When it is small, a display reminding you to charge the secondary battery 1A is displayed, and
Reset the discharging flag of the next battery 1A.

When the secondary battery 1A is not installed, the control unit 6 resets the charging reminder display of the secondary battery 1A, turns off the transistor 10, and resets the discharging flag of the secondary battery 1A. . Next, the control section 6 checks whether the voltage of the second secondary battery 1B is zero based on the detected voltage of the voltage detection section 13. This voltage detection section 1
When the detected voltage of No. 3 is not zero and the secondary battery 1B is installed, the transistor 10 is turned on based on the discharging flag of the secondary battery 1A to check whether it is discharging.

If the discharging flag of the secondary battery 1A is in the reset state and it is discharging, the control section 6 checks the state of the charging reminder display of the secondary battery 1B. When the charging reminder display of the secondary battery 1B is reset and the discharge is not yet completed, the control unit 6 turns on the transistor 11 and turns off the transistor 10, and sets the discharging flag of the secondary battery 1B.

Next, the control unit 6 compares the voltage detected by the voltage detection unit 13, that is, the voltage of the secondary battery 1B, with a preset charging reminder voltage VD, and the voltage of the secondary battery 1B is determined to be the charging reminder voltage. When the voltage is lower than VD, a display to remind the secondary battery 1B to charge is performed, and the discharging flag of the secondary battery 1B is reset. When secondary battery 1B is not installed,
The control unit 6 resets the charging reminder display of the secondary battery 1B, turns off the transistor 11, and
The discharging flag of B is reset, and the process returns to the determination of attachment of the first secondary battery 1A.

As described above, when both the secondary batteries 1A and 1B are installed, the secondary battery 1A installed first can be discharged to the charging reminder voltage VD, and then the secondary battery 1B installed can be discharged. Similarly, the battery can be discharged to the charging reminder voltage VD. When the charging reminder voltage VD is reached, a charging reminder display can be performed for each of the secondary batteries 1A and 1B. Further, for example, when the secondary battery 1A is replaced, the transistor 10 is turned on again after the discharge of the secondary battery 1B is completed, and the secondary battery 1A can be discharged.

By the way, in the process shown in the flowchart shown in FIG. 2, when all of the installed secondary batteries 1A and 1B reach the charging reminder voltage VD, only the transistor corresponding to the secondary battery that was last discharged is turned on. Discharged. Further, the charging reminder voltage VD is at the charging reminder warning level, and there is still some capacity remaining. Therefore, the capacity of the secondary battery corresponding to the transistor that is not turned on remains.
It becomes unusable.

[0023] Therefore, all the installed secondary batteries 1
In this embodiment, when the voltages of A and 1B reach the charge prompting voltage VD, the transistors 10 and 12 are turned on so that the remaining capacity of both can be used. In this embodiment, the circuit configuration is the same as that in FIG. 1, but in the flowchart of FIG. 2, when the charging reminder display for the secondary battery 1B is set,
This is an additional process in which the control unit 6 checks whether the charging reminder display A has already been set, and if it has been set, turns on both transistors 10 and 11.

Accordingly, when the secondary batteries 1A, 1B reach the charge urging voltage VD, the transistors 10, 11 are turned on, and the remaining capacity of both the secondary batteries 1A, 1B can be used.

[0025]

[Effects of the Invention] The invention as claimed in claim 1 provides a battery-driven electric device in which a plurality of batteries are removably installed, each battery is connected in parallel to a load via a diode, and each battery is discharged in parallel. A switch element connected in parallel to the diode, a voltage detection section connected between each battery and the diode, and a switch element to which the battery is connected are turned on. to discharge the battery, and when the corresponding voltage detection unit detects that the battery voltage of the battery has become below a predetermined voltage,
Since the controller is equipped with a control unit that turns off a switch element to which the battery is connected and turns on a switch element to which another battery is connected, it is possible to sequentially discharge a plurality of batteries to a low voltage level. As a result, the battery can be used more efficiently.

[0026] Furthermore, the invention according to claim 2 is such that in the invention according to claim 1, when all the installed batteries become lower than a predetermined voltage, all the switch elements are turned on. In addition to the effects of the above invention, there is an effect that the remaining capacity of each battery can be used without waste.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram showing one embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of an embodiment of the present invention.

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

FIG. 4 is a circuit block diagram of a conventional example.

[Explanation of symbols]

1A Secondary battery 1B Secondary battery 2 Main circuit 3 Power switch 4A Battery connection terminal 4B Battery connection terminal 5 Diode 6 Control section 7 Diode 10 Transistor 11 Transistor 12 Voltage detection section 13 Voltage detection section

Claims (2)

[Claims] Claim 1: A switch element connected in parallel to each diode in a battery-driven electric device in which a plurality of batteries are removably installed and each battery is connected in parallel to a load via a diode to discharge each battery in parallel. Then, the voltage detecting section connected between each battery and the diode, and the switch element to which the battery is connected, turn on only one switch element to discharge the battery through this switch element, and discharge the battery through this switch element. A control unit that turns off a switch element to which the battery is connected and turns on a switch element to which another battery is connected when the corresponding voltage detection unit detects that the battery voltage of the battery has fallen below a predetermined voltage. A battery-powered electrical device characterized by comprising: 2. The battery-powered electric device according to claim 1, wherein all switch elements are turned on when all the installed batteries become lower than a predetermined voltage.