JPH10232272A - Detector for battery residual capacity and radio calling receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery residual capacity detector and radio calling receiver for effectively utilizing a battery by correctly displaying a battery residual capacity even in the case of the battery having different voltage characteristics. SOLUTION: An MPU 11 periodically turns ON a switching circuit 14, applies a load 15 to a battery 4, calculates a differential coefficient ΔX from a difference of digital signals input from an A-D converter 13 corresponding to a drop amount of a voltage signal of the battery 4 before or after the application of the load 15, and displays the corresponding residual capacity while comparing the coefficient ΔX with a preset threshold value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery level detecting device for detecting and displaying the remaining battery level in a portable device such as a pager or a portable telephone, and a radio paging receiver. Also, the present invention relates to a battery remaining amount detecting device and a radio paging receiver capable of correctly detecting the remaining amount.

[0002]

2. Description of the Related Art A battery generally used in a portable device is a manganese battery. The voltage characteristic of the battery is as shown in FIG. 3 (a). It is characterized in that a voltage drop occurs in this case.

[0003] On the other hand, with the spread of portable devices in recent years, there has been an increasing number of users who desire to extend the specifiable time, and high-capacity batteries such as air batteries and alkaline batteries are increasingly used. The voltage characteristics of such a high-capacity battery are different from those of a manganese battery, as shown in FIG. The feature is that the voltage drops.

[0004] A conventional battery remaining amount detecting device will be described with reference to FIG. FIG. 4 is a configuration block diagram of a conventional battery remaining amount detection device. As shown in FIG. 4, a conventional battery remaining power detection device includes an A / D converter 1, an MPU 2, an RO
It is basically composed of an M3, a battery 4, and a display unit 5.

[0005] Hereinafter, each part will be described in detail. The A / D converter 1 converts a voltage signal supplied from the battery 4 into a digital signal and outputs the digital signal to the MPU 2.
The MPU 2 refers to the ROM 3 using a digital signal input from the A / D converter 1 as an address, and displays the remaining battery level on the display unit 5 according to a value stored in the address.

In the ROM 3, a signal indicating the remaining battery level corresponding to the digital signal corresponding to the voltage signal is set in advance.
It is stored. Here, the digital signal and the signal indicating the remaining battery level are, for example, in accordance with the voltage characteristics of the manganese battery shown in FIG.
In accordance with the digital signal corresponding to the voltage signal larger than the voltage signal at point A in (a), "3" is stored as a signal indicating the remaining battery level, and the digital signal corresponding to the voltage signal at points A and B is stored. In response to the signal, “2” is stored as a signal indicating the remaining battery level, and thereafter, “1” is used from point B to point C, and “0” is used below point C.

In this case, when the signal indicating the remaining battery level of the MPU 2 is "3", for example, a display as shown in FIG.
As shown in FIG. 5 (b) to FIG.
It is conceivable that the display as shown in (d) is performed.

Next, the operation of the conventional battery remaining power detecting device will be described. First, when a new manganese battery is used as the battery 4, the digital signal output from the A / D converter 1 is equivalent to a voltage signal sufficiently larger than the point A. Is read out, the signal becomes "3", so that the display unit 5 displays as shown in FIG. 5A.

When the battery 4 eventually runs out, A / D
Since the digital signal output from the converter 1 corresponds to the voltage signal between the points A and B, the MPU 2 performs the display as shown in FIG. 5B, and so on. 5 (c) to 5 (d), and the battery 4 completes discharging.

When a high-capacity battery such as an alkaline battery is used as the battery 4, the digital signal output from the A / D converter 1 corresponds to the voltage signal between the points A and B in FIG. 3 in a short time. After that, the voltage signal is held until immediately before the discharge is completed.
U2 continues to display on the display unit 5 as shown in FIG. 5B until immediately before the discharge is completed.

Immediately before the completion of discharge, A / D
The digital signal output from the converter 1 is A
From the equivalent of the voltage signal between points B and B,
Point, and the MPU 2 displays on the display unit 5 as shown in FIG.
The battery 4 completes discharging with little time to perform the display as shown in (c) to (d).

[0012]

As described above, in the conventional battery remaining amount detecting device, when batteries having different voltage characteristics, such as high capacity batteries, are used, the remaining battery amount cannot be displayed properly. There was a problem.

When the conventional battery level detecting device is employed in a device having a memory for storing a message or the like such as a pager, when the battery level is sufficient to protect the contents of the memory. Some devices have a so-called low battery voltage warning device (LVA) that issues an alarm and prompts the user to replace the battery. In this case, however, the battery cannot be used to the end, and the battery cannot be used effectively. there were.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a battery remaining amount detecting device and a radio pager which can appropriately display the remaining amount of a battery and can effectively use the battery. I do.

[0015]

According to a first aspect of the present invention, there is provided a battery remaining amount detecting device which measures a voltage drop when a load is imposed on a battery.
The battery remaining amount is displayed and output according to the amount of the voltage drop, so that the battery remaining amount can be properly displayed.

According to a second aspect of the present invention, in order to solve the above-mentioned problems of the prior art, a battery remaining amount detecting device measures a voltage drop when a load is imposed on a battery and determines the amount of the voltage drop. When the value is larger than the value, the process using the large current is not performed, and the battery with a small remaining amount can be effectively used to the end.

According to a third aspect of the present invention, there is provided a radio call receiver for solving the problems of the prior art.
Alternatively, a battery remaining amount detecting device according to the second aspect is provided, so that the remaining battery amount of the radio call receiver can be accurately known, and a battery with a small remaining amount can be used effectively to the end.

[0018]

Embodiments of the present invention will be described with reference to the drawings. The battery remaining amount detecting device (the present device) according to the embodiment of the present invention has a voltage magnitude (differential coefficient) that drops in a very short time when a constant load is applied to the battery.
However, regardless of the discharge characteristics of the battery, the battery remaining amount is displayed according to the differential coefficient using the fact that it is related to the battery remaining amount. Can be displayed properly.

Further, when the differential coefficient obtained when a certain load is applied to the battery becomes larger than a specific value, the present apparatus uses a process using a large current (for example, turning on a backlight, vibrator operation, sounding, etc.). , Etc.), and a battery with a small remaining amount can be used effectively to the end.

Further, the radio paging receiver according to the embodiment of the present invention includes the above-mentioned device,
The battery remaining amount is properly displayed, and the battery with the small remaining amount can be used effectively to the end.

As shown in FIG. 1, the present apparatus comprises a battery 4 and
A display unit 5, an MPU 11, an A / D converter 13,
It comprises a switching circuit 14 and a load 15. FIG. 1 is a configuration block diagram of a battery remaining power detection device according to an embodiment of the present invention.

Hereinafter, each part will be described in detail. MPU1
1 outputs a signal for periodically turning on the switching circuit 14 (hereinafter, referred to as a “switching signal”).
The digital signal input from the / D converter 13 is measured for a drop per minute time, and the remaining amount of the battery is displayed on the display unit 16 according to the drop amount. Details of the processing of the MPU 11 will be described later.

The A / D converter 13 converts a voltage signal of the battery 4 into a digital signal and outputs the digital signal to the MPU 11. The switching circuit 14 transmits the output of the battery 4 to the load 15 while the switching signal is being input from the MPU 11, and is specifically realized by using a transistor. The load 15 is a resistance element and applies a constant load to the battery 4.

Here, the operation of the MPU 11 will be described with reference to FIG. FIG. 2 is a flowchart illustrating the processing performed by the MPU 11. It is assumed that the MPU 11 does not output a switching signal at first, and thus no load is applied to the battery 4.

The MPU 11 records a digital signal (Vdd1) corresponding to the voltage signal of the battery 4 when no load is applied via the A / D converter 13 (S1). Then, the MPU 11 outputs a switching signal (S
2) A load is applied to the battery 4, and after a certain period of time has passed (S3), the switching signal is not output (S4).

Then, the MPU 11 records a digital signal (Vdd2) corresponding to the voltage signal of the battery 4 input from the A / D converter 13 (S5), and calculates a differential coefficient ΔX from the following [Equation 1]. (S6).

[0027]

(Equation 1)

Here, Δt is the time waited in process S3.

After calculating the differential coefficient, the MPU 11 checks whether or not the differential coefficient ΔX is smaller than a predetermined first threshold value (S7).
For example, as shown in FIG. 5A, a display indicating that the remaining battery power is sufficient is performed (S8).
Processing ends.

The first to fourth threshold values represent the degree of battery consumption per unit time. The first threshold value corresponds to the case where the degree of battery consumption is the smallest. ,
This corresponds to the case where the degree of wear increases in the order of the third and fourth threshold values.

In step S7, if the difference is not small (if No), the derivative .DELTA.X is set to a predetermined second value.
It is checked whether or not the threshold value is smaller than the threshold value (S9).
Is displayed (S10), and the process ends.

Further, in step S9, if not small (No), the MPU 11 checks whether the differential coefficient ΔX is smaller than a predetermined third threshold value (S11). If it is small (if Yes), for example, a display as shown in FIG.
2) The process ends.

Further, in step S11, if not small (No), the MPU 11 checks whether or not the differential coefficient ΔX is smaller than a predetermined fourth threshold value (S13). If it is small (if Yes), for example, a display as shown in FIG.
At the same time, the process using the large current is not performed (S15).

In order to prevent the process using the large current from being performed, a flag indicating whether or not the process using the large current is prohibited is prepared, and before the MPU 11 performs the process using the large current. Then, the processing can be started after checking the state of the flag. The flag may be reset when the battery is replaced.

Further, in step S13, if it is not small (No in step S13), the MPU 11 immediately outputs a display to the effect that the battery should be replaced on the display unit 5 (S1).
6). The MPU 11 performs the process S16,
It is conceivable to perform processing such as sounding an alarm sound.

According to the present apparatus, the remaining battery level is detected not by the battery voltage but by the amount of voltage drop (differential coefficient) when a constant load is applied to the battery. Instead, the remaining battery level can be accurately displayed.

Further, according to the present apparatus, when the differential coefficient is extremely large, the process using a large current is prohibited, so that even a battery with a small remaining amount can be effectively used to the end. There is.

Further, according to the radio pager (pager) provided with the present apparatus, by having the remaining battery level detecting function of the present apparatus, it is possible to properly know the time to replace the battery and to erase important data. Has the effect of disappearing.

Further, even in a pager equipped with a used battery, there is an effect that a process requiring a large current is prohibited by applying a constant load, and a receivable state can be lengthened.

Further, it is conceivable that the present apparatus is used for a portable terminal such as a portable telephone, a PHS, and a personal computer other than a pager, so that it is possible to properly know the battery replacement time.
The effect that the battery whose remaining amount is low can be used effectively can be obtained.

[0041]

According to the first aspect of the present invention, the remaining battery level is measured by a voltage drop when a load is imposed on the battery.
Since the battery remaining amount detecting device is configured to display and output the battery remaining amount, there is an effect that the battery remaining amount can be appropriately displayed regardless of the voltage characteristic during discharging.

According to the second aspect of the present invention, a voltage drop when a load is applied to the battery is measured, and when the amount of the voltage drop becomes larger than a specific value, a process using a large current is not performed. The battery remaining amount detecting device has the effect that a battery having a small remaining amount can be used effectively to the end.

According to the third aspect of the present invention, since the radio paging receiver is provided with the battery level detection device according to the first or second aspect, the battery level of the radio pager is properly known. Thus, there is an effect that a battery with a small remaining amount can be effectively used to the end.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of a battery remaining power detection device according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating a process performed by an MPU 11;

FIG. 3 is an explanatory diagram showing voltage characteristics of a battery.

FIG. 4 is a configuration block diagram of a conventional battery remaining amount detection device.

FIG. 5 is an explanatory diagram showing a display example of a remaining battery level.

[Explanation of symbols]

1 A / D converter, 2 MPU, 3 ROM
4 ... battery, 5 ... display, 11 ... MPU, 13 ...
A / D converter, 14 ... switching circuit, 15
…load

Claims (3)

[Claims] 1. A battery remaining amount detecting device which measures a voltage drop when a load is imposed on a battery and displays and outputs a battery remaining amount in accordance with the amount of the voltage drop. 2. The battery according to claim 1, wherein a voltage drop when a load is imposed on the battery is measured, and when the amount of the voltage drop exceeds a specific value, a process using a large current is not performed. Remaining amount detection device. 3. A radio paging receiver comprising the battery level detection device according to claim 1.