JP3190112B2 - Battery level display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery level display device for displaying a battery level in electronic equipment using a battery.

[0002]

2. Description of the Related Art In an electronic device using a battery as a power source, it is necessary to know when to replace the battery or to know how much the electronic device can be operated with a current battery. This is convenient and important in preventing accidents in which input data and calculated data are lost due to battery exhaustion during use.

[0003] Therefore, some electronic devices are equipped with a battery level display device.

[0004] Generally, when the battery is consumed and the remaining amount is reduced, the discharge voltage is reduced, and finally the voltage becomes unusable. The conventional battery remaining amount display device detects and displays the discharge voltage and informs a person who handles the electronic device of the remaining battery amount.

[0005]

Some of the batteries are dry batteries,
Also, there is a rechargeable battery represented by a nickel-cadmium battery, and in recent years, electronic equipment has been improved in convenience by using either a dry battery or a rechargeable battery.

However, a rechargeable battery such as a nickel-cadmium battery and a dry battery have different discharge characteristics as shown in FIGS. That is, in the nickel-cadmium battery, the voltage drop is small in a use state, and drops sharply in a consumed state. Further, the voltage drop in the dry battery gradually decreases in proportion to the battery usage.

Therefore, the remaining capacity of the battery is determined based on the battery characteristics of the nickel-cadmium battery.
If the remaining amount is set to 0, the battery may still be usable. Conversely, the remaining capacity of the battery is determined based on the battery characteristics of the dry battery.
Although the display is still usable when using a cadmium battery, there is a problem that the display is actually exhausted and unusable.

The present invention has been made in view of the above circumstances, and has as its object to provide a battery remaining amount display device which always displays an appropriate remaining amount of a battery regardless of whether a used battery is a rechargeable battery or a dry battery.

[0009]

According to the present invention, there is provided a discriminating circuit for judging a type of a battery, and a display capable of displaying a display content of a remaining amount corresponding to the type of the battery. Battery to select and display the remaining battery content
In the remaining amount display device, the determination circuit includes a discharge circuit and a discharge circuit.
Sample the voltage in the charged state and the non-discharged state
A sampling and holding circuit that outputs a
It has a comparative reference value that is set in the discharge state and the non-discharge state.
Difference value of the sampling voltage signal and the comparison reference value
Are compared to determine the type of battery .

[0010]

[Function] Dry batteries and rechargeable batteries have different discharge characteristics and cannot display the remaining battery level uniformly. The type of battery is determined by a determination circuit, and the remaining level display that matches the type of battery based on the determination result. Let

[0011]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a battery in use. The battery 1 is connected to a determination circuit 2 for determining whether the battery is a nickel-cadmium battery or a dry battery.

A discharging circuit 4 having a switching element 3 is connected to the battery 1, and a sample and hold circuit 5 is connected to the battery 1, and the sample and hold circuit 5 turns on the switching element 3 of the discharging circuit 4. The voltage at the time of / OFF is sampled and held, and a sampling voltage signal is output. A signal from the sample and hold circuit 5 is converted into a digital signal by an A / D converter 6 and input to a microcomputer 7. The microcomputer 7 issues an ON / OFF operation command for the switching element 3 to the discharge circuit 4 and issues a signal capture command to the sample and hold circuit 5.

A comparison reference value 9 is set and input to the microcomputer 7 and compares the sampling signals at the time of ON / OFF. Based on the comparison between the comparison result value and the comparison reference value 9, the type of battery is determined. The display 8 is driven based on the determination result. The display 8 selects a battery type name and a scale for displaying the remaining amount according to a signal from the microcomputer 7 and displays the selected scale.

Next, the operation will be described with reference to FIG.

The determination circuit 2 determines whether the battery is a nickel-cadmium battery or a dry battery, and, after the determination, displays the remaining amount according to the type of the battery.

The battery discriminating operation by the discriminating circuit 2 is as follows.
The determination may be automatically performed by loading a battery, or a remaining amount detection button may be provided, and the detection circuit may be pressed to activate the determination circuit 2.

When the discriminating circuit 2 starts operating, first, the microcomputer 7 issues a signal fetch command to the sample and hold circuit 5 in a state where the switching element 3 is OFF, that is, in a non-discharged state, and the voltage of the battery 1 is sampled. In both cases, the sampling voltage signal is held by the sample and hold circuit 5, and further converted into a digital signal by the A / D converter 6 and input to the microcomputer 7.
The microcomputer 7 stores a signal during non-discharge.

Next, a command is issued from the microcomputer 7 to the switching element 3 and the sample and hold circuit 5, and the switching element 3 is turned on and the battery 1 is turned on.
Is discharged, the voltage at this time is sampled,
The sampling voltage signal is held by the sample and hold circuit 5, converted into a digital signal by the A / D converter 6, input to the microcomputer 7, and further stored in the microcomputer 7.

In the microcomputer 7, a difference value obtained by subtracting a sampling voltage signal in a discharging state from a sampling voltage signal in a non-discharging state is compared with the comparison reference value 9. When the difference value is smaller than the comparison reference value 9 when the difference value is smaller than the comparison reference value 9, it is determined that the battery is a nickel-cadmium battery. When the difference value is larger than the comparison reference value 9, it is determined that the battery is a dry battery. . The result of this determination is output to the display 8, and the display 8 displays a display corresponding to the type of the loaded battery. For example, if the loaded battery is a nickel-cadmium battery, the contents shown in FIG. It is selected and displayed, and if it is a dry battery, FIG. 4 is displayed.

Thus, the person who handles the electronic device can properly know the remaining amount of the battery regardless of the type of the battery.

[0022]

As described above, according to the present invention, the dry battery and the rechargeable battery have different discharge characteristics and cannot display the remaining battery level uniformly. However, the type of the battery is determined by the determination circuit, and the determination result is obtained. Is displayed based on the battery type, so that the electronic device operator can know accurate information on the remaining battery level.

[Brief description of the drawings]

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

FIG. 2 is a flowchart of the embodiment.

FIG. 3 is an explanatory diagram showing an example of battery display contents.

FIG. 4 is an explanatory diagram showing another example of battery display content.

FIG. 5 is a diagram showing discharge characteristics of a nickel-cadmium battery.

FIG. 6 is a diagram showing discharge characteristics of a dry battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery 2 Discrimination circuit 3 Switching element 4 Discharge circuit 5 Sample hold circuit 6 A / D converter 7 Microcomputer 8 Display 9 Comparison reference value

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01R 31/36

Claims (1)

(57) [Claims] 1. A discriminating circuit for judging a type of a battery and a display capable of displaying a remaining amount display content corresponding to the type of the battery, and the remaining amount display content is selected on the display according to a judgment result of the discriminating circuit. Battery level display device
The discrimination circuit includes a discharge circuit and a discharge state and a non-discharge state.
Voltage and outputs a sampling voltage signal.
The sampling hold circuit and the set comparison reference value
Provided, sampling voltage in discharge state and non-discharge state
By comparing the difference value of the signal with the comparison reference value,
A battery level display device for determining a type .