JPH07131402A - Power supply monitoring device for mobile phones - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a mobile phone capable of talking for a long time by partially stopping the circuit operation depending on the power supply voltage. A circuit 3 for monitoring a power supply voltage, an indicator 8 for displaying a warning, a circuit 6 for generating a warning sound, a circuit for judging a power supply voltage drop, stopping the circuit operation, and issuing a warning command. 4 is provided. [Effect] It is possible to extend the call time by stopping the operation of the circuit that is not related to the call.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable telephone using a secondary battery as a power source, and more particularly to a portable telephone power source monitoring device for automatically stopping the operation of a circuit.

[0002]

2. Description of the Related Art In mobile phones, it is basically necessary to use a secondary battery as a power source. Therefore, for the purpose of battery protection or circuit protection, when the power supply voltage falls below a certain value, it automatically It is designed to turn off the power. This may be the case, for example, as shown in the magazine "Nikkei Trendy", published by Nikkei Home Publisher: July 1993 issue, page 48. In either case, the internal voltage relative to the final voltage of the secondary battery Since the minimum operation guarantee voltage of the circuit is set low, when the voltage of the secondary battery reaches the final voltage, all the operations are automatically stopped and the power is turned off.

[0003]

However, mobile phones tend to be smaller and lighter, and accordingly,
The secondary battery itself will also be smaller and lighter, and this final voltage will drop. As a result, the minimum guaranteed voltage partially exceeds the final voltage depending on the internal circuit. Therefore, in order to guarantee all the operations, the voltage setting for stopping the operations must match the circuit having the highest minimum guaranteed voltage.

If this circuit is a circuit that is not directly related to a call, the voltage is still available for call, but all the operations must be automatically stopped, which disables call.

The present invention has been made in view of the above points,
It is an object of the present invention to provide a mobile phone which can partially stop the circuit operation depending on the power supply voltage and can talk for a longer time.

[0006]

In order to achieve the above-mentioned object, the present invention partially suspends only the circuit whose power supply voltage has reached the minimum guaranteed voltage and puts other circuits into the operating state. It is configured.

Further, when the operation is partially stopped, the user is informed of this.

[0008]

When the mobile phone is in use, its battery voltage gradually drops. When this voltage falls below a certain value, the microprocessor built into the mobile phone judges this and cuts off the power supply to the circuit below the minimum guaranteed voltage, or sends an operation stop command signal to that circuit. broth,
Stop the circuit operation.

In this state, the microprocessor simultaneously uses a warning indicator such as an LCD or a warning sound generator such as a speaker to notify the user of the mobile phone that some of the functions have stopped.

When the battery voltage further drops and becomes lower than the minimum callable voltage or the cutoff voltage of the battery, the microprocessor judges this and stops all the operations and cuts off the power supply to the entire circuit. .

[0011]

The present invention will be described below with reference to the illustrated embodiments.

FIG. 1 is a block diagram showing only the part related to the present invention in the internal structure of a mobile phone.

In FIG. 1, reference numeral 1 is a secondary battery which is a power source,
Reference numeral 2 is a power supply circuit that supplies power to the entire circuit, 3 is a power supply voltage monitoring circuit, and 4 is a microprocessor that controls the entire system. 5 is a writable / readable memory,
It is mainly for storing abbreviated telephone numbers. Reference numeral 6 is a voice processing circuit, which is used for voice processing for transmitting / receiving and for generating a warning sound. Reference numeral 7 is a speaker, and 8 is a display (LCD). Reference numeral 9 is an input circuit (switch) for the user to input a telephone number or the like.

In this configuration, the microprocessor 4
Constantly compares the signal from the power supply monitoring circuit 3 with a specified value.

The certain specified value referred to here is three kinds (V
1, V2, V3), and each has a relationship of V1>V2> V3.

V1 is a determination value for notifying the user that the remaining battery level has decreased.

V2 is a value for determining write inhibition to the memory 5. Generally, a memory has a minimum writable voltage, and has a characteristic that erroneous data is recorded if writing is performed at a voltage lower than this voltage.

V3 is a determination value for stopping all circuits and turning off the power.

When the voltage of the secondary battery 1 drops and the signal from the power supply monitoring circuit 3 falls below V1, the microprocessor 4 commands the display 8 to display a caution message (mark) and prompts the user. , Informs that the remaining amount of the secondary battery 1 has decreased. In this state, the user inputs the abbreviated number through the input circuit 9, passes through the microprocessor 4, and the memory 5
Can be recorded in.

When the voltage of the secondary battery 1 further drops below V2, the microprocessor 4 prohibits writing to the memory 5, and at the same time instructs the voice processing circuit 6 to generate a warning sound, 8 is instructed to display a warning sentence to warn the user. In this state, even if the user tries to record the abbreviated number, it cannot be recorded, but the call is possible.

When the voltage of the secondary battery further drops and falls below V3, the microprocessor 4 commands the power supply circuit 2 to turn off the power, and stops all the operations of the mobile phone.

FIG. 2 shows a processing flowchart of the microprocessor 4 in FIG.

At step ST1, it is asked whether or not the power supply voltage is V1 or higher. If NO, the process proceeds to step ST2, where YE
If S, the process proceeds to step ST3 to stop the caution warning, and returns to step ST1.

At step ST2, it is asked whether or not the power supply voltage is V2 or higher. If NO, the process proceeds to step ST4 and YE.
If it is S, the process proceeds to step ST5 to display a caution for the remaining battery level and returns to ST1.

In step ST4, it is asked whether or not the power supply voltage is V3 or higher. If NO, the process proceeds to step ST6 and YE
If the result is S, the process proceeds to step ST7, the writing of the memory is prohibited, the warning display and the warning sound are generated in step ST8, and the process returns to step ST1.

At step ST6, the power is turned off to stop the operation.

[0027]

As described above, according to the present invention, the mobile phone can be used up to the final voltage of the battery by stopping the operation of only the circuits not directly related to the call, and the call time can be extended. You can

[Brief description of drawings]

FIG. 1 is a block diagram showing only the part related to the present invention in the internal structure of a mobile phone.

FIG. 2 shows a processing flowchart of a microprocessor 4 in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Secondary battery, 2 ... Power supply circuit, 3 ... Power supply monitoring circuit, 4 ... Microprocessor, 5 ... Memory, 6 ... Voice processing circuit, 7 ... Speaker, 8 ... Indicator, 9 ... Input circuit.

Claims (3)

[Claims] 1. A mobile phone using a secondary battery as a power source,
A power supply monitoring device for a mobile phone, which is characterized by automatically stopping a part of an internal circuit according to a power supply voltage. 2. A power supply monitoring device for a mobile phone according to claim 1, wherein a user is informed that a part of the circuit has stopped operating. 3. A power supply monitoring device for a mobile phone according to claim 1, wherein the callable time is extended by stopping the operation of only the circuit not directly related to the call according to the power supply voltage.