Battery residual amount display circuit
First Claim
1. A battery residual amount display circuit which is incorporated in an apparatus having a plurality of operation modes and equipped with a battery as a power supply and which displays a residual amount of the battery, which comprises:
- voltage detecting means for detecting an output voltage of said battery;
mode detecting means for detecting an operation mode of said apparatus;
battery residual amount judging means for executing judgment of said residual amount by comparing said output voltage with predetermined threshold values when said mode detecting means detects a particular mode which is one of said plurality of operation modes, and for judging said residual amount by determining a voltage drop based on said output voltages, converting said voltage drop into a equivalent output voltage corresponding to said particular mode, and comparing said equivalent output voltage with said predetermined threshold values when said mode detecting means detects a mode other than said particular mode; and
display means for displaying said judgment result of the battery residual amount judging means.
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Accused Products
Abstract
At step S21, a residual amount judging section of abattery residual amount display circuit measures a battery voltage. If a mode transition is detected at step S22, the process returns to step S21 without executing the subsequent steps. If it is judged at step S23 that the operation mode is a reception-waiting mode, the process goes to step S24, where the battery amount judging section judges a battery residual amount by comparing the detected battery voltage with threshold values. If the operation mode is judged to be a transmission mode, the battery residual amount judging section determines a voltage drop during a transmission at step S25, and converts the voltage drop into a battery voltage of a reception waiting mode at step S26 by subtracting the voltage drop from a batter voltage obtained in a reception waiting mode immediately before the mode transition. At step S27, the battery residual amount judging section determines a battery residual amount by comparing the converted battery voltage with the threshold values.
10 Citations
9 Claims
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1. A battery residual amount display circuit which is incorporated in an apparatus having a plurality of operation modes and equipped with a battery as a power supply and which displays a residual amount of the battery, which comprises:
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voltage detecting means for detecting an output voltage of said battery; mode detecting means for detecting an operation mode of said apparatus; battery residual amount judging means for executing judgment of said residual amount by comparing said output voltage with predetermined threshold values when said mode detecting means detects a particular mode which is one of said plurality of operation modes, and for judging said residual amount by determining a voltage drop based on said output voltages, converting said voltage drop into a equivalent output voltage corresponding to said particular mode, and comparing said equivalent output voltage with said predetermined threshold values when said mode detecting means detects a mode other than said particular mode; and display means for displaying said judgment result of the battery residual amount judging means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification