| 摘要 |
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. |
