| 摘要 |
PROBLEM TO BE SOLVED: To resume power supply by preparatory power and restart a portable telephone, when power supply to the portable telephone is stopped, due to the drop of the voltage of its battery. SOLUTION: A portable telephone 1 is formed, having a battery 2, a power supply control unit 3, a battery voltage comparison control unit 4, a communication part 5, and an operation part 6. The comparing part 4 performs control so as to stop power supply to the communication part 5, if a detected battery voltage becomes equal to or lower than a specified preliminary voltage. After that, power supply is restarted by the operation of the operation part 6, and operation is continued by preliminary power. All the power supply is stopped, when the battery voltage is lowered further and becomes equal to or lower than a stoppage voltage. |
