| 摘要 |
PROBLEM TO BE SOLVED: To continuously receive calling by feeding the power from a secondary battery, when the output voltage of a primary battery is lowered or when a battery is replaced. SOLUTION: When the power is fed to a radio section 105 from a removable primary battery 101 via a power supply switching section 103, a secondary battery 102 is charged, via a charge control section 107, with an output of a step-up circuit 106 for stepping up an output of the primary battery 101. When the primary battery 101 is not loaded or a detection circuit 104 has detected that an output voltage of the primary battery 101 has become lower than a specified value, a control section 108 instructs the power supply switching section 103 to feed the power from the secondary battery 102 and also instructs an information control section 110 to inform of user that power is being fed from the secondary battery 102 with an notification method using as small a current as possible in the informing notification part 111. |
