| 摘要 |
PURPOSE:To make a user informed of the cause of a power source voltage drop by performing annunciating operation different from normal selective calling annunciation when power consumption decreases and a source voltage drops down to a lower voltage. CONSTITUTION:A low-voltage detection part 11 generates a stable reference voltage for a battery 2 and outputs a low-voltage detection signal to a ringing generation part 8 when the battery voltage drops below the reference voltage, i.e. enters a state LV. The generation part 8 once receiving the detection signal informs the user of the low-voltage state by a signal different from a call signal. In this case, if the source voltage enters the state LV owing to a large current, the volume and frequency of a ring-back tone or ringing for the start of receiver operation right after a switch 1 is turned on and the way of disconnection, etc., are made different from normal ones to let the user know the state LV. If the source voltage is in the low-voltage state even when a large current is not consumed, complete deterioration of the power source is reported by different ringing. |
