| 摘要 |
PURPOSE:To effectively save depleted power of a battery by interrupting power supply automatically when communication between a slave set and a master set or a public base station has a difficulty and the state lasts for some time. CONSTITUTION:Whether or not notice channel synchronization is taken is decided in the digital cordless telephone set by tuning in to a frequency whose input level is maximum based on electric field strength data. When the synchronization is not taken, timers A, B, whose expiration is set to a prescribed time are operated. The expiration time of the timer B is set longer than that of the timer A. Whether or not the timer B is up is confirmed succeedingly and when the timer B is up, a power switch 8 is driven and supply of power from a power supply section 9 to each section is interrupted. When the timer B is up whether or not the timer A is up is confirmed and when the timer A is up, a warning tone 7 is raised to be sent. |
