STATE CONTROL SYSTEM OF RADIO TELEPHONE EQUIPMENT

摘要

PURPOSE:To attain the replacement of batteries of a radio telephone without discontinuing the call state by supplying the voltage to a memory through a backup power supply for a fixed period of time after removing the battery of the radio telephone connected to a wire circuit. CONSTITUTION:A memory backup power supply circuit 27 is provided to a radio telephone 2 which is controlled by a connection device connected to a wire telephone circuit. The circuit 27 contains a large-capacity capacitor 271 which is charged via a diode 270 and a battery 26. The telephone 2 stores the number of the communication channel to a memory incorporated to a control circuit 24 via the wire circuit during communication. When the battery 26 is removed during communication, the communication channel number is held by the circuit 27 for a fixed period. Thus the call state is continued for the communication channel corresponding to the number held at the memory after the battery 26 is loaded within a fixed period of time.