| 摘要 |
PROBLEM TO BE SOLVED: To suppress consumption of backup battery by conducting intermittent transmission control so as to send selectively radio calling data in a transmission signal format when a commercial AC power supply is failed. SOLUTION: An AC voltage from a commercial AC power supply 1 is rectified into a DC voltage B by a rectifier circuit 2 to charge a battery 4 and fed to the radio calling transmitter 5 as a DC power supply voltage Vo . A DC/DC voltage converter 6 regulates a DC voltage V2 to be a prescribed constant voltage. A transmission section 7 sends a transmission signal from a signal input terminal 8 by a prescribed system and outputs the modulated signal to an antenna 12 from a transmission output terminal 11. When the commercial AC power supply 1 is failed, an output voltage V' of the battery 4 is fed to a radio calling transmitter 5 as a DC power supply Vo . In this case, a control section 9 forms a transmission signal S with a synchronizing signal, a preamble data signal section and a calling signal section and the operation of the transmission section 7 is inhibited for pseudo data. |
