| 摘要 |
PURPOSE: To reduce power consumption by detecting a synchroning signal within regulated time, executing receiving operation, and when the synchroning signal is not detected, setting up a stand-by state. CONSTITUTION: At the time of detecting gas leakage, a detector transmits an alarm signal to a transmitter, the alarm signal is sent from the transmitter to a receiver 9 by a radio signal and a gas meter microcomputer 11 interrupts gas supply. Since voltage is intermittently impressed from a power supply 23 to a receiving part 13, a carrier is sensed by the receiving part 13, and if no carrier exists, the receiving part 13 is turned to a stand-by state. At the time of detecting a carrier, a CPU 17 detects a synchroning signal corresponding to a signal sent from the receiving part 13, and when no synchronizing signal is detected, whether the regulated time has elapsed or not is judged. When the regulated time has not elapsed, the receiving part 13 is returned to the stand-by state to sense a carrier again. When the regulated time has elapsed, the receiving part 13 executes the sense of a carrier as it is. |
