| 摘要 |
PURPOSE:To save the current consumption by actuating intermittently the power supply of a reception device while monitoring the incoming signal. CONSTITUTION:When a receiver 6 receives radio waves, an incoming detecting circuit 7 compares the individual identification signal received from a transmission device 1 with that set previously at an individual identification signal storage circuit 9. When the coincidence is obtained between both signals, the supply of power of a battery 11 is discontinued for a fixed period to the receiver 6 and the circuit 7 and then restarted by a main timer circuit 10. While an un-incoming state is decided if no coincidence is obtained between both identification signals, the power is continuously supplied by the circuit 10. Furthermore a secondary timer circuit 12 is actuated by the circuit 7 so that an alarm is produced from a sound generator 8 when an un-incoming state lasts for a fixed period during which the individual identification signals can be decided many times. As a result, the power consumption of the battery 11 is reduced. |
