| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a space alarm utilizing electromagnetic waves which is readily carried by a person and usable for avoiding forgetting some article or losing sight of other persons or animals. SOLUTION: An output contact for a receiver 4 is wired to an input contact of a receiving amplifier 5, an output contact of the receiving amplifier 5 is wired to an input contact of a logical NOT circuit 6, and an output contact of the logical NOT circuit 6 is wired to an input contact of an alarm unit 7.</p> |
