| 摘要 |
<p>PURPOSE:To send surrounding sound without being noticed by a burglar or the like by adopting the constitution in such a way that an operation switch and a control section activating a talking device and a transmitter and stopping the receiver through the application of power by the operation of the said switch are provided. CONSTITUTION:A control section 1 consists of a power control circuit 11, a CPU 12, and switches 13,14. In closing an operation switch 12 on emergency, the power switch 6 is closed automatically, the receiver of a radio section 9 is operated, the CPU 12 opens the switch 14 to throw the switch 8 to select the output signal of the amplifier 7 and to close the transmission switch 5. As a result, the transmitter of the radio section 9 is acted and the switch 13 is closed. In this case, since the output signal of the transmitter 3 is amplified by the amplifier 7 and inputted to the transmitter at a level higher than the normal level, the surrounding sound is sent to an opposite station with sufficient sound volume. Since the operation of the receiver 4 is stopped by opening the switch 14, no noise is given from the receiver 4 and the performance of the transmission is not noticed of the burglar or the like.</p> |
