| 摘要 |
PURPOSE:To realize a radio broadcast device which detects occurrence of the earthquake and then generates the alarm signal automatically. CONSTITUTION:In case the earthquake takes place while the aural signal is broadcasted through microphone 7 and the P wave of the earthquake, i.e., the vertical wave is detected by vertical earthquake detector 9, both contacts 12 and 13 of automatic switch circuit 11 shift by the output to the lower side as shown in the diagram to give switching to the side of special modulation wave circuit 10. And radio transmitter S transmits the sine wave signal of 30Hz. On the other hand, the electric waves transmitted through transmission antenna 5 are received at receiver 15 via reception antenna 14, and only the sine wave signal of 30Hz is extracted out of the output through 30Hz-filter 16. With the detection signal, voltage relay 17 is turned on to operate elevator-nearest-floor stopping circuit 18 to make stop the elevator at the nearest floor. |
