| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an acceleration seismograph device which outputs analog detection signals according to the magnitude of an earthquake. SOLUTION: This acceleration seismograph device is provided with a bobbin 22 around which a coil 29 is wound, a magnetic pole 23 screwed into the bobbin 22 inside the coil 29 so as to be movable up and down, and a permanent magnet 26 which is movable over the magnetic pole of the bobbin 22. At the time of an earthquake, by the shifts of the relative locations of the permanent magnet 26 and the bobbin 22, an induced current and voltage which occur in the coil 29 are outputted as signals of the magnitude of vibrations. As the induced current and voltage occur in the coil 29 according to the magnitude of the vibrations of an earthquake, etc., the magnitude of the vibrations can be detected by detecting the induced current and voltage. Further, the permanent magnet 26 is polarized, and a magnetic shielding plate 27 is installed on the top of the permanent magnet 26. By the installation of the shielding and weight plate on the permanent magnet 26, a magnet flux can be concentrated to the side of the magnetic pole. And by suitably setting the mass of the plate, the permanent magnet 26 which does not follow the up-and-down, side-to-side vibrations of the bobbin 22 consequent upon the earthquake is obtained.</p> |
