| 摘要 |
<p>PROBLEM TO BE SOLVED: To simplify an electric structure, to reduce the cost and size, and to increase the reliability on a danger report with high time responsiveness. SOLUTION: The vibration signal Svx by a vibration detecting element 11x is applied to the field effect transistor FET1x of an impedance converting means 13x. The source and drain output voltages Vs, Vd of the FET1x are fed to a full-wave rectifying means 200x, and the absolute value signal Sax is inverted and amplified by an amplifying means 300x. Only the pinch-off voltage Vp of FET2x is level-shifted by the level shifting means 41x of an analog square arithmetic means 400x and applied to the field effect transistor FET2x of a source ground type amplifying square means 42x. The vibration information signals Six, Siy, Siz outputted from X, Y, Z axial direction vibration information acquiring devices 1000x, 1000y, 1000z are added by an addition arithmetic means 2000, and the synthetic acceleration information signal Sc is determined by an earthquake motion level determining means 3000.</p> |
