| 摘要 |
PURPOSE:To simplify constitution and achieve the improvement in electrostatic shield effect by polyarizing a piezolectric ceramic cylinder with the outer electrode as a neutral point, one of the inner electrodes + and other -. CONSTITUTION:Top cover 31 and bottom cover 32 composed of metal material or the like are bonded to the top and bottom ends of a polarized piezoelectric ceramic cylinder 1', the outer electrode 12 of the cylinder 1' being electrically connected to the top and buttom covers 31, 32 and connected to the shield braiding 36 of a cable to ground. On the other hand, + electrode 13 and - electrode 14 are connected via + terminal 40 and - terminal 41 to + cable core 34 and - cable core 35 to form a balance type circuit to obtain signal outputs. In addition, rubber boot 33 and cable sheath 39 are bonded and castor oil 42 is filled to the inner side of the rubber boot 33, i.e., the inside of the receiver. Air bag or sponge or the like is affixed to the surfaces of the electrodes 13, 14 to obviate exertion of pressure from the inside of the cylinder 1'. Thereby, the underwater receiver of high sensitivity and low noise may be obtained. |
