| 摘要 |
PURPOSE:To provide a transducer by which bulk longitudinal elastic pulse groups permitting weighting with desired position relations are obtained by providing a thin film linear conductor of zigzag form of different pitches on an amorphous magnetostrictive thin plate and applying variable bias magnetic fields. CONSTITUTION:The amorphous magnetostrictive transducer is constituted on an amorphous magnetostrictive thin plate 1 by a zigzag form coil 6 which has a conductor width larger than the plate thickness of the thin plate 1 and is varied in folding back spacing and a solenoid coil 8 which is distribution wound in the advancing (longitudinal) direction of elastic waves for the purpose of application of bias magnetic fields. The magnetic field distribution of a certain instant by the high frequency current of this coil 6 becomes alternately positive and negative directions according to folding-back intervals in the longitudinal direction of the coil 6. D.c. bias magnetic fields having a certain distribution in the longitudinal direction are generated by the coil 8, and the distrifution of coupling coefficients having a relation with this is obtained. The respective crest values of the elastic stain wave group excited by the coil 6 are determined at a desired ratio by the distribution bias magnetic fields according to the distribution of the coupling coefficients and are obtained in the folding back positions of the coil 6. |
