Design and fabrication of Tonpilz type acoustic transducer using grain oriented Tb-Dy-Fe magnetostrictive material

A Tonpilz type transducer has been designed and fabricated using grain oriented Tb
_0.3
Dy
_0.7
Fe
_1.95
magnetostrictive rods as active elements. The design include provisions for DC biasing of the active elements with the help of an array of resin-bonded Nd-Fe-B ring magnets, AC drive coil and a pre-stressing mechanism. Resonance frequency of this transducer was found to be 1.6 kHz. A Transmitting Current Response (TCR) of 167 dB ref 1μPa/A at 1 m and a Transmitting Power Response (TPR) of 152 dB ref lμPa/W were achieved. The Source Level (SL) was determined to be 177 dB ref μPa at 1m.