Abstract: This invention is a small light weight underwater transducer that operates at low frequencies. The foregoing is accomplished by embedding piezoelectric material in the wall of an oval shell between the shell's nodal points. When an alternating voltage is applied to the piezoelectric material, the piezoelectric material expands and contracts causing large circumferential strains in the shell of the transducer. The aforementioned strains cause the shell to vibrate and energy to be radiated into the water. This invention may also be used as a receiving type of transducer.

Abstract: This invention is a device that permits a flextensional transducer to function after the flextensional transducer experiences a pressure equal to or greater than the pressure found at the survival depth of prior art flextensional transducers. The foregoing is achieved by not bonding at least one end of the transducer's piezoelectric stack to the transducer's shell and having the other end or ends of the piezoelectric stack held in the vicinity of the transducer's shell by a pair of guide rails, etc. This permits the transducer's shell to move away from at least one end of the piezoelectric stack at pressures equal to or greater than the pressure at which the stack would experience tensile stresses in a conventional flextensional design. Thus, the piezoelectric stack will not fracture since it receives no tensile stress.