Force restoration transducer

Force Restoration Transducer A device that uses electronic feedback to adjust the current in an electromagnet until it balances the force put against it by a mass, permitting a highly accurate determination of weight. 

Fig. 25.16 (a) Phase of the transmitted wave of fundamental frequency recorded at the receiving transducer, and (b) restoring force Fif derived from the transmission measurement data at an excitation peak power of... 

These present and future applications of piezoelectric devices all hinge upon their ability to transduce physical strains occurring in a solid to electrical potentials and vice versa. Strains are relative displacements of particles within a solid and cause the generation of restoring stress forces. Strains will also result in the establishment of electrical fields within the solid if the material is piezoelectric. 

The element common to the function of all piezoelectric transducers is particle displacement within a solid. Relative particle displacements cause the generation of restoring stress forces and for piezoelectric materials cause the generation of electrical fields as well. Displacement is defined as the vector indicating the difference between equilibrium and perturbed positions of a solid particle. However, this vector is not invariant to translational motion so that strain is used to represent relative displacement. Strain and displacement are related by the equation ... 

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