Vibrators

Piezo-Transducer-Vibrators are miniature devices that emit both audio and silent signals and are currently targeted for use as an integral part of wristwatch technology. Utilizing nonlinear finite element analysis is essential for obtaining a greater understanding of the system response under varying conditions. Dyna3D nonlinear finite element code is applied in this analysis with the focus on the mechanical aspects of the vibrator. Four impact variables, the velocity, the plate gap, the weight and the velocity angle are studied to determine the effects on the system response. Each impact variable is assigned three separate values, creating twelve programs for analysis. For each program, responses to impact conditions are studied demonstrating the deformed mode shapes, maximum principal stresses and maximum displacements using state database plots and time-history plots.

A state-of-the-art Piezo-Transducer-Vibrator suitable for a wristwatch has been developed based on a "Customer Comprehension" program: To look at the product from the customer point of view and try to satisfy those needs simultaneously using computer simulation leading to a reliable design in a shorter cycle time. This device is a miniature integrated compact form of both audio and silent alerts which uses less than 8 mA current; desirable to be used in equipments with very small power sources. A new ergonomic study was conducted in comprehending the minimum acceptable shake and frequency on human wrist. The complete Piezo-bender structure, its driving format, and its vibration has been modeled accurately to obtain an optimum geometry design for the best possible shake, satisfying all constraints.