Method and apparatus for detecting defects in piezoelectric actuators

摘要: Roughly described, piezoelectric actuators are tested as part of an assembly using a three-stage process. In the first stage, substantially steady state electromechanical potential is induced into member assembly. Typically this can be accomplished by applying DC voltage across crystal for long enough period time it to achieve mechanical distortion. second actuator discharged rapidly but incompletely. The third stage begins with abrupt termination rapid-discharge thereby causing crystal, and produced it, oscillate decay freely. continues slowly in oscillations continue magnitude well, providing relatively complex signal from which features extracted compared those known-good devices.