Monitoring system for electrically actuated control element

摘要

A piezo-electric control element with a monitoring system is formed of lamellae of piezo-electric material whose longitudinal direction extends in an actuation direction of the control element. The lamellae are interconnected to form at least one lamella packet and electrodes are provided for applying electric actuation voltage at opposite principal faces of the lamella. At lest one lamella of the packet has on one principal face a measuring electrode which extends over a portion of the lamella and which is opposite a cooperating electrode on an opposite principal face of the lamella. The measuring electrode has an electric terminal separately provided for measurement of displacement and/or speed, or actuating force.