MALFUNCTION DETECTOR OF PIEZOELECTRIC ACTUATOR

摘要

PROBLEM TO BE SOLVED: To provide a malfunction detector of a piezoelectric actuator which enables detecting more precisely malfunctions as a partial break or short- circuiting of the piezoelectric actuator. SOLUTION: This malfunction detector of a piezoelectric actuator is provided with a high voltage generating circuit 2 for generating high voltage to apply to a piezoelectric actuator 1 which comprises layered elastic piezoelectric materials 11 according to applying voltage, and a switching circuit 3 for applying to piezoelectric actuator 1 a high voltage which is generated in a high voltage generating circuit 2 during turning on of a switching element to charge and for discharging stored charge to piezoelectric actuator 1 during turning on of the switching element to discharge. Abnormality status is detected in detail by detecting with an malfunction detecting circuit 5 piezoelectric actuator voltage at a definite period of time after a control circuit 4 outputs a charging/ discharging voltage into switching circuit 3 and comparing the voltage with the normal value of the piezoelectric actuator voltage at the moment.