Driving apparatus for piezo-actuator having abnormality detecting function

摘要

In a driving apparatus (1) for piezo-stacks (INJ1 - INJ4), a controller (4) repeats switching operation for turning switching elements (T52 and T53) on/off to thereby attain a determined piezo-actuator voltage. An abnormality detecting circuit (41) determines abnormality of the piezo-stacks (INJ1 - INJ4) by comparing the number of times of charging (Nc) and the number of times of discharging (Nd), or charging/discharging time periods (Tonc, Tond) at this occasion with those at normal time. <IMAGE>