| 摘要 |
PROBLEM TO BE SOLVED: To securely detect the ground shorting of a current-carrying cable to a piezo stack in a piezo actuator driving circuit. SOLUTION: In a detection point 401A in which a line 222A from a ground side terminal 202A to which a current-carrying cable 32A to the piezo stack 11A is connected to ground is opened by a switch means 25A and which is conducted with a ground side terminal 202A when abnormality is detected, a comparator 32 reads the level of voltage obtained by dividing constant voltage by a pair of resistors 411 and 412 so as to judge whether the cable 32A is ground-shorted or not. Consequently, the difference of voltage with that at normal time can be made large even if it is half-shorted without affecting charging/discharging by making the resistance values of resistors 411 and 412 to be sufficiently large.
|
