Abstract text

In a piezoelectric actuator control device for controlling operation of one or more piezoelectric actuators, when receiving a drive signal of a low level, a discharging switch is repeatedly turned on and off in order to discharge electric charge accumulated in the piezoelectric actuator. That is, the discharging switch is kept ON until a discharging current from a piezoelectric actuator reaches a peak threshold value Ip. When the discharging current reaches the peak threshold value Ip, the discharging switch is turned OFF and kept OFF until a discharging current from a piezoelectric actuator reaches a peak threshold value Ip. The device has a threshold value setting circuit for increasing the peak threshold value according to a discharging period of time.