US Patent 7812503 Piezoelectric actuator drive device

A fuel injection control apparatus drives piezoelectric actuators for opening and closing injectors of respective cylinders based on energy stored in a capacitor of a DC/DC converter. A current detecting resistor for controlling a boost switch to charge the capacitor is disposed at a position at which current flowing through the capacitor is not detected. Further, current detecting resistors for controlling the piezoelectric actuators are disposed at positions at which charging current from a diode to the capacitor is not detected. Thus, the charging of the capacitor can be performed even during the control for charging/discharging the piezoelectric actuator.