Abstract: A method and device for charging and/or discharging a capacitive element. A controllable switch is driven to interrupt the charging current when the charging current exceeds a predetermined charging-current threshold. The charging-current threshold is altered while the capacitive element is being charged to the predefined charging voltage. The controllable switch is driven again for coupling the charging current into the capacitive element if a predefined period of time after a previous activation of the controllable switch has elapsed, and/or in case the charging current drops below the predetermined charging-current threshold. A discharging process is carried out correspondingly.

Abstract: An electric circuit for triggering a piezoelectric element, in particular of a fuel injection system of a motor vehicle. Two transistors connected in series and triggerable using a clock pulse are provided, whose shared connecting point is coupled to the piezoelectric element and one of which is provided for discharging the piezoelectric element. In the event of an error, the transistor provided for discharging can be triggered using the clock pulse.

Abstract: An electric circuit for triggering a piezoelectric element, a fuel injection system of a motor vehicle in particular, is described. A first measuring shunt connected in series to the piezoelectric element is provided. Provided are two transistors connected in series whose shared connecting point is connected to the piezoelectric element. A second measuring shunt is also provided. The two transistors and the second measuring shunt are connected in series.

Abstract: In an internal combustion engine, fuel is injected directly into a combustion chamber by an injector that has a piezoactuator. An electrical charge conveyed to and/or removed from the piezoactuator is ascertained by a method that is calibrated at least once during an operating time span of the internal combustion engine. To allow the calibration to be carried out or performed as often as possible, the method for ascertaining the electrical charge transferred to and/or removed from the piezoactuator may be calibrated during at least one triggering off-time (dtK) of the piezoactuator while the internal combustion engine is operating.

Abstract: In an internal combustion engine, fuel is injected directly into a combustion chamber by an injector that has a piezoactuator. An electrical charge conveyed to and/or removed from the piezoactuator is ascertained by a method that is calibrated at least once during an operating time span of the internal combustion engine. To allow the calibration to be carried out or performed as often as possible, the method for ascertaining the electrical charge transferred to and/or removed from the piezoactuator may be calibrated during at least one triggering off-time (dtK) of the piezoactuator while the internal combustion engine is operating.