Circuit device for actuating piezo-electric actuator for injection valve of internal combustion engine in motor vehicle, has ohmic resistor whose value is chosen based on characteristic of mechanical and electrical properties of actuator

摘要

The circuit device (10) has a damping unit (30) for damping of a piezo-electric actuator (12). The damping unit is equipped with a semiconductor switch (32) and an ohmic resistor (34). The value of the ohmic resistor is chosen based on the characteristic of mechanical and electrical properties of the piezo-electric actuator. The value of the ohmic resistor is calculated with specific formula relating the capacitance and natural oscillation frequency of piezo-electric actuator, and is set larger than 0.5-5 ohms. An independent claim is included for method for operating circuit device for actuating piezo-electric actuator.