Patent ID: 7521838

Claim:
A device for operating a piezo actuator, comprising: a first energy control unit with a first pilot controller, which has a first transmission behavior and is operable to have a first setpoint energy value applied to it on the input side and to output a first pilot control signal on the output side, and a first regulator, which is embodied to output a first regulator signal as a function of the first setpoint energy value and a first actual energy value of the piezo actuator, wherein the first energy control unit is further operable to create a first control signal which represents a first current threshold value of a charge current for the piezo actuator, depending on the first pilot control signal and the first regulator signal, a second energy control unit with a second pilot controller, which has a second transmission behavior and which is operable to have a second setpoint energy value applied to it on the input side and to output a second pilot control signal on the output side, and a second regulator, which is operable to output a second regulator signal as a function of the second setpoint energy value and a second actual energy value of the piezo actuator, wherein the second energy control unit is further operable to create a second control signal which represents a second current threshold value of a charge current for the piezo actuator, depending on the second pilot control signal and the second regulator signal, a power output stage unit, which is operable to set a charge current for the piezo actuator depending on the respective predetermined control signal for a respective predetermined time, a scheduling unit, which is operable: to predetermine the first and second setpoint energy value, to determine the first and second actual energy values, to activate the first and second energy control units for creating the first and second control signals, to predetermine a charge pattern relating to the first to second setpoint energy values, to predetermine the first control signal and the first time to the power output stage unit for setting the first setpoint energy value, to predetermine the second control signal and the second time to the power output stage unit for setting the second setpoint energy value and to apply the signals to the power output stage unit for implementing the charge pattern.