An ultrasonic generator configured to supply an electrical power configured for fragmenting calculi, the ultrasonic generator being assignable a sonotrode, an ultrasonic vibration excitor configured to excite a vibration of the at least one sonotrode, and a force generation apparatus configured to generate a force for moving a projectile for shock excitation of the sonotrode, with the ultrasonic vibration excitor being excitable at a vibration frequency by the ultrasonic generator by supplying an AC voltage, the ultrasonic generator comprising:
- a measuring apparatus with at least one measuring unit configured to measure a time profile of a voltage and/or current, and an open-loop and/or closed-loop control apparatus configured to adjust an electrical power suppliable by the ultrasonic generator to the ultrasonic vibration excitor, with the measuring apparatus comprising at least one resistor arranged in parallel with the at least one measuring unit and a capacitor arranged in parallel with the measuring unit, wherein the measuring apparatus comprises, in parallel with the at least one measuring unit, at least one suppressor diode configured to suppress overvoltage.