Patent ID: 8096285

Claim:
A circuit arrangement for operating an injector arrangement for injecting fuel in an internal combustion engine of a motor vehicle, wherein the injector arrangement comprises one or more injectors each formed from an electrically actuatable actuator and a fuel valve designed to be activated by means of the actuator wherein the fuel valve comprises a valve body arranged movably relative to a valve seat, wherein the circuit arrangement is formed to optionally supply an actuation voltage to each of the injectors for actuating the actuator via a conductor arrangement, and wherein the circuit arrangement is designed to superimpose a measuring signal onto the actuation voltage, such that the actuation voltage and superimposed measuring signal are applied to the actuator, and such that a sensing signal is formed which is representative of the position of the valve body relative to the valve seat, wherein an evaluation of the sensing signal comprises determining, a runtime delay of sound waves generated by the actuator and reflected at a nozzle needle of the fuel valve.