Abstract: Various embodiments of the teachings herein include a method for detecting a current of a first conductor of a circuit at least partly mounted on a printed circuit board. An example includes: arranging two bodies around the conductor so loops are operated in the plane concentrically around the first current conductor; the bodies are conductively connected by a second current conductor forming a U profile perpendicular to the plane; operating the first body with a first input of a transimpedance amplifier formed by an operational amplifier and the second body with a second input of the transimpedance amplifier in connection so the transimpedance amplifier brings about a short circuit; wherein a short-circuit current flows from the transimpedance amplifier as input variable of the transimpedance amplifier through the first body, the second body, and the functionally connected second current conductor, and generates a voltage at an output of the transimpedance amplifier.