Abstract: The invention discloses a detection- and recording system for high intensity electric currents such as lighting currents in a lighting conductor in a wind turbine. The system comprises a detector (6) containing a power supply (7), a measuring circuit (8), and a converter means (9) and furthermore a recording means (11) non-galvanically coupled to said converter means (9) and a measuring coil (5) to be inductively coupled to an electric conductor (2) carrying the high intensity electric current. The power supply (7) receives its electrical energy directly from the lighting current via the power coil (4) which makes the system non-sensitive to mains supply drop-outs.