A current sensor can detect and measure direct currents (DC currents). Current sensors are "all-current sensitive". This is the main difference to the current transformer, which can only map alternating currents (AC currents). Two measuring principles / effects are typically used here. The Hall effect: Named after Edwin Hall, the discoverer of this phenomenon, the occurrence of an electrical voltage in a current-carrying conductor that is in a stationary (unchanged) magnetic field. And the measurement with magnetic probe (flux gate). This consists of a soft magnetic core and an excitation coil that is used to detect the magnetic flux density. The current sensors are available in the versions open-loop sensor (direct imaging sensor) and closed-loop sensor (compensation sensor).