Abstract: An automatic control system for a series circuit, in particular for airport signaling lights, physically separated from the work circuit feeding the lights and galvanically separated from the latter, includes a computer; several Main Stations each containing several Main Modules, each controlling several Remote Modules which check and act on a single airport light, each of said Main and Remote Modules having firmware boards; a full duplex transmission network linking the computer with the Main Stations; each Remote Module has externally two pairs of electric terminals of which one pair is connected to the secondary of an insulating transformer making part of the work circuit and the other pair is connected to a light or a group of lights being controlled, the two pairs of electric terminals being connected to each other by electrical leads, wherein connected in series to one of the electrical leads is a coil which is magnetically coupled to a Hall sensor of the Remote Module; and further including an electron