Abstract: A device for feeding electricity into a Faraday cage comprises an electrical generator (8), a generator drive motor (3), and a linkage (12, 24) for mechanically coupling the generator and the motor. The device is characterized in that it includes linkages (2, 12, 24) for electrically isolating the motor and the generator from each other, together with an electromagnetic screening element (7, 15; 20) surrounding the generator and connected to the Faraday cage, the screening element including at least one waveguide passage (14, 25) through which the mechanical coupler extends.