The Metropolitana di Milano is operated via one line on the side for power input and a separate rail in the centre of the track for the energetic recovery system. It also uses direct current at a running voltage of 750 Volt.
From 2012 to 2013, APS electronic AG was commissioned to deliver 19 brake excitation systems and battery chargers. Input is 15000 VDC, output 1 0..94 VDC / 300 A and output 2 72 DVC /120 A. The devices each weigh 320 kg. Click for more information on the technical specifications of the brake excitation systems and battery chargers used.