Both the rotors of the collector and those of the super exciter are composed of a series of thin copper plates held side by side very close to each other by a copper sheet to which they are soldered at one end.

Each rotor is hinged to the frame of the machine on the side of the plate and rubs on the centre of the moving part (collector or super exciter); while on the free end there is a hinged, copper pressure bar that acts on the rotor by means of a bearing of sufficiently soft and flexible insulated material.

The contact between the rotors and the collector takes place on the plane, passing through the rotation axis, perpendicular to the induction line: the plane on which, with every turn of the armature, the induction flow concatenated with that of the sixteen coils that pass through it on one side is maximum becomes minimum when that coil passes on the diametrally opposite side, it decreases when it passes from the first to the second position and increases when it returns. Therefore the f.e.m. induced in each coil is nullified when it crosses that plane and then changes signs (inversion plane), maintaining the same sign when it is on one side and the opposite sign when it is on the other side. ...continues