In order for tension and current to persist, the rotation of the armature must be in the direction in which the generated current, on passing through the electromagnet of the inductor, tends to increase the residual magnetization in its iron core.

When the resistance of the outer circuit is high, and in all cases in which one wishes to increase the magnetazation of the inductor, it is possible to insert a device which Pacinotti called a super exciter. It is composed of a cylinder (diameter 3.6 cm, height 3.5 cm) attached to and coaxial with the drive shaft, about three quarters covered with a conducting sheet and the rest with an insulator.Two copper rotors rub on it from two diametrally opposed sides; since they are connected to the terminals of the machine, they exclude and reconnect the load at every quarter of a turn. In fact, in the quarter turn in which one of the rotors is in contact with the insulating sector the current generated passes through the inductor and the load; in the subsequent quarter turn, in which both rotors are in contact with the conducting sector the load is shortcircuited and the current passes through the inductor only, thus increasing the magnetization. This continues through every quarter turn. ...continues