It perfectly illustrates the technological transition phase between steam use, the main energy source at the beginning of the industrial age, and electricity, corresponding to the second industrial period.
The furnaces produced steam at a pressure of 12 bars that operated four pistons of the steam machine contained in the four cylinders: high-pressure, medium-pressure and 2 low-pressure cylinders.
The movement of the pistons, transmitted by connecting arms and crank arms, sets off the alternator's giant wheel. The wheel also acts as a flywheel: its mass stabilizes the machine's movement... It provides alternative current by way of its 72 electromagnets, which were powered by direct current from a direct current generator called an exciter. The poles of the electromagnets are alternated: one north, one south...
When the wheel, which is the alternator's rotor, turns, the rapid changes of the magnetic field in front of the fixed component - the stator - generate an alternative current in its copper armatures. The alternator then produced a 900 KW electrical current with a voltage of 400 V and a frequency of 45, then 50Hz as of 1922.