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Siemens Gramme


Antonio  Pacinotti 


 Pisa 17.July.1841-Pisa 25.March.1912

1859 Dynamo


Physicist and mathematician. Still student, he devised between the first able apparatuses to produce to electric current by means of electromagnetic induction.   The device, than Pacinotti it described in a communication the “New one I try” in 1864, and called then “ring of Pacinotti”, it consisted essentially in a ring around which a copper thread was wrapped to spiral: the ring was free to rotate horizontally between the poles of a magnet or elettrocalamita.
For the phenomenon of electromagnetic induction, uncovered from M. Faraday in   1831, the rotatorio motion produced to an electric current in the thread, and, viceversa, the electric current passage in the thread made to rotate the ring, which, in such a way, acted as or from dynamo or from electric motor. 
Pacinotti,   lacking in a backing and engaged in the academic career, it did not know to take advantage of its invention commercially: the dynamo thus was constructed on industrial scale from Belgian Z.T., which Pacinotti had shown and described its apparatus during a visit in France.

This model is a copy originates of it them, than conserve still   in the University of Pisa and it was sent in homage from the same University to the School of Electrical engineering “Galileo Ferraris” of Turin   (prof. Fat) after the happened onoranze to Pacinotti during the International Exposure of 1911 to Turin, to which the same Pacinotti was present that, unfortunately, it died little months after.  It had already demonstrated, to the time of the first publication, than the machine he was reversible,   being able to work or from dynamo, or from motor, in order to transform the mechanical energy in electric power or viceversa.    The invention, resumption from the Gramme, that constructed in the 1871 first dynamo put in commerce,   it begins the age of the industrial electrical engineering.