Scientists index
Swan Galileo Ferraris

Lucien Gaulard

Paris 16.July.1850 - Paris 26.November.1888
1882 Transformer


Six February 1884 communicated to “Société française DES Electriciens” to have invented in 1882 apparatus constituted from two windings, in a position to varying the tension of a alternating current, or to increase it or to diminish it, with a yield of 90%. With the aid financial of J.Gibbs it succeeded to construct this apparatus, the transformer. It was introduced to the Exposure of London in 1883 and to the Exposure of Turin in 1884   
Secondary generator of Gaulard and Gibbs first type with rectilinear iron nucleus opened (1884)

Al Gaulard must to the introduction in the field of the industrial electrical engineering of the first efficient apparatuses for the transmission to remarkable distance of the electric power to alternating current, changing some, to appeals to, the two fundamental parameters, tension and current. These apparatuses, then sayings transformers, with the motor to rotating field of Galileo, began the development of the applications of the alternating currents that they constitute the base of the modern electrical engineering. The apparatus introduced here is that one on which G. Ferraris it experimented in 1884.    It still has the open iron nucleus.    The two windings are formed with rings plates of lastrina of copper, of   0,25 millimeter   of thickness,   cut to a sure point of the circumference and fortified of shelves to the two extremities.  The rings are enfilades over a nucleus of iron threads and isolated from the other by means of paper or a varnish.    The shelves of successive rings are moved along the external circumference so as to form a spiral.  The shelves of alternated rings are connected then metallically, practically the first one with the third party, this with fifth and thus via till the end of the column and the primary winding is obtained thus.  The secondary one is gained in the same way, connecting between they rings 2, 4, 6 and thus via;  this connection is arrested but to a quarter of the column and they are carried outside the two ends; it is resumed then with according to quarter of the column and thus via, of way that the secondary one remains subdivided in four sections, than can, to they time,   to connect in series or parallel between they, regarding the line of escape, by means of the disposed thorns on the forehead.      In such a way a current can be had on secondary a various tension and from those which they feed the head physician. In the present model the head physician has 455 rings, like the secondary one. Today the main defects of this apparatus can be found: great reluctance of the magnetic circuit iron-air;     insufficient the area of the section of the iron nucleus; weak person isolation between coils   in order to arrive to exercise tensions high; small relationship between the primary and secondary coil number,   also connecting all the groups of the secondary one in parallel.