In the 1832, the French Bixi invented the hand-cranked DC generator, the principle of which is to generate an inductive electromotive force in the coil by rotating the permanent magnet and outputting the electromotive force in the form of DC voltage;
In 1866, Siemens, Germany, invented the self-excited DC generator;
In 1869, a ring armature was made by the Belgian Gramm, and a toroidal armature generator was invented. This kind of generator is water force to rotate the generator rotor, after repeated improvement, in 1847 obtained 3.2KW output power;
1882, the United States of Gordon produced output power 447KW, 3 meters high, weighing 22 tons of two-phase giant generators;
In 1896, Tesla's two-phase alternator began working in the Nyala power plant, and 3750kw,5000v's alternating current was sent to Buffalo, 40 kilometres away.