Nicholas Tesla

(Smiljan, current Croatia, 1856 - New York, 1943) American physicist of Serbian origin. He studied at the universities of Graz (Austria) and Prague. After having worked in various electrical industries in Paris and Budapest, he moved to the United States (1884), where he worked under the command of Thomas A. Edison, then a supporter of continuous electric power. The incessant disputes with Edison forced its abandonment of the company and its association with George Westinghouse, who bought the patents of his motor and of a transformer that facilitated the distribution of this type of current towards the end users. Both won the battle of the distribution of energy, since the transport of alternating current is cheaper and simpler than that of continuous. In 1893 its system was adopted by the hydroelectric power station located in the Niagara Falls. Tesla founded an electrotechnical research laboratory in New York, where he discovered the principle of the rotating magnetic field and polyphase alternating current systems. He created the first AC induction electric motor and many other electrical devices such as the so-called Tesla assembly, a radio frequency transformer in which primary and secondary are tuned, useful when preselecting the input of a radio receiver. He predicted the possibility of making wireless communications in advance of the studies carried out by Marconi, and in his honor is called tesla the unit of measurement of the magnetic flux intensity in the international system. His inventions and patents followed one another quickly. In 1887, and as a result of the discovery carried out by John Hopkinson in 1880, according to which three alternating and out-of-phase currents can be transferred more easily than a normal alternating current, Tesla invented the three-phase induction motor. In this motor, the three phases act on the armature in such a way that the armature rotates when a rotating magnetic field is generated. However, the rotor moved with a certain delay with respect to the frequency of the current. Based on this invention, the Swedish Ernst Danielson created in 1902 the synchronous motor, in which he replaced the material of the armature, which was not magnetic, by a permanent magnet or electromagnet, which allowed him to get a motor that rotated with a number of revolutions per minute equal to the frequency of the current. In 1891 Tesla invented the coil that bears his name, which consists of a transformer consisting of a core of air and primary and secondary spirals in parallel resonance. With this coil he was able to create a field of high voltage and high frequency. Two years later he discovered the phenomenon of wave character called "Tesla light" in the alternating currents of high voltage and high frequency; by studying these currents, he observed that incandescent lamps of a single pole emit light when they are approached by a conductor through which electric current passes, and that the empty glass tubes shine although they lack electrode if they are connected by one of its ends and the other approaches a conductor through which high frequency current flows. He also realized that the human body is capable of conducting these high-frequency currents without experiencing any damage.