Mihajlo Idvorski Pupin - Pupin Coils

Pupin Coils

Its theory, today known as theory of pupinization, Pupin presented in the paper "Art of reducing attenuation of electrical waves and apparatus therefore" published in the Institute of Electrical Engineers on December 1899. This invention he patent is 19 June 1900. It represents a milestone in the development of international telephone traffic. Pupin patents were bought up immediately American Telephone & Telegraph (AT&T) and in Europe Siemens company and thus pupinization began a "triumphant way." The significance of this discovery will be reduced by thirty years later with the development of electronics, but pupinization is in some special cases used even today.

Pupin's 1899 patent for loading coils, archaically called "Pupin coils", followed closely on the pioneering work of the English physicist and mathematician Oliver Heaviside, which predates Pupin's patent by some seven years.

The importance of the patent was made clear when the American rights to it were acquired by American Telephone & Telegraph (AT&T), making him wealthy. Although AT&T bought Pupin's patent, they made little use of it, as they already had their own development in hand led by George Campbell and had up to this point been challenging Pupin with Campbell's own patent. AT&T were afraid they would lose control of an invention which was immensely valuable due to its ability to greatly extend the range of long distance telephones and especially submarine ones.

Pupin was among the first to replicate Roentgen's production of x-rays in the United States. He in 1896 invented the method of placing a sheet of paper impregnated with fluorescent dyes next to the photographic plate, thereby permitting an exposure of only a few seconds, rather than that of an hour or more.