See Banu Musa ibn Shakir.
b. 27 July 1862 Neisse, Upper Silesia (now Nysa, Poland)
d. 18 January 1921 Berthelsdorf, Silesia
Ilgner graduated from the Gewerbeakademie (the forerunner of the Technical University) in Berlin. As the representative of an electric manufacturing company in Breslau (now Wroclaw, Poland) from 1897, he was confronted with the fact that there were no appropriate drives for hoisting-engines or rolling-plants in steelworks. Two problems prevented the use of high-capacity electric motors in the mining as well as in the iron and steel industry: the reactions of the motors on the circuit at the peak point of stress concentration; and the complicated handling of the control system which raised the risks regarding safety. Having previously been head of the department of electrical power transmission in Hannover, he was concerned with the development of low-speed direct-current motors powered by gas engines.
It was Harry Ward Leonard's switchgear for direct-current motors (USA, 1891) that permitted sudden and exact changes in the speed and direction of rotation without causing power loss, as demonstrated in the driving of a rolling sidewalk at the Paris World Fair of 1900. Ilgner connected this switchgear to a large and heavy flywheel which accumulated the kinetic energy from the circuit in order to compensate shock loads. With this combination, electric motors did not need special circuits, which were still weak, because they were working continuously and were regulated individually, so that they could be used for driving hoisting-engines in mines, rolling-plants in steelworks or machinery for producing tools and paper. Ilgner thus made a notable advance in the general progress of electrification.
His transformer for hoisting-engines was patented in 1901 and was commercially used inter alia by Siemens & Halske of Berlin. Their first electrical hoisting-engine for the Zollern II/IV mine in Dortmund gained international reputation at the Düsseldorf exhibition of 1902, and is still preserved in situ in the original machine hall of the mine, which is now a national monument in Germany. Ilgner thereafter worked with several companies to pursue his conception, became a consulting engineer in Vienna and Breslau and had a government post after the First World War in Brussels and Berlin until he retired for health reasons in 1919.
b. 30 March 1894 Dilyalevo, Vologda, Russia
d. 9 February 1977 Moscow, Russia
In 1914 he joined the Russian army, later transferring to the air service and gaining his pilot's licence in 1917. After fighting in the Red Army during the Civil War, he entered the Zhukovsky Air Force Engineering Academy in Moscow in 1922, graduating four years later. He joined the Engineering Technical Corps of the Red Air Force as a designer and eventually rose to the