Showing papers in "Transactions of The American Institute of Electrical Engineers in 1902"

Three-Wire System for Variable Speed Motor Work

Abstract: A description of the operation of variable speed D.C. motors on the three-wire system. Illustrated.

Formula for Calculating the Electromotive Force at Any Point of a Transmission Line for Alternating Current

Abstract: It is a recognized fact that in long-distance transmission of electrical energy by means of alternating current, the voltage has often been found to be higher at the receiving end than at the generator end of the line. This increase in voltage may be considerable, and it is important to take it into account whern making installations. We intend to establish a formula giving the voltage at any point of an alternating current transmission line. Let us call p, r and A respectively, the resistance, capacity and self-induction per unit of length of both conductors of a line of length 1. Let

Methods of Speed-Control

Abstract: A consideration of the speed-control of shuntwound direct current motors. Applications of this type of motor to the operation of machineshop tools.

Edison's Tungstate of Calcium Lamp - The Nernst Lamp - Radium, Polonium and Actinium

Abstract: Threee topics are presented for discussion: Regarding the Edison lamp, the author presents several samples of what has been termed "Edison's X-ray lamp." This occasion is the first time that the lamp has been publicly exhibited. It is known that in connection with Mr. Edison's experiments with Roentgen rays, and in the construction of his fluoroscope, he experimented with thousands of chemical substances, and the substance which he found most suitable for use on the fluorescent screen was tungstate of calcium, which, together with barium platinum cyanide, constitute the substances most extensively employed in fluorescent screens. The author will operate one of the tubes that will serve to indicate to some extent the results of Mr. Edison's experiments in this direction. Regarding the Nernst lamp, the author presents tonight various types of American, English, German and Hungarian Nernst lamps, of both self-lighting and torch-lighting types. Some of the foreign types of lamps he described in detail in his article presented at the 151st general meeting of the INSTITUTE on Feb. 18, 1901; and the Westinghouse type of Nernst lamp has been presented by Alexander J. Wurts at the summer meeting of the INSTITUTE at the Pan-American Exposition at Buffalo. The author notes in passing the German Nernst lamps which are shown burning here this evening, and which are the latest types manufactured by the Allgemeine Electricitats Gesellschaft of Berlin. The large lamp containing the pendant conical heating coil is of a new type, which is here publicly presented for the first time. Finally, the author presents small quantities of radium being due to the interest which radium has excited in the scientific world, and as there are probably few in this audience to-night who have had an opportunity of seeing this remarkable, and up to the present time, exceedingly rare substance. Additional notes by M Curie are appended to the article.