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Showing papers in "Transactions of The American Institute of Electrical Engineers in 1909"


Journal ArticleDOI
TL;DR: In this article, it is shown that the metallic conduction at the ends of a wire can be eliminated by confining observation to parts of the wire not near the ends, and that lateral conduction through the air is also negligible, because the air does not remain at rest but expands and flows convectively.
Abstract: It is well known that when an electrically heated wire is supported in air, it dissipates its heat by conduction, radiation and convection. Conduction takes place longitudinally through and into the metallic terminals of the wire, and would take place laterally through the air, if the latter were kept at rest like a rigid medium. The metallic conduction at the ends may be eliminated by confining observation to parts of the wire not near the ends. The lateral conduction through the air is also negligible, because the air does not remain at rest but expands and flows convectively. Consequently we may safely ignore conductive thermal loss.

28 citations


Journal ArticleDOI
TL;DR: In this article, the object of the experiments recounted below was to establish a reliable and if possible a rational quantitative relation between the pole-face losses and the principal variables involved therein, which was originally undertaken as a small part of a larger investigation without any realizing sense of the amount of work involved or of the difficulty of obtaining reliable results.
Abstract: The object of the experiments recounted below was to establish a reliable and if possible a rational quantitative relation between the pole-face losses and the principal variables involved therein. The work was originally undertaken as a supposedly small part of a larger investigation without any realizing sense of the amount of work involved or of the difficulty of obtaining reliable results. Another time the method employed would be modified in the light of this experience, but although the results are not altogether satisfactory from the standpoint of the investigator, they are sufficiently accurate for most practical purposes, and it is believed more reliable than those heretofore published.

25 citations



Journal ArticleDOI
TL;DR: The object of the present paper is to discuss some of the features of the long line, more especially the line-output, regulation or voltage-variation, and the line energy-loss.
Abstract: The limitations of the power transmission line as to distance, power, and voltage, and its characteristics as to voltage-variation and energy-loss, have always excited a great deal of interest in the electrical art. The subject has been treated by a number of prominent engineers in its various phases, notable among these being Scott, Perrine, Steinmetz, and Mershon. These men and others have done pioneer work and have outlined the general limiting conditions of transmission. There are some of the relations and peculiarities of the long line, however, that are of importance and interest which have not, to the writer's knowledge, been clearly presented before electrical engineers. It is the object of the present paper to discuss some of these features, more especially the line-output, regulation or voltage-variation, and the line energy-loss.

22 citations





Journal ArticleDOI
TL;DR: In this article, it was shown that it is possible to use resistances to multiply the indications of the instrument, these resistances being used as shunts to the current coil or in the potential coils of voltmeters or wattmeters.
Abstract: Modern requirements make it necessary to measure alternating current, volts, and watts on circuits where the magnitude of these quantities and the safety of the operator require that some means be provided so that the instruments used are not directly connected to the circuit. In certain special measurements it may be found accurate and convenient to use resistances to multiply the indications of the instrument, these resistances being used as shunts to the current coil or in the potential coils of voltmeters or wattmeters.

11 citations


Journal ArticleDOI
TL;DR: A short review of the history of the high-frequency alternator can be found in this paper, where the authors give a short overview of the 10,000-cycle alternator.
Abstract: Before entering into a description of the form of generator dealt with in this paper, it may be of interest to give a short review of the history of the high-frequency alternator. Heretofore the 10,000-cycle machine has represented the highest frequency in commercial use. Such a machine was developed by one of the electrical manufacturing companies in 1900 and a number of them are now in service. A similar machine for 10,000 cycles was described by Lamme in a paper before the Institute in 1901.∗ Reference may be made particularly to a paper by Dudell read before the Physical Society of London, giving a synopsis of his work with this kind of apparatus and describing the experiments made by him.

9 citations


Journal ArticleDOI
TL;DR: In this paper, the authors discuss the calculation of the high-tension transmission line as relating to the important matters of regulation and energy line loss, and with especial reference to the unusually long and high-power lines.
Abstract: Neglecting matters of cost, the electrical performance of the high-tension transmission line becomes the critical factor as the quantity of power and distance of transmission become large. The loss and variation of voltage and, to a lesser extent, perhaps, the loss of energy in the line tend to become the dominating features. A careful study of these characteristics is thus most important in planning such a transmission. It is the purpose of the present paper to discuss the calculation of the high-tension line as relating to the important matters of regulation and energy line loss, and with especial reference to the unusually long and high-power lines. For this purpose certain new formulas suited for practical calculations are derived.

8 citations




Journal ArticleDOI
TL;DR: In this article, a short consideration of usual and special conditions, giving rise to even harmonics in alternating-current circuits, seems opportune, since we are so used to the mathematical expressions which omit the second, fourth, sixth, etc. harmonics.
Abstract: In the usual presentation and consideration of wave-forms in alternating-current circuits we are so used to the mathematical expressions which omit the second, fourth, sixth, etc. harmonics and so generally assume that these even harmonics can be neglected at the outset, that a short consideration of usual and special conditions, giving rise to even harmonics in alternating-current circuits, seems opportune.



Journal ArticleDOI
TL;DR: In this paper, the authors apply fractional pitch windings to alternating current generators, with an illustration taken from Bache-Wiig's Atlantic City paper on the “Application of Fractional Pitch Windings to Alternating-Current Generators”.
Abstract: The method of connecting the shape of the flux distribution curve of a synchronous converter with the shape of its induced electromotive force wave, developed by the writer in his Atlantic City paper,∗ is here applied more specifically to the alternator, with an illustration taken from Mr. Bache-Wiig's Atlantic City paper on the “Application of Fractional Pitch Windings to Alternating-Current Generators”. Parts of the explanation of the method are reproduced in a somewhat modified and condensed form for the benefit of those who did not read the other paper.

Journal ArticleDOI
TL;DR: The importance of modern telephone cable may be indicated by stating that of the 8,000,000 wires in the exchange plants of the Associated Bell telephone companies, more than 6,800,000 miles are in the form of underground, aerial, or submarine cable as mentioned in this paper.
Abstract: To those not closely in touch with the telephone situation to-day, the importance of the modern telephone cable may be indicated by stating that of the 8,000,000 miles of wire in the exchange plants of the Associated Bell telephone companies, more than 6,800,000 miles are in the form of underground, aerial, or submarine cable. These figures refer solely to the wire used for outside construction and do not include the thousands of miles of wire in cable form employed in central offices or the wiring of large buildings.

Journal ArticleDOI
TL;DR: The electric drive is utilized in ore unloaders, ore bridges, car dumpers, bin-filling cars, scale larries, blast-furnace skips, hot-metal mixers, electric cranes of all sizes and descriptions, open-hearth charging machines, ingot buggies, gas producers, roller tables, lifting tables, transfers, hotbed apparatus, etc. as mentioned in this paper.
Abstract: Introduction and historical. Twenty years ago electricity, except for lighting purposes, was virtually unknown to the iron and steel industries, while to-day in all of the steel works in this country it is used as a motive power for most of the auxiliary machinery, from the ore docks to the loading beds. The electric drive is utilized in ore unloaders, ore bridges, car dumpers, bin-filling cars, scale larries, blast-furnace skips, hot-metal mixers, electric cranes of all sizes and descriptions, open-hearth charging machines, ingot buggies, gas producers, roller tables, lifting tables, transfers, hot-bed apparatus — in short, a multitude of machines too numerous to mention here. This development has been such that it would probably be no exaggeration to say that the steel industry in this country would never have reached its present proportions without the use of electric motors. As a further gauge of progress, it is significant that the larger electric manufacturing companies have been forced to establish special departments to look after the business of the steel industries.

Journal ArticleDOI
TL;DR: In this paper, the authors define education as "the development of the intellect and the broadening of the mind, afforded by a general knowledge of all the subjects of interest to the human race, as required to enable a man to intelligently attack and solve problems in which no previous detail experience guides, and to decide the questions arising in his intellectual, social, and industrial life by impartially weighing the different factors and judge their relative importance".
Abstract: Education is not the learning of a trade or profession, but is the development of the intellect and the broadening of the mind, afforded by a general knowledge of all the subjects of interest to the human race, as required to enable a man to intelligently attack and solve problems in which no previous detail experience guides, and to decide the questions arising in his intellectual, social, and industrial life by impartially weighing the different factors and judge their relative importance. These problems, and thus the educational preparation required to cope with them, are practically the same in all walks of life, and the general education of mind and intellect, required by the engineer, the lawyer, the physician, etc., thus is essentially the same. The only legitimate differences in the training for the life's work, required by the different professions, thus are those pertaining to the specific instruction and study of the details of the particular branch of human knowledge, by which the student desires to make his living.




Journal ArticleDOI
TL;DR: In this article, the authors show that any differences in impedance and losses presented are undoubtedly due to the coiling and uncoiling and shipment of cables, as this would tend to change the relative air-gaps between the armor wires.
Abstract: Part I of this paper is supplementary to the paper by Professor Whitehead, because the data presented were obtained from measurements made on the same cables prior to Professor Whitehead's tests. The results given cover conditions mostly not considered by Professor Whitehead. Any differences in impedance and losses presented are undoubtedly due to the coiling and uncoiling and shipment of cables, as this would tend to change the relative air-gaps between the armor wires. Slight differences may also have been caused by small differences in the lengths of the cables tested, or by differences in temperature.



Journal ArticleDOI
TL;DR: In this article, the authors discuss the difficulties involved in the selection and arrangement of insulating materials for high-tension terminals in the case and the difficulty of bringing out the terminal wires through the case.
Abstract: The manufacture of apparatus for pressures of 88,000 volts or more resolves itself into the proper selection and arrangement of insulating materials. Of all the problems involved in this selection and arrangement, that of insulating the terminal wires where they pass through the case presents the greatest difficulty. When the terminal wires are carried through a metal cover the danger from breakdown is increased, yet the tendency of the latest designs is toward the use of metal tanks and covers. Even with present voltages the greatest difficulty lies in bringing out the terminal wires through the case. What may be termed “brute force” has characterized the proportioning of high-tension terminals up to the present time, as almost every class of insulating material in nearly every possible shape has been used to surround the conductor as it passes through the top of the case. The top itself has often been made of insulating material such as wood, simply to assist in insulating the lead.

Journal ArticleDOI
TL;DR: The economic problems which present themselves when the complex and far-reaching subject, Conservation of Natural Resources, is considered, can be approached best by first stating and defining them with reference solely to physical and economic facts and relations without reference to political boundaries or limitations as discussed by the authors.
Abstract: In any problem, accurate and, so far as practicable, concise statement is essential to proper consideration and correct solution. The economic problems which present themselves when the complex and far-reaching subject, Conservation of Natural Resources, is considered, can be approached best by first stating and defining them with reference solely to physical and economic facts and relations without reference to political boundaries or limitations. To approach the subject by considering, first, real or supposed difficulties imposed by the respective rights and duties of states and of the nation is to discuss method of treatment before diagnosis. We should consider the problem first as if there were no such thing as states within the union, assuming, for the time being, within the federal boundaries the existence of one central and absolute authority. The question what, upon this assumption is economically desirable, is that which the engineering profession should first agree upon and, if possible, state in a manner which will be understood by the general public.


Journal ArticleDOI
TL;DR: In this article, the authors call attention to certain features of hydroelectric work that are worthy of more general or more careful consideration than they have had heretofore, and present a survey of these features.
Abstract: The object of this paper is to call attention to certain features of hydroelectric work deserving of more general or more careful consideration than they have had heretofore.