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American Institute of Electrical Engineers, Proceedings of the

Issue 4 • Date April 1914

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Displaying Results 1 - 21 of 21
  • Institute meeting in Pittsburgh April 9–10, 1914

    Publication Year: 1914 , Page(s): 107 - 108
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  • Report of committee of tellers on nomination ballots

    Publication Year: 1914 , Page(s): 108 - 109
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  • Joint National committee on electrolysis

    Publication Year: 1914 , Page(s): 109 - 111
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  • Second Midwinter convention, New York, February 25–27, 1914

    Publication Year: 1914 , Page(s): 111 - 112
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  • Directors' meeting, New York, March 13, 1914

    Publication Year: 1914 , Page(s): 113 - 115
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  • Membership

    Publication Year: 1914 , Page(s): 115 - 124
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  • Past section meetings

    Publication Year: 1914 , Page(s): 124 - 129
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  • Personal

    Publication Year: 1914 , Page(s): 130
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  • Obituary

    Publication Year: 1914 , Page(s): 130 - 133
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  • Library accessions

    Publication Year: 1914 , Page(s): 133 - 134
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  • Officers and Board of Directors

    Publication Year: 1914 , Page(s): 135 - 145
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  • The development of the electric mine locomotive

    Publication Year: 1914 , Page(s): 517 - 528
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    The paper traces, largely by means of pictures, the course that has been followed in developing the mine locomotive to its present condition. The paper is limited to locomotives for operation in coal mines. The two main factors which have directed the development are, first, the demand for increased entry capacity, and second, the exploitation of thin seams. The early machines were high, and of irregular outline, whereas later machines are compact and strong, yet accessible, and easily inspected and overhauled. Various types of framing are illustrated. Locomotives with two and three axles in rigid wheel base, and also tandem locomotives are shown and described. Reference is made to various methods of connecting the motors by which the adhesive weight is used to full advantage. Gathering locomotives, with vertical and horizontal reels, both axle-driven and with independent electric drive, are illustrated, and some of the problems of gathering work are briefly discussed. There is also brief reference to various types of motors with different methods of lubrication, as well as some reference to sleeve vs. frictionless bearings. The paper closes with a few tendency curves, and attention is called to the lines of future development, which these curves apparently indicate. View full abstract»

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  • Theory of the corona

    Publication Year: 1914 , Page(s): 529 - 546
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    The theory of the corona developed in this paper explains the coronal discharge by the application of the known laws of the discharge of electricity through gases. The experiments of Dr. Whitehead and Mr. F. W. Peek and others have shown that the surface gradient Xs at the surface of a smooth wire necessary to start the corona increases very greatly as the radius of the wires decreases. As an illustration of this increase it is found that the coronal gradient Xs at the surface of a wire 0.5 cm. radius is 46,000 volts per cm., while a gradient of 97,000 volts per cm. is required for a wire of 0.02 cm. radius. The phenomenon is due to ionization by impact. The ions n0 move in toward the wire from the place at which they cross a region where the gradient is X0 = 26,600 volts per cm. up to the wire. They produce other ions, and n ions arrive at the wire. The condition for the corona is that n shall be a constant. If α = the number of ions that one ion produces in a cm., then n = n_{0} e^{\int^{b}_{a} \alpha ^{-}dx} The α is a function of X at every point. This function is expressed in terms of x. It is introduced into the above equation, and on integration the equation for the corona is obtained. The equation also contains a term for the density of the air. The equation thus takes account of changes of pressure such as altitude and temperature effects. The equation when plotted in a curve for the variation of Xs with the radius of the wire, agrees with the experimental results of Whitehead and Peek with as great accuracy as the experimental results would warrant. View full abstract»

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  • Some simple examples of transmission line surges

    Publication Year: 1914 , Page(s): 547 - 561
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    The paper treats of the true wave phenomena which take place on a transmission line when switches are opened and closed or when a circuit breaker operates. These phenomena are practically the same in alternating- and direct-current systems for transmission lines up to say 150 or 200 mi. (240 or 320 km.) in length, and therefore the surges which are described in the paper are the surges which take place when a steady voltage is connected to the line or when the line is disconnected with a steady current flowing in it. The details of line surging which takes place under such conditions are most easily described in terms of what may be called the “ribbon wave”, and the first part of the paper is devoted to a discussion of the ribbon wave. Then a number of practical examples are described in detail. View full abstract»

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  • Some investigations on lightning protection for buildings

    Publication Year: 1914 , Page(s): 563 - 579
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    A description is given of investigations conducted for a large manufacturer of explosives to determine upon a suitable system of lightning protection for buildings containing explosives. The work is divided into the following sections: (1) An analysis by oscillograph of the secondary currents induced by actual lightning discharges in vertical earthed conductors, the results seeming to indicate that such currents are non-oscillatory and aperiodic, though occurring in either a negative or positive direction. An attempt is made to explain the phenomena generally attributed to high frequency oscillations by the existence of uni-directional waves of almost vertical front. (2) An investigation of the primary effects of a 20-in. spark in air having the same essential characteristics as those attributed to lightning when applied to a model protective system consisting of isolated vertical conductors surrounding a small building. (3) An investigation of the secondary effects produced under the above conditions, which are considered to be static inductive rather than dynamic inductive. A brief description is given of a general protective system recommended for explosives buildings. View full abstract»

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  • Mine duty controllers

    Publication Year: 1914 , Page(s): 581 - 589
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    The paper is devoted to discussion of the advisable types of control to be used for various mining equipment, particularly in bituminous coal mines. Complexity and theoretical details have been eliminated as far as practicable with the idea of impressing on the reader the need for certain definite features, without going into the theoretical details of these features. Electric controllers for equipment outside of the mine proper as a rule have to meet different operating conditions than those controllers which are installed underground. The operating conditions are taken up in detail and proper control equipment is suggested to meet these conditions. The object of the paper is to bring out clearly to the mine operatives the fact that suitable control equipment is just as important as the installation of a suitable motor, and moreover that no motor, however well adapted to the service, will stand up properly if it is not operated with a controller designed and built specifically to meet the existing installation and operating conditions. View full abstract»

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  • Solenoids

    Publication Year: 1914 , Page(s): 591 - 623
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    Maxwell's law for the attraction between the halves of a bar electromagnet is not correct for electromagnets of the plunger type with air gaps between the cores because the flux in the cores is, to a large extent, independent of the reluctance in the air gap on account of the magnetic leakage from the inner end of either core back to the other end of the same core. In this paper, only the characteristics of direct-current electromagnets are discussed. An attempt is made to show the correct law of attraction for tractive electromagnets and to calculate the value of the magnetizing force at any point along the axis of any solenoid. Test characteristics are given to support the theories. The work done by an electromagnet of the plunger type in closing its air gap is largely proportional to the length of the air gap, although, when the reluctance of the air gap and the total m.m.f. are of low value, the law of Carichoff is approximately correct for the total attraction. View full abstract»

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  • A milliampere current transformer

    Publication Year: 1914 , Page(s): 625 - 639
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    (1) It is pointed out that by the use of a current transformer having a primary to secondary current ratio of the order of 1 to 100, oscillograms can be obtained of the charging current of a single high-tension insulator or of a few feet of high-tension transmission line; that is, oscillograms of currents of the order of 0.1 to 0.5 milliampere may be obtained. (2) The drawing and specification are given for a transformer for this purpose. (3) The transformer relations are discussed; the methods of determining the transformer constants are outlined, and the performance of transformers constructed in accordance with the specifications is determined. (4) A series of oscillograms is given to illustrate some of the applications of the transformer, such as to the study of corona, high-tension insulators, and leakage currents in evacuated lamps. View full abstract»

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  • Mine substations – I their construction and operation

    Publication Year: 1914 , Page(s): 641 - 653
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    The use of electricity in mines has been making rapid progress throughout the United States. Steam and compressed air are being superseded largely by central station power. Power from a central station requires a substation to supply direct current to operate locomotives, cutting machines, etc. A substation is used to transform high-voltage a-c. power to direct current at 250 or 500 volts. Substations, when possible, should be located on the surface, because if located underground there is danger from fire, and dampness weakens insulation and causes corrosion of metallic parts. Construction of an underground substation is more costly than on the surface, as there is danger of the roof giving way. The roof should be arched, or built of heavy concrete and the whole station made fireproof. When substations are located underground it is necessary to carry a high-tension cable through bore-holes. When located on the surface a low-tension cable can be used. Many accidents occur because of incompetent men. Good salaries should be paid and competent men obtained. Danger warnings should be posted and men taught to consider wires as being “live”, thereby lessening accidents. View full abstract»

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  • Self-contained portable electric mine lamps

    Publication Year: 1914 , Page(s): 655 - 667
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    The considerable number of mine explosions caused by defects of the Davy safety lamps has encouraged the development of electric lamps. Satisfactory results, however, have been obtained only since the invention of the tungsten lamp, permitting the use of smaller storage batteries. The general requirements for electric lamps are: absolute safety, uninterrupted production of light for at least one shift, and a foolproof design. Prizes offered by the British Government in 1912 for the best electric lamp, resulted in 197 different constructions being submitted. The first prize was awarded to a German lamp, which since that time has been used with great success all over Europe and which is also being introduced in this country. The construction of this lamp, consisting of several types for different requirements, and the methods of handling it in actual service, are fully described. Some figures covering repairs and renewals are given. In concluding, the author mentions the only objection that can be raised against electric portable mine lamps, that they cannot be used as detectors of mine gases, as Davy lamps can, and says that for this purpose devices distinctly separate from the lamp will have to be adopted. View full abstract»

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  • Discussion on “dynamo electric lighting for motor cars” (Waller), “advantages of clutch type generator and separate starting and lighting units for motor cars” (Churchward), and “electrical equipment of gasoline automobiles” (Conrad), New York, N. Y., November 14, 1913. (see proceedings for November, 1913)

    Publication Year: 1914 , Page(s): 668 - 691
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    H. Ward Leonard: I should like to put before the meeting what I think are a few of the desirable features we should strive to reach in an automatic lighting system for charging a storage battery and operating the lights upon a motor car, and I think the same conditions, so far as the automatic lighting and charging are concerned, may apply equally well to the case of train lighting. These are very broad generalities that I shall specify and while, in each case, they may have been already realized in some one of the various systems, I am not sure that there is upon the market at the moment any one system that contains them all. The points to which I refer are as follows: View full abstract»

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Aims & Scope

This Magazine ceased publication in 1919. The current retitled publication is IEEE Spectrum.

Full Aims & Scope