Showing papers in "Transactions of The American Institute of Electrical Engineers in 1934"
TL;DR: Discussion of a paper by H. S. Black published in the January 1934 issue, p. 114–20, and presented for oral discussion at the communication session of the winter convention, New York, N. Y., Jan. 24, 1934.
Abstract: This paper describes and explains the theory of the Feed-back principle and demonstrates how stability of amplification, reduction of modulation products, and certain other advantages follow when stabilized feed-back is applied to an amplifier. The underlying principle of design by means of which ``singing'' is avoided also is set Forth. The paper concludes with some examples of results obtained on amplifiers which have been built employing this new principle.
72Â citations
Journal Article•
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TL;DR: In this paper, the authors reviewed some of the more important observations and conclusions obtained from investigations in the field of electron emission from hot cathodes, including the so-called Edison effect.
Abstract: Edison's observation of the discharge of negative electricity from the carbon filament of an incandescent lamp to an auxiliary electrode in the bulb, commonly known as the ``Edison effect,'' remained unexplained until the beginning of the 20th century. Since that time, an entire new industry?radio?has grown up as a result of continued research in the emission of electrons from hot cathodes. This article, seventh of a series prepared under the sponsorship of the A.I.E.E. committee on education, reviews some of the more important observations and conclusions obtained from investigations in this field.
52Â citations
TL;DR: In this paper, a series of basic field tests was conducted on both the parallel insulated counterpoise and the buried counter-poise, and the results of these tests were analyzed, and conclusions were drawn.
Abstract: Different theories have been advanced as to the behavior of the counterpoise in the protection of power transmission lines against lightning. In an attempt to learn more about the counterpoise and to check the theories of its behavior, a series of basic field tests was conducted. The results of these tests, made on both the parallel insulated counterpoise and the buried counterpoise, are reported in this paper. The data obtained are analyzed, and conclusions are drawn.
45Â citations
39Â citations
TL;DR: In this paper, the mathematical relations governing their operation and several applications are discussed, including the use of the lines as circuit elements in the ultra-short wave range as a means of obtaining high impedance with low loss, where the lines may be either concentric tubes or 2 wires, and are sufficiently small that they may be placed within the apparatus.
Abstract: Resonant transmission lines may be used as circuit elements in the ultra-short wave range as a means of obtaining high impedance with low loss. The lines may be of either concentric tubes or 2 wires, and are sufficiently small that they may be placed within the apparatus. These circuits can be made highly selective, and when used to control oscillator frequency will give stability comparable to that of a crystal. The mathematical relations governing their operation and several applications are discussed in this paper.
35Â citations
TL;DR: In this paper, a new type of motor in which a scheme involving electronic tubes is used to perform a function similar to that of a commutator is described, which operates at variable speed and is supplied from a 3-phase power system.
Abstract: A new type of motor in which a scheme involving electronic tubes is used to perform a function similar to that of a commutator is described in this paper. The motor operates at variable speed and is supplied from a 3-phase power system. A 400-hp motor of this type has been built and is ready For commercial use.
28Â citations
TL;DR: In this paper, the rectifier and inverter characteristics of the grid controlled mercury arc rectifier o the 6-phase and 12-phase types are considered and the analysis of rectifier circuits has been extended to cover the effect of grid control on the output voltage, power factor, eficiency, wave forms, and other characteristics.
Abstract: The rectifier and inverter characteristics of the grid controlled mercury arc rectifier o the 6-phase and 12-phase types are considered in this paper. The analysis of rectifier circuits has been extended to cover the effect of grid control on the output voltage, power factor, eficiency, wave forms, and other characteristics; and the characteristics of the grid controlled rectifier operating as an inverter have been determined. Several schemes for applying these rectifiers to railway electrification requiring regeneration are considered.
25Â citations
TL;DR: In this paper, some of the more important technical problems involved in connecting rotating machines directly to overhead electric power transmission lines are discussed, and methods are developed for protecting the ground and turn insulations.
Abstract: Some of the more important technical problems involved in connecting rotating machines directly to overhead electric power transmission lines are discussed in this paper. Methods are developed for protecting the ground and turn insulations Protecting the ground and turn insulations of the armatures of such machines which may be subjected to surge voltages. The ground insulation can be protected by lightning arresters; the turn insulation by sloping off the incoming surge. Methods sloping off the incoming surge. Methods are given for determining the maximum allowable rate of rise of voltage at the machine terminals, and the apparatus needed to limit the rate of rise to that value.
25Â citations
25Â citations
22Â citations
TL;DR: In this paper, it is shown that good auditory perspective can be obtained with only 2 or 3 channels, and this is the second paper in the symposium, where the authors defined the auditory perspective as being reproduction which preserves the spatial relationships of the original sounds.
Abstract: In considering the physical Factors affecting it, auditory perspective is defined in this paper as being reproduction which preserves the spatial relationships of the original sounds. Ideally, this would require an infinite number of separate microphone-to-speaker channels; practically, it is shown that good auditory perspective can be obtained with only 2 or 3 channels. This is the second paper in the symposium.
TL;DR: In this article, the efect of magnetic saturation is included in the derivation of the equations for determining steady state performance of synchronous machines, and it is shown that a saturated machine under steady state conditions, and for small changes from the original operating point, can be replaced for purposes of calculation by an unsaturated machine.
Abstract: Steady state characteristics of synchronous machines of normal design are affected appreciably by changes in magnetic saturation. In this paper the efect of saturation is included in the derivation of the equations for determining steady state performance. It is shown that a saturated machine under steady state conditions, and for small changes from the original operating point, can be replaced for purposes of calculation by an unsaturated machine.
TL;DR: In this paper, the authors discussed the effects of overloading on the life of self-cooled power transformers and showed that under average loads and ambient temperatures, a transformer rated for a temperature rise of 55 degrees C, has a very long life, and can be overloaded considerably for short periods with little loss in life.
Abstract: Efects of overloading on the life of oilimmersed self-cooled power transformers are discussed in this paper. Experience has shown that under average loads and ambient temperatures, a transformer rated for a temperature rise of 55 degrees C, has a very long life, and can be overloaded considerably for short periods with little loss in life.
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TL;DR: In this article, an outline of some of the methods employed in dealing with stationary fields is presented, conjugate functional methods and conformal representation being considered in detail, preceded by a brief consideration of experimental reproduction, graphical mapping, and mathematical solutions of field problems.
Abstract: Field theory, as contradistinct to circuit theory, is shown in this article to become increasingly important in a large number of engineering problems. In addition to the more familiar electric and magnetic fields there are temperature, mechanical stress, hydraulic flow, and other field concepts all reducible to the same mathematical basis. An outline of some of the methods employed in dealing with stationary fields is presented in this paper, conjugate functional methods and conformal representation being considered in detail, preceded by a brief consideration of experimental reproduction, graphical mapping, and mathematical solutions of field problems. This is the twelfth of a series of special articles developed under the sponsorship of the A.I.E.E. committee on education.
TL;DR: In this article, the solution of the more commonly used impulse generator circuits is developed and summarized, and the results of the circuit constants calculated by these formulas check closely the waves actually recorded by the cathode ray oscillograph.
Abstract: With impulse voltage testing of electrical equipment becoming more widely used, it seems highly desirable to be able to calculate the circuit constants required to produce the desired test waves and to calculate the waves that any given circuit constants will give. In this paper the solution of the more commonly used impulse generator circuits is developed and summarized. Waves calculated by these formulas check closely the waves actually recorded by the cathode ray oscillograph.
TL;DR: A glow discharge at atmospheric pressure is responsive to air velocity, and may be used as an anemometer as discussed by the authors, and data relating to glow current, voltage, glow length, and air velocity are presented.
Abstract: A glow discharge at atmospheric pressure is responsive to air velocity, and may be used as an anemometer. The properties of such a glow are discussed in this paper, and data relating to glow current, voltage, glow length, and air velocity are presented. It is also shown that the glow discharge responds to rapid fluctuations in air velocity and is therefore a practical device for investigating turbulence. A comparison of such an anemometer with the previously used hot wire method is given.
TL;DR: In this article, the high velocity streams of particles in the vacuum arc have been subjected to a detailed study, and the results are presented in this paper, together with a discussion of many of the phenomena involved.
Abstract: The high velocity streams of particles in the vacuum arc have been subjected to a detailed study, and the results are presented in this paper, together with a discussion of many of the phenomena involved. Experimental determinations of the relations between arc current, mass of condensed metal, electrodes, and velocity of the vapor stream are included. Results with several different electrode materials are presented.
TL;DR: In this article, the effect of the shape of electrodes has on the dielectric strength of air when subjected to impulse and 60 cycle voltage waves is considered, and principal attention is given to rod and plate electrodes.
Abstract: The effect that the shape of electrodes has on the dielectric strength of air when subjected to impulse and 60 cycle voltage waves is considered in this paper. Principal attention is given to rod and plate electrodes and to sphere and plate electrodes, comparative data on the different types being given. Among other factors, the effect of polarity on breakdown voltage is brought out. These data on strength of air between various electrode shapes are correlated into working principles and presented from the standpoint of the design engineer interested in their application.
TL;DR: In this article, the reasons why this curve deviates from a straight line are discussed, and a method of attacking the problem is given, and results calculated by this method for a number of machines are compared with the tested results.
Abstract: Predetermination of the bend in the locked saturation curves of squirrel cage induction motors is becoming increasingly necessary for design. The reasons why this curve for design. The reasons why this curve deviates from a straight line are discussed in this paper, and a method of attacking the problem is given. Results calculated by this method for a number of machines are compared with the tested results. It is shown that the work involved in using the formulas and curves presented is not excessive.
TL;DR: A loading-back test has been used for the determination of the stray load losss in polyphase induction machines as discussed by the authors, which was found to have a high degree of accuracy, enabling the various losses to be separated.
Abstract: A loading-back test has been used for the determination of the stray load losss in polyphase induction machines. This test, which was found to have a high degree of accuracy, enables the various losses to be separated. The application of the test is simple and convenient.
TL;DR: In this paper, a series of sparkover voltage calibration tests on sphere gaps using spheres of various sizes up to 200 cm in diameter are reported and recommended for the adoption of separate calibration curves for positive and negative impulses and for correcting the 60-cycle calibration curves of large spheres.
Abstract: A series of sparkover voltage calibration tests on sphere gaps using spheres of various sizes up to 200 cm in diameter are reported in this paper. Tests were made with gap spacings ordinarily used in pratice, and with 60-cycle and both positive and negative impulse voltages. Since these tests as well as those of other investigators show that some of the A.I.E.E. standard sphere gap calibration curves are in error, it is recommended that those standards be revised. Recommendations are made for the adoption of separate calibration curves for positive and negative impulses and for correcting the 60-cycle calibration curves of large spheres.
TL;DR: The A.I.E. transformer subcommittee as mentioned in this paper proposed an extension of the scope of the Institute publication relating to the operation of transformers to include recommendations for the short-time overloading of oil-immersed transformers in service.
Abstract: The A.I.E.E. transformer subcommittee* has planned an extension of the scope of the Institute publication relating to the operation of transformers to include recommendations for the short-time overloading of oil-immersed transformers in service. These recommendations take advantage of the heat storage capacities of the materials of the transformer to supplement present recommendations relating to the continuous overloading that is possible when the ambient temperature is lower than the standard ambient temperature. This report gives a brief review of the considerations upon which the proposed changes are based and includes the new material in the form in which the subcommittee has prepared it. it is submitted to the Institute for constructive criticism.
TL;DR: In this description of the manufacturing processes for suspension insulators, from design and research to finished product, is given a comprehensive list of the laboratory equipment required for adequate testing.
Abstract: In this description of the manufacturing processes for suspension insulators, from design and research to finished product, is given a comprehensive list of the laboratory equipment required for adequate testing. Methods of testing for defects and the manner of assembly are sketched, and the need for further standardization is mentioned.
TL;DR: Petersen coils installed on part of a 140kv transmission system operating with the neutral ungrounde have successfully eliminated a large percentage of interruptions due to line-to-ground faults which occurred on that section as mentioned in this paper.
Abstract: Petersen coils installed on part of a 140-kv transmission system operating with the neutral ungrounde have successfully eliminated a large percentage of interruptions due to line-to-ground faults which occurred on that section Detailed tests, presented in this paper, also have been made, and indicate many characteristics of the Petersen coil system
TL;DR: In this paper, the dielectric properties of pure cellulose paper as used for high voltage insulation are reported, including phase difference and capacitance of paper insulated specimens as related to the moisture content of the paper.
Abstract: Studies of the dielectric properties of pure cellulose paper as used for high voltage insulation are reported in this paper. The studies reported in Part I, presented herewith, include investigation of the dielectric loss, phase difference, and capacitance of paper insulated specimens as related to the moisture content of the paper. In Part II, which is scheduled for publication in a subsequent issue, these studies are extended to the variations in dielectric properties as related to temperature when the paper is extremely dry.