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American Institute of Electrical Engineers, Journal of the

Issue 2 • Date Feb. 1922

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Displaying Results 1 - 25 of 25
  • Printing telegraph systems applied to message traffic handling

    Page(s): 79 - 91
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    Ever since the building of the first practical automatic telegraph instruments by Vail in America in 1837, and Wheatstone in England in 1841, an ever-increasing amount of the world's high-speed communication has been carried on by the printing telegraph. While these early machines were built primarily for the use of the European Government Telegraphs or the large American telegraph companies, the developments of the last few years have produced an instrument which is a practical working tool for the service of modern commercial and industrial enterprises. This paper discusses some of the economic principles which determine the applicability of the automatic printing telegraph to present-day communication problems. Examples are given of the application of this type of apparatus to modern business conditions and the fundamental fact is demonstrated that whenever speed is essential in communication, consideration should be given to the automatic printing telegraph. The discussion is limited to those forms of light traffic load printing telegraph systems which have been developed particularly for linking together the departments of the factory, the terminal points of the railroad, the branches of the banking, the brokerage or the selling organization or the units of any other large corporation. A description is then given of the principle of operation of three such systems, somewhat in detail, as there is very little literature on the subject. View full abstract»

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  • The effects of moisture on the thermal conductivity of soils: With a bibliography on the heating of cables

    Page(s): 92 - 98
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    It has been appreciated for many years that the presence of moisture in the soil surrounding underground cable was of assistance in dissipating the heat generated within the cable. But little was definitely known, however, of the exact changes in the thermal conductivity of soils caused by the presence of moisture. The following article shows that moisture plays a predominant part. The relative thermal conductivity of various types of perfectly dry soils, such as sand, clay, gravel, etc., covers a range from only one to two, while the addition of moisture increases the range to five times or more that of dry soils. The article also includes a bibliography on the heating of underground cables, giving reference to 59 papers on the subject in English, French and German. View full abstract»

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  • On deviations from standard practise in lightning arresters

    Page(s): 99 - 106
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    This paper is an endeavor to answer questions of practise and criticism of arresters brought out by an investigation conducted by the Protective Devices Committee. For the most part practise in lightning arresters is standardized. In fundamental principles there have been no changes for many years. Improvements in details, especially of construction, are still being made. A new arrester, the oxide film arrester, gets rid of the oil and electrolyte and avoids the necessity of daily charging, but fundamentally it is designed along the same principles as the aluminum arrester. The important principle is the electric valve action — there are but a few milliamperes of discharge rate at normal line voltage, but at abnormal line voltages the discharge current rise to hundreds of amperes. In answer to criticisms made by a few prominent engineers, it is maintained as fundamental that a large discharge rate for an arrester is an absolute essential. The burden of proof falls on those engineers who use arresters of low discharge rate. These arresters cannot discharge the dangerous lightning surges on overhead lines. Since there are lightning arresters of low discharge rate in apparently satisfactory use, an explanation for this anomaly is found in the use of insulators of low arc-over voltage. Either the lightning potential is relieved locally at the insulator or the resultant traveling wave is of too low voltage when it reaches the transformer greatly to endanger the insulation. Poor line insulation is not a solution of the problem of continuity of service. Why not save the cost of the useless lightning arrester? The current in such a traveling wave is about two amperes for every thousand volts of lightning potential, 600 amperes for 300 kv. One to twenty-five ampere discharge rate of arresters has little effect in reducing the lightning voltage. How many arresters should be used, to protect a six-feeder system? It depends on the conditions of insulation in circuit br- akers and the importance of continuity of service. According to the conditions discussed in the body of the paper, from one arrester connected to the busbars to seven arresters with auxiliaries are needed. The use of no arresters is discussed from three standpoints. 1. If it is contended that lightning is not of sufficient voltage to cause damage. 2. If it is considered a better investment to put lightning arrester money into spare transformers. 3. If it is considered good practise to so highly insulate a transformer as to give it immunity from lightning. The conclusion reached is that each of these three arguments is dangerously faulty. A new method of inspection of aluminum arresters is proposed. The experiments given in the paper show that the power factor of the cells examined is very sensitive to their condition. There are promises of effecting economies in overhauling aluminum arresters and of lengthening their life. Experiences are given with a 33-kv. arrester in service thirteen years without overhauling. The plates are still in good condition. The usual damaging deposits of decomposed oil on the aluminum film were prevented by using an initial rush of charging current great enough to throw them off. The electrolyte is partially exhausted in strength and needs changing. The discharge rate is still high. View full abstract»

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  • The “Indumor”: A kinematic device which indicates the performance of a polyphase induction machine

    Page(s): 107 - 117
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    A kinematic device is described and illustrated which represents the vector diagram of a polyphase induction machine. The parts are made to assume at will different positions corresponding to different loads of an induction motor or generator. The primary and the secondary constants, the magnetizing current, and the core loss, are also adjustable at will. The device permits the visualization of the performance of an induction machine and can be used for a study of a given machine or for a selection of the constants to give the desired performance characteristics of a new machine. The input, output, torque, speed, power factor, etc., can be read off on the device as in an actual brake test. The kinematic connections consist mainly of generalized proportional dividers and of parallel tongs, so combined as to satisfy a system of simultaneous vectorial equations which represent the properties of the machine. Further applications of the device to polyphase commutator motors are suggested. View full abstract»

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  • Submarine cable telegraphy

    Page(s): 118 - 136
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    The history of the development of the subject is first outlined, and methods of operation of cables are described. The technical side is introduced with a statement of the various conditions which limit operation of cables, and a general method of analysis is developed, based upon an extension of ordinary alternating-current theory. The theory is made use of to analyze the action of cable types and of apparatus which at this time can be regarded as standard. The fundamental theory of the method of analysis, with information on the calculation of transients in electrical circuits, is given in the Appendix. View full abstract»

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  • Energy front of electric circuits

    Page(s): 136 - 137
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    AS there has been recently some discussion of the position of the energy front in an electric circuit, and as this discussion mainly consisted in quoting mathematical authorities against each other, it may be of interest to the reader who does not care to go into the mathematics of it, to discuss in non-mathematical terms the energy travel in the space surrounding a conductor carrying electric current. View full abstract»

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  • Five hundred tests on the dielectric strength of oil

    Page(s): 138 - 139
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    While developing a dependable method of taking experimental data with a sphere gap in transit oil, considerable study was made of the behavior of oil under disruptive dielectric stress. The following notes on the dielectric strength of oil are offered as evidence that the nature and character of the dielectric breakdown of oil may be entirely different from that of air. Five hundred successive breakdowns were taken on a sphere-gap in oil at the same gap setting. Because of the well known inconsistency of breakdowns in oil these observations showed wide variation. A curve was plotted to show the relation between the breakdown voltage and the number of breakdowns at each voltage. If the disruptive breakdown of oil is due to the voltage exceeding the dielectric strength of the oil, as is the case with air, it should be possible to represent such a curve of probable error, or “probability curve” as it is usually called, by an exponential equation. In the following paper this is seen to be impossible, the most representative exponential curve being higher than the observations at higher voltages. The explanation is offered that this discrepancy is caused by foreign particles of low dielectric strength being drawn into the gap and that therefore the dielectric strength of oil differs from that of air in that it does not represent the true breakdown value of the oil but is instead a measure of the presence of foreign particles in the oil. View full abstract»

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  • The Petersen earth coil

    Page(s): 140 - 148
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    Accidental arcing grounds on transmission lines constitute the foremost problem to be solved in the transmission of electrical energy over great distances. There has come into use to a limited extent, arcing ground suppressors. This device consists in principle, of a switch in the station which is automatically closed in parallel with the accidental arc at any point out on the system. The parallel path through the switch shunts the current from the arc and thereby extinguishes the arc. This development is not yet completed. This paper gives the results of some experiments on an entirely different device for suppressing accidental grounds — a device that was first advocated by Prof. W. Petersen of Darmstadt, Germany. The essential part of this new apparatus is a suitable reactor connected between the neutral of the circuit and ground. This reactance is chosen of such a value as to neutralize the capacitance of the circuits when an accidental ground of one phase takes place. Under this accidental condition the reactor is electrically in parallel with the active capacitances and, by the well-known fundamental law, the only current that flows to the combination of the inductance and capacitance in parallel is the current necessary to supply the energy loss in the combination. The simplified equivalent conditions are shown in Fig. 4. This energy current can be made very small and it is this relatively small current that passes through the accidental arc to ground. If the ground is of the arcing type, the arc will, under favorable conditions be extinguished, as the energy flowing through the fault is only that necessary to supply the losses in the resonant circuit. If the losses are low, the energy flowing through the fault will be insufficient to support an arc and the voltage of the resonant system is gradually reduced to zero, while the voltage between the former faulty wire and ground gradually rises to normal value. In a comparison of the various methods of - rounding and their effects on the operation of a power system, the solid and the low-resistance grounds assume first and second place in the order of desirability. The distinction however, between these two is slight and choice will be determined by local conditions. Either the Petersen earth coil or the critical-resistance ground will assume third place in the order of desirability as the relative advantages and disadvantages of these two are about equal. The advantages of the Petersen earth coil system are: first, the suppression of arcing grounds under favorable conditions; second, the reduction of insulator trouble; and third, small earth current when a fault occurs to ground. The disadvantages are: first high potentials between line and ground due to series resonance; second, maintenance of a series of arcs under unfavorable conditions, that is, resonance and high loss, or large dissonance and either high or low loss; third, difficulty in obtaining selection of the faulty line by means of relay protection; fourth, reduced lightning protection due to the necessity of high settings on arresters; and fifth, increased system insulation due to the shifting of the neutral with abnormals or transients. View full abstract»

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  • Illumination items: By the lighting and illumination committee

    Page(s): 149 - 150
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    Dr. P. W. Cobb, of the Nela Research Laboratory, has just made public a preliminary report upon some experiments which he undertook for the purpose of obtaining a fundamental idea of the influence of levels of illumination upon the speed of vision, and ultimately, if possible, of determining the exact relation existing between these two things. While these experiments make certain assumptions which have not yet been experimentally tested and technical application of the results are therefore not warranted at the present time, Dr. Cobb's investigations clearly show that there is a general relation between speed of vision and illumination intensities, and indicate that this relation is different for different individuals. The following is an abstract of Dr. Cobb's report on these experiments. View full abstract»

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  • Electric sign lighting

    Page(s): 150 - 151
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    That a new era in sign lighting is on in earnest is evidenced by the rapidly increasing number of new, bigger, and brighter electric signs in all parts of the country. There is hardly a city or town of any size in which the residents have not experienced real thrills from gazing upon one or more recently-installed, attractive, interest-compelling electric signs. Whether located in the world-famous white-light district of Broadway, or over the door of the general merchandise store on Main Street in a small town, the brighter electric signs shine forth at night and burn their glowing messages into the minds of all passers-by with great effectiveness. View full abstract»

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  • Higher illumination standards advocated as aid to defective vision

    Page(s): 151
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    The report of the Committee on Elimination of Waste in Industry of the American Engineering Council on “Accidents Due to Eye Defects” contains some very interesting observations regarding the prevalence of defective vision as found in the industries today. It stresses the importance of correcting subnormal vision among employees, insisting that excess eye fatigue results in conditions which must produce loss, due to lowering the quantity and quality of whatever is produced. Subnormal vision was found to be of great frequency. One investigation showed that out of 2,906 garment workers only 743 or a little over 25 per cent had normal vision in both eyes, 17 per cent having normal vision in one eye with the other eye defective. The highest percentage of defective vision was in the class of workers who made the greatest use of their eyes. View full abstract»

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  • Electric power application to passenger and freight elevators

    Page(s): 152 - 164
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    THE elevator controller is one of the most important and at the same time perhaps the most complicated part of the equipment as it provides many of the safety features. The smooth operation of the elevator car is largely dependent upon its functioning, and the design affects the power consumption to a marked degree. Considerable economy can be obtained by selecting the best type for each particular application. View full abstract»

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  • Capacity effects in inductance coils

    Page(s): 164
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    A coil of wire wound in any of the familiar forms called “inductance coils” behaves in an electric circuit primarily as an inductance. The potentials of the different parts of the coil are, however, different from each other and from the potential of the ground. For this reason, the coil also behaves to a certain extent as an electric condenser, or rather a system of condensers. View full abstract»

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  • A. I. E. E. Midwinter convention

    Page(s): 27 - 28
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    The tenth annual Midwinter Convention of the American Institute of Electrical Engineers will be held February 15–17, 1922, in the Engineering Societies Building, 33 West 39th Street, New York, N. Y. This will be the first convention to be held under the new ruling of the Board of Directors which prescribes but four general technical meetings of the Institute to be held each year. Owing to this reduced number of general meetings an unusually large attendance is anticipated and every effort is being made to make this meeting of particular interest. View full abstract»

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  • American Engineering Council

    Page(s): 29 - 31
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    The first Annual Meeting of the Federated American Engineering Societies was held at the Cosmos Club, Washington, January 5th and 6th. View full abstract»

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  • Associated technical societies of Detroit founded

    Page(s): 31 - 32
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    After several years of thought and discussion along similar lines, the movement for the affiliation of the architectural, engineering and other technical societies of Detroit was taken up seriously in June 1921 by the organization of a Temporary Council composed of two delegates from each of the several societies interested. The affiliation has become an accomplished fact, taking effect January 1, 1922, by the ratification of the proposed Constitution and By-Laws, acceptance of membership and election of Councellors by the following twelve societies: Detroit Section, American Society of Civil Engineers; Detroit Chapter, American Association of Engineers; Michigan Chapter, American Society of Heating and Ventilating Engineers; Detroit Post, Society of American Military Engineers; Detroit Section, American Society of Mechanical Engineers; Detroit-Ann Arbor Section, American Institute of Electrical Engineers; American Institute of Chemical Engineers; Detroit Engineering Society; American Chemical Society and Detroit Chemists; Michigan Chapter, American Institute of Architects; Detroit Section, Michigan Society of Architects; Detroit Chapter, American Society of Steel Treating. View full abstract»

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  • Personal mention

    Page(s): 32 - 33
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    Paul Liunge, of the engineering department of the New York Edison Company, has sailed for Denmark for several months' stay. View full abstract»

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  • Obituary

    Page(s): 33 - 34
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    Freely Available from IEEE
  • Engineering societies library

    Page(s): 34 - 35
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    The library is a cooperative activity of the American Institute of Electrical Engineers, the American Society of Civil Engineers, the American Institute of Mining and Metallurgical Engineers and the American Society of Mechanical Engineers. It is administered for these Founder Societies by the United Engineering Society, as a public reference library of engineering and the allied sciences. It contains 150,000 volumes and pamphlets and receives currently most of the important periodicals in its field. It is housed in the Engineering Societies Building, 29 West Thirty-ninth St., New York. In order to place the resources of the Library at the disposal of those unable to visit it in person, the Library is prepared to furnish lists of references to engineering subjects, copies or translations of articles, and similar assistance. Charges sufficient to cover the cost of this work are made. The Director of the Library will gladly give information concerning charges for the various kinds of service to those interested. In asking for information, letters should be made as definite as possible, so that the investigator may understand clearly what is desired. The library is open from 9 a. m. to 10 p. m. on all week days except holidays throughout the year except during July and August when the hours are 9 a. m. to 6 p. m. View full abstract»

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  • Addresses wanted

    Page(s): 35
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    A list of members whose mail has been returned by the Postal Authorities is given below, together with the addresses as they now appear on the Institute records. Any member knowing the present address of any of these members is requested to communicate with the Secretary at 33 West 39th Street. View full abstract»

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  • Past section and branch meetings

    Page(s): 36 - 38
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    Freely Available from IEEE
  • Employment service Bulletin

    Page(s): 39 - 41
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    OPPORTUNITIES. — Desirable opportunities for service from responsible sources are announced in this Bulletin, and no charge therefor is made. MEN AVAILABLE. — Under this heading brief announcements (not more than fifty words) will be published without charge to the members. Announcements will not be repeated except upon request received after a period of three months, during which period names and records will remain in the active files. NOTE. — Notices for the JOURNAL should be addressed to EMPLOYMENT SERVICE, 33 West 39th Street, New York, N. Y., the employment clearing house of the Societies constituting the Federated American Engineering Societies, and not to the A. I. E. E. Notices for the JOURNAL are not acknowledged by personal letter, but if received prior to the 16th of the month will appear in the issue of the following month. All replies to either “Opportunities” or “Services Available” should be addressed to the key number indicated in each case and forwarded to EMPLOYMENT SERVICE, as above. Replies received by the bureau after the position to which they refer has been filled will not be forwarded, and will be held by the bureau for one month only. Information regarding the notices published is on file in the offices of the member societies of the Federated American Engineering Societies. View full abstract»

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  • Officers of A. I. E. E. 1921–1922

    Page(s): 45
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    Freely Available from IEEE
  • Digest of current industrial news

    Page(s): 46
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    Freely Available from IEEE

Aims & Scope

This Magazine ceased publication in 1923. The current retitled publication is IEEE Spectrum.

Full Aims & Scope