Showing papers in "Electrical Engineering in 1953"
TL;DR: The International Electrotechnical Commission (IEC) is concerned with the development of international agreement on electrical standards as mentioned in this paper, and it has recently reported on actions taken at its recent meetings in Holland.
Abstract: The international electrotechnical commission is concerned with the development of international agreement on electrical standards. The president of the Commission reports herein on actions taken at the organization's recent meetings in Holland.
774 citations
TL;DR: The AIEE embarked upon a new organizational policy and also instituted a new publication plan for the technical papers during Quarles' term as president as mentioned in this paper, which was followed by a reorganization of the AIEE.
Abstract: At the close of the 1952–53 administrative year, Mr. Quarles takes a look at the Institute's record during his term as president. During this time, the AIEE embarked upon a new organizational policy and also instituted a new publication plan for the technical papers.
267 citations
TL;DR: In this article, the authors present a simple, yet reliable, source of microvolts for measurements in general and for radio receiver sensitivity determinations in particular, which seem to satisfy that need most adequately, were recently developed.
Abstract: The questionable accuracy of radio-frequency microvoltages has been of great concern to the radio field for many years. There is an urgent need for a simple, yet reliable, source of microvolts for measurements in general and for radio receiver sensitivity determinations in particular. Extremely simple devices, which seem to satisfy that need most adequately, were recently developed. They are sources of potential drop obtained across a known resistance through which known currents flow. These devices provide constant voltage sources of accurate microvolts over a range of 1 to 105 and wider, at all frequencies to 300 megacycles and higher. They are adaptable for balanced as well as for unbalanced sources. Their electrical constants are simply determined by using known direct voltages and currents. Basic principles, design features, and applications are discussed.
33 citations
TL;DR: The primary physiologic effects of microwaves appear to be due to the heating and are accompanied by an increase in the flow of blood, however, several undesirable effects were noted in connection with treatment of the eye, the most serious being the formation of cataracts.
Abstract: The primary physiologic effects of microwaves appear to be due to the heating and are accompanied by an increase in the flow of blood. However, several undesirable effects were noted in connection with treatment of the eye, the most serious being the formation of cataracts. Other cautions necessary in the therapeutic application of microwaves are presented.
16 citations
TL;DR: In this paper, a general procedure, using frequency response techniques, is outlined for the synthesis of compensation in systems affected by coulomb friction, which is based on the recognition that a control device has a describing function which reduces gain and introduces phase lag.
Abstract: The presence of coulomb friction in servomechanisms often results in undesirable effects, such as an operating dead-zone, low-frequency wander, and poor dynamic performance for low level signals. Methods of compensation for these adverse effects are discussed and a specific example is presented. Also, a general procedure, using frequency-response techniques, is outlined for the synthesis of compensation in systems affected by coulomb friction. The methods employed are based on the recognition that coulomb friction in a control device has a describing function which reduces gain and introduces phase lag. The describing function is determined by both the amplitude and the frequency of the input signal to the device.
13 citations
TL;DR: In this article, it has been shown that transient stability problems can readily develop if this approach is carried too far, and it has become apparent recently that transient instability problems can be readily developed if the approach is too far.
Abstract: STEADY-STATE OR TRANSIENT STABILITY problems are not significant limitations on most power systems today. However, under some circumstances it is logical to split existing systems and perhaps add reactors to prevent costly increases in interrupting capacity of circuit breakers. It has become apparent recently that transient stability problems can readily develop if this approach is carried too far.
13 citations
TL;DR: In this paper, it was shown that corona is the limiting factor in determining satisfactory voltage stress levels in capacitors where high operating stresses are desirable, and obtainable through the use of high-quality insulation.
Abstract: CORONA OFTEN BECOMES the limiting factor in determining satisfactory voltage stress levels in capacitors where high operating stresses are desirable, and obtainable through the use of high-quality insulation. Recognition of this factor has resulted in extensive investigations1 of the effects on corona of many design and operating variables, and subsequent analysis of test results has revealed certain concepts which explain much of the behavior of corona in thin dielectrics.
13 citations
TL;DR: The formation of an Atomic Industrial Forum, the resignation of Dr. Astin as Director of the National Bureau of Standards, and the latest development in plans for a new Engineering Societies Building are items of current interest to the membership discussed by President Quarles in this report.
Abstract: The formation of an Atomic Industrial Forum, the resignation of Dr. Astin as Director of the National Bureau of Standards, and the latest development in plans for a new Engineering Societies Building are items of current interest to the membership discussed by President Quarles in this report.
11 citations
TL;DR: In this paper, a method of reducing the core flux of a current transformer by supplying the necessary voltage to the secondary circuit is described, and test results are given for ratios down to 20/5 amperes.
Abstract: A method is described of reducing the core flux of a current transformer by supplying the necessary voltage to the secondary circuit For one load current, the flux may be eliminated, giving zero errors, and at other loads the ratio and phase angle are so small as to be difficult to detect in many cases Applied to reasonably good transformers, extremely high accuracies are obtained, with small weight and bulk The scope of low ratio bushing-type transformers is also increased, but the addition of triple-frequency auxiliary flux still further extends the use of the method, and test results are given for ratios down to 20/5 amperes
11 citations
TL;DR: In these days of uncertainty and indecision, when free peoples are struggling to maintain their freedoms, a nation's educational system can be its greatest resource as mentioned in this paper, and the Chancellor of New York University here discusses the future of American education and its relationship to some of the national and international problems we now face.
Abstract: In these days of uncertainty and indecision, when free peoples are struggling to maintain their freedoms, a nation's educational system can be its greatest resource. The Chancellor of New York University here discusses the future of American education and its relationship to some of the national and international problems we now face.
11 citations
TL;DR: In this article, an accurate method has been devised to determine readily system transmission losses for all normal variations which might be encountered in the parallel or looped operation of several interconnected companies.
Abstract: IN ORDER TO account for losses in interconnected system operation, an accurate method has been devised to determine readily system transmission losses for all normal variations which might be encountered in the parallel or looped operation of several interconnected companies.
TL;DR: In this paper, it was found that a critical moisture content of approximately 4 per cent by weight separated two distinctly different phenomena whereby heat is dissipated from buried transmission cables or other heat sources.
Abstract: By experiment it was found, in an idealized soil, that a critical moisture content of approximately 4 per cent by weight separated two distinctly different phenomena whereby heat is dissipated from buried transmission cables or other heat sources. Above this moisture content relatively large quantities of heat per lineal foot can be dissipated by what appears to be a circulation phenomenon. Below this moisture content the soil rapidly dries out, materially decreasing the quantity of heat that can be dissipated. This last phenomenon may be the explanation of the so-called "runaway condition" observed in practice in connection with buried transmission cables.
TL;DR: A detailed description of this new simple pneumoplethysmograph utilizing an electronic transducer is presented, valuable in clinical work as it can record systolic blood pressure at various points on the extremities, volume pulsations of the toe or finger, relative blood flow, potentialBlood flow, peripheral resistance, vasomotor activity, and other vascular phenomena.
Abstract: A detailed description of this new simple pneumoplethysmograph utilizing an electronic transducer is presented. It is valuable in clinical work as it can record systolic blood pressure at various points on the extremities, volume pulsations of the toe or finger, relative blood flow, potential blood flow, peripheral resistance, vasomotor activity, and other vascular phenomena.
TL;DR: In this paper, the flow of electromagnetic energy is traced in a typical, somewhat idealized, d-c generator, using an adaptation of Poynting's vector, after a discussion justifying this procedure.
Abstract: The flow of electromagnetic energy is traced in a typical, somewhat idealized, d-c generator, using an adaptation of Poynting's vector, after a discussion justifying this procedure. Quantitative analysis of the flow within the conductors and in the gap is carried out following the specification of the electromagnetic fields. Qualitative analysis of the flow in intermediate regions and to machine output leads is presented. Extension to other types of machines and to less idealized situations is discussed.
TL;DR: The British system of Establishments for attacking technical problems is described in this article together with some of their methods for solving the problems of radar sets and their accomplishments, however, many problems remain to be solved and this is especially true in the components of the equipment.
Abstract: Although forward strides have been effected in radar sets and their accomplishments, many problems remain to be solved and this is especially true in the components of the equipment. The British system of Establishments for attacking technical problems is described here together with some of their methods.
TL;DR: In this article, Major Armstrong makes such an analysis of Guglielmo Marconi's three great discoveries in the field of radio transmission and reception, and concludes that the attitude toward problems and how he solved them merit study.
Abstract: It is not often that historical records show the name of a man credited with two basic discoveries. When a man has made three, then his attitude toward problems and how he solved them merit study. Major Armstrong makes such an analysis of Guglielmo Marconi's three great discoveries in the field of radio transmission and reception.
TL;DR: In this article, a self-contained switch is proposed to interrupt line-charging currents, transformer-magnetizing currents, and load currents of transmission voltages, which is composed of a modern vertical break air switch combined with a porcelain-clad gas-filled chamber.
Abstract: This new completely self-contained switch interrupts line-charging currents, transformer-magnetizing currents, and load currents of transmission voltages. It is composed of a modern vertical-break air switch combined with a porcelain-clad gas-filled chamber. It is small, lightweight, easily operated, and economical.
TL;DR: In this paper, a method of functionally evaluating insulation systems in 5-horsepower 440-volt 3-phase squirrel-cage motors is presented, and a test procedure is given for a test cycle involving periods of humidification and heat run.
Abstract: This paper gives a method of functionally evaluating insulation systems in 5-horsepower 440-volt 3-phase squirrel-cage motors. By this method it is possible to compare various insulating systems with acceptable standards in terms of the years of expected life at any selected operating temperature. A motor test station is described and a procedure is given for a test cycle involving periods of humidification and heat run. Various data on insulation systems under test are given as an example of what might be expected from this method.
TL;DR: In this article, it was shown that at larger angles of overlap an inherent delay angle, introduced by a-c reactance common to two or more simple rectifiers, reduces the direct voltage and thereby increases the voltage regulation.
Abstract: CONVENTIONAL METHODS of calculating rectifier voltage regulation are valid only if the angle of overlap is less than 360 degrees divided by the number of phases. At larger angles of overlap an inherent delay angle, introduced by a-c reactance common to two or more simple rectifiers, reduces the direct voltage and thereby increases the voltage regulation. This phenomenon has been described in two papers,1, 2 recently presented to the Institute, in which curves and equations for determining voltage regulation of 6-phase rectifiers were given. Two earlier articles5, 4 recognized the phenomenon in 6-phase circuits.
TL;DR: In this article, the authors proposed indirect high-resistance neutral grounding by connecting the primary winding of a distribution transformer between generator neutral and ground, and by loading the secondary of this transformer with a resistance of such magnitude that the resulting primary ground current for a solid ground fault at machine terminals becomes 10 to 20 amperes.
Abstract: A-C GENERATORS in modern power plants usually are operated in unit connection directly on high-voltage bus bars, that is, alternator and transformer form one unit so that the circuit breaker at generator voltage is eliminated. A preferred method of ground protection for such units has been indirect high-resistance neutral grounding by connecting the primary winding of a distribution transformer between generator neutral and ground, and by loading the secondary of this transformer with a resistance of such magnitude that the resulting primary ground current for a solid ground fault at machine terminals becomes 10 to 20 amperes. This grounding method was first suggested1 in this country by L. F. Hunt as a means of minimizing fault damage within generators. The sensitivity of this scheme of protection depends on the lowest permissible pickup current of a relay activated by the current through the resistance. This pickup current indicates the parts of the machine windings which are protected. The straight line in Figure 1 shows that the assumed relay setting would lead to relay operation for faults anywhere between machine terminal (100) and location a, whereas ground faults between the neutral (0) and a would lie in the unprotected or dead zone.
TL;DR: In this paper, it was shown that the temperature distribution along the fuse wire, at the instant of melting, depends upon the fault magnitude and on the dimensions of the fuse cartridge.
Abstract: WHEN FAULT CURRENT FLOWS in a fuse element, the temperature distribution along the fuse wire, at the instant of melting, depends upon the fault magnitude and on the dimensions of the fuse cartridge. If the current is low, and near to minimum fusing current, and the cartridge dimensions are normal, or, if the current is high and the cartridge is very short, the distribution will assume a parabolic form, and melting will occur at the center of the wire. If the current is high and the cartridge dimensions are normal, or, if the current is low and the cartridge is very long, the distribution will have a rectangular form, and most of the wire will melt at the same time. The melting depends on current density and wire parameter.
TL;DR: The EDVAC is a large-scale digital computer utilizing an unconventional language and logical structure to solve complex problems.
Abstract: The EDVAC is a large-scale digital computer utilizing an unconventional language and logical structure to solve complex problems. A discussion of these elements is followed by a description of the units that mechanize these characteristics.
TL;DR: In this paper, some developments in the field of built-up bonded mica products for use as electrical insulation are described with emphasis placed on high-temperature applications, and some of them are discussed in detail.
Abstract: Certain developments in the field of built-up bonded mica products for use as electrical insulation are described with emphasis placed on high-temperature applications.
TL;DR: In this article, a creative environment for the study of energy conversion and utilization subjects was established for the students in the electrical engineering education at the University of Hong Kong, which lost much of its popularity with students to the more glamorous communications and electronics curricula.
Abstract: With the growth of electrical engineering and the introduction of options in engineering education, the electric power field lost much of its popularity with students to the more glamorous communications and electronics curricula. To compensate for this trend, the universities must establish a creative environment for study of energy conversion and utilization subjects.
TL;DR: In this article, the effect of a limiter on a signal is analyzed based on a simple physical concept of the limiter and does not require the use of advanced mathematical techniques.
Abstract: This method for analyzing the effect of a limiter upon a signal is based upon a simple physical concept of the limiter and does not require the use of advanced mathematical techniques. The limiter is treated as a variable-gain device which amplitude modulates the input signal. Two examples demonstrate the new method.
TL;DR: In this paper, the electret effect in high polymer plastics is described and compared to published data on the behavior of wax electrets, which indicate the existence of large ionic polarizations giving rise to an essentially constant external electric field.
Abstract: The electret effect in high polymer plastics is described and compared to published data on the behavior of wax electrets. The results indicate the existence of large ionic polarizations giving rise to an essentially constant external electric field. Some engineering applications of electrets are discussed and limitations presented in terms of current knowledge of electret phenomena.
TL;DR: In this paper, the historical development of computers is discussed and current problems and future structural and functional computer trends are discussed, which will help to free man from burdensome calculations and increase his material wealth while permitting him more time for pursuits not directly concerned with earning a living.
Abstract: This article deals with the historical development of computers. It also discusses current problems and indicates future structural and functional computer trends which will help to free man from burdensome calculations and increase his material wealth while permitting him more time for pursuits not directly concerned with earning a living.
TL;DR: In this article, the authors proposed changes in United States practice and Canada practice for the benefit of engineers of other countries, while the practices in the United States and Canada were presented for the purpose of improving their own practices.
Abstract: Certain changes in United States practice are proposed, while the practices in the United States and Canada are presented for the benefit of engineers of other countries.
TL;DR: In this paper, the authors used data supplied by the Electrical Engineering Departments of 102 schools in the United States to indicate the quantity and quality of the graduates entering the power and electronics fields.
Abstract: This provocative article, based on data supplied by the Electrical Engineering Departments of 102 schools in the United States, indicates the quantity and quality of the graduates entering the power and electronics fields. Both causes and possible remedies for this unfortunate condition are presented here.
TL;DR: In this article, a dielectric strength criterion was proposed for dry-type insulating systems, which is applicable to a large range of materials and readily interpretable in terms of expected life of apparatus.
Abstract: THE METHOD CHOSEN for evaluation of insulation aging should be representative of operating conditions, applicable to a large range of materials, and readily interpretable in terms of expected life of apparatus. A dielectric strength criterion meets these requirements for dry-type insulating systems. In utilizing this criterion the initial strength of each insulation system is determined at the temperature being investigated. Duplicate samples of the insulating systems are then thermally aged at this temperature and periodic, 60-cycle, 1-minute dielectric strength tests are applied at a value of one-half of the initial hot-dielectric strength until failure occurs. Plotting the hours of thermal aging to reduce the dielectric strength to one-half of its initial value against the operating temperature for a range of temperatures gives the thermal aging characteristics for the insulating system.