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A discussion of end devices, and their application to supervisory control systems is presented. The author describes a hypothetical supervisory control application, and discusses system application techniques. Technical merits and/or liabilities associated with each application technique are discussed in conjunction with the associated economics. The paper not only discusses supervisory control systems, but end devices, man/machine interfaces, communication networks, and lightning protection. The paper concludes with the author's impression of what the end user can anticipate from manufacturers of supervisory control systems, end devices, and communication equipment.

Prestressed concrete transmission towers for 400 to 750 kV are now in operation at the extra-high voltage research project. Radio noise tests; lightning effects; structural design of tower; tower configuration; design considerations; foundations; fabrication and shipping; and erection are described.

Cables are designed to have special characteristics which will make them suitable for particular uses or purposes. In the case of telephone cable the purpose is primarily to transmit information at voice and carrier frequency during an expected life of approximately 30 years. To achieve this, certain mechanical and electrical characteristics must be built into the cable. Mechanical characteristics include such characteristics as resistance to environmental factors including heat, cold, wind, lightning, moisture, sunlight, and oxygen, as well as resistance to damage by rodents and insects, and by workmen. Other desirable mechanical characteristics involve factors of convenience of manufacture, installation, and joining.

For some considerable time, experience has been accumulated on the retardation of military aircraft on landing by means of a brake parachute. A patent for such a device, for example, was granted to Captain, now Colonel, Prospero Freri, in Italy in 1930. The first useful applications were towards the end of the Second World War on gliders and fighter aircraft, but systematic use of this type of decelerator on American aircraft began just before 1950. The first postwar British service aircraft fitted with a brake parachute was the Vulcan, followed closely by the Lightning and the Victor. These three aircraft use brake parachutes to reduce the landing run and also to reduce wear and tear on the aircraft brakes and tyres. The Lightning in particular has been the subject of extensive application of the brake parachute.

This review of typical advances in various fields and industries made possible by the practical application of research demonstrates the vital role played by measurements

THIS oscillograph was designed to meet the specialized needs of a group that uses the cathode-ray oscillograph as the principal tool in the study of transients in-lightning-arrester development. The instrument is desirable for many purposes, especially those requiring very high writing speeds in connection with nonrepetitive transients where photographic records must be obtained. Other requirements of primary importance in the design were convenience of operation; accuracy of measurement of current, voltage, and time; accuracy of the timing; and linearity and rectilinearity of the plate pattern.

Underground cables for transmission of power at 33,000 ft. and above have only recently come into use in America, or received much attention here. In connection with such cables suitable terminals are necessary and present an important problem in high-voltage design. A marked tendency is noted toward the oil-filling of cable joints; terminal conditions make this procedure both logical and desirable. Dielectric strength must first be specified, and should exceed that of the cable; flashover should occur without puncture; lightning voltages should be guarded against in the design. Proper d-c. tests are still undetermined for various combinations of solid and liquid dielectrics, and a rigid practise can not yet be established with assurance. At present, high-voltage cable lines are intended for a-c. operation, and safety factors should be determined for that kind of service. High-voltage d-c. operation may come into practise later, and research in d-c. testing should be pushed. Standard ratings of terminals are proposed, corresponding to the accepted standard ratings for other high voltage apparatus. Consistency with other terminal insulation, such as apparatus bushings and line insulators, is desirable. Cable insulation may eventually experience similar standardization. The method of rating single-conductor and three-conductor cables should be harmonized, and both based on operating-line voltage. Four typical designs of high-voltage cable terminals are, described representing a carefully worked out and effective solution of the problem. These are (a) 37,000-volt three-conductor; (b) 50,000-volt single-conductor; (c) 73,000-volt, single-conductor; and (d) 110,000-volt single-conductor.

This paper describes a fast easy method for determining expected surge voltage with the help of traveling-wave theory. The intent is to assist the Design Engineer in deciding what degree of surge protection should be provided and where to locate it.

The Bell Telephone Company of Canada recently conducted a successful field trial of gas-filled protectors on open wire and cable intertoll facilities. The purpose of this trial, as well as extensive preliminary laboratory tests, was to compare the electrical and maintenance characteristics of gas-filled protectors with those of the conventional carbon-block spark-gap protectors. Results are summarized herein.

The extensive range in time duration (from microseconds to seconds) of power line distrubances which might affect the operation of data processing equipment requires monitors with characteristics not generally available. The operating and detection characteristics of two types of monitors specifically developed to monitor these disturbances are described. The first is an oscilloscope-automatic camera monitor called an "analog monitor." The second is a small, two-unit "digital printout monitor." Data obtained from the use of these monitors is also presented.

The object of this paper is to describe a new instrument which will record the time to the second of a phenomenon of any kind that can be made to close an electrical contact. Besides recording whether a phenomenon is starting or stopping, a printed record is made of the day of the week, a.m. or p.m., the hour, minute, and second. The highest number of records put on a sheet by a single one of these instruments so far is thirty. The instrument is capable of recording a movement of all of its pencils or type wheels simultaneously, or the movement of any lesser number. Every record shows the position of every type wheel whether it moves or not. The instrument records only to the nearest second but in case of successive discharges during a single second their relative precedence is noted by giving them successive prints of the same second. In this manner the recorder will split a second into about four parts. The manner of operation will be described later.

Due to their greater economy, gigahertz computers will eventually replace megahertz computers. Circuits and system organizations have been actively explored for the last 3 years, and various devices and circuits have been proposed. This paper attempts to integrate and give perspective, from a system viewpoint, to isolated disclosures, by classifying and contrasting various developments with emphasis on the more promising approaches. The first gigahertz computer will probably be made of tunnel-diode baseband circuitry. For the long range, thin-film cryotrons, with a cost advantage of 100 to 1 over tunnel diodes, show the greatest promise.

Rotating machines supplied directly from utility distribution systems are subjected to various overvoltages. Depending on the power system in question, these overvoltages may or may not be hazardous to machine insulation. The magnitude of the overvoltages, whether of internal or external origin, can be limited by the protective devices commonly used for machine protection. An operator must satisfy himself, however, that the insulation in question has sufficient strength to be protected by these devices. This determination of insulation strength is readily accomplished by means of nondestructive direct high-voltage tests. How these tests are made has been discussed in considerable detail for the bene fit of those contemplating the incorporation of such tests in a preventive maintenance program.

As an example of how information from various sources can be assembled into useful form for the operating engineer, a guide on system grounding techniques is presented. In addition to the initial establishment of grounds, a definite inspection and maintenance procedure which will assure adequate protection of personnel and equipment is recommended.

Communication cables consist of a number of electric conductors insulated from one another and encased in a metal sheath. This encasement is subjected to numerous hazards, such as those caused by electrolysis, crystallization, various kinds of mechanical damage, and lightning burns. Any damage to the sheath which will permit water enter the cable will decrease the effectiveness of the insulation material and thus cause an impairment or an interruption to the service. The entrance of moisture through small openings in the sheath can be materially retarded when the space inside the cable, not occupied by the conductors or insulation, is filled with a gas maintained under controlled conditions. Nitrogen is the gas usually used for this purpose because it is inert and does not combine chemically with the conductors or insulation. In addition the use of the gas provides a method of locating openings in the sheath by means of a pressure gradient, which is a material aid in cable maintenance.

Various types of possible danger from radio installations are considered: shocks to the operator, short-circuit from lightning or from contact with high tension power lines, breakdown from the high tension circuits of the radio transmitter itself, and harmful inductive effects from radio transmitters. In each case, instances are given together with the proper means of avoiding the undesired effect. In this connection, some detailed experiments are described.

THE USE of protector tubes (previously referred to as expulsion protective tubes or “deion” gaps) during the past five years or so as devices for protecting transmission lines and equipment against lightning has gained considerable headway, particularly in the protection of high-voltage transmission lines. A number of applications have been made in the medium voltage transmission field, a few in the low-voltage field, and a number of scattered installations for protection of equipment and cables.

A new and improved system of distribution pole-top construction has been introduced under the name of Thortec. Without the use of an overhead shield wire, it provides lightning protection comparable to fully shielded construction, in addition to high immunity to the effect of lightning strokes terminating on objects adjacent to the line. Thortec is extremely effective in combating aerial contamination and has proved its ability to maintain continuity of service in areas heretofore subject to high outage frequency. This new system is free from interruptions caused by accidental contact of birds or climbing animals. Symmetrical, compact design lends attractive appearance to Thortec lines and permits their use, as opposed to more costly underground construction, in many areas where aesthetic values are highly stressed.

Lighting disaster is one of the common natural disasters. Railway signal system is an important guarantee for the safety of railway transportation. There are no standards to assess the impact of lighting disaster on railway signaling system now. The principles of lighting transmission are analyzed firstly in this paper. The impact degree of lightning disaster was studied according to the lighting principles. The emphasis on lighting is the effect of direct lighting and induction lighting. Then the risk component assessment models have been established on basis of the analysis of lightning effects. Finally the risk assessment model of lighting on signaling system is given.

Turbo Lightning is an effective and easy to use package that monitors what the user types, and beeps whenever it thinks a word has been misspelled. It works best if you have a hard disk and 256K or more Ram memory. Users can draw on pull‐down lists of “sound‐alike words” and a thesaurus to replace incorrect or misspelled words automatically.

If your company is struck by lightning, you don't want your company to join the scrap-heap. This is why every firm should have its own recovery strategy in case the computer goes out of action.

Classroom use of the Personalized System of Instruction (PSI) was investigated by sending questionnaires to three groups, early (before 1975) users of PSI, recent (after 1975) users, and current chairpersons of psychology departments. Data from all three sources suggest that fewer PSI courses are being taught, and that many depart substantially from the original PSI format.

A computer is nothing more than an organized bureaucratic structure that allows one to perform a large number of very simple acts by the issuance of a few simple commands. It has the disadvantage of being a machine and, at the present time, being incapable of interpretive behavior. Such machines can only follow orders blindly. On the other hand, the computer is capable of performing simple tasks at lightning speed. Learning how to take advantage of this ability is no more difficult than learning to reduce a Colle's fracture. Buy a book, obtain some "clinical material" (a computer), and start experimenting. Learn from your mistakes; it only takes time and interest--not genius.

ON THIS and the following 2 pages appear all remaining discussions submitted for publication, and approved by the technical committees, on papers presented at the 1937 AIEE winter convention, New York, N. Y., January 25–29. Discussions of papers presented at the sessions on general power applications, vibration and balance, communication and research, power transmission, education, power generation and electrical machinery, instruments and measurements, insulation co-ordination, and lightning protective equipment at the 1937 AIEE summer convention, Milwaukee, Wis., June 21–25, now are being reviewed by the technical committees, and will appear in ELECTRICAL ENGINEERING as they are released for publication.

Analysis of pinhole phenomena reveals possibility that high voltage may develop across cable insulation although the underground secondary system has no direct connection to overhead lines. Experience has shown that lightning arresters across the system bus will materially reduce cable failures. They will also limit the transient voltages caused by switching and similar surges.

UNDER present wartime conditions the need for conserving critical materials has been impressed upon the electrical industry with emphasis. It is for this reason that the lightning arrester subcommittee of the protective devices committee undertook a review of lightning protective devices and practices and their application to uncover and present any worth-while savings which it seems possible, practical, and reasonable to obtain. Within the short time since this project became active, it has not been possible to obtain committee agreement on all the various considerations involved. Therefore, rather than withhold from the industry the value of constructive study and suggestions already available, this paper is being presented without the sponsorship or any commitment by the lightning arrester subcommittee. It is hoped that its presentation and the discussions it will initiate will be helpful to the committee in continuing its work on this project to a conclusion. It is the purpose of the paper to give some results of a study on this problem up to the time the paper was prepared.

The paper describes the electrical installation in the Royal Festival Hall and illustrates some of the problems encountered in its design. Lightning protection, the power installations, and the primary, secondary and stage lighting are described, special attention being given to the development of the dimming arrangements for coldcathode lighting. The description of the sound amplification system includes arrangements for hearing-aids, simultaneous interpretation, and an unorthodox type of interval signal. Other features of the installation are the provisions made for B.B.C. sound and television broadcasts, stage signalling, cueing systems and internal telephones.

A change in procedure in which all interested parties have an equal opportunity to propose changes to ASA C62. This will result in one American Standard on Lighting Arresters instead of two or more separate standards that quite∗∗∗ often conflict in overlapping areas.

In the papers of sessions 8a and 8b, certain technical terms are used which may not be familiar to all readers. For this reason, we are reproducing here, with M. A. Uman’s consent, a few paragraphs of pages 87, 88, 98 and 99 of his book “Lightning” (New York, 1969)

This chapter explores the use of helicopters in building and assembly work in the USSR. The Mi-IOK helicopter-crane does not have the shortcomings of transport helicopters. Below the nose part of the fuselage, a supplementary cabin has been provided for a pilot-operator from where the assembly can be actively carried out. An important positive result of the use of the Mi-IOK helicopter-crane for construction assembly work has been the experience already accumulated, and the advantage of this machine over transport helicopters has been established. Such works as the installation of lightning rods during the repair of the roof of a foundry, assembly, and dismantling of scaffolds, and cranes at the chimney stacks of hydroelectric stations, assembly of girders during the reconstruction of an automobile factory, the assembly of a four-span bridge 120 m long for foot-passage over a ravine in a park, the dismantling of a radio tower in Moscow, and other works were effectively carried out by means of a Mi-IOK helicopter with important economies compared to traditional methods.

A portable EMP surge arrestor test set can assure the EMP protection level at the pin level on hardened systems. EMP protection devices are susceptible to degradation caused by lightning and man-made EMI transients. Devices such as Zeners, MOV's, Gas Tubes and Filters are benign passive devices that protect electronic systems from EMP transients at the pin level. Degradation of these devices are normally not detectable by system operation. A portable EMP test set was developed that generates a transient on a protected pin and measures degradation of EMP protection devices before catastrophic failure.

A set of interim inspection guidelines is provided to assess the safety of a residential PV system until more formal documentation is available from code-generating groups. Included are definitions, source electrical characteristics, grounding, isolation, lightning protection, overcurrent protection, disconnect means, wiring methods, and structural guidelines. Suggested forms are included for system component identification, as well as a discussion of equivalent system grounding protection. (LEW)

This report presents a review of lightning warning techniques with emphasis on explosive facilities and operations. An explanation of how each technique is used to detect the presence of conditions that can lead to these discharges, with the advantages and limitations of these techniques is given. In addition, an attempt is made to show how the lightning detection hardware can be incorporated into a facility's Hazardous Weather Plan.

This paper gives an overview of the various types of devices most commonly used for telecommunications protection. Gas discharge and solid state devices are discussed insofar as their application to signal line protection is concerned. Their failure mechanisms, some of their shortcomings and advantages as well as the application of combinations of both types of devices is also covered. Good bonding and grounding is extremely important to the proper operation of any protection system. A discussion of the effects of improper bonding and the resultant problems is also presented.

Publisher Summary This chapter focuses on the protection of radio equipment. All radio equipment should be provided with protective circuits. There are two main reasons for providing protection, namely, to prevent a component or equipment assembly reaching a temperature that might result in fire and to minimize the hazards to staff in the event of an unsafe condition developing. Radio equipment that would require maintenance work upon it should have approved means of disconnecting it from all unearthed conductors of its supply circuit. Care must be taken in the design of the control circuit or mechanism that power cannot be restored while work is in progress. To provide adequate protection for staff, equipment, and plant against lightning, it is necessary to install facilities by which a discharge is not required to pass through a path of high impedance. The station property should also be enclosed by a fence of proper height and construction that would prevent access to the property by unauthorized persons and grazing animals.

In this paper I am going to try to draw a lightning sketch of the structure of the design process; to indicate where past and present computer aids fit within that structure; and then to offer some personal and rather fragmentary ideas as to where computer-aided design, and in particular its use of graphics, might go in the future.

This report describes a microprocessor-controlled data acquisition module which is battery powered and communicates with a master computer via a fiber optic link. This allows the module to be used in hazardous areas with complete electrical isolation. The module allows digital inputs, digital outputs, and analog to digital conversion with analog input multiplexing. A complete description is given along with diagrams, schematics, and program listings.

A two-chip hybrid integrated trunk and subscriber line interface has been fabricated for voice and data applications. This paper will discuss features including a programmable battery feed with lightning protection, battery-reversal signaling, 2-4 wire conversion, loop closure detection and power down capability.

A performance/failure analysis was conducted on three acoustic arrays recovered from a depth of 3300 ft at a naval tracking range off St. Croix in the Virgin Islands. The analysis included bench tests of electronic components and examination of connectors, cables, seals, and housings with electron microscopes, X-ray diffraction, and optical microscopes to determine the effectiveness of design features and materials. One array had been submerged for about 10 years, the others for 6 years. Cables with polyethylene jackets performed satisfactorily whereas cables with polyurethane jackets exhibited leaks and visible circumferential cracks approximately 1/4 in. long. Of 42 double O-rings examined, 8 of the first O-rings leaked; half of these were on one array. The second O-ring on all seals was effective. Arcing, apparently due to lightning, produced a low resistance in one of the Morrison connector seals by creating a carbon path of charred teflon. Certain packing seal glands and backup washers in the Morrison seals of one array sustained permanent deformation because of improper assembly.

The number of telecom switching offices in the Swedish network is about 7000 and among those, roughly 90% have 2000 lines or less. When converting the telecom equipment from electromechanical to SPC technique, the number of minor switching exchange offices will increase. This paper describes two power supply systems introduced by the Swedish telecom administration as standards for minor telecom installations. When developing these systems, the operation- and maintenance performance and personal safety have been taken into special consideration. These power supply systems will frequently be placed where disturbances such as lightning and other transient voltages occur. Therefore the system design to prevent system failures caused by such disturbances is discussed. It is also discussed how the power supply systems are designed to obtain a nearly equal availibility to the telecom network for subscribers connected to an RSS and to a central switching office. The principles for the described two systems are intended to be used for other telecom systems as well, e.g at fiber optic transmission systems.

A new compact lightning arrestor can be incorporated into a connector housing to protect missile, aircraft and ground systems from lightning energy that can sometimes be transmitted to sensitive components on wires that pass into component compartments. This energy can cause component burnout, ignition of explosives, and circuit malfunctions. By properly incorporating the lightning arrestor-connector, these effects can be minimized or eliminated. The lightning arrestor-connector concept has been theoretically studied and prototype devices have been tested extensively at Sandia Laboratories. The design and development of the device is described along with data demonstrating the device behavior under simulated lightning tests.

What is reading? Where does it start? How can it be done well? With these questions you can make a fortune, wreck a school system or get elected to the board of education. Most people who try to think about reading at all conjure up these little black wriggles on a page and then mutter something about “meaning.” If this is all it is, very few of us would ever learn anything. For reading is older than printing or writing or even language itself. Reading begins with wonder at the world about us. It starts with the recognition of repeated events like thunder, lightning and rain. It starts with the seasons and the growth of things. It starts with an ache that vanished with food or water. It occurs when time is discovered. Reading begins with the management of signs of things. It begins when the mother, holding the child’s hand says that a day is “beautiful” or “cold” or that the wind is “soft.” Reading is “signs and portents,” the flight of birds, the changing moon, the “changeless” sun and the “fixed” stars that move through the night. Reading is the practical management of the world about us. It was this for the man at the cave’s mouth. It is this for us at the desk, the bench or control panel.

A set of three-component long-period instrumentation was added to each subarray of the Montana LASA. The instrumentation, which provides analog signals to the existing data handling and telemetry system of the LASA, consists of three LP seismometers housed in an underground concrete vault and a three- channel, solid-state parametric amplifier located in the Central Telemetry Housing at each subarray. Equipment for interconnection of the instrumentation, lightning protection, and remote adjustments to the seismometers was installed. During the installation, each set of instrumentation was calibrated. This report briefly describes the instrumentation, the installation, and calibration procedures, and the problems encountered during the installation of the LASA LP system.