By Topic

American Institute of Electrical Engineers, Part I: Communication and Electronics, Transactions of the

Issue 5 • Date Nov. 1961

Filter Results

Displaying Results 1 - 18 of 18
  • A general description of D-C digital voltmeters

    Publication Year: 1961 , Page(s): 465 - 470
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1961 KB)  

    The widespread use of measurement transducers producing direct-voltage output signals has led to extensive development of analog-to-digital converters, including digital voltmeters. This situation has resulted from the fact that the information output of measurement devices, if handled in reduction processes in other than digital form, progressively deteriorates in accuracy. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Features of an electronic crosspoint PABX

    Publication Year: 1961 , Page(s): 471 - 474
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1250 KB)  

    Thirteen features characterize the experimental 100-line electronic PABX (private automatic branch exchange), developed at Automatic Electric Laboratories, Inc., Northlake, Ill., a subsidiary of General Telephone & Electronics, Inc. Primarily, the development aims were to gain design and operating experience with electronic switching telephone systems and to test trunking to and from a Strowger step-by-step central office. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Centrex service: A new design for customer group telephone service in the modern business community

    Publication Year: 1961 , Page(s): 474 - 482
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (5521 KB)  

    Since the end of World War II, this country, particularly in the larger metropolitan areas, has experienced the greatest business building construction boom in history. This tremendous increase in new construction has, per se, contributed materially to the correspondingly phenomenal expansion in telephone facilities required to satisfy the increasing customer demand throughout the country, a demand which continually calls for newer, better, and speedier telephone service at prices within reasonable reach of existing levels. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Pole-zero techniques applied to voice-frequency telephone lines

    Publication Year: 1961 , Page(s): 482 - 486
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1766 KB)  

    Most textbooks about transmission lines derive differential equations pertaining to physical phenomena and, after suitable solutions are found, immediately define or describe several parameters: (1) the propagation function and its components, the attenuation and phase shift functions; (2) the velocity of propagation; and (3) the characteristic impedance. Although others exist, the characteristics mentioned are of fundamental importance and interest, and hereinafter will be referred to in the collective sense as the basic parameters. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Noise and intermodulation problems in multichannel closed-circuit television systems

    Publication Year: 1961 , Page(s): 486 - 491
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1993 KB)  

    In the past decade there has been a rapid growth in communication facilities designed to transmit television (TV) signals relatively short distances over coaxial cables. These systems handle six or more video signals which amplitude-modulate (AM) r-f (radio-frequency) carriers in the 8- to 220-mc (megacycle) range. The associated audio signals frequency-modulate (FM) r-f sound carriers whose rest frequencies are 4.5 mc away from their associated picture carriers. These systems are used for industrial, educational, and entertainment purposes, and descriptions of many of them have appeared in the literature.1¿3 This paper will discuss two problems that affect the design of any closed-circuit TV system: thermal noise and intermodulation products created by amplifier non-linearity. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transmission network of an electronic crosspoint PABX

    Publication Year: 1961 , Page(s): 491 - 496
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1881 KB)  

    The purpose of this paper is to discuss the transmission network of a private automatic branch exchange (PABX) which is undergoing operational testing at Automatic Electric Laboratories, Inc., in Northlake, Ill. It was designed to use space-division transmission and time-division common control. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Logical control of an electronic crosspoint PABX

    Publication Year: 1961 , Page(s): 496 - 501
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1899 KB)  

    Recently completed, after 15 months' work by members of Automatic Electric Laboratories, Inc., is a new electronic telephone switching system which will accommodate 100 local subscribers and 20 trunks emanating from an electromechanical exchange.1 Ten of the trunks are PBX (private branch exchange) trunks and ten are 2-way dial trunks. Four operator lines have been established, not only as intermediate terminations for the PBX trunks, but also to provide special services for local subscribers. A 6-position meet-me conference facility is reinforced by a progressive or chain conference feature. Provisions have been made for trunk transfer, trunk restriction, night service, and operator intercept on unequipped lines.2 View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Reliable data transmission through noisy media ¿ A systems approach

    Publication Year: 1961 , Page(s): 501 - 504
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1362 KB)  

    Error control techniques are becoming increasingly important in data transmission systems, since they allow reliable communications over media where the interference is high. Transmission errors can be corrected either by adding redundancy bits to the information to generate an error correcting code, or by automatically retransmitting the message when erroneously received. The relative merits of the two techniques are discussed in terms of both error control and systems compatibility. A class of powerful and easily implemented cyclic error detection and correction codes was recently developed which, in combination with automatic retransmission, should give effective error protection. Once the system reliability requirements are realistically gauged, and the characteristics of the channel interference are known, it is possible to determine a cyclic code best suited to that interference, and to determine a message length for the maximum transfer of information. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Large-scale on-line data processing systems

    Publication Year: 1961 , Page(s): 505 - 509
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3052 KB)  

    On-line data processing systems have been developed for industrial and business problems which may be classed as inventory control of products with regional, nation-wide, or even worldwide distribution and demand. The control and reservation of passenger or cargo space in the transportation industry, the handling of deposits and withdrawals in savings banks with many branches, the processing, distributing, and retrieval of information concerning stock transactions and quotations, and the control of inventory for large-scale manufacturing and distributing organizations as well as for government and military organizations are examples of application for which systems of this type are required. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Computer program for preparing wiring diagrams

    Publication Year: 1961 , Page(s): 509 - 513
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1633 KB)  

    The program under discussion prepares chassis wiring diagrams from a list of the chassis terminals to be connected. The diagrams are figurative, representing the existence, but not the exact location, of real wires on the chassis. These diagrams are a two-dimensional form of wiring information and are therefore of more value in maintenance and production than a single- or double-ended wiring list. In particular, the diagrams may be used to record changes, trace signals, and guide wiring shop personnel. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A magnetically regulated D-C to D-C converter power supply

    Publication Year: 1961 , Page(s): 513 - 518
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1742 KB)  

    In situations where a single d-c source only is available or desirable to power electronic equipment requiring a number of different and isolated supply voltages, a so-called d-c to d-c converter1¿3 can be used. A typical example of this situation is found with mobile equipment where space and weight considerations determine the available power source. Communication equipment having buffer batteries to maintain continuous operation, which are unaffected by interruptions of the primary power source, is another example. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A 30-volt 10-ampere regulated power supply using the variable output transistor oscillator with current transformer

    Publication Year: 1961 , Page(s): 518 - 522
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1407 KB)  

    A previous unpublished paper by the author derived the design equations for the transistor saturable current transformer amplifier. In that discussion, sample calculations were made and an amplifier designed. Measured values were compared with those calculated. It is a short step to use the amplifier previously designed in a direct output power supply to provide a constant 30 volts up to 10 amperes. A current limiting circuit was added to the circuit to restrict output current under overload conditions. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Forcing circuitry: Sequential building blocks for logical design

    Publication Year: 1961 , Page(s): 522 - 531
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3055 KB)  

    The performance of an entire computer system is greatly influenced by the elements that are chosen for its sequential logic. For example, the central processing unit of the IBM (International Business Machines Corporation) 704 was organized around the Haven's delay unit chosen for its storage, accumulator, and M-Q registers. As machines having more parallel operation and increasingly complicated controls are developed, a greater percentage of the machine is composed of sequential devices. It thus becomes more important to consider the logical capabilities of the circuits which are chosen. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A silicon-controlled rectifier inverter with improved commutation

    Publication Year: 1961 , Page(s): 531 - 542
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (5766 KB)  

    The announcement of the silicon controlled rectifier1,2 in December 1957 instituted a new era in the field of electric power conversion. Almost immediately, attention was focused on the application of this device in inversion equipment.3 At first, silicon-controlled rectifiers were substituted for thyratrons in existing circuits. However, such direct replacements failed to take full advantage of the better characteristics of the new device. This paper presents a silicon-controlled rectifier inverter circuit which makes use of a new commutation method. Here the small size, short turn-off time, and low forward voltage drop of the silicon-controlled rectifier are advantageously utilized to provide a more flexible inverter with higher performance and smaller size. The circuit was developed in the General Engineering Laboratory of the General Electric Company. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A comparison of computers

    Publication Year: 1961 , Page(s): 542 - 547
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1902 KB)  

    A routine simulating the operation of an analog computer was constructed for use on a digital computer at the Jet Propulsion Laboratory. This code, called DEPI,1 as an abbreviation for ¿differential equations pseudocode interpreter,¿ provides much of the flexibility and ease of operation associated with analog computer operation. A study was made in which the speed, accuracy, and flexibility of the DEPI system were compared with those attributes in a digital differential analyzer, an analog computer, and a digital computer. The vehicle of comparison was a zero-lift, zero-angle-of-attack missile-trajectory problem. The results of this comparison are presented here in tabular and graphical form. Because of variations which exist among commercial models of each type of computer used in the study, the salient features of the particular models are described. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Results of simulation comparison of control computers

    Publication Year: 1961 , Page(s): 547 - 550
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1901 KB)  

    In considering a digital computer for use in a control system, two types of digital computers are generally recognized today: whole word, commonly referred to as general-purpose, and partial word or incremental computers. One or the other may be ideal for a specific application, but, since they differ considerably in basic concept, neither of them can solve all problems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Educating electrical engineers for professional careers

    Publication Year: 1961 , Page(s): 551 - 554
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1539 KB)  

    In any current discussion of engineering education, particularly electrical engineering education, inevitably a conflict arises between those who wish to inject more science and mathematics into curricula and others who insist that engineering colleges should train engineers, not scientists. This paper supports neither side of this controversy but presents the arguments for the following thesis: The present emphasis on science and mathematics in electrical engineering curricula is creating a research-oriented type of undergraduate education that may lead to inadequate preparation for professional careers. Since 80 to 90% of the undergraduates intend to follow professional rather than research or teaching careers, re-evaluation of the goals of undergraduate education is required. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Motivation through challenge

    Publication Year: 1961 , Page(s): 554 - 556
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (976 KB)  

    Every teacher is well aware of the importance of motivation in the performance of his students. It is a matter of common observation that a student of superior ability who loses his desire to learn quickly becomes an academic liability. Achievement seems to be something like the product of natural ability times motivation, integrated over the period of learning. Although the source of motivation is sometimes beyond the instructor's control, on the average it is the teacher himself who must take the responsibility for generating in his students not only the desire to learn but the will to do the work of learning. The thesis of this paper is that a strong intellectual challenge is the most effective means of motivation, and that electrical-engineering education over the past few years has developed in precisely this direction. One such program, based on a new kind of introductory course, is described. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

This Transactions ceased publication in 1963. The current retitled publication is  IEEE Transactions on Communications.

Full Aims & Scope