By Topic

Telephone Energy conference, 1978. INTELEC 78. International

Date 25-27 Oct. 1978

Filter Results

Displaying Results 1 - 25 of 67
  • Intelec International Telephone Energy Conference

    Page(s): i - x
    Save to Project icon | Request Permissions | PDF file iconPDF (402 KB)  
    Freely Available from IEEE
  • Author index

    Page(s): 0_2
    Save to Project icon | Request Permissions | PDF file iconPDF (42 KB)  
    Freely Available from IEEE
  • Power Supply for Telecommunications Systems in the Federal Republik Germany

    Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (785 KB)  

    In the past the progressive development of telecommunications systems has influenced the power supply which has become of great importance today. The planning and realization of the power supply depends on the requirements of the telecommunications equipment and operation. In the Federal Republik of Germany the main point is the central no-break 60 V dc power supply. At modern electronic telecommunications systems it will be completed by dedicated power supplies. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The State of the Art of Telecommunications Power Plants in Japan

    Page(s): 6 - 10
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (382 KB)  

    Various power supply systems for NTT gigantic communication network which involves the world second largest number of telephone sets are described. As for the standard telecommunications power supply in Japan, -48 volts DC is used for switching systems, while -21 volts DC for carrier and radio communication systems and 200 volts AC for data communication systems. However, they are gradually forced to change their supply patterns into lower voltages by the recent transistorization of the communication systems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • State of the Art of Telecommunications Power in the UK

    Page(s): 11 - 17
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1336 KB)  

    Telecommunications equipment in the UK is supplied from a central, standard and modular power plant. Reliability and security is therefore regarded as of prime importance. The paper describes the current approach to modular plant both in the AC and IE fields. Flexibility in planning sad installation is achieved, capital costs are minimised and maintenance charges are reduced. The impact of electronic switching systems and the transition to digital techniques is reviewed, as is the need for energy conservation and future alternative power sources. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Full text access may be available. Click article title to sign in or learn about subscription options.
  • Power Apparatus in the U. S. Telephone Industry

    Page(s): 24 - 29
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (930 KB)  

    A survey of power systems and apparatus now used in U. S. telephone systems, both Bell and non-Bell, Operating features of large dc plants are reviewed and differences between Bell and non- Bell practices are noted. The characteristics of some typical rectifiers and power supplies are listed. Dc to dc converters in general use are compared with 20 kHz designs recently introduced. The history of ringing generators, single frequency and multi-frequency is outlined, and the introduction of solid-state ringing plants noted. A recently introduced power plant which uses a 140 volt battery for reserve power is listed as a significant development. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Power Equipments General Design in the French Telecommunications Network

    Page(s): 30 - 37
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (663 KB)  

    The French telephone system, like in many other countries, is currently in a state of considerable technical development, mainly owing to the introduction of new electronic telecommunication technology. As a result, the exclusive use of semiconductor components has led to the creation of new power units and in particular a centralized power source of an original design, which, in combination with distribution and conversion equipment, can be adapted to the various types of user conditions. This paper firstly describes and analyses the centralized power source and then tackles the problem of the introduction of new conversion techniques and demonstrates how these can be used to produce and altogether new design of power supply. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Full text access may be available. Click article title to sign in or learn about subscription options.
  • System Consideration of Triports

    Page(s): 46 - 49
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (282 KB)  

    The general characteristics of a new power processing circuit called the Triport/sup 1/ are described. The Triport is classified into ac and dc types and its relation to other power processing circuits is established. System arrangements of dc and ac Triports are outlined and comparisons drawn with conventional systems. Finally, some brief comments on discrete Triports are given. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Ac Triport - a New Uninterruptible Ac Power Supply

    Page(s): 50 - 58
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (947 KB)  

    A single-phase, 5.6 kVA ac triport has been developed to serve as an uninterruptible power supply (UPS) for use with critical ac loads. The triport's unique feature is its parallel processing of commercial ac line power and of power derived from a central office battery through a continuously operating inverter. The triport is more efficient, more reliable, and less costly than the traditional serial rectifier-inverter UPS . View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A 15 kVA, three-phase triport is - a new approach to UPS

    Page(s): 59 - 65
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (475 KB)  

    A 15 kVA, three-phase triport is being developed for minicomputer applications requiring three-phase- protected ac power where the source of standby power is a 48 volt battery. The chief advantage of this approach over a conventional UPS is much higher overall efficiency under normal operating conditions when commercial ac is available. An efficiency of 90 percent is achieved under conditions of nominal inputs and balanced, full load outputs. Three-phase commercial ac is processed in parallel with the outputs of three square wave inverters through three ferroresonant transformers. The basic configuration of the three-phase triport is presented and the various control concepts employed to regulate the magnitude and phase of the output voltages under steady state and transient conditions are discussed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • High Frequency Dc Triport , an Uninterruptable Power System

    Page(s): 66 - 70
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (462 KB)  

    The High Frequency (HF) DC Triport is a new power supply concept intended for applications requiring uninterruptible regulated DC energy. The HF DC Triport conditions and transmits energy to a load from two independent energy sources, the commercial AC line and a battery. The HF DC Triport is an alternative power supply arrangement to a conventional rectifier-battery system. The advantages of this new concept are: 1. Significant energy savings can be achieved when powering resistive loads, since the load voltage level is independent of the battery terminal voltage. 2. Stabilized output voltage over wide variations in the AC line and battery voltage. Simple, more efficient, and economical conditioning techniques can be used to convert the output energy to logic voltage levels. 3. Inherent energy carry-over characteristics for several cycles without a battery. 4. Low inrush current during initial start-up typically less than six times full load current rating. The flow of energy is controlled by a power switch which has a dual role as an ac and dc switching regulator. The switching rate is independent of the line frequency and is usually selected above the audible frequencies. The system exhibits first-order dynamics and provides hitless transfers between the ac and dc sources. This paper provides an analysis of the HF DC Triport. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Stirling-Cycle Thermomechanical Power Sources for Remote or Inaccessible Communications Sites

    Page(s): 71 - 78
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1410 KB)  

    The paper deals with primary power sources for remote or inaccessible installations, requiring continuous power of tens or hundreds of watts electrical. It is shown that the relatively high conversion efficiency from heat to electricity which is provided by the Stirling-cycle TMG can reduce the weight of fuel required at the site to about a quarter of the weight of equivalent primary batteries, with resultant operating economies. Two installations are in service in the field, and operating experience is being accumulated. The TMG can also be used with radioisotope heat sources, to provide power unattended for many years, as may, for example, be required by undersea repeaters. Again the relatively high efficiency of the TMG offers advantages of economy over the radioisotope thermoelectric generators used hitherto in undersea applications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Full text access may be available. Click article title to sign in or learn about subscription options.
  • British Post Office Standard Packaged Standby Generators

    Page(s): 85 - 91
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1845 KB)  

    Since 1960 the British Post Office has been installing standby a.c. generator sets in all but the smallest rural exchanges. As part of this program a series of packaged engine-alternator sets, complete with mechanical accessories and tanks for fuel, lubricating oil and water, have been developed. About one third of our present 3000 installed engine-sets are of this packaged type. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Full text access may be available. Click article title to sign in or learn about subscription options.
  • Ac Reserve Energy Systems - Performance During Blackouts

    Page(s): 98 - 103
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (439 KB)  

    A study of 314 AC reserve power plants in Bell System offices involved in 5 major blackouts in 1977-1978, revealed only 2 plant failures resulting in loss of telephone service for a 0.6% failure rate. There were, however, a total of 51 plants experiencing troubles which required operator action to correct. The proliferation of telecommunications equipment in unattended locations with an increasing dependency on AC power, will require a higher order of reliability from the AC reserve energy systems. Data shows rigorous design and performance standards result in improved operation during power failures. Also indicated is the need for more thorough routine exercising to insure the system is capable of operating without assistance for extended periods of time. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Photovoltaic Power for Telecommunications

    Page(s): 104 - 109
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (594 KB)  

    First Page of the Article
    View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Solar Electrical Systems for Communication

    Page(s): 110 - 113
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (258 KB)  

    Two important factors in the future development of modern society are telecommunications and energy. The availability of these two will determine the rate of development of a country. The current and future communication systems depend on cables, fiber optics, microwaves, satellites, etc., but their common factor is the need of electrical energy. This paper deals with the use of solar electrical systems for telecommunication systems. First, various telecommunication devices and systems are analyzed and their energy needs are studied. Later various solar electrical systems are described and proper selection of solar cell arrays and storage systems is performed. The approach to the use of controlled or uncontrolled charging cycles is demonstrated. Economical aspects for decision making are stressed. The use of solar electrical systems is strongly depending upon climathological and radiation levels data. New and cheap radiation acquiring devices are described. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • System Design and Economic Analysis of a Solar Photovoltiac Power Supply

    Page(s): 114 - 120
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (596 KB)  

    Much has been written and continues to be on alternative energy sources in our soon to be energy-short world. One of the alternatives being 'kicked' around in this respect, is photovoltiac power generation using silicon solar cells. With all the seeming euphoric, treatment that these and other 'new energy sources' receive in the press and elsewhere, it is considered apposite at this time to review the economics of the situation in regard of photovoltiac's, and attempt an analysis of the tradeoff's between power level, service life, and current state-of-the-art costs, for a power supply giving up to 2.5KW of power, with comparable reliability to wired supplies. This will hopefully highlight the continuing necessity for emphasis on the reduction of production costs, and increase of conversion efficiency, of these potentially effective devices in power supplies for telecommunications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Regulation and Control of Solar Array Power a Minimum Power Dissipation Approach

    Page(s): 121 - 127
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (782 KB)  

    Two approaches to a full-shunt regulator for regulation and control of solar array output power are described in this paper. The first approach, Linear-Partial-Shunt regulation, reduces the power dissipated in the shunt regulator to less than one shunt of the power dissipated in a fullshunt regulator. The second approach, Linear-Sequential-Partial-Shunt regulation, reduces the power dissipation to less than one-sixth of that dissipated in a fullshunt regulator. The approaches discussed in this paper are simple and cost-effective, and can be easily implemented in any size solar array power system. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transductors - Have They A-Future?

    Page(s): 128 - 134
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (522 KB)  

    Introduction of new technologies has frequently led to the downfall and even disappearance of earlier technologies, particularly when the new technology has gained widespread acceptance and approval, as is the case with Thyristors. Following an initial decline, however, use of Transductors in place of Thyristors for telecommunications charger control is continuing and, in some areas, expanding. Transductors ("Magnetic Amplifiers" or "Saturable Reactors") have thus gone against the normal trends in surviving so far. This paper sets out to explore the reasons behind this apparent anomaly, to give comparisons between available power control systems and to assess the future prospects for Transductors. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Current Trends in Pbx Power Supplies

    Page(s): 135 - 139
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (313 KB)  

    The PBX market in the past few years has been a dynamic one in regards to the introduction of new products having new technology and is expected to continue in the future. This will have a major influence on the power supply designs. This paper will discuss in a general way the trends taking place today in power supply design to meet the changing PBX requirements and the trends in design which are resulting from advanced technologies in the power supply field. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Switched Mode Power Supply for the Pulse Epabx

    Page(s): 140 - 143
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (219 KB)  

    The Pulse EPABX was introduced by Northern Telecom about six years ago, and since then 13,000 have been sold all over the world. The utilization of the Switched Mode Power Supply technology resulted in the reduction of power consumption through improved efficiency. At the same time, the volume and weight of the power system was reduced by half; thus a substantial cost reduction in labour and material was achieved. This paper describes the new integrated power shelf for the Pulse EPABX. View full abstract»

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