The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The evolution of electronic components in the computer field, especially increasing density and continuous reduction of the cost of processing and memorization integrated circuits, affects directly the design and development of equipments. The highest concentration of functions involves an increase in the specific power to be dissipated. This has to be taken into account when selecting the type of...
The Swedish Telecommunications Administration - known in Sweden as Televerket - has one of the oldest telephone networks in the world. Advanced product development has enabled very high reliability values to be attained. It has therefore been possible to maintain costs and rates' at a low level. Changeover to digital technique will take place at an accelerated pace by replacement of older equipment...
Lead-acid stationary cells of three types, all with Pb-Ca alloy grids, have been float charged in strings of four or five cells for nearly two years. Individual cell potential differences have been measured during floating at 2.2 V/ cell, during equalisation at 2.35 to 2.4 V, and during periods on open circuit. The potential difference across a cell has been taken as an indicator of its health, following...
Structural foam plastic chassis for the power supplies in the Bell System's DIMENSION?? PBX s??ves over $900,000 each year. This radical design approach saves approximately $60 per power supply because the chassis parts cost less to manufacture, are accurate thus eliminating many assembly problems, integrate details that were previously separate parts, and require no additional finishing for appearance...
Sixty percent of telephone communication equipment power is consumed by the line circuits, 20% by the power supplies and 20% by the common control circuits. In general, line-circuit dissipation is decreasing as more Large Scale Integration (LSI) is introduced, due to special power saving circuits. Powering down under microprocessor control, derating of power devices and use of VMOS will reduce power...
This paper deals with the specifications, characteristics, functions, and examples of applications of the Electronic Universal Load developed for use in the developement of power supply units, their testing and income inspection. The function of controlling load current by entering a BCD code permits, among other functions, automatic testing through connection to a computer. This paper gives a detailed...
Booster DC to DC converters operating with 20 kHz conversion frequency perform rapid regulation that make them very well suited to use as active filters for attenuation of low frequency noise. Booster converters with such filtering qualities are beeing used in a new series of 48 V DC power plants. The noise on the output is kept well below the limits that are specified in the CCITT-recommendations.
System design methods of primary power supply systems using a wind turbine are given at first, compared with various primary power supply systems. Then, a design method for spoiler flaps in the Darrieus wind turbine is given. Last, the tested power supply system, using a wind turbine and a diesel generator, is introduced.
CIT-ALCATEL Series SPC 2700 is a twin tube coaxial cable telecommunications system that can support 2700 two-way vf channels or equivalent signals e.g. broadcast TV, up to 12 Mhz wide plus a digital bit stream up to 8448 kbit/S, over a range up to 2500 km (1500mi) between main stations. The repeaters are powered in a series loop with one remote power supply at each end of a power span. This paper...
Changing technology in the design of new computer power supplies has prompted a reexamination of how electrical power is distributed in a computer center. Proper electrical isolation between computer loads is becoming more important in total center design. This paper is a discussion of the electrical characteristics of a total computer power distribution system. Current harmonics generated by newer...
This paper will analyse the power requirements of a general computer system as well as a particular Univac product related to distributed communications processing. Some general criteria for power levels and quality will therefore be developed. Utility requirements and governmental codes (UL, CSA, IEC, VDE, etc.) will be discussed. To provide the power level density and quality required by present...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.