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Electrical Engineers, Proceedings of the Institution of

Issue 6 • Date June 1968

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Displaying Results 1 - 25 of 26
  • Some possibilities and limitations of graded dielectric loading. As a means of reducing loss in coaxial cables

    Publication Year: 1968, Page(s):759 - 761
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (333 KB)

    Barlow has suggested that the attenuation coefficient of a coaxial cable might be reduced by a suitable dielectric loading. This suggestion is studied for the case of a dielectric whose permittivity is a linear function of radius. It is found that a decrease in attenuation is possible if the ratio of the outer conductor radius to the wavelength is large enough, and if the permittivity increases wi... View full abstract»

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  • Master circuit matrix

    Publication Year: 1968, Page(s):762 - 770
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (865 KB)

    The setting up of a master circuit matrix, whereby all possible circuits of any given graph or network with the same, or a smaller, number of nodes can be obtained as a simple modification of the former, is discussed. With the help of such a master matrix, it is also possible to obtain accurately the number of all possible circuits in the given graph, without actually generating them. Besides the ... View full abstract»

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  • Wave polarisation and its influence on the power available from a radio signal propagated through the ionosphere. Part 1

    Publication Year: 1968, Page(s):771 - 776
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (788 KB)

    Expressions are derived for the relative amounts of power in the ordinary and extraordinary waves excited by an h.f. radio wave at its point of entry into the ionosphere and for the power in the downcoming components of signal, polarised in the horizontal and normal directions, at a distant receiving point. Sample calculations are presented for single-hop propagation over a path between Lerwick (S... View full abstract»

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  • Wave polarisation and its influence on the power available from a radio signal propagated through the ionosphere. Part 2

    Publication Year: 1968, Page(s):777 - 781
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (556 KB)

    The fractions of power available from linearly polarised receiving aerials responding to the horizontally polarised or normally polarised components of downcoming single-hop skywaves are examined for a number of sample paths. These include long and short circuits in different directions at selected midpoints taken as representative of propagation in various regions of the world. Calculations are p... View full abstract»

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  • Propagation measurements beyond line of sight during thunderstorms

    Publication Year: 1968, Page(s):782 - 786
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (515 KB)

    Field-strength recordings on beyond-line-of-sight paths show distinct enhancement during thunderstorm activity. Measurements at 92, 1100 and 3500MHz were carried out during thunderstorm conditions. The increase of field strength at the higher frequency can sometimes be more than 40dB, but it depends on frequency and scattering angle. The increase in field strength is caused by a diverging downdrau... View full abstract»

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  • Generator for the reciprocals of binary numbers

    Publication Year: 1968, Page(s):787 - 789
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (242 KB)

    A quantity which may easily be measured by digital instruments is sometimes the reciprocal of that quantity which it is desired to measure. A serial method is presented by which a number available in binary code can be converted to its reciprocal. The method is one of approximation using linear sections, and it is illustrated by outlining the design of a 2-section system. View full abstract»

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  • Procedure for minimising the number of crossings in a network

    Publication Year: 1968
    IEEE is not the copyright holder of this material | PDF file iconPDF (90 KB)
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  • Thyristor-assisted commutation in electrical machines

    Publication Year: 1968, Page(s):791 - 801
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1592 KB)

    The paper describes how a small number of thyristors can be used to overcome the physical limitations on d.c.-machine output that are due to commutation. The principle on which the proposed scheme is based is a division of the switching action of a conventional commutator into two parts, an entirely off-load switching by a sliding contact, and a complementary and synchronised on-load switching by ... View full abstract»

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  • Frequency-dependent dynamic, representation of induction-motor loads

    Publication Year: 1968, Page(s):802 - 812
    Cited by:  Papers (6)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1231 KB)

    For comprehensive transient and dynamic stability studies, induction-motor loads have usually been represented by fixed shunt impedances at system nominal frequency. A method is proposed here which allows single induction motors or groups of induction motors to be considered as frequency-dependent and dynamic. If the necessary parameters of the motors are known and if computation effort is not a p... View full abstract»

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  • Eddy-current effects in solid, unslotted iron rotors

    Publication Year: 1968, Page(s):813 - 820
    Cited by:  Papers (5)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1045 KB)

    A turboalternator, when undergoing speed oscillations or when running out of synchronism, experiences damping torques caused by eddy currents set up in the solid iron of the rotor. Previous attempts at estimating these torques have inadequately represented the effects of nonlinearities in the iron, and of return paths for the eddy currents at the ends of the rotor. An analysis is made in this pape... View full abstract»

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  • Effects of slots on eddy currents in solid iron rotors

    Publication Year: 1968, Page(s):821 - 827
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (895 KB)

    The presence of slots in the solid rotors of asynchronously running turboalternators is shown to have a significant influence on the eddy-current distribution in the rotor. The theory presented in a previous paper is extended to cover the effects of the rotor slots, and agreement with torque values observed with a model machine and with a large turboalternator is obtained. The theoretical results ... View full abstract»

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  • Characteristics of a synchronous motor with current-compounded self excitation

    Publication Year: 1968, Page(s):828 - 833
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (770 KB)

    It is common practice with synchronous motors to use some form of excitation control to ensure either constant power factor or constant reactive power at all normal loads. The use of a static current-compounded self-excitation circuit for this purpose is explained in the paper. Measurements showing the accuracy of control and the stability limit during steady-state operation are presented, and the... View full abstract»

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  • D.C. machine as a relaxation oscillator and as a switch

    Publication Year: 1968, Page(s):834 - 841
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (900 KB)

    The use of a d.c. machine as a low-frequency relaxation oscillator is described. The basic machine is a conventional shunt-excited generator to which has been added an inductor connected across brushes in electrical space quadrature with those required for shunt excitation. By adjustment of the inductor and field-winding circuit resistances, the polarity of the terminal voltage can be made to chan... View full abstract»

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  • Ferroresonant servomotor

    Publication Year: 1968, Page(s):842 - 846
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (572 KB)

    The operating principle of the ferroresonant servomotor is described. It is shown that this new actuator for automatic systems is also an amplifier which can be controlled directly by transducers with low-power d.c. signals (photodiodes etc.), so that amplifiers and d.c.-a.c. convertors are eliminated. A comparison is made with the amplifier servomotor, described in a previous paper, showing that ... View full abstract»

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  • Generalised operating characteristics of e.h.v. transmission lines

    Publication Year: 1968, Page(s):847 - 854
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (882 KB)

    Adopting the representative average values of inductive reactance and susceptance of e.h.v. lines, the common power-circle diagrams have been generalised so that they become applicable to each and every case of e.h.v. lines having up to four conductors per phase. With the help of these generalised power-circle diagrams, it is possible to assess and predict very closely the operating characteristic... View full abstract»

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  • Discussion on 'Interlocking in large electricity-supply substations - a fundamental approach'

    Publication Year: 1968, Page(s):854 - 855
    IEEE is not the copyright holder of this material | PDF file iconPDF (237 KB)
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  • Single-unit p.a.m. induction frequency convertors

    Publication Year: 1968, Page(s):856 - 857
    IEEE is not the copyright holder of this material | PDF file iconPDF (309 KB)
    Freely Available from IEEE
  • Discussion on "Modern transmission-line maintenance"

    Publication Year: 1968, Page(s):858 - 862
    IEEE is not the copyright holder of this material | PDF file iconPDF (816 KB)
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  • Corrigendum: Aluminium windings for hydroelectric generators: a critical analysis

    Publication Year: 1968
    IEEE is not the copyright holder of this material | PDF file iconPDF (127 KB)
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  • Multimodal and transitional behaviour in second-order nonlinear systems

    Publication Year: 1968, Page(s):863 - 876
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1323 KB)

    Second-order systems with amplitude-dependent nonlinearities can exhibit multirnodal behaviour. A method of finding the range of parameters for which this behaviour is observed is considered, and the method is then extended to predict the type of transients which occur in the system from a given set of initial conditions. The method is based on the describing function of the nonlinearity. The effe... View full abstract»

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  • Optimal linear control with input derivatives

    Publication Year: 1968, Page(s):877 - 878
    IEEE is not the copyright holder of this material | PDF file iconPDF (248 KB)
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  • Clopan: a CLOsed-Pattern ANalyser

    Publication Year: 1968, Page(s):879 - 880
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | PDF file iconPDF (170 KB)
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  • Calibration of precision d.c. potentiometers by an a.c. method

    Publication Year: 1968, Page(s):881 - 887
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (991 KB)

    The possibility of calibrating precision d.c. potentiometers on alternating current, so that an inductive divider may be used as the reference standard, is examined. It is found that the change in ratio with frequency of potentiometers is partly due to the a.c. properties of the resistance coils and partly due to e.m.f.s induced in the voltage circuit of the potentiometer, the latter effect predom... View full abstract»

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  • Two-stage inductive voltage dividers

    Publication Year: 1968, Page(s):888 - 892
    Cited by:  Papers (22)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (575 KB)

    The paper examines the theory of the 2-stage voltage transformer and shows that it not only provides a very accurate primary/secondary voltage ratio but also increases the effective input impedance of one of its primary windings to a very high value. It is shown theoretically and experimentally that these characteristics enable inductive voltage dividers to be made which have extremely small error... View full abstract»

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  • Plasma torch as a means of improving wheel-rail adhesion

    Publication Year: 1968
    IEEE is not the copyright holder of this material | PDF file iconPDF (148 KB)
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Aims & Scope

The Proceedings of the Institution of Electrical Engineers was published by the IET between 1963 and 1979.

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