Electrical Engineers, Proceedings of the Institution of

Present-day theory of uniform cylindrical dielectric-rod antennas rests on the three theoretical treatments of Horton, Bouix and Fradin (leaky-guide theory), and on Brown's end-fire theory. A digression on the general relationship between Schelkunoff's equivalence principle and the vector Kirchhoff formula reveals that these radiation formulas may only be applied to regions in which the vector pot... View full abstract»

The paper is an analysis of a radar-signal-processing system¿the frequency-scanned filter¿which is designed to extract both range and velocity information from a single echo. The transmitted signal is a pulse train, which can be represented as a sequence. The echo is processed in a tapped delay line, with the taps weighted according to another sequence. The tap output is modulated by phase-coher... View full abstract»

In many small telemetry systems it is convenient to use information derived from a transducer to modulate the period of a multivibrator, the multivibrator waveform being used in turn to modulate a radio or line link. In this way, the measurement is easily made in digital form, and errors due to nonlinearity of the carrier modulator are removed. The use of multivibrators in this application is cons... View full abstract»

It has been shown previously that ternary functions can be constructed from binary elements. The paper proposes the application of Boolean algebra to a generalised procedure for the design of 3-valued functions using binary elements. The final logical layout is essentially symmetrical and uses complementary electronic devices. Component tolerance is the same as that for a binary system. The partic... View full abstract»

Residual attenuation equalisation of broadband coaxial-cable systems has been achieved elsewhere by a set of harmonic cosine characteristics based on an almost linear frequency scale. This method is, however, not efficient for systems which exhibit high distortion near the bandedges. A simple analysis of measured characteristics yields the requirements for suitably transforming, or `warping¿, the... View full abstract»

An improved method is described for adjusting medium-wave directional-antenna systems containing high radiators (of the order of ¿¿). It is pointed out that the determination of radiator driving-point impedances corresponding to the desired radiation pattern requires special consideration; namely, the radiation pattern determines the relationship between radiator currents near the current maximu... View full abstract»

Several boundary-value problems associated with the planar-spiral geometry are considered. A source-excited-sheath problem is formulated exactly, and a formal solution in terms of Hankel's inverse transform is presented. The approximate form of the current density on the sheath structure is obtained. A push-pull-excited 2-arm thin-wire antenna is discussed next. It is found that the approximate cu... View full abstract»

The paper investigates induction motors running at constant speed and fed by invertors. It is based on linear 2-axis theory, and shows that an exact equivalent circuit can be drawn which includes a back e.m.f. opposed to the applied voltage, as in the synchronous motor. A rigorous analysis leads to explicit expressions in forms suitable for computation of the axis currents as time functions; sampl... View full abstract»

Newton's method is adapted to the solution of load-flow problems, and a simple condition for its convergence is derived. It is shown that the fast convergence rate justifies its use, despite the fact that it needs more memory space than methods used at present. View full abstract»

A simple method is proposed whereby the formulas for the transient conductor-temperature rise above ambient of a buried cable, following the application of a constant load, may be modified in order to take account of the variation of the electrical resistivity of the conductor with temperature during the transient. The result is an upper bound for the conductor transient that is more accurate than... View full abstract»

Currents in resonant circuits containing nonlinear elements, and amplitudes of oscillations in other nonlinear systems with periodic forcing functions, display two modes in certain ranges of frequency and amplitude of the forcing functions. The characteristics of the transition from one mode to another in an RLCcircuit are affected by the changes in parameters, and at the instants of time when the... View full abstract»

A canonical form for a multivariable linear control system is described. This canonical form is important because it enables a linear-feedback law to be chosen to produce arbitrary characteristic modes in the closed-loop system. The computational difficulties and methods suggested for minimising then are discussed. View full abstract»

The diagnosis of randomly occurring faults in complex electronic equipment is a difficult task which is generally not done well. The paper reviews some of the work on the content of the fault-diagnosis training course. In particular, the approach of the Technical Training Command of the Royal Air Force is discussed. Research has shown that the teaching of electronic theory is of much less importan... View full abstract»

Heat energy may be used directly to produce electrical work in devices having no moving parts, by employing the properties of ferromagnetic substances near their Curie points. While thermomagnetic generators proposed in the past had poor theoretical efficiencies, the study discloses an improved generator having a circuit arrangement which allows the load current to assist in obtaining a better the... View full abstract»

Voltage impact excitation of a solid iron core creates eddy currents in the core, retarding the rise of flux. An analysis of the problem involves the simultaneous solution of partial and ordinary differential equations. The boundary condition for the partial differential equation contains an unknown quantity, which is variable with respect to time in the ordinary differential equation associated w... View full abstract»