摘要:

A quantitative theory is presented to explain the shape of the output waveforms when square-loop ferrite cores are switched. This is based on the qualitative theory of Menyuk and Goodenough.3Various useful equations arising from the theory are deduced, and it is shown that the agreement with experiment is reasonable. The theory indicates which parameters of the material need to be known in order to predict its behaviour.

DOI:10.1049/pi-c.1959.0023

出版商:IEE    

年代:1959

数据来源: IET

摘要:

It is shown that the various stability criteria for linear systems can be conveniently obtained, and interrelated, by means of continued fractions. A new canonical form for a Hurwitz polynomial as a product of continued fractions is also given, together with an alternative set of determinantal criteria with determinants of about half the order of the Hurwitz determinants.

DOI:10.1049/pi-c.1959.0024

出版商:IEE    

年代:1959

数据来源: IET

摘要:

Breakdown voltages have been measured with and without the irradiation from 0.5 mg of radium. Spheres of diameters 2 to 25 cm were used and some experiments were made with parallel-plate electrodes. The irradiation lowered the breakdown voltage by as much as 4% in some circumstances. A maximum effect was obtained with a particular gap length, and this length depended on the size of the sphere electrodes.

DOI:10.1049/pi-c.1959.0025

出版商:IEE    

年代:1959

数据来源: IET

摘要:

The paper sets out a simple procedure of general application whereby any function represented by a power series may be replaced by a sequence of rational functions, the advantage of such representation being that in many cases the rational functions converge much more rapidly than does the series. It often happens that the rational-function form continues to represent the given function accurately for values of the argument which make the series form diverge.The procedure is illustrated with a worked example, and the method is then applied to determine a simple expression for the maximum electric intensity between two equal charged spheres, when the sphere-gap is small compared with the diameters.

DOI:10.1049/pi-c.1959.0026

出版商:IEE    

年代:1959

数据来源: IET

摘要:

The process of obtaining the transient response of band-pass filters to a suddenly applied carrier of frequency equal to or differing from the mid-band frequency of the filter is shown to be simplified by the use of Laurent's low-pass band-pass transformation together with suitable approximations. The method is illustrated by an analysis of them-derived band-pass filter. The effect of elements possessing a finite Q-factor is considered and an estimation of the errors due to the approximations used is made.

DOI:10.1049/pi-c.1959.0027

出版商:IEE    

年代:1959

数据来源: IET

摘要:

A method proposed by the Services Electronics Research Laboratory is analysed in detail, and expressions are derived for the efficiency under a variety of conditions. It is shown that, subject to reasonable limitations on the intermediate-frequency spacing, a polycrystalline ferrite should behave in many ways like a single crystal sample and that the S.E.R.L. measurements on magnetization can be explained by assuming a basic line width of a few gauss and a spread in resonant fields from point to point in heterogeneous samples. Owing to a remarkable property of the structure of the formulae, this spread in resonance does not degrade the effective permeability, although the measured value is reduced by a factor of about a hundred.On the figures presented, the tentative conclusion is reached that the conversion efficiency is some 14 dB worse than acceptable conventional crystals will give, although the figures may be capable of improvement. No calculations are made on noise figure.

DOI:10.1049/pi-c.1959.0028

出版商:IEE    

年代:1959

数据来源: IET

摘要:

An outline is given of a method for calculating the magnetic field of rotating machines. As a first stage in this work the field of a tubular current has been calculated, and curves are given for a particular example of such a current.

DOI:10.1049/pi-c.1959.0029

出版商:IEE    

年代:1959

数据来源: IET

摘要:

The paper describes a general perturbation method for determining the gain of travelling-wave ferromagnetic amplifiers. By use of the method, the gain is determined for an amplifier employing a circular waveguide and an axial ferrite rod of small cross-section. The efficiency of such an amplifier is shown to be low, and a practical version would demand the use of larger rod cross-section and/or a slow-wave structure. Other possible waveguide configurations for amplifiers are briefly mentioned, together with certain practical aspects of construction.

DOI:10.1049/pi-c.1959.0030

出版商:IEE    

年代:1959

数据来源: IET

摘要:

The natural frequencies of an electrical network are defined, and the number of these natural frequencies is called theorder of complexityof the network.RLCnetworks are considered, and the order of complexity, σ, is shown to be given byσ =BL+N+S−SC−SCR.Here,BLis the number of inductors in the network,Nis the number of nodes,S,SCandSCRare the connectivities, i.e. the number of separate parts of, respectively, the given network and those subnetworks formed of the capacitors only and of the capacitors and resistors only. Other expressions for σ are also obtained.It is shown that this order of complexity is also the number of arbitrary integration constants in the complete solution of the network equations, and the number of dynamically-independent network variables. Complete sets of such dynamically-independent variables are obtained by a process of elimination from the network equations. A particular type of complete set is classified topologically, such sets being made up of voltages across capacitors forming a forest of the capacitor-only network obtained by open-circuiting all the resistors and inductors, together with the currents through inductors forming a set of chords of the inductor-only network obtained by short-circuiting all the capacitors and resistors.

DOI:10.1049/pi-c.1959.0031

出版商:IEE    

年代:1959

数据来源: IET

摘要:

In designing machines and apparatus with solid magnetic circuits, flux/time curves have often to be predetermined to secure a desired rapidity of response. Their prediction has hitherto been uncertain, especially in the presence of saturation.In the paper, an attempt is made to derive the equations for the rise of flux and current on the basis of a limiting non-linear theory. This results in an original treatment and gives a greater insight into the physical phenomena involved in the magnetization of a core due to impact excitation. The results obtained from these equations compare favourably with test results.

DOI:10.1049/pi-c.1959.0032

出版商:IEE    

年代:1959

数据来源: IET