摘要:

An analysis has been made and a design procedure established for fuses other than those using round wire and with, or without, a restricted cross-section for part of the fuse length. Fuses of restricted section are, however, the major interest since they may be used to give different current/time characteristics by varying their dimensions. These different characteristics may be predicted accurately by the method indicated in the paper. In all the cases of semi-enclosed tin-strip fuses investigated in this way very close agreement between predicted and experimental results has been obtained.

DOI:10.1049/pi-c.1961.0002

出版商:IEE    

年代:1961

数据来源: IET

摘要:

The solution of a system of simultaneous linear equations may obtained by inspection of an associated system of nodes and connecting branches called a ‘signal flow-graph’. This provides alternative to conventional algebraic methods which is of particular interest in the case of network analysis, since the flow graph can be set up directly by inspection of the network without having to formulate the associated equations. In the paper the formal theory of flowgraph analysis is developed and applied to certain aspects of feedback theory, and it is shown that the classical results of Bode can be obtained and generalized relatively simply by this approach.

DOI:10.1049/pi-c.1961.0003

出版商:IEE    

年代:1961

数据来源: IET

摘要:

A theoretical calculation is given of the amplitude probability distribution to be expected on an ionospheric v.h.f. forward-scatter circuit due to reflections from meteor trails alone. The analysis is based on the addition of a large number of signals with a frequency of occurrence inversely proportional to the square of their amplitude, and will therefore apply to other problems in which this relation holds. The calculated distribution is compared with a small number of practical results, and a method is outlined for deriving the relative proportion of meteoric and turbulent-scattering components in the signal.

DOI:10.1049/pi-c.1961.0004

出版商:IEE    

年代:1961

数据来源: IET

摘要:

A brief outline of the theory of the lapping operation for high-voltage single-core paper-lapped cable is given, showing the stability conditions which the insulation thickness must satisfy in order that bending of the cable on the reel or capstan does not cause any damage to the insulation itself. An example of the design of a high-voltage cable is considered, showing the application of the theory outlined and its practical use.

DOI:10.1049/pi-c.1961.0005

出版商:IEE    

年代:1961

数据来源: IET

摘要:

The flexural vibrator, designed to vibrate at about 1 kc/s, basically consists of identical cantilever arms extending from a common area form a symmetrical element. Two distinct shapes have been considered—the H and the ‘zigzag’. Some of the H elements have uniform cross-section while others are arranged to have most of their mass at the free ends in order to reduce the frequency for a specimen given length. The ‘zigzags’ have folded arms of any number of sections (increasing the number of sections reduces the frequency).The theory of the various forms and their frequency equations are derived. Conditions for perfect balance of the reactions at the supports are discussed.Measurements have been made on H and ‘zigzag’ forms made from quartz slices ZYbΦ(Φ = 0−10°) and on ‘zigzag’ form from e.d.t.XYltlΦ, 90°, 90°. Frequency, temperature behaviour, Q-factor and displacement patterns of the elements are compared with theory. Since some of the conventional driving methods proved unsatisfactory short Section is included on circuits.

DOI:10.1049/pi-c.1961.0006

出版商:IEE    

年代:1961

数据来源: IET

摘要:

A type of binary digital code is described which is easily generated by computer circuits. The important properties of these codes are described, and various electronic applications enumerated.

DOI:10.1049/pi-c.1961.0007

出版商:IEE    

年代:1961

数据来源: IET

摘要:

The paper describes the application of frequency-response concepts to the analysis of a synchronous machine damper in so far as it affects the stability of the machine. The analysis of damper effects is based on Park's equations. Small-displacement theory is introduced toorganize the equations into the correct form for frequency-response computation.Nyquist diagrams are used to show the stabilizing effect of a damper and to illustrate the method of optimizing damper parameters.

DOI:10.1049/pi-c.1961.0008

出版商:IEE    

年代:1961

数据来源: IET

摘要:

This paper examines analytically the field between equal stator and rotor ducts when displaced from each other and evaluates, for any relative position, the total flux crossing the air-gap and the amount entering the sides of each duct. The flux entering the sides of the stator ducts in a.c. machines varies at supply frequency and produces eddy currents the path of which is not restricted by the direction of the laminations and which consequently give rise to considerable loss. With relative displacement of the ducts the fluxes entering the two sides of a duct become unequal and produce an axial magnetic force of engineering importance.Numerical values are given for the variation of gap permeance and magnetic centring force, and are plotted in curves directly applicable to design calculation for ratios of duct to gap width varying from ½ to 5 and for any relative displacement.

DOI:10.1049/pi-c.1961.0009

出版商:IEE    

年代:1961

数据来源: IET

摘要:

Over the past decade and a half there have been proposed three schemes of control for electricity supply systems interconnected through tie lines. In chronological order they are the speed-governed system with frequency biasing, the time-governed system and the load-phase energy control.The paper describes computer studies which compare the three systems using a performance index of the integral square error. Certain conclusions are drawn by applying this criterion both to the frequency error of the isolated system and to the tie power-flow error of the interconnected system.

DOI:10.1049/pi-c.1961.0010

出版商:IEE    

年代:1961

数据来源: IET

摘要:

An expression for the magnetic excitation inside a cylindrical thin-film ferromagnet is derived, and a Table of computed values is given. The results are considered to be relevant to work on thin ferromagnetic films for digital-storage applications.

DOI:10.1049/pi-c.1961.0011

出版商:IEE    

年代:1961

数据来源: IET