摘要:

The paper describes the electrical installation in the Royal Festival Hall and illustrates some of the problems encountered in its design.Lightning protection, the power installations, and the primary, secondary and stage lighting are described, special attention being given to the development of the dimming arrangements for coldcathode lighting.The description of the sound amplification system includes arrangements for hearing-aids, simultaneous interpretation, and an unorthodox type of interval signal.Other features of the installation are the provisions made for B.B.C. sound and television broadcasts, stage signalling, cueing systems and internal telephones.

DOI:10.1049/pi-2.1953.0033

出版商:IEE    

年代:1953

数据来源: IET

摘要:

The paper describes the design, construction and test results of a 150-kV 50-c/s continuously-evacuated X-ray equipment built to replace the radium-bomb method for the radiography of circumferential welds in a hollow fabricated drum or pipe in which the interior was not accessible for the insertion of cassettes using an external source of radiation.

DOI:10.1049/pi-2.1953.0048

出版商:IEE    

年代:1953

数据来源: IET

摘要:

An important part of farm mechanization is the development of methods for drying crops artificially. Such operations being static applications in and about the farmyard, they offer scope for the employment of electricity. It is important for the electrical engineer to appreciate not only the trends of modern developments in farm crop-drying, but the basic principles by which these trends are guided. The authors are of the opinion that the trend is towards simplified methods of drying in which the maximum advantage is taken of the drying properties of unheated air and towards techniques which lend themselves to a favourable and economic use of electric heating of the air.Herbage drying is dealt with and also the likelihood of more importance being paid to hay drying. Grain drying is tending away from direct drying with high heating requirements to in-bin and platform drying where the heating requirements and the whole technique are more favourable to the all-electric idea. The platform dryer as an all-purpose machine is envisaged. Hop drying remains, of our major farm dryings, relatively inefficient and resistant to improvement in drying efficiency and technique.

DOI:10.1049/pi-2.1953.0051

出版商:IEE    

年代:1953

数据来源: IET

摘要:

In Britain transmission voltages are being increased from 132 to 275 kV, with probable extension in the near future to 400 kV. These substantial increases, which are universal, have magnified the complex insulation problems inherent in the design of h.v. power transformers and have laid emphasis on the study of electrostatic-field phenomena.In practice, the field problems encountered are much too complicated to yield to analytical methods and much too tedious to encourage graphical procedures. To obtain solutions it is necessary to resort to analogue techniques which permit of analysis in a straightforward manner and with a degree of accuracy sufficient for all engineering purposes. The paper sets forth the theory and development of the electrolytic analogue and indicates its limits of accuracy. It outlines the basic features of a field-plotting equipment, describes practical techniques of engineering problem into analogue models and examines methods of analysing the results obtained.The application of the technique to the field problems arising in h.v. power-transformer design is considered in detail. Power-frequency and impulse phenomena are reviewed and numerous illustrative examples drawn from comprehensive investigations are quoted. Resulting theoretical and practical advances are indicated and the advantages accruing from the co-ordinated design of h.v. bushing and transformer are reviewed.The analogue is shown to provide a method of speeding the development of large power transformers by affording facilities for extensive and discriminative investigations at negligible cost.

DOI:10.1049/pi-2.1953.0065

出版商:IEE    

年代:1953

数据来源: IET

摘要:

An investigation has been made into certain errors arising in electrolytic-tank systems used for field plotting. A new technique utilizing square-wave excitation and liquid probes is presented. An assessment has been made of the relative merits of various electrode-electrolyte combinations for practical use.

DOI:10.1049/pi-2.1953.0066

出版商:IEE    

年代:1953

数据来源: IET

摘要:

A great deal has been published, especially during the last decade, on cross-field generators—both metadynes and amplidynes. Much of this work has been concerned with the application of these machines in servo mechanisms or control systems rather than with the theory of the machines themselves, and, as a result, most authors only describe applications of the type of machine in which they are specially interested, and neglect the general theory of the machine itself.The object of this short study is the development of a generalized quantitative steady-state theory of cross-field machines of the metadyne-amplidyne type, in order to show the essential unity in that theory. The term “amplidyne” is normally used for cross-field generators in which the compensating winding is of just sufficient strength to neutralize the armature m.m.f. It will be shown that metadyne generators (which have a constant output-current property) and amplidyne generators (which have a constant output-voltage property) are two special modes of working of the same class of machine, and that between these limits there exist many other modes which fall between the two extremes.In order to avoid any ambiguity it should be stated that the term “metadyne” has not always been used in the same sense: it has sometimes been used to cover both constant-current characteristics and constant-voltage (amplifier) characteristics. The term is here used consistently to mean a cross-field generator having any degree of compensation other than 100%, or nearly this value, and thus having constant-current characteristics.The quantitative theory, given in Section 2, has been checked experimentally on two machines initially designed for use as a metadyne and as an amplidyne, respectively. The former had a solid yoke and salient poles, as in a normal d.c. machine, but the latter was built from punched laminations as in an a.c. machine, the windings being placed in slots. In Section 3, methods of determining on noload the constants of any cross-field machine are given. In Section 4, experimental results on load are shown to confirm the theory of Section 2, using constants derived as in Section 3, and close agreement is found to occur between theory and practice.

DOI:10.1049/pi-2.1953.0077

出版商:IEE    

年代:1953

数据来源: IET

DOI:10.1049/pi-2.1953.0078

出版商:IEE    

年代:1953

数据来源: IET

DOI:10.1049/pi-2.1953.0079

出版商:IEE    

年代:1953

数据来源: IET

DOI:10.1049/pi-2.1953.0080

出版商:IEE    

年代:1953

数据来源: IET

DOI:10.1049/pi-2.1953.0081

出版商:IEE    

年代:1953

数据来源: IET