DOI:10.1049/esej:19930030

出版商:IEE    

年代:1993

数据来源: IET

摘要:

A survey of recent work on electrical impedance tomography as presented at a recent IEE colloquium.

DOI:10.1049/esej:19930031

出版商:IEE    

年代:1993

数据来源: IET

摘要:

In recent years the Rogowski-coil method of measuring electric current has developed from a ‘laboratory curiosity’ to a versatile measuring system with many applications throughout industry and in research. The technique possesses many features which offer an advantage over iron-cored current measuring devices and these are well illustrated by considering how it can be used for measuring transient currents. The paper describes the principle of operation of Rogowski coils and the practical aspects of using them and gives several examples of their use in making transient measurements. The Rogowski coil is a conceptually simple device. Its theory of operation illustrates some basic principles of electromagnetism applied in a practical device. The coil itself provides an elegant demonstration of Ampère's Law and, because of its inherent linearity, the response of a coil under extreme measuring situations is much easier to treat theoretically than iron-cored measuring instruments. The educational aspects of studying Rogowski coils should not be overlooked.

DOI:10.1049/esej:19930034

出版商:IEE    

年代:1993

数据来源: IET

摘要:

Alan Dower Blumlein was a remarkably versatile, prolific and creative engineer whose type of genius has had few equals this century. Following early work on telephony, during which he developed a transformer-bridge network, he turned his attention to audio engineering, developing moving-coil microphones and wax cutters which circumvented patents held by Bell Laboratories and inventing a system for binaural recording. Blumlein was largely responsible for the logical development of the overall system and transmitted waveform for the world's first public, all-electronic television service but also contributed many of the component circuits, such as an efficient line-frequency scanning circuit, the ‘Miller’ integrator, the long-tailed pair and the bootstrap circuit. Before his death in an air crash he had made significant contributions to the development of airborne interception radar, microwave radar and H2S ground-mapping radar. This paper comprises shortened versions of the papers presented on 26th October 1992 at a Discussion Meeting, Exhibition and Lecture on ‘The life and work of A. D. Blumlein’, organised by IEE Professional Group S7 and held at the IEE, London, to mark the 50th anniversary of Blumlein's death on 6th June 1942.*

DOI:10.1049/esej:19930036

出版商:IEE    

年代:1993

数据来源: IET

DOI:10.1049/esej:19930037

出版商:IEE    

年代:1993

数据来源: IET

DOI:10.1049/esej:19930038

出版商:IEE    

年代:1993

数据来源: IET

DOI:10.1049/esej:19930039

出版商:IEE    

年代:1993

数据来源: IET

DOI:10.1049/esej:19930040

出版商:IEE    

年代:1993

数据来源: IET

DOI:10.1049/esej:19930041

出版商:IEE    

年代:1993

数据来源: IET

摘要:

The origins of the Year in Industry scheme are traced, its progress over the past seven years or so described and the reasons for its success given. The article highlights the importance of industry-based training for pre-university engineers and gives practical examples of cost-efficient training projects with views from employers and students. The mutual benefits to industry and university-based students of set project work during the one year placement programme are underlined.

DOI:10.1049/esej:19930044

出版商:IEE    

年代:1993

数据来源: IET