DOI:10.1049/ree.1979.0011

出版商:IERE    

年代:1979

数据来源: IET

DOI:10.1049/ree.1979.0012

出版商:IERE    

年代:1979

数据来源: IET

DOI:10.1049/ree.1979.0013

出版商:IERE    

年代:1979

数据来源: IET

摘要:

The conventional hybrid computer, although of immense value in simulation, has always suffered from one major defect, namely the need for a patchpanel with its attendant problems of patching, debugging and careful maintenance. This paper describes the development of a new machine in which the operator communicates with the analogue sub-system via a graphics terminal. A minicomputer with flexible disk backing store is arranged to interrogate the graphics terminal on which a block diagram of the system to be simulated has been drawn up by the operator. Numerical data related to the blocks are inserted via a keyboard/v.d.u. Changes in data and/or topology can be implemented at considerable speed by the operator. The machine has been extensively tested and the results of one such test have been included in the paper. It has been shown that GRAPHIC is a thoroughly ergonomic and reliable machine, capable of expansion, extension and improvement and that it could form the basis of an improved commercial hybrid computer.

DOI:10.1049/ree.1979.0014

出版商:IERE    

年代:1979

数据来源: IET

摘要:

A 13-channel p.cm. system forms a significant part of the BBC's national radio distribution network, and is used to carry high-quality soundprogramme material hundreds of miles with minimal impairment from noise, interference and distortion.High-quality analogue-to-digital converters (a.d.c) and digital-to-analogue converters (d.a.c) are required for use in sound-programme links, and other applications for these converters, such as digital sound studio equipment, can be foreseen, To date, the BBC has used 13-bit a.d.cs and d.a.cs developed within the Corporation. The next generation of digital equipment is likely to require coders and decoders giving 14 bits/sample or even higher resolution.In this paper, some of the defects which may be encountered with various types of a.d.c. and d.a.c. are discussed, and the merits of different types of converter for high-quality sound are considered.

DOI:10.1049/ree.1979.0015

出版商:IERE    

年代:1979

数据来源: IET

摘要:

The more significant sources of electrical interference are outlined and the means whereby they can couple into electronic equipment and systems are described. Estimates are given of the levels of disturbance to be expected in different parts of instrumentation and control systems. Design and installation practices which need to be followed to avoid the unwanted effects of interference sources are outlined. Methods for testing units are described, followed by their extension to complete systems. Brief descriptions are given of an interference test unit for injecting interference and a pulse generator.

DOI:10.1049/ree.1979.0016

出版商:IERE    

年代:1979

数据来源: IET

摘要:

Several recent interference investigations are described in some detail. They demonstrate that the technique of injection of radio frequency currents into the earth is effective in locating the weak points in system screens. The use of suitable cables, connectors, filters and remedial techniques can transform what appears to be in some cases a useless system into a trouble-free one. The use of a specially developed pulse generator is shown to be particularly effective when investigating problems in digital systems.

DOI:10.1049/ree.1979.0017

出版商:IERE    

年代:1979

数据来源: IET

摘要:

A number of distinct ways of performing near real-time spectrum analysis by ‘hardware’ are outlined in block-schematic form. It is shown that these are theoretically equivalent, but differ substantially in their design implications and interface requirements.

DOI:10.1049/ree.1979.0018

出版商:IERE    

年代:1979

数据来源: IET

摘要:

Ideally electromagnetic compatibility should be designed into asystem abinitio rather than as a result of tests and modifications at a later date. This requires a broad awareness of e.m.c. technique on the designer's part which is often only acquired by experience. Based on experience both of general design and e.m.c. work several areas of knowledge are highlighted whose neglect contributes to present-day e.m.c. problems.

DOI:10.1049/ree.1979.0019

出版商:IERE    

年代:1979

数据来源: IET