Newnes Dictionary of Electronics

399 Pages·2002·17.58 MB·English

by  S W Amos

Newnes
Dictionary of Electronics
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Newnes
Dictionary of Electronics
Fourth Edition
s. w.
&llOS, CEng, BSc, MIEE
s.
R. h l 3 O S , BD, BSc, MISTC
Appendix by
w.
G. A. Dummer, MBE, CEng, FIEE
Newnes
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An imprint of Elsevier Science
Linacre House, Jordan Hill, Oxford OX2 8DP
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First published 1981
Reprinted 1982, 1986
Second edition 1987
Third edition 1996
Reprinted 1997, 1998
Fourth edition 1999
Reprinted 2000
Paperback edition 2002
Copyright 0 1999 Elsevier Science Ltd. except Appendix (pp. 359-389)
Copyright 0 1999 G. W. A. Dummer. All rights reserved
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L I
Preface to First Edition
The British Standards Institution and the International Electrotechnical
Commission have issued a number of publications containing definitions of
the terms used in electronics.
The definitions in these published standards are, however, written by
experts and intended, chiefly, for use by experts: they are therefore
authoritative and brief. Such definitions are not ideally suited to the needs
of engineers and technicians who are working in electronics, students who
are studying the subject or amateurs interested in it: this dictionary is
intended primarily for their benefit.
In this dictionary definitions are supplemented by explanatory material
whenever this would seem helpful. Some entries are therefore short essays
including diagrams: typical examples are the entries on * camera tube',
* digital computer' and *thyristor'. There are also short definitions where a
single sentence gives all the information likely to be required: the definition
of 'B battery' is an example.
The standard circuit arrangements used in electronic equipment, such as
the Hartley oscillator, are defined in words but are more readily understood
from circuit diagrams. A large number of such diagrams are therefore
included in this dictionary and the graphical symbols used in them conform
with BS 3939.
In the form of presentation adopted definitions are arranged in
alphabetical order of the initial letter of the first word. Thus 'characteristic
impedance' appears under C and not under I. Cross references are provided
to draw the reader's attention to related terms and definitions which should
assist understanding and attention is drawn to the most helpful of these by
printing them in bold italics. Technical terms used in a definition are
normally defined elsewhere in the book. An appendix giving many of the
abbreviations and acronyms used in the literature has been added and
should serve to guide a reader to the definition of a term known only by its
abbreviation.
This dictionary is associated with the 'Dictionary of
Telecommunications' by S. J. Aries and the 'Dictionary of Audio, Radio
and Video' by R. S. Roberts. These subjects are closely related with
electronics and share many technical terms. For this reason the authors of
the dictionaries collaborated during their preparation to prepare a list of
technical terms to be defined, to decide in which dictionary each term
should appear and what depth of treatment each should receive. North
American terminology was ftilly represented in this list to ensure that the
dictionaries have the widest-possible English-speaking readership. It was
agreed that some terms for common concepts should appear in all the
dictionaries to make them largely self-contained but that detailed
explanations of fundamental terms should be confined to the Dictionary of
Electronics.
Thanks are due to ITT Semiconductors and Motorola Semi-conductor
Products for providing information on short-channel MOS transistors.
S.W. Amos
1981
Preface to Second Edition
In this second edition a number of new definitions have been included and
some which appeared in the first edition have been revised or expanded.
Most of these changes were adopted to keep the dictionary au fait with
recent developments in semiconductor devices, digital techniques,
computers and microprocessors.
I gratefully acknowledge the willing help given by my son Roger and my
neighbour Pat Thwaites in the preparation of the new edition.
S.W. Amos
Broadway, 1986
Preface to Fourth Edition
In an effort to keep up-to-date with the continuous flow of developments
in electronics, the publishers decided to produce this new edition of the
dictionary to incorporate the new terminology introduced since the third
edition was published in 1996.
Because this new material is confined chiefly to the field of computing
and data-processing equipment and consists largely of acronyms, the
Appendix which lists abbreviations and acronyms has been completely
rewritten. My son, Roger, and I record our thanks to G. W. A. Dummer,
MBE, CEng, FIEE, who supplied most of the text of the new Appendix. As
for the previous edition of the dictionary, Roger prepared the camera-
ready copy of the new edition for the publishers.
S. W. Amos
Broadway, 1998
A battery (US) A battery used to provide the low-tension supply for
electron-tube heaters or filaments.
abend Short for abnormal end. In computing fatal error conditions that
require immediate termination of the user's session.
aberration In cathode ray tubes, distortion of the image caused by failure of
the electron beam to focus all points in the image accurately on the screen.
absolute permeability Of a material, the ratio of the magnetic flux density to
the magnetising force which gives rise to it.
absolute permittivity Of an insulator, the ratio of the electric flux density to
the electric field strength which gives rise to it.
absolute power level The magnitude of the power level of a signal at a point
in a transmission system, usually expressed in decibels, relative to a power
of 1 mW, known as zero power level. For example, a signal power level of
1 pW is known as -30 dB.
absolute value device A device of which the output signal has an amplitude
equal to that of the input signal but always has the same polarity
irrespective of the polarity of the input signal.
absolute voltage level The magnitude of the voltage level of a signal at a
point in a transmission system, usually expressed in decibels, relative to a
voltage of 0.775 V, known as zero voltage level. 0.775 V RMS is the
voltage corresponding to a power of 1 mW in 600 O. A reference voltage
level of 1V is sometimes used in expressing the voltage level of the output
of a microphone.
absorber circuit In a transmitter, a circuit, usually employing an electron
tube, which absorbs power from the transmitter when a break occurs in an
oscillatory circuit so preventing the formation of an arc across the break
which could cause damage.
absorption frequency meter (also known as wavemeter) An instrument for
measuring the frequency (or wavelength) of an RF signal, in which a
calibrated resonant circuit is coupled to the RF source, maximum energy
being absorbed from it when the circuit is resonant at the frequency of the
signal.
absorption modulation A method of producing amplitude modulation in
which the amplitude of the carrier is varied according to the power
absorbed from it in a resistance the value of which is made to vary in
accordance with the instantaneous amplitude of the modulating wave.
A-B test A subjective comparison of the quality of two audio or video
signals by switching alternately between the two. Two items of equipment,
e.g. hi-fi amplifiers, may be compared in this way. A three-head tape
recorder may be tested by switching alternately between the source and
playback output while recording a suitable high-quality source.
accelerated life test A form of life test so designed that the time taken to
determine the probable life of a component or device is appreciably shorter
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