DICTIONARY
`of
`
`ELECTRONICS
`
`SEVENTH EDITION
`
`REVISED AND UPDATED
`
`

`
`Copyright © 1999 by Rudolf F. Graf
`
`-& A member of the Reed Elsevier Group.
`
`All rights reserved.
`
`No part of this publication may be reproduced, stored in a retrieval system. or transmitted
`in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise,
`without the prior written permission of the publisher.
`
`Recognizing the importance of preserving what has been written, Butterworth-Heinemann
`prints its books on acid-free paper whenever possible.
`
`‘ “““ “ Butterworth-Heinemann supports the efforts of American Forests and the Global
`ReLeaf program in its campaign for the betterment of trees,
`forests, and our environment.
`
`Zllllfl
`
`E
`
`Library of Congress Cataloging-in-Publication Data
`
`Graf, Rudolf F.
`Modern dictionary of electronics / Rudolf F. Graf.—-7th ed.,
`revised and updated.
`p.
`cm.
`ISBN 0-7506-9866-7 (alk. paper)
`1. Electronics—Dictionaries. I. Title
`TK7804.G67
`1999
`621.381’03—dc2l
`
`99-17889
`CIP
`
`British Library Cataloguing-in-Publication Data
`A catalogue record for this book is available from the British Library.
`
`The publisher offers special discounts on bulk orders of this book.
`For information, please contact:
`Manager of Special Sales
`Butterworth-Heinemann
`225 Wildwood Avenue
`Woburn, MA 01801-2041
`Tel: 781-904-2500
`Fax: 781-904-2620
`
`‘~
`
`{
`
`For information on all Butterworth-Heinemann publications available, contact
`our World Wide Web home page at: http://www.bh.com
`
`10987654321
`Typeset by Laser Words, Madras, India
`Printed in the United States of America
`
`
`
`

`
`source language suited to the description of a specific
`class of problems.
`problem-solving language—A language that can
`be used to specify a complete solution to a problem.
`procedure—Also called an algorithm. 1. In a com-
`puter, the course of action taken in solving a problem.
`2. A precise step-by-step method for effecting a solution
`to a problem.
`procedure-oriented language—1. A program-
`ming language in which the operations to be performed
`are all executable and their sequence is specified by the
`user. This term applies to most familiar programming
`languages. 2. A programming language designed for the
`convenient expression of procedures used in the solution
`of a wide class of problems, e.g., FORTRAN, COBOL,
`APL, and C.
`process—1. Any operation or sequence of opera-
`tions involving a change of energy state, composition,
`dimension, or other property that may be defined with
`respect to a datum. The term process is used in this stan-
`dard to apply to all variables other than instrument signals.
`2. The basic unit of computation within an operating sys-
`tem. Also termed a software process to distinguish it from
`an abstract process, which is the task the software process
`implements.
`process control— 1. Automatic control of continu-
`ous operations, contrasted with numerical control, which
`provides automatic control of discrete operations. 2. The
`regulation or manipulation of variables influencing the
`conduct of a process in such a way as to obtain a product
`of desired quality and quantity in an efficient manner.
`
`convemzn 1 °°""‘"5“
`
`
`
`
`neconos
`
`Process-control system.
`
`process-control block——The data structure that
`defines a software process and its status.
`
`inputs and outputs in response to the user-programmed
`instructions in memory, and it energizes or deenergizes
`outputs as a result of the logical comparisons made
`through these instructions. 4. A computer or part of a
`computer capable of receiving data, manipulating it, and
`supplying results.
`processor status word—-Abbreviated PSW. A
`special-purpose CPU register that contains the status of
`the most recent instruction execution result, trap bit, and
`interrupt priority.
`producer’s reliability risk—The risk faced by the
`producer (usually set at 10 percent) that a product will
`be rejected by a reliability-acceptance test even though
`the product is actually equal to or better than a specified
`value of reliability.
`product detector—— A demodulator whose output is
`the product of the input signal voltage and the signal volt-
`age of a local oscillator operating at the input frequency.
`production lot—A group of (electronic) parts man-
`ufactured during the same period from the same basic
`raw materials, processed under the same specifications
`and procedures, produced with the same equipment, and
`identified by the documentation defined in the manufac-
`turer’s reliability assurance program through all signif-
`icant manufacturing operations, including final assembly
`operations. Final assembly operation is considered the last
`major assembly operation, such as casing, hermetic seal-
`ing, or lead attachment, rather than painting or marking.
`production sampling teSts——Those tests normally
`made by either the vendor or the purchaser on a portion
`of a production lot for the purpose of determining the
`general performance level.
`production tests——Those tests normally made on
`100 percent of the items in a production lot by the vendor
`and normally on a sampling basis by the purchaser.
`product modu|ator—A modulator whose output
`is substantially equal to the carrier times the modulating
`wave.
`
`professional channel——Subcarrier channel in FM
`broadcasting. Professional channels are usually 6.5 times
`the frequency of the pilot carrier, or
`they may be
`interspersed between the stereo position and 102 kHz, if
`there is no SAP (second audio program) conflict.
`professional engineer—An engineer whose edu-
`cation and experience qualify him or her to be responsible
`for important engineering work, and who is registered as
`a professional engineer by a state authority.
`profile chart—A vertical cross-sectional drawing
`of the microwave path between two stations. Terrain,
`obstructions, antenna-height requirements, etc., are indi-
`cated on the drawing.
`program—1. A sequence of instructions that tells
`a computer how to receive, store, process, and deliver
`information. 2. A plan for solving a problem, including
`instructions that cause the computer
`to perform the
`desired operations and such necessary information as data
`description and tables. 3. A prepared list of instructions,
`
`
`
`

`
`
`
`3’>>
`
`__)>
`
`
`——n——————
`
`representation. 8. A set of coded instructions that direct
`a computer to perform some specific function, yield
`the solution to some specific problem, or control a
`machine or process. 9. A sequence of instructions that will
`execute a predetermined sequence of operations. 10. An
`organized set of instructions used to control operations
`of an electronic switching system. 11. A sequence of
`user-specified instructions that result in the execution of
`an algorithm. Programs are essentially written at three
`levels: (a) binary (can be directly executed by the MPU),
`(b) assembly language (symbolic representation of the
`binary), and (c) high-level
`language (such as BASIC;
`requires a compiler or interpreter). 12. A meaningful
`assembly of encoded instructions and data formats and
`data values internal
`to the program. 13. A sequence
`of audio signals alone, or audio and video signals,
`transmitted for entertainment or information.
`program amplifier—See line amplifier.
`program assembly—-Also called translation. A
`process that translates a symbolic program into a machine-
`language program before the working program is exe-
`cuted. Several sections or different programs can also be
`integrated during this process. See also assembler.
`the
`program break—The length of a program;
`first location not used by a program (before relocation);
`the relocation constant for the following program (after
`relocation).
`program circuit——A telephone circuit that has been
`equalized to handle a wider range of frequencies than
`ordinary speech signals require. In this way, music can
`be transmitted over telephone wires.
`program control—A control system that automat-
`ically holds or changes its target value on the basis of
`time, to follow a prescribed program for the process.
`program counter—A CPU register that specifies
`the address of the next instruction to be fetched and
`executed. Normally it is incremented automatically each
`time an instruction is fetched. See also program register.
`program-distribution amplifiers—A group of
`amplifiers fed by a bridging bus from a single source.
`Each amplifier then feeds a separate line or other service.
`program e|ement—The part of a central computer
`system that performs the sequence of instructions sched-
`uled by the programmer.
`program failure alarm—In broadcasting stations,
`a relay circuit that gives a visual and aural alarm when
`a program fails. A delay prevents the relay from giving
`a false alarm during the silence before and after station
`identification or other short breaks.
`program flowchart—A flowchart that describes the
`control flow—the order in which the various program
`steps are executed~—within any computer program or
`module.
`program generator—A program that enables a
`computer to write other programs automatically.
`
`Program-distribution amplifiers.
`
`program instruction —A group of letters, symbols,
`or numbers that direct a computer to perform an oper-
`ation. (The instruction may also include one or more
`addresses.)
`program |evel—The measure of the program signal
`in an audio system. It is expressed in volume units (VU).
`program |ibrary—A collection of available com-
`puter programs and routines.
`program |inkage—In a computer, efficient use
`of all registers and development of subroutines so that
`there is smooth, economical transition from one program
`segment to another, and memory capacity is conserved.
`program loop—A series of computer instructions
`that are repeated until a terminal condition is achieved.
`programmable —That characteristic of a device that
`makes it capable of accepting data to alter the state of its
`internal circuitry to perform a specific task(s).
`programmable calcu|ator— 1. A calculator whose
`operation is controlled by programs stored in its mem-
`ory. 2. Electronic calculator capable of performing preset
`sequences of computations. 3. One that can learn a repet-
`itive series of operations; that is, can be programmed by
`various means to handle a series of steps so that only
`variable information need be entered into the calculator.
`programmable communications processor-
`A digital computer that has been specifically programmed
`to perform one or more control and/or processing func-
`tions in a data communications network. As a self-
`contained system, it may or may not include communica-
`tions line multiplexers, line adapters, a computer system
`interface, and online peripherals. It always includes a
`specific set of user-modifiable software for the communi-
`cations function.
`programmable controller—Abbreviated PC. 1. A
`control machine based on solid—state digital logic and built
`of computer subsystems, and primarily intended to take
`the place of electromechanical relay panels in applications
`in which rewiring would be made necessary by periodic
`changes in sequence. This type of controller is particularly
`useful in the control of processes, materials handling, and
`certain machine functions. 2. A controller whose opera-
`tion is determined by codes or instructions programmed
`into it by the user. 3. A solid—state control system that
`has a user—programmable memory for storage of instruc-
`tions to implement specific functions, such as 1/0 control
`logic, timing, counting, arithmetic, and data manipulation.