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`‘ ELECTRONICS
`ENGINEERING
`
`DICTIONARY
`
`.uflfii‘ H
`
`L
`
`•
`
`•
`
`STEVEN M. KAPLAN
`
`

`

`Copyright r 2004 by Jolm Wiley & Sons, Inc. All rights reserved.
`
`Pub ished by Jolm \\'i ley & Sons, Inc., Hoboken, New Jersey.
`Published simultaneously in Canada.
`
`'\o part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by
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`under Section Io- or I 08 of the 1976 United States Copyright Act, without either the prior written
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`6011 , fax (201 ) 748-6008.
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`Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in
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`completeness of the contents of this book and specifically disclaim any implied warranties of !
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`LibrmJ• of Congress Catalogi11g-i11-P11blicatio11 Data is available.
`
`Kaplan, Steven M.
`
`Wiley Electrical and Electronics Engineering Dictionary
`
`ISBN 0-471-40224-9
`
`Printed in the United States of America.
`
`10 9 8 7 6 5 4 3 2
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`I!
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`contact arc
`
`142
`
`content provider
`
`switch, or relay. Also called electric contact (2). 4. The
`establishment of a communication. 5. In radars, the in itial
`detection of a scanned object.
`contact arc An arc that forms between electric contacts when
`a circuit is opened.
`contact arcin g The fonnat ion of a contact a rc.
`contact area The surface area shared by electric contacts
`when a circuit is closed.
`contact blade A flat moving conductor used as an electric
`contact.
`contact bounce An undes ired condition in which there is a
`spontaneous opening, or the intennittent opening or closing
`of contacts, when such contacts are moved to the open or
`closed position. Also called bounce (2).
`contact button A button used as an electric contact.
`contact chatter The continuous, rapid, and undesired opening
`and closing of electric contacts. May be caused, for in(cid:173)
`stance, by contact bounce. Also cal led chatter (2).
`contact clip A clip which grasps a contact blade, to close a
`circuit.
`contact electromotive for ce Same as contact emf.
`contact emf A potential difference that is developed between
`contacts that are made of two dissimilar materials. This po(cid:173)
`tential difference may be a few ten ths of a volt. Also known
`as contact electromotive force, contac t potential differ(cid:173)
`ence, contact potential, or Volta effect.
`contact erosion In electric contacts, the gradual loss of mate(cid:173)
`rial due to sparks, arcs, and the such. The add ition of cad(cid:173)
`mium to an alloy used in contacts may help reduce such ero(cid:173)
`sion. Also cal led electrical erosion.
`contact follow The additio nal distance that contacts travel
`together, after their initial contact. Also called contact
`overtravel.
`contact force I. The force holding contacts together. 2. The
`fo rce a moving contact exerts on a stationary contact.
`contact gap The maximum distance between contacts, when
`in the open position. Also called contact separation.
`Contact Image Sensor A image sensor with limited resolu(cid:173)
`tion uti lized in scanners which are smal ler and less expen(cid:173)
`sive than those utilizing CCDs. Its abbreviation is CIS .
`contact materi al A material that can serve as an electric
`contact. Such materials may be metals such as copper, si l(cid:173)
`ve r, gold, or pa lladium, or an alloy based on these or other
`suitable metals. Contac t materi als should have high them1al
`and electric conductivities, mi nimum sticking tendencies,
`and high resistance to corrosion, among other characteris(cid:173)
`tics.
`contact microphone A microphone, such as a throat micro(cid:173)
`phone, which picks up vibrations by being in direct contact
`with the body producing them. Such microphones may be
`used, fo r instance, when extraneous noise is a problem.
`contact noise A disturbance, due to fluctuating resistance,
`produced at the point where two meta ls or a metal and a
`semiconductor are joined.
`contact ove rtravel Same as contact follow .
`contact piston A piston, which as it slides, maintains contact
`with the inner walls of a waveguide at all times. Also called
`contact plunge r.
`contact plunger Same as contact piston .
`contact potential Same as contact emf.
`contact potenti al difference Same as contact emf.
`contact pressure The pressure holding contacts together.
`contact protection The use of a contact protector.
`contact protector A component, device, or system utilized to
`suppress the arc that forms between electric contacts when a
`
`circuit is opened. A capacitor, for instance, may be used for
`this purpose.
`contact rectifier A rec tifier wh ich uti lizes one or more metal
`disks coated wi th a semiconductor layer. This layer may
`consist of selenium, copper oxide, or another suitable semi(cid:173)
`conductor. The rectification occurs as a result of the greater
`conducti vity across the contact in one direction than the
`other. Also called semiconductor rectifier (1 ), metallic(cid:173)
`disk rectifier, dry rectifier, or dry-disk rectifier.
`contact resistance The resistance between two contacts when
`a circuit is closed . This resistance is very small, usua lly a
`fraction of an ohm.
`contact sensor A device which detects objects through physi(cid:173)
`cal contact with them. These sensors may be used in robots.
`for example, to detennine the location, identity, and orienta(cid:173)
`tion of parts to be assembled.
`contact separation Same as contact ga p.
`contact spark A spark that fom1s between electric contacts
`when a circuit is opened.
`contact sparking The fonnation of a contact spa rk.
`I . A thi n and fle xi ble wire ut ilized to make
`contact wire
`electric contact. Used, for instance, to make electric contact
`on the surface of a semiconductor. 2. A wire utilized to
`make electric contact.
`contactless smart card A smart card, such as a proximity
`card, which does no t have to come into contact with the de(cid:173)
`vice reading it.
`contactless smart card reader A reader, such as a proximity
`card reader, utilized to detect data contained in contactless
`smart ca rds.
`I . A heavy-duty relay utilized to control and/or
`contactor
`switch electric circuits, such as power circuits. Also call ed
`power rel ay (2). 2. In a control system, a de vice uti lized to
`connect and disconnect a component, circuit, device, piece
`of equipment, mechanism, or system from a source of
`power.
`contamin ant An undesi red material or substance that can
`adversely affect the properties of a component, circuit, de(cid:173)
`vice, piece of equipment, system, material, or medium.
`content Infonnation, especiall y that which is avai lable online,
`which may be any combination of tex t, audio, video, fi les, or
`the like.
`content-addressable memory Computer memo ry which is
`accessed by content rather than by add ress.
`It is often used
`in memory-manage ment units, and comparison logic is in(cid:173)
`cluded with each bit of storage. Its acronym is CAM. Also
`known as content-addressable storage, active memory,
`active storage, associative storage, or associative mem(cid:173)
`ory.
`content-addressable storage Same as co ntent-addressable
`memory.
`content aggregator An entity that gathers Infonnation from
`multiple Web sites and provides said content to others.
`Such content, for instance, can help keep users more time at
`a the collector's site, might be offered as a premium service,
`or may be sold to content providers.
`content !liter A program or utility which seeks to detect
`advertising and other bothersome or undesirable content be(cid:173)
`fo re its loaded onto a Web page being accessed. Such a
`program, for instance, can filter Web page content, protect
`privacy, prevent pop-up ads from appearing, avert banner
`ads, eliminate certain JavaScript, stop animated G!Fs, turn
`off ActiveX, disable Web bugs, and so on. Also called Web
`filter, Web content fllt er, Intern et filter, or blockin g
`softwa re.
`co ntent provider An entity that provides infom1ation content
`for the Internet, or for software-based products, such as CD(cid:173)
`ROMs. Such infonnation may be any combination of text,
`
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`
`

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`
`task swapping
`
`774
`
`techn olc~
`
`task swa pping The act of changi ng from one task (2) to
`anoth er by copyi ng or saving the data of one program, then
`loading another program.
`task switching The act of changing from one task (2) to
`another. For instance, the switching fro m a word-processing
`program to a Web browser, with both programs runn in g be(cid:173)
`fore and after the switch. Also called context switching.
`taskbar A toolbar which displays the applications which are
`currently runni ng, in add ition to providing access to oth er
`applications. which may have a small icon present. A user
`simply clicks with the mouse, or its equi valent, to make se(cid:173)
`lections. There may also be oth er information present, such
`as the time and date, status of a modem, and so on . A task(cid:173)
`bar may be adjusted in size, and is usuall y located at the bot(cid:173)
`tom of a comp uter screen , but can be placed elsewhere.
`Also spelled task bar.
`taut-band meter A meter, such as certain gal vanometers,
`whose movi ng element is suspended and kept taut. For in(cid:173)
`stance, such a meter may incorpo rate a coil whose move(cid:173)
`ments or twisti ng are correlated to its output readings.
`I. Chemical symbol for terbium. 2. Abbrev iation of
`Tb
`terabit.
`TB Abbrev iation of terabyte.
`Tb it Abbreviation of terabit.
`Tbps Abbreviation of terabits per second.
`TBps Abbreviation of terabytes per second .
`Tbyte Abbre viation of terabyte.
`Tc Chemical symbol fo r technetium.
`TC Abbrev iation of temperature coefficient.
`TCG Abbreviation of time-code generator.
`TCM Abbrev iation of Trellis-Coded Modulation.
`TCO Abbreviation of total cost of ownership.
`TCP Abbreviation of Transmission C ontrol Protocol. Within
`the TCP/I P protocol , the protocol which handles the task of
`delivering the data. TCP keeps track of the packets that a
`given message is divided into, to ensure proper routi ng, and
`that the entire message is properl y reassembled. TCP works
`at the transport-layer within the OSI model. Also called
`TCP protocol.
`TCP/IP Abbreviation of T ransmission Control Protocol over
`Internet Protocol. A set of protocols which enable different
`types of computer syste ms to communicate via differen t
`types of computer networks. TCP works at the transport(cid:173)
`layer within the OSI model, wh ile IP does so at the network
`layer. The TCP/IP suite may include other protocols, such
`It is currently the most widely used pro(cid:173)
`as UDP. or RTSP.
`tocol for de li very of data .over networks, including the Inter(cid:173)
`net. Also cal led TCP/IP protocol.
`TCP/IP protocol Same as TCP/IP.
`TCP/IP stack A group of protocols working together withi n
`TCP/IP. Such a stack, in add ition to TCP and IP protocols,
`may include DHCP, UDP, FTP, RTSP, and so on.
`TCP protocol Same as TCP.
`TCS I. Abbrev iation of trusted computer system. 2. Abbre(cid:173)
`viation of transmission convergence sublayer.
`TCXO I. Abbrev iation of temperature-compensated crystal
`oscillator.
`2. Abbreviation of temperature-controlled
`crystal oscillator.
`TD-SCOMA Abbreviation of time-d ivision synch ronous
`code di visio n mul tiple access. A technology combini ng
`TOMA and CDMA in a 3G technology.
`TDD I. Abbreviation of Telecommunications Device for the
`Deaf. 2. Abbrev iation of time-division duplexing. 3. Ab(cid:173)
`breviation of time-division duplex.
`TDES Abbreviation of Triple DES.
`
`I. Abbreviati on of time-division multiple x i c ~
`TDM
`2. Abbreviation of time-division multiplex. 3. Abbre'
`ti on of time-division multiplexer.
`TDMA Abbreviation of time-division multiple access.
`1. Abbrevia tio n of
`TDR
`time-domain rellectom ec
`2. Abbreviation of time-domain reflectometer. 3 . . -.·
`breviation of time-delay relay.
`TDS I. Abbreviation of time-division switching. 2. Ab!T:
`viation of time-dela y spectrometry.
`Te Chemical symbol for tellurium.
`TE Abbreviation of terminal equipment.
`TE mode Abbreviation o f transverse electric mode.
`TE wave Abbreviation of transverse electric wave.
`TEA laser Abbrev iation of transv ersel y-excited atmosp hecn
`laser .
`teach box A de vice which is utilized to program mech an: .. _
`motions into computers, such as robot controllers. Used, frr
`instance, for subsequent task exec uti on by program ma~ !
`robots.
`teach pendant A handheld control panel utilized to gu ide t.
`robot through the steps required to complete a task.
`II •
`connected to the robot by means of a suspended cable .
`. ~.
`motions are recorded by the robot fo r future reference.
`teamware Software designed to faci litate groups of peop:
`often in different locations, to work together on one me._
`projects. Such software includes email ing, scheduling, fi~
`transferring, application shari ng, conferencing, the use of_
`whiteboard, and so on. Also called groupware, or worl;(cid:173)
`group software.
`tear down
`In co mmuni cations, to end a physical or logic:..
`connection, such as that util ized for a telephone call or ne1·
`work access. To setup (3) is to establish such a connection
`tear-off menu
`In a GUI , a menu which can be moved, an::
`possibly resized. Used, fo r instance, for optimal positionin:i'
`of tools when switc hing frequent ly between a tool palette
`and an image being edited. Also spelled tearoff menu .
`tearing In TV , a forrn of distortion in which groups of hori·
`zontal lines are displaced in an irregular manner, resembl ing
`the ripping of a fab ric. It is caused by improper horizontal
`sync .
`tearoff menu Same as tear-off menu .
`tebi- A binary prefix meaning 2'0
`, or 1,099,5 I 1,627,776. For
`example, a teb ibyte is equal to 240
`, or 1,099,5 I I ,627,776
`bytes. This prefix is utilized to refer to only binary quanti(cid:173)
`ties, such bits and bytes Its abbreviation is Ti-.
`tebibyte 2' 0
`, or 1,099,511 ,627,776 bytes.
`Its abbrev iation is
`TiB .
`tech support Abbreviation of technical support.
`technetium A silver-gray radioactive metal whose atomic
`number is 43 . It has close to 30 known isotopes, all unsta(cid:173)
`ble, and is used in nu clear medicine, tracer studi es, lasers,
`and superconductors. Its chemical sy mbol is Tc.
`technical support The technical he lp a provider of hardware,
`software, network services, or the like, is supposed to pro(cid:173)
`vide to customers. Its abbre viation is tech support.
`technobabble Terminology which is speciali zed to a given
`fie ld, such as computers or communications, and which is
`usuall y not understood by those not suffi ciently familiar
`with said field. Such terrns are often utilized improperly to
`confuse, intimidate, marginalize, or oth erwise make a person
`uncomfortable.
`technological Pertaining to, incorporating, affected by, or
`arisi ng from technology.
`technology 1. The app lication of science, engi neering, and
`other areas of expertise to the creatio n and improvement of
`that whi ch is utilized for commerce and/or industry. 2. A
`specific technological method , techn iq ue, use, or approach
`
`