ñòð. 42 |

B

zero voltage coefficient A voltage coefficient hav-

VTVM ing the value of zero (i.e., one that indicates there

circuit is no voltage-dependent drift of a given quantity).

zero-zero The atmospheric condition in which the

ceiling and visibility both are zero (i.e., extremely

dense fog).

zero set, 2

770 Z gain â€¢ Z meter

Z gain The gain (or gain control) of the intensity zinc cadmium sulfide phosphor Either of two

channel of an oscilloscope. Compare X GAIN and similar substances used as a phosphor coating

Y GAIN. for cathode-ray-tube screens. One form glows

zig The short, straight deflection of a point or par- blue; the other form glows red.

ticle, or of a wave along a jagged path in a direc- zincâ€“carbon cell A common non-rechargeable

tion opposite that of ZAG; a component of electrochemical cell. Produces approximately

ZIGZAG DEFLECTION. 1.5 volts under no-load conditions. Zinc forms

zigzag deflection Deflection of a particle, point, or the outer case or shell, and is the negative elec-

object in a path that contains side-to-side mo- trode. A carbon rod serves as the positive elec-

tion, as well as forward motion. Also see ZAG and trode. The electrolyte is a paste of manganese

ZIG. dioxide and carbon. The cell is inexpensive, and

zigzag rectifier A special version of the three- is commercially available in various sizes. The

phase star (three-phase, half-wave) rectifier cir- shelf life is fairly long. Cells of this type work well

cuit. Direct-current (dc) saturation of the at moderate temperatures, and in applications

transformer secondary is avoided by winding half where the current drain is moderate to high.

the turns of each secondary on a separate core They function poorly at low temperatures. Com-

(i.e., each core carries two half-windings). The op- pare ALKALINE CELL.

posing flux resulting from different phases in the zinc germanate phosphor A substance used as a

half-windings causes cancellation of the dc com- phosphor coating for cathode-ray-tube screens. It

ponent of flux in each core. glows yellow-green.

zigzag reflections Multihop reflections of waves zinc magnesium fluoride phosphor A substance

along a zigzag path, resulting from repeated re- used as a phosphor coating for cathode-ray-tube

flections within the ionosphere. screens. It glows orange.

zinc Symbol, Zn. A metallic element. Atomic num- zincolysis Electrolysis in a cell having a zinc

ber, 30. Atomic weight, 65.39. It is used as the anode.

negative-electrode material in dry cells and as a zinc orthoscilicate phosphor Also called Willemite.

protective coating for some metals used in elec- A substance used as a phosphor coating for

tronics. cathode-ray-tube screens. It glows yellow-green.

zinc oxide A substance used as a phosphor coat-

ing for cathode-ray-tube screens. It glows blue-

green. It is also used in the manufacture of

certain electronic components, such as resistors.

+

F zinc-oxide resistor A voltage-dependent resistor

dc Output whose active ingredient is zinc oxide.

_

B

A zinc silicate phosphor A substance used as a

E phosphor coating for cathode-ray-tube screens. It

Three-

glows blue.

phase

zinc standard cell A standard cell using zinc and

input

mercury electrodes, and a mercurous sulfate ex-

C citant and depolarizer. Produces 1.4322 volts at

15Â°C. Also called Clark cell. Compare WESTON

CELL.

D

zinc sulfide phosphor A substance used as a

phosphor coating for cathode-ray-tube screens.

Glows blue-green or yellow-green.

ZIP Abbreviation of zinc-impurity photodetector.

zigzag rectifier zip cord A simple two-conductor, flexible power

cord.

zirconia Preparations of zirconium (especially

zinc aluminate phosphor Either of two similar

Zr02), valued for their high-temperature dielectric

substances used as a phosphor coating for

properties.

cathode-ray tube screens. One form glows blue;

zirconium Symbol, Zr. A metallic element. Atomic

the other form glows red.

number, 40. Atomic weight, 91.22.

zinc beryllium silicate phosphor A substance

Z marker A vertically radiating marker beacon

used as a phosphor coating for cathode-ray-tube

defining the zone above a radio-range station.

screens. It glows yellow.

Z meter A device for measuring impedances. In-

zinc beryllium zirconium silicate phosphor A

struments of this kind take four principal forms:

substance used as a phosphor coating for cath-

(1) a direct-reading meter resembling an ohmme-

ode-ray-tube screens. It glows white.

ter; (2) an adjustable circuit manipulated some-

zinc borate phosphor A substance used as a

what like a bridge and that compares an

phosphor coating for cathode-ray-tube screens. It

unknown impedance with a standard resistance;

glows yellow-orange.

771

Z meter â€¢ zwitterion

(3) an impedance bridge for evaluating the reac- which a molten zone in an ingot of the material

tive and resistive components of an unknown moves along the length of the ingot, dissolving

impedance; (4) a section of transmission line impurities as it travels, eventually depositing

used with a signal source and voltmeter for mea- them at the end of the ingot, which is sawed off.

suring impedance in terms of a standard resistor This concentrated and segregated melting is ac-

and/or standing waves. complished by means of radio-frequency heating.

ZMODEM In data communications, an error-cor- zone time In a given time zone, standard time in

rection mode similar to XMODEM, except that terms of the number of hours that must be added

when an error is found during transmission of a to local time to equal the time at the zero (Green-

block of data, the source retransmits only that wich) meridian.

portion of the block following the error. This im- zoning 1. A method of fabricating a microwave

proves data transmission speed because, when reflector in concentric, flat regions, producing

an error occurs, the number of bytes retransmit- the same practical results as a continuous

ted is generally fewer than the 128K block size paraboloid. 2. In a communications system, the

standard in XMODEM. Compare XMODEM and division of the coverage area into different geo-

YMODEM. graphic regions for a specific purpose.

Zn 1. Symbol for ZINC. 2. Symbol for AZIMUTH. zoom 1. To rapidly change the focal length of a

Z0 Symbol for CHARACTERISTIC IMPEDANCE. television or motion-picture camera lens so that

zone 1. On a magnetic disk, a group of tracks the object seems to advance toward or recede

whose associated transfer rate is not the same as from the viewer, remaining in focus as it does so.

that for the rest of the disk. 2. In computer oper- 2. See ZOOM LENS. 3. To magnify the image in a

ations, the area of a storage medium containing computer graphical user interface. A user can en-

digits. 3. In a computer system, a main memory large a specific portion of the display, at the ex-

area set aside for a particular purpose. 4. In a se- pense of other portions. It is generally measured

curity system, a specified area or region under in percent (e.g., 200% zoom represents a magnifi-

surveillance. cation factor of 2).

zone blanking In a radar system, a method of ex- zoom lens A continuously adjustable lens system

tinguishing the cathode-ray-tube beam during a that allows zoom effects to be obtained with a

portion of the antenna sweep. television or motion-picture camera, or a similar

zone candle power In a given zone, the luminous arrangement for still cameras that obviates the

flux per steradian, emitted by a light source un- need for lens interchange when different focal

der test. lengths are needed. The lens system, which can

zoned circuit In a security system, a circuit in be operated electronically, allows either narrow-

which some areas are protected at all times, while or wide-angle views to be obtained without losing

the protection in other areas can be temporarily focus at any time.

disabled for entry or exit. Z parameters Device or network parameters ex-

zone leveling See ZONE REFINING. pressed as impedances.

zone marker See Z MARKER. ZPI Abbreviation of ZONE-POSITION INDICATOR.

zone melting See ZONE REFINING. Z-plunger In a waveguide, a combination choke

zone of silence The region between alternate re- and bucket plunger for radiation leakage reduc-

flections of a radio wave, in which no signal is de- tion.

tectable. Also called skip zone. Zr Symbol for ZIRCONIUM.

zone plate antenna A rapid-scan radar antenna Z signals A collection of letter groups, each starting

having a reflector composed of confocal parabolas with the letter Z, used for simplified telegraphy

arranged in a circle. and radiotelegraphy by the military services.

zone-position indicator A radar that reveals the Zulu Phonetic alphabet communications code

position of an object to a second radar having a word for the letter Z.

restricted field. Zulu time Greenwich mean time. Also see ZEBRA

zone purification See ZONE REFINING. TIME.

zone refining A method of purifying semiconduc- zwitterion An ion that carries both a positive and

tor materials (such as germanium and silicon) in a negative charge.

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Appendix A

Schematic symbols

^

Ammeter

Amplifier general

Amplifier, inverting

Amplifier, operational

AND gate

Antenna, balanced

Antenna, general

Antenna, loop

Antenna, loop, multiturn

âˆ’ +

Battery

Capacitor, feedthrough

Capacitor, fixed

Capacitor, variable

Capacitor, variable, split-rotor

Capacitor, variable, split-stator

Copyright Â© 2001 by The McGraw-Hill Companies, Inc.

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774 Appendix A

Cathode, electron-tube, cold

Cathode, electron-tube, directly heated

Cathode, electron-tube indirectly heated

Cavity resonator

âˆ’ +

Cell, electrochemical

Circuit breaker

Coaxial cable

Crystal, piezoelectric

Delay line

Diac

Diode, field-effect

Diode, general

Diode, Gunn

Diode, light-emitting

Diode, photosensitive

775

Schematic symbols

Diode, PIN

Diode, Schottky

Diode, tunnel

Diode, varactor

Diode, zener

Directional coupler

W

Directional wattmeter

Exclusive-OR gate

Female contact, general

Ferrite bead

Filament, electron-tube

Fuse

G

Galvanometer

Grid, electron-tube

Ground, chassis

776 Appendix A

Ground, earth

Headset

Handset, double

Headset, single

Y

FL

R

L

Headset, stereo AM

Inductor, air core

Inductor, air core, bifilar

TE

Inductor, air core, tapped

Inductor, air core, variable

Inductor, iron core

Inductor, iron core, bifilar

Inductor, iron core, tapped

Inductor iron core, variable

Inductor, powdered-iron core

Inductor, powdered-iron core, bifilar

Team-FlyÂ®

777

Schematic symbols

Inductor, powdered-iron core, tapped

Inductor, powdered-iron core, variable or

Integrated circuit, general (Design-show)

Jack, coaxial or phono

Jack, phone, two-conductor

Jack, phone, three-conductor

Key, telegraph

Lamp, incandescent

Lamp, neon

Male contact, general

Meter, general

ÂµA

Microammeter

Microphone

778 Appendix A

Microphone, directional

mA

Milliammeter

NAND gate

âˆ’

Negative voltage connection

NOR gate

NOT gate

Optoisolator

OR gate

Outlet, two-wire, nonpolarized

Outlet, two-wire, polarized

Outlet, three-wire

Outlet, 234-V

Plate, electron-tube

Plug, two-wire, nonpolarized

779

Schematic symbols

Plug, two-wire, polarized

Plug, three-wire

Plug, 234-V

Plug, coaxial or phono

Plug, phone, two-conductor

Plug, phone, three-conductor

+

Positive voltage connection

Potentiometer

or

Probe, radio-frequency

Rectifier, gas-filled

Rectifier, high-vacuum

Rectifier, semiconductor

Rectifier, silicon-controlled

780 Appendix A

Relay, double-pole, double-throw

Relay, double-pole, single-throw

Relay, single-pole, double-throw

Relay, single-pole, single-throw

Resistor, fixed

Resistor, preset

Resistor, tapped

Resonator

Rheostat

Saturable reactor

Signal generator

Solar battery

âˆ’ +

781

Schematic symbols

Solar cell

âˆ’ +

Source, constant-current

+ âˆ’

Source, constant-voltage

Speaker

Switch, double-pole, double-throw

Switch, double-pole, rotary

Switch, double-pole, single-throw

Switch, momentary-contact

Switch, silicon-controlled

Switch, single-pole, rotary

Switch, single-pole, double-throw

Switch, single-pole, single-throw

782 Appendix A

Terminals, general, balanced

Terminals, general, unbalanced

Test point TP

Thermocouple or

Transformer, air core

Transformer, air core, step-down

Transformer, air core, step-up

Transformer, air core, tapped primary

Transformer, air core, tapped secondary

Transformer, iron core

Transformer, iron core, step-down

Transformer, iron core, step-up

Transformer, iron core, tapped primary

Transformer, iron core, tapped secondary

783

Schematic symbols

Transformer, powdered-iron core

Transformer, powdered-iron core, step-down

Transformer, powdered-iron core, step-up

Transformer, powdered-iron core, tapped primary

Transformer, powdered-iron core,

tapped secondary

Transistor, bipolar, NPN

Transistor, bipolar, PNP

Transistor, field-effect, N-channel

Transistor, field-effect, P-channel

Transistor, MOS field-effect, N-channel

Transistor, MOS field-effect, P-channel

Transistor, photosensitive, NPN

Transistor, photosensitive, PNP

784 Appendix A

Transistor, photosensitive, field-effect,

N-channel

Transistor, photosensitive, field-effect,

P-channel

Transistor, unijunction

Triac

Tube, diode

Tube, heptode

Tube, hexode

Tube, pentode

Tube, photosensitive

Tube, tetrode

785

Schematic symbols

Tube, triode

V

Voltmeter

W

Wattmeter

Waveguide, circular

Waveguide, flexible

Waveguide, rectangular

Waveguide, twisted

(preffered)

Wires, crossing, connected or

(alternative)

(preffered)

Wires, crossing, not connected or

(alternative)

Y

FL

AM

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TE

Team-FlyÂ®

Appendix B

Tables and data

Conversion between Electrical Systems

System

cgs cgs

Property mks electromagnetic electrostatic

9

1011 statfarad

Capacitance 1 farad 10 abfarad 9

109 F 1020 statF

1 abF 9

11 20

10 /9 F 10 /9 abF 1 statF

109 statC

Charge 1 coulomb 0.1 abcoulomb 3

1010 statC

10 C 1 abC 3

10 9/3 C 10

10 /3aC 1 statC

1 coulomb/m3 7

abcoulomb/cm3 103 statcoulomb/cm3

Charge density 10 3

107 C/m3 1 abC/cm3 1010 statCcm3

3

10 3/3 C/m3 10

/3 aC/cm3 1 statC/cm3

10

11

109 statSiemens/cm

Conductivity 1 siemens/m 10 absiemens/cm 9

1011 S/m 1020 statS/cm

1 abS/cm 9

10 9/9 S/m 20

10 /9 abS/cm 1 statS/cm

1

109 statampere

Current 1 ampere 10 abampere 3

1010 statA

10 a 1 abA 3

10 9/3 a 10

10 /3 abA 1 statA

1 ampere/m2 5

abampere/cm2 105 statampere/cm2

Current density 10 3

105 A/m2 1 abA/cm2 1010 statA/cm2

3

10 5/3 A/m2 10

/3 aA/cm2 1 statA/cm2

10

106 abvolt/cm 10 4/3 statvolt/cm

Electric field intensity 1 volt/m

6 10

10 V/m 1 abV/cm 10 /3 statV/cm

104 V/m 1010 aV/cm

3 3 1 statV/cm

108 abvolt 10 2/3 statvolt

Electric potential 1 volt

8 10

10 V 1 abV 10 /3 statV

102 V 1010 aV

3 3 1 statV

1011 statC-cm

Electric dipole moment 1 coulomb-m 10 abC-cm 3

1010 statC-cm

0.1 C-m 1 abC-cm 3

11 10

10 /3 C-m 10 /3 abC-cm 1 statC-cm

Copyright Â© 2001 by The McGraw-Hill Companies, Inc.

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788 Appendix B

System

cgs cgs

Property mks electromagnetic electrostatic

107 erg 107 erg

Energy 1 joule

7

10 J 1e 1e

7

10 J 1e 1e

105 dyne 105 dyne

Force 1 newton

5

10 N 1d 1d

5

10 N 1d 1d

1 Weber/m2 104 gauss (or abtesla) 10 6/3 electrostatic unit

Flux density

4

Wb/m2 10

10 1G 10 /3 esu

6 2 10

3 10 Wb/m 3 10 G 1 esu

109 abhenry 11

Inductance 1 henry 10 /9 stathenry

9 20

10 H 1 abH 10 /9 statH

11 20

9 10 H 9 10 abH 1 statH

11

109 statfarad/cm

Inductive capacity 1 farad/m 10 abfarad/cm 9

1011 F/m 1020 statF/cm

1 abF/cm 9

10 9/9 F/m 20

10 /9 abF/cm 1 statF/cm

108 Maxwell 10 2/3 electrostatic unit

Magnetic flux 1 weber

8 10

10 W 1 Mx 10 /3 esu

2 10

3 10 W 3 10 Mx 1 esu

1 ampere-m2 103 abampere-cm2 1013 statampere-cm2

Magnetic dipole moment 3

3

A-m2 1 abA-cm2 1010 statA-cm2

10 3

13

/3 A-m2 10

/3 abA-cm2 1 statA-cm2

10 10

107 abhenry/cm 13

Permeability 1 henry/m 10 /9 stathenry/cm

7 20

10 H/m 1 abH/cm 10 /9 statH/cm

1013 H/m 1020 abH/cm

9 9 1 statH/cm

107 erg/s 107 erg/s

Power 1 watt

7

10 W 1 e/s 1e/s

7

10 W 1 e/s 1e/s

109 abohm 11

Resistance 1 ohm 10 /9 statohm

9 20

10 ohm 1 abohm 10 /9 statohm

11 20

9 10 ohm 9 10 abohm 1 statohm

789

Tables and data

GREEK ALPHABET

Capital Lowercase Name

Î±

A alpha

Î²

B beta

Î³ gamma

Î´ or âˆ‚

âˆ† delta

Îµ

E epsilon

Î¶

Z zeta

Î·

H eta

Î¸ or

Î˜ theta

I iota

K kappa

lambda

M mu

N nu

xi

O omicron

pi

P rho

or sigma

T tau

Ï… upsilon

or phi

chi

psi

omega

Mathematical Functions

Signs and symbols

â‰

radix (base) point not equal to

âˆ¼

â€¢ multiplication symbol; logic AND function similar to

infinity less than

plus; positive; logic OR function not less than

minus; negative much less than

plus or minus; positive or negative greater than

minus or plus; negative or positive not greater than

times much greater than

â‰¤

divided by equal to or less than

â‰¥

divided by (expressive of a ratio) equal to or greater than

equal to proportional to; varies directly as

or â†’

identical to; is defined by approaches

or approximately equal to, congruent to is to; proportional to

approximately equal to therefore

790 Appendix B

@ at the rate of; at cost of x average value of x; x not

e natural number = 2.71828 f(x) or F(x) function of x

pi 3.14159 . . . i 1

() parentheses (use to enclose a group of terms)

[] brackets (use to enclose a group of terms that j operator, equal to 1

âˆ†x

includes one or more groups in parentheses) increment of x

{} braces (use to enclose a group of terms that

includes one or more groups in brackets. dx differential of x

âˆ âˆ‚x

angle partial differential of x

Â° degrees (arc or temperature)

âˆ†x

â€² minutes; prime change in x with respect to y

âˆ†y

â€²â€² seconds; double prime

dx

ï£ºï£º parallel to derivative of x with respect to y

dy

âŠ¥ perpendicular to

d

... and beyond (x) derivative of x with respect to y

dy

(del or nabla) vector differential operator dyx derivative of x with respect to y

âˆ‚x

partial derivative of x with respect to y

âˆ‚y

Operations

x y x added to y; x OR y summation

a

x y y subtracted from x summation between limits (from a to b)

b

x y, x y, multiplied by y; x AND y

Î

or xy product

a

Î

x y x divided by y product between limits (from a to b )

b

x

x/y or x divided by y integral

y

b

1/x reciprocal of x integral between limits (from a to b)

a

xn x raised to the indicated power of n x dy integral of x with respect to y

n

x indicated root n of x |a evaluated at a

|b

x:y x is to y evaluated between limits (from a to b)

a

|x| absolute value of x, magnitude of x n! factorial of n

X, X, or X vector X

791

Tables and data

Prefixes

Prefix Quantity Symbol

10 18

atto- a

10 15

femto- f

10 12

pico- p

10 9

nano- n

10 6

micro-

10 3

milli- m

10 2

centi- c

10 1

deci- d

deka- 10 da

102

hecto- h

103

kilo- k

106

mega- M

109

giga- G

1012

tera- T

1015

peta- P

1018

exa- E

RESISTOR COLOR CODE

The first three color bands supply the total resistance. The fourth color (if any ) gives the tolerance. Example: A

5,600-ohm resistor would have green (first color, 5), blue (second color, 6) and red

1 2 3 4 body

1 2 3 4

black = 0 black = 0 black = gold 5%

brown = 1 brown = 1 brown = 0 silver 10%

red = 2 red = 2 red = 00 no band 20%

orange = 3 orange = 3 orange = 000

yellow = 4 yellow = 4 yellow = 0000

green = 5 green = 5 green = 00000

blue = 6 blue = 6 blue = 000000

violet = 7 violet = 7 gold = multiply by 0.1

gray = 8 gray = 8 silver = multiply by 0.01

white = 9 white = 9

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Suggested additional

references

Crowhurst, N. and Gibilisco, S., Mastering Technical Mathematicsâ€”2nd Edition. New York: McGraw-Hill,

1999.

Dorf, R., Electrical Engineering Handbookâ€”2nd Edition. Boca Raton, FL: CRC Press, 1997.

Gibilisco, S., Electronics Portable Handbook. New York: McGraw-Hill, 1999.

Gibilisco, S., Electronics Formulas Pocket Reference. New York: McGraw-Hill, 1999

Gibilisco, S., Mathematical and Physical Data, Equations, and Rules of Thumb. New York: McGraw-Hill,

2001.

Van Valkenburg, M., Reference Data for Engineers: Radio, Electronics, Computer and Communications.

Indianapolis: Howard W. Sams & Co., 1998.

Veley, V., The Benchtop Electronics Reference Manual. New York: McGraw-Hill, 1994.

Copyright Â© 2001 by The McGraw-Hill Companies, Inc.

Click here for Terms of Use.

This page intentionally left blank

About the author

Stan Gibilisco has authored or coauthored dozens of nonfiction books

about electronics and science. He first attracted attention with Under-

standing Einsteinâ€™s Theories of Relativity (TAB Books, 1983). His Encyclo-

pedia of Electronics (TAB Professional and Reference Books, 1985) and

Encyclopedia of Personal Computing (McGraw-Hill, 1996) were annotated

by the American Library Association as among the best reference volumes

published in those years. Stanâ€™s work has gained reading audiences in the

Far East, Europe, and South America.

Copyright Â© 2001 by The McGraw-Hill Companies, Inc.

Click here for Terms of Use.

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