Infovary

DIGITAL ELECTRONICS AND MICROPROCESSOR

PART 1

ac.

 Abbreviation alternating current.

active device.

One that can control voltage or current. Examples are the Transistor amplifier and the diode rectifier.

A/D converter.

A device that converts analog input signals to digital output.

admittance (Y).

Reciprocal of impedance Z in ac circuits. Y= 1/Z.

air gap.

Air space between poles of a magnet.

algorithm.

The sequence of operations ub digital computations.

alkaline cell or battery.

One that uses alkaline electrolyte.

alpha (a).

Characteristics of junction transistors. Ratio if collector current to

emitter current. Value is 0.98 to 0.99.

Alligator clip.

spring clip for temporary wire connection.

 alternating current (ac).

The current that reverses direction at a regular rate. Alternating voltage

reverses in polarity. The rate of reverses is the frequency.

alternating.

AC generator.

ampere (A).

The basic unit of electric current. The value of one ampere flows when one

volt of potential difference is applied across one ohm of resistance.

ampere-turn.

Unit of magnetizing force equal to 1 Ax 1 turn.

amplifier.

A device that increases the amplitude of a signal.

amplitude modulation.

RF carrier wave in step with a lower-frequency signal that has the

desired information.

analog circuits.

Circuits that use continuous variations in voltage are Current,

compared with digital pulse circuits.

AND gate.

The digital logic circuit produces High output of 1only when all inputs are

at 1.

antiresonance.

 alternating current (ac).

The current that reverses direction at a regular rate. Alternating voltage

reverses in polarity. The rate of reverses is the frequency.

alternating.

AC generator.

ampere (A).

The basic unit of electric current. The value of one ampere flows when one

volt of potential difference is applied across one ohm of resistance.

ampere-turn.

Unit of magnetizing force equal to 1 Ax 1 turn.

amplifier.

A device that increases the amplitude of a signal.

amplitude modulation.

RF carrier wave in step with a lower-frequency signal that has the

desired information.

analog circuits.

Circuits that use continuous variations in voltage are Current,

compared with digital pulse circuits.

AND gate.

The digital logic circuit produces High output of 1only when all inputs are

at 1.

 antiresonance.

A term sometimes used for parallel resonance

apparent power.

Product of Vx 1 when they are out of phase. Measured in volt-ampere

units, instead of watts

armature.

The part of a generator in which the voltage is Also, the moveable part

of a relay.

astable MV.

Multivibrator that has no stable state. Used as an oscillator to

generate clock timing pulses.

audio frequency (AF).

Within the range of hearing, approximately 16 to 16,000 Hz

autotransformer.

A signal, tapped, winding used to step up or step down voltage

average value.

In sine-wave ac voltage or current, is 0.637 of the peak value

back-off scale.

Ohmmeter readings from right to left.

bandpass.

Filter that allows a band of frequencies to be coupled to the load.

band-stop.

Filter that prevents band of frequencies from being coupled to the load.

 bandwidth. 

A range of frequencies that have a resonant effect in LC circuits. 

bank.

Components are connected in parallel battery groups of cells connected in series of parallel.

 BCD.

Binary coded decimal. Converts a decimal number to a binary equivalent.

 beta(B). 

Current-gain characteristic of junction transistors. the ratio of collector current to base current.

 bias.

The average dc level of amplifier voltage or current to set operating characteristic. 

binary number system.

A system that uses only two digits, 0 and 1.

bipolar transistor.

NPN or PNP type.

bistable Mv

Multivibrator that has to stable states. Used as flip-flop circuit.

bit.

One unit of information, either 0 or 1, in the binary number system.

bleeder current.

Steady current from the source used to stabilize output voltage with

changes in load current.

Boolean algebra.

The logical system of using binary information in digital circuits.

branch.

Part of a parallel circuit

bridge.

The circuit in which voltages or currents can be balanced for a net effect

of zero.

brushes.

In a motor are generators, devices that provide stationary connections

to the rotor.

bypass capacitor.

One that has very low reactance in a parallel path.

byte.

Digital word with a string of eight bits of 0 and 1.

C

Symbol for capacitance

Abbreviation for coulomb, the unit of electric charge.

calorie.

Amount of heat energy needed to raise the temperature of one gram

of water by 10C.

capacitor.

A device used to store an electric charge.

capacitance.

The ability to store an electric charge.

carry-in.

Number added from the previous lower-order column also.

carry-out.

Number added to the next higher-order column also. Carry is

necessary when the sum in a column is more than the radix of the number

system.

cascaded amplifiers.

The output terminal of one stage drives the input terminal of the next stage.

CB circuit.

Common-base amplifier for junction transistor. Signal into emitter and

the output from the collector.

CB radio.

Gitinem’s band radio, 26.965 to 27.405 MHZ.

CB circuit.

Common-collector amp

amplifier for junction transistor. Signal into base

and output from the emitter. Is the emitter follower stage.

CD circuit.

Common-drain circuit for the field-effect transistor. Is source-follower

stage

CE circuit.

Common-emitter amplifier for junction transistors. Signal into base

the output from the collector.

Celsius scale (oC).

Temperature scale that uses 0o for the freezing point of water and

1000 for the boiling point. Formerly called centigrade.

ceramic.

Insulator with a high dielectric constant, of the used for capacitors

chassis ground.

Common return for all electronic circuits mounted on one metal

chassis or PČ board. Usually connects to one side of dc supply voltage

CG circuit.

Common-gate amplifier for field-effect transistors.

CGS.

Centimeter-gram-second system of units.

chip.

Miniature semiconductor for integrated circuit

choke.

Inductance with high XL compared with the R.of the circuit.

circuit breaker.

A protective device that opens then excessive current fio

Circuit

Can be rest.

circuit mil.

The cross-sectional area of round wire with a diameter of 1 mil or 0.001 in

clamp probe.

A device is used to measure current without opening the circuit.

clear.

Same as reset on a flip-flop. Pits Q output at logic 0.

clock.

A device that provides timing pulses for digital circuits; it is usually a

multivibrator (MV) oscillator.

closed circuit.

A continuous path for current.

Complementary metal-oxide-semiconductor. Uses both, P-type

CMOS.

An inner conductor surrounded by an outer conductor that sei

N-type channels.

Coaxial cable.

that serves as a shield Coil

Turns of wire conductor to concentrate the magnetic field.

color code.

The system in which colors are used to indicate values in resistors and

capacitors.

commutator.

A device that converts reversing polarities to one polarity.

complex number.

One that has real and j items. Uses the from A + jB.

conductance (G).

Ability to conduct current. It is the reciprocal of resistance, G = 1/R.

The unit of conductances is the siemens (S)

constant-current source.

One that has ri to supply constant I with variations in RL.

constant voltage source.

One that has lowri to supply constant V with variations in RL

continuity.

The continuous path for current. Reading of zero ohms with an ohmmeter

conventional current.

The direction of flow of positive charges, opposite form electron THOW

Corona.

Effect of ionization of air around a point at high potential.

Cosine.

A trigonometric function of an angle equal to the ratio of the adjacent

side to the hypotenuse in a right triangle.

cosine wave.

One whose amplifier varies as the cosine function of an angle. It is 90

out of phase with the sine wave.

coulomb (C).

Unit of electric charge. 1 C = 6.25x 1018 electrons.

counter.

Digital circuit using a flip-flop to accumulate the count of pulses.

coupling capacitor.

Has very low Xc in the series path.

covalent bond.

The pairing of atoms with an electrical valence of +4.

cps.

cycles per second. Formerly used as a unit of frequency. Replace oy

hertz (Hz) unit were 1 Hz = 1 cps.

CRT.

al

n0de-ray tube. A device that converts electric signal

displays on a fluorescent screen.

CS circuit.

Common-source amplifier for the field-effect transistor.

Current divider.

A parallel circuit to provide branch I less than the main-line current.

current source.

supplies = Vin to load, with r in the parallel

cutoff.

No current in an active device such as a transistor.

cycle.

One complete set of values for a repetitive waveform.

DIA converter.

A device that converts digital input to analog output.

damping

Reducing the Q of a resonant circuit to increase the bandwidth.

Darlington pair.

Combination of two transistor stages in cascade.

D’ Arsonval meter.

A dc analog meter movement is commonly used in ammeters and

voltmeters.

data selector.

Digital circuit to convert parallel data to serial data. Also called

a multiplexer.

dB.

Abbreviation

**deviation for decibel. Equals 10 times the logarithm of the ratio of

two power levels.

dc.

Abbreviation for direct current.

degaussing.

Demagnetizing by applying an ac filed and gradually reducing it

to zero.

delta (A) network.

Three components are connected in series in a closed loop. Same as pi

(T) network.

demultiplexer.

Digital circuit to convert serial data to parallel data. Also called

distributor or decoder.

detector diode.

A device that rectifies a modulated signal to recover information in u

modulation.

diac.

A two-terminal semiconductor device is used for trigger pulses.

diamagnetic.

Material that can be weakly magnetized in the opposite

direction from the magnetic field.

dicing.

Cutting a slice of semiconductor material into tiny chips.

dielectric.

insulating material. It cannot conduct current but does store charge

dielectric constant (k).

Ability to concentrate the electric field in a dielectric

differentiating circuit.

An RC circuit with a short time constant for pulses across R.

digital circuit.

One that uses only two amplitudes for a pulse of voltage or current,

either HIGH at 1 or Low at 0.

digital IC.

Abbreviation for a digital integrated circuit.

diode.

Electronic device with two electrodes. Allows current flow in only one

direction.

DIP.

Dual inline package for the pins of IC chip.

direct current (dc).

Current that flows in the only direction. Dc Voltage has a steady polarity that does not reverse.

discrete component.

A signal individually packaged component usually with two or three

leads.

distributor.

Digital circuit to convert serial data to parallel data. Also called

demultiplexer.

DMM.

Abbreviation for a digital multimeter.

doping.

Adding impurities to the pure semiconductor material to provide free, positive, and negative charges.

double subscripts.

An example of us to indicate voltage at point B concerning point A.

DPDT.

Double-pole double-throw switch or relay contacts.

DPST.

Double-pole signal-throw switch or relay contacts.

dynamometer.

Type of ac meter, generally for 60Hz.

ECL.

Emitter-coupled logic circuits.

eddy current.

Circulating current induced in the iron core of ab inductor by ac

variations of magnetic flux.

effective value.

For sine-wave ac waveform, 0.707 of the peak value. Corresponds to

the heating effect of the same dc value. Also called RMS value.

efficiency.

The ratio of power output to the power input of 100%.

EIA.

Electronic Industries Association.

electricity.

Dynamic electricity is the effect of voltage in producing current in

conductors. Static electricity is an accumulation of charge.

electrolyte.

Solutions from ion charges

electrolytic capacitor.

Type with very high C because the electrolyte is used to form a very thin

dielectric. Must be connected with correct polarity in a circuit.

electromagnet.

Magnet whose magnetic field is associated with an electric current in a

Coil.

electron.

Basic particles of negative charges, in orbital rings around the nucleus

in an atom.

electron flow.

The current of negative charges in motion. The direction is from the negative

terminal of the voltage source, through the external circuit, and returning

the positive side of the source. Opposite to the direction of conventional current.

electron volt.

Unit of energy equal to the work done in moving a charge of an electron

through a potential difference of 1volt.

electronics.

Based on the electrical effects of the electron, Includes an application for

amplifiers, Oscillators, rectifiers control circuits, and digital pulse circuit.

E.M.F.(Electromotive force)

voltage produces a current in a circuit.

emitter follower

The circuit in which signal input into base and output is from the emitter

Same as common -collector circuit

EPROM.

Erasable programmable ROM device.

F connector.

Solderless plug for coaxial cable.

Fahrenheit scale.

Temperature scale that uses 32o for the freezing point water and 212o

for the boiling point.

fane-in.

A maximum number of input circuits for the logic gate.

fan-out.

For a logic gate maximum number of output circuits that can be used

as a load.

farad (F).

Unit of capacitance.Value of one-farad store one coulomb of charge

with one volt applied.

Faraday’s law.

For magnetic induction, the generated voltage is proportional to the

flux and its rate of change.

FCC.

Federal Communication Commission.

Farris.

Magnetic material properties of iron and other metals that can be

strongly magnetized in the same direction as the magnetizing field.

FET.

field-effect transistor.

field.

Group of the line of force.Can be a magnetic or an electric field.

field-effect transistor. (FET).

A device that depends on an electric field to control the current in a silicon channel.

field winding.

The part of the motor or generator that supplies the magnetic field is cut by

the armature.

filter.

Circuit to separate different frequencies.

fluctuating dc.

Varying volt and current but no change in polarity.

flux.

Magnetic line of force.

flux density.

Amount of flux per unit area.

flywheel effect.

The ability of an LC circuit to continue oscillating after the energy source

has been removing.

forward voltage.

the polarity that allows the current majority carries through a semiconductor

junction.

frequency.

several cycles per second for a waveform with periodic variations.

The unit of frequency is hertz (HZ).

frequency modulation (FM).

 

 

 

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