# Analogue vs digital

 Date conversion 13.06.2017 Size 32.96 Kb.
ANALOGUE VS DIGITAL
Analogue describes a device or system that represents changing values as continuously variable physical quantities. It is a machine or electronic circuit designed to work on numerical data represented by some physical quantity (e.g. rotation or displacement) or electrical quantity (e.g. voltage or charge), which varies continuously.

For example, the turning of the wheel or changes in voltage can be used as input. Analogue computers are said to operate in real time and are used for research in design where many different shapes and speeds can be tried quickly. A computer model of a car suspension allows the designer to use the effects of changing size, stiffness and damping.

A typical analogue device is a clock in which the hands move continuously around the face. Such a click is capable of indicating every possible time of day. In contrast a typical clock is capable of representing only a finite number of times (every tenth of a second, for example_/ In general, humans experience the world analogically. Vision for example is an analogical because we perceive infinitely smooth gradations of shapes and colours. Most analogue events, however, can be stimulated digitally. Photographs in newspapers, for instance, consist of an array of dots that are either black or white. From afar, the viewer does not see the dots (the digital form), but only lines and shading, which appear to be continuous. Although Digital representations are approximations of analogue events, they are useful because they are easy to store and manipulate electronically.

When used in reference to data storage and transmission, analogue format is that in which information is transmitted by modulating a continuous transmission signal, such as amplifying a signal’s strength or varying its frequency to add or take away data. For example, telephones take sound vibrations and turn them into electrical vibrations of the same shape before they are transmitted over traditional telephone lines. Radio wave transmissions work in the same way. Computers, which handle data in digital form, require modems to turn signals from digital to analogue before transmitting those signals over communication lines such as telephone lines that carry only analogue format. The trick is in converting from analogue to digital, and back again.

This is the principle behind compact discs (CDs). The music itself exists in an analogue form, as waves in the air, but these sounds are then translated into a digital form that is encoded onto the disk. When you play a compact disc, the CD player reads the digital data, translates it back into its analogue form, and sends it to the amplifier and eventually the speakers.

The term digital describes any system based on discontinuous data or events. A digital device processes numerical information and pore generally manipulates symbolic information, according to specified computational procedures. The digital computer – embraces calculators, computer work stations, control computers (controllers) for applications such as domestic appliances and industrial processes, data processing systems, microcomputers, microcontrollers, multiprocessors, parallel computers, personal computers, network servers, and supercomputers.

A digital computer is an electronic computing machine that uses the binary digits. It can distinguish between just two values, 0 and 1, or on and off. There is no simple way to represent all the values in between, such as 0,25.All data that a computer processes must be encoded digitally, as a series of zeroes and ones. Every computer has a set of instructions that define the basic functions it can perform. Sequences of these instructions constitute machine-language programs that can be stored in a computer to tailor it to an essentially unlimited number of specialized applications. Calculators are small computers specialized for mathematical computations. General-purpose computers range from pocket size personal digital assistants (note-pd computers), to medium-sized computers (personal computers and workstations), to large powerful computers that are shared by many users via a computer network. Special-purpose microcontrollers are embedded, often visibly,, in devices like toys, consumer electronic equipment, and automobiles.

The main data processing elements of a computer reside in a small number of electronic integrated circuits (ICs) that form a microprocessor or central processing unit (CPUs). Electronic technology allows a basic instruction such as “add two numbers” to be executed many millions of times per second. Other electronic devices are used for program and data storage (memory circuits) and for communication with external devices and human users (input-output circuits) devices appear also to computers. They are used to construct input-output devices such as keyboards, monitors (video screens), secondary memories, printers, sensors, and mechanical actuators.

A. After reading the text write the devices mentioned in it under each column.

 Analogue devices Digital devices

B. Match the words or phrases in the two columns.

 calculator notepad computer desktop computer microcontroller powerful computer network server digital assistant mathematical computations PCs Automobiles, toys etc.

C. Indicate which of the sentences are true (T) or false (F).

1. A conventional clock (with hands) shows a more detailed time than a digital.

2. An amplifier reads digital data.

3. Demodulating happens when a signal is turned from digital to analogue.

4. A modem helps to turn from digital to analogue.

5. An analogue computer can be used by a car designer to test a new model.

D. Match the following verbs with their definitions.

 modulate encode tailor embed fix firmly and deeply in a surrounding solid mass. Adapt so as to make suitable for something specific. Adjust or regulate the degree of. Convert symbols into a digital form as a series of impulses

E. Match the following nouns with their definitions

 circuit vibration rotation suspension amplifier regular cycle of events in a set order or sequence electronic devise to increase the strength of a current or voltage signal complete path through which an electric current flows movement back and forth rapidly a system of springs, shock absorbers, etc., that supports the body of a wheeled or tracked vehicle

F. Find the words from text on analogue computers that match the following definitions.

1. rigidity. Inflexibility (2nd paragraph)

2. any method of dispersing energy in a vibrating system (2nd paragraph)

3. having a countable number of elements (3rd paragraph)

4. recognize or observe (3rd paragraph)

5. a series of systematic changes (3rd paragraph

G. Fill in the missing words from the list.
analogue, binary, digits, digital, storage, proceeding
AQ computer stores data in terms of ____________ and proceeds in discrete steps from one state to the next. The states of a digital computer typically involve _____________ digits, which may take the form of the presence or absence of magnetic markers in a _____________ medium (memory), on-off switches or relays. In ________________ computers, even letters, words or whole texts are represented digitally. Unlike ______________ computers, digital computers can only approximate a continuum by assigning a large number of digits to a state description and by ______________ in arbitrarily small steps.
H. Fill in the missing words from the list.
rotation, signal, accuracy, continuous, quantities, variables
An analogue device is an apparatus that measures ______________ information. The measured analogue _____________ has an infinite number of possible values. The only limitation in resolution is the ________________ of the measuring device. Such apparatus operates with _______________ which are constituted by continuously measured quantities. These ______________ can be voltage, resistance, _________________ and pressure.
I. Find derivatives of the following verbs and classify them as verbs, adjectives and nouns: manipulate, encode, tailor, transmit, modulate, compute

VOCABULARY

Text

device = συσκευή

represent = αντιπροσωπεύω

value = τιμή

variable = μεταβλητή

numerical = αριθμητικός

rotation = περιστροφή

displacement =μετατόπιση

charge = φορτίο

operate = λειτουργώ

stiffness = ακαμψία

damping = ελάτωση, σβήσιμο

indicate = δηλώνω, δείχνω

in contrast = σε αντίθεση

finite = ορισμένος, που έχει τέλος

perceive - αντιλαμβάνομαι

smooth = ομαλός

array = σειρά

approximation = προσέγγιση

relatively = σχετικά

storage = αποθήκευση

transmission = μετάδοση

amplify - ενισχύω

frequency = συχνότητα

process = επεξεργάζομαι

discontinuous = ασυνεχής

application = εφαρμογή

binary = δυαδικός

encode = κωδικοποιώ

sequence = ακολουθία

specialize = ειδικεύομαι

embed = ενσωματώνω

instruction = εντολή

 Exercise C Exercise D Conventional = συμβατικός Detailed = λεπτομερής amplifier = ενισχυτής firmly = σταθερά surrounding = περιβάλλων solid = ενιαίος mass = μάζα adapt = προσαρμόζω adjust = ρυθμίζω convert = μετατρέπω

 Exercise E Exercise F sequence = ακολουθία current - ρεύμα signal = σήμα path = διαδρομή flow = ρέω rapidly = πολύ γρήγορα back and forth = πίσω-μπρός spring = ελατήριο shock absorber = αμορτισέρ rigidity = ακαμψία inflexibility = ανελαστικότητα disperse = διαχέω vibrating = δονούμενος countable = μετρήσιμος

 Exercise G Exercise H discrete = διακριτός, συγκεκριμένος store = αποθηκεύω involve = περιλαμβάνω switch = διακόπτης relays = ρελέ unlike = αντίθετα από apparatus = συσκευή measure = μετρώ infinite = απεριόριστος resolution = ανάλυση limitation = περιορισμός constitute - αποτελώ resistance = αντίσταση pressure = πίεση