Giáo trình anh văn chuyên ngành dành cho bậc cao đẳng ngành điện công nghiệp, công nghệ kỹ thuật điện điện tử, công nghệ kỹ thuật điện tử, truyền thông, điện tử công nghiệp

- Ý nghĩa và vai trò của môn học/mô đun: Nội dung học phần Anh văn chuyên ngành được thiết kế dành cho sinh viên có trình độ tiếng Anh với các nội dung: Electronics in the home, Safety a

MỤC LỤC

A DANH MỤC CHỮ VIẾT TẮT

- AC: Alternating current

- ADC: Analog to digital converter

- AF: Audio frequency

- AM: Amplitude modulated

- ATV: Advanced television

- CAD: Computer aided design

- CB: Circuit breaker

- CD: Compact disc

- CMOS: Comlpementary metal oxide semiconductor

- CPU: Central processing unit

- CRO: Cathode ray oscilloscope

- CRT: Cathode ray tube

- DAC: Digital to analog converter

- DC: Direct current

- EMF: Electromotive force

- FET: Field effect transistor

- FM: Frequency modulated

- HDTV: High definition television

- Hi-fi: High fidelity

- IC: Integrated circuit

- ISDN: Integrated services digital network

- IT: Information technology

- LAN: Local area network

- LCD: Liquid crystal display

- LDR: Light dependent resistor

- LED: Light emitting diode

- MSI: Medium scale integration

- OPAMP: Operatinal amplifier

- PCB: Printed circuit board

- PCM: Pulse code modulation

- RAM: Random access memory

- ROM: Read only memory

- RF: Radio frequency

- SSI: Small scale integration

- TV: Television

- TTL: Transistor-transistor logic

- UHF: Ultra high frequency

- VHF: Very high frequency

- VLSI: Very large scale integration

B DANH MỤC BẢNG BIỂU SỐ LIỆU

Table 1 Material properties 28

Table 2 Tolerances of resistor 38

Table 3 colour bandings of the capacitors 39

Table 4 the differences between two kinds of cells 45

Table 5 Student A's table: 47

Table 6 Student B's table: 47

Table 7 Small-signal low-frequency silicon transistors 54

C DANH MỤC CÁC HÌNH Figure 1.1 The block diagram of a simple radio 9

Figure 1.2 The circuit diagram forthe simple radio 10

Figure 1.3 The block diagram of an amplitude-modulated (AM) radio transmitter 13

Figure 3 1 The motor of washing machine 30

Figure 3 2 A simple electric motor 30

Figure 5 1 The circuit diagram of a battery charger 49

Figure 5 2 The block diagram of a battery charger 49

Figure 5 3 The first stage 50

Figure 5 4 The second stage 50

Figure 5 5 The third stage 51

Figure 5 6 The final stage 51

Figure 7 1 Company structure 74

D PHẦN NỘI DUNG UNIT 1: ELECTRONICS IN THE HOME 7

I TURNING 8

II READING FOR A PURPOSE 9

III UNDERSTANDING ELECTRONIC DIAGRAMS 9

IV LANGUAGE STUDY DESCRIBING BLOCK DIAGRAMS AND CIRCUITS 10

V SPEAKING PRACTICE 11

VI WRITING: DESCRIBING DIAGRAMS 13

UNIT 2: SAFETY AT WORK 15

I TUNING IN 16

II READING: UNDERSTANDING THE WRITER’S PURPOSE 19

III LANGUAGE STUDY: MAKING SAFETY RULES 21

IV WRITING: WAYS OF LINKING IDEAS 22

UNIT 3: THE ELECTRIC MOTOR 25

I TUNING IN 26

II READING: SCANNING AND SKIMMING 26

III LANGUAGE STUDY: DESCRIBING FUNCTION 31

IV WRITING: DESCRIBING COMPONENT 32

V WORD STUDY 34

UNIT 4: COMPONENT VALUES 36

I TECHNICAL READING: RESISTOR VALUES 37

II TECHNICAL READING: CAPACITOR VALUES 39

III TECHNICAL READING: DIODES CODE 39

IV WRITING: LINKING FACT AND IDEAS 41

UNIT 5: BATTERIES 44

I TUNING IN 44

II LANGUAGE STUDY: DESCRIBING COMPONENT 45

III SPEAKING PRACTICE 47

IV WORD STUDY: VERBS AND RELATED NOUNS 48

V TECHNICAL READING: BATTERY CHARGER 49

VI WRITING: DESCRIBING DIAGRAMS 52

UNIT 6: TRANSISTORS AND ELECTRICAL DEVICES CHARACTERISTICS 53

I TUNING IN 54

II READING: LOCATING AND APPLYING INFORMATION 55

III WRITING 1: DESCRIBING TRANSISTOR CHARACTERISTICS 56

IV READING: DATASHEET AND INSTRUCTION SHEET 56

UNIT 7: APPLYING FOR A JOB 65

I TUNING IN 66

II READING: UNDERSTANDING JOB ADVERTISEMENTS 66

III WRITING: WRITING A CV AND LETTER OF APPLICATION 69

IV TECHNICAL READING: COMPANY STRUCTURE 73

E TÀI LIỆU THAM KHẢO

[1] Eric H Glendinning – Jonh McEwan, Oxford English for Electronics, Oxford

University Press, 2010

[2] Eric H Glendinning – Norman Glendinning, Oxford English for Electrical and Mechanical, Oxford University Press, 2010

[3] Virginia Evans-Jenny Dooley-Tres O’Dell, Electrician, Express Publishing, 2012

F PHỤ LỤC

- Ý nghĩa và vai trò của môn học/mô đun: Nội dung học phần Anh văn chuyên

ngành được thiết kế dành cho sinh viên có trình độ tiếng Anh với các nội dung: Electronics in the home, Safety at work, The electric motor, Component values, Batteries, Transistor and electrical devices characteristic, Applying for a job Ứng dụng của tiếng Anh trong kỹ thuật điện-điện tử, điện tử truyền thông, điện công nghiệp, điện tử công nghiệp;

o Sử dụng, vận hành được các thiết bị có bảng hướng dẫn bằng tiếng Anh;

o Điền được các thông tin trong mẫu CV xin việc bằng tiếng Anh

UNIT 1: ELECTRONICS IN THE HOME

Giới thiệu: Nội dung bài học này cung cấp cho người học kiến thức về tên gọi bằng

tiếng anh của các thiết bị điện, điện tử trong gia đình; tên tiếng anh của các linh kiện điện tử và ý nghĩa tiếng anh của những từ viết tắt thường dùng trong lĩnh vực điện, điện tử Đồng thời giúp người học diễn đạt được sơ đồ nguyên lý, sơ đồ khối của một thiết bị điện-điện tử bằng tiếng anh

Mục tiêu:

- Về kiến thức:

+ Trình bày được tên của các thiết bị điện-điện tử thường dùng trong dân dụng

và công nghiệp bằng tiếng anh;

+ Khái quát được ý nghĩa của những cụm từ viết tắt bằng tiếng anh trong lĩnh vực điện, điện tử

- Về kỹ năng:

+ Miêu tả được sơ đồ nguyên lý và sơ đồ khối bằng tiếng anh

+ Đọc được tên tiếng anh của các linh kiện điện, điện tử cơ bản

I TURNING

Task 1: Make a list of things in your house which use electronics Compare your list

with that of another group

Task 2: Find out the meaning of these abbreviations

a) AC b) DC c) CD d) hifi e) PC f) IC

Task 3: Read quickly through the text on the next page Underline any items mentioned

in the list you made in Task 1

Electronics in the home

Electronics began at the start of the twentieth century with the invention of the vacuum tube The first devices for everyday use were radios, followed by televisions, record players, and tape recorders These devices were large and used a lot of power

The invention of the transistor in 1947 meant that much smaller, low- powered devices could be developed A wide variety of electronic devices such as hi-fi units and portable radios became common in the home

It was not until 1958 that microelectronics began with the development of ICs (integrated circuits) on silicon chips This led to a great increase in the use of electronics in everyday items The introduction of the microprocessor allowed electronics to be used for the control of many common processes

Microprocessors are now used to control many household items such as automatic washing-machines, dishwashers, central heating systems, sewing machines, and food processors Electronic timers are found in digital alarm clocks, water heaters, electric cookers, and microwave ovens Telephones use electronics to provide automatic dialling and answerphone facilities New entertainment devices have been developed, such as video recorders and CD (compact disc) players

In the future, electronics are likely to become even more common in the home

as multimedia entertainment systems and computer controlled robots are developed

Task 4: Fill in the gaps in this table with the help of the text

Early 20th century

transistor

1958 automatic washing

machines

Task 5: Make a list of ways in which you think electronics may be used in the home in the future

II READING FOR A PURPOSE

In electronics, you have to read not only texts, but also diagrams You have to

be able to combine information from both diagram and text This text introduces two kinds of diagrams often used in electronics

Task 6: Read the text below to find the answers to these questions:

1 What do we call the two types of diagrams shown in the text?

2 What do we call the approach to electronics which focuses on the function of units?

III UNDERSTANDING ELECTRONIC DIAGRAMS

Although electronic devices may look complicated, they are made up of common basic units ('building blocks') connected together The function of each of these units and the path of the signals between them can be shown in a block diagram For example, the block diagram of a simple radio is shown in Fig 1.1

Figure 1.1 The block diagram of a simple radio

To understand how the radio works, it is more important to understand the function of each unit than to know what components are used This is known as a systems approach to electronics For example, in Fig 1 the tuner selects the required signal, the detector 10 then separates off the audio part of the signal, and the AF amplifier (amp) amplifies it

The connections and values of the components inside these basic units can

be shown in a circuit diagram using standard electronic symbols Fig 1.2 shows the circuit diagram forthe simple radio

Figure 1.2 The circuit diagram for the simple radio

Task 7: How many of the circuit symbols in Fig 2 can you identify? Use the

Appendix on page 62 to help you

IV LANGUAGE STUDY DESCRIBING BLOCK DIAGRAMS AND CIRCUITS

Look again at Fig 1 above We can describe it like this:

The radio consists of a tuner, a detector, and an AF amplifier

Or we can describe it like this:

The radio is composed of a tuner, a detector, and an AF amplifier

Using comprise, we can start our description with the block:

A tuner, a detector, and an AF amplifier comprise the radio

We can describe the links between each building block using these expression:

The tunner is connected to the detector

The tunner is linked to the detector

Look again at Fig 2 We can describe the values of the components like this:

R1: a two-hundred-and-twenty-kilohm resistor

C2: a hundred-picofarad (puff) capacitor

Task 8: Describe the value of these components:

1 R2

2 C1

3 R3

4 C3

5 P1

6 L1

This table provides the terms you need

The volume control consists of a ten-microfarad electrolytic capacitor connected

in series with a five-kilohm potentiometer (pot) The positive terminal of the capacitor

is connected to the output of the AF amplifier and the wiper of the pot is connected to the power amp The 5 third terminal of the pot is connected to the zero voltage supply rail, which is earthed

Task 9: Fill in the gaps in this description of the tuned circuit shown in Fig 2 Each gap

represents one word

The circuit 1 of a four hundred and seventy 2 inductor which is connected in parallel with a 3 capacitor The 4 can be varied between five and sixty-five 5 The aerial is 6 to the top end of the tuner It is also connected to the positive terminal of the 7 in the detector The bottom end of the tuner is connected to earth via the zero voltage 8 rail

V SPEAKING PRACTICE

Task 10: Work in pairs, A and B Complete your circuit diagram with help from your

partner

Ask questions like these:

What kind of component is P1?

What’s the value of C1?

What is connected between the collector of Q2 and the positive side of the battery?

If you don’t understand your partner, say:

I’m sorry, I don’t understand Could you say that again, please?

Could you speak more slowly?

If your partner doesn’t understand you at first, try phrasing your answer in a different way For example:

It’s a variable resistor It’s a resistor which you can vary or change by turning the control It’s called a variable resistor

Student A's circuit diagram:

Student B's circuit diagram:

VI WRITING: DESCRIBING DIAGRAMS

With the help of the diagram, fill in the gaps in the description below Each gap represents one word The description should answer these questions:

1 What is the diagram of?

2 What does it consist of in terms of blocks?

3 How are the blocks connected?

4 What is the function of each block?

Figure 1.3 The block diagram of an amplitude-modulated (AM) radio transmitter

This figure shows the block diagram of an amplitude-modulated (AM) radio

transmitter It 1 of a radio frequency (RF) oscillator, a 2 , an audio

frequency (AF) amplifier, and an RF power amplifier.The RF 3 generates an

RF 4 wave which is fed into the modulator

The microphone converts sounds into audio frequency signals which are

amplified by the AF 5 The modulator then uses the amplified AF 6 to

modulate the RF carrier wave

The power of the modulated carrier wave is increased by the RF amplifier 7 The strong modulated output signals are fed to the 8 which enables them to

be transmitted over long distances

UNIT 2: SAFETY AT WORK

Giới thiệu: Bài này trình bày về các cảnh báo nguy hiểm trong lĩnh vực điện-điện tử

bằng tiếng anh Giúp sinh viên hiểu được các hướng dẫn an toàn lao động bằng tiếng anh; qua đó sinh viên có thể nắm được các ý chính và hiểu được một bảng báo cáo tai

nạn lao động bằng tiếng anh

Mục tiêu:

- Về kiến thức:

+ Khái quát được ý nghĩa của các biển báo nguy hiểm trong ngành điện, điện tử bằng tiếng anh

+ Hiểu được ý nghĩa của những biển cảnh báo về an toàn bằng tiếng anh

+ Khái quát được tên tiếng anh của các thiết bị bảo hộ an toàn lao động

- Về kỹ năng:

+ Đọc và hiểu được những chỉ dẫn an toàn bằng tiếng anh

+ Viết được một bản báo cáo tai nạn bằng tiếng anh

I TUNING IN

Task 1: What do these warning labels mean? Match each label to the correct warning

3 High voltage 6 Arc flash 9 Battery charging area

Task 4: Study the safety instructions from a workshop below, and then answer these questions

a Who are the instructions for?

b Who wrote them?

c What was the writer's purpose?

1 Wear protective clothing at all times

2 Always wear eye protection when operating lathes, cutters, and grinders and ensure the guard is in place

3 Keep your workplace tidy

4 The areas between benches and around machines must be kept clear

5 Tools should be put away when not in use and any breakages and losses reported,

6 Machines should be cleaned after use

II READING: UNDERSTANDING THE WRITER’S PURPOSE

Knowing what the writer's purpose is, who the writer is, and who the intended readers are can help us to understand a text The safety instructions in Task 3 are clearly intended to encourage employees to be safety conscious and reduce the risk of accidents The writer is perhaps a supervisor or the company safety officer, and the intended readers are machine operatives Knowing these things can help us to work out the meaning of any part of the text we may not understand

Task 5: Study the company document on safety on the text, and then answer these

questions

Accident investigation

Whenever an accident occurs that results in an injury (medical case), damage of equipment and material, or both, prompt accident investigation by the immediate manager is required A written preliminary investigation will be completed by the end

of the particular shift or business day on which the accident occurred

In no event should there be a delay of more than 24 hours Failure to comply with this requirement may subject the immediate manager to disciplinary action up to and including discharge

Without adequate accident investigation data the Company may be subjected to costs, claims, and legal action for which it has no defence

As a minimum, the preliminary accident investigation report will include the following:

1 Name, occupation, and sex of injured worker

2 Place and date /time of accident

3 Description of how the accident happened

4 Immediate causes of the accident - unsafe acts and unsafe conditions

5 Contributing causes - manager safety performance, level of w'orker training, inadequate job procedure, poor protective maintenance, etc

6 Witness(es) - name and department

7 Corrective action taken - when

The employee who was injured and any employee(s) who witnessed the incident should be separately interviewed as soon as possible A copy of the report must be submitted to the Manager - Human Resources for review Another copy of the report is

to be retained for a period of not less than the injured employee's length of employment plus five (5) years

1 Who is this document for?

a) machine operatives

b) managers

c)all employees

d) injured employees

2 Who wrote this document?

a) trade union representative

b) to ensure speedy help for injured employees

c) to protect the company

d) to warn about dangers

Task 6: Study this brief report of an accident In which points does it not meet company

policy on reporting accidents?

To: Name Departments Location Date

Subject Preliminary Report, Accident, 12 May

While turning a brass component on Tuesday, last week, Kenneth Oliver, machinist, received an injury to his eye He was taken to the Eye Hospital where I understand he

was operated on I believe the accident was due to carelessness

III LANGUAGE STUDY: MAKING SAFETY RULES

What are the differences in meaning between these statements?

1 Wear protective clothing

2 Always wear protective clothing

3 Protective clothing must be worn

We can make safety rules in these ways:

1 Using an imperative

Wear protective clothing

Do not wear loose-fitting clothing

2 Always/never are used to emphasize that the rule holds in all cases

Always wear protective clothing

Never wear loose-fitting clothing

3 We can use a modal verb for emphasis

Protective clothing must be worn

Protective clothing should be worn

Task 7: Study this list of unsafe environmental conditions (hazards) Write safety rules

to limit these hazards using the methods given above For example:

inadequate lighting

Lighting must be adequate

or Lighting should be adequate

1 uneven floors

2 unguarded machinery

3 untidy workbenches

4 untidy workplaces

5 badly maintained machinery

6 carelessly stored dangerous materials

7 inadequate ventilation

8 damaged tools and equipment

9 machinery in poor condition

10 equipment used improperly

11 equipment operated by untrained personnel

12 apprentices working without supervision

IV WRITING: WAYS OF LINKING IDEAS

When we write, we may have to describe, explain, argue, persuade, complain, etc In all these forms of writing, we use ideas To make our writing effective, we have to make sure our readers can follow our ideas One way of helping our readers is to make the links between the ideas in our writing

What are the links between these pairs of ideas? What words can we use to mark the links?

1 Mechanisms are important to us

2 They allow us to travel

3 Mechanisms deliver the power to do work

4 They play a vital role in industry

5 Friction is sometimes a help

6 It is often a hindrance

Sentence 2 is a reason for sentence 1 We can link 1 and 2 like this:

Mechanisms are important to us because/since/as they allow us to travel

Sentence 4 is the result of sentence 3 We can link 3 and 4 like this:

Mechanisms deliver the power to do work so they play a vital role in industry Mechanisms deliver the power to do work; therefore they play a vital role in

industry

Sentence 6 contrasts with sentence 5 We can link 5 and 6 like this:

Friction is sometimes a help but it is often a hindrance

Task 8: Show the links between these sets of ideas using appropriate linking words

1 Copper is highly conductive

It is used for electric wiring

2 Weight is measured in newtons

Mass is measured in kilograms

3 Nylon is used for bearings

It is self-lubricating

4 ABS has high impact strength

It is used for safety helmets,

5 Friction is essential in brakes

Friction is a nuisance in an engine

We learnt how to make our writing effective, we have to make sure our readers can follow our ideas We learnt how to mark reasons, results, and contrasts

in our writing

What are the links between these ideas? What words can we use to mark the links?

1 The accident happened

2 The operator's carelessness

3 The supervisor was not present

Sentence 2 is a reason for sentence 1 Sentence 3 is an additional reason We can mark

the links between them like this:

The accident happened because of the operator's carelessness In

addition/moreover, the supervisor was not present

We use because of to introduce a reason which is a noun or noun phrase We use in

addition and moreover to introduce an additional reason

What are the links between these ideas? What words can we use to mark the links?

4 Suitable protection should be worn

5 Safety helmets should be used where there is a danger of falling objects

Sentence 5 is an example to illustrate sentence 4 We can mark this in this way:

Suitable protection should be worn For example/For instance, safety helmets

should be used where there is a danger of falling objects

Task 9: Show the links between these sets of ideas using appropriate linking words

1 Many accidents happen

Workers' carelessness

2 Education can reduce accidents

It is important that all workers receive training in basic safety

3 Eye injuries can be serious

Goggles must be worn for grinding and cutting

4 Safety gloves provide protection for the hands

They prevent burns

They reduce the danger of cuts

5 Safety shoes protect the feet against falling objects

They prevent the feet getting caught in machinery

6 Respirators should be worn in dusty conditions

Dust can damage the lungs

7 Safety gear exists for every danger

Each year people are injured

They refuse or forget to wear the right gear

UNIT 3: THE ELECTRIC MOTOR

Giới thiệu: Bài này tập trung hướng dẫn sinh viên cách đọc các thông số kỹ thuật của

động cơ bằng tiếng anh thông qua kỹ thuật đọc lướt và đọc dò (Scanning and Skimming) Đồng thời qua bài học này, sinh viên biết được tên gọi bằng tiếng anh của các loại động

cơ và các thành phần bên trong động cơ để từ đó có thể diễn đạt được cấu tạo của động

cơ bằng tiếng anh

Mục tiêu:

- Về kiến thức:

+ Khái quát được tên gọi bằng tiếng anh của các loại động cơ thông dụng

+ Trình bày được cấu tạo của động cơ bằng tiếng anh

- Về kỹ năng:

+ Đọc và hiểu được các thông số kỹ thuật của động cơ trên nhãn động cơ

+ Miêu tả được chức năng của các thành phần bên trong động cơ bằng tiếng anh

I TUNING IN

Task 1:Working in your group, list as many items as you can in the home which use

electric motors Which room has the most items?

II READING: SCANNING AND SKIMMING

In engineering it is important to practise reading tables, charts, diagrams, and graphs because so much information is presented in these ways We will start in this unit with a table

Scanning is the best strategy for finding information in a table With scanning, you know before you read what sort of information you are searching for To scan a table, you move your eyes up and down the columns until you find the word or words you want To scan quickly, you must learn to ignore any information which will not help you with your task

Task 2: Scan the nameplate of the motor below to find:

6 conductive and malleable

7 durable and hard

8 stiff and brittle

9 ductile and corrosion-resistant

10 heat-resistant and chemical-resistant

Table 1 Material properties

Metals

Aluminium

Light, soft, ductile, highly conductive, corrosion-resistant

Aircraft, engine components, foil, cooking utensils

Copper

Very malleable, tough and ductile, highly conductive, corrosion-resistant

Electric wiring, PCBs tubing

hardened and tempered

Cutting tools such as drills, files, saws

Acrylic

Stiff, hard, very durable, clear, can be polished easily Can be formed easily

Aircraft canopies, baths, double glazing

wear-resistant, self- lubricating

Bearings, gears, casings for power tools

Thermosetting plastics

Epoxy resin

High strength when reinforced, good chemical and wear resistance

Adhesives, encapsulation

of electronic components

Polyester resin

Stiff, hard, brittle Good chemical and heat resistance

Moulding, boat and car bodies

Urea formaldehyde

Stiff, hard, strong, brittle, heat- resistant, and a good electrical insulator

Electrical fittings, adhesives

Task 4: Scan the table above to find:

1 A metal used to make aircraft

2 Plastics used for adhesives

3 Steel which can be hardened

4 An alloy suitable for castings

5 A plastic with very low friction

6 A material suitable for safety helmets

7 A metal suitable for a salt-water environment

8 A metal for general construction use but which should be protected from corrosion

9 A plastic for car bodies

10 The metal used for the conductors in printed circuit boards

You studied scanning - locating specific information quickly Another useful strategy is reading a text quickly to get a general idea of the kind of information it contains You can then decide which parts of the text are worth reading in more detail later, depending on your reading purpose This strategy is called skimming

Task 5: Skim this text and identify the paragraphs which contain information on each

of these topics The first one has been done for you

In an electric motor an electric current and magnetic field produce a turning movement This can drive all sorts of machines, from wrist-watches to trains The motor shown in Fig 3.1 is for a washing machine It is a universal motor, which can run on

direct current or alternating current (Paragrap 1)

An electric current running through a wire produces a magnetic field around the wire If an electric current flows around a loop of wire with a bar of iron through it, the iron becomes magnetized It is called an electromagnet; one end becomes a north pole and the io other a south pole, depending on which way the current is flowing around the

loop (Paragrap 2)

Figure 3 1 The motor of washing machine

If you put two magnets close together, like poles - for example, two north poles

repel each other, and unlike poles attract each other (Paragrap 3)

In a simple electric motor, like the one shown in Fig 3.2, a piece of iron with loops of wire round it, called an armature, is placed between the north and south poles

of a stationary magnet, known as the field magnet When electricity flows around the

armature wire, the iron becomes an electromagnet (Paragrap 4)

Figure 3 2 A simple electric motor

The attraction and repulsion between the poles of this armature magnet and the poles of the field magnet make the armature turn As a result, its north pole is close to the south pole of the field magnet Then the current is reversed so the north pole of the armature magnet becomes the south pole Once again, the 25 attraction and repulsion between it and the field magnet make it turn The armature continues turning as long

as the direction of the current, and therefore its magnetic poles, keeps being reversed

(Paragrap 5)

To reverse the direction of the current, the ends of the armature wire are

connected to different halves of a split ring called a 30 commutator Current flows to and from the commutator through small carbon blocks called brushes As the armature

turns, first one half of the commutator comes into contact with the brush delivering the current, and then the other, so the direction of the current keeps being reversed

(Paragrap 6)

Source: Adapted from 'Inside out: Electric Motor', Education Guardian

a What electric motors are used for Paragraph 1

Task 6: Match each of these diagrams with the correct description A, B, C or D One

of the descriptions does not match any of the diagrams (The diagrams are in the

correct sequence, but the descriptions are not.)

A The armature turns a quarter of a turn Then electric contact is broken because of the

gap in the commutator, but the armature keeps turning because there is nothing to stop

it

B When current flows, the armature becomes an electromagnet Its north pole is

attracted by the south pole and repelled by the north pole of the field magnet

C When a universal motor is run on direct current, the magnetic poles in the armature

change while those of the field magnet remain constant

D When the commutator comes back into contact with the brushes, current flows

through the armature in the opposite direction Its poles are reversed and the turn continues

III LANGUAGE STUDY: DESCRIBING FUNCTION

Try to answer this question: What does an electric motor do?

When we answer a question like this, we describe the function of something We can describe the function of an electric motor in this way:

An electric motor converts electrical energy to mechanical energy

We can emphasize the function like this:

The function of an electric motor is to convert electrical energy to mechanical energy

Task 7: Match each of these motor components to its function, and then describe its

function in a sentence

1 armature a transfers rotation from the motor

2 bearings b create an electromagnetic field

3 brushes c converts electromagnetic energy to rotation

4 commutator d reverses the current to the armature

5 drive shaft e support the drive shaft

6 field windings f.supply current to the armature

IV WRITING: DESCRIBING COMPONENT

Task 8: Dismantle this simple DC motor into its components by completing the

labelling of the chart below

Now study this description of the motor

A simple dc motor consists of a field magnet and an armature The armature is

placed between the poles of the magnet The armature is made up of a loop of wire and

a split ring known as a commutator The loop is connected to the commutator Current

is supplied to the motor through carbon blocks called brushes

To write a description, you need to use language to:

1 dismantle a piece of equipment into its main parts These expressions will help:

Task 9: Complete the text with the help of the diagram on the next page Use the

following words:

a are made up b is placed c is composed d consists

A transformer of two coils, a primary and a secondary The coils are wound on a former which is mounted on a core The coils of a number of loops of wire The core of thin pieces of soft iron, U- and T-shaped pieces are used The former on the leg of the T

Now label the diagram opposite using the completed text

V WORD STUDY

Study these expressions for describing how components are connected to each other

A is bolted to B = A is connected to B with bolts

A is welded to B = A is connected to B by welding

A is fixed to B = no specific method given

Task 10: Explain each of these methods of connection

8 brazed

9 nailed

UNIT 4: COMPONENT VALUES

Giới thiệu: Bài này giúp người học nắm rõ cách đọc giá trị các linh kiện điện tử bằng

tiếng anh, đồng thời cung cấp cho người học kiến thức về tên gọi của các loại linh kiện

điện tử thông dụng như điện trở, tụ điện, diode

Mục tiêu:

- Về kiến thức:

+ Khái quát được tên gọi bằng tiếng anh của các linh kiện điện tử cơ bản

+ Miêu tả được chức năng của linh kiện điện tử bằng mệnh đề quan hệ

- Về kỹ năng:

+ Đọc được giá trị linh kiện điện tử bằng tiếng anh

+ Phân loại được các loại diode, tụ điện, điện trở bằng tiếng anh

I TECHNICAL READING: RESISTOR VALUES

Task 1: Fill in the missing colours in this table with the help of the text

Tolerance: Red – 2%

Gold – 5%

Silver – 10%

No band – 20%

Reading the resistor code

Resistors are coded with coloured bands to ease the problem of marking such small components The numbers corresponding to the ten colours used and the values per position are shown above

For example, 180,000 ohms is coded with the first digit brown, then grey and finally yellow The fourth band indicates the tolerance that the value has with respect

to the stated value For example, silver indicates 10% tolerance, meaning that the 180,000 ohms could vary between 180,000 ± 18,000, i.e 162,000 to 198,000

These tolerances may seem to reflect poor manufacture but in most circuits they are, in fact, quite satisfactory Relaxing the tolerance enables the makerto sell them more cheaply

Task 2: Read this additional text Answer the question below, which refer to both text Preferred values

If the maker tried to produce and sell every value of resistance that exists, there would be chaos and the costs would be greatly increased The actual values made, therefore, are limited to a range called the preferred values These are listed in the table

The values may seem illogical at first sight, but this is not so They stem from the fact that the tolerance extremes of a value reach the extremes of adjacent values, thereby

covering the whole range without overlap Values normally available stop in the megohm decade

Table 2 Tolerances of resistor

1 Why are resistors coded with coloured bands rather than some other form of marking?

2 What would be the effect of making resistors with a much higher tolerance?

3 Between which values might a resistor marked green, blue, orange, and silver vary?

4 Why do manufacturers make resistors in the preferred values shown rather than in equally stepped values?

II TECHNICAL READING: CAPACITOR VALUES

Task 3: Use the following information to name the colour bandings of the capacitors

below (Note: 1 nF = l000pF) For example:

220pF, 2.5%

Band 1 red = 2 Band 3 brown = one zero

Band 2 red = 2 Band 4 orange = 2.5% tolerance

Table 3 colour bandings of the capacitors

C280 capacitor colour coding The first

three bands give the value (in pF) using

the same system as for the four band

Brown 1% yellow 400V

1 100pF, 20% 3 22nF, 5%, 250V

2 180pF, 10% 4 47nF, 20%

III TECHNICAL READING: DIODES CODE

Task 4: Identify these diodes with the help of the text below