ĐIỆN tử VIỄN THÔNG nhóm 4 khotailieu

Electronics in the home
D8-DTVT2
Group 4 :

Ngô Đắc Quân
Lê Văn Hoạch
Phùng Thế Quảng
Phạm Thị Minh Phượng
Nguyễn Thị Phương
Ngô Thị Phượng
Nguyễn Nhật Thư
Nguyễn Tuấn Anh


Task 1: Make a list of things in your home which use electronics.
Compare your list with that of another group.
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Television
Door bell
Lamp
Air Condition
Fan
Laptop
Dryer
Speakers
Radio
Smart Phone
Washing-machine

Task 2: Find out the meaning of these abbreviation. You can use

Appendix 1 on page 188 to help you
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IC : integrated circuit
CD: Compact dics
Hi- Fi: (high fidelity)

Task 3 : Read quickly through the text on the next page. Tick (x) any
item mentioned in the list you made in task.
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Electronics began at the start of twentieth century with the invention of
the vacuum tube. The first devices for every day use were radios,
followed by televisions, record players, and tape recorders. These
devices were large and use a lot of power. (X)
The invention of the transistor on 1947 meant that much smaller, lowpowered devices could be developed. A wide variety of electronic
devices such as hi-fi units and portable radios became common in the
home. (X)
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 of the microprocessor allowed
electronics to be used for the control of many common processes.


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Microprocessors are now used to control many household items such as
automatic washing-machines, dishwashers, central heating systems,
sewing machines and food processors. Electronics timers are found in
digital alarm clocks, water heaters, electric cookers and microwave
ovens. Telephones use electronics to provide automatic dialing and
answerphone facilities. New entertainment devices have been
developed, such as video recorders and CD (Compact disk) player. (X)
In the future, electronics are likely to become even more common in the
home as multimedia entertainment systems and computer controlled
robots are developed. (X)

Task 4 : Fill in the gaps in this table with the help of the text.
Date
Early 20 century
1947
1958
Future
th

Invention
Vacuum Tube
Transistor
Microelectronics
robot

Application in the home
Radio, TV, Record players

Hi-Fi units, portable radios
Automatic washing- machines
Computer controlled robots

Task 5 : Use the space below to make a list of ways in which you
think electronics may be used in the home in the future.
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Electonics car
Robot
Smart house controlled by smart phone
Multimedia entertainment systems
Door Automatic: open/ close
Lamp Automatic:turn on/ turn off in the home
Smart house controlled by voice
Smart watch
Electronics pen
Electronics glasses

Reading Understanding diagrams


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?
Block diagrams and Circuit diagrams.

2. What do we call the approach to electronics which focuses on the

function of units?
Systems approach to electronics.

Task 7 : How many of the circuit symbols in Fig.2 can you identify?
Use Appendix 2 on page 206 to help you.
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.
is composed of

Using comprise, we can start our description with the blocks:
A tuner, a detector, and an AF amplifier comprise the radio.

We can describe the links between each building block using these
expressions:
The tuner is connected to the detector.
is linked to

Look again at Fig.2. We can describe the values of the components like
this:
R1 : a two-hundred-and twenty-kilohm resistor (220K)
C2 : a hurdred-picofarad (puff) capacitor (100pF)

Task 8 :Describe the value of these components


1, R2 (1K) A one kilohm resistor
2, C1 (5-65 pF) A five-to-sixty-five-picofarad capacitor
3, R3 (47K) A Forty-seven kilohm resistor

4, C3 (10 uF) a ten-microfarad electrolytic capacitor
5, P1 (5K) a five-kilohm potentiometer (POT)
6, L1

This table provides the terms you need.
Prefix
Giga
Mega
Kilo
Deci
Milli
Micro
Nano
Pico

Symbol
G
M
K
D
M
µ
N
p

Mutiple
9

10
106

103
10-1
10-3
10-6
10-9
10-12

Example
GHz gigahertz
MΩ megohms
kV kilovolts
dB decibels
mW milliwatts
µH microhenries
nF nanofarads
pF picofarads

Looking now at the basic units of the circuit, we can describe the
volume control like this:
The volume control consists of a ten-microfarad electrolytic capacitor connected in
serial with a five-kilohm potentiometer (POT). The positive terminal of the
capacitor is connected to output of the AF amplifier and the wiper of the pot is
connected to power amp. The 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 consists of a four hundred and seventy microhenry inductor which is
connected in parallel with a variable capacitor. The capacitor can be varied
between five and sixty-five picofarad. The aerial is connected to the top end of

the tuner. It is also connected to the positive terminal of the diode in the detector.
The bottom end of the tuner is connected to earth via the zero voltage supply rail.

Speaking Practice


Task 10: Work in pairs
Task 11: Writing Describing diagrams
With the help of the diagrams, fill in the gaps in the description on page 12.
Each gap represents one word. The description should answer these questions
1
2
3
4

What is the diagram of?
What does it consist of in terms of blocks?
How are the blocks connected?
What is the funcion of each block?

Fig.3 shows the block diagrams of an amplitude-modulated (AM) radio transmitter.
It consists of a radio frequency (RF) oscillator, a modulator, an audio frequency
(AF) amplifier, and an RF power amplifier. The RF oscillator generates an Rf
carrier wave which is fed into the modulator.
The microphone converts sounds into audio frequency signals which are amplified
by the AF amplifier. The modulator then uses the amplified AFsignals to
modulator the RF carrier wave.
The power of the modulated carrier wave is increase by the RF poweramplifier.
The strong modulated output signals are fed to the aerial which enables them to be
transmitted over long

distances.