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Файл:Английский для студентов-энергетиков. Учебное пособие
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3) The transformer consists of two…: the primary and the secondary.
- to transfer
- to contain
- to eliminate
- to transform
- to control
- to compare
- to emit
- to produce
- to associate
- to regulate/to
check
- to convert
- to remove
- to hold/to
include
- to relocate
- to collect
- to stop
- to place
- to close
- to eliminate
- to separate
- to freeze
- to connect
- to include
- to open
- to displace
- to begin
-
4) The primary circuit is connected to the voltage source, the secondary-to the
load….
5) In case the coils of the coupling element are close together, the …is tight.
6) In case the …are separated the coupling is loose.
7) In the loose coupling the mutual …is small compared with the self-inductance.
Task 6. Find synonyms and antonyms for the following words from the text.
SYNONYMS
ANTONYMS
Task 7. Read the statements and decide whether you agree or disagree with
them. Say to what extent you agree or disagree and try to give your arguments:
-agree strongly
-agree
-not sure
-disagree
-disagree strongly
1) The primary circuit is connected to the voltage source, the secondary-to the load
circuit.
2) The coupling may be tight and loose.
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3) In case the coils of the coupling element are close together, the coupling is not
1) a Half-Wave Rectifier
2) a Full-wave Rectifier
3) a.c. source
4) centre tap
5) die
6) filament winding
7) a push-pull amplifier
8) grid voltage
a) смещение/отклонение сетки
b) последовательные каскады
c) сетевое напряжение
d) двухтактный усилитель
e) обмотка накала нити накала
f) матрица
g) центральный отвод
h) источник переменного тока
tight, it is loose.
3) In case the coils are separated the coupling is tight.
4) Therefore, the grid is called a control grid.
5) A tetrode contains the cathode, the plate, the control grid and the screen grid.
6) When a tube operates it may oscillate. The function of the screen grid is to
eliminate oscillations.
7) When a pentode operates the suppressor grid eliminates the secondary emission.
8) Common troubles in tubes are an open heater and high emission.
Task 8. Read the following descriptions and decide which one is about
d) A diode
e) A triode
f) A tetrode
g) A pentode
1. …… contains two electrodes and three grids: the control grid, the screen
grid and the suppressor grid.
2. ……… contains the cathode, the plate, the control grid and the screen grid.
When a tube operates it may oscillate. The function of the screen grid is to eliminate
oscillations. Therefore, it is called a screen grid.
3………. contains the cathode, the plate and the control grid. When the tube
operates the cathode emits electrons, the plate collects them and the grid controls the
flow of electrons. Therefore, the grid is called a control grid.
4………. contains the cathode and the plate. When a diode operates the
cathode emits electrons, the plate collects them.
Unit 4
Rectifier
Task 1. Match the following English words and phrases from text D with their
Russian equivalents:
62
9) stages in series
10) grid bias (displacement)
i) двухполупериодный выпрямитель
j) полуволновой выпрямитель
Task 2. Find the equivalents for the next word combinations and then make up
1) Однополупериодный
(полуволновой)
выпрямитель;
включенный диод;
3) источник переменного
тока;
4) пульсации устраняются;
5) нагрузочное
сопротивление;
6) по трубкам к катодам
7) через обмотку накала
a) through
a filament winding
their cathodes
c) a load resistance.
d) pulsations are eliminated
e) a.c. source (an alternating current
source);
f) a diode, connected in series;
g) half-wave rectifier
your own sentences:
Task 3. Read and translate text D:
Half-Wave Rectifier
«Alternating current is converted into direct current by means of a rectifier.
A half-wave rectifier consists of a diode in series with a resistance. In order to
put a rectifier into operation, a source of a.c. should be applied to it. When an a.c.
source is applied the diode begins to conduct. The rectifier passes currents during
positive half-cycles of the applied voltage. That is why it is called a half-wave
rectifier. When the device operates d.c. flows in the same direction. It is a pulsating
current. Since pulsations should be eliminated, a filter is applied. Pulsations are
eliminated by means of this filter.
load resistance. The secondary of the transformers has a centre tap to which the load
is connected. Current flows through the tubes from their plates to their cathodes.
In a full-wave rectifier two diodes are used. They are connected to a common
Full-wave Rectifier
63
When the upper end of the high-voltage winding is positive, current flows through
die upper tube.
During the opposite half cycle, the lower end of die high voltage winding
becomes positive. The plate of the lower tube becomes positive and the plate of the
upper tube negative, thus now the lower tube conducts current. Current flows
through the filament winding to its centre tap, then through the load to the centre tap
of the high-voltage winding and to the tube plate which is positive.
Push-pull Amplifier
An amplifier is used to produce the output voltage greater than the input
voltage. A push-pull amplifier includes two tubes. Their control grids are connected
to the opposite ends of the input transformer secondary winding. The centre of this
winding is connected to the tube cathodes. When maximum grid voltage is produced
in one tube, minimum grid voltage is produced in the other tube. Thus, the sum of the
plate currents remains constant.
The plate currents are fed into the opposite ends of the output transformer or a
choke coil. It has its centre connected through the plate current supply to the
cathodes. Thus direct current plate components are eliminated but alternating current
components add in the circuit.
Amplifier Stages in Series
Amplifiers in use nowadays contain several stages. Sometimes their number is
very great. Let us consider an amplifier including three stages. Its circuit uses three
triodes connected in series. The circuit has a resistance as the plate load. A common
plate voltage supply and a common grid bias are employed. The grid of each tube is
insulated from the direct current component of the plate voltage by means of a
capacitor. When the amplifier operates the voltage operation of the load of one tube is
applied to the grid of the next tube. The voltage variation is transferred to the grid of
the following tube through a capacitor.
A change of voltage on the first grid circuit results in an amplified plate
current in the third stage» [8].
Task 4. Answer the following questions:
1. Is alternating current converted into direct current by means of a rectifier?
2. What does half-wave rectifier consists of?
3. How is alternating current converted into direct current?
4. Does the rectifier pass currents during positive half-cycles of the applied
voltage?
5. What is applied to eliminate pulsations?
6. Are two diodes used in a full-wave rectifier?
7. When the upper end of the high-voltage winding is positive, current flows
through die upper tube, doesn’t it?
8. Does a push-pull amplifier include two or three tubes?
64
Task 5. Match the following words from the text with their definitions:
1) a generator
a)a crystalline piece of semiconductor material
with a p–n junction connected to two electrical terminals.
Semiconductor diodes were the first semiconductor
electronic devices.
2) an electric
power
transmission
which periodically reverses direction, to direct current (DC),
which flows in only one direction. The reverse operation is
performed by the inverter.
3) a high
voltage electricity
refers
c) amp is an electronic device that can increase
the power of a signal (a time-varying voltage or current). It
is a two-port electronic circuit that uses electric power from
a power supply to increase the amplitude of a signal applied
to its input terminals, producing a proportionally greater
amplitude signal at its output.
4) a diode is
d) a two-terminal electronic component that
conducts current primarily in one direction
(asymmetric conductance); it has low (ideally
zero) resistance in one direction, and high (ideally
infinite) resistance in the other. A diode vacuum
tube or thermionic diode is a vacuum tube with
two electrodes, a heated cathode and a plate.
5) an amplifier,
electronic
amplifier,
e) to electric potential, large enough to cause
injury or damage. In certain industries, high voltage refers to
voltage above a certain power.
6)a rectifier is an
electrical
f) is the bulk movement of electrical energy from
a generating site (place), such as a power plant, to
an electrical substation. The interconnected lines which
facilitate this movement are known as a transmission
network.
7) semicon
ductor
diode is
h) is a device that converts motive power (mechanical
energy) into electrical power for use in an
external circuit.
Task 6. Read the statements and decide whether you agree or disagree with
them. Say to what extent you agree or disagree and try to give your arguments:
-agree strongly
-agree
-not sure
-disagree
-disagree strongly
65
1) In order to put a rectifier into operation, a source of d.c. should be applied to it.
2) The rectifier passes currents during negative half-cycles of the applied voltage,
so it is called a half-wave rectifier.
3) When the rectifier operates d.c. flows in the other direction.
4) In a full-wave rectifier three diodes are used.
5) An amplifier is used to produce the output voltage greater than the input voltage.
6) Two tubes of the push-pull amplifier control grids, which are connected to the
opposite ends of the input transformer secondary winding.
7) When maximum grid voltage is produced in one tube, minimum grid voltage is
produced in the other tube.
Task 7. Read the following descriptions and decide which one is about
a) generator
b) a rectifier;
c) an amplifier
1. …… is used to increase the amplitude of a signal applied to its input
terminals, producing a proportionally greater amplitude signal at its output. resistance
2. ……… is used to convert alternating current (AC), which periodically
reverses direction, to direct current (DC), which flows in only one direction.
3. ……….. is used to convert motive power (mechanical energy) into
electrical power for use in an external circuit.
Task 8. Talk about the differences between Half-Wave and Full-wave
rectifiers.
Task 1. Match the following English words and phrases from text E with their
Russian equivalents:
Unit 5
AMPLIFIER STAGES IN SERIES
66
1) an electromagnetic relay
2) a spring
3) a secondary circuit
4) a cross-section
5) to bring (wires) to the
motor
6) a quartz-sand fuse
7) a short-circuit
8) a fuse protection
9) a fusible link
10) a faulty fusible element
a) неисправный плавкий элемент
b) плавкая вставка
c) предохранитель
d) короткое замыкание
e) кварцево-песчаный предохранитель
f) зд. подводить (провода) к
двигателю
g) поперечное сечение
h) вторичная цепь
i) пружина
j) электромагнитное реле
Task 2. Read and translate text E:
Electromagnetic Relay
«Electromagnetic devices called relays are widely used in various branches of
industry.
The main parts of a relay are an electromagnet, a spring and an armature. When
a current starts flowing in the electromagnet winding, the armature moves and the
spring closes the contacts. The primary circuit of a relay is its electromagnet circuit
and the secondary circuit is the one closed by the contacts.
armature and the contacts open.
circuit. The armature closes the contacts of the secondary circuit, and the motor starts
operating; it will stop when the relay opens.
brought to the motor. This would be very uneconomical. The current in a relay is
thousands of times smaller than that used to power the motor. Therefore, the
connecting wires can have small cross-sections.
When there is no current in the relay’s primary circuit, the spring pulls the
How a relay is used to control the work of an electric motor.
The relay is placed close to the motor which is connected to its secondary
Without a relay, conductors with a large cross-section would have to be
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In many systems the relay primary circuit operates automatically. Every
- to apply
- to control
- to defend
- to function
- to assist
- to be founded
- to be ranked
- to be rated
- to be based
- to serve
- to operate
- to protect
- to check
- to use
evening and morning street lights are switched on and off from the main control
panel by means of a great number of relays.
Fuses
Fuses are widely used nowadays as protection devices. They are utilized in
various circuits, electrical equipment and installations. Fuses serve to protect them
against overcurrents and short-circuits.
There are different types of fuses in use nowadays. One of them, quartz-sand
fuses, serve for voltages up to 500 volts; fuses of this kind are produced with current
ratings of 15 to 60 amp and of 100 to 350 amp. Fuses are commonly used in lowvoltage industrial installations rated up to 1,000 V.
Fuse protection is based on a very simple principle: in case of a short-circuit or
overcurrent, when the maximum value of current has been exceeded, the fusible link
of a fuse is heated to its melting point. This opens the circuit and disconnects the
circuit from the power source. In case of a fault, one should replace the faulty fusible
element by a new one. Fuses are used both in direct current (d.c.) and alternating
current (a.c.) circuits» [9].
Task 3. Answer the following questions:
1) What are the main parts of a relay?
2) What is the primary circuit of a relay?
3) When there is no current in the relay’s primary circuit, the spring pulls the
armature and the contacts open, doesn’t it?
4) Where is the relay placed?
5) Does the armature close the contacts of the primary, or secondary circuit?
6) Is the current in a relay higher or smaller than that used to power the motor?
7) Does the relay operate automatically in many systems?
Task 4. Find synonyms and antonyms for the following words from the text.
SYNONYMS
68
- to freeze
- to place
- to switch off
- to disconnect
- to begin
- to push
- to open
- to close
- to pull
- to stop
- to connect
- to switch on
- to replace
- to heat
text in the correct form: panel; relay; short-circuits; circuits; devices; crosssections; industry.
1. Electromagnetic devices called relays are widely used in various branches of….
2. Therefore, the connecting wires can have small …
3. Fuses are widely used nowadays as protection….
4. Fuses are utilized in various…, electrical equipment and installations.
5. Fuses serve to protect electrical equipment against overcurrents and …
6. In many systems the … primary circuit operates automatically.
7. Every evening and morning street lights are switched on and off from the main
control … by means of a great number of relays.
them. Say to what extent you agree or disagree and try to give your arguments:
1) When a current starts flowing in the electromagnet winding, the armature
moves and the spring closes the contacts.
2) Without a relay, conductors with a large cross-section would have to be
brought to the motor.
3) The current in a relay is thousands of times higher than that used to power the
motor.
4) There are different types of fuses in use nowadays.
5) Fuses are commonly used in High-voltage industrial installations.
6) In case of a fault, one should replace the faulty fusible element by a new one.
7) Fuses are used only in direct current (d.c.) but not alternating current (a.c.)
circuits.
ANTONYMS
Task 5. Complete the sentences using the following words or phrases from the
Task 6. Read the statements and decide whether you agree or disagree with
-agree strongly
-agree
-not sure
-disagree
-disagree strongly
69
Task 7. Find some information about the latest Fuses on the Internet and
1) a utilizing load
2) an incandescent lamp
3) a switch
4) a meter
5) an ammeter
6) a wattmeter
7) a fuse
8) a power loss
9) an outage
10) a conductor
11) a cord
a) шнур
b) провод
c) перебои
d) потеря мощности
e) предохранитель
f) ваттметр
g) амперметры
h) счетчик
i) переключатель
j) лампы накаливания
k) источник энергии
prepare a short report.
COMPONENTS OF ELECTRIC CIRCUITS
Task 1. Study the words and phrases from text F:
Unit 6
Task 2. Read and translate the text F:
Components of Electric Circuits
«The main components of any circuit are devices that produce and utilize
electric energy. They are: 1. power sources, 2. utilizing loads, 3. connecting
conductors.
The most common power sources are electric generators and primary cells.
Electric generators convert chemical energy into electric energy.
Loads include electric heaters, electric motors, incandescent lamps, etc. Motors
convert electric energy into mechanical, incandescent lamps and heaters convert
electric energy into light and heat. Utilizing devices or loads convert electric energy
into thermal, mechanical or chemical energy.
Electric power is delivered from power sources to loads by electric wires.
According to their material, wires can be aluminium, copper, steel, etc.
Besides, electric circuits use different types of switches, protection devices
(relays and fuses), and meters (ammeters, voltmeters, wattmeters, etc.).
Electric Lines and Their Efficiency
components of electrical installations. Conductors used for electric wiring are
commonly produced of copper and aluminium. Aluminium is widely used nowadays
due to its low cost. Copper is also widely used in electrical engineering but its cost is
much higher.
Wires are used to deliver electric power and to interconnect different
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