Методические указания для развития навыков устной речи дисциплине «Иностранный язык» для технических специальностей (стр. 2 )

6. The commutator is used for … .

7.Systems for control of electrical machine … have found wide application in modern industry.

8.The devices … by galvanic batteries appeared in the first half of the 19th century.

9. Many inventors … machines with an iron … that was … into a solenoid.

17. Выпишите ключевые слова, обозначающие этапы создания первого

двигателя.

Stages of Electrical Machine Building Development

a. Generator Construction

The first generators of electrical energy were galvanic elements producing direct current. Having worked with galvanic batteries, scientists of the first half of the 19th century constructed many devices powered by these batteries.

The first period of development of the electrical generator covers the years from 1831 to 1886.

The first technical model of a magnetoelectrlc generator was built soon after M. Faraday's discovery of the law of electromagnetic induction. In 1833 the English physicist W. Ritchie built a magnetoelectric machine having a commutator. The final design of the a. c. magnetoelectric machine of this period is the machine designed by F. Holmes in 1855 which was used for lighting buildings and for electro-chemical purposes. Ritchie was the first to suggest the use of electromagnets in electrical machines. It was during this period that the armature invented by W. Siemens and patented in 1856 and the ring armature constructed in 1860 became known. In 1876 P. Yablochkov developed the design of a single-phase synchronous generator, his generator being the prototype of modern synchronous machines.

The further development of synchronous generators is connected with the wide use of the three-phase a. c. system invented as a result of the work of the remarkable scientist and engineer M. Dolivo-Dobrovolsky.

b. Development of Electric Motors

M. Faraday's principle of conversion of electric energy into mechanical one formulated in 1882 was the beginning of electric motor design. Many scientists and inventors tried to repeat in the designs of their motors the scheme of the steam engine, the result being that the machines designed had an iron bar that was pulled into a solenoid.

In May 1834 the Russian scientist B. Jacobi constructed a multipole electric motor with a rotating armature having a device for reswitching current, this device being the prototype of the modern commutator.

By 1886 similar to the generator the electric d. c. motor had already attained the main features of its modem design. It was N. Tesla who constructed the first two-phase induction motors. Systems for control of electrical machine drives were created 50 years ago. These systems have found wide application in modem industry.

At present the field of electrical machine-building is in the stage of very rapid development.

18. Используя выписанные ключевые слова, расскажите об истории создания современного электромашиностроения.

Unit 3

Some Facts from the History

1. Прочитайте вслух новые слова, познакомьтесь с их русскими эквивалентами. Определите их значения в данных предложениях.

to present – 1. подавать; передавать на рассмотрение; 2. представлять, являть собой to obtain – 1. получать, добывать; 2. достигать, добиваться unit – 1. единица; 2. блок, комплект; 3. агрегат, секция, элемент advantage – преимущество ease – лёгкость to increase – увеличивать(ся), возрастать to decrease – уменьшаться, уменьшать commercial – торговый, коммерческий to transmit – передавать to step up – повышать, увеличивать to step down – понижать, уменьшать installation – установка, сооружение, устройство to supply – снабжать, подводить, питать further – 1.дальнейший; 2. более отдалённый by means of – посредством

The invention of the transformer presented a great contribution to the world science. It was difficult to obtain large units of power with the d. c. machine. The motor has many advantages over its prototype. Metals conduct electricity with ease. The transformers are used for increasing and decreasing the voltage. This type of motor has been used for commercial purposes since its construction. At present power may be transmitted over very long distances. The voltage was stepped up to 10.000 V; at a consumer’s end of the line it was stepped down to 113 V. The installation consisted of several separate units. The transformer supplied this voltage to an induction motor. The further development of long distance power transmission was connected with the invention of transformers. The voltage is increased or decreased by means of transformers.

Информация 8 Устойчивые словосочетания What is … used for? What is an electrostatic voltmeter used for? Для чего используется электростатический вольтметр? An electrostatic voltmeter is used for measuring voltage. Электростатический вольтметр используется для измерения напряжения.

2. Выпишите из текста названия приборов и устройств и скажите, для чего они

используются.

3. Образуйте существительные, обозначающие прибор или деятеля, с помощью суффиксов –er/–or и переведите их

to transform, to process, to operate, to manipulate, to instruct

4. Прочитайте текст и ответьте по-русски на следующие вопросы:

What difficulties did the d. c. machine present?

What was the importance of an a. c. transmission line?

What advantage have alternating current transmission lines over the direct current оnes?

What device did P. Yablochkov invent? When did he invent it?

Some Facts from the History of Power Transmission

Over Long Distances

The d. c. machine having been developed for special purposes presented many difficulties connected with obtaining of large units of power and high voltages. This problem was solved with the use of a. c. transmission lines which became almost universal.

However, owing to the modern highly developed a. c. to d. c. and d. c. to a. c. converter devices, direct-current high-voltage transmission lines have again appeared in many countries. Alternating current transmission systems have a great advantage over the direct current ones owing to the ease of increasing or decreasing the voltage by means of transformers both in too transmission and distribution systems.

It was the Russian scientist P. Yablochkov who invented the most important device in electrical engineering – the transformer used for the commercial transmission of power. This event took place in 1876.

The first long-distance three-phase a. c. transmission line was the one at the International Electric Engineering Exhibition at Frankfurt in 1891. It consisted of а 200 kw power plant at Lauffen from which electrical power was transmitted over a distance of 170 km to the exhibition. The three-phase generator of the plant had a power of 230 kvA and a voltage of 95V at 150 r. p.m., the voltage being stepped up by a transformer to 15.000 V at the exhibition a transformer stepped down the voltage to 113 V and supplied it to a 75 kw three-phase induction motor which was used to power a pump installation.

The invention of transformers as well as the increase of their voltage was a great contribution to the further development of long-distance electric power transmission.

5. Завершите предложения в соответствии с текстом

1. The d. c. machine presented many difficulties connected with … .

2. Alternating current transmission systems have a great advantage over … .

3. It was the Russian scientist Yablochkov who invented … .

4. The invention of transformers was a … .

6. Найдите в тексте и переведите: а. две терминологические группы; б. предложения со словом one.

7. Ответьте по-английски на следующие вопросы:

1. Did the d. c. machine present many difficulties?

2. Do alternating current transmission systems have a great advantage over the direct current ones?

3. Did the three-phase generator have a voltage of 95 V?

4. Was a 75 kw three-phase induction motor used to power a pump installation?

8. Используя выписанные ключевые слова, перескажите текст.

Unit 4

The Direct-Current Dynamo

1. Прочитайте вслух новые слова, познакомьтесь с их русскими эквивалентами. Определите их значения в данных предложениях.

to define – определять to supply – питать, снабжать, подавать unidirectional current – однонаправ- ленный ток to convert – превращать, преобразовывать (magnetic) lines of force – (магнитные) силовые линии prime mover – первичный двигатель (источник движущей силы) amount – количество to provide – обеспечивать, снабжать losses – потери sufficient – достаточный to occur – происходить, случаться to be on load – работать под нагрузкой to be at no-load – работать на холостом ходу (под нулевой нагрузкой) to act – действовать field magnet – возбуждающий магнит, обмотка возбуждения, индуктор to transfer – переносить, перемещать

Energy is defined as the ability to do work. The generator supplies electric energy. The dynamo gives a unidirectional voltage. A generator converts mechanical energy into electrical one. The stronger the magnet, the more magnetic lines of force pass through a space. The a. c. machine is driven by a prime mover. The current, voltage and resistance may change from a minute amount to a very large quantity. The prime mover provides some amount of energy. Sufficient energy losses occur in the dynamo. The machine is at no-load now. An electromotive force acts in the circuit. A field magnet is a principal part of a d. c. generator. The commutator transfers voltage to terminals.

2. Дайте значение производных слов

to produce – производить, вырабатывать to act – действовать to move – двигаться

production action motion

to connect – соединять connection

to insulate – изолировать insulation

to define – определять definition

to excite – возбуждать excitation

to vary – изменять (ся) variation

to operate – работать, действовать operation

3. Подберите к каждому термину из группы «а» соответствующее определение

из группы «б»

«a» 1. сurrent 2.dynamo 3.prime mover 4.e. m.f. 5.magnetic field 6.field magnet

7.armature 8.commutator

«б» 1. the part of a generator transferring voltage to terminals 2. the part of a dynamo producing the magnetic field 3.the region of influence of magnetic forces surrounding a magnet 4.a complete path carrying the current 5.the difference of potential causing electric currents 6.device converting mechanical energy into electrical one 7.the device driving a dynamo 8.the path of a dynamo carrying the system of moving conductors

Информация 9 Многозначность слов that – 1. тот (указательное местоимение) that amount – то количество 2. что, который (союз придаточных предложений) It is quite clear that … – Совершенно ясно, что … … the losses that take place … – … потери, которые имеют место 3.слово, заменяющее ранее упомянутое существительное во избежание его повторения The results of this experiment are much better than those of the previous one. Результаты этого эксперимента намного лучше, чем (результаты) предыдущего эксперимента.

4. Переведите предложения с многозначным словом that

1. An electric current passing through a conductor heats that conductor.

2. The outstanding Russian scientist Lenz discovered that when the current in a circuit increases, the flux also increases.

3. The action of a voltmeter is similar to that of an ammeter, both of them having armatures that move when en electric current is sent through their coils.

4. The deflection like that of the ammeter is proportional to the current flowing through the armature coil.

5. What is the amount of the voltage that causes the current?

6. That the accelerator of a falling body is constant was first shown by Galileo.

7. The machine that converts mechanical energy into electrical one is a generator.

8. That all matter consists of both negative and positive particles of electricity is understood from electron theory.

9. V. V. Petrov, the first Russian electrical engineer, discovered the effects of insulation as well as those of the cross-section of the wire.

Информация 10 Инфинитив Глаголы в форме инфинитива отвечают на вопрос «что делать?» to operate – действовать. В функции обстоятельства цели находится в начале или в конце предложения и переводится с помощью слов для, (для того) чтобы The prime mover is used to drive a dynamo.

5. Переведите предложения с инфинитивом в функции обстоятельства цели.

1. То convert mechanical energy into electrical one we use a generator.

2. To generate current a conductor passes through a magnetic field.

3. To produce a current by thermal action heat is applied to two unlike metals.

4. To measure very small currents one uses a galvanometer.

5. The commutator is used to transfer voltage to fixed terminals.

6. The field magnet is used to рroduce the magnetic field.

Информация 11 Объектный инфинитивный оборот (сложное дополнение) находится после сказуемого и переводится при помощи слов что, чтобы, как. We want you to tell us about solar energy. Мы хотим, чтобы вы рассказали нам о солнечной энергии.

Информация 12 Субъектный инфинитивный оборот (сложное подлежащее) Глагол в форме инфинитива стоит после сказуемого в форме Passive (is known–известно, is considered,is believed–полагают is expected–ожидают, is found–обнаружено и др.) This type of generator is said to have many… Говорят, что этот вид генератора имеет…

6. Переведите предложения с объектным и субъектным инфинитивным оборотом.

1. The chemical effect is known to occur when an alternating current flows

through а liquid.

2. We know the dynamo to produce a unidirectional voltage.

3. All modern d. c. dynamos are known to have more than two poles.

4. The prime mover is sure to supply energy sufficient for the losses in the dynamo.

5. Today we know atoms to be neither unchangeable nor indivisible.

6. The heating effect of the current is found to occur in the electrical circuit itself.

7. Thermocouples are likely to be used instead of semiconductors in the solar battery.

8. This old type generator is said to have many disadvantages.

9. We consider silver to be the best of conducting materials.

10. We want you to tell us about the solar energy.

11. The machine proved to be a very efficient generator.

12. We expect thermocouples to be used in the solar battery.

Информация 13 Глагол to be перед инфинитивом является эквивалентом модального глагола must - «должен», «обязан» The lecture is to begin at 8. Лекция должна начаться в восемь часов.

7. Переведите следующие предложения, обращая внимание на выделенные слова

1. The induced voltage is to be rectified.

2. Conductors of electricity are to cut the magnetic lines of force.

3. Professor N. was to deliver a lecture but he did not feel well.

Информация 14 Глагол to have перед инфинитивом является эквивалентом глагола must – «должен», «вынужден», «приходится» A scientist has to work hard. Учёный должен много работать. Учёному приходится много работать.

8. Переведите следующие предложения, обращая внимание на выделенные слова

1. They had to obtain better results.

2. We shall have to continue our experiments.

3. Those who have to translate this article may consult a dictionary.

9. Прочтите текст и скажите по-русски, какая деталь динамо-машины создаёт магнитное поле. Назовите деталь, состоящую из движущихся проводников.

The Direct – Current Dynamo

A generator of electric current can be defined as a machine that converts mechanical energy into electric one, the direct-current generator, or dynamo, being the one that supplies a unidirectional, unlike alternating current. The dynamo is known to be driven by some kind of prime mover that has to provide an amount of energy equal to that supplied by the dynamo, plus the various losses that occur in the dynamo. When the dynamo is said to be at no-load, that is, when it is not supplying any energy to the circuit to which it is connected, the prime mover has to supply energy sufficient for the losses that take place in the dynamo at no-load.

An electric current flowing through a circuit, there is an electromotive force (e. m.f.) acting in the circuit, and it is by electromagnetic induction that this e. m.f. is produced in the dynamo. Conductors of electricity are to move in such a way as to cut the lines of force of a magnetic field; in other words, there must be three things, namely, a magnetic field, a system of conductors and motion of those conductors in the magnetic field, the motion being such that the conductors move across and not along the magnetic lines of force.

That part of the dynamo which produces the magnetic field is called a field magnet, while the part carrying the system of moving conductors is called an armature.

The dynamo gives a unidirectional, and not an alternating, voltage at its terminals, but to transfer this voltage to fixed terminals a third part called a commutator is necessary.

10. Найдите в тексте предложения, в которых говорится:

1. о работе первичного двигателя под нагрузкой и на холостом ходу

2. какое явление вызывает появление ЭДС в генераторе постоянного тока

3. о трёх условиях появления ЭДС

4. о назначении индуктора (якоря, коллектора) в генераторе постоянного тока

11. Дайте анализ грамматических явлений, выделенных в тексте.

12. Продолжите список устройств, упоминаемых в тексте

a commutator, a circuit …

13. Задайте разделительный вопрос

Модель: The dynamo gives a unidirectional voltage.

The dynamo gives a unidirectional voltage, doesn’t it?

1. The prime mover has to supply energy.

2. Losses take place in the dynamo at no-load.

3. There is an electromotive force.

4. The conductors move across and not long.

5. The part is called a field magnet.

Unit 5

Construction of the Field Magnet

1. Прочитайте вслух новые слова, познакомьтесь с их русскими эквивалентами. Определите их значения в данных предложениях.

multipolar – многополюсный circular – круглый, круговой yoke (syn. core) – ярмо, станина, сердечник exciting coil – обмотка возбуждения, катушка электромагнита, возбуждающая катушка extension – надставка pole shoe – полюсный башмак, полюсный наконечник an inwardly projecting pole – явный полюс, выступающий внутрь (ярма) полюс cross section – поперечное сечение to wind (wound, wound) – наматы-вать(ся) winding – обмотка former – каркас, шаблон (на котором мотают катушки) frame – станина bobbin – катушка, бобина to withstand – выдерживать, противостоять to wrap – обёртывать, завёртывать tape – лента

The direct-current dynamos are of multipolar construction. The yoke has a circular form. There is an exciting coil on each pole. The extension is called a pole shoe. The circular ring, or the yoke, is provided with inwardly projecting pole. These conductors have a sufficiently large cross section. The coils are wound on a former. The winding consists of small cross section wire. When the former is removed the coil is self-supporting. Sometimes the coil is wound on a bobbin. The coil can withstand various voltages. The coil is wrapped with tape.

2. Прочтите следующие слова. Определите их значение по сходству их корней с соответствующими русскими словами