Switching 1. Telephone exchanges.

On March 10^th 1876, in Boston USA, Alexander Graham Bell spoke

the first recognizable words over what was certainly his most famous invention, the telephone. “Mr. Watson, come here. I want you,” he called out to an astonished assistant.

It quickly became necessary to link up people using the new invention. This was done through the telephone exchange. In the first simple exchanges, all calls were handled manually by the operator. Using the switchboard in front of her, she plugged the line of the subscriber calling her into the line of the subscriber being asked for.

The idea of an automatic exchange was soon suggested. In 1892, three years after patenting his ideas, Almon B. Strowger saw his system installed at La Porte, Indiana. Strowger, an undertaker from Kansas City, found his business was becoming less and less profitable because the operator always connected calls intended for him to other undertakers.

Strowger’s automatic exchange underwent several modifications over the next fifty years, but the principle has remained the same ever since. It is known as the “step- by- step” system and there are still thousands of Strowger exchanges in service throughout the world today.

The next generation of exchanges was first developed in Sweden. Crossbar exchanges, as they are called, consist of series of vertically and horizontally crossed bars. For the first time a common control system was used. This made crossbar exchanges cheaper than Strowger, for each selector could now carry up to ten calls. They were not as noisy as Strowger, either. These exchanges are electro- mechanically operated, using electromagnets.

In 1948, the invention of the transistor at Bell Telephone Laboratories led to a revolution in electronics and to the creation of semi- electronic telephone exchanges.

The old mechanical and electromechanical exchanges have now begun to disappear and since the 1970s they have started to be replaced by exchanges built around electronic components. The latest digital switching centres have several advantages over other types of exchange for they provide: a substantial reduction in equipment cost; a large reduction in equipment size; shorter procurement times; shorter installation and commissioning times; greater reliability and reduced running costs; new services for the customer; and new facilities for the administration.

 

 

Task 7. Ответьте на вопросы по тексту.

 

1. What do Americans call a telephone exchange?
2. Who invented the telephone? When and where?
3. What did the first operator do?
4. Why did Strowger invent the automatic telephone exchange?
5. What advantages does crossbar exchange offer over Strowger?
6. What important development took place in 1948?
7. What are mechanical and electromechanical exchanges being replaced by?

 

Task 8. Переведите на английский язык следующие предложения, используя Present/ Past Simple.

 

1. Она подсоединила линию этого абонента к линии мистера Смита.
2. Идея автоматической станции была запатентована в 1889 году.
3. Мы используем электромагниты на координатных станциях.
4. Они подвергли эту систему некоторым изменениям?
5. Где были развиты первые координатные станции?
6. Это изобретение сделало его бизнес прибыльным.
7. Декадно-шаговая система известна по всему миру.
8. Они не устанавливали эту систему в нашем городе.

 

Task 9. Подставьте в пропуски местоимения all или both, переведите предложения.

Местоиме- ние	функция
Определение к существитель- ному	Определение к местоимению	подлежащее	дополнение	Именная часть сказуемого
All-все, вся, весь	Allthe pupils are present. - Все ученики присутствуют.	We allknow it. - Мы все знаем это.	Allis ready.- Все готово.	I know all.- Я знаю все.	It is all.- Это все.
Both-оба,обе	Bothbrothers live here.- Оба брата живут здесь.	We bothlike it.- Мы оба это любим.	Bothare correct.- Оба правильные.	I take both.- Я беру оба.	They are bothhere.- Они оба здесь.

 

1. A steel magnet and a diaphragm, they _____ are important parts of the receiver.
2. _____ telephone sets need protection.
3. We replaced _____ equipment last week.
4. _____ people need communication.
5. In that region there are _____ exchanges: electromechanical and digital exchanges.

 

Unit 4