Scanning

Listening

7. Listen to the text and answer the questions below.

When does a bipolar junction transistor switch to “on” state?

What is a flip-flop arrangement?

8. Practise your speed reading. Try to be the first to answer these questions.

1) What devices were used in electronic circuits before transistors?

2) Why were scientists looking for alternatives to vacuum tubes?

3) Who invented the transistor?

4) When and where were transistors invented?

5) What is the role of the transistor invention?

6) When was the Noble Prize awarded to the inventors?

Who Invented the Transistor?

If cells are the building blocks of life, transistors are the building blocks of the digital revolution. Without transistors, the technological wonders you use every day – cell phones, computers, cars – would be vastly different, if they existed at all.

Before transistors, product engineers used vacuum tubes and electromechanical switches to complete electrical circuits. Tubes were far from ideal. They had to warm up before they worked (and sometimes overheated when they did), they were unreliable and bulky and they used too much energy. Everything from televisions, to telephone systems, to early computers used these components, but in the years after World War II, scientists were looking for alternatives to vacuum tubes. And they would soon find their answer.

The Bell Telephone System, in particular, needed something better than vacuum tubes to keep its communications systems working. In 1947, Shockley was director of transistor research at Bell Telephone Labs. Brattain was an authority on solid-state physics as well as expert on nature of atomic structure of solids and Bardeen was an electrical engineer and physicist. Within a year, Bardeen and Brittain used the element germanium to create an amplifying circuit, also called a point-contact transistor. Soon afterward, Shockley improved on their idea by developing a junction transistor.

The next year, Bell Labs announced to the world that it had invented working transistors. The original patent name for the first transistor went by this description: Semiconductor amplifier; three-electrode circuit element utilizing semiconductive materials. It was an innocuous-sounding phrase. But this invention allowed scientists and product engineers far greater control over the flow of electricity.

While Bardeen quit Bell Labs to become an academic (he went on to enjoy even more success studying superconductors at the University of Illinois), Brattain stayed for a while before retiring to become a teacher. Shockley set up his own transistor-making company and helped to inspire the modern-day phenomenon that is "Silicon Valley" (the prosperous area around Palo Alto, California where electronics corporations have congregated). Two of his employees, Robert Noyce and Gordon Moore, went on to found Intel, the world's biggest micro-chip manufacturer.

Bardeen, Brattain, and Shockley were briefly reunited a few years later when they shared the world's top science award, the 1956 Nobel Prize in Physics, for their discovery. Their story is a riveting tale of intellectual brilliance battling with petty jealousy and it is well worth reading more about.

So, transistors were invented at Bell Laboratories in New Jersey in 1947 by three brilliant US physicists: John Bardeen (1908–1991), Walter Brattain (1902–1987), and William Shockley (1910–1989). It's no exaggeration that transistors have enabled some of humankind's biggest leaps in technology.

Дата добавления: 2014-11-29