Transistors in computers

WHO INVENTED THE TRANSISTROR?

Grammar

1. Study the sentences below and pay attention to the underlined verb forms in italics.

Your brain contains around 100 billion cells called neurons.

Computers contain billions of miniature brain cells as well.

But what are they – and how do they work?

A transistor is really simple and really complex.

The small current switches on the larger one.

The most advanced transistors work by controlling the movements of individual electrons.

Answer the following questions:

5) What are these verb forms?

6) is, are. What verb has such forms?

7) contains, switches. What do these verb forms have in common?

8) contain, work. Are these verb forms similar?

9) What tense are these verb forms in?

It is the Present Indefinite or Present Simple Tense.

2. How do we form sentences in the Present Indefinite? Complete the table.

Positive	Negative	Interrogative
I, you, we, they + Verb. He, she, it +Verb + (e)s	Subject + do + not + Verb. Subject + does + not + Verb	Do+ Subject+Verb? Does + Subject + Verb?
I teach English every day. You He studies every day. She It We They	I do not teach every day.   He does not study every day.	Do I teach every day?   Does he study every day?

 

3. So, now we can form the Present Indefinite. But when do we use the Present Indefinite? Study the following table and give your own examples.

Actions happen…	Examples
Repeated actions, habits, routines: every morning / evening / day / night every week / month / year usually always never frequently/often seldom/rarely sometimes/occasionally/ from time to time nowadays	· We get up at 8 o’clock every morning. · Mary’s father reads newspapers every evening. · He usually goes home after work. · She always forgets her purse. · I never drink milk. · My friend often draws nice posters. · They rarely visit their parents. · Susan sometimes meets with her friends after school. · Nowadays all electronic devices use semiconductors.
Facts, generalizations, universal truths	· Electrons have negative charges. · Silicon is a semiconductor. · Water boils at 100 degrees. · The Earth goes around the Sun. · Transistors work as amplifiers and switches.
Fixed arrangements, timetables	· The meeting starts at 4 p.m. · The train leaves at 10 a.m. · When does the plane take off? · The course starts in April.
With non-continuous verbs: be, believe, belong, hate, hear, like, love, mean, prefer, remain, realize, see, seem, smell, think, understand, want, wish	· I understand English. · You are students. · She believes in God. · He loves and hates her. · We know this rule. · They like everything about electronics.

 

Reading

4. Read the text, find the sentences in the Present Indefinite Tense and explain its usage.

Transistors are devices that control the movement of electrons, and consequently, electricity. They work something like a water faucet – they do not only start and stop the flow of a current, but they also control the amount of the current. With electricity, transistors can both switch or amplify electronic signals, letting you control current moving through a circuit board with precision.

In a computer chip, the transistors aren't isolated, individual components. They're part of what's called an integrated circuit (also known as a microchip), in which many transistors work in concert to help the computer complete calculations. An integrated circuit is one piece of semiconductor material loaded with transistors and other electronic components.

Computers use those currents in tandem with Boolean algebra to make simple decisions. With many transistors, a computer can make many simple decisions very quickly, and thus perform complex calculations very quickly, too.

Computers need millions or even billions of transistors to complete tasks. Thanks to the reliability and incredibly small size of individual transistors, which are much smaller than the diameter of a single human hair, engineers can pack an unfathomable number of transistors into a wide array of computer and computer-related products.

5. Complete this description of how transistors in logic gates work, using the correct form of the verbs in the box.

be work give help make need have compare

 

In practice, you (1) …… not ……… to know any of this stuff about electrons and holes unless you're going to design computer chips for a living! All you need to know is that a transistor (2) …………. like an amplifier or a switch, using a small current to switch on a larger one. But there's one other thing to know: how (3) ……..all this………computers store information and make decisions?

We can put a few transistor switches together to make something called a logic gate, which (4) …………….several input currents and (5) …………a different output as a result. Logic gates let computers make very simple decisions using a mathematical technique called Boolean algebra. Your brain (6) ………… decisions the same way. For example, using "inputs" (things you know) about the weather and what you have in your hallway, you can make a decision like this: "If it's raining AND I (7) …………an umbrella, I will go to the shops". That's an example of Boolean algebra using what's called an AND operator. You can make similar decisions with other operators. "If it's windy OR it's snowing, then I will put on a coat" is an example of using an OR operator. Or how about "If it's raining AND I have an umbrella OR I have a coat then it's okay to go out". Using AND, OR, and other operators called NOR, NOT, and NAND, computers can add up or compare binary numbers. That idea (8) ……………the foundation stone of computer programs: the logical series of instructions that make computers do things.

6. Make your own positive, negative and interrogative sentences about transistors in the Present Indefinite Tense.

Listening

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

Normally, a bipolar junction transistor is "off" when there is no base current and switches to "on" when the base current flows. That means it takes an electric current to switch the transistor on or off. But transistors like this can be hooked up with logic gates so their output connections feed back into their inputs. The transistor then stays on even when the base current is removed. Each time a new base current flows, the transistor "flips" on or off. It remains in one of those stable states (either on or off) until another current comes along and flips it the other way. This kind of arrangement is known as a flip-flop and it turns a transistor into a simple memory device that stores a zero (when it's off) or a one (when it's on). Flip-flops are the basic technology behind computer memory chips.

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

What is a flip-flop arrangement?

Scanning

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?