English for Specific Purposes

Electronic Engineering 103

 

SPECIALIST READING A: Transistor Jubilee

 

11. Scan the text and match the headings (a – j) with the paragraphs (1 – 9). There is one heading you will not need to use.

 

A) Modern microchips

B) Quality-price ratio

C) Semiconductors

D) The 'magic' a transistor performs

E) Transistor functions

12. Now study the text to find this information and write sentences you have found in the gaps:

 

_______________________

 

ability to control _______________________

 

semiconductance _______________________

 

_______________________

 

efforts to find a _______________________

 

better amplifier _______________________

 

_______________________ invisible electronic _______________________

 

device _______________________

 

_______________________

 

logic gates _______________________

 

_______________________

 

_______________________ quadraphonic hi- _______________________

 

fidelity sound _______________________

 

_______________________

 

reliability of _______________________

 

transistors in IC _______________________

 

_______________________

 

sophisticated _______________________

 

layering techniques _______________________

 

transistor can _______________________

 

control a strong _______________________

 

current from _______________________

 

another circuit

 

 

Invented at Bell Laboratories in 1947, the transistor resulted from efforts to find a better amplifier and a replacement for mechanical relays. The vacuum tube amplified music and voice during the first half of the 20th century, and it made long-distance calling practical. But it consumed lots of power, operated hot and burned out rapidly. Cheaper to make than the vacuum tube and far more reliable, the transistor cut the cost and improved the quality of phone service.

1. ______________________________

 

The transistor has many applications, but only two basic functions: switching and modulation. Transistor controls current flow, be it through a lamp or a device to be activated. Both acts as a switch-on/off-and as a modulator/amplifier. The important difference is that the "hand" operating the transistor is millions of times fast. And it's attached to another electrical source – a radio signal in an antenna, for example, a voice in a microphone, or data signal in a computer system, or even another transistor.

2. ______________________________

Transistors are made of semi-conductors such as

 

silicon and gallium arsenide. These materials carry electricity moderately well – not well enough to be called a conductor, like copper wires; not badly enough to be called an insulator, like a piece of glass. Hence their name is semiconductor. The 'magic' a transistor performs is in its ability to control its own semiconductance, acting like a conductor when needed, or as an insulator when that is needed.

3. ______________________________

Semiconductors differ in the way they act

 

electrically. Putting a thin piece of semiconductor of one type between two slices of another type has startling results: a little current in the central slice is able to control the flow of the current between the other two. That little current in the middle slice is the juice that is supplied by an antenna or another transistor for example. Even when the input current is weak, as from a radio signal that's traveled a great distance, the transistor can control a strong current from another circuit through itself. In effect, the current through the 'output side' of the transistor mimics the behavior of the current through the 'input side'. The result is a strong, amplified version of the weak radio signal.