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Контрольное задание № 1 V. B
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Прочитайте текст и выполните упражнения, следующие за ним.
AMPLIFIERS
Amplifier is an electronic device used for increasing the power of a signal. It does it by taking energy from a power supply and controlling the output to match the input signal shape but with larger amplitude. In this sense, an amplifier may be considered as modulating the output of the power supply. There are numerous types of electronic amplifiers specialized to various applications. The basic types of amplifiers are: voltage, current, transconductance and transresistance amplifiers.
Voltage amplifier is the most common type of amplifier. An input voltage is amplified to a large output voltage. The amplifier’s input is high and the output is low.
Current amplifier changes the input current to a larger one. Amplifier’s input impedance is low and output impedance is high.
Transconductance amplifier responds to a changing input voltage by delivering a related changing output current.
Transresistance amplifier responds to a changing input voltage. Sometimes this type of an amplifier is called transimpedance amplifier or current-to-voltage converter.
Until the invention of the transistor in 1947, most practical high-frequency electronic amplifiers were made using thermionic valves. The simplest valve was invented by John Fleming in 1904. He named this valve the diode, as it had two electrodes. The diode conducted electricity in one direction only and was used as a radio detector and a rectifier. In 1906 Lee Forest added the third electrode and invented the first electronic amplifying device, the triode, which he named audion. World War II stimulated dramatic technical progress and advanced the development of the design of amplifier circuits. Beginning in the 1970s, more and more transistors were connected on a single chip creating integrated circuit.
Amplifiers can be specified according to their input and output properties. They have some kind of gain or multiplication factor relating the magnitude of the output signal to the input signal. The gain may be specified as the ratio of output voltage to input voltage (voltage gain), output power to input power (power gain), or some combination of current, voltage and power. The power gain of an amplifier depends on the source and load impedances used as well as its voltage gain. RF amplifier may have its impedances optimized for power transfer. Audio and instrumentation amplifiers are normally employed with amplifier input and output impedances optimized for least loading and highest quality. The quality of an amplifier can be characterized by such specifications like gain, bandwidth, efficiency, linearity, noise, slew rate and rise time.
In most cases an amplifier should be linear, that is the gain should be constant for any combination of input and output signals. If the gain is not constant, e.g. by clipping the output signal at the limits of its capabilities, the output signal will be distorted. Many types of electronic amplifiers are commonly used in radio, television transmitters and receivers, high-fidelity (“hi-fi”) stereo equipment, microcomputers and other electronic digital equipment.
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Задание 1. Дайте русские эквиваленты следующим английским словам и словосочетаниям
Electron- electronic- electronics, signal- signalize, control-controller, amplitude, modulate-modulation-modulator-modulator types, specialize-specialization-specialized, apply-application, active-activity, amplify-amplification-amplifier-audio hi-fi amplifier- transconductance amplifier, transistor, detect-detection-detector-radio detector, triod
Задание 2. Определите по суффиксу, к какой части речи относятся следующие слова:
supply, active, component, including, total, width, application, impedance, delivering, factor, capability, constant, measure.
Задание 3. Найдите в тексте цепочки существительных-определений, состоящих не менее чем из трех компонентов, выделите основное слово, переведите
Задание 4. Укажите недостающие степени сравнения:
Least, most, highest, lower, largest, smallest, larger
Задание 5. Переведите следующие слова и словосочетания:
In this sense, such as, although, some kind of, the same, as well as, ten times greater, much more than, for example, that is, e.g.,.
Задание 6. Запишите глаголы, образованные от следующих существительных, и переведите их:
Specification, consumption, application, impedance, multiplication, combination, conductance, equipment, component.
Задание 7. Укажите прилагательные, от которых образованы следующие существительные:
Stability, ability, width, proportionality, property, capability
Задание 8. Составьте предложения согласно английскому порядку слов
1. Numerous, amplifiers, are, types, there electronic of
2. He, valve, this, diode, named, the.
3. The, conducted, diode, electricity, direction, only, in, one.
Задание 9. Соотнесите русские и английские эквиваленты:
| 1. Electronic device used for increasing the power of a signal | а) Лампа с термокатодом |
| 2. To match the input signal shape | b) Передача энергии |
| 3. Numerous types of electronic amplifiers | с) Входная мощность |
| 4. Input and output properties | d) Коэффициент усиления напряжения |
| 5. The ratio of output voltage to the input voltage | е) Электронные приборы, используемые для повышения мощности сигнала |
| 6.Thermionic valve | f) Полное сопротивление источника |
| 7. Transconductance amplifier | g) Выходная мощность |
| 8. Input power | h) Усилитель активной междуэлектродной проводимости |
| 9. Output power | i) Коэффициент усиления по мощности |
| 10. RF amplifier | j) Радиочастотный усилитель |
| 11. Source impedance | k) Полное сопротивление нагрузки |
| 12. Load impedance | l) Усилитель должен быть линейным |
| 13. Voltage gain | m) Посредством ограничения выходного сигнала |
| 14. Power transfer | n) Сопротивление, оптимизированное для наименьшей нагрузки и самого высокого качества |
| 15. Power gain | о) Для любой комбинации входных и выходных сигналов |
| 16. Impedances optimized for least loading and highest quality | р) Согласовывать форму входного сигнала |
| 17. An amplifier should be linear | q) Свойства входа-выхода |
| 18. For any combination of input and output signals | r) Выходной сигнал будет искажаться |
| 19. By clipping the output signal | s) Многочисленные типы электронных усилителей |
| 20.The output signal will be distorted | t) Отношение напряжения на выходе к напряжению а входе |
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Задание 10. Переведите на русский язык 1, 2, 3 абзацы текста.
Задание 11. Переведите предложения на русский язык, учитывая видо-временную форму английского глагола.
1. Titanium and its alloys are coming out in the commercial field- they have already made quite a name for themselves as structural materials.
2. What scientists will have developed by 2050 is incredible!
3. Scientists have been studying the behavior of various bacteria in space for a long time
4. It is almost impossible to imagine what scientists will be investigating in 50 years’ time?
5. Electronics has been developing at a great speed recently.
6. What fundamental physical laws the physicists will have revised by the end of the 21st century is difficult to predict nowadays.
7. When he started to understand the phenomenon of superconductivity he had been performing numerous experiments for more than 10 years.
8. They will have developed the project by the end of the century.
9. The scientist was working in the laboratory when this breaking news came.
10. After Becquerel had made a number of experiments, he discovered the phenomenon of radioactivity.
11. The scientists are still working at the problem of global warming.
12. We are still learning how to exploit the potential of the integrated circuits by developing new theories and designing new circuits whose performance may yet be improved by another order of magnitude.
13. The number of applications for microprocessors is growing daily in industry, in banking, in power generation and distribution and in telecommunication.
Задание 12. Ответьте на вопросы по тексту
1. What is an amplifier used for?
2. How does an amplifier increase the power of a signal?
3. What are the basic types of amplifiers?
4. When was the simplest valve invented?
5. How many electrodes had this valve?
6. How can amplifiers be specified?
7. What does the power gain of an amplifier depend on?
8. In what cases an amplifier should be linear?
9. When will the output signal be distorted?
10. Where are electronic amplifiers commonly used?
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