Добавил:
Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
методичка 5 курс (правильная).doc
Скачиваний:
9
Добавлен:
11.11.2019
Размер:
304.13 Кб
Скачать

1. Put the words in the right order to make a sentence:

1. Infra-Red, light, particular, actually, is, normal, a, with, colour. 2. The, the, a, key, wakes, when, up, to, transmit, is, appropriate, IR, command, only, processor, pressed. 3. A, or, video, digital, can, "see", the, Infra-Red, camera, camera, photo, light. 4. A, be, transistor, the, circuit, used, can, drive, to, simple, LED. 5. Power, are, very, low, transmitters, microcontrollers, used, IR, in. 6. A, in, of, this, a, across, pulses, constant, resistor, magnitude, constant, resistor, amplitude, current, constant, results. 7. The, will, as, drops, the, well, battery, as, current, LED, voltage, decrease, through. 8. Power, of, maximum, the, average, the, though, dissipation, LED, value, not, the, should, exceed.

2. Fill in the blanks with the following words:

Light, modulation, battery, power, chips, camera, sheet, resistor, command, crystals

1. The processor wakes up to transmit the appropriate IR … only when a key is pressed. 2. Infra-Red actually is normal …with a particular colour. 3. The transmitter usually is a … powered handset. 4. A video … or digital photo camera can "see" the Infra-Red light. 5. Very low … microcontrollers are used in IR transmitters. 6. This constant amplitude across a constant … results in current pulses of a constant magnitude. 7. All these parameters can be found in the LED’s data … . 8. Quartz … are seldom used in such handsets. 9. … is the answer to make our signal stand out above the noise. 10. Many … are designed to be used as IR transmitters.

3. Complete the following sentences using active vocabulary:

1. The cheapest way to remotely control a device … 2. With modulation we make the IR light source blink in … 3. LED currents can be that high because … 4. … only when a key is pressed. 5. Quartz crystals are seldom used in … 6. A transistor with a suitable HFE and switching speed should be … . 7. ... quite cheap, thus making it ideal for us hobbyists to use IR control for our own projects. 8. Although we humans can't see the Infra-Red light emitted from a remote control doesn't … . 9. … are commonly used in consumer electronics. 10. Ceramic resonators are much more suitable here, because they … .

4. Say if the following statements are true or false:

1. Humans can see the Infra-Red light emitted from a remote control. 2. Wave length of 950nm is above the visible spectrum. 3. Humans can see a particular colour.4. A video camera or digital photo camera can’t "see" the Infra-Red light. 5. There is not source of Infra-Red light. 6. Everything that radiates ice, also radiates Infra-Red light. 7. A simple transistor circuit can’t be used to drive the LED. 8. Average power dissipation of the LED should not exceed the maximum value though. 9. A trade-off should be made between LED parameters, battery lifetime and maximum control distance. 10. A 'mark' is then automatically represented by a high level.

5. Answer the following questions:

1. What is normal light with a particular colour? 2. What device can be used to drive the LED? 3. How many diodes will limit the pulses on the base of the transistor? 4. Does the processor wake up to transmit the appropriate IR command only when a key is pressed? 5. What is the default signal, which is the off state in the transmitter case?

6. Why can't humans see a particular colour? 7. What radiates Infra-Red light? 8. Is 1.1V or 1.3V nominal voltage drop over an IR LED? 9. Can the resistor values simply be calculated using Ohm's law? 10. What is the answer to make our signal stand out above the noise?