План-конспект урока английского языка на тему «Вакуумная трубка».

Тема «Контрольный перевод технического текста с зарисовкой прибора по описанию и ответами на вопросы. Вакуумная трубка».

Преподаватель Климова Ирина Владимировна.

Тип урока: комбинированный.

Цели урока.

• Пополнение словарного запаса из области «Техническая терминология»

• Совершенствование навыков технического перевода.

• Развитие умения логически верно, аргументированно строить устную речь, связанную с тематикой технической направленности.

Оснащение. Карточки с раздаточным материалом

Ход урока.

I.Повторение выражений из инструкции.

1. Continues to define the state of the art in this field

2. Related products for every amateur need

3. Congratulations on selecting

4. The IT-100 provides

5. It will match the amazing range of antennas

6. Including…

7. The IT-100 is similar to previous…

8. But is specially engineered to integrate with…

9. Takes advantage of…

10. To simplify

11. Is powered by…

12. Are used…

13. Latching

14. Instantaneous

15. Controlled from…

16. Works with…

17. Is rated at 125 maximum power

18. Power level that significantly exceed specifications will definitely damage or destroy your device

19. If your tuner fails during overload, it could also damage your transmitter or transreceiver

20. Never install…

21. Always follow this antenna safety rule

22. It is a quality precision instrument that will give you many years of outstanding service

23. Take a few minutes to get to know it

24. The device is designed specifically for the use with…

25. The operation is performed when…

26. Is powered directly from the radio interface cable

Составление предложений с этими выражениями.

II.Работа с текстом « Описание вакуумной трубки».

1. In electronics, a vacuum tube, an electron tube, or just a tube , or valve  is a device that controls electric current between electrodes in an evacuated container.

2. Vacuum tubes mostly rely on thermionic emission of electrons from a hot filament or a cathode heated by the filament.

3. The simplest vacuum tube, the diode, contains only a heater, a heated electron-emitting cathode, and a plate (anode).

4. Adding one or more control grids within the tube allows the current between the cathode and anode to be controlled by the voltage on the grid or grids. 

5. Tubes with grids can be used for many purposes, including amplification, rectification, switching, oscillation, and display.

6. Invented in 1904 by John Ambrose Fleming, vacuum tubes were a basic component for electronics throughout the first half of the twentieth century, which saw the diffusion of radio, television, radar, sound reinforcement, sound recording and reproduction, large telephone networks, analog and digital computers, and industrial process control.

Tubes have different functions, such as cathode ray tubes which create a beam of electrons for display purposes (such as the television picture tube) in addition to more specialized functions such as electron microscopy and electron beam lithography. X-ray tubes are also vacuum tubes. Phototubes and photomultipliers rely on electron flow through a vacuum, though in those cases electron emission from the cathode depends on energy from photons rather than thermionic emission.

Diode: electrons from the hot cathode Triode: voltage applied to the grid controls plate current current .

flow towards the positive anode,

but not vice versa

A vacuum tube consists of two or more electrodes in a vacuum inside an airtight enclosure. Most tubes have glass envelopes with a glass-to-metal seal based on kovar sealable borosilicate glasses, though ceramic and metal envelopes (atop insulating bases) have been used. The electrodes are attached to leads which pass through the envelope via an airtight seal.

Most modern tubes are "indirectly heated" by a "heater" element inside a metal tube that is the cathode. The heater is electrically isolated from the surrounding cathode and simply serves to heat the cathode sufficiently for thermionic emission of electrons. The electrical isolation allows all the tubes' heaters to be supplied from a common circuit (which can be AC without inducing hum) while allowing the cathodes in different tubes to operate at different voltages. 

Triode symbol. From top to bottom: plate (anode), control grid, cathode, heater (filament)

Tetrode symbol. From top to bottom: plate (anode), screen grid, control grid, cathode, heater (filament)

General Electric Company Pliotron, Chemical Heritage Foundation

To combat the stability problems and limited voltage gain due to the Miller effect, the physicist Walter H. Schottky invented the tetrode tube in 1919. He showed that the addition of a second grid, located between the control grid and the plate (anode), known as the screen grid, could solve these problems. ("Screen" in this case refers to electrical "screening" or shielding, not physical construction: all "grid" electrodes in between the cathode and plate are "screens" of some sort rather than solid electrodes since they must allow for the passage of electrons directly from the cathode to the plate). A positive voltage slightly lower than the plate (anode) voltage was applied to it, and was bypassed (for high frequencies) to ground with a capacitor. This arrangement decoupled the anode and the control grid, essentially eliminating the Miller capacitance and its associated problems. Consequently, higher voltage gains from a single tube became possible, reducing the number of tubes required in many circuits. This two-grid tube is called a tetrode, meaning four active electrodes, and was common by 1926.

6L6 tubes in glass envelopes Metal-cased tubes with octal bases High power GS-9B triode transmitting tube with heat sink at bottom.

Most modern tubes have glass envelopes, but metal, fused quartz (silica) and ceramic have also been used. Metal and ceramic are used almost exclusively for power tubes above 2 kW dissipation. The nuvistor was a modern receiving tube using a very small metal and ceramic package.

The internal elements of tubes have always been connected to external circuitry via pins at their base which plug into a socket. Subminiature tubes were produced using wire leads rather than sockets, however these were restricted to rather specialized applications. In addition to the connections at the base of the tube, many early triodes connected the grid using a metal cap at the top of the tube; this reduces stray capacitance between the grid and the plate leads. Tube caps were also used for the plate (anode) connection, particularly in transmitting tubes and tubes using a very high plate voltage.

Some special-purpose tubes are constructed with particular gases in the envelope. For instance, voltage-regulator tubes contain various inert gases such as argon, helium or neon, which will ionize at predictable voltages. The thyratron is a special-purpose tube filled with low-pressure gas or mercury vapor. Like vacuum tubes, it contains a hot cathode and an anode, but also a control electrode which behaves somewhat like the grid of a triode. When the control electrode starts conduction, the gas ionizes, after which the control electrode can no longer stop the current; the tube "latches" into conduction. Removing anode (plate) voltage lets the gas de-ionize, restoring its non-conductive state.

Some thyratrons can carry large currents for their physical size. A cold-cathode version of the thyratron, which uses a pool of mercury for its cathode, is called an ignitron; some can switch thousands of amperes. Thyratrons containing hydrogen have a very consistent time delay between their turn-on pulse and full conduction; they behave much like modern silicon-controlled rectifiers, also called thyristors due to their functional similarity to thyratrons. Hydrogen thyratrons have long been used in radar transmitters.

An extremely specialized tube is the krytron, which is used for extremely precise and rapid high-voltage switching. Krytrons with certain specifications are suitable to initiate the precise sequence of detonations used to set off a nuclear weapon, and are heavily controlled at an international level.

X-ray tubes are used in medical imaging among other uses. X-ray tubes used for continuous-duty operation in fluoroscopy and CT imaging equipment may use a focused cathode and a rotating anode to dissipate the large amounts of heat thereby generated. These are housed in an oil-filled aluminium housing to provide cooling.

The photomultiplier tube is an extremely sensitive detector of light, which uses the photoelectric effect and secondary emission, rather than thermionic emission, to generate and amplify electrical signals. Nuclear medicine imaging equipment and liquid scintillation counters use photomultiplier tube arrays to detect low-intensity scintillation due to ionizing radiation.

Выполнение заданий по тексту.

1.Выписать выражения, соответствующие следующим…

1. Tubes with grids can be used for many purposes, including 

2. which create a beam of electrons for display purposes

3. filament  

4. sound reinforcement,

5. amplification, rectification, switching, oscillation,

6. external circuitry

7. special-purpose tubes

8. voltage-regulator tubes contain

9. which behaves somewhat like the grid of a triode.

10. Thyratrons containing hydrogen have a very consistent time delay

11. An extremely specialized tube is

12. are suitable to initiate the precise sequence of detonations

13. and are heavily controlled at an international level.

14. to dissipate the large amounts of heat thereby generated.

15. to generate and amplify electrical signals.

1. Трубки с решетками могут быть использованы в различных целях, включая

2. Что создает луч электронов выполняющих функции показа

3. нить волокно волосок

4. усиление звука

5. усиление, выпрямление, переключение, колебание,

6. внешняя схема

7. трубки специального назначения

8. трубки для контроля напряжения включают

9. который работает по тому же принципу что и триод

10. Тиратроны, содержащие водород, имеют очень последовательную временную задержку

11. Чрезвычайно специализированная трубка

12. подходят для запуска точной последовательности детонаций

13. строго контролируются на международном уровне

14. для рассеивания большого количества созданного при этом тепла

15. для создания и усиления электрических сигналов

2.Найдите окончания следующим выражениям…

1. Vacuum tubes mostly rely on thermionic emission of electrons from a hot filament or a cathode heated by the filament.

2. as cathode ray tubes which create a beam of electrons for display purposes

3. A vacuum tube consists of two or more electrodes in a vacuum inside an airtight enclosure.

4. The electrodes are attached to leads which pass through the envelope via an airtight seal.

5. The heater is electrically isolated from the surrounding cathode and simply serves to heat the cathode sufficiently for thermionic emission of electrons.

6. The electrical isolation allows all the tubes' heaters to be supplied from a common circuit

1. electron emission from the cathode depends on energy from photons rather than thermionic emission

2. A positive voltage slightly lower than the plate (anode) voltage was applied to it, and was bypassed (for high frequencies) to ground with a capacitor.

3. The internal elements of tubes have always been connected to external circuitry via pins at their base which plug into a socket.

4. High-power tubes such as transmitting tubes have packages designed more to enhance heat transfer

5. . When the control electrode starts conduction, the gas ionizes, after which the control electrode can no longer stop the current;

6. The thyratron is a special-purpose tube filled with low-pressure gas or mercury vapor.

7. the krytron, which is used for extremely precise and rapid high-voltage switching.

8. X-ray tubes used for continuous-duty operation in fluoroscopy and CT imagingequipment

1. Vacuum tubes mostly rely on …….

2. cathode ray tubes  create ….

3. A vacuum tube consists of ….

4. The electrodes are attached to …

5. The heater is electrically isolated from …..

6. The electrical isolation allows all the tubes' heaters ….

1. electron emission from the cathode depends …

2. A positive voltage slightly lower than …

3. The internal elements of tubes have always been connected to ….

4. High-power tubes such as transmitting tubes have packages designed more …

5. When the control electrode starts conduction…..

6. The thyratron is a special-purpose tube …

7. .krytron is used for …

8. X-ray tubes are used for…

3. Напишите что сказано в тексте о…

1. Vacuum tube

2. Diode

3. Cathode ray tube

4. Coverage of a vacuum tube

5. Tetrode tube

6. The internal elements of tube

7. Thyratron

8. Krytron

9. x-ray tube

10. photomultiplier

1. In electronics, a vacuum tube, an electron tube, or just a tube , or valve  is a device that controls electric current between electrodes in an evacuated container.

2. The simplest vacuum tube, the diode, contains only a heater, a heated electron-emitting cathode, and a plate (anode).

1. cathode ray tubes which create a beam of electrons for display purposes (such as the television picture tube) in addition to more specialized functions such as electron microscopy and electron beam lithography. X-ray tubes are also vacuum

1. Most tubes have glass envelopes with a glass-to-metal seal based on kovar sealable borosilicate glasses, though ceramic and metal envelopes (atop insulating bases) have been used.

2. This two-grid tube is called a tetrode, meaning four active electrodes, and was common by 1926.

3. Subminiature tubes were produced using wire leads rather than sockets, however these were restricted to rather specialized applications. In addition to the connections at the base of the tube, many early triodes connected the grid using a metal cap at the top of the tube; this reduces stray capacitance between the grid and the plate leads.

4. The thyratron is a special-purpose tube filled with low-pressure gas or mercury vapor. Like vacuum tubes, it contains a hot cathode and an anode, but also a control electrode which behaves somewhat like the grid of a triode.

5. An extremely specialized tube is the krytron, which is used for extremely precise and rapid high-voltage switching. Krytrons with certain specifications are suitable to initiate the precise sequence of detonations used to set off a nuclear weapon, and are heavily controlled at an international level.

6. X-ray tubes are used in medical imaging among other uses. X-ray tubes used for continuous-duty operation in fluoroscopy and CT imaging

7. The photomultiplier tube is an extremely sensitive detector of light, which uses the photoelectric effect and secondary emission, rather than thermionic emission, to generate and amplify electrical signals.

III.Подведение итогов урока и задание на дом. Подготовить сообщение об электронном приборе.