Винайдення телевізора
Television, as you know is a complex technical process. Its origins go back to the past. We can confidently say that a huge number of people involved in its development and improvement.
Thus, the TV wasn't invented by one person.
The chain of events that led to the invention of television, started in 1817, when the Swedish chemist Jens Berzelius opened chemical element selenium. It was later found that the amount of electric current, is selenium, depends on the amount of light that affect it. This property is called «фотоелектрикою».
In 1875, this discovery helped American inventor, Kerry make the first imperfect television system, for which he has used photovoltaic cells. The subject is focused through a lens unit PV cells in such a way that each element seems to «monitor» the amount of electricity flowing in incandescent lamp. Dim outline of the object, which спроецьований for photovoltaic applications, then appeared on the surface of the filament lamp.
The next step was the invention in 1884 Floors Ніпкоу «deployed image». This was achieved by means of a disk with openings that rotates in front of the photoelectric elements and different disc that rotates in front of the audience. But the principle was the same as that of Kerry.
In 1923 performed the first practical transfer of images by wire, and made it a bird in England and Jenkins in the United States.
Then there was a huge leap in the development of television cameras. Vladimir Zworykin and Phil Farnsworth independently designed the camera, known as «інконоскоп» and «зображально-transmitting tube». Until 1945 both transmitting tubes were replaced with newer.
In modern TV is a so-called «a cathode ray tube». In this tube is the electron gun that scans an image of the screen just as the rays do it in передаючій a television camera, and as a result we see the image.
Of course, this does not explain to you, in detail, exactly how acts TV, but gives you an idea of how many different discoveries were to be realized by different people in different countries, to make possible the current TV.
2. If I study harder, I will pass my exam
b)
1. Our country would be richer if people took care of our environment
2. My house would be more beautiful if I did housework
3. If I were a teacher, I would make my lessons more interesting