Electronic TV

The first television apparels were radios with a device that consisted of a neon tube with a mechanical rotative disk (disk of Nipkow) that produced a red image of the size of a postal stamp. The first service of high definition appeared in Germany in Março of 1935, but it was just available in 22 public rooms. One of the first great transmissions went to of the Olympic Games of 1936, in Berlin. The use of television increased vastly after Second World War due to the technological progresses appeared with the war and to the available additional income (apparels of TV in the thirties cost the equivalent the US$ 7000 current (2001) and there was little available programming).
An ideal pass-low filter eliminates all the frequencies completely above the court frequency, while it allows that the frequencies below this strip pass unaffected. The transition area in the practical filters doesn't exist. A filter passes low ideal it can be obtained mathematically (theoretically) multiplying the sign for the rectangular function in the domain of the frequency or making the convolução with a sincronização function in the domain of the time.
Díodos termiônicos, is electronic valves of simplified construction, initially built by White Thomas Edison before the invention of the incandescent lamp.
The operational amplifier received this name because he had been projected initially to accomplish mathematical operations using the voltage as an analogy of another amount. This is the base of the analog computers where the amp ops was used to accomplish the basic mathematical operations (addition, subtraction, integration, differentiation, and other).
In spite of many they think of the osciloscópio as an instrument inside of a box, a new osciloscópio " type is appearing, which consists of an external analogical-digital conversor connected to a PC that provides the display, control interface, storage in disk, net and a lot of times the electric feeding.
Material supercondutores in temperatures a lot drops have resistance zero. Insulating (such as air, diamond, or other materials no-drivers) they can have extremely high resistance (but not infinite), but they fail and they admit that happens a great current flow sufficiently under tensions discharges.
The Jar of Leyden, first capacitor form, it had been invented in the University of Leiden, in Holland. It was a glass jar covered with metal. The covering intern was connected to a vareta that leaves the jar and I/you/he/she finished in a metal ball.
The microprocessor was invented by Intel in 1971 to assist a Japanese maker of calculators that needed a special integrated circuit.
When any device type is had where there is the performance of a certain physical phenomenon in correlation with other, interagindo, modifying, measuring, there it is the electronics.
Since the beginning of the twentieth century to its half, the valve termoiônica reigned absolute, when in the half of the century, in 1948, to giant in telecommunications Bell Telephone, it developed a device that was simply minuscule in comparison to the valve termoiônica. It was the first transistor. There we were beginning the era of the semiconductor.
The Electronics (Electrónica in Portugal) it is a branch of the physics where you/they are studied the phenomenons of the elementary electric loads, the properties and behavior, of the elétrons, fótons, elementary particles and waves eletromagnéticas This portal intends to gather information related with the electronics and its ramifications. The transistor was invented in Bell Telephone Laboratories in December of 1947 (and not in 1948 as it is frequently said) for Bardeen and Brattain, and initially demonstrated on December 23, 1947 by John Bardeen, Walter Houser Brattain, and William Bradford Shockley, that were laureate with the prize Nobel of the Physics in 1956.
Butterworth is the only filter that maintains the same format for higher orders (even so with a steeper inclination in the attenuated band) while other varieties of filters (Bessel, Chebyshev, elliptic) they possess different formats for higher orders.

Plasm Display

Plasm Displays is devices based on the technology of plasm panels (PDP, Shapes Display Panel), that went aprimorada in to last decade tends in view the market of television of high definition (HDTV). Plasm screens are not used now in video cameras, in these screens of the types are only used CRT and LCD. Plasm Displays is totally plans, they possess high resolution, with exceptional reproduction of colors and they are usually manufactured in screen proportions different from the found in CRTs, generally 16:9 (widescreen), proportion this of image defined as pattern for HDTV. They are also fine panels, as well as the one of the type LCD, occupying little space, once it is not necessary any volume behind the same, as in the apparels of the type CRT (that need of that volume for the elétrons canyons).
Plasm Displays uses gaseous substances (xenon and neon) contained in minuscule cells, that they act as microscopic fluorescent lamps, emitting light to the they receive electric energy. Each cell is covered in its base it interns for a substance (match) that emits light when being stimulated by some radiation type, as the elétrons bunch (in CRT) or the ultraviolet radiation (as in him plasm cell). This ultraviolet radiation is liberated by the gases contained in the cell when the same ones receive electricity. Therefore, unlike the panel of the type LCD for use in displays, the plasm panel emits own light and he/she doesn't need illumination for trás(backlight).
The cells in a plasm display are obtained in a head office of thousands of points (a screen with diagonal measuring 106 cm can possess 1 million cells). The match that recovers internamente each cell is colored, in 3 types of colors, red, green and blue, the basic colors of the system RGB. Each group of 3 of those cells emtindo lights in different colors represents a pixel of the image. Being varied the intensity of the applied electric current the certain cell is also varied the intensity of its shine; with that it is possible to dose the amount of light emitted in each one of the 3 cells of the pixel, being obtained with that whole the necessary colors to represent a certain image.
The microprocessor associated to the panel sends electric energy individually to each cell, making this thousands of times a second, cell the cell to create the image. In fact, the video sign is decoded by the processor that ' he/she draws ' the lines on the way cells similar to the one that happen in CRT.
The cells don't necessarily coincide with the pixels they be she represented in the image. And to represent a pixel for several cells is better than to have the size of the largest cell than the one of the pixel - he/she gets lost in resolution.
Fujitsu was the first company to market plasm screens in 1997, developed using technology maid initially for IBM 25 years before.
Unlike the displays LCD, that possess angle of inferior vision to the of CRT, the plasm displays still possesses vision angle larger than the one of CRTs (160 degrees). One of the reasons is due to the fact of each cell to be lit up individually (in LCD a back general illumination exists). This fact also checks great shine to the image and it facilitates the making of plane screens with larger dimensions than the one of LCD. With relationship to the quality of the image, the same is very close to the one of the best apparels of the type CRT. In he/she Practices it Plasm it is the state of the matter where atoms are ionized when we increased energy, the plasm monitor is a plane and light surface, covered with millions of teeny glass bubbles. Each bubble contains a substance type gas, the plasm, that has a match layer. Think of those bubbles as PIXELS. Now, think of each pixel-bubble as tends three sub-pixels - 1 red, 1 green and 1 blue. Then, when it is necessary to show an image sign (RGB or Video), a current electric controlled digitalmente flows through the plane screen, doing with that the plasm (the substance type gas) it designates bubbles to expel the ultraviolet rays. The light caused by this reaction acts in the match layer doing with that this shines in the appropriate color. We have like this millions of bubbles RGB that shining individually produces a beautiful rich image in colors. Love to the first view TO THE first view, is the paradise. Fantastic images, vibrant colors, perfect lines. The one that the current and future buyers don't know is that, a lot of times, the plasm TV can become a headache and not always it is the type more indicated for its profile. The complaints on defects fill the technical forums in the Internet and the defense associations to the consumer they alert for the lack of information on the part of lojistas and makers.
It alerts The advantages of the very visible TV of healthy plasm. Giant screens, design caprichado and vibrant colors. The disadvantages, even so, difficultly they are to the exhibition and they are hardly ever correctly informed for the salespersons or makers. Who buys a plasm TV, it is not generally knowing about two technical restrictions and impeditivas that can remove the whole grace of the apparel and to place in check the investment.
First restrictions techniques: that pretty and perfect image that you see at the stores, he/she won't repeat at home, to not to be in special conditions. As: if you think can be glued per hours I entrust it sells TV, it is good to seek another amusement. To depend of the type of program televisivo, film or game, the screen of the plasm TV can be burned (spotted) after hours followed with stopped images, causing it called burn-in " effect and marking the screen in a way discreet.
Perfect image? it depends due to the own technology in itself, the plasm TV is molded to exhibit in the screen that only has of best when the sign is digital. In Brazil, the programs of the TV in the open channels arrive in analogical sign. When attending the channels opened in the plasm apparel, you will see scratched out, granulated and an image perceptibly inferior, sometimes worse than in its old TV common of 20 inches. To revert the problem, the option it would be to attend everything with TV for signature (Sky, DirecTV etc.), but, even so, there is not warranty that all the channels are digital. In the films in DVD, that are digital, there is not problem and the image is truly good.
Headache that is removing the buyers of the serious is the burn-in effect, when a static image burns the screen and he/she leaves a stain. Practical example: a soccer game with the logomarca of the channel being exhibited during the whole departure, stop, without moving. A lot of times, after the game, it is easy to notice that that local one was spotted.
Be informed and care with the salespersons Taking in consideration that the plasm TV is rectangular (format widescreen 16:9) and most of the programming is squared (standard format, 4:3) you will see two black tarjas beside the image. Those tarjas, after more or less two hours, they can stain the screen in a definitive way. To avoid that, a solution only exists: to force the reception for the format widescreen, deforming the image and causing visual desconforto. The omission of the information begins at the stores. When researching prices in the stores, the obvious event is to be amazed with the exhibited perfect image. The problem begins when the consumer asks information. In general, the store reviews everything of good on the plasm, without entering in details on the dangers of staining the screen and the low quality of the image when attending open channels.
Most of the salespersons at least knows how to explain, concretely, as it happens the stain and like her it can be avoided in the practice. In some situations, the lojistas explains that the " most recent models don't possess that burn-in problem, because the technology is better ". The truth is that the problem exists, and it is recognized officially by all the makers of plasm TVs and to today total solution doesn't exist.
Some makers of the TVs guarantee that the new models don't possess the problem, for they be of new generation, with resources anti-burn in. However, in the warranty, they don't specify. In the manual, the information are also superficial.
In agreement with the manager of products of LG, Fernanda Summa, some new models possess resources to liven up the burn-in. " The plasm has a restriction of the own technology of not leaving an image static a lot of time in the screen, as the lateral " black tarjas, it explains. She thinks " who buys like this a TV, he/she has to be prepared to use the format widescreen, even if it deforms a little the quality of the image in the open channels. But for films in DVD, the image is perfect ", it guarantees. The manager of logistics of Plasmashop, Thiago Sato, confirms that " unhappily, whole you shape them they are subject and most of the buyers doesn't make idea of the problems to that they happen.
The consumer's right lawyer Maíra Feltrin, of the Institute of Defense of the Consumer (IDEC), it explains that only the fact of the consumer not to be explained correctly about the restrictions they are enough to move a lawsuit. " The information should not only consist in the manual and the Justice can be worked against to maker and against the store, to depend of each case ", it guarantees, in spite of enhancing that, in the practice, it is a very difficult situation for the consumer.