1.
Television set
–
A television set, more commonly called a television, TV, TV set, television receiver, or telly, is a device that combines a tuner, display, and loudspeakers for the purpose of viewing television. Introduced in the late 1920s in mechanical form, television became a popular consumer product after World War II in electronic form. The addition of color to broadcast television after 1953 further increased the popularity of television sets in the 1960s, the ubiquitous television set became the display device for the first recorded media in the 1970s, such as Betamax, VHS and later DVD. It was also the display device for the first generation of home computers, in the 2010s flat panel television incorporating liquid-crystal displays, especially LED-backlit LCDs, largely replaced cathode ray tubes and other displays. Modern flat panel TVs are typically capable of display and can also play content from a USB device. Mechanical televisions were sold from 1928 to 1934 in the United Kingdom, United States. The Baird Televisor is considered the first mass-produced television, selling about a thousand units, the first commercially made electronic televisions with cathode ray tubes were manufactured by Telefunken in Germany in 1934, followed by other makers in France, Britain, and America. The cheapest model with a 12-inch screen was $445, an estimated 19,000 electronic televisions were manufactured in Britain, and about 1,600 in Germany, before World War II. About 7, 000–8,000 electronic sets were made in the U. S. before the War Production Board halted manufacture in April 1942, production resuming in August 1945. While only 0. 5% of U. S. households had a television in 1946,55. 7% had one in 1954, and 90% by 1962. In Britain, there were 15,000 television households in 1947,1.4 million in 1952, by the late 1960s and early 1970s, color television had come into wide use. In Britain, BBC1, BBC2 and ITV were regularly broadcasting in colour by 1969, during the first decade of the 21st century, CRT picture tube display technology was almost entirely supplanted worldwide by flat panel displays. By the early 2010s, LCD TVs, which increasingly used LED-backlit LCDs, television sets may employ one of several available display technologies. The production of plasma and CRT displays has been almost completely discontinued, the cathode ray tube is a vacuum tube containing one or more electron guns and a fluorescent screen used to view images. It has a means to accelerate and deflect the beam onto the screen to create the images. The images may represent electrical waveforms, pictures, radar targets or others, the CRT uses an evacuated glass envelope which is large, deep, fairly heavy, and relatively fragile. As a matter of safety, the face is made of thick lead glass so as to be highly shatter-resistant and to block most X-ray emissions. In television sets and computer monitors, the front area of the tube is scanned repetitively and systematically in a fixed pattern called a raster
2.
Satellite television
–
A direct-broadcast satellite is a type of artificial satellite which usually broadcasts satellite television signals for home reception. The type of satellite television which uses direct-broadcast satellites is known as direct-broadcast satellite television or direct-to-home television and these services were to use the D-Mac and D2-Mac format and BSS frequencies with circular polarization from orbital positions allocated to each country. Before these DBS satellites, home satellite television in Europe was limited to a few channels, really intended for cable distribution, in 1977, the ITU adopted an international BSS Plan under which each country was allocated specific frequencies at specific orbital locations for domestic service. Over the years, this plan has been modified to, for example, accommodate new countries, increase coverage areas, at present, numerous countries have brought into use their BSS Plan allocations. By contrast, the term DTH can apply to similar services transmitted over a range of frequencies transmitted from satellites that are not part of any internationally planned band. The term DBS is often used interchangeably with DTH to cover both analog and digital video and audio services received by relatively small dishes, a DBS service usually refers to either a commercial service, or a group of free channels available from one orbital position targeting one country. In certain regions of the world, especially in North America, DBS is used to refer to providers of subscription satellite packages, the second commercial DBS service, Sky Television plc, was launched in 1989. Sky TV started as a four-channel free-to-air analogue service on the Astra 1A satellite, by 1991, Sky had changed to a conditional access pay model, and it launched a digital service, Sky Digital, in 1998, with analogue transmission ceasing in 2001. Since the DBS nomenclature is used in the UK or Ireland. News Corporation has a 32% stake in BSkyB, PrimeStar began transmitting an analog service to North America in 1991, and was joined by DirecTV, in 1994. At the time, DirecTVs introduction was the most successful consumer electronics debut in American history, although PrimeStar transitioned to a digital system in 1994, it was ultimately unable to compete with DirecTV, which required a smaller satellite dish and could deliver more programming. DirecTV purchased PrimeStar in 1999 and moved all of that subscribers to DirecTV equipment. In 2008, Liberty Media Corporation purchased News Corporations controlling interest in DirecTV, in 1996, EchoStars Dish Network went online in the United States and, as DirecTVs primary competitor, achieved similar success. AlphaStar also started but soon went under, astro was also started, using a direct broadcast satellite system. Dominion Video Satellite Inc. s Sky Angel launched on a platform in the United States in 1996, with its DBS service geared toward the faith. It grew from six to 36 television and radio channels of entertainment, Christian-inspirational programming. Dominion, under its corporate name Video Satellite Systems Inc. Sky Angel, although a separate and independent DBS service, used the satellites, transmission facilities
3.
Los Angeles Times
–
The Los Angeles Times, commonly referred to as the Times or LA Times, is a paid daily newspaper published in Los Angeles, California, since 1881. It was the largest metropolitan newspaper in circulation in the United States in 2008, the Times is owned by tronc. The Times was first published on December 4,1881, as the Los Angeles Daily Times under the direction of Nathan Cole Jr. and it was first printed at the Mirror printing plant, owned by Jesse Yarnell and T. J. Unable to pay the bill, Cole and Gardiner turned the paper over to the Mirror Company. Mathes had joined the firm, and it was at his insistence that the Times continued publication, in July 1882, Harrison Gray Otis moved from Santa Barbara to become the papers editor. Otis made the Times a financial success, in an era where newspapers were driven by party politics, the Times was directed at Republican readers. As was typical of newspapers of the time, the Times would sit on stories for several days, historian Kevin Starr wrote that Otis was a businessman capable of manipulating the entire apparatus of politics and public opinion for his own enrichment. Otiss editorial policy was based on civic boosterism, extolling the virtues of Los Angeles, the efforts of the Times to fight local unions led to the October 1,1910 bombing of its headquarters, killing twenty-one people. Two union leaders, James and Joseph McNamara, were charged, the American Federation of Labor hired noted trial attorney Clarence Darrow to represent the brothers, who eventually pleaded guilty. Upon Otiss death in 1917, his son-in-law, Harry Chandler, Harry Chandler was succeeded in 1944 by his son, Norman Chandler, who ran the paper during the rapid growth of post-war Los Angeles. Family members are buried at the Hollywood Forever Cemetery near Paramount Studios, the site also includes a memorial to the Times Building bombing victims. The fourth generation of family publishers, Otis Chandler, held that position from 1960 to 1980, Otis Chandler sought legitimacy and recognition for his familys paper, often forgotten in the power centers of the Northeastern United States due to its geographic and cultural distance. He sought to remake the paper in the model of the nations most respected newspapers, notably The New York Times, believing that the newsroom was the heartbeat of the business, Otis Chandler increased the size and pay of the reporting staff and expanded its national and international reporting. In 1962, the paper joined with the Washington Post to form the Los Angeles Times-Washington Post News Service to syndicate articles from both papers for news organizations. During the 1960s, the paper won four Pulitzer Prizes, more than its previous nine decades combined, eventually the coupon-clipping branches realized that they could make more money investing in something other than newspapers. Under their pressure the companies went public, or split apart, thats the pattern followed over more than a century by the Los Angeles Times under the Chandler family. The papers early history and subsequent transformation was chronicled in an unauthorized history Thinking Big and it has also been the whole or partial subject of nearly thirty dissertations in communications or social science in the past four decades. In 2000, the Tribune Company acquired the Times, placing the paper in co-ownership with then-WB -affiliated KTLA, which Tribune acquired in 1985
4.
Central processing unit
–
The computer industry has used the term central processing unit at least since the early 1960s. The form, design and implementation of CPUs have changed over the course of their history, most modern CPUs are microprocessors, meaning they are contained on a single integrated circuit chip. An IC that contains a CPU may also contain memory, peripheral interfaces, some computers employ a multi-core processor, which is a single chip containing two or more CPUs called cores, in that context, one can speak of such single chips as sockets. Array processors or vector processors have multiple processors that operate in parallel, there also exists the concept of virtual CPUs which are an abstraction of dynamical aggregated computational resources. Early computers such as the ENIAC had to be rewired to perform different tasks. Since the term CPU is generally defined as a device for software execution, the idea of a stored-program computer was already present in the design of J. Presper Eckert and John William Mauchlys ENIAC, but was initially omitted so that it could be finished sooner. On June 30,1945, before ENIAC was made, mathematician John von Neumann distributed the paper entitled First Draft of a Report on the EDVAC and it was the outline of a stored-program computer that would eventually be completed in August 1949. EDVAC was designed to perform a number of instructions of various types. Significantly, the programs written for EDVAC were to be stored in high-speed computer memory rather than specified by the wiring of the computer. This overcame a severe limitation of ENIAC, which was the considerable time, with von Neumanns design, the program that EDVAC ran could be changed simply by changing the contents of the memory. Early CPUs were custom designs used as part of a larger, however, this method of designing custom CPUs for a particular application has largely given way to the development of multi-purpose processors produced in large quantities. This standardization began in the era of discrete transistor mainframes and minicomputers and has accelerated with the popularization of the integrated circuit. The IC has allowed increasingly complex CPUs to be designed and manufactured to tolerances on the order of nanometers, both the miniaturization and standardization of CPUs have increased the presence of digital devices in modern life far beyond the limited application of dedicated computing machines. Modern microprocessors appear in electronic devices ranging from automobiles to cellphones, the so-called Harvard architecture of the Harvard Mark I, which was completed before EDVAC, also utilized a stored-program design using punched paper tape rather than electronic memory. Relays and vacuum tubes were used as switching elements, a useful computer requires thousands or tens of thousands of switching devices. The overall speed of a system is dependent on the speed of the switches, tube computers like EDVAC tended to average eight hours between failures, whereas relay computers like the Harvard Mark I failed very rarely. In the end, tube-based CPUs became dominant because the significant speed advantages afforded generally outweighed the reliability problems, most of these early synchronous CPUs ran at low clock rates compared to modern microelectronic designs. Clock signal frequencies ranging from 100 kHz to 4 MHz were very common at this time, the design complexity of CPUs increased as various technologies facilitated building smaller and more reliable electronic devices
5.
Power supply
–
A power supply is an electronic device that supplies electric energy to an electrical load. The primary function of a supply is to convert one form of electrical energy to and, as a result. Some power supplies are discrete, stand-alone devices, whereas others are built into larger devices along with their loads, examples of the latter include power supplies found in desktop computers and consumer electronics devices. Every power supply must obtain the energy it supplies to its load, as well as any energy it consumes while performing that task, all power supplies have a power input, which receives energy from the energy source, and a power output that delivers energy to the load. Some power supplies have other types of inputs and outputs as well, for such as external monitoring. Power supplies are categorized in ways, including by functional features. For example, a power supply is one that maintains constant output voltage or current despite variations in load current or input voltage. Conversely, the output of a power supply can change significantly when its input voltage or load current changes. Adjustable power supplies allow the voltage or current to be programmed by mechanical controls, or by means of a control input. An adjustable regulated power supply is one that is adjustable and regulated. Power supplies are packaged in different ways and classified accordingly, a bench power supply is a stand-alone desktop unit used in applications such as circuit test and development. Open frame power supplies have only a partial mechanical enclosure, sometimes consisting of only a mounting base, rack mount power supplies are designed to be secured into standard electronic equipment racks. An integrated power supply is one that shares a common printed circuit board with its load, power supplies can be broadly divided into linear and switching types. Linear power converters process the power directly, with all active power conversion components operating in their linear operating regions. In switching power converters, the power is converted to AC or to DC pulses before processing. A DC power supply is one that supplies a constant DC voltage to its load, depending on its design, a DC power supply may be powered from a DC source or from an AC source such as the power mains. Some DC power supplies use AC mains electricity as an energy source, such power supplies will sometimes employ a transformer to convert the input voltage to a higher or lower AC voltage. A rectifier is used to convert the output voltage to a varying DC voltage
6.
Ethernet
–
Ethernet /ˈiːθərnɛt/ is a family of computer networking technologies commonly used in local area networks, metropolitan area networks and wide area networks. It was commercially introduced in 1980 and first standardized in 1983 as IEEE802.3, over time, Ethernet has largely replaced competing wired LAN technologies such as token ring, FDDI and ARCNET. The original 10BASE5 Ethernet uses coaxial cable as a medium, while the newer Ethernet variants use twisted pair. Over the course of its history, Ethernet data transfer rates have increased from the original 2.94 megabits per second to the latest 100 gigabits per second. The Ethernet standards comprise several wiring and signaling variants of the OSI physical layer in use with Ethernet, systems communicating over Ethernet divide a stream of data into shorter pieces called frames. As per the OSI model, Ethernet provides services up to, since its commercial release, Ethernet has retained a good degree of backward compatibility. Features such as the 48-bit MAC address and Ethernet frame format have influenced other networking protocols, the primary alternative for some uses of contemporary LANs is Wi-Fi, a wireless protocol standardized as IEEE802.11. Ethernet was developed at Xerox PARC between 1973 and 1974 and it was inspired by ALOHAnet, which Robert Metcalfe had studied as part of his PhD dissertation. In 1975, Xerox filed a patent application listing Metcalfe, David Boggs, Chuck Thacker, in 1976, after the system was deployed at PARC, Metcalfe and Boggs published a seminal paper. Metcalfe left Xerox in June 1979 to form 3Com and he convinced Digital Equipment Corporation, Intel, and Xerox to work together to promote Ethernet as a standard. The so-called DIX standard, for Digital/Intel/Xerox, specified 10 Mbit/s Ethernet, with 48-bit destination and source addresses and it was published on September 30,1980 as The Ethernet, A Local Area Network. Data Link Layer and Physical Layer Specifications, version 2 was published in November,1982 and defines what has become known as Ethernet II. Formal standardization efforts proceeded at the time and resulted in the publication of IEEE802.3 on June 23,1983. Ethernet initially competed with two largely proprietary systems, Token Ring and Token Bus, in the process, 3Com became a major company. 3Com shipped its first 10 Mbit/s Ethernet 3C100 NIC in March 1981, an Ethernet adapter card for the IBM PC was released in 1982, and, by 1985, 3Com had sold 100,000. Parallel port based Ethernet adapters were produced for a time, with drivers for DOS, by the early 1990s, Ethernet became so prevalent that it was a must-have feature for modern computers, and Ethernet ports began to appear on some PCs and most workstations. This process was sped up with the introduction of 10BASE-T and its relatively small modular connector. Since then, Ethernet technology has evolved to meet new bandwidth, in addition to computers, Ethernet is now used to interconnect appliances and other personal devices
7.
Satellite dish
–
A satellite dish is a dish-shaped type of parabolic antenna designed to receive electromagnetic signals from satellites, which transmit data transmissions or broadcasts, such as satellite television. The parabolic shape of a dish reflects the signal to the focal point. Mounted on brackets at the focal point is a device called a feedhorn. This feedhorn is essentially the front-end of a waveguide that gathers the signals at or near the focal point, the LNB converts the signals from electromagnetic or radio waves to electrical signals and shifts the signals from the downlinked C-band and/or Ku-band to the L-band range. Direct broadcast satellite dishes use an LNBF, which integrates the feedhorn with the LNB, the theoretical gain of a dish increases as the frequency increases. The actual gain depends on factors including surface finish, accuracy of shape. A typical value for a consumer type 60 cm satellite dish at 11.75 GHz is 37.50 dB, with lower frequencies, C-band for example, dish designers have a wider choice of materials. The large size of dish required for lower frequencies led to the dishes being constructed from metal mesh on a metal framework, at higher frequencies, mesh type designs are rarer though some designs have used a solid dish with perforations. A common misconception is that the LNBF, the device at the front of the dish, modern dishes intended for home television use are generally 43 cm to 80 cm in diameter, and are fixed in one position, for Ku-band reception from one orbital position. Prior to the existence of direct broadcast satellite services, home users would generally have a motorised C-band dish of up to 3 m in diameter for reception of channels from different satellites. Overly small dishes can still cause problems, however, including rain fade, in Europe, the frequencies used by DBS services are 10. 7–12.75 GHz on two polarisations H and V. This range is divided into a low band with 10. 7–11.7 GHz, and this results in two frequency bands, each with a bandwidth of about 1 GHz, each with two possible polarizations. In the LNB they become down converted to 950–2150 MHz, which is the range allocated for the satellite service on the coaxial cable between LNBF and receiver. Lower frequencies are allocated to cable and terrestrial TV, FM radio, in a single receiver residential installation there is a single coaxial cable running from the receiver set-top box in the building to the LNB on the dish. The DC electric power for the LNB is provided through the coaxial cable conductors that carry the signal to the receiver. In addition, control signals are transmitted from the receiver to the LNB through the cable. The receiver uses different power supply voltages to select antenna polarization, a satellite finder may aid in aiming. A dish that is mounted on a pole and driven by a motor or a servo can be controlled and rotated to face any satellite position in the sky
8.
Coaxial cable
–
Coaxial cable, or coax, is a type of cable that has an inner conductor surrounded by a tubular insulating layer, surrounded by a tubular conducting shield. Many coaxial cables also have an outer sheath or jacket. The term coaxial comes from the conductor and the outer shield sharing a geometric axis. Coaxial cable was invented by English engineer and mathematician Oliver Heaviside, Coaxial cable is used as a transmission line for radio frequency signals. Its applications include feedlines connecting radio transmitters and receivers with their antennas, computer network connections, digital audio and this allows coaxial cable runs to be installed next to metal objects such as gutters without the power losses that occur in other types of transmission lines. Coaxial cable also provides protection of the signal from external electromagnetic interference, the cable is protected by an outer insulating jacket. Normally, the shield is kept at ground potential and a signal carrying voltage is applied to the center conductor, the advantage of coaxial design is that electric and magnetic fields are restricted to the dielectric with little leakage outside the shield. Conversely, electric and magnetic fields outside the cable are largely kept from interfering with signals inside the cable, larger diameter cables and cables with multiple shields have less leakage. Common applications of coaxial cable include video and CATV distribution, RF and microwave transmission, the characteristic impedance of the cable is determined by the dielectric constant of the inner insulator and the radii of the inner and outer conductors. A controlled cable characteristic impedance is important because the source and load impedance should be matched to ensure maximum power transfer, other important properties of coaxial cable include attenuation as a function of frequency, voltage handling capability, and shield quality. Coaxial cable design choices affect physical size, frequency performance, attenuation, power handling capabilities, flexibility, strength, the inner conductor might be solid or stranded, stranded is more flexible. To get better performance, the inner conductor may be silver-plated. Copper-plated steel wire is used as an inner conductor for cable used in the cable TV industry. The insulator surrounding the conductor may be solid plastic, a foam plastic. The properties of control some electrical properties of the cable. A common choice is a solid polyethylene insulator, used in lower-loss cables, solid Teflon is also used as an insulator. Some coaxial lines use air and have spacers to keep the conductor from touching the shield. Many conventional coaxial cables use braided copper wire forming the shield and this allows the cable to be flexible, but it also means there are gaps in the shield layer, and the inner dimension of the shield varies slightly because the braid cannot be flat
9.
Telephone
–
A telephone, or phone, is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be heard directly. In 1876, Scottish emigrant Alexander Graham Bell was the first to be granted a United States patent for a device that produced clearly intelligible replication of the human voice and this instrument was further developed by many others. The telephone was the first device in history that people to talk directly with each other across large distances. Telephones rapidly became indispensable to businesses, government, and households, the essential elements of a telephone are a microphone to speak into and an earphone which reproduces the voice in a distant location. Until approximately the 1970s most telephones used a dial, which was superseded by the modern DTMF push-button dial. The receiver and transmitter are usually built into a handset which is held up to the ear, the dial may be located either on the handset, or on a base unit to which the handset is connected. The transmitter converts the sound waves to electrical signals which are sent through the network to the receiving phone. The receiving telephone converts the signals into audible sound in the receiver, telephones permit duplex communication, meaning they allow the people on both ends to talk simultaneously. The first telephones were connected to each other from one customers office or residence to another customers location. Being impractical beyond just a few customers, these systems were replaced by manually operated centrally located switchboards. For greater mobility, various systems were developed for transmission between mobile stations on ships and automobiles in the middle 20th century. Hand-held mobile phone]s was introduced for personal service starting in 1973, by the late 1970s several mobile telephone networks operated around the world. In 1983, the Advanced Mobile Phone System was launched, offering a standardized technology providing portability for users far beyond the residence or office. These analog cellular system evolved into digital networks with better security, greater capacity, better regional coverage, the public switched telephone network, with its hierarchical system of many switching centers, interconnects telephones around the world for communication with each other. With the standardized international numbering system, E.164, each line has an identifying telephone number. Although originally designed for voice communications, convergence has enabled most modern cell phones to have many additional capabilities. Since 1999, the trend for mobile phones is smartphones that integrate all mobile communication, a traditional landline telephone system, also known as plain old telephone service, commonly carries both control and audio signals on the same twisted pair of insulated wires, the telephone line. The control and signaling equipment consists of three components, the ringer, the hookswitch, and a dial, the ringer, or beeper, light or other device, alerts the user to incoming calls
10.
Video
–
Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video systems vary greatly in the resolution of the display and refresh rate, video can be carried on a variety of media, including radio broadcast, tapes, DVDs, computer files etc. Video was originally exclusively a live technology, charles Ginsburg led an Ampex research team developing one of the first practical video tape recorder. In 1951 the first video tape recorder captured live images from television cameras by converting the electrical impulses. Video recorders were sold for $50,000 in 1956, however, prices gradually dropped over the years, in 1971, Sony began selling videocassette recorder decks and tapes into the consumer market. The use of techniques in video created digital video, which allowed higher quality and, eventually. After the invention of the DVD in 1997 and Blu-ray Disc in 2006, sales of videotape, the advent of digital broadcasting and the subsequent digital television transition is in the process of relegating analog video to the status of a legacy technology in most parts of the world. PAL standards and SECAM specify 25 frame/s, while NTSC standards specify 29.97 frames, film is shot at the slower frame rate of 24 frames per second, which slightly complicates the process of transferring a cinematic motion picture to video. The minimum frame rate to achieve a comfortable illusion of an image is about sixteen frames per second. Video can be interlaced or progressive, analog display devices reproduce each frame in the same way, effectively doubling the frame rate as far as perceptible overall flicker is concerned. NTSC, PAL and SECAM are interlaced formats, abbreviated video resolution specifications often include an i to indicate interlacing. For example, PAL video format is specified as 576i50, where 576 indicates the total number of horizontal scan lines, i indicates interlacing. In progressive scan systems, each refresh period updates all scan lines in each frame in sequence, when displaying a natively progressive broadcast or recorded signal, the result is optimum spatial resolution of both the stationary and moving parts of the image. Deinterlacing cannot, however, produce video quality that is equivalent to true progressive scan source material, aspect ratio describes the dimensions of video screens and video picture elements. All popular video formats are rectilinear, and so can be described by a ratio between width and height, the screen aspect ratio of a traditional television screen is 4,3, or about 1.33,1. High definition televisions use a ratio of 16,9. The aspect ratio of a full 35 mm film frame with soundtrack is 1.375,1. Therefore, a 720 by 480 pixel NTSC DV image displayes with the 4,3 aspect ratio if the pixels are thin, the popularity of viewing video on mobile phones has led to the growth of vertical video
.jpg)
