1.
International Electrotechnical Commission
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The IEC also manages three global conformity assessment systems that certify whether equipment, system or components conform to its International Standards. The first International Electrical Congress took place in 1881 at the International Exposition of Electricity, at that time the International System of Electrical and Magnetic Units was agreed to. The IEC was instrumental in developing and distributing standards for units of measurement, particularly Gauss, Hertz and it also first proposed a system of standards, the Giorgi System, which ultimately became the SI, or Système International d’unités. In 1938, it published a multilingual international vocabulary to unify terminology relating to electrical, electronic and this effort continues, and the International Electrotechnical Vocabulary remains an important work in the electrical and electronic industries. The CISPR – in English, the International Special Committee on Radio Interference – is one of the groups founded by the IEC, originally located in London, the commission moved to its current headquarters in Geneva in 1948. It has regional centres in Asia-Pacific, Latin America and North America, today, the IEC is the worlds leading international organization in its field, and its standards are adopted as national standards by its members. The work is done by some 10,000 electrical and electronics experts from industry, government, academia, test labs, IEC standards have numbers in the range 60000–79999 and their titles take a form such as IEC60417, Graphical symbols for use on equipment. Following the Dresden Agreement with CENELEC the numbers of older IEC standards were converted in 1997 by adding 60000, for example IEC27 became IEC60027. Standards of the 60000 series are also preceded by EN to indicate that the IEC standard is also adopted by CENELEC as a European standard. The IEC cooperates closely with the International Organization for Standardization and the International Telecommunication Union, Standards developed jointly with ISO such as ISO/IEC26300, ISO/IEC27001, and CASCO ISO/IEC17000 series, carry the acronym of both organizations. The use of the ISO/IEC prefix covers publications from ISO/IEC Joint Technical Committee 1 - Information Technology, as well as conformity assessment standards developed by ISO CASCO, other standards developed in cooperation between IEC and ISO are assigned numbers in the 80000 series, such as IEC 82045-1. IEC standards are also being adopted by other certifying bodies such as BSI, CSA, UL & ANSI/INCITS, SABS, SAI, SPC/GB, IEC standards adopted by other certifying bodies may have some noted differences from the original IEC standard. The IEC is made up of members, called national committees, national committees are constituted in different ways. Some NCs are public sector only, some are a combination of public and private sector, about 90% of those who prepare IEC standards work in industry
2.
Serial communication bus
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In telecommunication and data transmission, serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where bits are sent as a whole. Serial communication is used for all communication and most computer networks. The migration from PCI to PCI Express is an example, many serial communication systems were originally designed to transfer data over relatively large distances through some sort of data cable. Practically all long-distance communication transmits data one bit at a time, rather than in parallel, the cables that carry this data and the computer ports they plug into are usually referred to with a more specific name, to reduce confusion. Keyboard and mouse cables and ports are almost invariably serial—such as PS/2 port and Apple Desktop Bus, many communication systems were generally originally designed to connect two integrated circuits on the same printed circuit board, connected by signal traces on that board. Integrated circuits are more expensive when they have more pins, to reduce the number of pins in a package, many ICs use a serial bus to transfer data when speed is not important. Some examples of such low-cost serial buses include SPI, I²C, dc-bus, UNI/O, the communication links across which computers—or parts of computers—talk to one another may be either serial or parallel. A parallel link transmits several streams of data simultaneously along multiple channels, whereas, several factors allow serial to be clocked at a higher rate, Clock skew between different channels is not an issue. A serial connection requires fewer interconnecting cables and hence occupies less space, the extra space allows for better isolation of the channel from its surroundings. Crosstalk is less of an issue, because there are fewer conductors in proximity, in many cases, serial is cheaper to implement than parallel. Many ICs have serial interfaces, as opposed to parallel ones, so that they have fewer pins and are therefore less expensive
3.
Home automation
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Home automation or smart home is building automation for the home. It involves the control and automation of lighting, heating, ventilation, air conditioning, wi-Fi is often used for remote monitoring and control. Home devices, when remotely monitored and controlled via the Internet, are an important constituent of the Internet of Things, while there are many competing vendors, there are very few world-wide accepted industry standards and the smart home space is heavily fragmented. Popular communications protocol for products include X10, Ethernet, RS-485, 6LoWPAN, Bluetooth LE, ZigBee and Z-Wave, manufacturers often prevent independent implementations by withholding documentation and by litigation. The home automation market was worth US$5.77 billion in 2015, early home automation began with labor-saving machines. In 1975, the first general purpose home automation network technology and it is a communication protocol for electronic devices. It primarily uses electric power transmission wiring for signalling and control, where the signals involve brief radio frequency bursts of digital data, by 1978, X10 products included a 16 channel command console, a lamp module, and an appliance module. Soon after came the wall switch module and the first X10 timer, by 2012, in the United States, according to ABI Research,1.5 million home automation systems were installed. The word domotics is a contraction of the Latin word for a home, heating, ventilation and air conditioning, it is possible to have remote control of all home energy monitors over the internet incorporating a simple and friendly user interface. Technology is still in its infancy, and consumers could invest in a system that becomes abandonware. In 2014, Google bought the company selling the Revolv Hub home automation system, integrated it with Nest and in 2016 shut down the servers Revolv Hub depended on, rendering the hardware useless. Microsoft Research found in 2011, that home automation could involve high cost of ownership, inflexibility of interconnected devices, however, there are now open source software systems which can be used with proprietary hardware. There are a variety of technology platforms, or protocols. Each one is, essentially, its own language, each language speaks to the various connected devices and instructs them to perform a function. The automation protocol transport has involved direct wire connectivity, powerline and wireless hybrid, most of the protocols below are not open. Customers may be hesitant to bet their IoT future on proprietary software or hardware devices that use proprietary protocols that may fade or become difficult to customize and interconnect. The nature of home automation devices can also be a problem for security, since patches to bugs found in the operating system often do not reach users of older. One set of researchers say that the failure of vendors to support devices with patches and updates leaves more than 87% of active devices vulnerable
4.
Philips
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Koninklijke Philips N. V. is a Dutch technology company headquartered in Amsterdam with primary divisions focused in the areas of electronics, healthcare and lighting. It was founded in Eindhoven in 1891, by Gerard Philips and it is one of the largest electronics companies in the world and employs around 105,000 people across more than 60 countries. Philips is organized into three divisions, Philips Consumer Lifestyle, Philips Healthcare and Philips Lighting. As of 2012, Philips was the largest manufacturer of lighting in the world measured by applicable revenues, Philips said it would seek damages for breach of contract in the US$200-million sale. In April 2016, the International Court of Arbitration ruled in favour of Philips, Philips has a primary listing on the Euronext Amsterdam stock exchange and is a component of the Euro Stoxx 50 stock market index. It has a listing on the New York Stock Exchange. The Philips Company was founded in 1891, by Gerard Philips and this first factory has been adapted and is used as a museum. In 1895, after a difficult first few years and near bankruptcy, though he had earned a degree in engineering, Anton started work as a sales representative, soon, however, he began to contribute many important business ideas. After Gerard and Anton Philips changed their business by founding the Philips corporation. In the 1920s, the company started to other products. In 1939, they introduced their electric razor, the Philishave, the Chapel is a radio with built-in loudspeaker, which was designed during the early 1930s. On 11 March 1927, Philips went on the air with shortwave radio station PCJJ which was joined in 1929 by sister station PHOHI, PHOHI broadcast in Dutch to the Dutch East Indies while PCJJ broadcast in English, Spanish and German to the rest of the world. The international program on Sundays commenced in 1928, with host Eddie Startz hosting the Happy Station show, broadcasts from the Netherlands were interrupted by the German invasion in May 1940. The Germans commandeered the transmitters in Huizen to use for pro-Nazi broadcasts, some originating from Germany, Philips Radio was absorbed shortly after liberation when its two shortwave stations were nationalised in 1947 and renamed Radio Netherlands Worldwide, the Dutch International Service. Some PCJ programs, such as Happy Station, continued on the new station, by the late 1940s, the Type 10 was ready to be handed over to Philips subsidiary Johan de Witt in Dordrecht to be produced and incorporated into a generator set as originally planned. The result, rated at 180/200 W electrical output from a bore, approximately 150 of these sets were eventually produced. However, they filed a number of patents and amassed a wealth of information. The first Philips shaver was introduced in the 1930s, and was simply called “The Philishave”, in the USA, it was called the “Norelco”, which remains a part of their product line today
5.
SCART
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SCART is a French-originated standard and associated 21-pin connector for connecting audio-visual equipment. It is also known as Péritel, 21-pin EuroSCART, Euroconector, in America, another name is EIA Multiport. In Europe, SCART used to be the most common method of connecting AV equipment, hDMI-CEC is derived from SCARTs AV. link. However, SCART Connection can also support HD signals like 480p, 720p, 1080i, 1080p, if the SCART connection of a device is designed to support YPbPr connection, the same for multichannel audio, but even this configuration remains rare, as it is not standardized. The official standard for SCART is CENELEC document number EN 50049-1, SCART is sometimes referred to as the IEC 933-1 standard. Note that there is also a Japanese version of the SCART connector and this version of SCART uses similar signals and the same connector, but it has a different pinout. It became compulsory on new TVs sold in France from January 1980, before SCART was introduced, TVs did not offer a standardised way of inputting signals other than RF antenna connectors, and these differed between countries. Assuming other connectors even existed, devices made by various companies could have different, for example, a domestic VCR could output a composite video signal through a German-originated DIN-style connector, an American-originated RCA connector, an SO239 connector or a BNC connector. The SCART system was intended to simplify connecting AV equipment, to achieve this it gathered all of the analogue signal connections into a single cable with a unique connector that made incorrect connections nearly impossible. The signals carried by SCART include both composite and RGB video, stereo audio input/output and digital signalling, the standard was extended at the end of the 1980s to support the new S-Video signals. A TV can be awakened from standby mode, and it can switch to appropriate AV channel. SCART is bi-directional regarding standard composite video and analogue audio, a TV will typically send the antenna audio and video signals to the SCART sockets all the time and watch for returned signals, to display and reproduce them. This allows transparent set-top boxes, without any tuner, which just hook and this feature is used for analogue pay TV like Canal Plus and was used for decoding teletext. A VCR will often have two SCART sockets, to connect it to the TV, and for input from a set-top box or other device. When idle or powered off, VCRs will usually forward the signals from the TV to the set-top decoder and send the processed result back to the TV. When a scrambled show is recorded, the VCR will drive the box from its own tuner. Alternatively, the VCR could use the signals from the TV, the down socket can also be used to connect other devices, such as DVD players or game consoles. As long as all devices have at least one up and down socket, while audio and video signals can travel both up to the TV and down to devices farther away from the TV, this is not true for RGB signals, which can only travel towards the TV
6.
E-series of preferred numbers
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The E-series is a system of preferred numbers derived for use in electronics. It consists of the E3, E6, E12, E24, E48, E96 and E192 series. It works similarly to the Renard series, except that it subdivides the interval from 1 to 10 into 3,6,12 and 24, and later also 48,96 or 192 steps. These subdivisions ensure that when some arbitrary value is replaced with the nearest preferred number, use of the IEC or EIA E series is mostly restricted to resistors, capacitors, inductors and Zener diodes. Commonly produced dimensions for other types of components are either chosen from the Renard series instead or are defined in relevant product standards. The IEC60063 numbers are as follows.7 to 4.7 and 8.2 do not follow the rules exactly. The E192 series is used for 0. 25% and 0. 1% tolerance resistors. 1% resistors are available in both the E24 values and the E96 values, preferred numbers Renard series 1-2-5 series Geometric progression
7.
IEC 60269
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In electrical engineering, IEC60269 is a set of technical standards for low-voltage power fuses. The standard is in four volumes, which describe general requirements, fuses for industrial and commercial applications, fuses for residential applications, the IEC standard unifies several national standards, thereby improving the interchangeability of fuses in international trade. All fuses of different technologies tested to meet IEC standards will have similar time-current characteristics, north American standards call the replaceable element only the fuse. IEC60269 unifies the electrical characteristics of fuses that are interchangeable with fuses built to earlier British, German. The standard identifies application categories which classify the time-current characteristic of type of fuse. The application category is a two-digit code, the first letter is a if the fuse is for short-circuit protection only, an associated device must provide overload protection. The first letter is g if the fuse is intended to operate even with currents as low as those that cause it to blow in one hour and these are considered general-purpose fuses for protection of wires. Fuses of the same application category can be substituted for each other provided the voltage rating of the circuit does not exceed the fuse rating and they are available in five different body sizes, with ratings from 2 A up to 200 A. The designation of a size consists of the letter D and a Roman numeral, higher-voltage types rated up to 750 V have increased clearance distances and are longer than lower-voltage-rated fuses. D0-type fuses are similar but have a smaller, cylindrical body and they are available in three different sizes with ratings from 2 A up to 100 A. In some jurisdictions, replacement of the cartridge by unskilled personnel is allowed only for fuses up to a certain maximum rating. If the fuse cartridge is inserted into the socket without the cap, fuseholders may be secured by screws to a panel, attached to bus bars, or mounted on DIN rails. For the Neozed fuses, there are also fuse bases with integrated disconnecting switches, changing fuses with the circuit off increases the safety of the user. With new versions of these load disconnecting switches, the cartridges are no longer screwed. Traditional diazed fuse holders are made as a metal envelope covered with non-conducting porcelain cover. Under mechanical stress it is possible for the cover to crack partially or fully and it may happen if a fuse holder was accidentally dropped or someone was using too much force to screw it in. Uncovered metal envelopes present a risk of shock and should be replaced immediately under extreme precautions by trained personnel. The smaller end cap has a diameter that varies with the fuse rating, the fixed part of the fuse holder contains a gauge ring, which will accept end caps up to a certain diameter
8.
19-inch rack
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A 19-inch rack is a standardized frame or enclosure for mounting multiple electronic equipment modules. Each module has a front panel that is 19 inches wide, the 19-inch dimension includes the edges, or ears, that protrude on each side which allow the module to be fastened to the rack frame with screws. Common uses include server, audio, and scientific lab equipment, the height of the electronic modules is also standardized as multiples of 1.752 inches or one rack unit or U. The industry standard rack cabinet is 42U tall, the term relay rack appeared first in the world of telephony. By 1911, the term was also being used in railroad signaling, there is little evidence that the dimensions of these early racks were standardized. The 19-inch rack format with rack-units of 1.75 inches was established as a standard by AT&T around 1922 in order to reduce the space required for repeater, the earliest repeaters from 1914 were installed in ad-hoc fashion on shelves, in wooden boxes and cabinets. Once serial production started, they were built into bespoke racks, the height of the different panels will vary, but in all cases to be a whole multiple of 1¾ inches. The 19-inch rack format has remained constant while the technology that is mounted within it has changed considerably, nineteen-inch racks in two-post or four-post form hold most equipment in modern data centers, ISP facilities, and professionally designed corporate server rooms. They allow for dense hardware configurations without occupying excessive floorspace or requiring shelving, nineteen-inch racks are also often used to house professional audio and video equipment, including amplifiers, effects units, interfaces, headphone amplifiers, and even small scale audio mixers. A third common use for rack-mounted equipment is industrial power, control, typically, a piece of equipment being installed has a front panel height 1⁄32 inch less than the allotted number of Us. Thus, a 1U rackmount computer is not 1.75 inches tall but is 1.719 inches tall, 2U would be 3.469 inches instead of 3.5 inches. This gap allows a bit of room above and below a piece of equipment so it may be removed without binding on the adjacent equipment. State-of-the-art rackmount cases are now constructed of thermo stamped composite, carbon fiber. Originally, the holes were tapped with a particular screw thread. Tapping large numbers of holes that may never be used is expensive, nonetheless tapped-hole racks are still in use, examples include telephone exchanges, network cabling panels, broadcast studios and some government and military applications. The tapped-hole rack was first replaced by clearance-hole racks, the holes are large enough to permit a bolt to be freely inserted through without binding, and bolts are fastened in place using cage nuts. In the event of a nut being stripped out or a bolt breaking, production of clearance-hole racks is less expensive because tapping the holes is eliminated and replaced with fewer, less expensive, cage nuts. The next innovation in design has been the square-hole rack
9.
IEC 60309
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IEC60309 is an international standard from the International Electrotechnical Commission for plugs, socket-outlets and couplers for industrial purposes. The highest voltage allowed by the standard is 690 V DC or AC, the highest current,125 A, the temperature range is −25 °C to 40 °C. There is a range of plugs and sockets of different sizes with differing numbers of pins, depending on the current supplied, the fittings are popular in open-air conditions, as they include IP44 weather-proofing. The blue fittings are used for providing weather-proofed exterior sockets for outdoor apparatus. In camping situations, the large 32 A blue fittings provide power to static caravans, whilst the smaller blue 16 A version powers touring caravans, the red three-phase versions are used for three-phase portable equipment. IEC 60309-1 specifies general functional and safety requirements for any form of industrial high-current power connector, IEC 60309-2 specifies a range of mains power connectors with circular housings, and different numbers and arrangements of pins for different applications. IEC 60309-3 dealt with connectors for use in explosive gas environments, the standardization was originally done by the CEE, which becale IECEE in 1985 and is now part of the IEC. The industrial sockets were standardized in the 1960s in the CEE17 series that was adopted in the UK as BS4343, IEC 60309-4 concerns switched socket-outlets and connector interlocks. In the United Kingdom, this standard was first adopted as BS4343,1968 and has since replaced by its European equivalent BS EN 60309-4. In the UK these plugs are often referred to as caravan, Commando, CEE industrial, IEC60309 connectors come in IP44 and IP67 variants. In both cases, the rating applies when detached or mated, but not during the mating process, the more common IP44 variant features a spring-loaded hinged cap over the socket. When a plug is inserted, the cap hooks over a lug on the plug, fixed connectors are usually installed angled downward to prevent water entering. The IP67 variant includes a gasket and twist-lock ring which seals the two together, the two can be intermated, at the cost of the locking mechanisms, they are only held by friction. The connectors come in four current ratings 16,32,63 or 125 A per pin, All consist of cylindrical connector pins arranged in a circle, with the earth pin 2 mm larger than the others. This is surrounded by a shroud on the male connector. The standard defines connectors with 3,4 and 5 pins, but a variant with 7 pins is commercially available. The key protrudes an additional 3 or 4 mm beyond the shroud diameter, connectors rated at 63 A and 125 A may optionally be equipped with a 6 mm pilot contact. This smaller pin in the centre of the connector is shorter than the others, designed to make all the other pins when connecting a plug and socket
10.
IEC 60320
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Different types of connector are specified for different combinations of current, temperature and earthing requirements. Unlike IEC60309 connectors, they are not coded for voltage, the first edition of IEC320 was published in 1970. Interconnection couplers allow a supply from a piece of equipment or an appliance to be made available to other equipment or appliances. Couplers described under these standards have standardized current and temperature ratings, each type of coupler is identified by a standard sheet number. Many types of coupler also have common names, the most common ones are IEC connector for the common C13 and C14, the figure-8 connector for C7 and C8, and cloverleaf connector or Mickey Mouse connector for the C5/C6. Kettle plug is a term used for the high-temperature C16 appliance inlet. Kettle plug is sometimes used to refer to regular temperature-rated C13 and C14 connectors. Detachable appliance couplers are used in equipment, measuring instruments, IT environments. Each appliances power system must be adapted to the different plugs used in different regions, instead, a country-specific power supply cord can be included in the product packaging, so that model variations are minimized and factory testing is simplified. A cord which is fitted with non-rewireable connectors at both ends is termed a cord set, appliance manufacturing may be simplified by mounting an appliance coupler directly on the printed circuit board. Assembly and handling of an appliance is easier if the cord can be removed without much effort. Appliances can be used in another country easily, with a change of the power supply cord. The power supply cord can be replaced if damaged, because it is a standardized part that can be unplugged and re-inserted. Safety hazards, maintenance expenditure and repairs are minimized, IEC60320 is divided into several parts, IEC 60320-1, General Requirements specifies two-pole and two-pole with earth couplers intended for the connection of a supply cord to electrical appliances. As from IEC 60320-1,2015 this part also applies to interconnection couplers which enable the connection and disconnection of an appliance to a cord leading to another appliance. This part of the no longer includes standard sheets which have been moved to a new part first published in 2014. IEC 60320-2-1, Sewing machine couplers specifies couplers which are not interchangeable with other couplers from IEC60320 and they are rated no higher than 2.5 amperes and 250 volts. IEC 60320-2-2 Interconnection couplers for household and similar equipment and this section was withdrawn in January 2016
11.
IEEE 754
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The IEEE Standard for Floating-Point Arithmetic is a technical standard for floating-point computation established in 1985 by the Institute of Electrical and Electronics Engineers. The standard addressed many problems found in the floating point implementations that made them difficult to use reliably and portably. Many hardware floating point units now use the IEEE754 standard, the international standard ISO/IEC/IEEE60559,2011 has been approved for adoption through JTC1/SC25 under the ISO/IEEE PSDO Agreement and published. The binary formats in the standard are included in the new standard along with three new basic formats. To conform to the current standard, an implementation must implement at least one of the formats as both an arithmetic format and an interchange format. As of September 2015, the standard is being revised to incorporate clarifications, an IEEE754 format is a set of representations of numerical values and symbols. A format may also include how the set is encoded, a format comprises, Finite numbers, which may be either base 2 or base 10. Each finite number is described by three integers, s = a sign, c = a significand, q = an exponent, the numerical value of a finite number is s × c × bq where b is the base, also called radix. For example, if the base is 10, the sign is 1, the significand is 12345, two kinds of NaN, a quiet NaN and a signaling NaN. A NaN may carry a payload that is intended for diagnostic information indicating the source of the NaN, the sign of a NaN has no meaning, but it may be predictable in some circumstances. Hence the smallest non-zero positive number that can be represented is 1×10−101 and the largest is 9999999×1090, the numbers −b1−emax and b1−emax are the smallest normal numbers, non-zero numbers between these smallest numbers are called subnormal numbers. Zero values are finite values with significand 0 and these are signed zeros, the sign bit specifies if a zero is +0 or −0. Some numbers may have several representations in the model that has just been described, for instance, if b=10 and p=7, −12.345 can be represented by −12345×10−3, −123450×10−4, and −1234500×10−5. However, for most operations, such as operations, the result does not depend on the representation of the inputs. For the decimal formats, any representation is valid, and the set of representations is called a cohort. When a result can have several representations, the standard specifies which member of the cohort is chosen, for the binary formats, the representation is made unique by choosing the smallest representable exponent. For numbers with an exponent in the range, the leading bit of the significand will always be 1. Consequently, the leading 1 bit can be implied rather than explicitly present in the memory encoding and this rule is called leading bit convention, implicit bit convention, or hidden bit convention
12.
IEC 60906-1
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IEC 60906-1 is an international standard for 230 V AC domestic power plugs and sockets. It was conceived as a common mains plug and socket standard for use in territories with 230 V mains, the standard was originally published by the International Electrotechnical Commission in 1986, the current edition is ed2.0 published in 2009. Although it looks similar to the Swiss SEV1011 plug, its dimensions are different, as of July 2014, only South Africa has introduced a standard based closely on IEC-60906-1. Brazil used it as the basis for its NBR14136 standard and this article is only about part one of IEC60906. Part two, IEC 60906-2, defines a standard plug for 100–130 V mains compatible with the NEMA 5-15 plug and receptacle used today in North America. Part three, IEC 60906-3, defines a family of low voltage connectors. IEC 60906-1 plugs and socket-outlets are rated 16 A,250 V AC and are intended for use on systems having nominal voltages between 200 V and 250 V AC. IEC 60906-1 defines both 3-pin connectors for Class I appliances and 2-pin versions for Class II appliances, the IEC 60906-1 plugs are smaller than any other European plug with 16 A rating. The sockets are small enough that two can be installed in the space taken by a single Schuko or BS1363 socket, the plugs are slightly larger than the Europlug and provide much more reliable contact. The socket has either a 10 mm deep recess or a 12 mm high rim and it ensures that the protective-earth pin establishes contact before the line and neutral pins. Sockets are required to have shutters for the line and neutral apertures, however, the IEC 60906-1 standard explicitly discourages the use of multi-standard sockets, claiming that such sockets are likely to create safety problems when used with plugs from other countries. IEC 60906-1 plugs are similar in size and shape to the Europlug and they are nominally 35.5 mm wide. The 3-pin Class I plug is 17 mm high, whereas the 2-pin Class II plug is 14 mm high, the parallel side faces are 26 mm apart, and the two pairs of side faces are orthogonal to each other. The line and neutral pin are on centres spaced at 19 mm, the pins are 19 mm in length with a diameter of 4.5 mm. In common with the Europlug there is a sleeve around the base of the line. The 3-pin version has a round protective-earth pin of the length and diameter as the line and neutral pins. The protective-earth pins center is offset 3 mm from the point between the line and neutral pin. South Africa is the country to have incorporated IEC 60906-1 plugs
13.
Compact Disc Digital Audio
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Compact Disc Digital Audio is the standard format for audio compact discs. The standard is defined in the Red Book, one of a series of Rainbow Books that contain the specifications for all Compact Disc formats. These parameters are common to all discs and used by all logical formats. The standard also specifies the form of audio encoding, 2-channel signed 16-bit Linear PCM sampled at 44,100 Hz. Although rarely used, the specification allows for discs to be mastered with a form of emphasis, the second edition of IEC60908 was published in 1999 and it cancels and replaces the first edition, amendment 1 and the corrigendum to amendment 1. The IEC60908 however does not contain all the information for extensions that is available in the Red Book, such as the details for CD-Text, CD+G, the standard is not freely available and must be licensed. It is available from Philips and the IEC, as of 2013, Philips outsources licensing of the standard to Adminius, which charges US$100 for the Red Book, plus US$50 each for the Subcode Channels R-W and CD Text Mode annexes. The audio contained in a CD-DA consists of two-channel signed 16-bit Linear PCM sampled at 44,100 Hz, the sampling rate is adapted from that attained when recording digital audio on a PAL videotape with a PCM adaptor, an earlier way of storing digital audio. An audio CD can represent frequencies up to 22.05 kHz, the selection of the sample rate was based primarily on the need to reproduce the audible frequency range of 20–20,000 Hz. The Nyquist–Shannon sampling theorem states that a rate of more than twice the maximum frequency of the signal to be recorded is needed. The exact sampling rate of 44, the device that converts an analog audio signal into PCM audio, which in turn is changed into an analog video signal is called a PCM adaptor. This technology could store six samples in a horizontal line. 60 field/s black and white video was required, and in NTSC countries that video signal has 245 usable lines per field, similarly, PAL has 294 lines and 50 fields, which gives 44,100 samples/s/stereo channel. This system could store 14-bit samples with some correction, or 16-bit samples with almost no error correction. There was a debate over the use of 14-bit or 16-bit quantization. When the Sony/Philips task force designed the Compact Disc, Philips had already developed a 14-bit D/A converter, in the end,16 bits and 44.1 kilosamples per second prevailed. Philips found a way to produce 16-bit quality using its 14-bit DAC by using four times oversampling, some CDs are mastered with pre-emphasis, an artificial boost of high audio frequencies. The pre-emphasis improves the apparent signal-to-noise ratio by making use of the channels dynamic range
14.
AES3
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AES3 is a standard for the exchange of digital audio signals between professional audio devices. AES3 was jointly developed by the Audio Engineering Society and the European Broadcasting Union, an AES3 signal can carry two channels of PCM audio over several transmission media including balanced lines, unbalanced lines, and optical fiber. It was published in 1985 and has been revised in 1992 and 2003, AES3 has been incorporated into the International Electrotechnical Commissions standard IEC60958, and is available in a consumer-grade variant known as S/PDIF. Early on, the standard was known as AES/EBU. Both AES and EBU versions of the standard exist and these variants are commonly known as S/PDIF. The standard has been revised in 1992 and 2003 and is published in AES, worldwide, it is the most commonly used method for digitally interconnecting audio equipment. The AES3 standard parallels part 4 of the international standard IEC60958, of the physical interconnection types defined by IEC60958, three are in common use. Type I connections use balanced, 3-conductor, 110-ohm twisted pair cabling with XLR connectors, Type I connections are most often used in professional installations and are considered the AES3 standard connector. The hardware interface is implemented using RS-422 line drivers and receivers. Type II connections use unbalanced, 2-conductor, 75-ohm coaxial cable with RCA connectors, Type II connections are used in most often in consumer audio installations and are often called coaxial S/PDIF connections. Type III Optical connections use optical fiber—usually plastic, but occasionally glass—with F05 connectors, like Type II, Type III Optical connections are also used in consumer audio installations and are often called optical S/PDIF connections. The AES-3id standard defines a 75-ohm BNC electrical variant of AES3 and this uses the same cabling, patching and infrastructure as analogue or digital video, and is thus common in the broadcast industry. AES3 digital audio format can also be carried over an Asynchronous Transfer Mode network, the standard for packing AES3 frames into ATM cells is AES47. For information on the synchronization of digital audio structures, see the AES11 standard, the ability to insert unique identifiers into an AES3 bit stream is covered by the AES52 standard. The precursor of the IEC60958 Type II specification was the Sony/Philips Digital Interface, the low-level protocol for data transmission in AES3 and S/PDIF is largely identical, and the following discussion applies for S/PDIF, except as noted. AES3 was designed primarily to support stereo PCM encoded audio in either DAT format at 48 kHz or CD format at 44.1 kHz. No attempt was made to use a carrier able to support both rates, instead, AES3 allows the data to be run at any rate, and encoding the clock, the basic unit of transmission is the frame. Frames contain 64 time slots and are produced once per sample time, at the highest level, each 192 consecutive frames are grouped into an audio block
15.
S/PDIF
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S/PDIF is a type of digital audio interconnect used in consumer audio equipment to output audio over reasonably short distances. The signal is transmitted over either a cable with RCA connectors or a fibre optic cable with TOSLINK connectors. S/PDIF interconnects components in home theatres and other digital high-fidelity systems, S/PDIF is based on the AES3 interconnect standard. S/PDIF is a link layer protocol as well a set of physical layer specifications for carrying digital audio signals between devices and components over either optical or electrical cable. The name stands for Sony/Philips Digital Interconnect Format but is known as Sony/Philips Digital Interface. Sony and Philips were the designers of S/PDIF. S/PDIF is standardized in IEC60958 as IEC60958 type II, a common use for the S/PDIF interface is to carry compressed digital audio for surround sound as defined by the standard IEC61937. This mode is used to connect the output of a DVD player or computer, via optical or coax, another common use is to carry two channels of uncompressed digital audio from a CD player to an amplifying receiver. S/PDIF was developed at the time as the main standard, AES3. The RCA connectors are typically colour-coded orange to differentiate from other RCA connector uses such as composite video, the cable was also changed from 110 Ω balanced twisted pair to 75 Ω coaxial cable, using RCA jacks. Signals transmitted over consumer-grade TOSLINK connections are identical in content to those transmitted over coaxial connectors, though TOSLINK S/PDIF commonly exhibits higher jitter. S/PDIF is used to digital signals of a number of formats, the most common being the 48 kHz sample rate format. In order to both systems, as well as others that might be needed, the format has no defined data rate. Instead, the data is sent using biphase mark code, which has one or two transitions for every bit, allowing the original word clock to be extracted from the signal itself. S/PDIF is meant to be used for transmitting 20-bit audio data streams plus other related information, to transmit sources with less than 20 bits of sample accuracy, the superfluous bits will be set to zero. S/PDIF can also transport 24-bit samples by way of four bits, however, not all equipment supports this. With one exception, S/PDIF protocol is identical to AES3, the channel status bit differs in S/PDIF. There is one channel status bit in each subframe, making 384 bits in each audio block, the meaning of the channel status bits is completely different between AES3 and S/PDIF
16.
IEC 61400
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IEC61400 is an International Standard published by the International Electrotechnical Commission regarding wind turbines. The 61400 is a set of design made to ensure that wind turbines are appropriately engineered against damage from hazards within the planned lifetime. The standard concerns most aspects of the life from site conditions before construction. Wind turbines are capital intensive, and are purchased before they are being erected and commissioned. IEC started standardizing international certification on the subject in 1995, the common set of standards sometimes replace the various national standards, forming a basis for global certification. Small wind turbines are defined as being of up to 200 m2 swept area and it is also possible to use the IEC 61400-1 standard for turbines of less than 200 m2 swept area. The standards for loads and noise are used in the development of prototypes at the Østerild Wind Turbine Test Field, in the U. S. standards are intended to be compatible with IEC standards, and some parts of 61400 are required documentation. The U. S. National Renewable Energy Laboratory participates in IEC standards development work, an update for IEC61400 is scheduled for 2016. For small wind turbines the global industry has been working towards harmonisation of certification requirements with a test once, Wind turbines are designed for specific conditions. During the construction and design phase assumptions are made about the climate that the wind turbines will be exposed to. Turbine wind class is just one of the factors needing consideration during the process of planning a wind power plant. Wind classes determine which turbine is suitable for the wind conditions of a particular site. Turbine classes are determined by three parameters - the average speed, extreme 50-year gust, and turbulence. Turbulence intensity quantifies how much the wind varies typically within 10 minutes, because the fatigue loads of a number of major components in a wind turbine are mainly caused by turbulence, the knowledge of how turbulent a site is of crucial importance. Normally the wind speed increases with increasing height, in flat terrain the wind speed increases logarithmically with height. In complex terrain the wind profile is not an increase and additionally a separation of the flow might occur. The extreme wind speeds are based on the 3 second average wind speed, turbulence is measured at 15 m/s wind speed. This is the definition in IEC 61400-1 edition 2, for U. S. waters however, several hurricanes have already exceeded wind class Ia with speeds above the 70 m/s, and efforts are being made to provide suitable standards
17.
IEC 61499
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The international standard IEC61499, addressing the topic of function blocks for industrial process measurement and control systems, was initially published in 2005. The specification of IEC61499 defines a model for distributed control systems and is based on the IEC61131 standard. The concepts of IEC61499 are also explained by Lewis and Zoitl as well as Vyatkin, IEC 61499-1 defines the architecture for distributed systems. In IEC61499 the cyclic model of IEC61131 is replaced by an event driven execution model. The event driven execution model allows an explicit specification of the order of function blocks. If necessary, periodically executed applications can be implemented by using the E_CYCLE function block for the generation of events as described in Annex A of IEC 61499-1. All devices within a system are described within a device model, the topology of the system is reflected by the system model. The distribution of an application is described within the mapping model, therefore, applications of a system are distributable but maintained together. Like IEC 61131-3 function blocks, IEC61499 function block types specify both an interface and an implementation, in contrast to IEC 61131-3, an IEC61499 interface contains event inputs and outputs in addition to data inputs and outputs. Events can be associated with data inputs and outputs by WITH constraints, basic function block - BFB, Its functionality is described in terms of an Execution Control Chart, which is similar to a state diagram. Every state can have several actions, each action references one or zero algorithms and one or zero events. Algorithms can be implemented as defined in compliant standards, composite function block - CFB, Its functionality is defined by a function block network. Adapter interfaces, An adapter interface is not a function block. It combines several events and data connections within one connection and provides a concept to separate specification and implementation. Subapplication, Its functionality is defined as a function block network. In contrast to CFBs, subapplications can be distributed, to maintain the applications on a device IEC61499 provides a management model. The device manager maintains the lifecycle of any resource and manages the communication with the software tools via management commands, through the interface of the software tool and the management commands, online reconfiguration of IEC61499 applications can be realized. IEC 61499-2 defines requirements for software tools to be compliant to IEC61499 and this includes requirements for the representation and the portability of IEC61499 elements as well as a DTD format to exchange IEC61499 elements between different software tools
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