title: Jeon So-yeon

text: In the production of "Latata", Jeon began with moombahton beats while considering the other members of the group. For the instruments, she used percussion. After making the beat with simple instruments, she put it on loop and coated it with melody. She described her process in composing started with writing beats and melodies on a blank page with just a piano or a beat. She continued explaining that "it is common to have a track maker, someone who writes melodies and putting a melody on a mostly completed beat." She confessed she avoids the words "me or I" in lyrics. Jeon emphasized the importance of appealing to emotions, saying, "I think it's because I'm making music without prejudice. There are various performances, but I think it's the music that anyone can sympathize with. Our group is multinational and has no language barrier."


title: Jeon So-yeon

text: In "Queendom"<nowiki>'</nowiki>s first preliminary performance, Jeon proposed a sorceress concept of "Latata". In music critics IZM's words, it "does not look like the a rearranged version, but more like an entirely original song". The article also mentioned the reason she can consistently being confident about her team, song and herself both on and off stage is because "she has a clear image of what she wants to create." Poet Seo Hyo-in wrote that "Soyeon covers all aspects of producing, from composition and writing, rap making and setting the concept. However, she doesn't overshadow the other members." She praised Jeon for maximising the strengths of each member and allows them to find their own artistic freedom.


title: Jeon So-yeon

text: Jeon believes that women can be producers as well and hoped that more women would come out as producers. She believes that there are no boundaries when it comes to arts forms like music, performances and gaming. "When I write, I don't think about gender. No "we're a girl group", women, men or age. I just write what's on my mind." In a June 2020 interview with MTV, Jeon discussed using the word 'she' in "Oh My God" stating, "I didn't want to limit that 'she' to a certain being or a certain definition, so it's open to anything. I believe that all kinds of love are valuable and must be respected."


title: Simon Russell Beale

text: Sir Simon Russell Beale (born 12 January 1961) is an English actor. He is known for his appearances in film, television and theatre, and work on radio, on audiobooks and as a narrator. For his services to drama, he was knighted by Queen Elizabeth II at Buckingham Palace in 2019.


title: Simon Russell Beale

text: He has spent much of his theatre career working in productions for both the Royal Shakespeare Company and National Theatre. He has received ten Laurence Olivier Award nominations, winning three awards for his performances in "Volpone" (1996), "Candide" (2000), and "Uncle Vanya" (2003). For his work on the Broadway stage he has received a Tony Award for Best Actor in a Play nomination for his performance as George in the Tom Stoppard play "Jumpers" in 2004. For his role as Henry Lehman in "The Lehman Trilogy", he won the Tony Award for Best Actor in a Play and was nominated for an Olivier Award. Beale has been described by "The Independent" as "the greatest stage actor of his generation".


title: Simon Russell Beale

text: Beale made his film debut in Sally Potter's period drama "Orlando" (1992). He continued acting in films such as "Persuasion" (1995), "Hamlet" (1996), "My Week with Marilyn" (2011), "The Deep Blue Sea" (2011), "Into the Woods" (2014), and "Mary Queen of Scots" (2018). In 2017, he starred in Armando Iannucci's dark comedy "The Death of Stalin" playing Lavrentiy Beria for which he received the British Independent Film Award for Best Supporting Actor. He has also appeared in the television projects "The Young Visiters" (2003), "Dunkirk" (2004), and as Falstaff in the BBC made-for-television films "Henry IV, Part I and Part II" (2012). He was part of the main cast of Showtime's "Penny Dreadful".


title: Simon Russell Beale

text: Beale was born on 12 January 1961, one of six children of Captain, later Lieutenant General, Sir Peter Beale and his wife Julia "née" Winter. He was born in Penang, Malaya, where his father was serving in the Army Medical Services. His father later, from 1991 to 1994, served as Surgeon-General of HM Armed Forces. Several other members of Beale's family have pursued successful careers in medicine.


title: Simon Russell Beale

text: Beale was first drawn to performance when, at the age of eight, he became a chorister at St. Paul's Cathedral and a pupil at the adjoining St Paul's Cathedral School. His secondary education was undertaken at the independent Clifton College in Bristol.


title: Simon Russell Beale

text: His first stage performance was as Hippolyta in "A Midsummer Night's Dream" at primary school. In the sixth form at Clifton he also performed in "Rosencrantz and Guildenstern Are Dead", a play in which he would later star at the National Theatre.


title: Simon Russell Beale

text: After Clifton, he went to Gonville and Caius College, Cambridge, and obtained a first in English, after which he was offered a place to undertake a PhD. He pursued further studies at Guildhall School of Music and Drama, graduating in 1983.


title: Simon Russell Beale

text: Beale first came to the attention of theatre-goers in the late 1980s with a series of lauded comic performances, which were on occasion extremely camp, in such plays as "The Man of Mode" by George Etherege and "Restoration" by Edward Bond at the Royal Shakespeare Company (RSC). He broadened his range in the early 1990s with moving performances as Konstantin in Chekhov's "The Seagull", as Oswald in Ibsen's "Ghosts", Ferdinand in "The Duchess of Malfi" and as Edgar in "King Lear". At the first annual Ian Charleson Awards in January 1991, he received a special commendation for his 1990 performances of Konstantin in "The Seagull", Thersites in "Troilus and Cressida" and Edward II in "Edward II", all at the RSC.


title: Simon Russell Beale

text: It was at the RSC that he first worked with Sam Mendes, who directed him as Thersites in "Troilus and Cressida", as "Richard III" and as Ariel in "The Tempest", in the last of which he revealed a fine tenor voice. Mendes also directed him as Iago in "Othello" at the Royal National Theatre and in Mendes's farewell productions at the Donmar Warehouse in 2002, Chekhov's "Uncle Vanya", in which Beale played the title role, and "Twelfth Night", in which he played Malvolio. He won the 2003 Laurence Olivier Award for "Uncle Vanya".


title: Simon Russell Beale

text: Since 1995, he has been a regular at the National Theatre, where his roles have included Mosca in Ben Jonson's "Volpone" opposite Michael Gambon, George in Tom Stoppard's "Jumpers" and the lead in "Humble Boy" by Charlotte Jones, a part written specially for him. In 1997, he played the pivotal role of Kenneth Widmerpool in a television adaptation of Anthony Powell's "A Dance to the Music of Time", for which he won the Best Actor award at the British Academy Television Awards in 1998. The following year, he was a key part of Trevor Nunn's ensemble, playing in Leonard Bernstein's "Candide" (Voltaire/Pangloss), Edward Bulwer-Lytton's "Money" and Maxim Gorky's "Summerfolk" at the National. In autumn 2006, he played Galileo in David Hare's adaption of Brecht's "Life of Galileo" and as Face in "The Alchemist".


title: Simon Russell Beale

text: In 2000, he played Hamlet in a production directed by John Caird for the National Theatre, a role for which he was described by "The Daily Telegraph" as "portly [and] relatively long in the tooth". In 2005, Beale was directed by Deborah Warner as Cassius in "Julius Caesar" alongside Ralph Fiennes as Antony. That same year, he played the title role in "Macbeth" at the Almeida Theatre. In 2007, he reprised his 2005 Broadway role as King Arthur in the Monty Python musical "Spamalot" at the Palace Theatre, London.


title: Simon Russell Beale

text: From December 2007 to March 2008, he played Benedick in "Much Ado About Nothing" directed by Nicholas Hytner at the National Theatre and from February to July 2008, he played Andrew Undershaft in Hytner's production of Shaw's "Major Barbara"; he then appeared in Harold Pinter's "A Slight Ache" and "Landscape".


title: Simon Russell Beale

text: In 2008, he made his debut as a television presenter, fronting the BBC series "Sacred Music" with Harry Christophers and The Sixteen. Various specials and a second series have since been produced; the most recent episode "(Monteverdi in Mantua: The Genius of the Vespers)" was broadcast in 2015. In spring 2009, Beale and Sam Mendes collaborated on "The Winter's Tale" and "The Cherry Orchard", in which Beale played Leontes and Lopakhin respectively, at the Brooklyn Academy of Music, later transferring to the Old Vic Theatre.


title: Simon Russell Beale

text: From 2009 to 2010, he played George Smiley in the BBC Radio 4 adaptation of all the John le Carré novels in which Smiley featured. These were broadcast in nineteen 90-minute or 60-minute full cast radio plays. From March to June 2010, he played Sir Harcourt Courtly in "London Assurance", again at the National. In August 2010, he appeared in the first West End revival of "Deathtrap" by Ira Levin. In March 2011, he made his debut with The Royal Ballet in "Alice's Adventures in Wonderland" as the Duchess. In October 2011, he returned to the National to star as Joseph Stalin in the premiere of "Collaborators", for which he won Best Actor at the 2012 Evening Standard Awards.


title: Simon Russell Beale

text: In 2010–11, Beale played the Coalition Home Secretary William Towers in the two final series of BBC One's spy drama, "Spooks". He played the title role in "Timon of Athens" at the National Theatre from July to October 2012. The production was broadcast to cinemas around the world (as was "Collaborators" earlier) on 1 November 2012 through the National Theatre Live programme. He starred in a revival of Peter Nichols' "Privates on Parade" as part of Michael Grandage's new West End season at the Noël Coward Theatre from December 2012 to March 2013.


title: Simon Russell Beale

text: In 2013, he won the British Academy Television Award (BAFTA) for Best Supporting Actor for his performance as Falstaff in the BBC's The Hollow Crown series of TV films about Shakespeare's historical dramas "Richard II"; "Henry IV, Part 1;" "Henry IV, Part 2;" and "Henry V". That same year he appeared in "" (2013).


title: Simon Russell Beale

text: Beale appeared alongside John Simm in Harold Pinter's "The Hothouse" at the Trafalgar Studios from May to August 2013, directed by Jamie Lloyd. From January 2014, he played the title role in "King Lear" at the National Theatre, directed once again by Sam Mendes. Also from 2014 to 2016 he starred as a main cast member in Showtime's "Penny Dreadful", in which he played an eccentric Egyptologist. In 2014, Beale was appointed the Cameron Mackintosh Professor of Contemporary Theatre at Oxford University, based at St Catherine's College.


title: Simon Russell Beale

text: From May to July 2015, he starred in "Temple", a new play at the Donmar Warehouse about the 2011 United Kingdom anti-austerity protests. In September and October 2015, he played Samuel Foote in "Mr Foote's Other Leg" at the Hampstead Theatre. It transferred to the Theatre Royal Haymarket from October 2015 to January 2016.


title: Simon Russell Beale

text: In November 2016, Beale returned to the Royal Shakespeare Company in Stratford-upon-Avon, to play Prospero in "The Tempest". In June 2017, it transferred to the Barbican Centre in London. In July 2018, Beale returned to the National, starring opposite Ben Miles and Adam Godley in "The Lehman Trilogy", again directed by Mendes. It transferred to the Piccadilly Theatre in the West End in May 2019. Beale starred in the title role of "Richard II" at the Almeida Theatre from December 2018 to February 2019.


title: Simon Russell Beale

text: During the COVID-19 pandemic, Beale contributed as a guest speaker to "The Show Must Go Online's" performance of "Timon of Athens".


title: Simon Russell Beale

text: In the summer of 2021, Beale played JS Bach in the world première of Nina Raine's "Bach and Sons", directed by frequent collaborator Nicholas Hytner at his company's Bridge Theatre in London.


title: Simon Russell Beale

text: During this time he re-rehearsed for the post-COVID return in late September of the Broadway transfer of the National Theatre production of "The Lehman Trilogy" whose run had been halted on 12 March 2020 by the pandemic. Beale reprised his role (along with Adam Godley) but, due to stage commitments in London for the RSC in the third part of the "Wolf Hall" trilogy, Ben Miles was replaced by Adrian Lester. Beale won a Tony Award for "The Lehman Trilogy".


title: Simon Russell Beale

text: Beale is a past president of the Anthony Powell Society, a tribute to his portrayal of Kenneth Widmerpool.


title: Simon Russell Beale

text: Beale is gay. In the "Independent on Sunday" 2006 Pink List – a list of the most influential gay men and women in the UK – he was placed at number 30.


title: Business intelligence

text: Business intelligence (BI) comprises the strategies and technologies used by enterprises for the data analysis and management of business information. Common functions of business intelligence technologies include reporting, online analytical processing, analytics, dashboard development, data mining, process mining, complex event processing, business performance management, benchmarking, text mining, predictive analytics, and prescriptive analytics.


title: Business intelligence

text: BI tools can handle large amounts of structured and sometimes unstructured data to help identify, develop, and otherwise create new strategic business opportunities. They aim to allow for the easy interpretation of these big data. Identifying new opportunities and implementing an effective strategy based on insights can provide businesses with a competitive market advantage and long-term stability, and help them take strategic decisions.


title: Business intelligence

text: Business intelligence can be used by enterprises to support a wide range of business decisions ranging from operational to strategic. Basic operating decisions include product positioning or pricing. Strategic business decisions involve priorities, goals, and directions at the broadest level. In all cases, BI is most effective when it combines data derived from the market in which a company operates (external data) with data from company sources internal to the business such as financial and operations data (internal data). When combined, external and internal data can provide a complete picture which, in effect, creates an "intelligence" that cannot be derived from any singular set of data.


title: Business intelligence

text: Among myriad uses, business intelligence tools empower organizations to gain insight into new markets, to assess demand and suitability of products and services for different market segments, and to gauge the impact of marketing efforts.


title: Business intelligence

text: BI applications use data gathered from a data warehouse (DW) or from a data mart, and the concepts of BI and DW combine as "BI/DW"


title: Business intelligence

text: The earliest known use of the term "business intelligence" is in Richard Millar Devens' "Cyclopædia of Commercial and Business Anecdotes" (1865). Devens used the term to describe how the banker Sir Henry Furnese gained profit by receiving and acting upon information about his environment, prior to his competitors:


title: Business intelligence

text: The ability to collect and react accordingly based on the information retrieved, Devens says, is central to business intelligence.


title: Business intelligence

text: When Hans Peter Luhn, a researcher at IBM, used the term "business intelligence" in an article published in 1958, he employed the "Webster's Dictionary" definition of intelligence: "the ability to apprehend the interrelationships of presented facts in such a way as to guide action towards a desired goal."


title: Business intelligence

text: In 1989, Howard Dresner (later a Gartner analyst) proposed "business intelligence" as an umbrella term to describe "concepts and methods to improve business decision making by using fact-based support systems." It was not until the late 1990s that this usage was widespread.


title: Business intelligence

text: Critics see BI merely as an evolution of business reporting together with the advent of increasingly powerful and easy-to-use data analysis tools. In this respect, it has also been criticized as a marketing buzzword in the context of the "big data" surge.


title: Business intelligence

text: According to Solomon Negash and Paul Gray, business intelligence (BI) can be defined as systems that combine:


title: Business intelligence

text: with analysis to evaluate complex corporate and competitive information for presentation to planners and decision makers, with the objective of improving the timeliness and the quality of the input to the decision process."


title: Business intelligence

text: According to Forrester Research, business intelligence is "a set of methodologies, processes, architectures, and technologies that transform raw data into meaningful and useful information used to enable more effective strategic, tactical, and operational insights and decision-making." Under this definition, business intelligence encompasses information management (data integration, data quality, data warehousing, master-data management, text- and content-analytics, et al.). Therefore, Forrester refers to "data preparation" and "data usage" as two separate but closely linked segments of the business-intelligence architectural stack.


title: Business intelligence

text: Forrester distinguishes this from the "business-intelligence market", which is "just the top layers of the BI architectural stack, such as reporting, analytics, and dashboards."


title: Business intelligence

text: Though the term business intelligence is sometimes a synonym for competitive intelligence (because they both support decision making), BI uses technologies, processes, and applications to analyze mostly internal, structured data and business processes while competitive intelligence gathers, analyzes, and disseminates information with a topical focus on company competitors. If understood broadly, business intelligence can be considered as a subset of competitive intelligence.


title: Business intelligence

text: Business intelligence and business analytics are sometimes used interchangeably, but there are alternate definitions. Thomas Davenport, professor of information technology and management at Babson College argues that business intelligence should be divided into querying, reporting, Online analytical processing (OLAP), an "alerts" tool, and business analytics. In this definition, business analytics is the subset of BI focusing on statistics, prediction, and optimization, rather than the reporting functionality.


title: Business intelligence

text: Business operations can generate a very large amount of data in the form of e-mails, memos, notes from call-centers, news, user groups, chats, reports, web-pages, presentations, image-files, video-files, and marketing material. According to Merrill Lynch, more than 85% of all business information exists in these forms; a company might only use such a document a single time. Because of the way it is produced and stored, this information is either unstructured or semi-structured.


title: Business intelligence

text: The management of semi-structured data is an unsolved problem in the information technology industry. According to projections from Gartner (2003), white-collar workers spend 30–40% of their time searching, finding, and assessing unstructured data. BI uses both structured and unstructured data. The former is easy to search, and the latter contains a large quantity of the information needed for analysis and decision-making. Because of the difficulty of properly searching, finding, and assessing unstructured or semi-structured data, organizations may not draw upon these vast reservoirs of information, which could influence a particular decision, task, or project. This can ultimately lead to poorly informed decision-making.


title: Business intelligence

text: Therefore, when designing a business intelligence/DW-solution, the specific problems associated with semi-structured and unstructured data must be accommodated for as well as those for the structured data.


title: Business intelligence

text: Unstructured and semi-structured data have different meanings depending on their context. In the context of relational database systems, unstructured data cannot be stored in predictably ordered columns and rows. One type of unstructured data is typically stored in a BLOB (binary large object), a catch-all data type available in most relational database management systems. Unstructured data may also refer to irregularly or randomly repeated column patterns that vary from row to row or files of natural language that do not have detailed metadata.


title: Business intelligence

text: Many of these data types, however, like e-mails, word processing text files, PDFs, PPTs, image-files, and video-files conform to a standard that offers the possibility of metadata. Metadata can include information such as author and time of creation, and this can be stored in a relational database. Therefore, it may be more accurate to talk about this as semi-structured documents or data, but no specific consensus seems to have been reached.


title: Business intelligence

text: Unstructured data can also simply be the knowledge that business users have about future business trends. Business forecasting naturally aligns with the BI system because business users think of their business in aggregate terms. Capturing the business knowledge that may only exist in the minds of business users provides some of the most important data points for a complete BI solution.


title: Business intelligence

text: There are several challenges to developing BI with semi-structured data. According to Inmon & Nesavich, some of those are:


title: Business intelligence

text: To solve problems with searchability and assessment of data, it is necessary to know something about the content. This can be done by adding context through the use of metadata. Many systems already capture some metadata (e.g. filename, author, size, etc.), but more useful would be metadata about the actual content – e.g. summaries, topics, people, or companies mentioned. Two technologies designed for generating metadata about content are automatic categorization and information extraction.


title: Business intelligence

text: In a 2013 report, Gartner categorized business intelligence vendors as either an independent "pure-play" vendor or a consolidated "mega-vendor". In 2019, the BI market was shaken within Europe for the new legislation of GDPR (General Data Protection Regulation) which puts the responsibility of data collection and storage onto the data user with strict laws in place to make sure the data is compliant. Growth within Europe has steadily increased since May 2019 when GDPR was brought. The legislation refocused companies to look at their own data from a compliance perspective but also revealed future opportunities using personalization and external BI providers to increase market share.


title: Amplifier

text: An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It may increase the power significantly, or its main effect may be to boost the voltage or current (power, voltage or current amplifier). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude of a signal applied to its input terminals, producing a greater amplitude signal at its output. The ratio of output to input voltage, current, or power is termed gain (voltage, current, or power gain). An amplifier, by definition has gain greater than unity (if the gain is less than unity, the device is an attenuator).


title: Amplifier

text: An amplifier can either be a separate piece of equipment or an electrical circuit contained within another device. Amplification is fundamental to modern electronics, and amplifiers are widely used in almost all electronic equipment. Amplifiers can be categorized in different ways. One is by the frequency of the electronic signal being amplified. For example, audio amplifiers amplify signals in the audio (sound) range of less than 20 kHz, RF amplifiers amplify frequencies in the radio frequency range between 20 kHz and 300 GHz, and servo amplifiers and instrumentation amplifiers may work with very low frequencies down to direct current. Amplifiers can also be categorized by their physical placement in the signal chain; a preamplifier may precede other signal processing stages, for example. The first practical electrical device which could amplify was the triode vacuum tube, invented in 1906 by Lee De Forest, which led to the first amplifiers around 1912. Today most amplifiers use transistors.


title: Amplifier

text: The first practical prominent device that could amplify was the triode vacuum tube, invented in 1906 by Lee De Forest, which led to the first amplifiers around 1912. Vacuum tubes were used in almost all amplifiers until the 1960s–1970s when transistors replaced them. Today, most amplifiers use transistors, but vacuum tubes continue to be used in some applications.


title: Amplifier

text: The development of audio communication technology in form of the telephone, first patented in 1876, created the need to increase the amplitude of electrical signals to extend the transmission of signals over increasingly long distances. In telegraphy, this problem had been solved with intermediate devices at stations that replenished the dissipated energy by operating a signal recorder and transmitter back-to-back, forming a relay, so that a local energy source at each intermediate station powered the next leg of transmission.


title: Amplifier

text: For duplex transmission, i.e. sending and receiving in both directions, bi-directional relay repeaters were developed starting with the work of C. F. Varley for telegraphic transmission. Duplex transmission was essential for telephony and the problem was not satisfactorily solved until 1904, when H. E. Shreeve of the American Telephone and Telegraph Company improved existing attempts at constructing a telephone repeater consisting of back-to-back carbon-granule transmitter and electrodynamic receiver pairs. The Shreeve repeater was first tested on a line between Boston and Amesbury, MA, and more refined devices remained in service for some time. After the turn of the century it was found that negative resistance mercury lamps could amplify, and were also tried in repeaters, with little success.


title: Amplifier

text: The development of thermionic valves starting around 1902, provided an entirely electronic method of amplifying signals. The first practical version of such devices was the Audion triode, invented in 1906 by Lee De Forest, which led to the first amplifiers around 1912. Since the only previous device which was widely used to strengthen a signal was the relay used in telegraph systems, the amplifying vacuum tube was first called an "electron relay". The terms "amplifier" and "amplification", derived from the Latin "amplificare", ("to enlarge or expand"), were first used for this new capability around 1915 when triodes became widespread.


title: Amplifier

text: The amplifying vacuum tube revolutionized electrical technology, creating the new field of electronics, the technology of active electrical devices. It made possible long-distance telephone lines, public address systems, radio broadcasting, talking motion pictures, practical audio recording, radar, television, and the first computers. For 50 years virtually all consumer electronic devices used vacuum tubes. Early tube amplifiers often had positive feedback (regeneration), which could increase gain but also make the amplifier unstable and prone to oscillation. Much of the mathematical theory of amplifiers was developed at Bell Telephone Laboratories during the 1920s to 1940s. Distortion levels in early amplifiers were high, usually around 5%, until 1934, when Harold Black developed negative feedback; this allowed the distortion levels to be greatly reduced, at the cost of lower gain. Other advances in the theory of amplification were made by Harry Nyquist and Hendrik Wade Bode.


title: Amplifier

text: The vacuum tube was virtually the only amplifying device, other than specialized power devices such as the magnetic amplifier and amplidyne, for 40 years. Power control circuitry used magnetic amplifiers until the latter half of the twentieth century when power semiconductor devices became more economical, with higher operating speeds. The old Shreeve electroacoustic carbon repeaters were used in adjustable amplifiers in telephone subscriber sets for the hearing impaired until the transistor provided smaller and higher quality amplifiers in the 1950s.


title: Amplifier

text: The first working transistor was a point-contact transistor invented by John Bardeen and Walter Brattain in 1947 at Bell Labs, where William Shockley later invented the bipolar junction transistor (BJT) in 1948. They were followed by the invention of the metal-oxide-semiconductor field-effect transistor (MOSFET) by Mohamed M. Atalla and Dawon Kahng at Bell Labs in 1959. Due to MOSFET scaling, the ability to scale down to increasingly small sizes, the MOSFET has since become the most widely used amplifier.


title: Amplifier

text: The replacement of bulky electron tubes with transistors during the 1960s and 1970s created a revolution in electronics, making possible a large class of portable electronic devices, such as the transistor radio developed in 1954. Today, use of vacuum tubes is limited for some high power applications, such as radio transmitters.


title: Amplifier

text: Beginning in the 1970s, more and more transistors were connected on a single chip thereby creating higher scales of integration (such as small-scale, medium-scale and large-scale integration) in integrated circuits. Many amplifiers commercially available today are based on integrated circuits.


title: Amplifier

text: For special purposes, other active elements have been used. For example, in the early days of the satellite communication, parametric amplifiers were used. The core circuit was a diode whose capacitance was changed by an RF signal created locally. Under certain conditions, this RF signal provided energy that was modulated by the extremely weak satellite signal received at the earth station.


title: Amplifier

text: Advances in digital electronics since the late 20th century provided new alternatives to the traditional linear-gain amplifiers by using digital switching to vary the pulse-shape of fixed amplitude signals, resulting in devices such as the Class-D amplifier.


title: Amplifier

text: In principle, an amplifier is an electrical two-port network that produces a signal at the output port that is a replica of the signal applied to the input port, but increased in magnitude.


title: Amplifier

text: The input port can be idealized as either being a voltage input, which takes no current, with the output proportional to the voltage across the port; or a current input, with no voltage across it, in which the output is proportional to the current through the port. The output port can be idealized as being either a dependent voltage source, with zero source resistance and its output voltage dependent on the input; or a dependent current source, with infinite source resistance and the output current dependent on the input. Combinations of these choices lead to four types of ideal amplifiers. In idealized form they are represented by each of the four types of dependent source used in linear analysis, as shown in the figure, namely:


title: Amplifier

text: Each type of amplifier in its ideal form has an ideal input and output resistance that is the same as that of the corresponding dependent source:


title: Amplifier

text: In real amplifiers the ideal impedances are not possible to achieve, but these ideal elements can be used to construct equivalent circuits of real amplifiers by adding impedances (resistance, capacitance and inductance) to the input and output. For any particular circuit, a small-signal analysis is often used to find the actual impedance. A small-signal AC test current "I" is applied to the input or output node, all external sources are set to AC zero, and the corresponding alternating voltage "V" across the test current source determines the impedance seen at that node as "R = V / I".


title: Amplifier

text: Amplifiers designed to attach to a transmission line at input and output, especially RF amplifiers, do not fit into this classification approach. Rather than dealing with voltage or current individually, they ideally couple with an input or output impedance matched to the transmission line impedance, that is, match "ratios" of voltage to current. Many real RF amplifiers come close to this ideal. Although, for a given appropriate source and load impedance, RF amplifiers can be characterized as amplifying voltage or current, they fundamentally are amplifying power.


title: Amplifier

text: Amplifiers are described according to the properties of their inputs, their outputs, and how they relate. All amplifiers have gain, a multiplication factor that relates the magnitude of some property of the output signal to a property of the input signal. The gain may be specified as the ratio of output voltage to input voltage (voltage gain), output power to input power (power gain), or some combination of current, voltage, and power. In many cases the property of the output that varies is dependent on the same property of the input, making the gain unitless (though often expressed in decibels (dB)).


title: Amplifier

text: Most amplifiers are designed to be linear. That is, they provide constant gain for any normal input level and output signal. If an amplifier's gain is not linear, the output signal can become distorted. There are, however, cases where variable gain is useful. Certain signal processing applications use exponential gain amplifiers.


title: Amplifier

text: Amplifiers are usually designed to function well in a specific application, for example: radio and television transmitters and receivers, high-fidelity ("hi-fi") stereo equipment, microcomputers and other digital equipment, and guitar and other instrument amplifiers. Every amplifier includes at least one active device, such as a vacuum tube or transistor.


title: Amplifier

text: Negative feedback is a technique used in most modern amplifiers to improve bandwidth and distortion and control gain. In a negative feedback amplifier part of the output is fed back and added to the input in opposite phase, subtracting from the input. The main effect is to reduce the overall gain of the system. However, any unwanted signals introduced by the amplifier, such as distortion are also fed back. Since they are not part of the original input, they are added to the input in opposite phase, subtracting them from the input. In this way, negative feedback also reduces nonlinearity, distortion and other errors introduced by the amplifier. Large amounts of negative feedback can reduce errors to the point that the response of the amplifier itself becomes almost irrelevant as long as it has a large gain, and the output performance of the system (the "closed loop performance") is defined entirely by the components in the feedback loop. This technique is particularly used with operational amplifiers (op-amps).


title: Amplifier

text: Non-feedback amplifiers can only achieve about 1% distortion for audio-frequency signals. With negative feedback, distortion can typically be reduced to 0.001%. Noise, even crossover distortion, can be practically eliminated. Negative feedback also compensates for changing temperatures, and degrading or nonlinear components in the gain stage, but any change or nonlinearity in the components in the feedback loop will affect the output. Indeed, the ability of the feedback loop to define the output is used to make active filter circuits.


title: Amplifier

text: Another advantage of negative feedback is that it extends the bandwidth of the amplifier. The concept of feedback is used in operational amplifiers to precisely define gain, bandwidth, and other parameters entirely based on the components in the feedback loop.


title: Amplifier

text: Negative feedback can be applied at each stage of an amplifier to stabilize the operating point of active devices against minor changes in power-supply voltage or device characteristics.


title: Amplifier

text: Some feedback, positive or negative, is unavoidable and often undesirable—introduced, for example, by parasitic elements, such as inherent capacitance between input and output of devices such as transistors, and capacitive coupling of external wiring. Excessive frequency-dependent positive feedback can produce parasitic oscillation and turn an amplifier into an oscillator.


title: Amplifier

text: All amplifiers include some form of active device: this is the device that does the actual amplification. The active device can be a vacuum tube, discrete solid state component, such as a single transistor, or part of an integrated circuit, as in an op-amp).


title: Amplifier

text: Transistor amplifiers (or solid state amplifiers) are the most common type of amplifier in use today. A transistor is used as the active element. The gain of the amplifier is determined by the properties of the transistor itself as well as the circuit it is contained within.


title: Amplifier

text: Common active devices in transistor amplifiers include bipolar junction transistors (BJTs) and metal oxide semiconductor field-effect transistors (MOSFETs).


title: Amplifier

text: Applications are numerous, some common examples are audio amplifiers in a home stereo or public address system, RF high power generation for semiconductor equipment, to RF and microwave applications such as radio transmitters.


title: Amplifier

text: Transistor-based amplification can be realized using various configurations: for example a bipolar junction transistor can realize common base, common collector or common emitter amplification; a MOSFET can realize common gate, common source or common drain amplification. Each configuration has different characteristics.


title: Amplifier

text: Vacuum-tube amplifiers (also known as tube amplifiers or valve amplifiers) use a vacuum tube as the active device. While semiconductor amplifiers have largely displaced valve amplifiers for low-power applications, valve amplifiers can be much more cost effective in high power applications such as radar, countermeasures equipment, and communications equipment. Many microwave amplifiers are specially designed valve amplifiers, such as the klystron, gyrotron, traveling wave tube, and crossed-field amplifier, and these microwave valves provide much greater single-device power output at microwave frequencies than solid-state devices. Vacuum tubes remain in use in some high end audio equipment, as well as in musical instrument amplifiers, due to a preference for "tube sound".


title: Amplifier

text: Magnetic amplifiers are devices somewhat similar to a transformer where one winding is used to control the saturation of a magnetic core and hence alter the impedance of the other winding.


title: Amplifier

text: They have largely fallen out of use due to development in semiconductor amplifiers but are still useful in HVDC control, and in nuclear power control circuitry due to not being affected by radioactivity.


title: Amplifier

text: A power amplifier is an amplifier designed primarily to increase the power available to a load. In practice, amplifier power gain depends on the source and load impedances, as well as the inherent voltage and current gain. A radio frequency (RF) amplifier design typically optimizes impedances for power transfer, while audio and instrumentation amplifier designs normally optimize input and output impedance for least loading and highest signal integrity. An amplifier that is said to have a gain of 20 dB might have a voltage gain of 20 dB and an available power gain of much more than 20 dB (power ratio of 100)—yet actually deliver a much lower power gain if, for example, the input is from a 600 Ω microphone and the output connects to a 47 kΩ input socket for a power amplifier. In general, the power amplifier is the last 'amplifier' or actual circuit in a signal chain (the output stage) and is the amplifier stage that requires attention to power efficiency. Efficiency considerations lead to the various classes of power amplifiers based on the biasing of the output transistors or tubes: see power amplifier classes below.


title: Amplifier

text: Audio power amplifiers are typically used to drive loudspeakers. They will often have two output channels and deliver equal power to each. An RF power amplifier is found in radio transmitter final stages. A Servo motor controller: amplifies a control voltage to adjust the speed of a motor, or the position of a motorized system.


title: Amplifier

text: An operational amplifier is an amplifier circuit which typically has very high open loop gain and differential inputs. Op amps have become very widely used as standardized "gain blocks" in circuits due to their versatility; their gain, bandwidth and other characteristics can be controlled by feedback through an external circuit. Though the term today commonly applies to integrated circuits, the original operational amplifier design used valves, and later designs used discrete transistor circuits.


title: Amplifier

text: A fully differential amplifier is similar to the operational amplifier, but also has differential outputs. These are usually constructed using BJTs or FETs.


title: Amplifier

text: These use balanced transmission lines to separate individual single stage amplifiers, the outputs of which are summed by the same transmission line. The transmission line is a balanced type with the input at one end and on one side only of the balanced transmission line and the output at the opposite end is also the opposite side of the balanced transmission line. The gain of each stage adds linearly to the output rather than multiplies one on the other as in a cascade configuration. This allows a higher bandwidth to be achieved than could otherwise be realised even with the same gain stage elements.


title: Amplifier

text: These nonlinear amplifiers have much higher efficiencies than linear amps, and are used where the power saving justifies the extra complexity. Class-D amplifiers are the main example of this type of amplification.


title: Amplifier

text: Negative Resistance Amplifier is a type of Regenerative Amplifier that can use the feedback between the transistor's source and gate to transform a capacitive impedance on the transistor's source to a negative resistance on its gate. Compared to other types of amplifiers, this "negative resistance amplifier" will only require a tiny amount of power to achieve very high gain, maintaining a good noise figure at the same time.


title: Amplifier

text: Video amplifiers are designed to process video signals and have varying bandwidths depending on whether the video signal is for SDTV, EDTV, HDTV 720p or 1080i/p etc.. The specification of the bandwidth itself depends on what kind of filter is used—and at which point ( or for example) the bandwidth is measured. Certain requirements for step response and overshoot are necessary for an acceptable TV image.


title: Amplifier

text: Traveling wave tube amplifiers (TWTAs) are used for high power amplification at low microwave frequencies. They typically can amplify across a broad spectrum of frequencies; however, they are usually not as tunable as klystrons.


title: Amplifier

text: Klystrons are specialized linear-beam vacuum-devices, designed to provide high power, widely tunable amplification of millimetre and sub-millimetre waves. Klystrons are designed for large scale operations and despite having a narrower bandwidth than TWTAs, they have the advantage of coherently amplifying a reference signal so its output may be precisely controlled in amplitude, frequency and phase.


title: Amplifier

text: Solid-state devices such as silicon short channel MOSFETs like double-diffused metal-oxide-semiconductor (DMOS) FETs, GaAs FETs, SiGe and GaAs heterojunction bipolar transistors/HBTs, HEMTs, IMPATT diodes, and others, are used especially at lower microwave frequencies and power levels on the order of watts specifically in applications like portable RF terminals/cell phones and access points where size and efficiency are the drivers. New materials like gallium nitride (GaN) or GaN on silicon or on silicon carbide/SiC are emerging in HEMT transistors and applications where improved efficiency, wide bandwidth, operation roughly from few to few tens of GHz with output power of few Watts to few hundred of Watts are needed.


title: Amplifier

text: Depending on the amplifier specifications and size requirements microwave amplifiers can be realised as monolithically integrated, integrated as modules or based on discrete parts or any combination of those.


title: Amplifier

text: Instrument amplifiers are a range of audio power amplifiers used to increase the sound level of musical instruments, for example guitars, during performances.


title: Amplifier

text: One set of classifications for amplifiers is based on which device terminal is common to both the input and the output circuit. In the case of bipolar junction transistors, the three classes are common emitter, common base, and common collector. For field-effect transistors, the corresponding configurations are common source, common gate, and common drain; for vacuum tubes, common cathode, common grid, and common plate.


title: Amplifier

text: The common emitter (or common source, common cathode, etc.) is most often configured to provide amplification of a voltage applied between base and emitter, and the output signal taken between collector and emitter is inverted, relative to the input. The common collector arrangement applies the input voltage between base and collector, and to take the output voltage between emitter and collector. This causes negative feedback, and the output voltage tends to follow the input voltage. This arrangement is also used as the input presents a high impedance and does not load the signal source, though the voltage amplification is less than one. The common-collector circuit is, therefore, better known as an emitter follower, source follower, or cathode follower.


title: Amplifier

text: An amplifier whose output exhibits no feedback to its input side is described as 'unilateral'. The input impedance of a unilateral amplifier is independent of load, and output impedance is independent of signal source impedance.


title: Amplifier

text: An amplifier that uses feedback to connect part of the output back to the input is a "bilateral" amplifier. Bilateral amplifier input impedance depends on the load, and output impedance on the signal source impedance.


title: Amplifier

text: All amplifiers are bilateral to some degree; however they may often be modeled as unilateral under operating conditions where feedback is small enough to neglect for most purposes, simplifying analysis (see the common base article for an example).


title: Amplifier

text: Another way to classify amplifiers is by the phase relationship of the input signal to the output signal. An 'inverting' amplifier produces an output 180 degrees out of phase with the input signal (that is, a polarity inversion or mirror image of the input as seen on an oscilloscope). A 'non-inverting' amplifier maintains the phase of the input signal waveforms. An emitter follower is a type of non-inverting amplifier, indicating that the signal at the emitter of a transistor is following (that is, matching with unity gain but perhaps an offset) the input signal. Voltage follower is also non inverting type of amplifier having unity gain.


title: Amplifier

text: Other amplifiers may be classified by their function or output characteristics. These functional descriptions usually apply to complete amplifier systems or sub-systems and rarely to individual stages.


title: Amplifier

text: Amplifiers are sometimes classified by the coupling method of the signal at the input, output, or between stages. Different types of these include:


title: Amplifier

text: Depending on the frequency range and other properties amplifiers are designed according to different principles.


title: Amplifier

text: Frequency ranges down to DC are only used when this property is needed. Amplifiers for direct current signals are vulnerable to minor variations in the properties of components with time. Special methods, such as chopper stabilized amplifiers are used to prevent objectionable drift in the amplifier's properties for DC. "DC-blocking" capacitors can be added to remove DC and sub-sonic frequencies from audio amplifiers.


title: Amplifier

text: Depending on the frequency range specified different design principles must be used. Up to the MHz range only "discrete" properties need be considered; e.g., a terminal has an input impedance.


title: Amplifier

text: As soon as any connection within the circuit gets longer than perhaps 1% of the wavelength of the highest specified frequency (e.g., at 100 MHz the wavelength is 3 m, so the critical connection length is approx. 3 cm) design properties radically change. For example, a specified length and width of a PCB trace can be used as a selective or impedance-matching entity.


title: Amplifier

text: Above a few hundred MHz, it gets difficult to use discrete elements, especially inductors. In most cases, PCB traces of very closely defined shapes are used instead (stripline techniques).


title: Amplifier

text: The frequency range handled by an amplifier might be specified in terms of bandwidth (normally implying a response that is 3 dB down when the frequency reaches the specified bandwidth), or by specifying a frequency response that is within a certain number of decibels between a lower and an upper frequency (e.g. "20 Hz to 20 kHz plus or minus 1 dB").


title: Amplifier

text: Power amplifier circuits (output stages) are classified as A, B, AB and C for analog designs—and class D and E for switching designs. The power amplifier classes are based on the proportion of each input cycle (conduction angle) during which an amplifying device passes current. The image of the conduction angle derives from amplifying a sinusoidal signal. If the device is always on, the conducting angle is 360°. If it is on for only half of each cycle, the angle is 180°. The angle of flow is closely related to the amplifier power efficiency.


title: Amplifier

text: The practical amplifier circuit shown above could be the basis for a moderate-power audio amplifier. It features a typical (though substantially simplified) design as found in modern amplifiers, with a class-AB push–pull output stage, and uses some overall negative feedback. Bipolar transistors are shown, but this design would also be realizable with FETs or valves.


title: Amplifier

text: The input signal is coupled through capacitor C1 to the base of transistor Q1. The capacitor allows the AC signal to pass, but blocks the DC bias voltage established by resistors R1 and R2 so that any preceding circuit is not affected by it. Q1 and Q2 form a differential amplifier (an amplifier that multiplies the difference between two inputs by some constant), in an arrangement known as a long-tailed pair. This arrangement is used to conveniently allow the use of negative feedback, which is fed from the output to Q2 via R7 and R8.


title: Amplifier

text: The negative feedback into the difference amplifier allows the amplifier to compare the input to the actual output. The amplified signal from Q1 is directly fed to the second stage, Q3, which is a common emitter stage that provides further amplification of the signal and the DC bias for the output stages, Q4 and Q5. R6 provides the load for Q3 (a better design would probably use some form of active load here, such as a constant-current sink). So far, all of the amplifier is operating in class A. The output pair are arranged in class-AB push–pull, also called a complementary pair. They provide the majority of the current amplification (while consuming low quiescent current) and directly drive the load, connected via DC-blocking capacitor C2. The diodes D1 and D2 provide a small amount of constant voltage bias for the output pair, just biasing them into the conducting state so that crossover distortion is minimized. That is, the diodes push the output stage firmly into class-AB mode (assuming that the base-emitter drop of the output transistors is reduced by heat dissipation).


title: Amplifier

text: This design is simple, but a good basis for a practical design because it automatically stabilises its operating point, since feedback internally operates from DC up through the audio range and beyond. Further circuit elements would probably be found in a real design that would roll-off the frequency response above the needed range to prevent the possibility of unwanted oscillation. Also, the use of fixed diode bias as shown here can cause problems if the diodes are not both electrically and thermally matched to the output transistors if the output transistors turn on too much, they can easily overheat and destroy themselves, as the full current from the power supply is not limited at this stage.


title: Amplifier

text: A common solution to help stabilise the output devices is to include some emitter resistors, typically one ohm or so. Calculating the values of the circuit's resistors and capacitors is done based on the components employed and the intended use of the amp.


title: Amplifier

text: Any real amplifier is an imperfect realization of an ideal amplifier. An important limitation of a real amplifier is that the output it generates is ultimately limited by the power available from the power supply. An amplifier saturates and clips the output if the input signal becomes too large for the amplifier to reproduce or exceeds operational limits for the device. The power supply may influence the output, so must be considered in the design. The power output from an amplifier cannot exceed its input power.


title: Amplifier

text: The amplifier circuit has an "open loop" performance. This is described by various parameters (gain, slew rate, output impedance, distortion, bandwidth, signal-to-noise ratio, etc.). Many modern amplifiers use negative feedback techniques to hold the gain at the desired value and reduce distortion. Negative loop feedback has the intended effect of lowering the output impedance and thereby increasing electrical damping of loudspeaker motion at and near the resonance frequency of the speaker.


title: Amplifier

text: When assessing rated amplifier power output, it is useful to consider the applied load, the signal type (e.g., speech or music), required power output duration (i.e., short-time or continuous), and required dynamic range (e.g., recorded or live audio). In high-powered audio applications that require long cables to the load (e.g., cinemas and shopping centres) it may be more efficient to connect to the load at line output voltage, with matching transformers at source and loads. This avoids long runs of heavy speaker cables.


title: Amplifier

text: To prevent instability or overheating requires care to ensure solid state amplifiers are adequately loaded. Most have a rated minimum load impedance.


title: Amplifier

text: All amplifiers generate heat through electrical losses. The amplifier must dissipate this heat via convection or forced air cooling. Heat can damage or reduce electronic component service life. Designers and installers must also consider heating effects on adjacent equipment.


title: Amplifier

text: Different power supply types result in many different methods of bias. Bias is a technique by which active devices are set to operate in a particular region, or by which the DC component of the output signal is set to the midpoint between the maximum voltages available from the power supply. Most amplifiers use several devices at each stage; they are typically matched in specifications except for polarity. Matched inverted polarity devices are called complementary pairs. Class-A amplifiers generally use only one device, unless the power supply is set to provide both positive and negative voltages, in which case a dual device symmetrical design may be used. Class-C amplifiers, by definition, use a single polarity supply.


title: Amplifier

text: Amplifiers often have multiple stages in cascade to increase gain. Each stage of these designs may be a different type of amp to suit the needs of that stage. For instance, the first stage might be a class-A stage, feeding a class-AB push–pull second stage, which then drives a class-G final output stage, taking advantage of the strengths of each type, while minimizing their weaknesses.


title: Supercharger

text: In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement.


title: Supercharger

text: The current categorisation is that a supercharger is a form of forced induction that is mechanically powered (usually by a belt from the engine's crankshaft), as opposed to a turbocharger, which is powered by the kinetic energy of the exhaust gasses. However, up until the mid-20th century, a turbocharger was called a "turbosupercharger" and was considered a type of supercharger.


title: Supercharger

text: The first supercharged engine was built in 1878, with usage in aircraft engines beginning in the 1910s and usage in car engines beginning in the 1920s. In piston engines used by aircraft, supercharging was often used to compensate for the lower air density at high altitudes. Supercharging is less commonly used in the 21st century, as manufacturers have shifted to turbochargers to reduce fuel consumption and/or increase power outputs.


title: Supercharger

text: There are two main families of superchargers defined according to the method of gas transfer: "positive displacement" and "dynamic" superchargers. Positive displacement superchargers deliver an almost constant level of boost pressure increase at all engine speeds (RPM), while dynamic superchargers cause the boost pressure to rise exponentially with RPM (above a certain RPM threshold). Another family of supercharger, albeit rarely used, is the pressure wave supercharger.


title: Supercharger

text: Roots blowers (a positive displacement design) tend to be only 40–50% efficient at high boost levels, compared with 70-85% for dynamic superchargers. Lysholm-style blowers (a rotary-screw design) can be nearly as efficient as dynamic superchargers over a narrow range of load/speed/boost, for which the system must be specifically designed.


title: Supercharger

text: Positive displacement pumps deliver a nearly fixed volume of air per revolution of the compressor (except for leakage, which typically has a reduced effect at higher engine speeds). The most common type of positive-displacement superchargers is the Roots-type supercharger. Other types include the rotary-screw, sliding vane and scroll-type superchargers.


title: Supercharger

text: The rating system for positive-displacement superchargers is usually based on their capacity per revolution. In the case of the Roots blower, the GMC rating pattern is typical. The GMC rating is based on how many two-stroke cylinders - and the size of those cylinders - that it is designed to scavenge, with GMC's model range including 2–71, 3–71, 4–71 and 6–71 blowers. The 6–71 blower, for example, is designed to scavenge six cylinders of each, resulting in an engine with a total displacement of ). However, because 6–71 is the engine's designation rather than that of the blower, the actual displacement of the blower is less; for example, a 6–71 blower pumps per revolution. Other supercharger manufacturers have produced blowers rated up to 16–71.


title: Supercharger

text: Dynamic compressors rely on accelerating the air to high speed and then exchanging that velocity for pressure by diffusing or slowing it down.


title: Supercharger

text: Fuels with a higher octane rating are better able to resist auto ignition and detonation. As a result, the amount of boost supplied by the superchargers could be increased, resulting in an increase in engine output. The development of 100-octane aviation fuel, pioneered in the USA in the 1930s, enabled the use of higher boost pressures to be used on high-performance aviation engines and was used to vastly increase the power output for several speed record airplanes.


title: Supercharger

text: Military use of high-octane fuels began in early 1940 when 100-octane fuel was delivered to the British Royal Air Force fighting in World War II. The German Luftwaffe also had supplies of a similar fuel. Increasing the octane rating became a major focus of aero engine development for the remainder of the war, with later fuels having up to a nominal 150-octane rating. Using such fuels, aero engines like the Rolls-Royce "Merlin 66" and Daimler-Benz "DB 605 DC" produced power outputs of up to .


title: Supercharger

text: One disadvantage of forced induction (i.e. supercharging or turbocharging) is that compressing the intake air increases its temperature. For an internal combustion engine, the temperature of the intake air becomes a limiting factor in engine performance. Extreme temperatures can cause pre-ignition or knocking, which reduces performance and can cause engine damage. The risk of pre-ignition/knocking increases with higher ambient air temperatures and higher boost levels.


title: Supercharger

text: Turbocharged engines use energy from the exhaust gas that would normally be wasted, compared with a supercharged which mechanically draws power from the engine. Therefore turbocharged engines usually produce more power and better fuel economy than supercharged engines. However, turbochargers can cause turbo lag (especially at lower RPM), where the exhaust gas flow is initially insufficient to spin the turbocharger and achieve the desired boost level, thus leading to a delay in the throttle response. For this reason, supercharged engines are common in applications where throttle response is a key concern, such as drag racing and tractor pulling competitions.


title: Supercharger

text: A disadvantage of supercharging is that the engine must withstand the net power output of the engine plus the power to drive the supercharger.


title: Supercharger

text: Turbocharged engines are more prone to heat soak of the intake air (since turbocharging can place the hot exhaust components near the intake air system), although this can be overcome through the use of an intercooler.


title: Supercharger

text: The majority of aircraft engines used during World War II used mechanically driven superchargers because they had some significant manufacturing advantages over turbochargers. However, the benefit to the operational range was given a much higher priority to American aircraft because of a less predictable requirement on the operational range and having to travel far from their home bases. Consequently, turbochargers were mainly employed in American aircraft engines such as the Allison V-1710 and the Pratt & Whitney R-2800, which were comparably heavier when turbocharged, and required additional ducting of expensive high-temperature metal alloys in the gas turbine and a pre-turbine section of the exhaust system. The size of the ducting alone was a serious design consideration. For example, both the F4U Corsair and the P-47 Thunderbolt used the same radial engine, but the large barrel-shaped fuselage of the turbocharged P-47 was needed because of the amount of ducting to and from the turbocharger in the rear of the aircraft. The F4U used a two-stage inter-cooled supercharger with a more compact layout. Nonetheless, turbochargers were useful in high-altitude bombers and some fighter aircraft due to the increased high altitude performance and range.


title: Supercharger

text: Turbocharged piston engines are also subject to many of the same operating restrictions as those of gas turbine engines. Turbocharged engines also require frequent inspections of their turbochargers and exhaust systems to search for possible damage caused by the extreme heat and pressure of the turbochargers. Such damage was a prominent problem in the early models of the American Boeing B-29 Superfortress high-altitude bombers used in the Pacific Theater of Operations during 1944–45.


title: Supercharger

text: Turbocharged piston engines continued to be used in a large number of postwar airplanes, such as the B-50 Superfortress, the KC-97 Stratofreighter, the Boeing 377 Stratocruiser, the Lockheed Constellation, and the C-124 Globemaster II.


title: Supercharger

text: In the 1985 and 1986 World Rally Championships, Lancia ran the Delta S4, which incorporated both a belt-driven supercharger and exhaust-driven turbocharger. The design used a complex series of bypass valves in the induction and exhaust systems as well as an electromagnetic clutch so that, at low engine speeds, a boost was derived from the supercharger. In the middle of the rev range, a boost was derived from both systems, while at the highest revs the system disconnected the drive from the supercharger and isolated the associated ducting. This was done in an attempt to exploit the advantages of each of the charging systems while removing the disadvantages. In turn, this approach brought greater complexity and affected the car's reliability in WRC events, as well as increasing the weight of engine ancillaries in the finished design.


title: Supercharger

text: Twincharged engines have occasionally been used in production cars, such as the 2005-2007 Volkswagen 1.4 litre and the 2017-present Volvo B4204T43/B4204T48 2.0 litre four-cylinder engines.


title: Supercharger

text: In 1849, G. Jones of Birmingham, England began manufacturing a lobe pump compressor to provide ventilation for coal mines. In 1860, the Roots Blower Company (founded by brothers Philander and Francis Marion Roots) in the United States patented the design for an air mover for use in blast furnaces and other industrial applications. This air mover and Birmingham's ventilation compressor both used designs similar to that of the later Roots-type superchargers.


title: Supercharger

text: In March of 1878, German engineer Heinrich Krigar obtained the first patent for a screw-type compressor. The design was a two-lobe rotor assembly with identically-shaped rotors, however the design did not reach production.


title: Supercharger

text: Also in 1878, Scottish engineer Dugald Clerk designed the first supercharger which was used with an engine. This supercharger was used with a two-stroke gas engine. Gottlieb Daimler received a German patent for supercharging an internal combustion engine in 1885. Louis Renault patented a centrifugal supercharger in France in 1902.


title: Supercharger

text: The world's first series-produced cars with superchargers were the 1.6 litre "Mercedes 6/25 hp" and 2.6 litre "Mercedes 10/40 hp", both of which began production in 1923.<ref name="mercedes-benz-classic.com/content"></ref><ref name="benzinsider.com/2008"></ref> They were marketed as "Kompressor" models, a term which was used for various models until 2012.


title: Supercharger

text: Supercharged racing cars from around this time included the 1923 "Fiat 805-405", the 1923 "Miller 122" the 1924 Alfa Romeo P2, the 1924 Grand Prix season car from Sunbeam, the 1925 Delage,<ref name="kolumbus.fi/leif.snellman"></ref> and the 1926 Bugatti Type 35C.


title: Supercharger

text: Amongst the most famous supercharged cars is the Bentley 4½ Litre ("Blower Bentley"), which was introduced in 1929.


title: Supercharger

text: In 1935, the development of screw-type superchargers reached a milestone when Swedish engineer Alf Lysholm patented a design for a rotary-screw compressor with five female and four male rotors.


title: Supercharger

text: In the 21st century, supercharged production car engines have become less common, as manufacturers have shifted to turbocharging to achieve higher fuel economy and power outputs. For example, Mercedes-Benz's engines of the early 2000s (such as the C230K straight-four, C32 AMG V6, and CL55 AMG V8 engines) were replaced around 2010 by turbocharged engines in models such as the "C250" and "CL S65 AMG" models. However, there are exceptions, such as the Audi 3.0 TFSI supercharged V6 (introduced in 2009) and the Jaguar AJ-V8 supercharged V8 (upgraded to the "Gen III" version in 2009).


title: Supercharger

text: In the 1930s, two-speed drives were developed for superchargers for aero engines providing more flexible aircraft operation. The arrangement also entailed more complexity of manufacturing and maintenance. The gears connected the supercharger to the engine using a system of hydraulic clutches, which were initially manually engaged or disengaged by the pilot with a control in the cockpit. At low altitudes, the low-speed gear would be used, to prevent excessive boost levels. At higher altitudes, the supercharger could be switched to a higher gear to compensate for the reduced intake air density. In the Battle of Britain the Spitfire and Hurricane planes powered by the Rolls-Royce Merlin engine were equipped largely with single-stage and single-speed superchargers.


title: Supercharger

text: In 1942, two-speed two-stage supercharging with aftercooling was applied to the Rolls Royce Merlin 61 aero engine. The improved performance allowed the aircraft they powered to maintain a crucial advantage over the German aircraft they opposed throughout World War II, despite the German engines being significantly larger in displacement. Two-stage superchargers were also always two-speed. After the air was compressed in the "low-pressure stage", the air flowed through a heat exchanger ("intercooler") where it was cooled before being compressed again by the "high-pressure stage" and then possibly also "aftercooled" in another heat exchanger.


title: Supercharger

text: Due to the reduced air density at higher altitudes, supercharging and turbocharging have often been used in aircraft engines. For example, the air density at is of that at sea level, resulting in as much fuel being able to be burnt in a naturally aspirated engine, therefore the power output would be greatly reduced. A supercharger/turbocharger can be thought of either as artificially increasing the density of the air by compressing it or as forcing more air than normal into the cylinder every time the piston moves down on the intake stroke.


title: Supercharger

text: Since a supercharger is usually designed to produce a given amount of boost at high altitudes (where the air density is lower), the supercharger is often oversized for low altitude. To prevent excessive boost levels, it is important to monitor the intake manifold pressure at low altitude. As the aircraft climbs and the air density drops, the throttle can be progressively opened to obtain the maximum safe power level for a given altitude. The altitude at which the throttle reaches full open and the engine is still producing full rated power is known as the "critical altitude". Above the critical altitude, engine power output will reduce as the supercharger can no longer fully compensate for the decreasing air density.


title: Supercharger

text: Another issue encountered at low altitudes (such as at ground level) is that the intake air is warmer than at high altitude. Warmer air reduces the threshold at which engine knocking can occur, especially in supercharged or turbocharged engines. Methods to cool the intake air at ground level include intercoolers/aftercoolers, anti-detonant injection, two-speed superchargers and two-stage superchargers.


title: Supercharger

text: In supercharged engines which use a carburetor, a partially-open throttle reduces the air pressure within the carburettor. In cold conditions, this low pressure air can cause ice to form at the throttle plate. Significant quantities of ice can cause engine failure, even with the engine operating at full rated power.


title: Oldsmobile

text: Oldsmobile or formally the Oldsmobile Division of General Motors was a brand of American automobiles, produced for most of its existence by General Motors. Originally established as "Olds Motor Vehicle Company" by Ransom E. Olds in 1897, it produced over 35 million vehicles, including at least 14 million built at its Lansing, Michigan factory alone. During its time as a division of General Motors, Oldsmobile slotted into the middle of GM's five (passenger car) divisions (above Chevrolet and Pontiac, but below Buick and Cadillac), and was noted for several groundbreaking technologies and designs.


title: Oldsmobile

text: Oldsmobile's sales peaked at over one million annually from 1983 to 1986, but by the 1990s the division faced growing competition from premium import brands, and sales steadily declined. When it shut down in 2004, Oldsmobile was the oldest surviving American automobile marque, and one of the oldest in the world, after Mercedes-Benz, Peugeot, Renault, Fiat, Opel, Autocar and Tatra (initially Nesselsdorfer Wagenbau co.).


title: Oldsmobile

text: Oldsmobiles were first manufactured by the Olds Motor Vehicle Co. in Lansing, Michigan, a company founded by Ransom E. Olds in 1897. In 1901 (the same year that Horace and John Dodge won a contract to produce transmissions for the Oldsmobile company), the company produced 635 cars, making it the first high-volume gasoline-powered automobile manufacturer. (Electric car manufacturers such as Columbia Electric and steam-powered car manufacturers such as Locomobile had higher volumes a few years earlier.) Oldsmobile became the top-selling car company in the United States for a few years around 1903–1904. Ransom Olds left the company in 1904 because of a dispute with sales manager Frederick Smith, who was questioning production techniques and wanted Mr. Olds to certify that each car that left the plant was free from defects. Mr. Smith then set up an experimental engineering shop without Mr. Olds' knowledge or consent, causing Mr. Olds to leave in 1904 and formed the REO Motor Car Company. This was a similar situation Henry Ford encountered when he was forced out of the company he founded, the Henry Ford Company and started the Ford Motor Company in 1903. After merging with Diamond T in 1967, Diamond Reo Trucks also lasted into the 21st century, folding in 2013.


title: Oldsmobile

text: The 1902 to 1907 Oldsmobile Model R "Curved Dash" was the first mass-produced car, made from the first automotive assembly line, an invention which is often incorrectly credited to Henry Ford and the Ford Motor Company. Ford was the first to manufacture cars on a "moving" assembly line, while Olds used a stationary assembly line, meaning that the assembled vehicle remained in one place and workers would move from one car to the next and perform one assigned task. This differed from hand-made vehicles in the past where various workers would work on one car until it was completed and was labor- and time-intensive. After Olds merged Olds Motor Vehicle Co. with the Olds Gas Engine Works in 1899, it was renamed "Olds Motor Works" and moved to a new plant in Detroit, located at the corner of East Jefferson Avenue and MacArthur Bridge. By March 1901, the company had a whole line of models ready for mass production. However, a mistake by a worker caused the factory to catch fire, and it burned to the ground, with all of the prototypes destroyed. The only car that survived the fire was a Curved Dash prototype, which was wheeled out of the factory by two workers while escaping the fire. While the factory was being rebuilt from insurance, many subcontractors were used to keep production going, to include Henry M. Leland for engines and the Dodge Brothers. Olds was a strong competitor to other independent companies Buick and Cadillac before they became divisions of General Motors between 1908 and 1909. Later after Mr. Olds left the company, Oldsmobile production was moved to Lansing.


title: Oldsmobile

text: Officially, the cars were called "Olds automobiles," but were colloquially referred to as "Oldsmobiles." It was this moniker, as applied especially to the Curved Dash Olds, that was popularized in the lyrics and title of the 1905 hit song "In My Merry Oldsmobile". The last Oldsmobile Curved Dash was made in 1907. General Motors purchased the company on November 12, 1908. When GM assumed operations, platform sharing began with Buick products and Oldsmobile shared platforms were identified with the prefix "Series" followed by a number, while models developed by pre-GM engineers were identified with the prefix "Model" followed by a letter. Early on, Oldsmobile was a competitor to Hudson as some former engineers of Oldsmobile took positions with Hudson.


title: Oldsmobile

text: The 1910 Limited Touring Series 23 was an early, ambitious, high point for the company. Riding atop 42-inch (1067 mm) wheels, and equipped with factory "white" tires, the Limited was the prestige model in Oldsmobile's two model lineup, with the smaller Oldsmobile Autocrat Series 32 having 36-inch wheels.


title: Oldsmobile

text: The Limited retailed for US$4,600, ($ in dollars ) an amount greater than the price of a new basic three-bedroom house. Buyers received goatskin upholstery, a 60 hp (45 kW) 707 CID (11.6 L) T-head straight-six engine, Bosch Magneto starter, running boards and room for five. Options included a speedometer, clock, and a full glass windshield. A limousine version was priced at $5,800 ($ in dollars ). While Oldsmobile only sold 725 Limiteds in its three years of production, the car is best remembered for winning a race against the famed 20th Century Limited train, an event immortalized in the painting "Setting the Pace" by William Hardner Foster.


title: Oldsmobile

text: The Limited was at the time considered technologically advanced and cutting edge, if on the expensive side, but it established the division's reputation for innovation. The Oldsmobile Series 40 was offered in 1912 and was considerably more affordable and smaller, and later the Oldsmobile Light Eight in 1916, Oldsmobile offered a Cadillac-sourced flathead V8 engine until 1923, while Buick remained with their division exclusive overhead valve straight-six engine until 1930.


title: Oldsmobile

text: Beginning in 1910, bodywork was supplied by Fisher Body, a longstanding tradition that led to the company being eventually merged into GM in later years.


title: Oldsmobile

text: In 1926, the Oldsmobile Six came in five body styles, and ushered in a new GM bodystyle platform called the "GM B platform", shared with Buick products.


title: Oldsmobile

text: In 1929, as part of General Motors' companion make program, Oldsmobile introduced the higher standard Viking brand, marketed through the Oldsmobile dealer network. Viking was already discontinued at the end of the 1930 model year although an additional 353 cars were marketed as 1931 models.


title: Oldsmobile

text: In the 1930s, Oldsmobile produced two body styles of automobile, the Series F (straight-6 cylinder) and the longer Series L (straight-8 cylinder). In 1933 The "Oldsmobile Program" appeared on CBS radio for two years which was a new advertising approach to sell products and services.


title: Oldsmobile

text: In 1937, Oldsmobile was a pioneer in introducing a four-speed semi-automatic transmission called the "Automatic Safety Transmission", although this accessory was actually built by Buick, which would offer it in its own cars in 1938. This transmission features a conventional clutch pedal, which the driver presses before selecting either "low" or "high" range. In "low," the car shifts between first and second gears. In "high," the car shifts among first, third and fourth gears.


title: Oldsmobile

text: For the 1940 model, Oldsmobile was the first auto manufacturer to offer a fully automatic transmission, called the "Hydramatic", which features four forward speeds. It has a gas pedal and a brake—no clutch pedal. The gear selector is on the steering column.


title: Oldsmobile

text: Starting in 1941 and continuing through 1999, Oldsmobile used a two-digit model designation. As originally implemented, the first digit signifies the body size while the second represents the number of cylinders. Body sizes were 6, 7, 8, and 9, and straight six- and straight eight-cylinder engines were offered. Thus, Oldsmobiles were named "66" through "98".


title: Oldsmobile

text: Until January 1, 1942, the Division was still known by the still official name of Olds Motor Works, when it was changed to the collective name the cars were known as, "Oldsmobiles". Thus, the division was officially christened the Oldsmobile Division of General Motors.


title: Oldsmobile

text: The last pre-war Oldsmobile rolled off the assembly line on February 5, 1942. During World War II, Oldsmobile produced numerous kinds of material for the war effort, including large-caliber guns and shells. Production resumed on October 15, 1945, with a warmed-over 1942 model serving as the offering for 1946.


title: Oldsmobile

text: Oldsmobile once again was a pioneer when, for the 1949 model, the Rocket engine was introduced, which used an overhead valve V8 design rather than the flathead "straight-eight" design which prevailed at the time. The overhead valve was originally exclusive to Buick as they invented the technology and offered it on all of their products. This engine produced far more power than the other engines that were popular during that era, and found favor with hot-rodders and stock car racers. The basic design, with a few minor changes, endured until Oldsmobile redesigned its V8 engines in the mid-1960s.


title: Oldsmobile

text: Oldsmobile entered the 1950s following a divisional image campaign centered on its 'Rocket' engines and the Space Race, and its cars' appearance followed suit. Oldsmobile's Rocket V8 engine was the leader in performance; its cars were generally considered the fastest on the market; and by the mid-1950s their styling was among the first to offer a wide, "open maw" grille, suggestive of fighter jet propulsion. From 1948 to 1957, Oldsmobile adopted a ringed-globe emblem depicting North America to stress what marketers felt was its universal appeal. Starting in 1958, the grille logo changed again to reflect the rocket image, that was used throughout the late 1950s, the make used twin jet pod-styled taillights as a nod to its "Rocket" theme. Oldsmobile was among the first of General Motors' divisions to receive a true hardtop in 1950 called the "Holiday coupe" (Buick's version was called the "Riviera", and Cadillac's was called the "Coupe De Ville"), and it was also among the first divisions (along with Buick and Cadillac) to receive a wraparound windshield, a trend that eventually all American makes would share at sometime between 1953 and 1964. New for 1954 on 98 coupes and convertibles (Starfire) would be front and rear "sweep cut" fender styling, which would not show up on a Chevrolet until 1956 and not until 1957 on a Pontiac. 1953 models changed to a 12 volt electrical system that made starting easier.


title: Oldsmobile

text: In the 1950s the nomenclature changed again, and trim levels also received names that were then mated with the model numbers. This resulted in the Oldsmobile 88 emerging as base Dynamic 88 and the highline Super 88. Other full-size model names included the "Holiday" used on hardtops, and "Fiesta" used on its station wagons. When the 88 was retired in 1999 (with a Fiftieth Anniversary Edition), its length of service was the longest model name used on American cars after the Chrysler New Yorker. Mid-1955 also saw the introduction of the four-door Holiday pillarless hardtop, the industry's first (along with Buick).


title: Oldsmobile

text: General Motors' styling as a whole lost its frontrunner status in 1957 when Chrysler introduced Virgil Exner's "forward look" designs. When compared side to side, Oldsmobile looked dated next to its price-point competitors DeSoto and Mercury. Compounding the problem for Oldsmobile and Buick was a styling mistake which GM called the "StratoRoof", which was reminiscent of the "greenhouse" canopy used on the Convair B-36 Peacemaker high altitude bomber. Both makes had models which contained the heavily framed rear window, but Detroit had been working with large curved backlights for almost a decade. Consumers disliked the roof and its blind spots, forcing GM to rush a redesign into production on some of its models. Oldsmobile's only off year in the 1950s was 1958. The nation was beginning to feel the results of its first significant post-war recession, and US automobile sales were down for the model year. Oldsmobile, Buick and Cadillac received a heavy-handed makeover of the 1957 GM designs. The Oldsmobile that emerged in 1958 bore little resemblance to the design of its forerunners; instead the car emerged as a large, over-decorated "chromemobile" which many felt had overly ostentatious styling.


title: Oldsmobile

text: Up front, all 1958 Oldsmobile's received one of General Motors' heavily styled front facias and quad-headlights. Streaking back from the edge of the headlights was a broad belt consisting of two strips of chrome on regular 88s, three strips on Super 88s, and three strips (top and bottom thin, inside thick) on 98s that ended in a point at mid-body. The bottom of the rear fender featured a thick stamping of a half tube that pointed forward, atop which was a chrome assembly of four horizontal chrome speed-lines that terminated into a vertical bar. The tail of the car featured massive vertical chrome taillight housings. Two chrome stars were fitted to the trunklid.


title: Oldsmobile

text: Ford styling consultant Alex Tremulis (designer of the 1948 Tucker sedan) mocked the 1958 Oldsmobile by drawing cartoons of the car, and placing musical notes in the rear trim assembly. Another Detroit stylist employed by Ford bought a used 1958 Oldsmobile in the early 1960s, driving it daily to work. He detached and rearranged the "Oldsmobile" lettering above the grille to spell out "slobmodel" as a reminder to himself and co-workers of what "bad" auto design meant to their business.


title: Oldsmobile

text: In 1959, Oldsmobile models were completely redesigned with a rocket motif from front to rear, as the top of the front fenders had a chrome rocket, while the body-length fins were shaped as rocket exhausts which culminated in a fin-top taillight (concave on the 98 models while convex on the 88 models). The 1959 models also offered several roof treatments, such as the pillared sedan with a fastback rear window and the Holiday SportSedan, which was a flat-roofed pillarless hardtop with wraparound front and rear glass. The 1959 models were marketed as "the linear look", and also featured a bar-graph speedometer which showed a green indicator through , then changed to orange until , then was red above that until the highest speed read by the speedometer, . Power windows were available on the 98 models, as were two-speed electric windshield wipers with electrically powered windshield washers. The 88 still relied on vacuum-operated windshield wipers without a washer feature. 1959 Oldsmobiles were offered with "Autronic Eye" (a dashboard-mounted automatic headlight dimmer) as well as factory-installed air conditioning and power-operated front bench seat as available options. The 1959 body style was continued through the 1960 model year, but the fins were toned down for 1960 and the taillights were moved to the bottom of the fenders.


title: Oldsmobile

text: Notable achievements for Oldsmobile in the 1960s included the introduction of the first turbocharged engine and a factory water injection system in 1962 (the Turbo Jetfire), the first modern front-wheel drive car produced in the United States (the 1966 Toronado), the Vista Cruiser station wagon (noted for its roof glass), and the upscale 442 muscle car. Olds briefly used the names "Jetstar 88" (1964–1966) and Delmont 88 (1967–1968) on its least expensive full-size models in the 1960s. In 1968 the split grille appearance was introduced and remained a traditional feature until production ended in 2004.


title: Oldsmobile

text: The 1970s and 1980s were good years for the Oldsmobile division; sales soared (reaching an all-time high of 1,066,122 in 1985) based on popular designs, positive reviews from critics, and perceived quality and reliability, with the Cutlass series becoming North America's top-selling car by 1976. By this time, Olds had displaced Pontiac and Plymouth as the third best-selling brand in the U.S. behind Chevrolet and Ford. In the late 1970s and again in the mid-1980s, model-year production topped one million units, something only Chevrolet and Ford had achieved.


title: Oldsmobile

text: The very popularity of Oldsmobile's cars created a problem for the division in the late 1970s, however. At that time, each General Motors division produced its own V8 engines, and in 1977, Oldsmobile, Chevrolet, Pontiac, and Buick each produced a unique 350-cubic-inch displacement V8. It was during the 1977 model year that demand exceeded production capacity for the Oldsmobile V8 and as a result, Oldsmobile began equipping most full-size Delta 88 models (those with Federal emissions specifications) with the Chevrolet 350 engine instead. Although it was widely debated whether there was a difference in quality or performance between the two engines, there was no question that the engines were different from one another. Many customers were loyal Oldsmobile buyers who specifically wanted the Rocket V8, and did not discover that their vehicle had the Chevrolet engine until they performed maintenance and discovered that purchased parts did not fit. This became a public relations nightmare for GM.


title: Oldsmobile

text: Following this debacle, disclaimers stating that "Oldsmobiles are equipped with engines produced by various GM divisions" were tacked onto advertisements and sales literature; all other GM divisions followed suit. In addition, GM quickly stopped associating engines with particular divisions and to this day, all GM engines are produced by "GM Powertrain" (GMPT) and are called GM "Corporate" engines instead of GM "Division" engines. Although it was the popularity of the Oldsmobile division vehicles that prompted this change, declining sales of V8 engines would have made this change inevitable as all but the Chevrolet version of the 350-cubic-inch engine were eventually discontinued.


title: Oldsmobile

text: Oldsmobile also introduced a 5.7L (350 cu-in) V8 diesel engine option on its Custom Cruiser, Delta 88 and 98 models in 1978; and a smaller 4.3L (260 cu-in) displacement V8 diesel on the 1979 Cutlass Salon and Cutlass Supreme/Cutlass Calais models. These were largely based on corresponding gasoline engines but with heavier duty cast blocks, redesigned heads and fast glow plugs; and on the 5.7L, oversized cranks, main bearings and wrist pins. There were several problems with these engines, including water and corrosion in the injectors (no water separator in the fuel line); paraffin clogging of fuel lines and filters in cold weather; reduced lubrication in the heads due to undersized oil galleys; head bolt failures; and the use of aluminum rockers and stanchions in the 4.3L V8 engines. While the 5.7L was also offered on various Buick, Cadillac, Chevrolet, GMC, and Pontiac models, it was eventually discontinued by all divisions in 1985. V6 diesels of 4.3L displacement were also offered between 1982 and 1985. In 1988 the then all-new 1988 Oldsmobile Cutlass Supreme Pace car was the 1st production car with heads up display.


title: Oldsmobile

text: After the tremendous success of the 1970s and 1980s, things changed quickly for Oldsmobile, and by the early 1990s the brand had lost its place in the market (as annual sales had fallen from a record high of 1,066,122 in 1985 to just 402,936 in 1993), squeezed between other GM divisions, and with competition from new upscale import makes Acura, Infiniti and Lexus. GM continued to use Oldsmobile sporadically to showcase futuristic designs and as a "guinea pig" for testing new technology, with Oldsmobile offering the Toronado Trofeo, which included a visual instrument system with a calendar, datebook, climate controls and several prototypes built in conjunction with Avis with an early satellite-based navigation system. For 1995, Oldsmobile introduced the Aurora, which would be the inspiration for the design of its cars from the mid-1990s onward. The introduction of the Aurora marked as General Motors' catalyst to reposition Oldsmobile as an upscale import fighter. Accordingly, Oldsmobile received a new logo based on the familiar "rocket" theme. Also in 1995 Oldsmobile introduced the first satellite navigation system available in the United States, the Guidestar on the 1995 Oldsmobile 88. Nearly all the existing model names were gradually phased out: the Cutlass Calais in 1991, the Toronado and Custom Cruiser in 1992, the Ninety-Eight and Ciera (formerly Cutlass Ciera) in 1996, Cutlass Supreme in 1997, and finally the Eighty-Eight and Cutlass (which had only been around since '97) in 1999. They were replaced with newer, more modern models with designs inspired by the Aurora.


title: Oldsmobile

text: In spite of Oldsmobile's critical successes since the mid-1990s, a reported shortfall in sales and overall profitability prompted General Motors to announce in December 2000 its plans to shut down the Oldsmobile organization. That announcement was officially revealed two days after Oldsmobile distributed the Bravada SUV – which became another critical hit for the division but turned out to be the final new model for the Oldsmobile brand.


title: Oldsmobile

text: The last 500 Aleros, Auroras, Bravadas, Silhouettes and Intrigues produced received special Oldsmobile heritage emblems and markings which signified 'Final 500'. All featured a unique Dark Cherry Metallic paint scheme. Auroras and Intrigues would be accompanied by special Final 500 literature. However, only the Intrigue, Aurora, Bravada, and Alero had all Final 500 models built; the Silhouette only had 360 built as a result of the plant running out of out of production capacity due to fleet order obligations for minivans on the same assembly line. The Oldsmobile division's last completed production car was an Alero GLS 4-door sedan, which was signed by all of the Olds assembly line workers. It was on display at the R. E. Olds Transportation Museum located in Lansing, Michigan until GM's bankruptcy, when it retook possession of the car. It was then located at the GM Heritage Center in Sterling Heights, Michigan. In December 2017, the car headed to New York where it was auctioned off at a dealer-only auction for $42,000 to a Florida dealer. Also sold at the auction were a 1999 Cutlass and a 1999 Ciera.


title: Oldsmobile

text: During the 107 years of Oldsmobile's existence, it was known for being a guinea pig for new technologies and firsts.


title: Oldsmobile

text: The 200,000 square-foot Oldsmobile Administration Building, also known as Building 70, was completed in 1966 to accommodate the company's major administration departments. Located at 920 Townsend Avenue, at what is currently the GM Lansing Grand River Assembly plant, the project was constructed by Michigan contractor Utley-James, with architectural design contracted by GMAC.


title: Oldsmobile

text: The headquarters accommodated about 900 employees in a Modern design with exterior marble and curtain walls reminiscent of the General Motors Technical Center. Approach walkways integrated snow melting units, and the design incorporated interior and exterior artwork. The building has two prominent interconnected towers in the northeast corner: a six-level north wing and a four-level south wing. The building's two-story lobby featured a sunken visitor waiting area, a place to display a current Oldsmobile, and a reception area, 'floating' within a water pool.


title: Oldsmobile

text: Oldsmobile commissioned two prominent sculptures by noted sculptor Samuel Cashwan, who had previously served on the General Motors Styling Staff. The exterior Cashwan sculpture, titled "Open Cage", previously located outside the Admin Building's primary entrance, was donated in 2006, to be placed at the entrance to the R.E. Olds Transportation Museum. The east wall of the penthouse featured the brand's name, spaced out letter by letter — signage which was removed in 2006 and subsequently also gifted to the Lansing R.E. Olds Transportation Museum. By 1996, the company's remaining employees relocated to Detroit's Renaissance Center.


title: Oldsmobile

text: In Canada the range was limited, with the Oldsmobile Silhouette and Oldsmobile Bravada being unavailable to Canadian consumers until much later in their production life.


title: Oldsmobile

text: For the European market, the Oldsmobile Silhouette was sold between 1994 and 1997 as the Pontiac Trans Sport by replacing the Oldsmobile badging with Pontiac badging, along with Pontiac wheels. Sales in Europe were good for an American import, but did not represent enough volume to make a distinct model economically feasible for the European market. Its successors were both the Chevrolet Trans Sport (Second generation Pontiac Trans Sport rebadged as a Chevrolet) (LWB), and the Opel / Vauxhall Sintra (SWB).


title: Oldsmobile

text: The Oldsmobile Alero was sold in select countries in Europe (and Israel) between 1999 and 2001 as the Chevrolet Alero, and was only available as a 4-door sedan. The car still featured its Oldsmobile badges even though sold under the Chevrolet brand, but since most European consumers would not recognize the badging, Chevrolet badges were added to the grille and rear fascia for the 2000 model year. The Alero featured Chevrolet emblems throughout its entire run in Israel. The Alero was replaced in Europe and Israel by the GM Daewoo-sourced Chevrolet Evanda / Epica.