Canterbury Tales :: English Literature Essays

Canterbury Tales There is a great deal of useful information to be found on the Internet but sorting through it can often be a hassle. There are some sites that are useful and give a great deal of helpful information but there are also many sites that just don't meet up to those standards. Since anyone can put information on the web, it is often hard to tell a good site from a bad one. Today, I am going to go through a few sites relating to Geoffrey Chaucer and his book The Canterbury Tales and give examples of good and bad sites relating to them. One fantastic site that is on the web is The Litrix Reading Room at http://www.litrix.com. This site, which is edited by Sam Jones, gives free electronic distribution of books for use by readers. It gives a list of authors and the books that they have from them. This site has a great number of books and some of the choices are American, Horror, Misfits, Mr. Holmes, Mystery, Sci-fi and Westerns. This site is very helpful in the reading of The Canterbury Tales because it has an updated, translated version of the book that makes it easier to understand and follow the story line. I would recommend litrix.com greatly. One very good site, which relates to Geoffrey Chaucer is http://www.luminarium.org/medlit/chaucer.html. This site is large in depth with many features that will keep any Chaucer fan busy for hours or help students find whatever they may need. Some of the features include: different quotes from Chaucer, a paragraph summary of his life, links to many of his works, audio excerpts from The Canterbury Tales, discussion groups and links to other Chaucer pages. This site was created by Anniina Jokinen and it is clear that she did a very good job. Another fantastic site that relates to Chaucer is http://www.media.wright.edu/studorgs/english20403/chaucer.html. This site has all the links that a person may ever need for Chaucer. Some of the many links that are offered on this site is his biography, Chaucerian language, online reports, and online texts of The Canterbury Tales and medieval sites. Each main link has a few choices beneath it so a person can pick and choose between different sites and writing styles, which is always helpful. Getting different perspectives on different topics relating to Chaucer can only help a person in receiving a better grade and better understanding the material.

?The Rise and Fall of Jim Crow? Essay -- essays research papers

In 1863 Jim Crow was performing black face in major production halls. Jim Crow became a simble of racial discrimation. The erra of Jim Crow had begon at this time. This erra was a time were Jim Crow pushed for blacks have there rights taken from them. During the Jim Crow erra a lot of resterants and bathrooms had signs hanging outside that said coloreds only. Many blacks were fighting to start their commintuies because they felt this was the only way they would have rights.   Ã‚  Ã‚  Ã‚  Ã‚  In 1919 the Klu Kluc Klan ( KKK) became a national power. The Klan was major powerhouse behind Jim Crow. Blacks were not just going to stand by and let the Klan have control over them, so b;acks used the power of the press and the courts to fight back against the klan.   Ã‚  Ã‚  Ã‚  Ã‚  Then the video placed itself back to when Lincoln was presdent of the united states. The narrator talked about how Lincoln did not want the war to be about freeing slaves but , for the war to be about saving the union. During this times the balcks thought that linciln was fighting for them and all they wanted was to have rights. These rights consisted of land , education, ablity to vote ,, but mosting importantly was alnd they believe if theey owned land they were free. In South Carolina blacks had built their own schools, churches and communitys , on the land that they were given during the war. When Andrew Jackson was eleceted into office he did not like the idea fro blacks have their own land. So Andrew Jackson orderd Oliver O Howard a Christian general to remove the black people off the land they had made their homes. Oliver Howard called ammeting at the town hall and some were around 2,000 people attended.   Ã‚  Ã‚  Ã‚  Ã‚  In 1866 Congress passed the 14th and 15th amendments because the south was not looking out for the better intreates of the blacks. At this time reconstruction had began. Around the time reconstruction had began , most black people felt that they did not have to work in the fields or work at hard labor jobs. So they started electing other black man into office so that they could have rights and voice in the government. Also these officals helped with getting schools and education for the black population.   Ã‚  Ã‚  Ã‚  Ã‚  At this time the KKK wanted all of the ex-slaves to fall back into place were they belonged... ...et them run it!† Montgumery wanted a safe place for blacks to live and grow as people. Mound Bayou was very proprose. When Missippi wanted to put in place the Jim Crow laws , Iza Montgumery was delegated to vote against the idea. But Iza voted for the a law against uneducation blacks would not be able to vote. Many blacks acrossed the nation felt this was tresion. Montgumery said that blacks had already lost. Booker T. Washington was mad like Fredrick Douglas. Booker was able to talk to talk to anyone. Booker sureached ideas for a white and black comprmisse. September 25th was calimed Negero day. Booker want to speak and people complained that there was a â€Å"nigger† giving a speech . Almost as if they felt he was unable to speak because he was black. Booker said to the white people we can be as seprate as two fingers but as close as the hand. That speech caused massive confusion for the blacks in the south. Although the white people at the rally were very happy an d impressed by the way Booker talked. To blacks this idea was called the Atlanta Comprimse. Dispite any Advances by blacks they were all surpressed because Jim Crow had complete control over the power of the United States.

Being Charlie Kaufman: A Glimpse into the Mind of a Genius :: Essays Papers

Being Charlie Kaufman: A Glimpse into the Mind of a Genius Movies suck these days. All Hollywood seems to care about anymore is making profitable movies, not thinking twice about what the movie might actually be about. Whether it’s another special effects-ridden clunker, a giddy romantic comedy, or another lame-plotted action flick, they just don’t seem to get it. Although a small handful of films over a year’s time are occasionally worth seeing, for the most part it’s all about making money and not about the true art that filmmaking can be. Charlie Kaufman is exactly the kind of anomaly that the film industry needs. Kaufman was born in November 1958 in Massapequa, Long Island and spent his childhood there. Later his family moved to West Hartford, Connecticut, where he went to high school. After graduating, he attended Boston University for a short time, but soon transferred to New York University to study filmmaking. Kaufman got his start in writing for television for sitcoms such as Ned and Stacey and The Dana Carvey Show (Couzens). After his work with sitcoms, however, he began writing some of the oddest scripts that have ever been conceived. It was just over four years ago when Kaufman presented his very first film, Being John Malkovich, which was nominated for both Oscar and Golden Globe awards, as well as winning many others, such as the Independent Spirit Award for Best First Screenplay and Best Screenplay from the National Society of Film Critics. That is not something every screenwriter is able to do with their first script. His fortune of being nominated came again with his third film, the genre-bending Adaptation, which was a fictional movie about him working on writing the screenplay for a movie adaptation of a book that was based on a true story. His work on this won him the Golden Satellite Award for Best Adapted Screenplay. His latest work, Eternal Sunshine of the Spotless Mind, is being hailed as â€Å"remarkable† with â€Å"groundbreaking performances,† which gives it a very likely chance of being nominated for awards (Travers, 2004). Although his reputation is already respectable, Kaufman didn’t easily get to where he is now. His struggles of becoming a film screenwriter were not without boundaries, but every time he tripped, he got back up and kept going. Being Charlie Kaufman: A Glimpse into the Mind of a Genius :: Essays Papers Being Charlie Kaufman: A Glimpse into the Mind of a Genius Movies suck these days. All Hollywood seems to care about anymore is making profitable movies, not thinking twice about what the movie might actually be about. Whether it’s another special effects-ridden clunker, a giddy romantic comedy, or another lame-plotted action flick, they just don’t seem to get it. Although a small handful of films over a year’s time are occasionally worth seeing, for the most part it’s all about making money and not about the true art that filmmaking can be. Charlie Kaufman is exactly the kind of anomaly that the film industry needs. Kaufman was born in November 1958 in Massapequa, Long Island and spent his childhood there. Later his family moved to West Hartford, Connecticut, where he went to high school. After graduating, he attended Boston University for a short time, but soon transferred to New York University to study filmmaking. Kaufman got his start in writing for television for sitcoms such as Ned and Stacey and The Dana Carvey Show (Couzens). After his work with sitcoms, however, he began writing some of the oddest scripts that have ever been conceived. It was just over four years ago when Kaufman presented his very first film, Being John Malkovich, which was nominated for both Oscar and Golden Globe awards, as well as winning many others, such as the Independent Spirit Award for Best First Screenplay and Best Screenplay from the National Society of Film Critics. That is not something every screenwriter is able to do with their first script. His fortune of being nominated came again with his third film, the genre-bending Adaptation, which was a fictional movie about him working on writing the screenplay for a movie adaptation of a book that was based on a true story. His work on this won him the Golden Satellite Award for Best Adapted Screenplay. His latest work, Eternal Sunshine of the Spotless Mind, is being hailed as â€Å"remarkable† with â€Å"groundbreaking performances,† which gives it a very likely chance of being nominated for awards (Travers, 2004). Although his reputation is already respectable, Kaufman didn’t easily get to where he is now. His struggles of becoming a film screenwriter were not without boundaries, but every time he tripped, he got back up and kept going.

Media Violence Essay

Television has been considered as part of entertainment of the society. Mass media has been recognized as the giver and provider of the information needed by the public. These two terms have too many influences and greatly affects the lives of the people in the society which make them important elements in this post modern world. From gaining knowledge to entertainment, media has been having the reputation of providing all the information needed by the public. However, the society also points out the mass media as the greatest influence of aggressive behavior of the viewers. Through the movies and television shows that are being released by the media, people learn to conform and adopt the attitudes that are portrayed by the characters. The constant changing society has challenge the culture and values of the people around the world. The popular culture has been very influential making the society conform to the new trends. However, there are some factors in the society that are not changing regardless of the transparency of its effects. In other words, these are the aspects that affect the lives of the people negatively but still considered as adequate because of the acceptance of the mainstream. Media violence is one of the negative elements of the society but still existing despite the evident effects to the people. The Viewers and the Media Violence The behavior of the person shows the kind of television program he or she watches (Science Daily). Apparently, media violence does not affect only those who already understand the language and actions of a certain movie or television show. In fact, even the toddlers are being affected by these aggressive behaviors on screen. The people learn based on what they could see in their environment. Undeniably, mass media is one of the most influential factors that is present in this post modern world. The values that people adapt from their surroundings help in developing their personalities as they grow older. Since media has been the easiest tool in gaining information, it has also become an instrument to learn and adapt the culture of the society. The children that are just starting to learn in the society is being trained and influenced by the behaviors that are being portrayed in movies and television programs. Everyday, a home is being penetrated not only by thousands of advertisers that persuade every member of the family to buy a certain product. In fact, the television serves as the bridge of the people to the fictional world that are perfectly created by the mass media. Thousands of scenes from television shows and advertisements are being portrayed and most of them are adopted influencing the mind and personality of an individual. Countless murders and other acts of violence are shown making the audience feel the danger present outside their homes. The martial arts battle, shootings, knifings, fistfights, and exploding cars are just few of the scenes that can be watched on movies or television shows. These acts of violence are usually done by the heroes and villains who often serve as the role models for the young adults in the society (Freedman 4). The aggressive behaviors that the children often see on screen are committed by the live actors or even animated figures that appear in the best movies as well as the worst. On the other hand, the existence of violence in the society has not created by the media themselves. In fact violence has been in the society even before television was invented, movie houses were constructed, and video games were released. Aggression is a nature of man and it has been present even before the technology enter the scene. The public has been blaming the media for the aggression that their shows cause to the people especially to children; however, the media has been firm on telling that their aggressive shows represent the violence of the society. This issue has been at the heart of debate in the society. The presence of media relies on the elements of the society while the society relies on the information that are being offered by the mass media. Effects of Media Violence As the child becomes older, he or she is being accustomed with the information available in his or her surroundings. The internet, television shows, video games, and advertising are the sources of information of children nowadays (Wintour). The presence of media has undeniably influenced the young adults as they grow up to be mature individuals. The aggressive behaviors that they can see on television, movies, or even video games are being adapted and accepted to their own construction of reality. The child learns to hit his playmate when he gets mad, throw things when he is irritated, and shout when somebody did not pay attention to him. These are all examples of aggressive behaviors which may appear to be simple and normal attitude of a child. Oftentimes, the society fails to notice these simple behaviors as a problem that needs to be solved before it gets worse. The video games that are sold in the market with a goal to teach children to stand diversity has undeniably created an impression that it would enhance the knowledge of the young adults in technology and eliminated the idea that this would trigger the aggressive behavior of the player. The children will play as the main character that is given a task to protect a territory and kill the animated figures that would hinder him to win the game. The concept of this game sets the mind of the young players to fight with the use of guns and knives (O’Hehir) Frequently, learning to behave aggressively is the tested effect of media violence. This effect is also referred to as instigation of aggressive impulses, disinhibition of socialization against aggressive behavior and imitation of violence (Potter, 25). The child may not show an aggressive behavior after watching series of violent shows but the child would definitely think that aggression is acceptable in the society. Moreover, the child may not imitate the actions that were portrayed by the media, but the scenes may create fear to the young minds of the viewers. Since the information on media sources are the most accessible source of knowledge, the viewers may accustomed them and accept them as part of reality. Media violence produces short-term increases by priming existing aggressive scripts and cognitions, increasing physiological arousal, and triggering an automatic tendency to imitate observed behaviors. Media violence produces long-term effects via several types of learning processes leading to the acquisition of lasting (and automatically accessible) aggressive scripts, interpretational schemas, and aggression-supporting beliefs about social behavior, and by reducing individuals’ normal negative emotional responses to violence (Anderson et al. 81). Apparently, mass media gives all the necessary information that the people need in order to function well in the society. The media may represent the events that often occur in the society but those should not also be the basis of the messages that are being conveyed to the audience. The real events are filmed and added with more spices to make the viewers buy what the media has prepared for them. Although aggression is long associated to human, there are still factors in the society that provoke people to behave aggressively. Mass media sells products to the public. These products do not consist only of the consumer goods that the society needs in order to survive. The television programs that are being shown to the public are products of mass media that the society willingly buys. Unquestionably, the media is an influential and powerful tool to make the society a better place; however, mass media sources have been very consistent in telling only the truth to their customers. The element of the society that should help the people to lessen the societal problems become an instrument to pass the negative aspects of the society from generation to generation. However, the people can still select the products carefully. Buying violent products is telling the media to produce more (Edgar 59). The society needs to be wiser in selecting the program that would portray less aggression and help the people to participate more on salient topic in the society rather than the fiction stories that affect negatively to the lives of the viewers. Works Cited Craig A. Anderson, Leonard Berkowitz, Edward Donnerstein, L. Rowell Huesmann, James D. Johnson, Daniel Linz, Neil M. Malamuth, Ellen Wartella. The influence of media violence on youth. Psychological Science in the Public Interest. USA: Association for Psychological Science. 2004. Volume 4 Issue 3 pp. 81-110 Edgar, Kathleen. Everything you need to know about media violence. New York: The Rosen Publishing Group, 2000 Freedman, Jonathan L. Media Violence and Its Effect on Aggression: Assessing the Scientific Evidence. Canada: University of Toronto Press, 2002 O’Hehir, Andrew. The Myth of Media Violence. March 17, 2005. Daily Newsletter. 11 March 2009. Potter, James W. On Media Violence. USA: SAGE, 1999 Rutgers University. â€Å"Media Violence Cited As ‘Critical Risk Factor’ For Aggression. † ScienceDaily 20 November 2008. 11 March 2009 . Wintour, Patrick. 5 September 2007. The Guardian. 11 March 2009

The Ideal Late 1700 Woman

The Ideal late 1700 Woman Susanna Rowson and Judith Sargent Murray were women from the late 1700s who had their own image of the ideal woman. Susanna Rowson’s Charlotte: A Tale of Truth and Judith Sargent Murray’s On the Equality of the Sexes were written to educate, inform, and to guide women in the right path. Murray and Rowson hoped to change the way women were being seduced by men and the way they were viewed by society and themselves, Susanna Rowson and Judith Sargent Murray saw women’s roles in the early United States similar. In the 1700s women had a basic education of reading and writing and most were trained to become mothers and house wives. Women’s job was to take care of the children at home, cook, clean, and do housework; they were kept from the world. They had no say in politics, government, or legal issues unless their husband allowed them to do so behind the scenes. Susanna Rowson’s motive in writing Charlotte was pure, she wrote â€Å"If the following tale should save one hapless fair one from the errors which ruined poor Charlotte, or rescue from impending misery the heart of one anxious parent, I shall feel a much higher gratification in reflecting on this trifling performance, than could possibly result from the applause which might attend he most elegant finished piece of literature whose tendency might deprave the heart or mislead the understanding. † Rowson wrote Charlotte to try to change the way young women were educated. I believe she wanted parents to teach their daughters that they should listen and pay attention to the advice her parents give her, but also to teach them of the consequences can come if they decide to go in their own path instead of what her parents had planned for her. Susanna Rowson apologized for her novel because everyone expected a happy ending but received the opposite. When Charlotte’s father was on his way for her from England, she passed away after she gave birth to her illegitimate daughter Lucy Temple. Many questioned, why did Charlotte have to die? Rowson wrote, â€Å"The mind of the youth eagerly catches at promised pleasure and innocent by nature, it thinks not of the dangers lurking beneath those pleasures, till too late to avoid them. † I believe the reason Rowson did this was to try to teach young women that there are pros and cons in every decision they make. Rowson’s intentions were to guide young women live the ideal life she believed was meant for a women in the late 1700s. Mademoiselle La Rue’s life was one she approved of; she â€Å"had eloped from a onvent with a young officer, and, on coming to England, had lived with several different men in open defiance of all moral and religious duties†. Even though La Rue had been with several men she was strong and never allowed men to stray away from her path. Mademoiselle had never been seduced by a man. Susanna Rowson’s believed in order for a young women to grow up and have the ideal life, she should not only listen to her parents but also do as they say. Women in the 1700s were only given a basic education and trained to be housewives. Judith Sargent Murray’s On the Equality of the Sexes was written to give women the education they deserved and needed. Murray felt that women were capable of doing more than housework; she believed they could do the same as men if not to be better than them. To prove that women and men were equal and should be getting the same education she questions, â€Å"May not the intellectual powers be ranged under these four heads- imagination, reason, memory, and judgment? † As the Enlighten women she gave evidence to everything she said or wrote. She proved that men and women had the same capability to imagine. She wrote â€Å"but as proofs of a creative faculty, of a lively imagination†, Murray’s evidence that women had an imagination was gossiping. If women didn’t have an imagination how would they be able to come up with such interesting rumors and gossip? Murray goes on to say, â€Å"Are we deficient in reason? We can only reason from what we know, and if an opportunity of acquiring knowledge hath been denied us, the inferiority of our sex cannot fairly be deduced from thence. † She is saying if they teach women physics, psychology, and other subjects besides the basics they can prove they have the same power of reasoning as men. She then proves that women also have the power of memory, because women memorize stories and share them with others. Murray wrote, â€Å"Female would become discreet, their judgment would be invigorated, and their partners for life being circumspectly chosen, an unhappy Hymen would then be as rare as is now the reverse. † She believed if women had the same education as men, women would be not only smart but also better wives. Murray believed that everyone was born equal but society taught them that they were different. To prove that equality is given by nature she questions, â€Å"Will it be said that the judgment of a male of two year old is more sage than that of a female’s of the same age? † She compared two year olds to prove that they are equal until they get to school. Once in school society doesn’t allow women to have the same opportunity to learn. They are automatically put in different schools where they are taught different material. She goes on to say â€Å"How is the one exalted and the other depressed by the contrary modes of education which are adopted! The one is taught to aspire and the other is early confined and limited. Women are limited and that is why they do not have the same knowledge as men do. She believed women should not only get educated on not being seduced by men but also felt that they should have the same education as men. Murray believed women should have the same opportunity as men in society. Women should be able to independently provide for themselves, but due to lack of education they were not allowed to do so. Murray brings religion into her essay when she writes, â€Å"our souls by nature equal to yours; the same breath of God animates, enlivens, and invigorates us†. She proves that men are no different from women when they came into this world. God took the same breath into both men and women so what makes men better? Susanna Rowson and Judith Sargent Murray both intended to reach, like Rowson wrote, the â€Å"young and thoughtless of the fair sex†. When she wrote Charlotte: A Tale of Truth, she wanted to protect vulnerable young women from doing the wrong thing. She wrote, â€Å"Oh my dear girls—for to such only am I writing—listen not to the voice of love, unless sanctioned by paternal approbation: be assured, it is now past the days of romance. Rowson felt that women should know some of the basics to protect themself from rakes, and wanted to teach them to marry the right man. She felt as if young women were easily seduced by men. She warns the reader by writing â€Å"In affairs of love, a young heart is never in more danger than when attempted by a handsome young soldier. † For example, Charlotte decided to rebel against her parents and became romantically involved with Montraville, a man her parents disapproved of. Charlotte was a young naive 15 year old girl that got seduced by an attractive man that promised â€Å"the world† to her. He promised to marry her but instead, took her to New York, and then he abandoned her and their unborn child. Charlotte’s fate went bad when she decided to follow her heart instead of her parents. She was seduced and betrayed by the man she fell deeply in love with, this is what Rowson was trying to prevent in the lives of her young readers. In Part II of Judith Sargent Murray’s essay she wrote, â€Å"Praise is sweet to the soul; we are immediately intoxicated by large draughts of flattery, which being plentifully administered, is to the pride of our hearts the most acceptable incenses. In Murray’s essay she writes that women were seduced by men with their intellectuals. She felt that women should be educated on how not to be tempted when a man tried to seduce her. Rowson and Murray both believed that women should be educated on how to avoid falling into temptation and how to save their reputation. In the late 1700’s women were seen as the temptress and p unished for seducing men. But why is it okay that men are allowed to tempt women and get away with it? In Charlotte, Rowson tries to inform everyone that men are the temptress, not women. Charlotte falls for Montraville’s lies and betrayal because she had sympathy for him. Rowson stopped her story to put her input about women being too compassionate, â€Å"when once she has lost sight of the basis on which reputation, honor, everything that should be dear to the female heart, rest, she grows hardened in guilt, will spare no pains to bring ceeds from that diabolical spirit of envy†. Men know that once women start feeling sympathy for someone they drop the wall that they was there to protect them from becoming the fallen woman, Rowson and Murray wanted this to change. Judith Sargent Murray and Susanna Rowson were smart women that wanted young women to be educated. They differed on their opinions on how much education a woman should have. Murray believed that women should have the same education as men, and Rowson believed there was a limit on the amount of education a woman should receive. Both believed that young women should be educated to the extent where they did not fall into temptation and be marked as a temptress. In their stories they gave proof of what they believed should be done and why.

Study of Electromagnetic Clutch

ACKNOWLEDGEMENT It gives us great pleasure when a certain task is accomplished with great zeal and enthusiasm. We would like to extend our heartfelt thanks and deep sense of gratitude to all those who helped us in completing this project. First and foremost, we feel greatly indebted to Mr. D. M. SINGH and Mr. UBAID AHMAD KHAN, from the core of our heart for their constant support and valuable guidance time to time, because they encouraged and persuaded us to complete the project. We are also thankful to entire faculty members for their support.In order to complete the project we have taken help from various sites, books, study material etc. INTRODCTION A clutch is a mechanism for transmitting rotation, which can be engaged and disengaged. Clutches are useful in devices that have two rotating shafts. In these devices, one shaft is typically driven by motor or pulley, and other shaft drives another device. The clutch connects the two shafts so that they can either be locked together an d spin at the same speed (engaged), or be decoupled and spin at different speeds (disengaged). The clutch disc (centre) spins with the flywheel (left).To disengage, the lever is pulled (black arrow), causing a white pressure plate (right) to disengage the green clutch disc from turning the drive shaft, which turns within the thrust-bearing ring of the lever. Never will all 3 rings connect, with any gaps. TYPES OF CLUTCH DOG CLUTCH A dog clutch is a type of clutch that couples two rotating shafts or other rotating components not by friction but by interference. The two parts of the clutch are designed such that one will push the other, causing both to rotate at the same speed and will never slip.Dog clutches are used where slip is undesirable and/or the clutch is not used to control torque. Without slippage, dog clutches are not affected by wear in the same way that friction clutches are. Dog clutches are used inside manual automotive transmissions to lock different gears to the rota ting input and output shafts. A synchromesh arrangement ensures smooth engagement by matching the shaft speeds before the dog clutch is allowed to engage. Wet and dry A ‘wet clutch' is immersed in a cooling lubricating fluid, which also keeps the surfaces clean and gives smoother performance and longer life.Wet clutches; however, tend to lose some energy to the liquid. A ‘dry clutch', as the name implies, is not bathed in fluid. Since the surfaces of a wet clutch can be slippery (as with a motorcycle clutch bathed in engine oil), stacking multiple clutch disks can compensate for the lower coefficient of friction and so eliminate slippage under power when fully engaged. Cone clutch A cone clutch serves the same purpose as a disk or plate clutch. However, instead of mating two spinning disks, the cone clutch uses two conical surfaces to transmit torque by friction.The cone clutch transfers a higher torque than plate or disk clutches of the same size due to the wedging acti on and increased surface area. Cone clutches are generally now only used in low peripheral speed applications although they were once common in automobiles and other combustion engine transmissions. They are usually now confined to very specialist transmissions in racing, rallying, or in extreme off-road vehicles, although they are common in power boats. This is because the clutch doesn't have to be pushed in all the way and the gears will be changed quicker. Centrifugal clutchA centrifugal clutch is a clutch that uses centrifugal force to connect two concentric shafts, with the driving shaft nested inside the driven shaft. Centrifugal clutches are often used in mopeds, lawnmowers, go-karts, chainsaws, and mini bikes. Fluid coupling A fluid coupling is a hydrodynamic device used to transmit rotating mechanical power. It has been used in automobile transmissions as an alternative to a mechanical clutch. It also has widespread application in marine and industrial machine drives, where variable speed operation and/or controlled start-up without shock loading of the power transmission system is essential.Torque limiter It is also known as safety clutch. A torque limiter is an automatic device that protects mechanical equipment, or its work, from damage by mechanical overload. A torque limiter may limit the torque by slipping (as in a friction plate slip-clutch), or uncouple the load entirely (as in a shear pin). The action of a torque limiter is especially useful to limit any damage due to crash stops and jams. Torque limiters may be packaged as a shaft coupling or as a hub for sprocket or sheave. A torque limiting device is also known as an overload clutch. Electromagnetism What is an electromagnet?An electromagnet can be made by sending current through a coil of wire wound around an iron core. When current passes through a conductor, magnetic field will be generated around the conductor and the conductor become a magnet. This phenomenon is called electromagnetis m. Since the magnet is produced electric current, it is called the electromagnet. In short, when current flow through a conductor, magnetic field will be generated. When the current ceases, the magnetic field disappear. The direction of the magnetic field formed by a current carrying straight wire can be determined by the Right Hand Grip Rule or the Maxwell Screw Rule.What is magnetic field pattern? A magnetic field pattern can be represented by field lines that show the shape of the field. Magnetic field lines which are closed together represents strong field. Field direction is defined as the direction indicated by a compass needle placed in the magnetic field. Force on current carrying conductor If a current carrying conductor is placed in a magnetic field produced by permanent magnets, then the field due to current carrying conductor and the permanent magnets interact and cause the a force to be exerted on the conductor .The force on the current carrying conductor in a magnetic field depends on:- 1. The flux density of the field, B teslas 2. The strength of current, I amp 3. The length of the conductor perpendicular to the magnetic field 4. The direction of the field and current When the magnetic field, the current and the conductor are mutually perpendicular to each other then force exerted: F=IBL Newton When the conductor and magnetic field are at an angle, then the force exerted: F=IBLsin? Where; I=current, B magnetic field, L=Length of conductor ?-angle between conductor and magnetic field.Right Hand Grip Rule Grip the wire with the right hand, with the thumb pointing along the direction of the current. The other fingers give the direction of the magnetic field around the wire. The Maxwell's Screw Rules The Maxwell Screw Rules sometime is also called the Maxwell's Corkscrew Rule. Imagine a right handed screw being turn so that it bores its way in the direction of the current in the wire. The direction of rotation gives the direction of the magnetic fie ld. Electromagnetic clutch Electromagnetic clutches operate electrically, but transmit torque echanically. This is why they used to be referred to as electro-mechanical clutches. CONSTRUCTION A horseshoe magnet has a north and south pole. If a piece of carbon steel contacts both poles, a magnetic circuit is created. In an electromagnetic clutch, the north and south pole is created by a coil shell and a wound coil. In a clutch, when power is applied, a magnetic field is created in the coil. This field (flux) overcomes an air gap between the clutch rotor and the armature. This magnetic attraction, pulls the armature in contact with the rotor face.The frictional contact, which is being controlled by the strength of the magnetic field, is what causes the rotational motion to start. The torque comes from the magnetic attraction, of the coil and the friction between the steel of the armature and the steel of the clutch rotor. For many industrial clutches, friction material is used between the poles. The material is mainly used to help decrease the wear rate, but different types of material can also be used to change the coefficient of friction (torque for special applications).For example, if the clutch is required to have an extended time to speed or slip time, a low coefficient friction material can be used and if a clutch is required to have a slightly higher torque (mostly for low rpm applications), a high coefficient friction material can be used. In a clutch, the electromagnetic lines of flux have to pass into the rotor, and in turn, attract and pull the armature in contact with it to complete clutch engagement. Most industrial clutches use what is called a single flux, two pole design. Mobile clutches of other specialty electromagnetic clutches can use a double or triple flux rotor.The double or trip flux refers to the number of north/south flux paths, in the rotor and armature. This means that, if the armature is designed properly and has similar banana slot s, what occurs is a leaping of the flux path, which goes north south, north south. By having more points of contact, the torque can be greatly increased. In theory, if there were 2 sets of poles at the same diameter, the torque would double in a clutch. Obviously, that is not possible to do, so the points of contact have to be at a smaller inner diameter.Also, there are magnetic flux losses because of the bridges between the banana slots. But by using a double flux design, a 30%-50% increase in torque, can be achieved, and by using a triple flux design, a 40%-90% in torque can be achieved. This is important in applications where size and weight are critical, such as automotive requirements. The coil shell is made with carbon steel that has a combination of good strength and good magnetic properties. Copper (sometimes aluminium) magnet wire, is used to create the coil, which is held in shell either by a bobbin or by some type of epoxy/adhesive.To help increase life in applications, f riction material is used between the poles on the face of the rotor. This friction material is flush with the steel on the rotor, since if the friction material was not flush, good magnetic traction could not occur between the faces. Some people look at electromagnetic clutches and mistakenly assume that, since the friction material is flush with the steel that the clutch has already worn down but this is not the case. Clutches used in most mobile applications, (automotive, agriculture, construction equipment) do not use friction material.Their cycle requirements tend to be lower than industrial clutches, and their cost is more sensitive. Also, many mobile clutches are exposed to outside elements, so by not having friction material, it eliminates the possibility of swelling (reduced torque), that can happen when friction material absorbs moisture. HOW DOES IT WORKS The clutch has four main parts: field, rotor, armature, and hub (output) . When voltage is applied the stationary magne tic field generates the lines of flux that pass into the rotor. (The rotor is normally connected to the part that is always moving in the machine. The flux (magnetic attraction) pulls the armature in contact with the rotor (the armature is connected to the component that requires the acceleration), as the armature and the output start to accelerate. Slipping between the rotor face and the armature face continues until the input and output speed is the same (100% lockup). The actual time for this is quite short, between 1/200th of a second and 1 second. Disengagement is very simple. Once the field starts to degrade, flux falls rapidly and the armature separates.One or more springs hold the armature away from the rotor at a predetermined air gap. Engagement time There are actually two engagement times to consider in an electromagnetic clutch. The first one is the time that it takes for a coil to develop a magnetic field, strong enough to pull in an armature. Within this, there are two factors to consider. The first one is the amount of ampere turns in a coil, which will determine the strength of a magnetic field. The second one is air gap, which is the space between the armature and the rotor. Magnetic lines of flux diminish quickly in the air..Air gap is an important consideration especially with a fixed armature design because as the unit wears over many cycles of engagement the armature and the rotor will create a larger air gap which will change the engagement time of the clutch. In high cycle applications, where registration is important, even the difference of 10 to 15 milliseconds can make a difference, in registration of a machine. Even in a normal cycle application, this is important because a new machine that has accurate timing can eventually see a â€Å"drift† in its accuracy as the machine gets older.The second factor in figuring out response time of a clutch is actually much more important than the magnet wire or the air gap. It involves cal culating the amount of inertia that the clutch needs to accelerate. This is referred to as â€Å"time to speed†. In reality, this is what the end-user is most concerned with. Once it is known how much inertia is present for the clutch to start then the torque can be calculated and the appropriate size of clutch can be chosen. Most CAD systems can automatically calculate component inertia, but the key to sizing a clutch is calculating how much inertial is reflected back to the clutch or brake.To do this, engineers use the formula: T = (wk2 ? ?N) / (308 ? t) Where T = required torque in lb-ft, WK2 = total inertia in lb-ft2, ? N = change in the rotational speed in rpm, and t = time during which the acceleration or deceleration must take place. There are also online sites that can help confirm how much torque is required to accelerate a given amount of inertia over a specific time. Circuit design and analysis OBJECTIVE A control circuit is to be designed to control the motor and drive unit. The Design specifications are to be fully implemented.An incomplete circuit and equipments are given and once it is understood appropriate values for the different components should be decided. These values should allow the circuit to perform as specified. Design Specification A circuit is to be designed which is 1. Allows the angular speed of the motor to build up to a value of 20 revolutions per minute (rpm), in a time of 2 seconds (s). 2. Maintains the angular speed of 20 rpm for a time of 3s. 3. When clutch pedal is pressed it brings the machine to a halt in a time of 1s. 4.Builds up the angular speed again to 20 rpm, in a time of 2s, except this time in the opposite direction. 5. Maintains the angular speed of 20 rpm for a time of 6s. 6. Brings the machine to a halt in a time of 1s. 7. Repeats the cycle above (1-6) indefinitely when powered on. The motor must not be in dynamic braking mode at the same time as it is being driven. CIRCUIT OPERATION The initial design for the complete circuit is shown below. All references to components refer to this circuit diagram. * ANALOGUE SECTION When power is supplied to the circuit the 555 Timer switches on and its output pulses high.The initial high pulse is longer because the 555 Timer is initially at 0V. The capacitor C3 usually charges from 1/3Vcc to 2/3Vcc. However initially it has to charge from 0V to 2/3Vcc. The duration of this initial high pulse is ta = 1. 1(R6 + R7)*C3 After the initial high pulse a constant charge time is the capacitor charge time is given as tc= 0. 693(R6 + R7)*C3 (1) The output of the timer is brought up to +5V by R5. Pin 3 of the 555 Timer is at +5V when the output is at logic high.TR2 is then forward biased due to the fact that it is a NPN transistor and its collector is grounded. TR2 has a base current limiter R4. TR1 has a base current limiter R2. Transistor TR1 is now reversed bias (i. e. it is open circuited) and C1 now charges up via resistor R1. As a result the motor turns on. If suitable values of resistor R1 and capacitor C1 are used then the required waveform will be obtained for the analogue output. The duration of this low pulse is td= 0. 693(R7)*C3 (2) Pin 3 of the 555 Timer goes to 0V.TR2 is then reverse biased due to the fact that it is a NPN transistor and its collector is at +5V. Transistor TR1 is now forward biased (i. e. it is short-circuited) and C1 now discharges. The motor is now switched off. * Digital Section The voltage at the collector of TR2 provides the input clock pulse for IC2, which is configured so that it is triggered on the rising edge. Both the inputs A1 and A2 are always grounded. When the output from pin 3 of the 555 Timer is high the transistor TR2 forward biased. Therefore the input to IC2 is high. It is seen that when this occurs the output Q is high.This in turn becomes a clock signal for the J-K flip- flop (IC3) and provides Logic 1 on one of the OR-gate inputs of IC4. After IC2 is triggered, it remains high fo r a time determined by the formula tw= C2*R8*ln2 (3) C2 and R8 control the length of time of braking as well as switching the direction of the motor. When IC2 is reset a pulse is sent to the negative edge triggered J-K flip-flop (IC3). From the Data sheet for (IC3) it is seen that with the clear high and both the inputs J and K high the JK toggles.Assuming that the initial state of (IC3) is Q = 1 and Q = 0, A is initially at logic 0 and B is at logic 1. Therefore the motor will rotate to the left in an anti-clockwise direction. When IC 2 is being triggered logic 1 will be applied to both of the OR-Gates of IC4. As a result A and B will be high. The motor will now be in dynamic braking mode. When the IC 2 is reset, Q now is logic zero and Q is logic high. Therefore A will be high and B will now be zero. The motor will now run in a clockwise direction. When the IC 2 is re-triggered it will again be in dynamic braking mode.Circuit Simulation PSpice Before building the circuit that the group had modified and it was necessary to simulate its operation to see if the design we had would work correctly i. e. within the parameters. The simulation was carried out in an electrical simulation package Pspice. Pspice is a useful design tool that allows the testing of electrical circuits without the necessity to build them. It allows designs to be modified quickly and easily so that new ideas and improvements can be incorporated, before the circuit is constructed.This saves time and a considerable part of the effort when de-bugging the wiring and operation of the circuit. There were a number of reasons that the group simulated the circuit before going to the actual building stage. The main advantage was that Pspice allowed us to use theoretical values for components so we could get the timing of the circuit-very important in this case- exactly right. Although this does not mean that ‘ideal’ components may be used in practice it allowed us to narrow the range of available components that were required. This saved time when building and testing the circuit.Another advantage was that the wiring of ICs (Integrated circuit) was made simpler because we could use the Pspice schematics as a visual aid COMPONENTS USED Resistors The resistor's function is to reduce the flow of electric current. This symbol is used to indicate a resistor in a circuit diagram. There are two classes of resistors; fixed resistors and the variable resistors. They are also classified according to the material from which they are made. The typical resistor is made of either carbon film or metal film. There are other types as well, but these are the most common.Fixed ResistorsA fixed resistor is one in which the value of its resistance cannot change. Carbon film resistorsThis is the most general purpose, cheap resistor. Usually the tolerance of the resistance value is  ±5%. Power ratings of 1/8W, 1/4W and 1/2W are frequently used. Carbon film resistors have a disadvantage ; they tend to be electrically noisy. Metal film resistors are recommended for use in analog circuits. The physical size of the different resistors is as follows. METAL FILM RESISTOR| | Metal film resistors are used when a higher tolerance (more accurate value) is needed.They are much more accurate in value than carbon film resistors. They have about  ±0. 05% tolerance. They have about  ±0. 05% tolerance. Resistors that are about  ±1% are more than sufficient. Ni-Cr (Nichrome) seems to be used for the material of resistor. The metal film resistor is used for bridge circuits, filter circuits, and low-noise analog signal circuits. From the top of the photograph 1/8W (tolerance  ±1%) 1/4W (tolerance  ±1%) 1W (tolerance  ±5%) 2W (tolerance  ±5%)| Rough size| Rating power (W)| Thickness (mm)| Length (mm)| | | 3| 1/4| 2| 6| 1| 3. 5| 12| 2| 5| 15| |VARIABLE RESISTORThere are two general ways in which variable resistors are used. One is the variable resistor which value is eas ily changed, like the volume adjustment of Radio. The other is semi-fixed resistor that is not meant to be adjusted by anyone but a technician. It is used to adjust the operating condition of the circuit. Capacitors The capacitor's function is to store electricity, or electrical energy. The capacitor also functions as a filter, passing alternating current (AC), and blocking direct current (DC). This symbol is used to indicate a capacitor in a circuit diagram.The capacitor is constructed with two electrode plates facing each other, but separated by an insulator. When DC voltage is applied to the capacitor, an electric charge is stored on each electrode. While the capacitor is charging up, current flows. The current will stop flowing when the capacitor has fully charged. Electrolytic Capacitors (Electrochemical type capacitors) The most important characteristic of electrolytic capacitors is that they have polarity. They have a positive and a negative electrode. [Polarised] This means that it is very important which way round they are connected.If the capacitor is subjected to voltage exceeding its working voltage, or if it is connected with incorrect polarity, it may burst. It is extremely dangerous, because it can quite literally explode. Make absolutely no mistakes. Generally, in the circuit diagram, the positive side is indicated by a â€Å"+† (plus) symbol. Electrolytic capacitors range in value from about 1 µF to thousands of  µF. Ceramic capacitors Ceramic capacitors are constructed with materials such as titanium acid barium used as the dielectric. Internally, these capacitors are not constructed as a coil, so they can be used in high frequency applications.Typically, they are used in circuits which bypass high frequency signals to ground. These capacitors have the shape of a disk. Their capacitance is comparatively small. TRANSISTORSThe transistor's function is to amplify an electric current. Many different kinds of transistors are used in ana log circuits, for different reasons. This is not the case for digital circuits. In a digital circuit, only two values matter; on or off. The amplification abilitiy of a transistor is not relevant in a digital circuit. In many cases, a circuit is built with integrated circuits(ICs). Transistors are often used in digital circuits as buffers to protect ICs.For example, when powering an electromagnetic switch (called a ‘relay'), or when controlling a light emitting diode. (In my case. ) Two different symbols are used for the transistor. PNP type and NPN type INTEGRATED CIRCUITSAn integrated circuit contains transistors, capacitors, resistors and other parts packed in high density on one chip. Although the function is similar to a circuit made with separate components, the internal structure of the components are different in an integrated circuit. The transistors, resistors, and capacitors are formed very small, and in high density on a foundation of silicon.They are formed by a v ariation of printing technology. There are many kind of ICs, including special use ICs. DIODEA diode is a semiconductor device which allows current to flow through it in only one direction. Although a transistor is also a semiconductor device, it does not operate the way a diode does. A diode is specifically made to allow current to flow through it in only one direction. Some ways in which the diode can be used are listed here. A diode can be used as a rectifier that converts AC (Alternating Current) to DC (Direct Current) for a power supply device.Diodes can be used to separate the signal from radio frequencies. Diodes can be used as an on/off switch that controls current. This symbol is used to indicate a diode in a circuit diagram. The meaning of the symbol is (Anode)(Cathode). Current flows from the anode side to the cathode side. RELAYThe relay takes advantage of the fact that when electricity flows through a coil, it becomes an electromagnet. The electromagnetic coil attracts a steel plate, which is attached to a switch. So the switch's motion (ON and OFF) is controled by the current flowing to the coil, or not, respectively.A very useful feature of a relay is that it can be used to electrically isolate different parts of a circuit. It will allow a low voltage circuit (e. g. 5VDC) to switch the power in a high voltage circuit (e. g. 100 VAC or more). The relay operates mechanically, so it can not operate at high speed. | WIRING MATERIALWire is used to electrically connect circuit parts, devices, equipment etc. There are various kinds of wiring materials The different types of wire can be divided largely into two categories: single wire and twisted strand wire, single wire is used to connect devices (resistors, capacitors etc. together on the PWB. It is also used for jumper wiring. Twisted strand wire can bend freely, so it can be used for wiring on the PWB, and also to connect discrete pieces of equipment. If single wire is used to connect separate equip ment, it will break soon, as it is not very flexible. It is convenient to use the single tin coated wire of the diameter 0. 32 mm for the wiring of PWB. If the diameter is larger, soldering becomes a little bit difficult. And if the diameter is too thin, it becomes difficult to bend the wire the way you want it to stay.DiscussionsElectro-Magnetic CompatibilityElectromagnetic compatibility is a field which is becoming ever more important in the modern world as the use of electronic devices becomes even more widespread. It refers to the effect of electromagnetic waves on an electrical device and the degree to which this device affects other devices in the neighbourhood. This interference can act in a number of ways. Conduction – the interference occurs because of a current flow into the circuit from an external source or from one part of the circuit to another via an unintended path. e. g. a loose wire.Inductive coupling – the interference is caused by a magnetic field i n the neighbourhood of the device. This can affect the electrons flowing in the wires of the device. Capacitive coupling – the interference is caused by an electric field in the vicinity of the device. This also affects the current flowing in the device. Radiation – this type of interference is caused by waves in the electromagnetic spectrum. One example of this is radio waves being affected by radiation from a nearby mobile phoneIn the control circuit for the de-burring machine there were very few sources of EM interference.The voltage levels used meant that any waves generated would probably not be of sufficient power to affect external devices. The time was not available to measure the interference being generated by the control circuit but if a real company was planning to develop this product they would have to test it thoroughly to ensure that no compatibility problems would exist under normal operating conditions. For example in a factory environment it is possi ble that the circuit could be placed near sensitive devices such as computers.The reverse is also true the manufacturer must check to ensure that the circuit is not adversely affected by the other forms of EM interference generated in the workplace by devices such as robots, air conditioning systems and motors. One advantage of the control circuit for the de-burring machine is that it is very compact so it would therefore not be too expensive to construct a case which would shield the device from external sources of EM waves and also contain any emissions generated by the device. It would also be possible to put a filter on the analogue output from the circuit to remove any noise being picked up by the circuit.This would ensure that the analogue output was not seriously affected; however it is not really necessary. The analogue output level for the device was chosen to be 1. 2V because this gives a relatively low RPM however it could be raised so that any noise picked up would only alter the analogue output by a very small percentage. The gearing could then be adjusted to give the correct speed. The largest source of EM emissions from the de-burring machine would probably be the motor itself. This is because of the magnetic fields generated by the rotor and stator coils.As stated on the motor data sheet no testing has been carried out on the EMC of the motor but no effect has been noticed on the circuit. The simplest solution to any problems caused by the motor would be to place some form of shielding around the motor or to place the motor a distance away from the control circuit. GearingThe motor and control unit used in the construction of the circuit was not suitable for operation at the low RPM required for the drum of the de-burring machine. The lowest voltage possible speed input to the control unit was 500 rpm when the input voltage was 1V.In order to scale down the speed of the drum it was decided to use a gearing unit. In order to meet the specificati ons of the design brief it is required to drop the speed of the motor to 20rpm. Given the current design of the circuit the output voltage of 1. 2V gives a speed of 800rpm. This means that a gear ratio of 800:20 or 40:1 is required. This can be achieved by using two gear wheels with diameters in the ratio 40:1 but this would not be practical as it would require one wheel to be a great deal larger than the other. Using 2 gear wheels would also result in the drum turning in the opposite direction and this is undesirable.Gear TrainsAnother possible gear combination to achieve the required reduction in speed would be to use three cogs. The first two would be in the ratio 8:1 and then the second two in the ratio 5:1. To achieve this a ‘gear train’ would have to be formed as shown in figure 5. 1. This would save space and also correct the problem of the drum rotating in the wrong direction as the second cog would reverse the direction then the third would return it to normal. Planetary GearingAn even more compact method of gearing would be to use what is known as a planetary gear.In this type of gearing mechanism the smaller cogs are fitted inside the larger cogs as shown in figure 5. 2 below. The red cogs are held stationary and the yellow gear is connected to the input. This saves space by having the input and output on the same axis and also makes the mechanism more robust by using three central gears instead of one. This would reduce the servicing required by the machine which is an important consideration in industry. The red and yellow gears would be in the ratio of 5:1 and the blue and red gears would have to be in the ratio 8:1 to give the required 40:1 reduction.Worm GearsThe final type of gear to be considered is the worm gear (figure 5. 3). In this system the reduction factor can be very large which would allow one cog to make the 40:1 reduction? Worm gears also have the useful property of being one way. The angle between the worm and the gea r teeth is such that the worm can turn the gear but the gear cannot be used to turn the worm. This would be particularly useful as an additional form of braking for the drum of the de-burring machine however the circuit would have tobe re-designed to slow the analogue output from its full voltage to zero gradually.If this were not done the gears would lock when the motor stopped and the sudden jerk would place a great stress on the components. If the circuit was to be re-designed as suggested the dynamic braking of the motor would be redundant. Improvements to DesignAfter completion of the circuit it was evident that a number of improvements could be made to the design that would make the circuit more versatile or better suited to its task. These will be covered in this section with the aim of showing possible routes for further development of the circuit. Had time permitted some of these could have been tried in the laboratory.Perhaps the simplest of the possible routes for improvi ng the circuit is the replacement of resistors R6 and R6 with variable resistors. This would allow the forward and reverse times for the drum spinning to be altered. In this way the most suitable length of time for the parts to be de-burred can be found without the need to re-build the circuit. It would also mean that different components, requiring different lengths of time, could be de-burred in the same machine, although not at the same time. This would allow the machine to be more flexible and save the company money.By using variable resistors the times could also be fine tuned to compensate for any errors in the timing caused by the tolerances of the components used and also any extra resistance caused by the non-ideal nature of the components. Another improvement to the design would be to eliminate the extended first pulse from the 555 timer which causes the drum to rotate longer on its first cycle. Because the pulse is part of the operation of the 555 timer it is hard to alte r before it affects the analogue out so one solution would be to have some form of clutch system between the drum and motor.This would disengage the drum from the motor at start-up and not allow the drum to be turned until after the first cycle. Some form of circuit could be designed to control the clutch and only engage the motor after the first cycle has passed. Another alternative would be to have the clutch only engage after a set time equal to the duration of the first cycle. This could either be a mechanical or electrical timer and would be required to engage the clutch after 7. 746†¦ +1+8=16. 75sec. Some form of switch could also be incorporated into the circuit to reset the JK flip-flop each time the circuit is switched on.This ensures that the flip-flop always starts in the correct state and that the motor is always turning in the right direction for its first rotations. This switch would also allow the cycle to be restarted without turning the power off. Such a functi on could be simply implemented by connecting the reset pin to +5V via a switch. A final consideration when improving the circuit would be to alter the switching circuit for R6 in such a way that one resistor is always connected and connecting a second resistor in parallel with it alters the total resistance as shown in figure A.A-Alternative Switching CircuitPractical ConsiderationsWhile the motor circuit worked as required in the laboratory test, a number of other factors must be brought into consideration when the circuit is being designed for use in industry. One of the major factors has already been discussed in the section on EMC but there are many more will be briefly covered in this section. One of the most obvious differences between the test equipment and an industrial system is the motor being driven.For safety reasons the motor connected to the circuit was a low power motor but to drive a large drum a larger motor with a higher torque would be required. While the controll er card used can only support motors with an operating voltage up to 30V, a similar controller could be designed to operate at much higher output voltages while still being run off of the same circuit. Another possibility would be to run a number of motors off of on control circuit. This would allow a much greater number of parts to be de-burred without the need for an exceptionally large drum. This would introduce the problem of fan-out however.The relatively low analogue output voltage of 1. 2V would have to be increased if a large number of controller cards were to be driven. The same is true of the voltages from the OR gates controlling direction. This is problem is easily rectified by using op-amps to boost the voltage. When the system is being used in a factory environment there are also a number of environmental issues to be deal with. There could be a great deal of dust or fine particles of metal in the air from the de-burring process, it is also possible that in an automate d process the factory may not be heated.Placing the control circuit in a sealed container can resolve some of these issues, as this will prevent dust from affecting its operation. It would also be possible to incorporate shielding into this casing to improve EMC. The temperature issue is not very important, as it is unlikely that the operating ranges of the IC would be exceeded. For 74 series chips this is in the region of 0-70? C and 54 series chips have an operating range of about –50-120? C. The final consideration when constructing a system for industry would be ease of manufacture.If a large number of these machines were required the circuit would have to be laid out in such a way that it could be easily constructed on printed circuit boards. There are computer programs available to aid the designer in this process and it would be unlikely to cause a major problem. ConclusionsHaving designed and constructed the circuit it was felt that it met all of the given specificati ons although there were still a number of improvements that could have been made. These improvements have been covered briefly in the discussion section and given more time they could have been implemented in the circuit.As already mentioned the only specifications not met were that on start-up the machine should rotate for 3 seconds in one direction before braking and reversing. Using the clutch method mentioned in the discussions could solve this but the design brief given did not extend to cover the drum so has not been included in the final design. During the course of the project a number of other points became evident which greatly ease the process of designing an electronic circuit. Simulation using a computer package such as Pspice saves a considerable amount of time by allowing the circuit to be easily laid out and tested.Any changes required can be made easily without disturbing the rest of the circuit. Another advantage of Pspice is the ability to produce graphs of the ou tputs from the circuit, which can then be scaled, formatted and printed as required. To do this for the actual circuit requires very specialised and expensive equipment. In conclusion, the group felt that all objectives had been met and that the final circuit was successful in fulfilling its role. A number of important lessons were learned about the problems involved in designing a circuit to meet a real-world need and ways of overcoming these problems were found.BILL OF MATERIALS S. NO. | ITEMS| Quantity| PRICE | 1. | motor| 1| | 2. | Diode | | | 3. | capacitor| | | 4. | 555 timer| | | 5. | Relay switch| | | 6. | Coils| | | 7. | resistances| | | 8. | transformer| | | 9. | Wiring materials| | | 10. | Integrated circuit| | | 11. | Wiring board| | | References[1] Schematic Capture with Microsim Pspice Herniter Prentice Hall 3 Ed. Rd P250-252[2] http://www. emclab. umr. edu/An Introduction to EMCUniversity of Missouri-Rolla EMC laboratory[3] http://reality. sgi. com/csp/scvemc/emcdef. tmlEnsuring Compatibility Between the Electromagnetic Environment and Electric and Electrical Devices Kimball William, Chairman, IEEE EMC Education Committee[4] http://www. howstuffworks. com/gears. htmHow gears Work[5]www. scribd . com[6]www. mechanicalprojects. comBackground Reading * Digital Fundamentals Floyd Prentice Hall 7 Edition t h. * Introductory Circuit Analysis Boylestad Prentice Hall 9 Edition t h. * Machine Design – R. K. Rajput. * Kinematics Of Machine – R. S. khurmi. * Automobile Engineering – R. K. Rajput | | |

Theory of Language

1. THEORY OF LANGUAGE The theory of language underlying Duysel Learning was derived from a view of proposed by Turkish Linguistics in the 2000s. Duysel Learning Method involves both the learning of language knowledge and the cultivation of language skills, with the emphasis on both the form and the content of a language. In teaching practice, its all-inclusive nature requires English teachers to select special and effective teaching methods in conformity with its special tasks to avoid turning it into a pure practical course of oral English or a pure theoretical one on grammar.Regardless of all criticism it has received, the grammar-translation method has been an indispensable method in English teaching as well as a necessary step in the cultivation of students’ communicative ability in a non-English environment. A person cannot have successful communication before having a correct mastery of language rules. Although the applicability of the communicative method has been widel y accepted, this method is confronted with some practical problems.I think we should search for a fusion between the traditional teaching method and the modern teaching method with a more rational attitude based on the learner’s practical ability and request that is, adopting a new method fusing the two methods together in one class of comprehensive English. 1. THEORY OF LEARNING Language is the most important aspect in the life of all beings. We use language to express inner thoughts and emotions, make sense of complex and abstract thought, to learn to communicate with others, to fulfill our wants and needs, as well as to establish rules and maintain our culture.Language is a subtle and complex instrument used to communicate an incredible number of different things, but for our purposes here we can reduce the universe of communication to four basic categories: information, direction, emotion, and ceremony. The first two are often treated together because they express cogniti ve meaning while the latter two commonly express emotional meaning. Language is not learned primarily by learning the â€Å"rules† but rather by first listening to and understanding the spoken language and then practicing speaking.Occasionally, however, learning of rules can help many adults learn and use the language. Just do not make rules the focus of the course. While repetition and memorization can play an important role in language learning, they cannot by themselves insure that students will be able to use the language for any real purpose. Repetition and memorization, if used, must be accompanied by other activities requiring the application of the learned patterns in novel situations and with variation in vocabulary and even structure. . DESIGN a. Objectives/Syllabus In Duysel Learning Method, grammar teaching is not intended for studying grammar but help students to grasp language rules and fulfill listening, speaking, reading and writing practice in a better way. A s a result, teachers should create situations for real activities according to students’ daily life to guide students to understand, grasp and use grammar correctly in such situations.I once adopted a four-step method including introduction, imitation, summary and application to promote grammar teaching at comprehensive English class. In the introduction section, the teacher gives oral demonstration on some original or relevant sentences related to a certain grammar rule in order to introduce it. Selected examples should be in conformity with certain communicative situations hence putting it across to students to what situations this grammar rule applies.In the imitation process, students are required to have oral imitation of some expressions fit for the given situation after understanding examples, which further establishes a pattern for correct use of grammar knowledge in a new situation as well as checks whether they have understood the given knowledge points or not. In t he summary part, students are guided to sum up grammatical rules and points by analyzing specific situations themselves so that they will enjoy the joy of success. Students are expected to take notes so as to accumulate material for review.In the last step, some real situations are set to help students to practice using the learnt grammatical knowledge to have communication. Once they find that they can apply grammar to real communication and specific tasks instead of memorizing grammatical rules, students’ learning enthusiasm will be stimulated and their ability of independent analysis and solving problems will be cultivated as well. b. Types of Learning and Teaching Activities Duysel Learning Method emphasizes students’ comprehensive training in listening, speaking, reading, writing and translation.Due to the specialty of listening and speaking training, they are usually dealt with separately while other three skills are mainly trained through the learning of texts. As for listening and speaking, students are expected to follow classes given in English, to understand short conversations, lectures as well as reports with familiar topics, simple structure and a speed of 120 words per minute, to ask and answer and retell based on relevant listening material, to make conferred presentations based on familiar topics after adequate preparation.Obviously, the communicative method helps to achieve the teaching goal in listening and speaking practice. In practice, teachers may ask students to listen to tapes, do exercises and have discussions based on hot issues with teachers’ checking and instruction; they may also analyze some difficult points in listening material and have more extensive learning of new words and expressions. However, those who have been accustomed to the traditional method tend to keep silent and think little of this method since they cannot learn sufficient knowledge and language points.As a result, teachers should use the g rammar-translation method at times with the communicative method as the main line. For instance, some difficult points at the linguistic level can be explained with the traditional method. Students’ reading, writing and translation skills are mainly trained in learning texts. Teachers are expected to base their teaching on texts to give students certain information and language knowledge first of all by focusing on the translation and understanding of texts and then establish new situations beyond the texts for practice of communicative skills.I once adopted a four-step method including preparatory reading, listening and answering, communication on text and conferred communication in the text teaching process, achieving a natural transition and fusion of grammar-translation training and communicative training. In the first step, students are required to preview a text beforehand with their grammar-translation experience in which they can make sure about some new words, the gi st of the text and some questions and therefore have the next day’s class with full preparation.In the second step, the teacher first asks students to correct their pronunciation and intonation by imitating the tape and then plays the tape once again for students to answer questions or make judgments so as to check their preparatory reading. In the third step, the teacher may guide students to have communication in the context related to the text and help them to solve some problems in key words, sentences and understanding of content they displayed in the previous two steps.When explaining key words and sentences, the grammar-translation method should be used to deepen students’ understanding of the text and improve their ability to use language correctly and flexibly through right communication on the text. In the last step, students’ enthusiasm for communication is fully encouraged. Here the communication in this step is different from that in the previous st eps since teachers need to employ a variety of advanced teaching methods to create language situations and communicative tasks which originating from text while going beyond of it.Students are able to apply what they have learnt to real communication through continuing writing texts, having simulated dialogues, having role-plays, having discussions and so on, hence achieving the purpose of communicating ideas through language. c. Learner Roles Learners have to participate in classroom activities that were based on a cooperative rather than individualistic approach to learning. Students have to become comfortable with listening to their peers in group work or pair work tasks, rather than relying on the teacher for a model.They are expected to take on a greater degree of responsibility for their own learning. d. Teacher Roles Teachers have to assume the role of facilitator and monitor. Rather than being a model for correct speech and writing and one with the primary responsibility of making students produce plenty of error-free sentences, the teacher have to develop a different view of learners’ errors and of her/his own role in facilitating language learning. e. The Role of Instructional Materials Classical texts and carefully compiled texts according to grammar system are used.The materials usually consist of three parts: grammar, vocabulary, and text. The main functions of the materials used in Duysel Learning are presenting and reinforcing grammar rules and new words, and offering cultural information. Additionally, exercise handbooks, cue cards, activity cards, pair-communication practice materials. And student interaction practice booklets are employed in the activities with the aim of improving communicative skills. f. The Role of Native Language The role of language in learning cannot be over-emphasized. Language is the prime resource teachers have and use for mediating learning.When learning languages, then, teachers and students are working with language simultaneously as an object of study and as a medium for learning. In teaching languages, the target language is not simply a new code – new labels for the same concepts; rather, effectively taught, the new language and culture being learned offer the opportunity for learning new concepts and new ways of understanding the world. The target language should be used not only during communicative activities, but also for explaining the activities to the students or in assigning homework. However, native language is only used in making translation. . Feelings of Students Learner’s feelings are very important because students will be more motivated to study a foreign language since they will feel they are learning to do something useful with the language. They are given an opportunity to express their individuality by having them share their ideas and opinions on a regular basis. h. Evaluation The teacher evaluates not only the students’ accuracy, but also t heir fluency. Use an integrative test which has a real communicative function. To assess students’ writing skill, a teacher might ask them to write a letter to a friend.Written tests in which students are asked to translate from their native language to the target language or vice versa are also used. Questions about the foreign culture or questions that ask students to apply grammar rules are common. i. Treatments of Errors Errors of form are tolerated during fluency–based activities and they are seen as a natural outcome of the development of communication skills. But in the translation part, having the students get the correct answer is considered very important. If students make errors or don't know an answer, the teacher supplies them with the correct answer.