Wednesday, January 29, 2020

Active and Passive - Devices Essay Example for Free

Active and Passive Devices Essay Electronic components are classed into either being Passive devices or Active devices. Active devices are different from passive devices. These devices are capable of changing their operational performance, may deliver power to the circuit, and can perform interesting mathematical functions. While a device that does not require a source of energy for its operation. Active Devices An active device is any type of circuit component with the ability to electrically control electron flow (electricity controlling electricity). In order for a circuit to be properly called electronic, it must contain at least one active device. Active devices include, but are not limited to, vacuum tubes, transistors, silicon-controlled rectifiers (SCRs), and TRIACs. All active devices control the flow of electrons through them. Some active devices allow a voltage to control this current while other active devices allow another current to do the job. Devices utilizing a static voltage as the controlling signal are, not surprisingly, called voltage-controlled devices. Devices working on the principle of one current controlling another current are known as current-controlled devices. For the record, vacuum tubes are voltage-controlled devices while transistors are made as either voltage-controlled or current controlled types. The first type of transistor successfully demonstrated was a current-controlled device. What are Passive Devices? Components incapable of controlling current by means of another electrical signal are called passive devices. Resistors, capacitors, inductors, transformers, and even diodes are all considered passive devices. Passive devices are the resistors, capacitors, and inductors required to build electronic hardware. They always have a gain less than one, thus they can not oscillate or amplify a signal. A combination of passive components can multiply a signal by values less than one, they can shift the phase of a signal, they can reject a signal because it is not made up of the correct frequencies, they can control complex circuits, but they can not multiply by more than one because they lack gain. INTEDGRATED CIRCUITS Analog circuits Most analog electronic appliances, such as radio receivers, are constructed from combinations of a few types of basic circuits. Analog circuits use a continuous range of voltage as opposed to discrete levels as in digital circuits. The number of different analog circuits so far devised is huge, especially because a circuit can be defined as anything from a single component, to systems containing thousands of components. Analog circuits are sometimes called linear circuits although many non-linear effects are used in analog circuits such as mixers, modulators, etc. Good examples of analog circuits include vacuum tube and transistor amplifiers, operational amplifiers and oscillators. One rarely finds modern circuits that are entirely analog. These days analog circuitry may use digital or even microprocessor techniques to improve performance. This type of circuit is usually called mixed signal rather than analog or digital. Sometimes it may be difficult to differentiate between analog and digital circuits as they have elements of both linear and non-linear operation. An example is the comparator which takes in a continuous range of voltage but only outputs one of two levels as in a digital circuit. Similarly, an overdriven transistor amplifier can take on the characteristics of a controlled switch having essentially two levels of output. * A Hall effect sensor is a transducer that varies its output voltage in response to a magnetic field. Hall effect sensors are used for proximity switching, positioning, speed detection, and current sensing applications. * A current sensor is a device that detects electrical current (AC or DC) in a wire, and generates a signal proportional to it.The generated signal could be analog voltage or current or even digital output.It can be then utilized to display the measured current in an ammeter or can be stored for further analysis in a data acquisition system or can be utilized for control purpose. Digital circuits Digital circuits are electric circuits based on a number of discrete voltage levels. Digital circuits are the most common physical representation of Boolean algebra, and are the basis of all digital computers. To most engineers, the terms digital circuit, digital system and logic are interchangeable in the context of digital circuits. Most digital circuits  use a binary system with two voltage levels labeled 0 and 1. Often logic 0 will be a lower voltage and referred to as Low while logic 1 is referred to as High. However, some systems use the reverse definition (0 is High) or are current based. Ternary (with three states) logic has been studied, and some prototype computers made. Computers, electronic clocks, and programmable logic controllers (used to control industrial processes) are constructed of digital circuits. Digital signal processors are another example. http://aanaedwards.hubpages.com/hub/Active-Passive-Devices 2011 | Aana Edwards | Silicon City, CA http://en.wikipedia.org/wiki/Electronics

Tuesday, January 21, 2020

Living in the 1600 and 1700s Essay -- religion, diseases, historical a

Several people who live today have distaste for manual labor, such as farming, making crafts, laundry, or cleaning. However, all of these tasks were included in the list of daily chores for colonial children. While some detest tiring work, others cannot stand boredom. No matter how tired you were, you would still have to go to church once or twice a day on the Sabbath. The only way to get out of work would be getting sick. Because the colonists’ only medicine was from plants, the chances of dying or being scarred for life were high. If living the 1600s and 1700s could be described in one word, it would be tiresome. After all, diseases were as common as air, everyday was spent working or at least being productive in some way, and if there was time for a respite, it would be on the Sabbath, a day dedicated to God. Diseases were common and widespread in the colonies. Countless times, epidemics have struck everywhere, from major cities to small countryside. Characterized by horrid rashes, smallpox was a despised disease that existed throughout history and throughout the colonies. If y...

Sunday, January 12, 2020

A political conflict Essay

For colored citizens prior to the Civil War, freedom was a distant dream as the age-old human history of slavery heightened within the American heartlands even after the Declaration of Independence. When the American nation proudly held a new constitution, it was supposedly a determined effort to uphold a balance of power symbolizing the freedom from political, cultural and moral oppression yet colored individuals were treated as less civilized citizens and slavery was reinforced by and among the rich landowners capable of maintaining numerous slaves. As slavery provided free labor and flourishing the slave trade, African black slaves exported from Africa increased the slave population in the United States by 4 million (US 1860 Census). The Quakers of Pennsylvania as an antislavery force that gained strength throughout the country paved the way for the gradual abolition of slavery in the US northern states. New York and New Jersey became the last Northern states to abolish slavery (Grant 2001). A political conflict however ensued as slavery supporters insisted lifting any barriers to slave trade while sanctioning the acceptance of slavery based on the biblical scriptures as â€Å"God’s plan to Christianize† the Africans (Hartz 1955). Slavery for the supporters was seen as an economic, social and cultural life which actually lengthened the arguments for the continued adherence to slave labor. Divisive means were also used to promote scientific experiments to demonstrate the superiority of the whites and the inferiority of the blacks (Colley 1859), where anatomical proportions of the brain justify blacks doing hard labor which upon careful contrast does not measure up to the actual inequalities committed within the period. As the debate on slavery grew, disrespect for the law also rose. Sooner than expected, the American slaves who were ill-treated began to resort to acts of violence like burnings barns, arson and even murder. The famous acts of rebellion in Saint Dominique (1790’s) and Virginia (1800’s) paved the way for the 1831 rebellion that killed sixty whites in Virginia tougher slave codes and prohibitions for the slaves that was heavily emphasized in William Lloyd Garrison’s The Liberator as provided by Tocqueville. No amount of compromise could weed out the institution of slavery except upon the culmination of Lincoln’s election in the 1850’s and the legal implementation of the Thirteenth Amendment (Zinn 2001). II. Blacks living in free states Blacks actually lived a precarious existence within the Free states prior to the Civil War as many were still considered slaves. Many of the free blacks, who were skilled craftsmen, were tolerated because of their abilities as their earnings contributed to the general economy yet none of the free blacks ever rose higher than the status of small tradesmen, builders or nautical employees as they soon became a source of revenue as property taxpayers (Toqueville 1969). Forten, a free black girl from the Northern states gained education in Salem and observed that runaway slaves in Boston were treated as mere slaves and returned to their masters instead of being set free (Forten 2000). Although conditions were far better for the Blacks in the Northern states, very few blacks had their voices heard. Segregated facilities still existed in the North and they were usually denied entrance to the best hotels and restaurants (Jordan 1995, 218). Although schools in New England were usually integrated, those in the Midwest were generally not and economic discrimination continued as the Blacks fought to compete with large numbers of recent European immigrants for job opportunities and almost always lost (Cartmell 2004). During this same period, Norfolk’s free blacks frequently helped enslaved African-Americans to buy their freedom, and in a few instances became slave owners themselves (Toqueville 1969). Harsh laws soon prevailed as freedoms enjoyed by free blacks were soon curtailed because they were still unable to vote. The blacks were often stereotyped as unruly citizens that soon led other free blacks to move further north and help their relatives escape from increasing mistreatment. III. Blacks in the Army In the battle for the emancipation of slavery, slaves contributed to their freedom by laboring and rallying behind the scenes. At the onset of war, the free Black Virginians supported the Confederacy even though they were treated as inferiors and lived in a state of fear. Many were motivated to work with the Confederate States with the hope that someday restrictions against them would be lifted while anticipating a post war gratitude from the white counterparts they fought with (Jordan 1995, 216). The efficiency of the army during the Civil War also saw slaves working as cooks, nurses, hospital attendants, blacksmiths, etc and not getting any pay while free blacks however who served the army were paid the same rate as privates (Cartmell 2004, 176). Less than a dozen African Americans actually served in combat, one of those who did was Holt Collier who served as a sharp shooter and cavalryman of the Texas Brigade (Cartmell, 2004). Thus suffice for us to say that the Blacks fought behind enemy lines as soldiers and were inspired by their involvement yet many were denied enlistment. IV. Blacks who remained in the confederate states Prior to the Civil War, black slaves in Louisiana enjoyed certain privileges that addressed their needs as slaves like being able to sue their masters for abuse (Edge and Downs 2003). Free Blacks were free to own property and conduct business while enjoying liberties absent from other Southern states while slaves were permitted to celebrate their African culture at the markets (edge and Downs 2003). In Virginia, Blacks were criticized for being indifferent to the success of the Southern rebellion as a few free blacks pretended to be slaves in order to gain urban employment like Jim Butler who worked at Richmond’s Exchange Hotel (Jordan 1995, 215). For most Blacks during the period, social injustice prevailed distressingly as slaveholdings in the vast majority of the Southern states continued. Treatment bordered from harsh to inhumane as slavery allowed the master to punish the blacks who failed to perform his duties as related in Stampp, â€Å"Now, I speak what I know, when I say it is like ‘casting pearls before swine’ to try to persuade a negro to work. He must be made to work, and should always be given to understand that if he fails to perform his duty he will be punished for it (Stampp 1956). Slave overseers were authorized to whip the non compliant slaves while free blacks were monitored well by patrols. Escapees were either maimed of killed as slaves were at risk of loosing their family members to punishing masters according to Stampp. Slave-breeding was encouraged to encourage the economic interest of Southern planters for easy access to black workers to retain whole black families to work for them (Loveland 1986). As a backlash to the Southerners who mistreated their black slaves, many Southern blacks fought for the Confederate cause as a patriotic duty in part and as slaves in full. Yet for many who knew and acknowledged the Northerners cause, most Black soldiers in the Confederate states fled to the Northern lines and fought with them. The slave’s knowledge proved important in winning the war as their familiarity became an advantage for the Northern regiment. V. Life after the war When the American Civil War broke out in 1861, it heavily marked the end of slavery and thereby freeing nearly four million slaves in America (grant 2001). But the history of unfair treatment of the US on its own people easily portrayed hypocrisy on its citizens as Blacks remained objects of racial discrimination. It goes into reason that politicians used their might to support the rich sectors’ relevant refusal to grant equal rights to blacks. Another point of discussion was the political agenda behind the support for the anti-slavery campaigns when civil rights and voting rights became an important issue. Granting the Black community access to their own rights would naturally mean higher pay for the earners and lower profits for the capitalists. While supportive of the anti-slavery, political leaderships, not wanting to loose the support of their corporate and rich allies despite knowledge of unfair treatment would seek to ignore such acts. Such was the extent and tentacles of power used for gains that demean the spirit of the Declaration of Independence (Hartz 1955). V. The fight for equality for the next 100 years As a wave of democracy rose to deafening heights, Black struggle for acceptance rose to free them from the binding ties of slavery (Markoff 1996, 163). Although slavery was emancipated, marginalized sectors continue to insist on freedom from mockery and racial segregation based on skin color (Loveland 1996). Struggles continued as schools in the South refused to adapt to integration that led to riots commandeered by the blacks held in opposition against the whites who refused desegregation and tolerate intimidation and murders led by its famous Ku Klux Klan movement (Zinn 2001). Few of the KKK’s activities received massive media attention until the murder of a 14 year old Emmet Till in 1955 that led to a confrontation against issues of racism. As women gained equal rights in 1960’s, racial discrimination slowly ebbed that gave way to several centuries of struggle fr the blacks to gain a state of freedom. VI. Conclusion Why slavery had to be ended by extreme force? If it were probably left to the government the rights of the ordinary slaves would have been left as it was. Heavy opposition and criticism did not bring an end to slavery. Even the national government who endorsed anti-slavery Republicans into office to resolve the issue was most of the time indecisive. The slave- owning southerners and the anti-slavery northerners could not see eye to eye on the ultimate extinction of slavery. In the 1850’s open hostilities were already brimming on several states which finally triggered hostile actions. Although many favored and sought some sort of a compromise, the stronger point of rejection for one was triggered by fear that a conspiracy is threatening to bring down the American republic. Disagreements arise to a crescendo as political parties split and Lincoln’s war goals came into light to solve the problem by means of force when no alternative action could be seen to solve the conflict. Greed for power was the root of such warfare nurtured among many that sought to restrict freedom and pursued rampant acts of discrimination. Such tentacles of power used for corporate gains demean the spirit of independence in this nation’s history. Bibliography Cartmell, Donald. 2004. The Civil War Up Close: Thousand of Curious, Obscure and Fascinating Facts. Career Press. Colley, Thomas. 1859. Civilized America. Bradbury and Evans. Edge, John T. and Downs, Tom. 2003. New Orleans. Lonely Planet. Forten, Charlotte L. 2000. A Free Black Girl Before the Civil War: The Diary of Charlotte Forten, 1854. Capstone Press. Grant, Donald L. 2001. The Way It was in the South: The Black Experience in Georgia. Atlanta: University of Georgia Hartz, Louis. 1955. The Liberal Tradition in America: An Interpretation of American Thought Since the Revolution. New York: Harcourt. Jordan, Ervin L. 1995. Black Confederates and Afro-Yankees in Civil War Virginia. Virginia: University of Virginia. Loveland, Anne C. 1986. Lilian Smith, A Southerners Confronting the South: A Biography. Baton Rouge: Lousisiana State University. Markoff, John. 1996. Waves of Democracy: Social Movements and Political Change. Pine Forge Press. Stampp, Kenneth M. 1956. The Peculiar Institution: Slavery in the Ante-Bellum South. Survey Tocqueville, Alexis. 1969. Democracy in America, eds. J. P. Mayer, trans. George Lawrence. New York: Harper Collins. Zinn, Howard. 2001. People’s History of the United States. New York: Harper Collins.

Saturday, January 4, 2020

The Dangers of Overusing Computers - 720 Words

Computers have been around for many years and have helped our society grow and communicate with each other from long distance. According to Claudia Miclaus from â€Å"The Harmful Influence of the Computer,† computers are commonly used everywhere such as in school, at home, businesses and so on (Miclaus 1). Though the computer is very helpful to our society, computers can actually cause mental and physical health problems as well as social disorders. Most people that use a computer often are in danger of risky serious mental and physical health. Computers can cause major mental health problems such as anxiety. Miclaus states that most people that often use computers often have anxiety, low energy, emotional instability, and lack of work efficiency (2). Emotional conflict can lead to affecting a person’s daily life and the people he or she interacts with. Most people that suffer from anxiety, depression, or loneliness often go to the computer to forget their problems they may be facing in their lives. Joanna Saisan, M.S.W., Melinda Smith, M.A., Lawrence Robinson, and Jeanne Segal Ph.D. from â€Å"Internet and Computer Addiction† quotes, â€Å"†¦too much time online can make things worse† (Saisan M.S.W. et al. 2). Most people that over use computers often have difficultly controlling their emotions. Computers can also lead to physical health problems such as strains on muscles and the risk of obesity. Tina Sieber from â€Å"5 Reasons Working With Computers Is Bad For You How to Stay Healthy,†Show MoreRelatedIs Technology A Powerful Tool? Today s Society?838 Words   |  4 PagesThe Effects Overusing Technology Technology is a powerful tool in today’s society. Most people own some sort of technology and use it on a daily basis whether it be a cell phone, computer, GPS, or a tablet. Technology helps us in many different ways by being able to complete tasks easier, and be connected to people we cannot see daily. Text messages, emails, apps like Snapchat, Skype, or FaceTime help us stay connected to people far or near. There is an app for almost anything you need on mostRead MoreThe Effects Of Internet Technology On Society s Society Essay903 Words   |  4 PagesThe Effects of Overusing Technology Technology is a powerful tool in today’s society. Most people own some sort of technology and use it on a daily basis, whether it be a cell phone, computer, GPS, or a tablet. Technology helps us in many different ways by being able to complete tasks easier, and be connected to people we cannot see daily. Text messages, emails, apps like Snapchat, Skype, or FaceTime helps us stay connected to people far or near. Wireless internet has allowed internet accessRead MoreThe Double Edged Sword We Call Technology1098 Words   |  5 Pagescommunication, mental illnesses, environmental issues, and other ways. Today, it is not only recommended, but it is almost demanded that we have the latest technological gadgets in the industry. These things involve technologies such as phones, computers, tablets, and things that we need in our everyday lives. Notice how I said the word need? According to Miriam-Websters online dictionary the definition of the word â€Å"need† is â€Å"a physiological or psychological requirement for the well-being of an organism†Read MoreThe Negative Side Of Social Media886 Words   |  4 Pagessocial networks are changing what we define â€Å"social†. Instead of face-to-face communication, today’s generation speaks through technology such as, texting. I have to agree with the negative side though because the internet actually has much more dangers rather than help. In conclusion, social media is about similar to a drug because, it changes our personalities, takes us off-task, and exposes us to the dangerous people. As I mentioned, drugs like social networks will give a change to our personalitiesRead MorePros and Cons of Using Electronic Gadgets in Studying1694 Words   |  7 PagesSome scholars actually have stated that our brains are evolving and changing due to exposure–repeated exposure–to various activities on the computer. These changes have impacts on the traditional teaching-learning situations in classrooms and schools–particularly if one want to keep or focus the attention of students. In short, these so-called traditional teaching-learning style and practices might not be effective for the roaring digital minds. Does the use of digital technology really improveRead MoreThe Dangers Of Too Much Technology1296 Words   |  6 Pagesas the amount of human interaction that occurs in the classroom. In recent years, there has been a growth in technology within classrooms. Currently, technology has begun to dominate various teaching methods throughout the education system. â€Å"The dangers of too much technology in education† article authored by Cody Laplante talks about Khan Academy, a non-profit organization that provides schools with online video lectures and expounds on how video lectures are being adopted as a new means of teachingRead MoreThe Negative Effects of Social Networking on Teenagers1547 Words   |  6 Pagesfor them. It is true that the social network is a decent method to communicate with friends. However, social networking has negative effects on teenagers in regard to their academic outcomes, their socialization, and their behavior. First of all, overusing social networking in adolescences has direct impact on academic outcomes. Nowadays, social networking has turn into norm for teenagers. Some teens think that it is necessary to participate in all or some social networking sites in order to maintainRead MoreVirtual Reality and the Gaming Industry1363 Words   |  6 Pages(Biocca and Levy 1995). Constantly using virtual reality will cause isolation from the societies because the person already made his or her own social area which only exists in the virtual world. VR will provide a communication environment in which the dangers of deception and the benefits of creativity are amplified beyond the levels that humans currently experience in their interpersonal interactions (Biocca and Levy 1995). It could lead to low self-esteem, feelings of worthlessness and insignificanceRead MoreHow Technology Has Changed Our Life1988 Words   |  8 Pagesinternet allows us to perform many tasks for example, writing a research report or listen to the latest justin bieber song. So are we taking the internet for granted and not acknowledging everything it does for us, or are we taking advantage of it by overusing it? Technology is seen as a method that helps everyone from all around the world to stay in touch with their significant others, but Tanya Schevitz, who is a spokesperson for, â€Å"Reboot’s National Day of Unplugging,† made some research and came toRead MoreImpact Of Technology On Society : University Of Windsor Abstract Technology1766 Words   |  8 Pagesdramatically affected the way we live in this present society. From entertainment devices such as the television, communication devices such as the iPhone, life-saving devices such as defibrillators and educational devices such as Microsoft and Apple computers, technology appears to have numerous benefits in certain fields of human life. Today, technology and human lifestyle are like a set that cannot be separated. According to research conducted by technology enthusiast Lulu Chang, the average human spends