Photodiode Process Essay Example for Free

Photodiode Process Essay * a type of photodetector capable of converting light into either current or voltage, depending upon the mode of operation. The common traditional solar cell used to generate electric solar power is a large area photodiode. * a semiconductor with a p-n junction PRINCIPLES OF PHOTODIODE * Photons is the source of its energy * Energy can be solved by the equation: W=hf Where: h =Planck’s constant= 6.624Ãâ€"10-34 f = frequency * The frequency is, in turn, directly related to the wavelength (distance between successive peaks) of the traveling wave by the following equation: = Vf = wavelength f = frequency V = velocity of light * 1 lm=1.496Ãâ€"10-10 W * Light intensity is measured in lmft2, footcandle (fc), or Wm2 * The operation of the photodiode is limited to reverse bias region. * The application of light will result to the transfer of energy(photons) * Dark current current that will exist without illumination. APPLICATIONS * employed in an alarm system. * reverse will continue to flow as long as the light beam does not broken * used to count items in the conveyor’s belt. * item passed the light beam then it will be broken the current will drops to the dark current level and the counter will increase. PHOTOTRANSISTOR * A photoelectric device with photosensitive collector-base p-n junction. The current induced by photoelectric effects is the base current of the transistor. PRINCIPLES OF PHOTOTRANSISTOR * If we assign the notation I , for the photoinduced base current, the resulting collector current, on an approximate basis is Ic≅hfe I * An increase in light corresponds with the increase in collector current. APPLICATIONS * Punch-card readers * Computer logic circuitry * Lighting control * Level indication * Relays * Counting systems * High isolation AND gate using three phototransistors and three LED as is aid. * The high isolation simply refers to the lack of an electrical connection between the input and output circuits.

The Great Depression :: History

The Great Depression The Great Depression is comparable to Lennie and George's life. I would like to give a comparison of George Milton and Lennie Small to the Great Depression. The time that this story took place was during the Great Depression. John Steinbeck captured the reality of this most difficult time. During the Great Depression people needed to travel together to share chores and duties to make a living until something better came along. That is the way George and Lennie traveled. They traveled together to take care of each other but George took care of Lennie the most, because he was always getting in trouble. "You do bad things and I got to get you out." (Of Mice and Men p.11). During the Great Depression money was very scarce. You had to travel around to find a job in order to make money to survive. Lennie and George were in that type of predicament. Keeping enough money until the next job was difficult because prices were rising during the Great Depression and you had to budget your money. During this depression most people worked on farms because after the stock market crashed people realized that the reason the stock market crashed was because farms were not producing enough goods. People started to work on farms more to help everyone. Lennie and George worked for ranches and also in the fields. "He's a good skinner. He can rassel grain bags, drive a cultivator. He can do anything." (Of Mice and Men p.22). If you really look closely, George and Lennie's way of life and the Great Depression have a good deal in common. George and Lennie were outcasts in life. George Milton was small in size and a very smart man compared to Lennie. He was actually only of average intelligence. Lennie Small was a large person and very retarded. Since Lennie was so retarded he did not grasp the things that were happening around him. For example, if someone became upset about anything he would grab them and hold and squeeze until they stopped moving. Lennie would accidentally harm them and that is how he got inck smoke into the environment constantly. This disgusting smog stains buildings, covers trees, and hovers above many of our major city in large masses. Automobiles also contain some fluids that can be deadly to us and our wildlife. We often hear of gasoline spills by tanker trucks or by ships, both of which are meant to supply our automobiles with fuel.

Opportunity to participate in SkillsUSA Essay

One of the benefits of attending a vocational high school is the opportunity to participate in SkillsUSA. Preparing for SkillsUSA was one of the most challenging and nerve racking experiences in my life. SkillsUSA is an organization of students and teachers working together to help its members become responsible, hard working, and dedicated young adults. At the beginning of my junior year in high school, my shop instructor approached me and told me about SkillsUSA, and also the events that pertained to information technology. It took me a few moments to realize that he was encouraging me to participate. I read through the information packet my teacher gave me and noticed that SkillsUSA was a lot bigger than I realized. SkillsUSA is not only about being skilled in the trade you are studying, it is about being an outstanding citizen, and giving back to your community in any way you can. The first thoughts that popped into my head were â€Å"Am I ready for this?† I chose to compete in the robotics and automation technology contest. I have always been interested in robots and how they work. Until then, I had no experience working with robots so I was really nervous, I did not have much confidence in myself. Not only did I have a few months to learn everything I can about robotics while keeping up with my schoolwork, and balancing my part-time job, but I also had to evaluate myself as a person. I was on the Internet and at the library every spare minute I had learning everything I could. I ordered kits off the Internet to practice working with robots so there were no surprises during the competition. It was hard work, but it paid off. Although I did not place at the competition, I did really well considering I started learning about robotics five months prior to the competition and I was competing against students who had years of experience on the robotics team at their high school. Becoming a SkillsUSA member means you must make a pledge to be prepared, to be diligent, to practice, work hard, to respect your trade, and have a good reputation with your peers, coworkers, parents, employers, and teachers. Making a pledge this important demonstrates how committed I am to become a better citizen. I made the pledge to myself, even though I did not become an official SkillsUSA member. I found I have more confidence and take pride in everything I do whether it is taking a test, completing homework, or even dealing with difficult customers at my job. Setting these standards for myself is important to me. When I look back on my accomplishments I realize that I did not have to set my mind to put forth my best effort because what I use to think of as my â€Å"best effort† is now second nature. In those five months I feel like I have grown as person more than any other period in my life.

Essay about Roosevelt Vs. Hoover and the Great Depression

Roosevelt and Hoover The Great Depression drastically changed Americas definition of Liberalism. Prior to the onset of the depression, in the roaring twenties, policies of laissez-faire were considered liberal, radical, revolutionary, and even democratic. This was due to the fact that revolution was a horrifying notion and not until after the laissez-faire and the system of free market fails in the 1920s do people begin to look about for alternatives. The time when people starting to seek alternatives was at the onset of the depression when Americas political views drastically change. As the Great Depression, started in 1929, America began to view conservatives as following the policies of social Darwinism, laissez-faire, and having†¦show more content†¦Thus this contributed to Americas success and auspicious attitude towards supporting the liberal policies of laissez- affaire in the 1920s Contrarily before the Depression, there were signs that pointed to President Herbert Hoover becoming more conservative. Document A suggests that Herbert Hoover didnt want do be considered strictly laissez-faire. Document A proposes that Herbert Hoover wanted to liberalism to be found not in striving to spread bureaucracy but striving to set its bounds, but also wanted The United States to know that, he doesnt want to be misinterpreted as believing that the Untied States ins a free for all, or system of laissez-faire. Hoover appeared as if he was less determined to preserve the capitalistic society of the 1920s seeing that he argued that capitalism also has social obligations. However, the success of the American economy under presidents Hading and Coolidge who believed in private interest beliefs required him to make sure that the lack of intervention in the economy would be maintained. Also Hoover began to sense of the public disapproval and transformation of the working masses and public views. The public mass began to start looking favorably on restriction of unfair business practices. This transformation of the public opinion gave president Hoover trouble since he wasnt completely dedicated to the private interest or public purpose.Show MoreRelatedEssay on Hoover vs. Roosevelt629 Words   |  3 PagesMatt Stefanko APUS – Period 7 8 April 2010 Hoover vs. Roosevelt Herbert Hoover and Franklin Roosevelt were both presidents during one of the most difficult times in American history, the Great Depression. To try and ease the hardships that many Americans were facing, each President developed many different programs. 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