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The Dc Motor Speed Control Methods Engineering Essay

ABSTRACT This paper describes the Matlab and simulink converts into actuality of the DC motor speed control methods, namely field resistance, armature resistance control methods and armature voltage, and feedback control system for DC motor drives and this paper describes mathematical modelling, simulation of DC motor system using computer simulations Matlab and simulink, by this system response to change various parameters like system stability, disturbances, analysis and optimization of model parameters with respect to the quality of control. If simulation techniques are used for determining the control parameters a simulation model is necessary, which has to be constructed from the analytical model. INTRODUCTION DC Motor is an electrical motor and it most commonly used in an electrical device for easy to drive the instruments, steel rolling mills, electric cranes, and robotic manipulators due to precise, wide, simple, and continuous control characteristics. To control the speed of low power DC Motor rheostatic armature control method were used. The basic parts of the DC motor are- axle, rotor (armature), stator, commutator, field magnet, and brushes. In the geometry of brushes, commutator contacts, and rotor windings are arranged in such a manner so that when power is applied then polarities of the energized winding and the stator magnets are misaligned and the rotor will start to rotate until it is almost aligned with the stator’s field magnets. When the rotor reaches to alignment, the brushes move to next commutator contacts, and energize the next winding. There are variable types of DC Motor available in market with the good and bad qualities. Bad quality means lag in efficiency. To recover or stop this kind efficiency problem controller is introduce in the system. Brushed DC motors are most widely used in applications and its ranging from toys to push-button adjustable car seats. Brushed DC (BDC) motors are inexpensive but easy to drive. Brushed DC motors are easily available in all size and shape with the wide range from large-scale industrial models to small motors for light applications (such as 12 V DC motors). . BDC motors are most commonly used in easy to drive, with variable speed and high start-up torque applications. OBJECTIVE The Fig.1 shows the analogues electrical circuit. MODELLING The circuit which was given is drawn in the Matlab by using simulink. In the circuit diagram the flow of current BLOCK DIAGRAM Figure shows the block diagram of DC motor TRANSFER FUNCTION K/{(Ls R)(Js f) K2} ± 1/s Vapp Fig 4.1. Transfer Function STATE SPACE MODEL As we know that, V- .…. (1) ….. (2) Substituting equation (2) in (1) ……. (3) ….… (4) ……. (5) Substituting (5) in (4) – ……… (6) Differentiating (6), we get ……….. (7) Putting (3) in (7), we get ……… (8) Now ………… (9) Substituting (9) in (8), we get We know that x=Ax Bu Y=Cx Du X= The State Space Model represents by the linear equation and it is written as. x= Ax Bu y = Cx Du Below figure shows the state space model (Calculation is in appendix) Figure 5.1 State Space Model PHYSICAL SYSTEM Consider a DC Motor, in this electrical circuit of the armature and free body diagram of rotor are shown in figure below. http://zone.ni.com/cms/images/devzone/tut/mpm-2-motor1.gif Fixture: – DC Motor is a common actuator in control systems. Brushed DC Motor fundamentals A Brushed DC Motor consists of stationary fixed permanent magnets i.e. stator, a rotating electromagnetic i.e. rotor and flux, which is concentrated by metal. Rotor rotate by the attraction of the opposite poles and repulsion of the like poles, it cause to generate torque and torque acts on rotor and then make it turn. As the rotor start to rotate or turn then fixed brushes make and breaks the contact in such a way that with the rotating segments (commutation). The rotor coil of the brushed motor energized and de-energized in such a way so that the rotor start to turns. By transferring the power to the motor, current generate in rotor coils and therefore the north and south poles are reversed and because of the motor change the direction. From the Strength of the magnetic field, speed and torque of the motor depend Figure (1) Brushed DC Motor PRINCIPLE OPERATION Construction and operation of the Brushed DC Motor is shown below in figure (2).for the construction of the BDC motor always the same components are required i.e. Stator, rotor, commutator and brush. Figure (2) Simple two-pole brushed DC Motor Stator The rotor surrounded by the stationary magnetic field which is generated by the stator and this filed is generated by the permanent magnet or electromagnetic winding. On the construction of the stator, different types of BDC distinguish. Rotor Rotor is also known as an armature and it is made up of one or more windings. Magnetic field is produce when they energized. When the opposite pole of the magnetic poles, attract to each other which is generated by the stator, and causing the rotor to turns. The opposite poles are always attracting to each other. As the motor turns, the windings are being constantly energized. This deviation of the field in the rotor is called as an armature. Brushes and commutator There is no requirement of controller in BDC to switch current in motor winding. The commutation winding of the BDC motor is done mechanically. Reside on the axel of rotor there is a segmented copper sleeves called commutator. Carbon brushes slides over the commutator coming in a contact with the different segments of the commutator as the motor starts to turn. When the voltage is applied across the brushes of the motor then dynamic magnetic field is generated inside the motor. Brushes and commutator are the most important parts of the BDC motor that are most prone to wear because they are the sliding part to each other. SPEED CONTROL The Speed of a DC Motor is directly proportional to the voltage. By using the digital controller voltage can be control and to generate the average voltage pulse-width modulated (PWM) signal is used. In motor there is a motor winding which acts as a low pass filter so PWM develop a suitable current in the motor winding. ADVANTAGES Cheap in price because low cost of construction. Extend a life by replacing a brush. Inexpensive motor and simple control. Speed/Torque is normal at high speed. On fixed speed no control is required, Controller is required only at variable speed in this condition same controller can be used. DISADVANTAGES Maintenance is required for brushed DC Motor because of brush. If the brush friction increases, reduce the useful torque. Heat dissipation is poor because of internal rotor construction. Speed range is limited because of the mechanical limitation on brushes. Life is also shorter. Noise is generated due to brush. Application examples: moving toys, fans, printers, robots, electric bikes, -doors, -windows, -sun roofs, -seats, mixers, food processors, can openers, blenders, vacuum cleaners, toothbrushes, razors, coffee grinders, etc. Physical Parameters Moment of inertia of the motor (J) = 9.89 E-7 kg Nm s/rad Damping ratio of the mechanical system (b) = 5.84E-7 Nm s/rad Electromotive force or motor constant (K=Ke=Kt) = 0.008 Nm/-w Electric resistance (R) = 0.80 ohms Electric inductance (L) = 0.00041H Friction coefficient, f Input (V): Source Voltage Output (theta): position of shaft the rotor and shaft are assumed to be rigid CONCLUSION Brushed DC motors are very simple to use and easy to control, which makes them a short design-in item. PIC microcontrollers, especially those with CCP or ECCP modules are ideally suited for driving BDC motors. Refference Circuit Diagram for DC Motor Control by A. Collins http://www.nxp.com/documents/application_note/AN10513.pdf http://ww1.microchip.com/downloads/en/AppNotes/00905a.pdf http://www.orientalmotor.com/MotionControl101/AC-brushless-brushed-motors.html http://ww1.microchip.com/downloads/en/AppNotes/00885a.pdf http://www.dynetic.com/brushless vs brushed.htm file:///D:/matlab/index.php.htm
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Compensation Strategy for Knowledge Workers
To prepare for this assignment, review Waring’s article about employee compensation, Note: both links contain the same information; only one needs to be reviewed.
Waring, D. (2013). How to design an employee compensation plan [SlideShare slides]. Retrieved from http://www.slideshare.net/FitSmallBusiness/how-to-design-a-compensation-plan-dave?ref=http://fitsmallbusiness.com/how-to-pay-employees/
Waring, D. (2013). How to pay employees – The ultimate guide. Retrieved from http://fitsmallbusiness.com/how-to-pay-employees/
You are the director of compensation for a midsized organization. Prepare a PowerPoint presentation that justifies the implementation of a new compensation strategy that will support the motivational needs of knowledge workers and reinforce the real-time performance appraisal system that the organization has embraced. While your goal is to retain, motivate, and grow the current workforce of multi-generational knowledge workers, you must also justify to your senior management that this compensation strategy is competitive in the marketplace.
Your presentation should describe a compensation program for knowledge workers. The title of the knowledge worker’s position is entirely up to you (e.g., sales executive I, systems engineer III, etc.). You may use various sources (including the lesson materials), but you must use at least one additional resource from the CSU Online Library. Include a reference slide, and cite any sources used in proper APA format. Your presentation should be a minimum of 12 slides in length—not counting the title and reference slides. You may also use the slide notes function to explain slide contents as necessary, but this is not required.
Be sure to address the questions below in your presentation.

What is the compensation strategy being proposed?
Did employees provide input?
Who else provided input?
What incentives are included in the plan? How will it motivate the employees?
How will employees determine fairness of the pay structure?
Why do you believe the employees will be satisfied with this plan? Justify the compensation strategy that supports the motivational needs of knowledge workers.
What is your communication plan for rolling out the new program?

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Arizona State University Explanatory and Normative Framework Questions

Arizona State University Explanatory and Normative Framework Questions.

I’m working on a political science multi-part question and need a sample draft to help me study.

hint: the pages of the answers will be in the original worksheet that I will give youQ1. Explain the logic of the explanatory and normative framework in each of the quadrants in Figure 1. Top-left (National/National) – Top-right (National/Global) – Bottom-left (Global/National) – Bottom-right (Global/Global) – 2. What are some of the policies typically associated with the Washington Consensus? 3. Where (in what quadrant) does the Washington Consensus belong in Gore’s matrix? Explain. 4. What does Gore mean by “a shift from historicism to ahistorical performance assessment”? Explain or give examples. 5. Figure 3 and Gore’s text imply that the new paradigm may very well emerge in the Global/Global quadrant. What scenarios or policies do you imagine fit in that framework, or alternatively, are there global trends or practices in our present time that indicate this change or potential future(s)?Q2 . How is land titling supposed to work? In other words, how is it that receiving a title to one’s land or holdings (however modest) is expected to create economic growth? 2. What might be some of the barriers to land titling? Are there any stakeholders or adverse interests who would object to this approach? explain 3. What are some of the unforeseen issues or adverse effects that might arise from applying a land titling policy to an area? 4. Why do you think de Soto’s approach is so popular among mainstream politicians or conventional liberal economists? 5. What are your thoughts on de Soto’s approach? Do you find yourself agreeing more with Nordlinger, Gravois, neither, a mix, unsure? Explain.Q3 What is the logic of microlending? Put another way, how are relatively modest transfers expected to lift people out of poverty and boost economic growth?2. Microlending appears to be most successful when its loan recipients are from a particular demographic. What is that demographic and why might loans to this group yield better results of repayment? (You can answer according to Yunus and/or your own speculative explanation)3. What are some weaknesses or issues that might arise from microlending? (You can think of possible issues on your own and/or do some searching for criticisms of microlending). 4. What are your thoughts on Yunus’ approach or microlending in general?
Arizona State University Explanatory and Normative Framework Questions

What is Alzheimer’s Disease?

essay help online Share this: Facebook Twitter Reddit LinkedIn WhatsApp Dwight Coleman Wendt L. Eddy In 1906 Alzheimer’s disease was discovered by Alois Alzheimer, a German neurologist. The disease was originally observed in a middle-aged woman named Auguste D. He studied and recorded her care for five years, until her eventual death in 1906. After her death, Dr. Alzheimer performed an autopsy. He discovered senile plaques and neurofibrillary tangles, which have become indicative of Alzheimer’s disease. The condition was first discussed in 1907 and named after Dr. Alzheimer in 1910. Alzheimer’s disease (AD), is a degenerative disorder that leads to memory loss and bodily functions and is the most common form of dementia. AD affects more than 5 million Americans and is one of the top ten causes of death within the United States. The disease has been grouped into two “main” forms. Familial AD, which affects people younger than 65, adding up to nearly 500,000 AD cases in the United States. The rest of AD cases are categorized as Sporadic AD, and transpire in adults ages 65 and older. The severity of AD varies, as there are many different factors, including genetics, age, even education level. Currently there is no cure for Alzheimer’s disease, however; there is promising research being conducted and early detection and treatment is available. AD is a complex illness that affects the brain tissue directly as it undergoes gradual memory degradation and the patient demonstrates behavioral changes. There are 3 stages of Alzheimer’s disease the “Early Stage” usually lasts 2-4 years and is usually when the disease is diagnosed. During this stage friends and family may have noticed a decline in the patient’s cognitive abilities. Common symptoms may include: Misplacing belongings or getting lost. Patients may even have difficulty navigating familiar surroundings. Difficulty retaining new information. Difficulty expressing thoughts and personality changes. During “Moderate Alzheimer’s” Patients will experience an increase in memory degradation and may need help performing their everyday activities. This stage lasts 2-10 years. Symptoms include: considerable memory loss. Patients may forget their personal history and have trouble recognizing family members. Trouble completing tasks, such as grocery shopping and managing their finances. Lose orientation to time and space, patients may begin to wander. “Severe Alzheimer’s” is the diseases final stage, lasting 1-3 years. The brain continues to decline and physical capabilities are severely affected. During this stage the patient is in a nursing home due to the family’s inability to effectively care for the patient. The final symptoms include: Dependence on others for personal care, such as bathing, eating, toileting Physical capabilities hindered. Patient needs help walking and may be unable to sit independently patient’s ability to swallow can be challenged Communication. Patient limited to speaking short phrases. Although, the way that Alzheimer’s disease affects the brain is drastic it is not the primary cause of death. AD causes many handicaps, like immobility and difficulty swallowing, which leads to malnutrition and pneumonia, resulting, in the patient’s death. Currently there is not a single diagnostic test for detecting Alzheimer’s disease any other forms of dementia. There is only one true way to diagnose someone with AD unfortunately it only come after death while performing an autopsy and examining the brain tissue. Instead of an autopsy the diagnostic we perform on the living consists of thorough assessments by experienced physicians to discern the absence and presence of certain symptoms. Effectively ruling out all other possibilities until Alzheimer’s is the only option left. When done thoroughly, the diagnostic can result in a highly accurate diagnosis. The diagnostic is often called the comprehensive assessment consists of the patient’s full clinical history such as past and current medical conditions, all medication prescription and over the counter, ability to perform daily activities and personality changes. Neuroimaging to look for metabolic (PET), structural (MRI, CT, etc.), or disease related changes. Lab test of blood and neuropsychological assessment which measures the patients time and space orientation, attention and recent memory. Although certain findings through the assessment may support a diagnosis of AD, as previously stated their main focus is to rule out other possibilities, strokes, head trauma or tumors. Once the tests are completed the clinical team reviews the results and creates and individualized treatment for the patient. The diagnosis, test results, and treatment plan are presented to the patient and family during a family conference. The most evident way someone with AD can benefit is financially. AD treatment is very costly and an early diagnosis would help the patient plan for the future. LTC (long term care) insurance substantially decreasing the money needed for medical costs. Early diagnosis can benefit the patient personally, everyone has a goal in his or her life, however; with the debilitating effects of AD patients may not be able reach them. An early diagnosis gives the patient an opportunity to make future plans and accomplish their goals. Most patients do not have the luxury to make such decisions before the severe symptoms appear. Alzheimer’s disease takes an emotional toll on the patient and family. It becomes increasingly difficult to watch a family member slowly deteriorate and forget the things they used to love. Early diagnosis can give the patient and family time to learn about the progression of the disease and how to prepare for their future trials. Families will have enough time to come to terms with their feeling and what is happening, this relieves some of the stress of an uncertain future and makes the patients final years more enjoyable. References “How Alzheimer’s is diagnosed?” UCIrvine, 2015, https://www.mind.uci.edu/alzheimers-disease/what-is-alzheimers/how-is-alzheimers-diagnosed/ “Alzheimer’s disease fact sheet” National Institute of Aging, August 2016, https://www.nia.nih.gov/alzheimers/publication/alzheimers-disease-fact-sheet#causes Share this: Facebook Twitter Reddit LinkedIn WhatsApp

Hospice Care Discussion

Hospice Care Discussion.

Please watch the following Youtube Video – youtube.com/watch?v=c5IBB29LhssThe video is from Hospice Learning Center and is titled “What is Hospice Care? What You Need to Know About Hospice”.Please post a discussion sharing with the class your thoughts regarding hospice care. What is hospice care? What similarities does it share with palliative care? What are the differences? Share your views/thoughts on the subject.In view of the fact that this is an election year, lots of non-information will pop up on popular search engines. For that reason, you should find credible support for your work through the use of peer-reviewed scholarly sources from MedLine, Ebsco, Proquest, and/or Google Scholar. Please use articles within the past two or three years.As I have previously stated – the topics in this course can be emotionally trying. There are times you may disagree with your classmates; you all are to be respectful to your classmates discussions and responses.**Please write a 300 to 500 word discussion post adhering to APA 7th Edition formatting guidelines.**Please use the following rubric:APA Discussion Entries RubricScore _____/50____ (5) In-text citations include necessary info in parentheses after borrowed material____ (5) References per APA ____ (5) Grammar and spelling ____ (15) Application of three or more concepts from the learned material ____ (20) for each substantive response (2 in all, 10 points each, maximum points would be 20 possible here)
Hospice Care Discussion

Employee Engagement PowerPoint Presentation

Employee Engagement PowerPoint Presentation.

I need help with a PowerPoint Employee Engagement Presentation to present to Executives.15 plus slides on a white background, pictures are okay, including notes for each slide and citations with references. Please add the following topics and more, if needed. You may also delete what you feel isn’t necessary:What is employee engagement?Why is it important for employees to be engaged?How can you improve job satisfaction? How do you get employees engaged? How can we improve employee engagement?What is the Leadership’s responsibility to employee engagement? Suggested Training Q&APlease also add a statistics page indicating the amount of employees that are engaged.
Employee Engagement PowerPoint Presentation