4 – DC Machine 1. Describe operation of DC machine (motor and generator) using illustrations. Specifically explain the purpose of: a. brushes d. armature winding b. split ring commutators e. effect of back emf (in operation) c. field winding 2. Draw the different configurations of DC machines a. shunt c. separately excited b. series 3. Develop‚ using Kirchhoff’s laws‚ equation for Ea (armature voltage) in both motoring and generating mode. 4. Describe three (3) methods of speed control in DC machines
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A DC motor is a mechanically commutated electric motor powered from direct current (DC). The stator is stationary in space by definition and therefore so is its current. The current in the rotor is switched by the commutator to also be stationary in space. This is how the relative angle between the stator and rotor magnetic flux is maintained near 90 degrees‚ which generates the maximum torque. DC motors have a rotating armature winding but non-rotating armature magnetic field and a static field
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DC to AC Inverter Assignment # 2/ Spring 2013 CE721 Ahmad Ghaffari‚ 1203840 Submit Date: Tuesday 19‚ 2013 Abstract DC-AC inverter is a device that converts a direct current (DC) into an alternating current (AC). When there is no AC main power for applications in caravans‚ remote area and etc.‚ this tool is very suitable to use. It mainly converts a DC source (like a car’s battery) to an AC source (230V) to use for power application like
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Maurice Aguirre Washington DC: Lobbying active in the United States Lobbying in America refers to paid activity on which distinctive interests retain the services of well-connected experienced advocates‚ typically lawyers‚ to argue for focused regulations in decision making bodies for example the United States Congress. It’s just a highly provocative phenomenon‚ usually seen in a negative light by reporters and the US public. Even while lobbying is certainly theme to thorough plus typically
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| | | | | | | DC Motors | | | | | | | | | | | | | The direct current (DC) motor is one of the first machines devised to convert electrical power into mechanical power. Permanent magnet (PM) direct current converts electrical energy into mechanical energy through the interaction of two magnetic fields. One field is produced by a permanent magnet assembly; the other field is produced by an electrical current flowing in the motor windings. These two fields result in a torque
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of them are easily recognizable as the United States capital city. II. Washington D.C. is the second most visited city I the United States. Also it is a good place to visit. III. Today‚ I will persuade my audience about Washington D.C. also I will provide the history about it. A. The city is mainly based on government and everything from museums to mansion brings millions of tourists each year. B. Washington has a growing‚ diversified economy of professional and business service jobs
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Electrical Machines Electrical Machine Stationary Transformer Rotating DC AC Motor Induction Generator Motor Generator Synchronous Motor Generator Electrical Generator / Motors An electric generator converts mechanical energy into electrical energy. An electric motor converts electrical energy into mechanical energy. Mechanical Input Electrical input ELECTRICAL MACHINES Generator ELECTRICAL MACHINES Motor Electrical Output Mechanical output
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Types of DC Motors and DC Generators MOTORS – convert electrical energy to mechanical energy Motors and generators are the most frequent used electrical machines. ❖ Generators action can take place when and only when‚ there is a relative motion between conducting wires and magnetic lines of force. ❖ Electric motor is in operation when it is supplied with electrical energy and develops torque‚ that is‚ a tendency to produce rotation. ❖ In DC generator‚ the armature winding is mechanically
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This summer‚ I had the opportunity to go to Washington D.C. and New York with the music‚ speech‚ and drama kids. In order to go‚ you had to be in at least four activities related to band or speech. I was involved in band‚ the play‚ large group speech‚ and individual speech. After a long and dreadful sophomore year‚ I finally made it. I had a fun summer and the twilight of it was the trip‚ and it was quite satisfying. We got up early and left on a bus from George to Sioux Falls in the early morning
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connected to the alternate voltage supply. 5. The direction of DC motor was tested and determined. 6. All switches were in closed position at initial condition. 7. Only switch 1 and 4 was closed at the first condition as in figure 2(a). The direction of DC motor and the RPM of DC motor was recorded 8. Switch 1 was opened and switch 2 was closed as in figure 2(b) after the first reading was recorded. The motor was braked. The RPM of DC motor was recorded. 9. Step 7 was repeated by switching the switch
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