electrical engineering

<div dir="ltr" style="text-align: left;" trbidi="on"><div class="MsoNormal" style="color: red; margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify; text-indent: -36pt;"><span style="font-size: large;"><span style="font-family: Arial; letter-spacing: -0.1pt;">        </span><u><span style="font-family: Arial; letter-spacing: -0.1pt;">Mechanical Motion From Electrical Energy</span><span style="font-family: Arial; letter-spacing: -0.1pt;"></span></u></span></div><div class="MsoNormal" style="margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial; letter-spacing: -0.1pt;">If a current carrying wire is placed in another magnetic field, magnetic forces are produced to either attract or repel wire depending on direction of two fields.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial;">The lines of force can be compared to elastic bands, which stretch outward when a force is exerted upon them and contract when the force is removed.</span></div><div class="MsoNormal" style="margin-left: 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="color: red; margin-left: 36pt; text-align: justify;"><span style="font-size: large;"><u><span style="font-family: Arial;">Characteristics of magnetic lines of force:</span></u></span></div><div class="MsoNormal" style="margin-left: 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><span style="font-family: Arial;">a.         Magnetic lines of force pass through all materials, there is no insulator against them.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><span style="font-family: Arial;">b.         Each magnetic line forms a closed loop. Its direction is externally from the North Pole to the South Pole.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify; text-indent: 36pt;"><span style="font-family: Arial;">c.         Magnetic lines of force do not cross each other</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify; text-indent: 36pt;"><span style="font-family: Arial;">d.         Magnetic lines of force tend to shorten themselves</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="color: red; margin: 0cm 28.45pt 0.0001pt 36pt; text-align: left;"><u><span style="font-size: large;"><span style="font-family: Arial;"></span></span><span style="font-size: large;">Laws of attraction and repulsion</span></u></div><div class="MsoNormal" style="margin-left: 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><span style="font-family: Arial;">a.         Two unlike poles North and South will attract each other if brought together</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><span style="font-family: Arial;">b.         Two like poles, North and North, or South and south will repel each other if brought together. Note that lines of force traveling in the same direction cause repulsion.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><span style="font-family: Arial;">c.         The force between two magnets decreases rapidly with the distance of separation.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><span style="font-family: Arial;">d.         The rule, which relates the direction of magnetic field and conventional current flow, shown in figure 1.1, is known as the Right Hand Rule.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: justify; text-indent: -36pt;"><br />
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</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><span style="font-family: Arial;"> </span><a href="http://hayatei.blogspot.com/2010/12/mechanical-motion-from-electrical.html"><img alt="http://www12.0zz0.com/2010/12/15/08/553479626.png" src="http://www12.0zz0.com/2010/12/15/08/553479626.png" /></a></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><b><span style="font-family: Arial;">Fig.1-1.Application of the right hand rule</span></b></div><div></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><span style="font-family: Arial;">The magnetic fields around conductors interact to produce forces of attraction or repulsion as shown on <b>Fig.1-2.</b></span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><a href="http://hayatei.blogspot.com/2010/12/mechanical-motion-from-electrical.html"><img alt="http://img105.herosh.com/2010/12/15/612512520.png" src="http://img105.herosh.com/2010/12/15/612512520.png" /></a><span style="font-family: Arial;"><b> </b></span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><span style="font-family: Arial;"><b><br />
</b></span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><b><span style="font-family: Arial;">Fig.1-2.Forces of interaction between current carrying conductors</span></b></div><div style="text-align: center;"></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><br />
</div><div style="text-align: center;"></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><br />
</div><div style="text-align: center;"></div><div class="MsoBodyTextIndent" style="margin-right: 28.45pt; text-align: center;">The lines of force flowing in opposite direction produce force of attraction, while lines of force flowing in the same direction produce repulsion.</div><div style="text-align: center;"></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><br />
</div><div style="text-align: center;"></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><b><span style="font-family: Arial;">The principle of motor operation is shown in</span></b><span style="font-family: Arial;"> <b>Fig.1-3.</b></span></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><br />
</div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><a href="http://hayatei.blogspot.com/2010/12/mechanical-motion-from-electrical.html"><img alt="http://img103.herosh.com/2010/12/15/572203354.png" src="http://img103.herosh.com/2010/12/15/572203354.png" /></a><span style="font-family: Arial;"><b> </b></span></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><span style="font-family: Arial;"><b> </b></span></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"></div><div align="center" class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><b><span style="font-family: Arial;">Diagram 1.3a current is flowing in the coil thus no flux is produced and no torque is present no motion.</span></b></div><div align="center" class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><br />
</div><div align="center" class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"></div><div align="center" class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"></div><div align="center" class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><a href="http://hayatei.blogspot.com/2010/12/mechanical-motion-from-electrical.html"><img alt="http://img102.herosh.com/2010/12/15/126379707.png" src="http://img102.herosh.com/2010/12/15/126379707.png" /></a><b><span style="font-family: Arial;"> </span></b></div><div align="center" class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><b><span style="font-family: Arial;"><br />
</span></b></div><div class="MsoNormal" style="margin-left: 36pt; text-align: center;"><span style="font-family: Arial;"><b> </b></span></div><div style="text-align: center;"></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"></div><div align="center" class="Document2" style="direction: ltr; margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial;">Diagram 1.3b Current is passing through the coil, the flux produced causes repulsion force (same direction of lines of force). The coil rotates.</span></b></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><a href="http://hayatei.blogspot.com/2010/12/mechanical-motion-from-electrical.html"><img alt="http://img105.herosh.com/2010/12/15/923467887.png" src="http://img105.herosh.com/2010/12/15/923467887.png" /></a><span style="font-family: Arial;"> </span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"><span style="font-family: Arial;"> </span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 108pt; text-align: center; text-indent: -36pt;"></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><b><span style="font-family: Arial;">Diagram 1.3c No torque since the coil is not being pushed from or propelled out of the field. No cutting of lines of force.</span></b></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><a href="http://hayatei.blogspot.com/2010/12/mechanical-motion-from-electrical.html"><img alt="http://img105.herosh.com/2010/12/15/706426291.png" src="http://img105.herosh.com/2010/12/15/706426291.png" /></a><b><span style="font-family: Arial;"> </span></b></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"><b><span style="font-family: Arial;"><br />
</span></b></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: center;"></div><h2 style="text-align: center;"><span style="font-size: small;">Fig.1-3d.The motor principle</span><span style="font-size: small;"><span style="font-family: Arial;"> </span></span><span style="font-size: small;"><span style="font-family: Univers;"> </span></span></h2><h2 style="text-align: center;"><span style="font-size: small;"><span style="font-family: Univers;">Diagram 1.3d the coil is rotated by 180 </span><span style="font-family: Symbol;">°</span><span style="font-family: Univers;"> from original position, for the motor to </span></span></h2><h2 style="text-align: center;"></h2><div class="MsoBodyText" style="text-align: center;">continue to rotate in the same direction; the supply voltage must be reversed.</div><div></div><div class="Document2" style="direction: ltr; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial;">An AC supply or a commentator can do this.</span></b></div><h2 style="text-align: center;"><span style="font-size: small;"><span style="font-family: Univers;"> </span></span></h2><div></div><div style="text-align: center;"><br />
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Mechanical Motion From Electrical Energy

Mechanical Motion From Electrical Energy If a current carrying wire is placed in another magnetic field, magnetic forces are produced to either attract or repel wire depending on direction of …

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<div class="MsoNormal" style="margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify; text-indent: -36pt;"><b><span style="font-family: Arial; letter-spacing: -0.15pt;">1.0</span></b><b><span style="font-family: Arial; font-size: 12pt; letter-spacing: -0.15pt;">       </span></b><b><u><span style="font-family: Arial; letter-spacing: -0.15pt;">INTRODUCTION</span></u></b><u><span style="font-family: Arial; font-size: 12pt; letter-spacing: -0.15pt;"></span></u></div><div class="MsoNormal" style="margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial; letter-spacing: -0.1pt;">A motor is a device, which converts electrical energy into mechanical energy. The modern power station requires a wide range of electric motors ranging from small fractional power to motors as large as 15 MW. There are about 2,000 motors in a typical power station.</span></div><div class="MsoNormal" style="margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify; text-indent: -36pt;"><b><span style="font-family: Arial; letter-spacing: -0.1pt;">2.0       <u>PRINCIPLES OF ELECTRIC MOTORS OPERATION</u></span></b></div><div class="MsoNormal" style="margin: 0cm 2.1pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial; letter-spacing: -0.1pt;">One of the most frequently used effects of electric current is its ability to produce force called magnetism. This force is responsible for the operation of motors, generators, measuring instruments, and communication equipment, transformers and control devices.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial; letter-spacing: -0.1pt;">Iron, nickel, and some oxides and alloys are called magnetic materials because they can be magnetized. A rough classification divides magnets into two groups; permanent and temporary magnets.</span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial; letter-spacing: -0.1pt;">A permanent magnet will keep its strength after the magnetizing force is removed. Many alloys make excellent permanent magnets as well as high carbon steels. </span></div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><br />
</div><div class="MsoNormal" style="margin: 0cm 28.45pt 0.0001pt 36pt; text-align: justify;"><span style="font-family: Arial; letter-spacing: -0.1pt;">Temporary magnets become strongly magnetized when placed inside current carrying coil. These electromagnets have a much wider use and a greater variety of applications than permanent magnets. The material used most frequently for electromagnets is the soft alloy silicon iron. This alloy is used in transformers, motors, and generators, relays, and other electromagnetic equipment. </span></div></div>

INTRODUCTION TO MOTORS

1.0 INTRODUCTION A motor is a device, which converts electrical energy into mechanical energy. The modern power station requires a wide range of electric motors ranging from small fractional po…

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