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Showing posts with the label disadvantages of permanent magnet moving coil instrument

LOCO SHED GOMOH

ACKNOWLEDGEMENT I would like to express my sincere grateful and profound gratitude to LOCO SHED ,GOMOH for providing an opportunity to undergo Vocational Training of 04 weeks in “ELECTRIC LOCO SHED, Gomoh, Jharkhand’’. I bear immense pleasure in expressing my gratitude and thanks to all the Employees of respective shops for their honest teaching, practical demonstration, guidance and suggestion in respective sections. Furthermore, I would like to acknowledge with much appreciation the crucial role of staffs, who gave us the permission to use all required equipment and the necessary materials during our training period. CONTENTS 1. Introduction 2. Locomotives 3. Syntaxs used in Loco 4. Components of Loco 5. Different Sections of Loco 6. Brake Rigging 7. Pantograph 8. Traction Converter 9. Working of Loco 10. Conclusion INTRODUCTION  The ISO-9001-2008 certified Electric Loco Shed, East Central Railway, Gomoh situated in Gomoh. ELECT...

Permanent Magnet Moving Coil

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Permanent Magnet Moving Coil:- *Advantages of permanent magnet moving coil instruments:- (1.) Very small power is required for its operation. Hence,  power consumption is very low. (2.) Torque to weight ratio of movie system is high. (3.) Scale is uniform and long scale is obtained. (4.) It can be used as a ammeter or voltmeter only by using external resistances. (5.) It is free from hysteresis error. (6.) Error due to stray magnetic field is negligible. (7.) Eddy current damping is used to without any extra damping mechanism. (8.) Strong operating magnetic field due to permanent magnet and iron core arrangement. * Disadvantages of permanent magnet moving coil instruments:- (1.) With time the strength of permanent magnets reduces, causing error in reading. (2.) Thermoelectric e.m.f may cause errors when it is used with shunts. (3.) Costly. (4.) Can be used on D.C only and not on A.C. This is because the direction of magnetic field due to permanent magnet is fixed. And if the direct...