PROJECT REPORTSPEED CONTROL OF DC MOTOR USING PWM TECHNIQUE

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Z xux Syed Muhammad zaidi(group leader)10es60

MUHAMMAD TAHIR 10ES27 WASEEM SHOUKAT 10ES41 MUHAMMAD RASHID 10ES45 REHMAN ALI 10ES46 MUHAMMAD RIZWAN 10ES

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Introduction we want to control speed of dc motor using pulse width modulation technique.

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Pulse width modulation Pulse width modulation (PWM) is a method for binary signals generation, which has 2 signal periods (high and low). The width (W) of each pulse varies between 0 and the period (T).

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Apparatus Dc motor Potentiometer Diode 1N4007 555-TIMER Capacitor 0.01uF Capacitor 0.1uF CE-Transistor(BD-139) DC power supply(9v)5

Working of mentioned components in this project In this project we use npncommon emitter transistor having beta amplification capability. Resistances limiting the current.555-timer act as pulse generator and capacitor used for filteration purpose.

Block diagram

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Working When potentiometer nobe moved towards forward biased diode then speed of motor high because time duration of positive pulse increased and negative pulse decreased

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High speed o/p waveform

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FOR DESIRED LOW SPEED OF MOTOR

When we want to get low speed of dc motor then potentiometer nobe moved towards reverse biased diode and then time duration of negative pulse increased and positive pulse decreased1/27/2012 10

Low speed o/p waveform

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Conclusion The present project is practical one and high feasibility according to economic point of view, reliability & accuracy. It is programmable one therefore it can control various motors ranging small one to several hp motors.

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