Date post: | 13-Apr-2015 |
Category: |
Documents |
Upload: | piyush-agnihotri |
View: | 829 times |
Download: | 31 times |
SPEED CONTROL OF DC MOTOR USING TRIAC
Submitted By :- Ankit Patel
Branch :- EN-3rd Year
Guided by :- Assistant professor:-Mr. Sanjay Kumar
Outline
Background Formulae Methods of speed control TRIAC Circuit Symbol Components used Advantages Disadvantages
INTRODUCTION
DC motors are widely used in industry because of its low cost, less complex control structure and wide range of speed and torque
With the the increasing use of power semicondutor units, the speed control of DC motor is increasingly getting sophisticated and precise.
Formulae
METHODS OF SPEED CONTROL
Practically, speed control of DC motors can be fulfilled using on of two methods Field Control :- by varying the field current. This can be achieved by varying the field voltage. Voltage control :- by varying the armature terminal voltage.
TRIACA triac is a bidirectional thyristor with
three terminals
Its three terminals are designated as MT1(main terminal 1),MT2 & gate by G
Triac can be turned on in each half cycle of the applied voltage by applying a positive or negative voltage to the gate w.r.t terminal MT1
To successfully trigger a triac,gate current must come from the main terminal 2(MT2) side of the circuit
CIRCUIT SYMBOL
BT136
Block Diagram of Speed Contol of DC Motor
D.C.Motor
TRIAC D.C. Supply
COMPONENTS
Dc motor Triac Diac Capacitors- C1 , C2 , C3 , C4-.1F Resistors- R1-180,R2-68, R3-47K,Pot-220k
Description
Waveform
ADVANTAGES……
In earlier days speed of the dc motor was controlled using resistor which resulted in power loss but introduction of triac eliminated the power loss
Armature voltage control method gives good speed regulation and high efficiency
Gives a large speed range with any desired number of speed points
Disadvantages..…..
Today Introduction of IGBT made the speed control of dc motor more feasible
Commutation circuit used in the circuit makes speed control less precise
Thank you!