Speed Control of Dc Motor by Pulse Width Modulation(Pulse Width Modulation)-Goutam Padhy
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Transcript of Speed Control of Dc Motor by Pulse Width Modulation(Pulse Width Modulation)-Goutam Padhy
SPEED CONTROL OF DC MOTOR
BY PULSE WIDTH MODULATION
ALL RIGHTS ARE BEING RESERVED TO GOUTAM PADHY
COPY RIGHT PROTECTED@GOUTAM PADHY
FOR MORE DETAILS CONTACT:
Phone number:+918093611841(self)
+918093541377
EMAIL:
by
Goutam padhy Roll # 201018162
My project is speed control of dc motor by pulse width
modulation.its true that there are many methords of
controlling the dc motor but I have choosen the most
economic way to control the speed of dc motor.in this I
have used two ic 1.555 timer ic and 2.l293d ic the work
of 555 ic is to generate pulse and the l293d ic works as
motor driving ic,this helps to drive the motor in this
project I did all the things in a very economic way and
with the help of these two ic and some resisters,I have
controlled the speed od dc motor by pulse width
modulation.
1.abrastract
2.acknowledgement
3.introduction
4.descreption of different features.
5.circuit diagram
6.working principle
7.operations
8.advantages
9.disadvantages
10.implimintations
11.conclusion
12.reference
1.1 Project Objective:The project given to us is the speed control of d.c motor by
pulse width modulation(pwm).in this,we control the speed of a
12 volt d.c motor by modulating the width of the pulse this is
achieved with the help of two ic
1.555 timer ic & 2.l293d motor driving ic.
1.2 Features of the Project:When a wire that carries current is placed in a region of space that has a magnetic field, the wire experiences a force.• The size of the force, which determines how fast the motor spins, depends on :o the amount of current in the wireo the length of the wire o the strength of the magnetic field• The direction of the force, which determines which direction the motor spins,depends on:o the direction of the current in the wire o the direction of the magnetic field
The Physiology of the Motor: (How does it work?)
The ceramic bar magnet provides the magnetic field in this simple DC motor.With the magnet in position, the magnetic field is directed vertically (out of or into the magnet depending on which side of the magnet is exposed).When the rotor sits in the paperclip supports so that the plane of the loop isoriented vertically, the top and bottom sections of the loop act as current carrying wires in the region of a magnetic field.Q: Why only the top and bottom sections? Doesn’t the rest of the loop matter?A: Only the sections of wire oriented perpendicularly to the magnetic field experience forces. Since the magnetic field is oriented vertically here, only the sections of wire where the current runs horizontally matter (experience forces). The current only runs horizontally in the top and bottom sections of the loop. Clockwise Current Counterclockwise CurrentTop = current travels right Top = current travels leftBottom = current travels left Bottom = current travels rightOne loop of wire carrying current in the region of a magnetic field would experience a force. Two loops of wire carrying a similar current would experience twice the force. If the rotor contains 12-15 loops of wire, it experiences 12-15 times the force of one loop.
Q:What about the direction of the force? As mentioned above, the direction of theforce on a current carrying wire in a magnetic field, and thus the direction that theBar Magnet Bar MagnetBar Magnet Bar Magnet
motor turns, can be determined by the Right Hand Rule. Let’s apply the RightHand Rule to the simple DC motor.
Sorry it l293d not “33”……..i have done this with paint so got the mistake sorry.for
more details can contact me.
WORKING PRINCIPLE OF SIMPLE DC MOTOR:When a wire that carries current is placed in a region of space that has a magnetic field, the wire experiences a force.• The size of the force, which determines how fast the motor spins, depends on :o the amount of current in the wireo the length of the wire o the strength of the magnetic field• The direction of the force, which determines which direction the motor spins,depends on:o the direction of the current in the wire o the direction of the magnetic field
The Right Hand Rule is used to determine the direction of the force when the direction of the current and the direction of the magnetic field are known. Motors convert electrical energy (from a battery or voltage source) into mechanical energy (used to cause rotation). Force = (current) x (wire length) x (magnetic field)Thumb = direction of currentFingers = dir. of magnetic fieldPalm = direction of force
OPERATION OF DC MOTOR:Typical DC Motor Cutaway View1-3 Principle of Alternative Current MotorOperation Structure of AC Motor By energy the stator windings with proper AC currents, a rotating magnetic field will be generated in the air gap.Air gapRotorStator The stator is constructed by laminated iron core with slots, and the coils are placed in the slots to form a single or multi phase windings. Depending on the AC motor types, various rotor structures can be constructed,either withcurrent in the associate windings or not
ADVANTAGES OF SPEED CONTROL OF DC MOTOR BY PULSE WIDTH MODULATION:Load efficiency is almost always a critical factor in renewable energy
systems. An additional advantage of pulse width modulation is that the
pulses are at the full supply voltage and will produce more torque in a
motor by being able to overcome the internal motor resistances more
easily. A resistive speed control will present a reduced voltage to the
load, which can cause stalling in motor applications. Finally, in a PWM
circuit, common small potentiometers may be used to control a wide
variety of loads, whereas large and expensive high power
DISADVANTAGES OF SPEED CONTROL OF DC MOTOR BY PULSE WIDTH MODULATION:The main disadvantages of PWM circuits are the added complexity and the possibility of generating radio frequency interference (RFI). RFI may be minimized by locating the controller near the load, using short leads, and in some cases, using additional filtering on the power supply leads.This circuit has some RFI bypassing in the form of a capacitor (C3) across the load, and produced minimal interference with an AM radio that was located under a foot away. Radio interference was undetected at greater distances. If additional filtering is needed, a car radio line choke may be placed in series with the DC power input. Be sure not to exceed the current rating of the choke.
Using a function generator with a small motor, we can test this:This solution can also work in other situations, such as 7-segment LEDs:
Using National Instruments’ LabVIEW development software, integrate with the NI-ELVIS to produce a working function generator capable of generating square waves with a modifiable duty cycle, as well as being able to control the function generator through the LabVIEW software.
In this project I have used two ic inwhichone is 555 timer ic and another
is l293d ic which is a motor driving ic .here I have connected the cicuit
first tested on the bred board,then –found that working and then hense
have did soldering on the all purpose board,now my project is a fully
working project.hense in this way I have controlled the speed of dc motor
by pulse width modulation.
For some more details you
can contact me.
…thank u…