sequential timer for dc motor control

7/25/2019 Sequential Timer for DC Motor Control

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PROJECT PRESENTED BY:-

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I WOULD LIKE TO GIVE MY SPECIALTHANKS TO SIR. MR ARVIND MISHAL, FOR HELPING

AND GUIDING US IN MAKING THIS MINI PROJECT.

THE TOPIC OF MINI PROJECT SPEED

CONTROL OF D.C. MOTOR USING PWM METHODWAS TAKEN BY OUR GROUP MEMBERS IN GUIDANCEOF SIR. ARVIND MISHAL ,SO WE HAVE HEREBYCOMPLETED OUR MINI PROJECT SUCCESSFULLYAND HOPE OUR PROJECT IS MADE AS REQUIRED BYTHE ELECTRICAL AND ELECTRONIC WORKSHOPSUBJET IN SEMESTER OF DEGREE ELECTRICAL!GTU".

WE ALSO THANKS ALL OURSUPPORTING

MEMBERS ,WHO EVER GET INDULGED IN MAKINGOUT NEW IDEAS AND TECHNIQUES RELATED TO THEPROJECT. THUS HEREBY WE THANK ALMIGHTY INORDER OF COMPLETING THIS MINI PROJECT ASREQUIRED.

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ABSTRACTThe aim of development of this project is towards providing efficient

and simple method for control speed of DC motor using pulse width

modulation technique. The modulation of pulse width is obtained

using cd4010b Schmitt trigger and rectifier 1n4140.

There are several methods for controlling the speedof DC motors. ne simple method is to add series resistance using

a rheostat. !s considerable power is consumed in the rheostat" this

method is not economical. !nother method is to use a series switch

that can be closed or opened rapidl#. This t#pe of control is termed

as chopper control. The $%& based chopper circuit smoothl#

controls the speed of general purpose DC motors.

To get desired modulation of pulse width as

output" we have used Schmitt trigger cd4010'b and rectifier

1n4010b with regulator as the source of var#ing output.

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TABLE OF CONTENTS

ACKNOWLEDGEMENT....................................Error! Bookmark not defned.

ABSTRACT

iiii

TABLE OF CONTENTS...................................Error! Bookmark not defned.

GLOSSARY OF TERMS......................................................................v

1. INTRODUCTION TO PWM TECHNIQUE

1.1 GOAL...........................................................................................1.2 PULSE WIDTH MODULATION PWM BASI"S.................................

2. THEORY

2.1 "OMPONENTS IN MINI P#O$E"T.................................................2.2 GOAL"D%&1&'B

((((((((((((((((((((((((((((((((((((((

(((( 122.)

INT#ODU"TION((((((((((((((((((((((((((((((((((((((((.12

2.%

I*EATU#ES((((((((((((((((((((((((((((((((((((((((((( 12

2.+

DIAG#AM((((((((((((((((((((((((((((((((((((((((((1)

2.' #EGULA#"D%&1&'B((((((((((((((((((((((((((((((((( 1%

2.,

APPLI"ATION(((((((((((((((((((((((((((((((((((((1%

2.- GOAL1N%1%-((((((((((((((((((((((((((((((((.1'

2. INT#ODU"TION.................................................................1'

2.1& *EATU#ES........................................................1'

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2.11 #EGULA#1N%1%-...................................................1,2.12 APPLI"ATION......................................................................1,

3. CIRCUIT DESIGN

).1 "I#"UIT DESIGN O* MINI P#O$E"T....................Error! Bookmark

not defned.

4. CIRCUIT DESCRIPTION AND WORKING%.1 E/PLANATION............................................................................%.2 GOALPWM

(((((((((((((((((((((((((((((((((((.2&%.) BLO"0 DIAG#AM O*

PWM((((((((((((((((((((..2&Error! Bookmark o

"#$%#".

&. CONC'UTION

+.1 GOAL.........................................................................................+.2 "ON"LUSION.............................................................................

(. )UTURE MODI)ICATIONS

'.1 GOAL.........................................................................................'.2 POSSIBLE MODI*I"ATIONS.........................................................

GLOSSARY OF TERMS

AC - Alternating Current

NPT - Non Punch Through

C - Cathode a" #cillo#co$e

%C - %irect Current

&C - &ntegrated Circuit

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P'( - Pul#e 'idth (odulation

VR -V#$%&'( R(')$&%#*

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1.

INTRODUCTION

TO PWM TECHNIQUE

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+.+ GOAL

T# ($&/ PULSE WIDTH MODULATION %(01/2)( / 3*(4.

+.5 P)$6( W7%1 M#7)$&%#/ !PWM" B&606

There are man# forms of modulation used for communicating

information. %hen a high frequenc# signal has amplitude varied in response toa lower frequenc# signal we have !& (amplitude modulation). %hen the signalfrequenc# is varied in response to the modulating signal we have *&(frequenc# modulation. These signals are used for radio modulation becausethe high frequenc# carrier signal is needs for efficient radiation of the signal.

%hen communication b# pulses was introduced" the amplitude" frequenc# andpulse width become possible modulation options. +n man# power electronicconverters where the output voltage can be one of two values the onl# option ismodulation of average conduction time.

Fig. 1.1 Unmodulated, sine modulated pulses

1. Linear Modulation

The simplest modulation to interpret is where the average ,time of the pulses varies proportionall# with the modulating signal. Theadvantage of linear processing for this application lies in the ease of de-modulation. The modulating signal can be recovered from the $%& b# lowpass filtering. *or a single low frequenc# sine wave as modulating signalmodulating the width of a fied frequenc# (fs) pulse train the spectra is asshown in *ig 1./. Clearl# a low pass filter can etract the modulating

component fm.

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Fig. 1.2 Spectra of PW

2. Sawtooth PWM

The simplest analog form of generating fied frequenc# $%& isb# comparison with a linear slope waveform such as a saw tooth. !s seen in*ig 1./ the output signal goes high when the sine wave is higher than the sawtooth. This is implemented using a comparitor whose output voltage goes tologic + when ne input is greater than the other. ther signals with straightedges can be used for modulation a rising ramp carrier will generate $%& withTrailing 2dge &odulation.

Fig. 1.! Sine Sa"toot# PW

+t is easier to have an integrator with a reset to generate the rampin *ig1.4 but the modulation is inferior to double edge modulation.

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Fig.

1.$

Trailing %dge odulation

3. Regular Sampled PWM

The scheme illustrated above generates a switching edge at theinstant of crossing of the sine wave and the triangle. This is an eas# scheme toimplement using analog electronics but suffers the imprecision and drift of allanalog computation as well as having difficulties of generating multiple edgeswhen the signal has even a small added noise. &an# modulators are nowimplemented digitall# but there is difficult# is computing the precise intercept ofthe modulating wave and the carrier. 3egular sampled $%& maes the widthof the pulse proportional to the value of the modulating signal at the beginningof the carrier period. +n *ig 1.5 the intercept of the sample values with thetriangle determine the edges of the $ulses. *or a saw tooth wave of frequenc#fs the samples are at /fs.

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Fig. 1.& Regular Sampled PW

There are man# wa#s to generate a $ulse %idth &odulatedsignal other than fied frequenc# sine sawtooth. *or three phase s#stems themodulation of a 6oltage Source +nverter can generate a $%& signal for eachphase leg b# comparison of the desired output voltage waveform for eachphase with the same sawtooth. ne alternative which is easier to implement ina computer and gives a larger modulation depth is using space vectormodulation.

4. Modulation Depth

Fig. 1.'

Saturated

Pulse

Widt#odulation

*or a single phase inverter modulated b# a sine-sawtoothcomparison" if we compare a sine wave of magnitude from -/ to 7/ with atriangle from -1 to 71 the linear relation between the input signal and theaverage output signal will be lost. nce the sine wave reaches the pea of thetransgle the pulses will be of maimum width and the modulation will thensaturate. The &odulation depth is the ratio of the current signal to the casewhen saturation is just starting. Thus sine wave of pea 1./ compared with a

triangle with pea /.0 will have a modulation depth of m80.'.

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2.

THER!

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5.+

C&$,2,TS 9S2D +, &+,+ $3:2CT

;S$22D C,T3< * D.C. &T3

9S+, $%& &2TD=

"#TTER!

$#P#$%TR

R%#"LE RE'(L#TR

H%'H SPEED D%DE 1)414*

S$HM%TT TR%''ER $D4*1*+"

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RES%STR

MTR

#MPL%,%ER TR#)S%STR

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IN)ORMATION

ON

S*+m% r%,,#r CD-1(B

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5.5 GOAL

T# 6%)78 &3#)% S019%% %*''(* CD+;B &/7 %6 4)/0%#/ / %1(

0*0)%.

5. t#pes are supplied in 14 lead hermetic dual-in-line ceramicpacages (D and * suffies)"14-lead dual-in-line plastic pacage(2 suffi)"

and in chip form ( suffi).

2.4 ,eature-

Schmitt-trigger action with no eternal components

#steresis voltage(t#p.) 0.?6 at 6DD856" /.@6 at 6DD8106" and @.56at 6DD8156

,oise immunit# greater than 50A

,o limit on input rise and fall times

StandardiBed" s#mmetrical output characteristics

100A tested for quiescent current at /06

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&aimum input current of 1m! at 16 over full pacage-temperature

range100n! at 16 and/5EC


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F'.L#'0 7&'*&9 !+ #4 ; S019%% %*''(*6"

5.; REGULAR CD+;B

CD+;B SCHMITT TRIGGERBY TE?AS INSTRUMENTS

5.@ A$0&%#/6

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%ave and pulse shapers

igh-noise-environment s#stems

&onostable multivibrators

!stable multivibrators

INTRODUCTION

ON

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H'1 6((7 7#7(

+N+

5. GOAL

;To stud# about high speed diode 1,414=

5. INTRODUCTION

The 1,414 is a standard siliconswitching diode.

+t is one of the most popular and long-lived switching diodes

because of its dependable specifications and low cost.

+ts name follows the :2D2Cnomenclature.

The 1,414 is useful in switching applications up to about

100 &B with a reverse-recover# timeof no more than 4 ns.

The 1,414 comes in a D-@5glass pacage for thru-

holemounting.

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http://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/JEDEChttp://en.wikipedia.org/wiki/Diode#Reverse-recovery_effecthttp://en.wikipedia.org/wiki/DO-35http://en.wikipedia.org/wiki/Through-hole_technologyhttp://en.wikipedia.org/wiki/Through-hole_technologyhttp://en.wikipedia.org/wiki/Siliconhttp://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/JEDEChttp://en.wikipedia.org/wiki/Diode#Reverse-recovery_effecthttp://en.wikipedia.org/wiki/DO-35http://en.wikipedia.org/wiki/Through-hole_technologyhttp://en.wikipedia.org/wiki/Through-hole_technology


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This is useful for breadboardingof circuits. ! surface

mountdevice" 1,414%S" is available in aplastic SDpacage.

5.+ FEATURES

H(*9(%0&$$8 6(&$(7 $(&7(7 '$&66 SOD5@ !DO-


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5.+5 APPLICATION

H'1-6((7 6%01/'.

3.

CIRCUIT DESIGN

3.1 /C%r*0% "#%, o$ ##" *oro o$ ".*.

moor4

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-.

CIRCUIT DESCRIPTION

AND WORKING23


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-.1 E5P'ANATION6

Here is a simple PWM moor ##" *oro#r circuit

that can be used for varying the speed of lo poer !"motors #

$he variation in speed is achieved by varying the duty

cycle of the pulse supplied to drive the motor#

%f the to gates of &" "!40106' ( )1 is ired as an

inverting *chmitt $rigger astable multi vibrator forproducing pulses and )2 as an inverting buffer to drive

the transistor during positive cycles at base#

$he duty cycle is set from resistor +2#

+1 limits the base current of transistor *, 100# $he circuit

is ideal for controlling toy motors(hand held mini fans (

small bloers etc#

.5 GOAL

T# ($&/ #*/' #4 %1( PWM 0*0)%.

4.3 "#S%$ "L$ D%#'R#M

!s shown in bloc diagram there are mainl# three blocsF !stable&ultivibrator" &onostable &ultivibrator and Driving Circuit.

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http://www.circuitstoday.com/pwm-motor-speed-controllerhttp://www.circuitstoday.com/pwm-motor-speed-controller


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Fig. $.1 Bloc( )iagram

T1( B&60 B$#06 &*( ($&/(7 3($#:

#-ta/le Multi0i/rator This bloc produce square pulses of same frequenc#

according to time constant RC. These pulses are fed to net bloc as triggeringpulses.

Mono-ta/le Multi0i/rator This bloc produces square pulses of variable

frequencies. The frequenc# of output pulse can be varied b# changing thevalue of resistor shown in figure. These pulses are fed to the driving circuit.

Dri0ing $iruitThis bloc provides power required to drive the motor. !s the

frequenc# of output pulses of &onostable multivibrator changes" the averagevoltage supplied to motor changes. ence" the speed of motor changes.

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&.

CONC'USION

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=.+ GOAL

T# 0#/0$)7( %1( #* 0&**(7 #)%.

=.5 CONCLUSION

*rom the project wor" following points can be concluded.

+. +t fulfils all the requirements for its application.

5. The motor responds to the average value of the pulses and not to the

individual pulses as the chopper wors at high frequenc#.


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(.

)UTUREMODI)ICATIONS

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;.+ GOAL

T# 1'1$'1% #663$( 9#740&%#/6 %1&% 0&/ 3( 9&7( / %1(

*#(0% 4#* 9*#>/' (*4#*9&/0(.

;.5 POSSIBLE MODIFICATIONS

Following are the possible future modifications in our project work.

TAB)E *+-* ,TE (%&,&CAT&N

S*.

N#.

M#740&%#/ P)*#6(

1 9se of micro-

controllerGmicro-processor

for closed loop operation

Constant speed variation

/ 9se of &S*2T or +>T igher voltage and power requirement

sequential timer for dc motor control

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