seismic sensor final doc

8/19/2019 Seismic Sensor Final Doc

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SEISMIC SENSOR 1

CHAPTER 1

INTRODUCTION

Nalla Malla Reddy Engg. College Department of ECE


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SEISMIC SENSOR 2

INTRODUCTION

There are two bas! types of sesm! sensors" nertal sesmometers wh!h meas#re gro#nd

moton relat$e to an nertal referen!e %a s#spended mass&' and stran meters or wh!h meas#re the

moton of one pont of the gro#nd relat$e to another. Sn!e the moton of the gro#nd relat$e to an

nertal referen!e s n most !ases m#!h larger than the dfferental moton wthn a $a#lt of

reasonable dmensons' nertal sesmometers are generally more senst$e to earth(#a)e sgnals.

*owe$er' at $ery low fre(#en!es t be!omes n!reasngly dff!#lt to mantan an nertal

referen!e' and for the obser$aton of low+order free os!llatons of the Earth' tdal motons' and

(#as+stat! deformatons' stran meters may o#tperform nertal sesmometers. Stran meters are!on!ept#ally smpler than nertal sesmometers altho#gh ther te!hn!al real,aton and nstallaton

may be more dff!#lt.

-n nertal sesmometer !on$erts gro#nd moton nto an ele!tr! sgnal b#t ts propertes !annot

be des!rbed by a sngle s!ale fa!tor' s#!h as o#tp#t $olts per mllmeter of gro#nd moton. The

response of a sesmometer to gro#nd moton depends not only on the amplt#de of the gro#nd

moton %how large t s& b#t also on ts tme s!ale %how s#dden t s&. Ths s be!a#se the sesm!

mass has to be )ept n pla!e by a me!han!al or ele!tromagnet! restorng for!e. hen the gro#nd

moton s slow' the mass wll mo$e wth the rest of the nstr#ment' and the o#tp#t sgnal for a g$en

gro#nd moton wll therefore be smaller. The system s th#s a hgh+pass flter for the gro#nd

dspla!ement. Ths m#st be ta)en nto a!!o#nt when the gro#nd moton s re!onstr#!ted from the

re!orded sgnal' and s the reason why we ha$e to go to some length n ds!#ssng the dynam!

transfer propertes of sesmometers.

The dynam! beha$or of a sesmograph system wthn ts lnear range !an' l)e that of any lnear

tme+n$arant %/TI& system' be des!rbed wth the same degree of !ompleteness n fo#r dfferent

ways" by a lnear dfferental e(#aton' the /apla!e transfer f#n!ton' the !omple0 fre(#en!y

response' or the mp#lse response of the system. The frst two are #s#ally obtaned by a



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SEISMIC SENSOR

mathemat!al analyss of the phys!al system %the hardware&. The latter two are dre!tly related to

!ertan !albraton pro!ed#res and !an therefore be determned from !albraton e0perments where

the system s !onsdered as a bla!) bo0 %ths s sometmes !alled an dentf!aton pro!ed#re&.

*owe$er' sn!e all fo#r are mathemat!ally e(#$alent' we !an der$e ea!h of them ether from

)nowledge of the phys!al !omponents of the system or from a !albraton e0perment.

ra!t!ally' the mathemat!al des!rpton of a sesmometer s lmted to a !ertan bandwdth of

fre(#en!es that sho#ld at least n!l#de the bandwdth of sesm! sgnals. thn ths lmt then any

of the fo#r representatons des!rbe the system3s response to arbtrary np#t sgnals !ompletely and

#nambg#o#sly. The $ewpont from wh!h they dffer s how eff!ently and a!!#rately they !an be

mplemented n dfferent sgnal+pro!essng pro!ed#res.

hle for a p#rely ele!tr!al flter t s #s#ally !lear what the amplt#de response s + a

dmensonless fa!tor by wh!h the amplt#de of a sn#sodal np#t sgnal m#st be m#ltpled to obtan

the asso!ated o#tp#t sgnal + the st#aton s not always as !lear for sesmometers be!a#se dfferent

a#thors may prefer to meas#re the np#t sgnal %the gro#nd moton& n dfferent ways" as a

dspla!ement' a $elo!ty' or an a!!eleraton. 4oth the phys!al dmenson and the mathemat!al form

of the transfer f#n!ton depend on the defnton of the np#t sgnal' and one m#st sometmes g#ess

from the phys!al dmenson to what sort of np#t sgnal t apples. The o#tp#t sgnal' tradtonally a

needle defle!ton' s now normally a $oltage' a !#rrent' or a n#mber of !o#nts.



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SEISMIC SENSOR 5

1.1 PROJECT ORGANISATION

Ths pro6e!t wor) presented the desgn and mplementaton of sesm! sensors for nd#stral

and domest! p#rpose #sng the pe,o element and a pe,o b#,,er wth ts #nderlnng prn!ple of pe,oele!tr!ty. The !r!#t #ses readly a$alable !omponents and the desgn s straght forward.

- standard e,o sensor s #sed to dete!t $bratons7so#nds d#e to press#re !hanges. The

pe,o element a!ts as a small !apa!tor ha$ng a !apa!tan!e of a few nanofarads. /)e a !apa!tor' t

!an store !harge when a potental s appled to ts termnals. It ds!harges thro#gh 8R1' when t s

dst#rbed.

The pro6e!t wor) s organ,ed as follows" !hapter two wll !on!entrate on the hardware

des!rpton wh!h s mostly on T/9:1 ;


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SEISMIC SENSOR =

CHAPTER 2

HARDWARE DESCRIPTION

HARDWARE DESCRIPTION2.1 PIEZO ELEMENT Introduction

Ths s a fo!#s on pe,oele!tr!ty as the ba!)bone behnd the operaton of ths proposed !r!#t.

e are gong to loo) at the hstory of pe,oele!tr!ty' feat#res of e,o element' b#,,er' the

proposed !r!#t dagram and some appl!atons of the pe,oele!tr!ty.

- i!"o!#!ctric $!n$or shown n


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SEISMIC SENSOR >

%i& 2.1 Pi!"o !#!ctric $!n$or

Hi$tor' o( Pi!"o!#!ctricit'

Pi!"o!#!ctricit' s a form of ele!tr!ty !reated when !ertan !rystals are bent or otherwse

deformed. These same !rystals !an also be made to bend slghtly when a small !#rrent s r#n thro#gh

them' en!o#ragng ther #se n nstr#ments for wh!h great degrees of me!han!al !ontrol are

ne!essary. Ths s !alled con)!r$! i!"o!#!ctricit'.


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SEISMIC SENSOR :

be ele!tr!ally ne#tral. hen stress s p#t on the !rystal' the symmetry s slghtly bro)en' generatng

$oltage. E$en a tny bt of pe,oele!tr! !rystal !an generate $oltages n the tho#sands.

e,oele!tr!ty s #sed n sensors' a!t#ators' motors' !lo!)s' lghters' and transd#!ers. - (#art,

!lo!) #ses pe,oele!tr!ty' as does any !garette lghter wtho#t a flnt. Med!al #ltraso#nd de$!es

!reate hgh+fre(#en!y a!o#st! $bratons #sng pe,oele!tr! !rystals. e,oele!tr!ty s #sed n

some engnes to !reate the spar) wh!h gntes the gas. /o#dspea)ers #se pe,oele!tr!ty to !on$ert

n!omng ele!tr!ty to so#nd. e,oele!tr! !rystals are #sed n many hgh+performan!e de$!es to

apply tny me!han!al dspla!ements on the s!ale of nanometers. E$en tho#gh a pe,oele!tr! !rystal

ne$er deforms by more than a few nanometers when a !#rrent s r#n thro#gh t' the for!e behnd ths

deformaton s e0tremely hgh' on the order of meganewtons. Ths deformatonal power s #sed n

me!han!s e0perments and for algnng opt!al elements many tmes hea$er than the pe,oele!tr!

!rystal tself.

The frst e0permental demonstraton of a !onne!ton between ma!ros!op! pe,oele!tr!

phenomena and !rystallograph! str#!t#re was p#blshed n 1AA9 by erre and ;a!(#es C#re. Ther

e0perment !onssted of a !on!l#s$e meas#rement of s#rfa!e !harges appearng on spe!ally

prepared !rystals %to#rmalne' (#art,' topa,' !ane s#gar and Ro!helle salt among them& wh!h were

s#b6e!ted to me!han!al stress. These res#lts were a !redt to the C#res3 magnaton and

perse$eran!e' !onsderng that they were obtaned wth nothng more than the fol' gl#e' wre'

magnets' and a 6ewelerBs saw.

S!n$or D!$i&n

4ased on pe,oele!tr! te!hnology $aro#s phys!al (#anttes !an be meas#red the most

!ommon are press#re and a!!eleraton.


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SEISMIC SENSOR A

e0peren!es a moton' the n$arant sesm! mass loads the elements a!!ordng to NewtonBs se!ond

law of moton

F ma.

The man dfferen!e n the wor)ng prn!ple between these two !ases s the way for!es areappled to the sensng elements. In a press#re sensor a thn membrane s #sed to transfer the for!e to

the elements' whle n a!!elerometers the for!es are appled by an atta!hed sesm! mass.

Sensors often tend to be senst$e to more than one phys!al (#antty. ress#re sensors show

false sgnal when they are e0posed to $bratons. Sophst!ated press#re sensors therefore #se

a!!eleraton !ompensaton elements n addton to the press#re sensng elements. 4y !aref#lly

mat!hng those elements' the a!!eleraton sgnal %released from the !ompensaton element& s

s#btra!ted from the !ombned sgnal of press#re and a!!eleraton to der$e the tr#e press#re

nformaton.

8braton sensors !an also be #sed to har$est otherwse wasted energy from me!han!al

$bratons. Ths s a!!omplshed by #sng pe,oele!tr! materals to !on$ert me!han!al stran nto

#sable ele!tr!al energy. The


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SEISMIC SENSOR

Two man gro#ps of materals are #sed for pe,oele!tr! sensors" pe,oele!tr! !eram!s and

sngle !rystal materals. The !eram! materals %s#!h as FT !eram!& ha$e a pe,oele!tr! !onstant

or senst$ty that are ro#ghly two orders of magnt#de hgher than those of sngle !rystal materals

and !an be prod#!ed by ne0pens$e snterng pro!esses. The e,o effe!t n e,o !eram!s s

traned' so #nfort#nately ther hgh senst$ty degrades o$er tme. The degradaton s hghly

!orrelated wth temperat#re. The less senst$e !rystal materals %gall#m phosphate' (#art,' and

to#rmalne& ha$e a m#!h hgher G when !aref#lly handled' almost nfnte G long term stablty.

Princi#! o( O!r*tion

Dependng on how a pe,oele!tr! materal s !#t' three man modes of operaton !an be

dstng#shed" trans$erse' longt#dnal' and shear.

• Tr*n$)!r$! !((!ct

- for!e s appled along a ne#tral a0s %y& and the !harges are generated along the %0&

dre!ton' perpend!#lar to the lne of for!e. The amo#nt of !harge depends on the geometr!al

dmensons of the respe!t$e pe,oele!tr! element. hen dmensons a' b, c apply'

C x d xy F yb 7 a

here HaB s the dmenson n lne wth the ne#tral a0s' Hb’ s n lne wth the !harge

generatng a0s and Hd’ s the !orrespondng pe,oele!tr! !oeff!ent.

• Lon&itudin*# !((!ct

The amo#nt of !harge prod#!ed s str!tly proportonal to the appled for!e and s

ndependent of s,e and shape of the pe,oele!tr! element. sng se$eral elements that are

me!han!ally n seres and ele!tr!ally n parallel s the only way to n!rease the !harge o#tp#t. The

res#ltng !harge s

C x d xx F xn


http://en.wikipedia.org/wiki/Series_and_parallel_circuitshttp://en.wikipedia.org/wiki/Series_and_parallel_circuitshttp://en.wikipedia.org/wiki/Series_and_parallel_circuits


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SEISMIC SENSOR 19

where d xx s the pe,oele!tr! !oeff!ent for a !harge n 0+dre!ton released by for!es appled

along 0+dre!ton. F x s the appled


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SEISMIC SENSOR 11

the transd#!er element. If the sensor s !onne!ted to a load resstan!e' ths also a!ts n parallel wth

the ns#laton resstan!e' both n!reasng the hgh+pass !#toff fre(#en!y.The below


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SEISMIC SENSOR 12

!an also be modeled as a !harge so#r!e n parallel wth the so#r!e !apa!tan!e' wth the !harge

dre!tly proportonal to the appled for!e' as abo$e.

• A#ic*tion$

e,oele!tr! sensors ha$e pro$en to be $ersatle tools for the meas#rement of $aro#s pro!esses.

They are #sed for (#alty ass#ran!e' pro!ess !ontrol and for resear!h and de$elopment n many

dfferent nd#stres.

It has been s#!!essf#lly #sed n $aro#s appl!atons' s#!h as n med!al' aerospa!e'

n#!lear nstr#mentaton' and as a press#re sensor n the to#!h pads of moble phones. In

the a#tomot$e nd#stry' pe,oele!tr! elements are #sed to montor !omb#ston when

de$elopng nternal !omb#ston engnes. The sensors are ether dre!tly mo#nted nto addtonal

holes nto the !ylnder head or the spar)7glow pl#g s e(#pped wth a b#lt n mnat#re pe,oele!tr!

sensor.

• Ad)*nt*&!$

The rse of pe,oele!tr! te!hnology s dre!tly related to a set of nherent ad$antages. The

hgh mod#l#s of elast!ty of many pe,oele!tr! materals s !omparable to that of many metals and

goes #p to 19= N7mJ. E$en tho#gh pe,oele!tr! sensors are ele!trome!han!al systems that rea!t to

!ompresson' the sensng elements show almost ,ero defle!ton. Ths s the reason why pe,oele!tr!sensors are so r#gged' ha$e an e0tremely hgh nat#ral fre(#en!y and an e0!ellent lnearty o$er a

wde amplt#de range.

-ddtonally' pe,oele!tr! te!hnology s nsenst$e to ele!tromagnet! felds and radaton'

enablng meas#rements #nder harsh !ondtons. Some materals #sed %espe!ally gall#m

phosphate or to#rmalne& ha$e an e0treme stablty e$en at hgh temperat#re' enablng sensors to

ha$e a wor)ng range of #p to 1999KC. To#rmalne shows pyroele!tr!ty n addton to the

pe,oele!tr! effe!t ths s the ablty to generate an ele!tr!al sgnal when the temperat#re of the!rystal !hanges. Ths effe!t s also !ommon to pe,o !eram! materals.

One dsad$antage of pe,oele!tr! sensors s that they !annot be #sed for tr#ly stat!

meas#rements. - stat! for!e wll res#lt n a f0ed amo#nt of !harges on the pe,oele!tr! materal.

hle wor)ng wth !on$entonal reado#t ele!tron!s' mperfe!t ns#latng materals' and red#!ton


http://en.wikipedia.org/wiki/Quality_assurancehttp://en.wikipedia.org/wiki/Process_controlhttp://en.wikipedia.org/wiki/Medicalhttp://en.wikipedia.org/wiki/Aerospacehttp://en.wikipedia.org/wiki/Nuclear_engineeringhttp://en.wikipedia.org/wiki/Nuclear_engineeringhttp://en.wikipedia.org/wiki/Automotive_industryhttp://en.wikipedia.org/wiki/Automotive_industryhttp://en.wikipedia.org/wiki/Internal_combustion_engineshttp://en.wikipedia.org/wiki/Modulus_of_elasticityhttp://en.wikipedia.org/wiki/Modulus_of_elasticityhttp://en.wikipedia.org/wiki/Physical_compressionhttp://en.wikipedia.org/wiki/Amplitudehttp://en.wikipedia.org/wiki/Amplitudehttp://en.wikipedia.org/wiki/Electromagnetic_fieldhttp://en.wikipedia.org/wiki/Radiationhttp://en.wikipedia.org/wiki/Radiationhttp://en.wikipedia.org/wiki/Gallium_phosphatehttp://en.wikipedia.org/wiki/Gallium_phosphatehttp://en.wikipedia.org/wiki/Gallium_phosphatehttp://en.wikipedia.org/wiki/Tourmalinehttp://en.wikipedia.org/wiki/Pyroelectricityhttp://en.wikipedia.org/w/index.php?title=Piezoceramic&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Piezoceramic&action=edit&redlink=1http://en.wikipedia.org/wiki/Quality_assurancehttp://en.wikipedia.org/wiki/Process_controlhttp://en.wikipedia.org/wiki/Medicalhttp://en.wikipedia.org/wiki/Aerospacehttp://en.wikipedia.org/wiki/Nuclear_engineeringhttp://en.wikipedia.org/wiki/Automotive_industryhttp://en.wikipedia.org/wiki/Internal_combustion_engineshttp://en.wikipedia.org/wiki/Modulus_of_elasticityhttp://en.wikipedia.org/wiki/Physical_compressionhttp://en.wikipedia.org/wiki/Amplitudehttp://en.wikipedia.org/wiki/Electromagnetic_fieldhttp://en.wikipedia.org/wiki/Radiationhttp://en.wikipedia.org/wiki/Gallium_phosphatehttp://en.wikipedia.org/wiki/Gallium_phosphatehttp://en.wikipedia.org/wiki/Tourmalinehttp://en.wikipedia.org/wiki/Pyroelectricityhttp://en.wikipedia.org/w/index.php?title=Piezoceramic&action=edit&redlink=1


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SEISMIC SENSOR 1

n nternal sensor resstan!e wll res#lt n a !onstant loss of ele!trons' and yeld a de!reasng sgnal.

Ele$ated temperat#res !a#se an addtonal drop n nternal resstan!e and senst$ty. The man effe!t

on the pe,oele!tr! effe!t s that wth n!reasng press#re loads and temperat#re' the senst$ty s

red#!ed d#e to twn+formaton. hle (#art, sensors need to be !ooled d#rng meas#rements at

temperat#res abo$e 99KC' spe!al types of !rystals l)e LaO5 gall#m phosphate do not show any

twn formaton #p to the meltng pont of the materal tself.

*owe$er' t s not tr#e that pe,oele!tr! sensors !an only be #sed for $ery fast pro!esses or at

ambent !ondtons. In fa!t' there are n#mero#s appl!atons that show (#as+stat! meas#rements'

whle there are other appl!atons wth temperat#res hgher than =99KC.

e,oele!tr! sensors are also seen n nat#re. Dry bone s pe,oele!tr!' and s tho#ght by

some to a!t as a bolog!al for!e sensor.

2.2 PIEZO 6UZZER

- 0u""!r or 0!!!r s an a#do sgnalng de$!e' wh!h may be me!han!al' ele!tro+

me!han!al' or ele!tron!. Typ!al #ses of b#,,ers and beepers n!l#de alarms' tmers and!onfrmaton of #ser np#t s#!h as a mo#se !l!) or )eystro)e. The shows pe,oele!tr! ds)

beeper.

%i& 2.7 i!"o!#!ctric di$+ 0!!!r

• M!c-*nic*#

- 6oy b#,,er s an e0ample of a p#rely me!han!al b#,,er.


http://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Internal_resistancehttp://en.wikipedia.org/wiki/Gallium_phosphatehttp://en.wikipedia.org/wiki/Bonehttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Internal_resistancehttp://en.wikipedia.org/wiki/Gallium_phosphatehttp://en.wikipedia.org/wiki/Bone


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SEISMIC SENSOR 15

• E#!ctro!c-*nic*#

Early de$!es were based on an ele!trome!han!al system dent!al to an ele!tr!

bell wtho#t the metal gong. Smlarly' a relay may be !onne!ted to nterr#pt ts own

a!t#atng !#rrent' !a#sng the !onta!ts to b#,,. Often these #nts were an!hored to a wall or !elng

to #se t as a so#ndng board. The word b#,,er !omes from the raspng nose that

ele!trome!han!al b#,,ers made.

• E#!ctronic

- pe,oele!tr! element may be dr$en by an os!llatng ele!tron! !r!#t or other a#do

sgnal so#r!e. So#nds !ommonly #sed to nd!ate that a b#tton has been pressed are a !l!)' a rng or

a beep. Ele!tron! b#,,ers fnd many appl!atons n modern days.

2. TL891

Ths wll fo!#s on the feat#res of the T/9:1 /ow nose ;


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SEISMIC SENSOR 1=

%i& 2.9 in conn!ction o( T#891 IC

1 + Offset n#ll 1

2 + In$ertng np#t

+ Non+n$ertng np#t

5 + 8CC+

= + Offset n#ll 2

> + O#tp#t

: + 8CC

A + N.C.

%!*tur!$ o( TL891 IC

Tl9:1 IC s a slghtly for powerf#l ;


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SEISMIC SENSOR 1>

• Internal fre(#en!y !ompensaton• /at!h+#p free operaton• *gh slew rate" 1>8 7Qs

-ll $oltage $al#es' e0!ept dfferental $oltage' are wth respe!t to the ,ero referen!e le$el

%gro#nd& of the s#pply $oltages where the ,ero referen!e le$el s the mdpont between 8CC and

8CC. The magnt#de of the np#t $oltage m#st ne$er e0!eed the magnt#de of the s#pply $oltage or

1= $olts' wh!he$er s less. Dfferental $oltages are the non+n$ertng np#t termnal wth respe!t to

the n$ertng np#t termnal. Short+!r!#ts !an !a#se e0!ess$e heatng. Destr#!t$e dsspaton !an

res#lt from sm#ltaneo#s short+!r!#ts on all amplfers. Rth are typ!al $al#es. The o#tp#t may be

shorted to gro#nd or to ether s#pply. Temperat#re and7or s#pply $oltages m#st be lmted to ens#re

that the dsspaton ratng s not e0!eeded.

*#man body model" 199p< ds!harged thro#gh a 1.=) resstor between two pns of the

de$!e' done for all !o#ples of pn !ombnatons wth other pns floatng. Ma!hne model" a 299p<

!ap s !harged to the spe!fed $oltage' then ds!harged dre!tly between two pns of the de$!e wth

no e0ternal seres resstor %nternal resstor = &' done for all !o#ples of pn !ombnatons wth

other pns floatng. Charged de$!e model" all pns pl#s pa!)age are !harged together to the spe!fed

$oltage and then ds!harged dre!tly to the gro#nd. The np#t bas !#rrents are 6#n!ton lea)age

!#rrents wh!h appro0mately do#ble for e$ery 19KC n!rease n the 6#n!ton temperat#re.

2.4 NE555 Ti!r IC

O)!r)i!,

The === Tmer IC s an ntegrated !r!#t %!hp& mplementng a $arety

of tmer and m#lt$brator appl!atons. The IC was desgned by *ans R. Camen,nd n1:9 and

bro#ght to mar)et n 1:1 by Sgnet!s %later a!(#red by hlps&. The orgnal name was the SE===

%metal !an&7NE=== %plast! DI& and the part was des!rbed as The IC Tme Ma!hne.


http://en.wikipedia.org/wiki/Integrated_circuithttp://en.wikipedia.org/wiki/Timerhttp://en.wikipedia.org/wiki/Multivibratorhttp://en.wikipedia.org/wiki/Hans_R._Camenzindhttp://en.wikipedia.org/wiki/Hans_R._Camenzindhttp://en.wikipedia.org/wiki/1970http://en.wikipedia.org/wiki/1971http://en.wikipedia.org/wiki/Signeticshttp://en.wikipedia.org/wiki/Philipshttp://en.wikipedia.org/wiki/DIP-8http://en.wikipedia.org/wiki/Integrated_circuithttp://en.wikipedia.org/wiki/Timerhttp://en.wikipedia.org/wiki/Multivibratorhttp://en.wikipedia.org/wiki/Hans_R._Camenzindhttp://en.wikipedia.org/wiki/1970http://en.wikipedia.org/wiki/1971http://en.wikipedia.org/wiki/Signeticshttp://en.wikipedia.org/wiki/Philipshttp://en.wikipedia.org/wiki/DIP-8


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SEISMIC SENSOR 1:

It has been !lamed that the === gets ts name from the three = ) resstors #sed n typ!al

early mplementatons' b#t *ans Camen,nd has stated that the n#mber was arbtrary. The part s stll

n wde #se' than)s to ts ease of #se' low pr!e and good stablty. -s of 299' t s estmated that 1 bllon #nts are man#fa!t#red e$ery year.

Dependng on the man#fa!t#rer' the standard === pa!)age n!l#des o$er 29 transstors'

2 dodes and 1= resstors on a sl!on !hp nstalled n an A+pn mn d#al+n+lne pa!)age %DI+

A&. 8arants a$alable n!l#de the ==> %a 15+pn DI !ombnng two ===s on one !hp&' and the ==A %a

1>+pn DI !ombnng fo#r slghtly modfed ===s wth DIS T*R !onne!ted nternally' and TR

fallng edge senst$e nstead of le$el senst$e&.

ltra+low power $ersons of the === are also a$alable' s#!h as the :=== and T/C===. The

:=== re(#res slghtly dfferent wrng #sng fewer e0ternal !omponents and less power.

The === has three operatng modes"

• Monostable mode" n ths mode' the === f#n!tons as a one+shot. -ppl!atons n!l#de tmers'

mssng p#lse dete!ton' bo#n!e free swt!hes' to#!h swt!hes' fre(#en!y d$der' !apa!tan!e

meas#rement' p#lse+wdth mod#laton %M& et!

• -stable + free r#nnng mode" the === !an operate as an os!llator . ses n!l#de /ED and

lamp flashers' p#lse generaton' log! !lo!)s' tone generaton' se!#rty alarms' p#lse poston

mod#laton' et!.

• 4stable mode or S!hmtt trgger " the === !an operate as a flp+flop' f the DIS pn s not

!onne!ted and no !apa!tor s #sed. ses n!l#de bo#n!e free lat!hed swt!hes' et!.

Pin Out$ : D!$crition$


http://en.wikipedia.org/wiki/Ohmhttp://en.wikipedia.org/wiki/1000000000_(number)http://en.wikipedia.org/wiki/1000000000_(number)http://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/Resistorhttp://en.wikipedia.org/wiki/Resistorhttp://en.wikipedia.org/wiki/DIP-8http://en.wikipedia.org/wiki/DIP-8http://en.wikipedia.org/wiki/Monostablehttp://en.wikipedia.org/wiki/Astablehttp://en.wikipedia.org/wiki/Oscillatorhttp://en.wikipedia.org/wiki/Oscillatorhttp://en.wikipedia.org/wiki/LEDhttp://en.wikipedia.org/wiki/Pulse_position_modulationhttp://en.wikipedia.org/wiki/Pulse_position_modulationhttp://en.wikipedia.org/wiki/Pulse_position_modulationhttp://en.wikipedia.org/wiki/Bistablehttp://en.wikipedia.org/wiki/Bistablehttp://en.wikipedia.org/wiki/Schmitt_triggerhttp://en.wikipedia.org/wiki/Schmitt_triggerhttp://en.wikipedia.org/wiki/Flip-flop_(electronics)http://en.wikipedia.org/wiki/Flip-flop_(electronics)http://en.wikipedia.org/wiki/Ohmhttp://en.wikipedia.org/wiki/1000000000_(number)http://en.wikipedia.org/wiki/1000000000_(number)http://en.wikipedia.org/wiki/Transistorhttp://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/Resistorhttp://en.wikipedia.org/wiki/DIP-8http://en.wikipedia.org/wiki/DIP-8http://en.wikipedia.org/wiki/Monostablehttp://en.wikipedia.org/wiki/Astablehttp://en.wikipedia.org/wiki/Oscillatorhttp://en.wikipedia.org/wiki/LEDhttp://en.wikipedia.org/wiki/Pulse_position_modulationhttp://en.wikipedia.org/wiki/Pulse_position_modulationhttp://en.wikipedia.org/wiki/Bistablehttp://en.wikipedia.org/wiki/Schmitt_triggerhttp://en.wikipedia.org/wiki/Flip-flop_(electronics)


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SEISMIC SENSOR 1A

The === ntegrated !r!#t s a hghly a!!#rate tmng !r!#t that s !apable of prod#!ng

ether tme delays or os!llaton. The


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SEISMIC SENSOR 1

%i& 2.< NE555 Ti!r IC 0#oc+ di*&r*



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SEISMIC SENSOR 29

Mono$t*0#! O!r*tion

The !r!#t dagram shown n


21/46

SEISMIC SENSOR 21

to n!rease. hen t rea!hes 27 8 the


22/46

SEISMIC SENSOR 22

T'!$ o( Tr*n$i$tor$

There are two types of standard transstors' NPN and PNP' wth dfferent !r!#t symbols.

The letters refer to the layers of sem!ond#!tor materal #sed to ma)e the transstor. Most

transstors #sed today are NN be!a#se ths s the easest type to ma)e from sl!on. The


23/46

SEISMIC SENSOR 2

PNP

The other type of 4;T s the N wth the letters and N referrng to the ma6orty !harge

!arrers nsde the dfferent regons of the transstor. N transstors !onsst of a layer of N+doped

sem!ond#!tor between two layers of +doped materal. - small !#rrent lea$ng the base n !ommon+emtter mode s amplfed n the !olle!tor o#tp#t. In other terms' a N transstor s on when ts

base s p#lled low relat$e to the emtter. The arrow n the N transstor symbol s on the emtter leg

and ponts n the dre!ton of the !on$entonal !#rrent flow when the de$!e s n forward a!t$e

mode.

Wor+in& o( Tr*n$i$tor

The essental #sef#lness of a transstor !omes from ts ablty to #se a small sgnal appled between one par of ts termnals to !ontrol a m#!h larger sgnal at another par of termnals. Ths

property s !alled gan. - transstor !an !ontrol ts o#tp#t n proporton to the np#t sgnal ths s

!alled an amplfer. Or' the transstor !an be #sed to t#rn !#rrent on or off n a !r!#t l)e an

ele!tr!ally !ontrolled swt!h' where the amo#nt of !#rrent s determned by other !r!#t elements.

The two types of transstors ha$e slght dfferen!es n how they are #sed n a !r!#t. - bpolar transstor has termnals labeled base' !olle!tor and emtter. - small !#rrent at base termnal

!an !ontrol or swt!h a m#!h larger !#rrent between !olle!tor and emtter termnals.


24/46

SEISMIC SENSOR 25

• U$!$

The bpolar 6#n!ton transstor' or 4;T' was the most !ommonly #sed transstor n the 1>9s and

:9s. E$en after MOS


25/46

SEISMIC SENSOR 2=

Ad)*nt*&!$

The )ey ad$antages that ha$e allowed transstors to repla!e ther $a!##m t#be prede!essors n

most appl!atons are

• Small s,e and mnmal weght' allowng the de$elopment of mnat#r,ed ele!tron! de$!es.

• *ghly a#tomated man#fa!t#rng pro!esses' res#ltng n low per+#nt !ost.

• /ower possble operatng $oltages' ma)ng transstors s#table for small' battery+powered

appl!atons.

• No warm+#p perod for !athode heaters re(#red after power appl!aton.

• /ower power dsspaton and generally greater energy eff!en!y.

• *gher relablty and greater phys!al r#ggedness.

• E0tremely long lfe. Some transstor,ed de$!es ha$e been n ser$!e for more than =9 years.

• Complementary de$!es a$alable' fa!ltatng the desgn of !omplementary+

symmetry !r!#ts' somethng not possble wth $a!##m t#bes.

• Insenst$ty to me!han!al sho!) and $braton' th#s a$odng the problem of m!ro

phon!s n a#do appl!atons.

Liit*tion$

• Sl!on transstors do not operate at $oltages hgher than abo#t 1'999 $olts %S! de$!es !an

be operated as hgh as '999 $olts&. In !ontrast' ele!tron t#bes ha$e been de$eloped that !an

be operated at tens of tho#sands of $olts.

• *gh power' hgh fre(#en!y operaton' s#!h as that #sed n o$er+the+ar tele$son

broad!astng' s better a!he$ed n ele!tron t#bes d#e to mpro$ed ele!tron moblty n a

$a!##m.



26/46

SEISMIC SENSOR 2>

• Sl!on transstors are m#!h more $#lnerable than ele!tron t#bes to an ele!tromagnet!

p#lse generated by a hgh+altt#de n#!lear e0ploson.

2.7 RESISTOR

- r!$i$tor s a two+termnal ele!tron! !omponent that prod#!es a $oltage a!ross ts termnals

that s proportonal to the ele!tr! !#rrent thro#gh t n a!!ordan!e wth Ohm3s law"

V IR

%i& 2.1 A t'ic*# *=i*#>#!*d r!$i$tor

*ere


27/46

SEISMIC SENSOR 2:

Resstors !an be ntegrated nto hybrd and prnted !r!#ts' as well as ntegrated !r!#ts. S,e'

and poston of leads %or termnals&' are rele$ant to e(#pment desgners resstors m#st be phys!ally

large eno#gh not to o$erheat when dsspatng ther power.

Unit$

The ohm %symbol" & s the SI #nt of ele!tr!al resstan!e' named after Leorg Smon Ohm.

Commonly #sed m#ltples and s#bm#ltples n ele!tr!al and ele!tron! #sage are the mllohm

%1019V&' )lohm %1019&' and megohm %1019>&.

T-!or' o( o!r*tion

O-?$ #*,

The beha$or of an deal resstor s d!tated by the relatonshp spe!fed n Ohm3s law"

Ohm3s law states that the $oltage %8& a!ross a resstor s proportonal to the !#rrent %I&

thro#gh t where the !onstant of proportonalty s the resstan!e %R&.

E(#$alently' Ohm3s law !an be stated"

Ths form#laton of Ohm3s law states that' when a $oltage %8& s mantaned a!ross a

resstan!e %R&' a !#rrent %I& wll flow thro#gh the resstan!e.

@ARIA6LE RESISTOR

There are two )nds of resstors'


28/46

SEISMIC SENSOR 2A

potentometer s the $ol#me !ontrol on yo#r rado' and an e0ample of the rheostat s the dmmer

!ontrol for the dash lghts n an a#tomoble. There s a slght dfferen!e between them.

Rheostats #s#ally ha$e two !onne!tons' one f0ed and the other mo$eable. -ny $arable

resstor !an properly be !alled a rheostat. The potentometer always has three !onne!tons' two f0ed

and one mo$eable. Lenerally' the rheostat has a lmted range of $al#es and a hgh !#rrent+handlng

!apablty. The potentometer has a wde range of $al#es' b#t t #s#ally has a lmted !#rrent+

handlng !apablty. otentometers are always !onne!ted as $oltage d$ders.


29/46

SEISMIC SENSOR 2

C**cit*nc!

Ths s a meas#re of a !apa!tor3s ablty to store !harge. - large !apa!tan!e means that more

!harge !an be stored. Capa!tan!e s meas#red n farads %


30/46

SEISMIC SENSOR 9

%i& 2.17 Circuit S'0o# o( Po#*ri"!d C**citor

E#!ctro#'tic C**citor$

Ele!trolyt! !apa!tors are polar,ed and they m#st be !onne!ted the !orre!t way ro#nd' at

least one of ther leads wll be mar)ed or +. They are not damaged by heat when solderng. There

are two desgns of ele!trolyt! !apa!tors a0al where the leads are atta!hed to ea!h end and radal

where both leads are at the same end. Radal !apa!tors tend to be a lttle smaller and they stand

#prght on the !r!#t board.

It s easy to fnd the $al#e of ele!trolyt! !apa!tors be!a#se they are !learly prnted wth ther

!apa!tan!e and $oltage ratng. The $oltage ratng !an be (#te low %>8 for e0ample& and t sho#ld

always be !he!)ed when sele!tng an ele!trolyt! !apa!tor. If the pro6e!t parts lst does not spe!fy a$oltage' !hoose a !apa!tor wth a ratng wh!h s greater than the pro6e!t3s power s#pply $oltage.

2=8 s a sensble mnm#m most battery !r!#ts.


31/46

SEISMIC SENSOR 1

T*nt*#u 6!*d C**citor$

Tantal#m bead !apa!tors are polar,ed and ha$e low $oltage ratngs l)e ele!trolyt!

!apa!tors. They are e0pens$e b#t $ery small' so they are #sed where a large !apa!tan!e s needed

n a small s,e.


32/46

SEISMIC SENSOR 2

%i& 2.1< LED$

4l#e' green' and red /EDs shown n


33/46

SEISMIC SENSOR

!ommonly #sed n po!)et transstor rados' smo)e dete!tors' !arbon mono0de alarms' g#tar

effe!t #nts' and rado+!ontrolled $eh!le !ontrollers. They are also #sed as ba!)#p power to )eep the

tme n dgtal !lo!)s and alarm !lo!)s.


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SEISMIC SENSOR 5

CHAPTER

DESIGN AND IMPLEMENTATION O%

SEISMIC SENSOR

DESIGN AND IMPLEMENTATION O% SEISMIC SENSOR



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SEISMIC SENSOR =

In ths !hapter we wll ds!#ss the blo!) dagram' !r!#t dagram' bas! operaton and wor)ng

of sesm! sensor n detal.

.1 6LOC DIAGRAM

The


36/46

SEISMIC SENSOR >

%i& .2 Circuit di*&r* (or t-! $!i$ic $!n$or

The !r!#t #ses readly a$alable !omponents and the desgn s straght+forward. - standard

pe,o sensor s #sed to dete!t $bratons7so#nds d#e to press#re !hanges. The pe,o element a!ts as a

small !apa!tor ha$ng a !apa!tan!e of a few nanofarads. /)e a !apa!tor' t !an store !harge when

a potental s appled to ts termnals. It ds!harges thro#gh 8R1' when t s dst#rbed. In the !r!#t'


IC2

NE555

IC1

TL071

C510µF25V

C610µF25V

2

4

7

6

3

R51kΩ

R6470kΩ

LEDI

LED

2

R71MΩ

R9 470Ω

T1BC548 T2

BC548

C3100µF25V

C40.01µF

C20.1µF

9V BATTERY

8

1 5

R81KΩ

PIE!B"ER

R1 100KΩ

R210KΩ

R3100KΩ

PIE!

ELEMENT

VR11MΩ

R4330Ω

C110µF25V

2

3

7

4

6


37/46

SEISMIC SENSOR :

IC T/O:1 %IC1& s wred as a dfferental amplfer wth both ts n$ertng and non+n$ertng np#ts

ted to the negat$e ral thro#gh a resst$e networ) !omprsng R1' R2 and R. nder dle !ondtons

%as ad6#sted by 8R1&' both the np#ts re!e$e almost e(#al $oltages' wh!h )eeps the o#tp#t low.

T/O:1 s a low+nose ;


38/46

SEISMIC SENSOR A

!#rrent. The 4I


39/46

SEISMIC SENSOR

8!! 84E IR R /

T1 I4 1.:7R 5

1.:79

9.99=2 -

T2 I4 1.:7R A

1.:71 Z19

9.991: -

The tmng perod of IC2 s determned by R: and C=.

T 1.11 ZR = Z C:

1.11 Z 1 0 19> Z 19 019+>

11 se!onds.

.7 %LOWCHART

The flow!hart n a shows the flow !ontrol or pro!esses of operaton of the sesm! sensor.


DISTUR6ANC

E O% PIEZO

ELEMENT

IC1

@OLTAGE

LE@EL IS

ALTERED

SWITCHING

TRANSISTOR

T2 IS

TRIGGERED

MONOSTA6LE

TO IC2 #$%&&'$

HIGH OUTPUT

O% IC2

ACTI@ATES T2

6UZZER

STARTS TO

6EEP


40/46

SEISMIC SENSOR 59

%i& . %#o, c-*rt (or $!i$ic $!n$or u$in& i!"o !#!!nt



41/46

SEISMIC SENSOR 51

CHAPTER 4

APPLICATIONS O% SEISMIC SENSOR

APPLICATIONS O% SEISMIC SENSOR

1. It !an be #sed at all the pla!es where we re(#re a lot of se!#rty e.g. n 4an) lo!)ers' n

6eweler showrooms et!.

2. It !an also be #sed at the areas where h#man or any anmal entry s not allowed %e.g. Danger

,ones&.



42/46

SEISMIC SENSOR 52



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SEISMIC SENSOR 5

CHAPTER 5

CONCLUSIONS AND %UTURE SCOPE

CONCLUSIONS AND %UTURE SCOPE

1. Ths s a low b#dget pro6e!t so any one !an #se t easly.

2. It wll help n many ways f we #se a hgh eff!en!y pe,o element and pe,o b#,,er.

. Ths pro6e!t !an also be e0tended nto the sesmometer or the earth(#a)e dete!tors.



44/46

SEISMIC SENSOR 55



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SEISMIC SENSOR 5=

CHAPTER 7

RE%ERENCES

RE%ERENCES

1. http"77www.ele!tron!sfor#.!om.2. www.pe,oele!tr!materals.!om.. En.w)peda.org7w)7pe,oele!tr!ty'resstor'transstor'!apa!tor.4. www.!r!#tstoday.!om7 ===tmer+as+monostablem#lt$brator' ICT/9:1.


http://www.electronicsforu.com/http://www.piezoelectricmaterials.com/http://www.electronicsforu.com/http://www.piezoelectricmaterials.com/


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SEISMIC SENSOR 5>

5. www.s!rbd.!om7 Desgn and Implementaton of Sesm! Sensor.7. Sal$ahanan' S#resh U#mar' 8alla$ara6 ?Ele!tron! De$!es and Cr!#ts@' Tata M!Lraw

*ll' 5e.9. Srn$asan ?Ele!tron! Cr!#t -nalyss@' -n#radha #bl!atons' 2e.
http://www.scribd.com/http://www.scribd.com/

seismic sensor final doc

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