Astable Multivibrator Report

PHYSICS PROJECT FILE

AIM To construct and study An Astable Multivibrator And Study its operation

Certifcate This is to certiy that __________(nae!" st#$ent o C%ass &II A" _________________________________(schoo%!" has co'%ete$ the 'roect tit%e$ ASTA)LE M*LTI+I)RATOR $#rin, the aca$eic year -./01/2 to3ar$s 'artia% #%f%%ent o cre$it or the Physics 'ractica% e4a%#ation o C)SE an$ has s#5itte$ a satisactory re'ort" as co'i%e$ in the o%%o3in, 'a,es" #n$er the s#'er4ision o his Physics teacher ___________(T67ae!6

________________ ________________ (PHYSICS TEACHER!

(PRI7CIPAL!

Ac8no3%e$, eents I ha4e 5een s#''orte$ 5y any 'eo'%e to co'%ete this 'roect6

Ia%% 3o#%$ to than8 Sector e +III this R696P#ra o its%i8e e5ers or96+6 'ro4i$in, #ni:#e an$ o''ort#nity or se%1%earnin,6 I a 4ery ,rate#% to co'#ter science teacher" Mr6 Pra4een 9#ar or his ora% s#''ort an$ ,#i$ance6

;#rin, this st#$y" I ha4e 5ecoe in$e5te$ to any in$i4i$#a%s 3itho#t 3hose 3i%%in, cor'oration" I 3o#%$n
I a a%so 4ery than8#% to y 'arents or their incre$i5%e

s#''ort in e4erythin, I ha4e $one6

MULTIVIBRATOR: A multivibrator is an electronic circuit used to implement a variety of simple twostate systems suc! as li"!t emittin" diodes# timers and flipflops$ It is c!aracteri%ed by two amplifyin" devices &transistors# electron tubes or ot!er devices' crosscoupled by resistors and capacitors$

In its simplest form t!e multivibrator circuit consists of two crosscoupled transistors$ Usin" resistorcapacitor networ(s wit!in t!e circuit to define t!e time periods of t!e unstable states# t!e various types may be implemented$

T)*+, O- MULTIVITBRATOR, T!ere are t!ree types of multivibrator circuit: •

•

•

Astable# in w!ic! t!e circuit is not stable in eit!er state it continuously oscillates from one state to t!e ot!er$ Monostable# in w!ic! one of t!e states is stable# but t!e ot!er is not t!e circuit will flip into t!e unstable state for a determined period# but will eventually return to t!e stable state$ ,uc! a circuit is useful for creatin" a timin" period of fi.ed duration in response to some e.ternal event$ T!is circuit is also (nown as a one s!ot$ A common application is in eliminatin" switc! bounce$ Bistable# in w!ic! t!e circuit will remain in eit!er state indefinitely$ T!e circuit can be flipped from one state to t!e ot!er by an e.ternal event or tri""er$ ,uc! a circuit is important as t!e fundamental buildin" bloc( of a re"ister or memory device$ T!is circuit is also (nown as a flipflop$

Multi vibrators find applications in a variety of systems w!ere s/uare waves or timed intervals are re/uired$ ,imple circuits tend to be inaccurate since many factors affect t!eir timin"# so t!ey are rarely used w!ere very !i"! precision is re/uired$

0IR0UIT 1IA2RAM

03 and 04 are capacitors in -arads$ T is time constant$

0OM*O5+5T, U,+1

• • • • • • • • •

B0678 5*5 transistors 79#3;7 < resistors 79=R# > < resistors 3=# > < resistors 3=U-# electrolytic capacitors ?V battery 0onnectin" wires Battery snapper L+1&s' red


Transistors @3 and @4 are confi"ured as an astable multivibrator w!ic! means one of t!e two transistors is always conductin"$ ,ince transistors do not conduct to"et!er# L+1s also do not "low to"et!er$
Mathematical formula for calculating f requency: f

 3;T

>

f

 3; C&=$D?E'.R.0 F

>

f

 3; C&=$D?E' . & &R3.03' G &R4.04' 'F






THA79 YO*==