Eeb 1282 Circuits Mchs and Devices Lab - Fair Try 1 (1)_1458750943725

7/26/2019 Eeb 1282 Circuits Mchs and Devices Lab - Fair Try 1 (1)_1458750943725

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EEB 1282 - LAB MANUAL FOR CSE A RA, AS

VERIFICATION OF KIRCHOFFS LAWS

EXPERIMENT No.:

INTRODUCTION:

Network equations are formulated from two simple laws that were first

expressedby Kirchoff in 1845. These laws concern the alebraic sum of !oltaes around aloop and currents lea!in or enterin a node. "t is interestin to note that Kirchoffwas a #$ year old student at the time of the first publication of these laws.

STATEMENTS:

Kirchoffs Vo!"#$ L"%: Kirchoffs voltage law states that the alebraic sum of all branch!oltaes around any closed loop of a network is %ero at all instants of time.

Kirchoffs c&rr$'! "%: Kirchoffs current law states that the alebraic sum of all branchcurrents lea!in a node is %ero at all instants of time. &The law is a consequenceof conser!ation of chare. 'hare which enters a node should lea!e the nodebecause it can(t be stored there.)

O()ECTIVE:

To !erify Kirchoff(s current and !oltae *aws for a i!en circuit.

APPARATUS RE*UIRED:

S.No

N"+$ of !h$co+,o'$'!

R"'#$ *&"'!i!-

1. +eulated powersupply

&,-$,) #

#. +esistors ##, #

$$, 1

4/ 1

08 1

$. mmeter &,-1,)m 1

4. 2iital 3ultimeter 1

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CIRCUIT DIARAM:



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Fi#. /./

TA(ULATION:

PROCEDURE FOR VERIFICATION OF KVL:

1. i!e connections as per circuit diaram.#. witch on the supply !oltae.$. Note the !oltae across the !oltae source6 and the !oltae &drops) across

the resistors &usin a multi-meter) in the closed loop.4. 'heck whether the sum of !oltae rises in the closed loop is equal to the sum

of !oltae drops.5. 'heck these obser!ed !alues with the theoretical !alues calculated usin the

alebraic equations formulated based on the K7* law.

PROCEDURE FOR VERIFICATION OF KCL:

1. i!e connections as per circuit diaram.#. witch on the supply !oltae.$. 'heck whether the sum of the incomin currents to a node is equal to the

sum of the out oin currents from that node.4. 'heck these obser!ed !alues with the theoretical !alues calculated usin the

alebraic equations formulated based on the K'* law.

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(RANCHTHEORETICALCALCULATION

O(SERVED VALUES

CURRENT0+A1

VOLTAE0V1

CURRENT0+A1

VOLTAE0V1

9

2

'

92

'2


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RESULT:Kirchoff(s current and !oltae laws ha!e been !erified for the i!en circuit.

VIVA *UESTIONS:/. tate :hm(s law.

2. tate Kirchoff(s current law.3. tate Kirchoff(s !oltae law.4. ;hat do you mean by a nodeower

>i&;atts)

9fficiency

A1K A#K

+adius of the brake drum6 r C

MODEL CALCULATION:

'ircumference of the brake drum C cms

+adius6 r C mt.

Torque applied on the shaft of the motor6 T C &A1E A#) + F.81 Nm

+ C rGt?#D r C '?#H

:utput power6 >o C

WattsNT

.0

2

"nput >ower6 >i C 7 I " ;atts

J 9fficiency6 C

100i

o

P

P

R is the effecti!e radius of the brake drum in meter < r=!>2

r 2

c C circumference of brake drum in m. t C thickness of belt in m.



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(

N, , , /

/(

N

/a

/a

N

N


MODEL RAPHS:

Disc&ssio' *&$s!io's:

1. ow does the back emf in a d.c. motor make the motor self reulatinosition. $. 2o not start the motor under loaded condition and release the

load before stoppin. 4. >our water in brake drum to pre!ent it from o!erheatin.

5. 3ake sure that all the meters connected are mo!in coil type.

PROCEDURE: 1. 3ake the connections as shown in the circuit diaram. #. :bser!in all the precautions6 start the motor with the help of

the three point starter. $.;ith the help of field rheostat6 ad=ust the speed of the motor to

the rated speed and note the initial readins of the ammeterand !oltmeter of the motor circuit.

4. pply the load radually in steps6 till the motor draws 1#,J ofthe rated current from the supply and at each step note the

meter readins6 speed and the sprin balance readins. 5. +elease the load and brin back the motor field rheostat to

minimum position and switch off the motor.

O(SERVATION:

Vo!@"#$i'

7o!s

VL

C&rr$'! i'"+,s

S,$$@ i'r,+

S,ri'#""'c$r$"i'#s

TorB&$i' N+

I',&! O&!,&! S,$$R$#&"!io'

"* "A "a S/ S2

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FORMULA USED: I',&! < I',&! 7o!"#$ I',&! c&rr$'! < VI %"!!s

O&!,&! < 2NT>6G %"!!s N C peed in rpm.

TorB&$ < 0S/S21 .J/ R N@+ ;here 1 and # are sprin balance readins in K R is the effecti!e radius of the brake drum in meter < r=!>2

r 2

c C circumference of brake drum in m. t C thickness of belt in m.

Effici$'c- < O&!,&! > I',&! /GG

S,$$ R$#&"!io' < N'oo"@ Nf&o"> N'oo"

RESULT:

*UESTIONS:

1. ;hy the 2' shunt motor is started on no load< #. ;hat are the applications of 2' shunt motor< $. ;hy the field rheostat is kept in minimum resistance position &.)? 999O.C.C AND LOAD TESTS ON SELF EXCITED D.C. SHUNT ENERATOR

EXPERIMENT No.:

O()ECTIVES:

1. To obtain the :.'.' cur!e.

#. To deduce the :.'.'. for !arious speeds.

$. To determine the critical field resistance and critical speed.

KNOWLEDE RE*UIRED:

93A equation of enerator

+elation between enerator 93A and speed.

'ritical field resistance and critical speed.

aturation of manetic poles and retenti!ity property of manetic material.

CIRCUIT DIARAMS:

MEASUREMENT OF RAFOR ENERATOR

"a

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A -

$

-

3SS

-

22( $

3.C

4

44

AA

-


7a

M$"s&r$+$'! of Rshof $'$r"!or"f

7f

S$f Eci!"!io':

"*

7*

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"f

MOTOR SPECIFICATIONS ENERATOR SPECIFICATIONS>owerD 7oltsDpeedD 'urrentDAield 'urrentD

>owerD 7oltsDpeedD 'urrentDAield 'urrentD

RANE FIXIN:

+heostats on field circuit of motor and enerator.

Their current ratin is to be based on their rated field current

Their ohmic !alue should be as hih as possible &especially for enerator

side) "f ased on rated field current of enerator

"* ased on rated or 1#,J of rated current of enerator

7 ased on rated !oltae of enerator

FUSE RATINS:

#,J of rated current for :' test 1#,J of rated current for ' test

PRECAUTIONS:

The motor field rheostat should be in minimum resistance position and the

enerator field rheostat should be in maximum resistance position whileswitchin on and switchin off the supply side 2>T.

9nsure that no load is connected6 while switchin on and switchin off the

supply side 2>T.PROCEDURE:O.C. TEST: 1.'onnections are made as per the circuit diaram .

#.+un the 3.. set at rated speed by ad=ustin the motor field rheostat afterclosin the supply side 2>T.$. Keepin the 2>T on load side and the >T in open condition6 note the!oltae induced &"fC ,).



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4. 'lose the >T and obser!e 7 for uniform increase of " f till the maneticpoles are saturated.

Lo" !$s!: 1. 'onnections are made as per the circuit diaram.

#. +un the 3 set at rated speed.

$. 9xcite the enerator to its rated !oltae after closin the >T6 andobser!e the readins on no load.4. 'lose the 2>T on load side6 !ary the load for con!enient steps of load current and obser!e the meter readins.5. Note that on each loadin the speed should be rated speed.0. *oad the enerator up to its rated capacity.

O(SERVATION:

OC TEST:

Lo" T$s!:

peedD .............. +>3P No load !oltaeD ............. !olts

l.No.

Terminal!oltae&7t)

*oad current"*

"f "a9C 7t G

"a+a

No!$: Tabular column for +aand +share common. >repare separate tabular columnsfor :' and load test for separate and self excitation.

MODEL CALCULATION:

O.C.


$+o+

(Amp)

E0(*ot)

MEASUREMENT OF RA:

$+ o+ *a

(*ot)

a

(Amp)

Ra4 *a/a

(5hm)

MEASUREMENT OF RSH:

$+ o+ *h h R h4 *h/h


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R0h L67e

E(

/

R% 967e

O.C.C. L67e

$, Eg

/L, /a

$ )0 /L

Eg )0 /a

C

B

A


9,N

o6 for different speeds6 :.'.'. can be deduced from the :.'.'.at rated speed.

LOAD TEST:

Aor separate excitation "aC "*Aor self excitation "aC "*G "fo6 induced emf on load6 9C 7 G "a+a

2raw +cline6 such that it is tanent to the initial portion of :.'.'. at rated speed andpasses throuh oriin.

The !alue of critical field resistance6 +cC the slope of +c line

'ritical speed6 NcCspeedRatedNhereNAC

BCRR

6

MODEL RAPHS:

DISCUSSION *UESTIONS:

1. 2efine critical speed and critical field resistance.#. *ist out the causes for the drop in terminal !oltae when enerator is loaded.$. ;hat are the effects of armature reactionT.

elect the meter ranes as per the specifications of $-"nduction motor.

RANE FIXIN:

The rane of 7oltmeter and mmeter can be fixed based on the !oltae andcurrent ratin of "nduction motor. &The "nduction motor can be loaded upto 1#,Jof Aull load capacity). The power factor of "nduction motor on Aull load is around ,.8.o6 B>A wattmeter can be chosen.PROCEDURE:

1.:n completion of circuit connection6 check for the motor is on

no-load condition6 close the T>T. #. rin the starter handle to T+T &or) Q position. llow the motor to pick

up speed.

$. Now brin the starter handle to +BN &or) position.

4.pply load in con!enient steps of mps6 till 1#,J of rated load and obser!e all meters readins6 force applied on brakedrum and speed.

NOTE::n no-load and liht loadin6 one of the wattmeter will i!e neati!e readin. :bser!e

these readins as minus readin by interchanin the terminals of current orpressure coil of that wattmeter.

O(SERVATION: 3A C 3A C

l.No.

7 " ;1 ;# peedN

Aorce Torque

N-m

"nput&;att

s)

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&rpm)

+eadin

>ower

&;atts)

+eadin

>ower

&;atts)

A

1

K

A

#

K

NetAorceACA1E

A#

lip:utput&;atts)

>ower factor 9fficiency

Mo$ C"c&"!io':

'ircumference of the brake drum C RRRRR cms

+adius of the brake drum6 r C RRRRR m

Torque applied on the shaft of the rotor6 T C &A1 E A#) r F.81 Nm

:utput power6 >o C

WattsNT.0

2

"nput power >i C ;1G ;#

J 9fficiency6 C

100i

o

P

P

>ower factor of motor C

IV

Pi

3

J slip C

speedsSynchronouNN

NNs

s

S=

6100

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or=ue

S96>, 0

, >.., /L, N

O o

N

>..

/L


&'heck also the power factor cos from the two wattmeter readins where

+

=

)(

)(3tan

12

121

WW

WW

P ;#S iher readin watt meter6 ;1S *ower readin

watt meter.)

MODEL RAPHS:

DISCUSSION *UESTIONS:

1. Name the types of $-"nduction motor.

#. ;hich type of $-"nduction motor has hiher startin torqueower factor meter &5,,!6 1,) -$7oltmeter &,-0,,7) -$s

FORMULA

>ower6 P=3cos

;here cos is the power factor.

PROCEDURE 'onnections are made as per the circuit diaram.

fter the connections are checked6 ssupply switch is closed.

No load readins are taken.

RL "s added in steps and their correspondin !oltae current and power

factor readins are noted. The inducti!e load is added in steps and their correspondin !oltaes6

current and power factor readins are noted.

O(SERVATION:

S.No

VRN

VYN VBN IR IY IB Po%$rF"c!or

Ac!i7$ Po%$r R$"c!i7$ Po%$r

PRN PYN PBN QRN QYN QBN

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CIRCUIT DIARAM:

RESULTS:Thus the power is measured by usin three ammeter and

three !oltmeter method.

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POWER MEASUREMENT (? TWO WATTMETER METHODEXPERIMENT No.:

AIM:To measure the three phase power usin two wattmeter method.

APPARATUS RE*UIRED:

S.No A,,"r"!&s R"'#$ S,$cific"!io' *&"'!i!-

THEOR?:The power is enerally measured by usin wattmeter. *oically we may require

one wattmeter for measurin power in one phase and so we may require threewattmeters to measure power in three phases. ut it can be pro!ed that the power inany three phase load &balanced ? unbalanced W star? delta) can be measured by usin

only two wattmeters. wattmeter will ha!e current coil &'') and pressure coil &>'). The pressure coil

is also called !oltae coil. The current coils of the two wattmeters employed formeasurements are connected such that they carry any two line currents. The third linein which there is no current coil is called common line.

The !oltae coil of a wattmeter is connected between the line to which its currentcoil is connected and the common line. imilarly the !oltae coil of another wattmeter isconnected between the line to which its current coil is connected and the common line.

RELATION (ETWEEN POWER FACTOR AND WATTMETER READIN

CASE /:W"!!+$!$r R$"i'#s "r$ EB&"*et ;1 C;#>ower factor obtained is unity

CASE 2:

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Wh$' O'$ W"!!+$!$r R$"i'# is $ro>ower factor is ,.5

CASE 3:Wh$' O'$ W"!!+$!$r R$"i'# is N$#"!i7$>ower factor will be less than ,.5

CASE 4:Wh$' (o!h W"!!+$!$r R$"i'# is Posi!i7$>ower factor will be reater than ,.5

PROCEDURE:

1. 'onnections are i!en as per the circuit diaram#. "nitially the load is kept in :AA position$. Three-phase ' supply is switched :N by closin the T>T switch4. *oad is switched :N and the load current is set at a particular !alue

5. The wattmeter readins are noted for !arious !alues of load current0. The readins are tabulated

FORMULAE:

R$" ,o%$r P < W/ =W2

R$"c!i7$ ,o%$r * < 3 0W2 W/1

CIRCUIT DIARAM:

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TA(ULATION:

S.No

Lo"C&rr$'!0A+,s1

W"!!+$!$r r$"i'#s 0%"!!s1To!" ,o%$r

0%"!!s1W/

0MF< 1

W2

0MF< 1 P *O(S ACT ACT O(S

RESULT:Thus the three-phase power usin two-wattmeter method was measured.

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VOLT AMPERE CHARACTERISTICS OF PN )UNCTION DIODEEXPERIMENT No:

AIM:1. To plot 7" &!olt ampere) characteristics of silicon >N Lunction diode.#. To find the cut-in !oltae for the i!en silicon >N =unction diode.

$. To find static and dynamic resistances in both forward and re!erse biasconditions.

APPARATUS RE*UIRED:S.No

N"+$ of !h$co+,o'$'!

R"'#$>S,$cific"!i

o'

*&"'!i!-

1. +eulated powersupply

&,-$,) 1

#. >N Lunction diode "N 4,,/ 1

$. +esistors 1 KX 1

4. mmeter &,-1,,)m 1

&, S 5,,)Y 1

5. 7oltmeter &, - 5)7 1

&, - #,) 7 1

0. read oard andconnectin wires

- -

THEOR?2onor impurities &penta!alent) are introduced into one-side and acceptor

impurities into the other side of a sinle crystal of an intrinsic semiconductor to form a p-

n diode with a =unction called depletion reion &this reion is depleted off the charecarriers). This reion i!es rise to a potential barrier 7Zcalled C&!@ i' Vo!"#$. This isthe !oltae across the diode at which it starts conductin. The >-N =unction can conductbeyond this >otential.

The >-N =unction supports uni-directional current flow. "f G!e terminal of the inputsupply is connected to anode &>-side) and S!e terminal of the input supply is connectedto cathode &N- side)6 then diode is said to be forward biased. "n this condition the heihtof the potential barrier at the =unction is lowered by an amount equal to i!en forwardbiasin !oltae. oth the holes from p-side and electrons from n-side cross the =unctionsimultaneously and constitute a forward current & i';$c!$ +i'ori!- c&rr$'!S due toholes crossin the =unction and enterin N-side of the diode6 due to electrons crossin

the =unction and enterin >-side of the diode).ssumin current flowin throuh the diode to be !ery lare6 the diode can beapproximated as short-circuited switch. "f S!e terminal of the input supply is connectedto anode &p-side) and G!e terminal of the input supply is connected to cathode &n-side)then the diode is said to be re!erse biased. "n this condition an amount equal to re!ersebiasin !oltae increases the heiht of the potential barrier at the =unction. oth theholes on p-side and electrons on n-side tend to mo!e away from the =unction therebyincreasin the depleted reion. owe!er the process cannot continue indefinitely6 thus a

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small current called r$7$rs$ s"!&r"!io' c&rr$'! continues to flow in the diode. Thissmall current is due to thermally enerated carriers. ssumin current flowin throuhthe diode to be neliible6 the diode can be approximated as an open circuited switch.

The !olt-ampere characteristics of a diode explained by followin equationD" C "o&9xp&7? [7T)-1)

"Ccurrent flowin in the diode"oCre!erse saturation current7C!oltae applied to the diode7TC!olt-equi!alent of temperatureCkT?qCT?1160,,C#0m7&\ room temp).[C1 &for e) and # &for i)

"t is obser!ed that e diode has smaller cut-in-!oltae when compared to idiode. The re!erse saturation current in e diode is larer in manitude whencompared to silicon diode.

>-N =unctions are elementary ]buildin blocks] of almost all semiconductorelectronic de!ices such as diodes6 transistors6 solar cells6 *92s6 and interated circuitsP

they are the acti!e sites where the electronic action of the de!ice takes place. Aorexample6 a common type of transistor6 the bipolar =unction transistor6 consists of two pSn

=unctions in series6 in the form nSpSn or pSnSp.

The disco!ery of the pSn =unction is usually attributed to merican physicist+ussell :hl of ell *aboratories.

Th$ s-+o for " io$ co+,"r$ !o "' "c!&" io$,"c9i'#

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CIRCUIT DIARAM:

1. A:+;+2 "D

#. +979+9 "D

PRECAUTIONS:1. ;hile doin the experiment do not exceed the ratins of the diode. This maylead to damae of the diode.#. 'onnect !oltmeter and mmeter in correct polarities as shown in the circuit

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diaram.$. 2o not switch ON the power supply unless you ha!e checked the circuitconnections as per the circuit diaram.

PROCEDURE:

For%"r (i"s$ Co'i!io':1. 'onnect the >N Lunction diode in forward bias i.enode is connected to positi!e

of the power supply and cathode is connected to neati!e of the power supply .#. Bse a +eulated power supply of rane &,-$,)7 and a series resistance of 1k^.$. t the cut-in !oltae &about ./ 7) the diode starts conductin.4. nd then increase forward !oltae further in steps and note down its

correspondin current readins &"f).

R$7$rs$ i"s$ co'i!io':1. 'onnect the >N Lunction diode in +e!erse bias i.eP anode is connected to

neati!e of the power supply and cathode is connected to positi!e of the power

supply.#. Aor !arious !alues of re!erse !oltae &7r ) note down the correspondin !alues

of re!erse current & "r ).

T"&"r co&+':

For%"r (i"s:

S. No Vf 07o!s1 If 0+A1

R$7$rs$ (i"s:

S. No Vr07o!s1 Ir0A1

r",h 0 i's!r&c!io's1

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1. Take a raph sheet and di!ide it into 4 equal parts. 3ark oriin at the center of theraph sheet.#. Now mark G!e x-axis as 7 fP -!e x-axis as 7rP G!e y-axis as "f P and -!e y-axis as " r.$. 3ark the readins tabulated for diode forward biased condition in first _uadrantand diode re!erse biased condition in third _uadrant.

r",h:C"c&"!io's fro+ r",h:tatic forward +esistance +dc C 7f?"f 2ynamic forward +esistance rac C `7f?`"f tatic +e!erse +esistance +dc C7r?"r 2ynamic +e!erse +esistance rac C `7r? "r

MODEL RAPH:

PRE@LA( *UESTIONS:

1. ow depletion reion is formed in the >N =unctionN =unction diode. The !oltae applied to the diode is !ariedby suitably !aryin the potentiometer. t some particular !alue of !oltae6 current startsflowin in th circuit. Then the applied !oltae is further increased in small steps and thecorrespondin !alues of diode forward current is noted and tabulated. The raph isdrawn between forward !oltae and forward current.R$7$rs$ Ch"r"c!$ris!ics:The connections are shown in Aiure #. The !oltae applied to the diode is !aried bysuitably !aryin the potentiometer. ;hen the %ener diode breaks down6 the ener!oltae remains nearly constant inspite of increase in applied !oltae. The maximumlimit of the re!erse current should not exceed it(s maximum limit. Then the readins ofener !oltae and diode current are measured and tabulated. The raph is drawntakin re!erse !oltae alon neati!e I-axis and re!erse diode current alon neati!eQ-axis.

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T"&"!io':

A:+;+2 " +979+9 "

7A&7) "A&m) 7+&7) "+&m)

Mo$ r",h:

;here6

7' C 'ut in 7oltae or Threshold 7oltae7+C +e!erse reakdown 7oltae7AC Aorward 7oltae7+C +e!erse 7oltae"AC Aorward'urrent"+C +e!erse 'urrent

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C"c&"!io':

The forward resistance6 +A can be calculated by +AC `7A `"A

The re!erse resistance6 ++can be calculated by ++C `7+ `"+

;here6`7AC 'hane in forward !oltae &7)`"AC 'hane in forward current &)`7+C 'hane in re!erse !oltae &7)`"+C 'hane in re!erse current &)

R$s&!:

Thus the static characteristics of ener 2iode is studied experimentally and the !aluesof forward resistance and re!erse resistances are calculated.

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9xperiment authoured by atha +abi6 > &.)? 999CHARACTERISTICS OF COMMON EMITTER AMPLIFIER

EXPERIMENT No:

AIM:

To determine the input and output characteristics of the i!en transistor in thecommon emitter confiuration.

APPARATUS RE*UIRED:

S.No

N"+$ of !h$ co+,o'$'! R"'#$ >S,$cific"!io'

*&"'!i!-

1. LT ' 14/ 1

#. 2' 7oltmeter source &, - $,) 7 #

$. 7oltmeter &, S $,) 7 1

&, S #)7 1

4. mmeter &, S $,,) m 1

&, S 5,,) Y 1

5. +heostat

0. read oard and 'onnectin

wires

THEOR?:

transistor consists of two >N =unctions formed by sandwichin either >-Type orN-Type semiconductor between two layers of the opposite type. The transistor has threereions namely6 9mitter6 ase and 'ollector.

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"n this confiuration6 the input is applied between the base and the emitter. Theemitter of the transistor is common to both input and output circuits. The sets ofcharacteristic cur!es6 referred to as the input characteristics and output characteristicsfor the !arious confiurations are important from practical considerations.

The input characteristic is the cur!e between the base emitter !oltae6 7 9andbase current "at constant collector emitter !oltae 7'9. The output characteristic is the

cur!e between collector current6 "'and collector emitter !oltae6 7'9at constant basecurrent ".CIRCUIT DIARAM:

PIN ASSINMENT:

PROCEDURE:"N>BT '+'T9+"T"'D

1. The connections are made as shown in the circuit diaram.

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#. The !oltae across the base and the emitter is !aried in steps keepin the

!oltae across the collector and the emitter constant.$. There exists a threshold or knee !oltae 7Kbelow which the base current is !ery

small.4. eyond the knee !oltae6 "increases with the increase in base to emitter

!oltae6 for a constant collector to emitter !oltae 7'9.5. The procedure is repeated for !arious constant !alues of 7'9.0. The readins are noted and tabulated.

:BT>BT '+'T9+"T"'D1. The connections are made as shown in the circuit diaram#. "n the output characteristic cur!e we can identify three reions namely saturation6

acti!e and cut-off reion.$. The base current "is kept constant and the !oltae across the 'ollector and the

emitter 7'9is !aried in steps.4. The correspondin collector current "'is noted and the readins are tabulated.

5. s 7'9is increased abo!e %ero6 the "'increases rapidly to a saturation !alue6when 7'9is increased further "' increases slihtly.

0. ;hen "is %ero6 a small "'exists this is called leakae current./. The procedure is repeated for !arious !alues of 7'9but constant !alues of ".

MODEL RAPH:

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TA(ULATION:INPUT CHARACTERISTICS:COLLECTOR TO EMITTER VOLTAE

VCE< GVCOLLECTOR TO EMITTER VOLTAE

VCE< 2.5> 5VS.No

("s$ !oE+i!!$r

Vo!"#$ V(E0V1

("s$ C&rr$'!I(0+A1

S.No

("s$ !oE+i!!$r

Vo!"#$ V(E0V1

("s$ C&rr$'!I(0+A1

OUTPUT CHARACTERISTICS:

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(ASE CURRENTI(< G.GJ +A

(ASE CURRENTI(< G./2 +A

S.No

Co$c!or !oE+i!!$r

Vo!"#$ VCE0V1

Co$c!orC&rr$'!

IC0+A1

S.No

Co$c!or !oE+i!!$r

Vo!"#$ VCE0V1

Co$c!orC&rr$'!

IC0+A1

PRELA( *UESTIONS:

/. M$'!io' "' ",,ic"!io' of Tr"'sis!or.2. Wh- is !h$ E+i!!$r +or$ '"rro%$r !h"' !h$ Co$c!orQ

Pr$c"&!io's:1. ;hile doin the experiment do not exceed the ratins of the transistor. This may

lead to damae the transistor.

#. 'onnect !oltmeter and mmeter in correct polarities as shown in the circuitdiaram.

$. 2o not switch ON the power supply unless you ha!e checked the circuitconnections as per the circuit diaram.

4. 3ake sure while selectin the emitter6 base and collector terminals of thetransistor.

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CHARATERISTICS OF FET AMPLIFIEREXPERIMENT No.:

Ai+:

To draw the drain and transfer characteristics of LA9T and find the rid resistance and

mutual conductance of the amplifier.

A,,"r"!&s R$B&ir$:

S.No N"+$ of !h$ Co+,o'$'! R"'#$ *&"'!i!-1+ LA9T 1

2+ 7oltmeter &,-$,)76 &,-#)7 3' 1 each

3+ +esistors #

7+ +eulated >ower upply &,-$,)7 2' 1

8+ mmeters &,-5,)3a6 3' 1

.+ +heostat 1.4K6 ,.0 1

Circ&i! Di"#r"+:

PIN CONFIURATION:

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THEOR?:The ;&'c!io' #"!$ fi$@$ff$c! !r"'sis!or &)FET or )UFET) is the simplest

type of field effect transistor. "t can be used as an electronically-controlled switch or as a!oltae-controlled resistance. 9lectric chare flows throuh a semiconductin channelbetween ]source] and ]drain] terminals. y applyin a bias !oltae to a ]ate] terminal6the channel is ]pinched]6 so that the electric current is impeded or switched offcompletely.

I!ss!r&c!&r$ isB&i!$si+,$. I' "N ch"''$)FET " N !-,$ siico'"rr$f$rr$ !o

"s !h$ch"''$h"s !%os+"$r

,i$c$s of P !-,$ siico' +"!$ri" iff&s$ o' !h$ o,,osi!$ si$s of i!s +i$ ,"r!for+i'# PN ;&'c!io's. Th$ !%o PN ;&'c!io' for+i'# io$s or #"!$s "r$co''$c!$ i'!$r'"- "' " co++o' !$r+i'" c"$ !h$ #"!$ !$r+i'" is roh!

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o&!. Oh+ic co'!"c!s 0ir$c! $$c!ric" co''$c!io's "r$ +"$ "! !h$ 2 $'s of !h$ch"''$ o'$ $" is c"$ !h$ so&rc$ !$r+i'" S "' !h$ o!h$r r"i' !$r+i'" D.

"n a =unction field-effect transistor6 or LA9T6 the controlled current passes fromsource to drain6 or from drain to source as the case may be. The controllin !oltae isapplied between the ate and source. Note how the current does not ha!e to crossthrouh a >N =unction on its way between source and drainD the path &called a channel)

is an uninterrupted block of semiconductor material. "n the imae =ust shown6 thischannel is an N-type semiconductor.

LA9T operation is like that of a arden hose. The flow of water throuh a hosecan be controlled by squee%in it to reduce the cross sectionP the flow of electric charethrouh a LA9T is controlled by constrictin the current-carryin channel. The currentalso depends on the electric field between source and drain &analoous to thedifference in pressureon either end of the hose).

SCHEMATIC DIARAM:

Pr$c"&!io's:1. ;hile doin the experiment do not exceed the ratins of the A9T. This may leadto damae the A9T.#. 'onnect !oltmeter and mmeter in correct polarities as shown in the 'ircuitdiaram.

$. 2o not switch :N the power supply unless you ha!e checked the 'ircuitconnections as per the circuit diaram.4. 3ake sure while selectin the ource6 2rain and ate terminals of the A9T.

PROCEDURE:

DRAIN CHARACTERISTICS

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http://en.wikipedia.org/wiki/Garden_hosehttp://en.wikipedia.org/wiki/Cross_section_(geometry)http://en.wikipedia.org/wiki/Electric_chargehttp://en.wikipedia.org/wiki/Fluid_pressurehttp://en.wikipedia.org/wiki/Fluid_pressurehttp://en.wikipedia.org/wiki/Cross_section_(geometry)http://en.wikipedia.org/wiki/Electric_chargehttp://en.wikipedia.org/wiki/Fluid_pressurehttp://en.wikipedia.org/wiki/Garden_hose


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1. 'onnections are i!en as per circuit diaram.#. The !alue of 7 is kept constant at a particular !alue.$. The !oltae 72is !aried in steps and correspondin "2is noted and readins are

tabulated.4. The same procedure is repeated for different but constant !alues of 7.5. >lot its characteristics with respect to 72 !ersus "2

TRANSFER CHARACTERISTICSD1. 'onnections are i!en as per circuit diaram.#. The 72is kept constant at a particular !alue.$. The 7is !aried in steps6 and correspondin "2is noted6 and readins are

tabulated.4. The same procedure is repeated for different constant !alues of 72.

r",h 0I's!r&c!io's1:

1. >lot the drain characteristics by takin 72on I-axis and "2 on Q-axis atconstant 7.#. >lot the Transfer characteristics by takin 7on I-axis and "2 on Q-axis atconstant 72.

C"c&"!io's fro+ r",h:

Dr"i' R$sis!"'c$ 0r1 :

"t is i!en by the ration of small chane in drain to source !oltae &`7 2) to

the correspondin chane in 2rain current &`"2) for a constant ate to source !oltae&7)6 when the LA9T is operatin in pinch-off or saturation reion.

Tr"'s@Co'&c!"'c$ 0#+1 :

+atio of small chane in drain current &`"2) to the correspondin chane inate to source !oltae &`7) for a constant 72. mC "2? `7at constant 72.&from transfer characteristics) The !alue of m is expressed in mho(s or siemens &s).

A+,ific"!io' F"c!or 01 :

"t is i!en by the ratio of small chane in drain to source!oltae &`72) to the correspondin chane in ate to source!oltae &`7) for a constant drain current. C `72? `7. C &`72? "2) I &`"2? `7) C rdI m.

I'f$r$'c$:

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1. s the ate to source !oltae &7) is increased abo!e %ero6 pinch off !oltae isincreased at a smaller !alue of drain current as compared to that when 7 C, 7#. The !alue of drain to source !oltae &72) is decreased as compared to that when7C,7$.The "2 increases rapidly as 72 "ncreases. This is due to the breakdown ofbreakdown of ate to source =unction due to a!alanche effect. "n transfer characteristics

it decreases.

R$s&!:

1. 2rain +esistance &rd) C .#. Transconductance &m) C .$. mplification factor &) C

Vi7" *&$s!io's:

1. ;hat is trans conductance # then ate current &") is kept constant. The !oltae between anode and cathode is increased in step bystep by !aryin the +> 1. The correspondin anode current &") is noted. The process is repeated for two more constant !alue of "6 thereadins are tabulated.

TA(ULATION:

S. No. A'o$ C"!ho$ Vo!"#$

i' Vo!s 0VAK1

"!$ C&rr$'! 0I1 A'o$ C&rr$'! 0IA1

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RESULT:

PRE LA( *UESTIONS:

1.;hat are the conditions for operatin a thyristor in the normal operation

Documents

Eeb 1282 Circuits Mchs and Devices Lab - Fair Try 1 (1)_1458750943725