Download - Electronis Circuits Lab 1
-
8/11/2019 Electronis Circuits Lab 1
1/45
SRINIVASAN ENGINEERING COLLEGE
DEPT OF ELECTRONICS AND COMMUNICATION ENGINEERING
ANNA UNIVERSITY CHENNAI
REGULATION 2009
II YEAR/ III SEMESTER
EC2208 ELECTONICS CIRCUITS LABORATORY-I
LABMANUAL
ISSUE:01 REVISION:00
APPROVED BY PREPARED BY
Prof. B. REVATHI R.SANKAR GANESH, AP.
HOD/ECE R.ANBARASAN, Assistant Professor.
-
8/11/2019 Electronis Circuits Lab 1
2/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 2
Preface
This laboratory manual is prepared by the Department of Electronics and communication
engineering for Circuits and Devices (EC2155). This lab manual can be used as instructional book for
students, staff and instructors to assist in performing and understanding the experiments. This manual
will be available in electronic form from Colleges official website, for the betterment of students.
Acknowledgement
We would like to express our profound gratitude and deep regards to the support offered by
the Chairman Shri. A.Srinivasan. We also take this opportunity to express a deep sense of
gratitude to our Principal Dr.B.Karthikeyan,M.E, Ph.D, for his valuable information and
guidance, which helped us in completing this task through various stages. We extend our hearty
thanks to our head of the department Prof.B.Revathi M.E, (Ph.D),for her constant encouragement
and constructive comments.
Finally the valuable comments from fellow faculty and assistance provided by the
department are highly acknowledged.
-
8/11/2019 Electronis Circuits Lab 1
3/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 3
INDEX
S.No TOPIC PAGENO
1 Syllabus 4
2 Lab Course Handout 5
3 Basics for bread board connection 8
4 Experiments
1. Fixed Bias amplifier circuit using BJT 10
2. Design and construct BJT Common Emitteramplifier using voltage divider bias (self-bias) with
and without bypassed emitter resistor.
16
3. Design and construct BJT Common Collector Amplifier using voltage 23
4. Darlington Amplifier using BJT. 26
5. Source follower with Bootstrapped gate resistance 32
6. Differential amplifier using BJT
35
7. Class A Power Amplifier 44
8. Class B Complementary symmetry power amplifier 50
9. Power Supply circuit - Half wave rectifier withsimple capacitor filter.
54
10. Power Supply circuit - Full wave rectifier withsimple capacitor filter
63
5 76
-
8/11/2019 Electronis Circuits Lab 1
4/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 4
ELECTRONICS CIRCUITS LAB
SYLLABUS
Expt No.1 Fixed Bias amplifier circuit using BJT
1. Waveforms at input and output without bias.
2. Determination of bias resistance to locate Q-point at center of load line.
3. Measurement of gain.
4. Plot the frequency response & Determination of Gain Bandwidth Product
Expt No.2 Design and construct BJT Common Emitter Amplifier using voltage
divider bias (self-bias) with and without bypassed emitter resistor.
1. Measurement of gain.
2. Plot the frequency response & Determination of Gain Bandwidth Product
Expt No.3 Design and construct BJT Common Collector Amplifier using voltage
divider bias (self-bias).
1. Measurement of gain.2. Plot the frequency response & Determination of Gain Bandwidth Product
Expt No.4 Darlington Amplifier using BJT.
1. Measurement of gain and input resistance. Comparison with calculated values.
2. Plot the frequency response & Determination of Gain Bandwidth Product
Expt No.5 Source follower with Bootstrapped gate resistance
1. Measurement of gain, input resistance and output resistance with and without
Bootstrapping. Comparison with calculated values.
Expt No.6 Differential amplifier using BJT
1. Measurement of CMRR.
Expt No.7 Class A Power Amplifier
1.Observation of output waveform.
2.Measurement of maximum power output.
3.Determination of efficiency.
4.Comparison with calculated values.
Expt No.8 Class B Complementary symmetry power amplifier
1.Observation of the output waveform with crossover Distortion.
2.Modification of the circuit to avoid crossover distortion.
3.Measurement of maximum power output.
4.Determination of efficiency.
5.Comparison with calculated values.
Expt No.9 Power Supply circuit - Half wave rectifier with simple capacitor filter.
33
1. Measurement of DC voltage under load and ripple factor, Comparison withcalculated values.
2. Plot the Load regulation characteristics using Zener diode.
Expt No.10 Power Supply circuit - Full wave rectifier with simple capacitor filter
1. Measurement of DC voltage under load and ripple factor, Comparison with
calculated values.
2. Measurement of load regulation characteristics. Comparison with calculated values
-
8/11/2019 Electronis Circuits Lab 1
5/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 5
LAB COURSE HANDOUT
Subject code :EC 2208
Subject Title : ELECTRONICS CIRCUITS Lab
Staff name : R. SANKAR GANESH & R.ANBARASAN
Scope and Objective of the Subject:
To FIND THE GAIN OF BJT TRANSISTOR AND POWER AMPLIFIERS
Course Plan / Schedule:
S.No Topics to be covered Learning objectives Page
No*
No. of
hours
1 Fixed Bias amplifier circuit using BJT To design and construct a common
emitter amplifier with fixed bias,
measurement of gain and gain-
bandwidth product by plotting its
frequency response.
3 hrs
2 BJT COMMON EMITTERAMPLIFIER USINGVOLTAGE
DIVIDER BIAS
To design and construct a common
emitter amplifier with self bias,
measurement of gain and gain-
bandwidth product by plotting its
frequency response.
3hrs
3 BJT COMMON COLLECTORAMPLIFIER USING VOLTAGE
DIVIDER BIAS
To design and construct a common
collector amplifier with self bias,
measurement of gain and gain-
bandwidth product by plotting its
frequency response.
3hrs
4 DARLINGTON AMPLIFIER USINGBJT
To construct a Darlington current
amplifier circuit, determination of
gain and input resistance and to plot
the frequency response characteristics
3hrs
5 SOURCE FOLLOWER WITH BOOTSTRAPPED GATE RESISTANCE
To construct a source follower 3hrs
-
8/11/2019 Electronis Circuits Lab 1
6/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 6
bootstrapped gate resistance amplifier
circuit and to measure the input and
output resistances.
6 DIFFERENTIAL AMPLIFIERUSING BJT
To construct a differential amplifier usingBJT and to calculate the CMRR 3hrs
7 CLASS - A POWER AMPLIFIER To construct a class A amplifier and
absorb the waveform3hrs
8 CLASS B COMPLEMENTARYSYMMETRY POWERAMPLIFIER
To construct a CLASS B amplifier and
absorb the waveform3hrs
9 HALF WAVE RECTIFIER To construct a halfwave rectifier to plot
its input and output waveform3hrs
10 FULL WAVE RECTIFIER To construct a full wave rectifier andmeasure DC resistance under load
3hrs
11 3hrs
12 3hrs
*-As in Lab ManualEvaluation
schemeInternal AssessmentEC
No.
Evaluation
Components
Duration Weightage
1 Observation Continuous 20%
2 Record Continuous 30%
3 Attendance Continuous 30%
4 Model lab 3hr 20%
EC
No.
Evaluation
Components
Duration Weightage
1 Observation Continuous 20%
2 Record Continuous 30%
3 Attendance Continuous 30%
-
8/11/2019 Electronis Circuits Lab 1
7/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 7
Timings for chamber consultation: Students should contact the Course Instructor in her/his
chamber during lunch break.
STUDENTS GUIDELINES
There are 3 hours allocated to a laboratory session in Circuits and Devices Lab. It is a necessary
part of the course at which attendance is compulsory.
Here are some guidelines to help you perform the Programs and to submit the reports:
1. Read all instructions carefully and proceed according to that.
2. Ask the faculty if you are unsure of any concept.
3. Give the connection as per the diagrams.
4. After verification by the faculty, tabulate the readings.
5. Write up full and suitable conclusions for each experiment and draw the graph.
6. After completing the experiment complete the observation and get signature from the staff.
7. Before coming to next lab make sure that you complete the record and get sign from the
faculty.
STAFF SIGNATURE HOD
-
8/11/2019 Electronis Circuits Lab 1
8/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 8
BREADBOARD
The breadboard consists of two terminal strips and two bus strips (often broken in the
centre). Each bus strip has two rows of contacts. Each of the two rows of contacts are a node.
That is, each contact along a row on a bus strip is connected together (inside the breadboard). Busstrips are used primarily for power supply connections, but are also used for any node requiring a
large number of connections. Each terminal strip has 60 rows and 5 columns of contacts on each
side of the centre gap. Each row of 5 contacts is a node. You will build your circuits on the
terminal strips by inserting the leads of circuit components into the contact receptacles and
making connections with
Incorrect connection of power to the ICs could result in them exploding or becoming very
hot with the possible serious injury occurring to the people working on the experiment! Ensure
that the power supply polarity and all components and connections are correct before switching
on power .
Fig 1. The breadboard. The lines indicate connected holes.
-
8/11/2019 Electronis Circuits Lab 1
9/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 9
BUILDING THE CIRCUIT
The steps for wiring a circuit should be completed in the order described below:
1. Turn the power (Trainer Kit) off before you build anything!2. Make sure the power is off before you build anything!
3. Connect the supply and ground (GND) leads of the power supply to the power and ground
bus strips on your breadboard.
4. Plug the devices you will be using into the breadboard.
5. Mark each connection on your schematic as you go, so as not to try to make the same
connection again at a later stage.
6. Get one of your group members to check the connections, before you turn the power on.
7. If an error is made and is not spotted before you turn the power on. Turn the power off
immediately before you begin to rewire the circuit.
8. At the end of the laboratory session, collect you hook-up wires, devices and all equipment
and return them to the demonstrator.
9. Tidy the area that you were working in and leave it in the same condition as it was before
you started.
Common Causes of Problems:
1. Not connecting the ground and/or power pins.
2. Not turning on the power supply before checking the operation of the circuit.
3. Leaving out wires.
4. Plugging wires into the wrong holes.
5. Modifying the circuit with the power on.
In all experiments, you will be expected to obtain all instruments, leads, components at
the start of the experiment and return them to their proper place after you have finished the
experiment. Please inform the demonstrator or technician if you locate faulty equipment.
-
8/11/2019 Electronis Circuits Lab 1
10/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 10
1.FIXEDBIASAMPLIFIERCIRCUIT
1.1.AIM:
Toconstructafixedbiasamplifiercircuitandtoplotthefrequencyresponsecharacteristics.
1.2APPARATUSREQUIRED:
S.No. Name Range Quantity1. Transistor BC107 12. Resistor 10 k,100 k,680 1,1,13. Regulated power supply (0-30)V 14. Signal Generator (0-3)MHz 15. CRO 30 MHz 16. Bread Board 17. Capacitor 47F 2
CIRCUITDIAGRAM
-
8/11/2019 Electronis Circuits Lab 1
11/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 11
MODELGRAPH
f 1 FIG.9.2 f2 f
(Hz)
TAB.1.1:
FREQUENCYRESPONSEOFFIXEDBIASAMPLIFIER
Keeptheinputvoltageconstant(Vin)=
Frequency (in Hz) Output Voltage (in volts) Gain = 20 log (Vo / Vin) (in dB)
1.3.FORMULA:
a) R2/(R1+R2)=voltageatwhichClassA,ClassBorClassC
operationtakesplace
-
8/11/2019 Electronis Circuits Lab 1
12/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 12
b) hfe=Ic/Ib
1.4.THEORY:
Inordertooperatethetransistorinthedesiredregion,wehavetoapplyanexternaldcvoltage
of correctpolarityandmagnitude to the twojunctionsof the transistor. This is called biasingof the
transistor.
Whenwebiasatransistor,weestablishcertaincurrentandvoltageconditionsforthetransistor.
These conditionsare called operating conditionsordc operating point or quiescent point. This point
mustbestableforproperoperationoftransistor.Animportantandcommontypeofbiasing iscalled
FixedBiasing.Thecircuitisverysimpleandusesonlyfewcomponents.Butthecircuitdoesnotcheck
thecollectorcurrentwhichincreaseswiththeriseintemperature.
1.5.PROCEDURE
1. Connectionsaremadeasperthecircuitdiagram.
2. The waveforms at the input and output are observed for Class A, Class B and Class C
operationsbyvaryingtheinputvoltages.3. ThebiasingresistancesneededtolocatetheQ-pointaredetermined.
4. Settheinputvoltageas1Vandbyvaryingthefrequency,notetheoutputvoltage.
5. Calculategain=20log(Vo/Vin)
6. Agraphisplottedbetweenfrequencyandgain.
1.6.CALCULATIONS:
a) Todeterminethevalueofbiasresistace
R2/(R1+R2)
b) hfe=IC/IB
1.7.RESULT:
Thus,theFixedbiasamplifierwasconstructedandthefrequencyresponsecurveisplotted.The
GainBandwidthProductisfoundtobe=
-
8/11/2019 Electronis Circuits Lab 1
13/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 13
2.BJTAMPLIFIERUSINGVOLTAGEDIVIDERBIAS
2.1.AIM:
Toconstantavoltagedividerbiasamplifierandmeasureinputresistanceandgainandalsoto
plotthedccollectorcurrentasafunctionofcollectorresistance.
2.2.APPARATUSREQUIRED:
S.No. Name Range Quantity
1. Transistor BC 107 12. Resistor 56k,12k,2.2k,470 1,1,1,1
3. Capacitor 0.1F, 47F 2, 14. Function Generator (0-3)MHz 1
5. CRO 30MHz 1
6. Regulated power supply (0-30)V 1
7. Bread Board 1
FIG.5.1
-
8/11/2019 Electronis Circuits Lab 1
14/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 14
MODELGRAPH
f 1 FIG..2 f2 f (Hz)
TAB2.1:
Keeptheinputvoltageconstant,Vin=
Frequency (in Hz) Output Voltage (in volts) Gain= 20 log(Vo/Vin) (in dB)
2.3.FORMULA:
a) Rin=*Re
b) Gain=*Re/Rin
-
8/11/2019 Electronis Circuits Lab 1
15/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 15
2.4.THEORY:
ThistypeofbiasingisotherwisecalledEmitterBiasing.Thenecessarybiasingisprovidedusing3
resistors:R1,R2andRe.TheresistorsR1andR2actasapotentialdividerandgiveafixedvoltagetothebase.Ifthecollectorcurrentincreasesduetochangeintemperatureorchangein,theemittercurrent
Ie also increasesandthevoltagedropacrossRe increases,reducingthevoltagedifferencebetweenthe
baseandtheemitter.DuetoreductioninVbe,basecurrentIb andhencecollectorcurrentIc alsoreduces.
Thisreduction inVbe,basecurrent Ib andhencecollectorcurrent Ic also reduces.Thisreduction in the
collectorcurrentcompensatesfortheoriginalchangeinIc.
ThestabilityfactorS=(1+)*((1/(1+)).Tohavebetterstability,wemustkeepRb/Re assmallas
possible.HencethevalueofR1R2mustbesmall.IftheratioRb/Reiskeptfixed,Sincreaseswith.
5.PROCEDURE:
1. Connectionsaregivenasperthecircuitdiagram.
2. Measure the input resistance as Rin=Vin/Iin (with output open) and gain by plotting the
frequencyresponse.
3. Comparethetheoreticalvalueswiththepracticalvalues.
4. Plotthedccollectorcurrentasafunctionofthecollectorresistance(ie)plotofVcc andIc for
variousvaluesofRe.
2.6.RESULT:
Thus the voltage divider bias amplifier was constructed and input resistance and gain were
determined.TheGainBandwidthProductisfoundtobe=
-
8/11/2019 Electronis Circuits Lab 1
16/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 16
3.COMMONCOLLECTORAMPLIFIER
3.1AIM:
To construct a common collector amplifier circuit and to plot the frequency response
characteristics.
3.2.APPARATUSREQUIRED:
S.No. Name Range Quantity
1. Transistor BC 107 12. Resistor 15k
,10k
,680
,6k
1,1,1,13. Capacitor 0.1F, 47F 2, 14. Function Generator (0-3)MHz 15. CRO 30MHz 16. Regulated power supply (0-30)V 17. Bread Board 1
CIRCUITDIAGRAM
-
8/11/2019 Electronis Circuits Lab 1
17/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 17
MODELGRAPH
f 1 FIG..2 f2 f (Hz)
TAB3.1:
Keeptheinputvoltageconstant,Vin=
Frequency (in Hz) Output Voltage (in volts) Gain= 20 log(Vo/Vin) (in dB)
-
8/11/2019 Electronis Circuits Lab 1
18/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 18
3.3THEORY:
Thed.cbiasingincommoncollectorisprovidedbyR1,R2andRE.Theloadresistanceiscapacitor
coupledtotheemitterterminalofthetransistor.
Whenasignalisappliedtothebaseofthetransistor,VBisincreasedanddecreasedasthe
signalgoespositiveandnegative,respectively.ConsideringVBE isconstantthevariationintheVB
appearsattheemitterandemittervoltageVEwillvarysameasbasevoltageVB.Sincetheemitteris
outputterminal,itcanbenotedthattheoutputvoltagefromacommoncollectorcircuitisthesameas
itsinputvoltage.Hencethecommoncollectorcircuitisalsoknownasanemitterfollower.
3.5PROCEDURE:
1.Connectthecircuitasperthecircuitdiagram.
2.SetVi=50mV,usingthesignalgenerator.
3.Keepingtheinputvoltageconstant,varythefrequencyfrom0Hzto1MHzinregularstepsandnote
downthecorrespondingoutputvoltage.
4.Plotthegraph;Gain(dB)Vs Frequency(Hz).
REVIEWQUESTIONS:
1.Whythecommoncollectoramplifierisalsocalledanemitterfollower?
2.Whatistheneedforcouplingcapacitors?
3.Whatwillbetheinput&outputimpedanceofcommoncollectoramplifier?
4.Writesomeapplicationsof commoncollectoramplifier.
5.Whatisthecurrentamplificationfactorofcommoncollector amplifier?
3.6.RESULT:
Thus, the Common collector amplifier wasconstructed and the frequency response curve is
plotted.TheGainBandwidthProductisfoundtobe=
-
8/11/2019 Electronis Circuits Lab 1
19/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 19
4.DARLINGTONAMPLIFIERUSINGBJT
4.1AIM:
To construct a Darlington current amplifier circuit and to plot the frequency response
characteristics.
4.2.APPARATUSREQUIRED:
S.No. Name Range Quantity1. Transistor BC 107 1
2. Resistor 15k
,10k
,680
,6k
1,1,1,13. Capacitor 0.1F, 47F 2, 14. Function Generator (0-3)MHz 15. CRO 30MHz 16. Regulated power supply (0-30)V 17. Bread Board 1
CIRCUITDIAGRAM
-
8/11/2019 Electronis Circuits Lab 1
20/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 20
MODELGRAPH
f 1 FIG..2 f2 f (Hz)
TAB4.1:
Keeptheinputvoltageconstant,Vin=
Frequency (in Hz) Output Voltage (in volts) Gain= 20 log(Vo/Vin) (in dB)
-
8/11/2019 Electronis Circuits Lab 1
21/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 21
THEORY:
In Darlingtonconnectionoftransistors,emitterofthefirsttransistorisdirectlyconnectedto
thebaseofthesecondtransistor.Becauseof directcouplingdcoutputcurrentofthefirststageis(1+hfe
)Ib1.If Darlingtonconnection for n transitor isconsidered, then due todirectcoupling thedcoutput
current foe laststage is (1+hfe )n times Ib1 .Due to very large amplification factor even two stage
Darlingtonconnectionhaslargeoutputcurrentandoutputstagemayhavetobeapowerstage.Asthe
poweramplifiersarenotusedintheamplifiercircuitsitisnotpossibletousemorethantwotransistors
intheDarlingtonconnection.
InDarlingtontransistorconnection,theleakagecurrentofthefirsttransistorisamplifiedbythe
secondtransistorandoverallleakagecurrentmaybehigh,Whichisnotdesired.
4.4PROCEDURE:
1.Connectthecircuitasperthecircuitdiagram.
2.SetVi=50mv,usingthesignalgenerator.
3.Keepingtheinputvoltageconstant,varythefrequencyfrom0Hzto1MHzinregularstepsandnote
downthecorrespondingoutputvoltage.
4.Plotthegraph;Gain(dB)vs Frequency(Hz).
5.Calculatethebandwidthfromthegraph.
4.5.RESULT:
Thus, theDarlington current amplifier was constructed and the frequency responsecurve is
plotted..TheGainBandwidthProductisfoundtobe=
REVIEWQUESTIONS:
1. WhatismeantbyDarlingtonpair?
2.HowmanytransistorsareusedtoconstructaDarlingtonamplifiercircuit?
3.WhatistheadvantageofDarlingtonamplifiercircuit?
4.Writesomeapplicationsof Darlingtonamplifier.
-
8/11/2019 Electronis Circuits Lab 1
22/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 22
5.SOURCEFOLLOWERWITHBOOTSTRAPPEDGATERESISTANCE
5.1.AIM:
To construct a source follower with bootstrapped gate resistance amplifier and plot its
frequencyresponsecharacteristics.
5.2.APPARATUSREQUIRED:
S.No. Name Range Quantity
1. Transistor BC107 2
2. Resistor 1k,11k,1Mk 1,1,1
3. Regulatedpowersupply (0-30)V 1
4. SignalGenerator (0-3)MHz 1
5. CRO 30MHz 1
6. BreadBoard 1
7. Capacitor 0.01F 2
FIG.13.1
-
8/11/2019 Electronis Circuits Lab 1
23/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 23
MODELGRAPH
f 1 f2 f (Hz)
FIG.13.2
TAB.5.1.
Keeptheinputvoltageconstant(Vin)=
frequency (in Hz) Output Voltage (in volts)
Gain = 20 log (Vo / Vin) (in dB)
-
8/11/2019 Electronis Circuits Lab 1
24/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 24
5.3.THEORY:
Source follower is similar to the emitter follower( the output source voltage follow the gate inputvoltage),the circuit has a voltage gain of less than unity, no phase reversal, high input impedance,low output impedance. Here the Bootstrapping is used to increase the input resistance byconnecting a resistance in between gate and source terminals.The resister RA is required to
develop the necessary bias for the gate.
5.4. PROCEDURE:
1.Connectionsaremadeasperthecircuitdiagram.
2. The waveforms at the input and output are observed for cascode operations by
varying the input frequency.
3.ThebiasingresistancesneededtolocatetheQ-pointaredetermined.
4.Settheinputvoltageas1Vandbyvaryingthefrequency,notetheoutputvoltage.
5.Calculategain=20log(Vo/Vin.)
6.Agraphisplottedbetweenfrequencyandgain.
RESULT:
Thus,theSourcefollowerwithBootstrappedgateresistancewasconstructedandthegainwas
determined.
REVIEWQUESTIONS:
1. Whatismeantbysourcefollower?
2. WhatismeantbyBootstrapping?
3. Howtheabovecircuit isusedtoprovideagoodimpedancematching?
. Whatistheadvantageofbootstrappingmethod?
-
8/11/2019 Electronis Circuits Lab 1
25/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 25
6.DIFFERENTIALAMPLIFIERUSINGBJT
6.1Aim: To construct adifferential amplifier usingBJT and to determine thedc collector currentof
individualtransistorsandalsotocalculatetheCMRR.
6.2.APPARATUSREQUIRED:
S.No. Name Range Quantity1. Transistor BC107 22. Resistor 4.7k, 10k 2,13. Regulated power supply (0-30)V 14. Function Generator (0-3) MHz 25. CRO 30 MHz 1
6. Bread Board 1
CIRCUITDIAGRAM
OBSERVATION
VIN=VO=AC= VO/VIN
-
8/11/2019 Electronis Circuits Lab 1
26/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 26
FORMULA:
CommonmodeGain (Ac)=VO/VIN
DifferentialmodeGain(Ad)=V0/VIN
WhereVIN=V1V2
CommonModeRejectionRatio(CMRR)=Ad/Ac
Where,Adisthedifferentialmodegain
Ac isthecommonmodegain.
THEORY:
The differential amplifier is a basic stage of an integrated operational amplifier. It is used to
amplifythedifferencebetween2signals.Ithasexcellentstability,highversatilityandimmunitytonoise.
Inapracticaldifferentialamplifier,theoutputdependsnotonlyuponthedifferenceofthe2signalsbut
alsodependsuponthecommonmodesignal.
TransistorQ1andQ2havematchedcharacteristics.ThevaluesofRC1 andRC2 areequal.Re1 and
Re2 are also equal and this differential amplifier is called emitter coupled differential amplifier. The
outputistakenbetweenthetwooutputterminals.
-
8/11/2019 Electronis Circuits Lab 1
27/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 27
OBSERVATION
VIN=V1V2
V0=
Ad=V0/VIN
For thedifferentialmodeoperation the input is taken from two differentsourcesand thecommon
modeoperationtheappliedsignalsaretakenfromthesamesource
CommonModeRejectionRatio(CMRR)isanimportantparameterofthedifferentialamplifier.
CMRRisdefinedastheratioofthedifferentialmodegain,Adtothecommonmodegain,Ac.
CMRR=Ad/Ac
Inidealcases,thevalueofCMRRisveryhigh.
-
8/11/2019 Electronis Circuits Lab 1
28/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 28
6.5.PROCEDURE:
1. Connectionsaregivenasperthecircuitdiagram.
2. Todeterminethecommonmodegain,wesetinputsignalwithvoltageVin=2V
anddetermineVoatthecollectorterminals.Calculatecommonmodegain,Ac=Vo/Vin.
3. To determine the differential mode gain, we set input signals with voltages V1 and V2.
Compute Vin=V1-V2 and find Vo at the collector terminals. Calculate differential mode
gain,Ad=Vo/Vin.
4. CalculatetheCMRR=Ad/Ac.5. Measurethedccollectorcurrentfortheindividualtransistors.
6.6.RESULT:
Thus, the Differential amplifier was constructed and dc collector current for the individual
transistorsisdetermined.TheCMRRiscalculatedas
REVIEWQUESTIONS
1.Whatisadifferentialamplifier?
2.Whatiscommonmodeanddifferentialmodeinputsinadifferentialamplifier?
3.DefineCMRR.
4.Whatiscommonmodesignal?
5. WritesomeapplicationsofDifferentialamplifier.
-
8/11/2019 Electronis Circuits Lab 1
29/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 29
7.CLASS-APOWERAMPLIFIER
7.1.AIM:
ToconstructaClassApoweramplifierandobservethewaveformandtocomputemaximum
outputpowerandefficiency.
7.2.APPARATUSREQUIRED:
S.No. Name Range Quantity1. Transistor CL100, BC558 1,12. Resistor 47k ,33 ,220, 2,13. Capacitor 47 F 24. Signal Generator (0-3)MHz 15. CRO 30MHz 16. Regulated power supply (0-30)V 17. Bread Board 1
CIRCUITDIAGRAM
-
8/11/2019 Electronis Circuits Lab 1
30/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 30
o L
TAB2.1:
Keeptheinputvoltageconstant,Vin=
Frequency (in Hz) Output Voltage (in volts) Gain= 20 log(Vo/Vin) (in dB)
7.3.FORMULA
Maximumpowertransfer=Po,max=V2/R
Effeciency,=Po,max/Pc
7.4.THEORY:
Thepoweramplifier issaidtobe ClassAamplifieriftheQpointandtheinputsignal
areselectedsuchthattheoutputsignalisobtainedforafullinputsignalcycle.
Forallvaluesofinputsignal,thetransistorremainsintheactiveregionandneverentersintocut-
-
8/11/2019 Electronis Circuits Lab 1
31/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 31
offorsaturationregion.Whenana.csignalisapplied,thecollectorvoltagevariessinusoidallyhence
the collectorcurrentalsovariessinusoidally.Thecollectorcurrentflowsfor3600 (fullcycle)oftheinput
signal.ietheangleofthecollectorcurrentflowis3600.
7.5PROCEDURE:
1.Connectthecircuitasperthecircuitdiagram.
2.SetVi=50mv,usingthesignalgenerator.
3.Keepingtheinputvoltageconstant,varythefrequencyfrom10Hzto1MHzinregularstepsandnote
downthecorrespondingoutputvoltage.
4.Plotthegraph;Gain(dB)vs Frequency(Hz).
7.6.RESULT:
ThustheClassApoweramplifierwasconstructed.Thefollowingparameterswerecalculated:
a) Maximumoutputpower=
` b) Efficiency=
REVIEWQUESTIONS:
1. Whatismeantby PowerAmplifier?
2. WhatisthemaximumefficiencyinclassAamplifier.
3. WhatarethedisadvantagesofClassAamplifier?
4. WritesomeapplicationsofPoweramplifier.
5.WhatisthepositionofQ-pointinClassAamplifier?
-
8/11/2019 Electronis Circuits Lab 1
32/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 32
8.CLASSBCOMPLEMENTARYSYMMETRYPOWERAMPLIFIER
8.1.AIM:
ToconstructaClassBcomplementarysymmetrypoweramplifierandobservethewaveforms
withandwithoutcross-overdistortionandtocomputemaximumoutputpowerandefficiency.
8.2.APPARATUSREQUIRED:
S.No. Name Range Quantity1. Transistor CL100, BC558 1,12. Resistor 4.7k,15k 2,13. Capacitor 100F 24. Diode IN4007 25. Signal Generator (0-3)MHz 16. CRO 30MHz 17. Regulated power supply (0-30)V 18. Bread Board 1
CIRCUITDIAGRAM
-
8/11/2019 Electronis Circuits Lab 1
33/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 33
8.3.FORMULA:
Inputpower,Pin=2VccIm/
Outputpower,Pout=VmIm/2
PowerGainorefficiency,=/4(Vm/Vcc)100
8.4.THEORY:
ApoweramplifierissaidtobeClassBamplifieriftheQ-pointandtheinputsignalareselected
such that the output signal is obtained only for one half cycle for a full input cycle. The Q-point is
selectedontheX-axis.Hence,thetransistorremainsintheactiveregiononlyforthepositivehalfofthe
inputsignal.
There are two types of Class B power amplifiers: Push Pull amplifier and complementary symmetry
amplifier.In
the
complementary
symmetry
amplifier,
one
n-p-n
and
another
p-n-p
transistor
is
used.
Thematchedpairoftransistorareusedinthecommoncollectorconfiguration.Inthepositivehalfcycle
oftheinputsignal,then-p-ntransistorisdrivenintoactiveregionandstartsconductingandinnegative
halfcycle,thep-n-ptransistorisdrivenintoconduction.Howeverthereisaperiodbetweenthecrossing
ofthehalfcyclesoftheinputsignals,forwhichnoneofthetransistorisactiveandoutput,iszero
CIRCUITDIAGRAM
FIG.6.2
-
8/11/2019 Electronis Circuits Lab 1
34/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 34
OBSERVATION
OUTPUTSIGNAL
AMPLITUDE :
TIMEPERIOD :
CALCULATION
POWER,PIN =2VCCIm/
OUTPUTPOWER,POUT =VmIm/2
EFFICIENCY, =(/4)(Vm/VCC)x100
MODELGRAPH
FIG.6.3
-
8/11/2019 Electronis Circuits Lab 1
35/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 35
-
8/11/2019 Electronis Circuits Lab 1
36/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 36
8.5.PROCEDURE:1. Connectionsaregivenasperthecircuitdiagramwithoutdiodes.
2. Observe thewaveformsandnote theamplitudeand time periodof the inputsignaland
distortedwaveforms.
3.
Connectionsare
made
with
diodes.
4. Observe thewaveformsandnote theamplitudeand time periodof the inputsignaland
outputsignal.
5. Drawthewaveformsforthereadings.
6. Calculatethemaximumoutputpowerandefficiency.
Hence thenatureof theoutputsignalgetsdistortedandno longerremains thesameasthe
input.Thisdistortioniscalledcross-overdistortion.Duetothisdistortion,eachtransistorconductsfor
lessthanhalfcycleratherthanthecompletehalfcycle.Toovercomethisdistortion,weadd2diodesto
provideafixedbiasandeliminatecross-overdistortion.
8.6.RESULT:
ThustheClassBcomplementarysymmetrypoweramplifierwasconstructedtoobservecross-
over distortion and the circuit was modified to avoid the distortion. The following parameters were
calculated:
a)Maximumoutputpower=
b)Efficiency=
-
8/11/2019 Electronis Circuits Lab 1
37/45
ELECTRONICS LABI SRINIVASAN ENGINEERING COLLEGE PERAMBALUR/II YEAR, III SEM
ISSUE:01 REVISION:00 37
9.HALFWAVERECTIFIER
9.1.AIM:
To construct half wave rectifier with and without filter and to draw their input and outputwaveforms.
9.2.APPARATUSREQUIRED:
S.No. Name Range Quantity
1. Transformer 230V/6-0-(-6) 1
2. Diode IN4007 1
3. Resistor 1k 1
4. Capacitor 100F 1
5. CRO 30MHz 1
6. BreadBoard 1
CIRCUITDIAGRAM:
WITHOUTFILTER:
FIG.13.1
-
8/11/2019 Electronis Circuits Lab 1
38/45
CIRCUITS AND DEVICES LAB MANUAL
SRINIVASAN ENGINEERING COLLEGE, PERAMBALURI YEAR
ISSUE: 01 REVISION: 00 38
WITHFILTER:
FIG.13.2
9.3.FORMULAUSED:
RippleFactor=
WhereImisthepeakcurrent
9.4.THEORY:
Halfwaverectifier:
-
8/11/2019 Electronis Circuits Lab 1
39/45
CIRCUITS AND DEVICES LAB MANUAL
SRINIVASAN ENGINEERING COLLEGE, PERAMBALURI YEAR
ISSUE: 01 REVISION: 00 39
Arectifier isacircuit,whichusesoneormorediodestoconvertA.Cvoltage intoD.Cvoltage. Inthis
rectifierduringthepositivehalfcycleoftheA.Cinputvoltage,thediodeisforwardbiasedandconducts
for all voltages greater than the offset voltage of the semiconductor material used. The voltage
producedacrossthe loadresistorhassameshapeasthatofthepositive inputhalfcycleofA.Cinput
voltage.
Duringthenegativehalfcycle,thediodeisreversebiasedanditdoesnotconduct.Sothereisnocurrent
floworvoltagedropacrossloadresistor.Thenetresultisthatonlythepositivehalfcycleoftheinput
voltageappearsattheoutput.
9.5.PROCEDURE:
1. Connectthecircuitasperthecircuitdiagram.
2. Applya.cinputusingtransformer.
3. Measuretheamplitudeandtimeperiodfortheinputandoutputwaveforms.
4. Calculateripplefactor.
MODELGRAPH:
FIG.13.5
-
8/11/2019 Electronis Circuits Lab 1
40/45
CIRCUITS AND DEVICES LAB MANUAL
SRINIVASAN ENGINEERING COLLEGE, PERAMBALURI YEAR
ISSUE: 01 REVISION: 00 40
TAB.9.1:
HALFWAVERECTIFIER:
Withoutfilter Withfilter
Inputsignal Outputsignal
Amplitude(V) Timeperiod Amplitude(V) Timeperiod
9.6.RESULT:
Thusthehalfwaverectifierwasconstructedandits
inputandoutputwaveformsaredrawn.Theripplefactorofcapacitivefilter
iscalculatedas
Ripplefactor=
-
8/11/2019 Electronis Circuits Lab 1
41/45
CIRCUITS AND DEVICES LAB MANUAL
SRINIVASAN ENGINEERING COLLEGE, PERAMBALURI YEAR
ISSUE: 01 REVISION: 00 41
10.FULLWAVERECTIFIER
10.1.AIM:
Toconstructa fullwaverectifierand tomeasuredcvoltageunder loadandtocalculate the
ripplefactor.
10.2.APPARATUSREQUIRED:
S.No. Name Range Quantity1. Transformer 230 V / 6-0-(-6) 12. Diode IN4007 23. Resistor 1 k 14. Capacitor 100F 15. CRO 30 MHz 16. Bread Board 1
FULLWAVERECTIFIERWITHOUTFILTER
-
8/11/2019 Electronis Circuits Lab 1
42/45
CIRCUITS AND DEVICES LAB MANUAL
SRINIVASAN ENGINEERING COLLEGE, PERAMBALURI YEAR
ISSUE: 01 REVISION: 00 42
FIG.8.1
FULLWAVERECTIFIERWITHFILTER
FIG.8.2
-
8/11/2019 Electronis Circuits Lab 1
43/45
CIRCUITS AND DEVICES LAB MANUAL
SRINIVASAN ENGINEERING COLLEGE, PERAMBALURI YEAR
ISSUE: 01 REVISION: 00 43
10.3.FORMULA
RippleFactor=[(Im/2)/(2*Im/)]2
-1
WhereImisthepeakcurrent
10.4.THEORY:
The fullwave rectifierconducts forboththepositiveandnegativehalfcyclesof the inputac
supply. Inordertorectifyboththehalfcyclesoftheacinput,twodiodesareused inthiscircuit.The
diodesfeedacommonloadRLwiththehelpofacentretappedtransformer.Theacvoltageisapplied
through a suitable power transformer with proper turns ratio. The rectifiers dc output is obtainedacrosstheload.
Thedcloadcurrentforthefullwaverectifieristwicethatofthehalfwaverectifier.Thelowest
ripplefactoristwicethatofthefullwaverectifier.Theefficiencyoffullwaverectificationistwicethatof
halfwaverectification.Theripplefactoralsoforthefullwaverectifierislesscomparedtothehalfwave
rectifier.
PROCEDURE:
1. Connectionsaregivenasperthecircuitdiagramwiyhoutfilter.
2. Note theamplitudeand timeperiodof the inputsignalat thesecondarywindingof the
transformerandrectifiedoutput.
3. RepeatthesamestepswiththefilterandmeasureVdc.4. Calculatetheripplefactor.
5. Drawthegraphforvoltageversustime.
MODELGRAPH
-
8/11/2019 Electronis Circuits Lab 1
44/45
CIRCUITS AND DEVICES LAB MANUAL
SRINIVASAN ENGINEERING COLLEGE, PERAMBALURI YEAR
ISSUE: 01 REVISION: 00 44
RESULT:Thus,thefullwaverectifierwasconstructedandtheripplefactorwascalculatedas
Ripplefactor =
10.5REVIEWQUESTIONS:
1. Whatismeantbyrectifier?
2. WritetheoperationoftwodiodesduringtheapplicationofACinputsignal
3. Whichtypeoftransformerusedfortherectifierinput?
-
8/11/2019 Electronis Circuits Lab 1
45/45
CIRCUITS AND DEVICES LAB MANUAL
SRINIVASAN ENGINEERING COLLEGE, PERAMBALURI YEAR
4. Defineripplefactor.
5. Writetheefficiencyofthisrectifier.