DMI COLLEGE OF ENGINEERINGdmice.ac.in/wp-content/uploads/2017/05/EC6211.pdf · 2018-12-24 · EC6211-Circuits and devices Lab Dept of Electronics & Communication Engg DMI college

DMI COLLEGE OF ENGINEERING

PALANCHUR CHENNAI – 600 123

DEPARTMENT OF ELECTRONICS AND COMMUNICATION

ENGINEERING

LABORATORY MANUAL

SUB CODE : EC 6211

SUBJECT TITLE : CIRCUITS AND DEVICES LABORATORY

SEMESTER : II

YEAR : I

DEPARTMENT : ELECTRONICS AND COMMUNICATION ENGINEERING

EC6211-Circuits and devices Lab Dept of Electronics & Communication Engg

DMI college of engineering 2

Vision of the Department

To develop committed and competent technologists in electronics and communication

engineering to be on par with global standards coupled with cultivating the innovations and

ethical values.

Mission of the Department:

DM 1: To be a centre of excellence in teaching learning process promoting active learning

with critical thinking.

DM 2: To strengthen the student’s core domain and to sustain collaborative industry

interaction with internship and incorporating entrepreneur skills.

DM 3: To prepare the students for higher education and research oriented activities imbibed

with ethical values for addressing the social need.

PROGRAM EDUCATIONAL OBJECTIVES (PEOs):

PEO1. CORE COMPETENCY WITH EMPLOYABILITY SKILLS: Building on

fundamental knowledge, to analyze, design and implement electronic circuits and systems in

Electronics and Communication Engineering by applying knowledge of mathematics and

science or in closely related fields with employability skills.

PEO2. PROMOTE HIGHER EDUCATION AND RESEARCH AND

DEVELOPMENT: To develop the ability to demonstrate technical competence and

innovation that initiates interest for higher studies and research.

PEO3. INCULCATING ENTREPRENEUR SKILLS: To motivate the students to become

Entrepreneurs in multidisciplinary domain by adapting to the latest trends in technology

catering the social needs.

PEO4. ETHICAL PROFESSIONALISM: To develop the graduates to attain professional

excellence with ethical attitude, communication skills, team work and develop solutions to the

problems and exercise their capabilities.



PROGRAM OUTCOMES (POs)

The Program Outcomes (POs) are described as.

1. Engineering Knowledge: Apply the knowledge of mathematics, science, engineering

fundamentals and an engineering specialization to the solution of complex engineering

problems.

2. Problem Analysis: Identify, formulate, review research literature, and analyze complex

engineering problems reaching substantiated conclusions using first principles of

mathematics, natural sciences, and engineering sciences.

3. Design / Development of solutions: Design solutions for complex engineering problems

and design system components or processes that meet the specified needs with appropriate

consideration for the public health and safety, and the cultural, societal, and environmental

considerations.

4. Conduct investigations of complex problems: Use research-based knowledge and

research methods including design of experiments, analysis and interpretation of data, and

synthesis of the information to provide valid conclusions.

5. Modern tool usage: Create, select, and apply appropriate techniques, resources, and

modern engineering and IT tools including prediction and modeling to complex engineering

activities with an understanding of the limitations.

6. The engineer and society: Apply reasoning informed by the contextual knowledge to

assess societal, health, safety, legal and cultural issues and the consequent responsibilities

relevant to the professional engineering practice.

7. Environment and sustainability: Understand the impact of the professional engineering

solutions in societal and environmental contexts, and demonstrate the knowledge of, and

need for sustainable development.

8. Ethics: Apply ethical principles and commit to professional ethics and responsibilities

and norms of the engineering practice.

9. Individual and team work: Function effectively as an individual and as a member or

leader in diverse teams, and in multidisciplinary settings.

10. Communication: Communicate effectively on complex engineering activities with the

engineering community and with society at large, such as, being able to comprehend and

write effective reports and design documentation, make effective presentations, and give and

receive clear instructions.



11. Project management and finance: Demonstrate knowledge and understanding of the

engineering management principles and apply these to one’s own work, as a member and

leader in a team, to manage projects and in multidisciplinary environments.

12. Life-long learning: Recognize the need for and have the preparation and ability to

engage in independent and lifelong learning in the broadest context of technological change.

PROGRAM SPECIFIC OUTCOMES (PSOs):

PSO1. Analyze and design the analog and digital circuits or systems for a given specification

and function.

PSO2. Implement functional blocks of hardware-software co-designs for signal processing

and communication applications.

PSO3. Design, develop and test electronic and embedded systems for applications with real

time constraint and to develop managerial skills with ethical behavior to work in a sustainable

environment.



INSTRUCTIONS TO STUDENTS FOR WRITING THE RECORD

In the record, the index page should be filled properly by writing the corresponding

experiment number, experiment name, date on which it was done and the page number.

On the right side page of the record following has to be written:

1. Title: The title of the experiment should be written in the page in capital letters. In the

left top margin, experiment number and date should be written.

2. Aim: The purpose of the experiment should be written clearly.

3. Apparatus/Tools/Equipments/Components used: A list of the Apparatus/Tools/

Equipments/ Components used for doing the experiment should be entered.

4. Theory: Simple working of the circuit/experimental set up/algorithm should be

written.

5. Procedure: Steps for doing the experiment and recording the readings should be

briefly described(flow chart/ Circuit Diagrams / programs in the case of

computer/processor related experiments)

6. Results: The results of the experiment must be summarized in writing and should be

fulfilling the aim.

On the Left side page of the record following has to be recorded:

a) Circuit/Program: Neatly drawn circuit diagrams for the experimental set up.

b) Design: The design of the circuit components for the experimental set up for selecting

the components should be clearly shown if necessary.

Observations:

i. Data should be clearly recorded using Tabular Columns.

ii. Unit of the observed data should be clearly mentioned

iii. Relevant calculations should be shown. If repetitive calculations are needed, only show

a sample calculation and summarize the others in a table.



SYLLABUS

EC 6211 CIRCUITS AND DEVICES LABAROTORY L T P C

0 0 3 2

1. Characteristics of PN Junction Diode

2. Zener diode Characteristics & Regulator using Zener diode

3. Common Emitter input - output Characteristics

4. Common Base input - output Characteristics

5. FET Characteristics

6. SCR Characteristics

7. Clipper and Clamper & FWR

8. Verifications Of Thevinin & Norton theorem

9. Verifications Of KVL & KCL

10. Verifications Of Super Position Theorem

11. Verifications of maximum power transfer & reciprocity theorem

12. Determination Of Resonance Frequency of Series & Parallel RLC Circuits

13. Transient analysis of RL and RC circuits

TOTAL: 45 PERIODS



COURESE OUTCOMES

CO1 Understand characteristics of PN junction diode and Zener diode

CO2 Understand characteristics of BJT

CO3 Understand characteristics FET

CO4 Design RL RC circuits

CO5 Verify basic circuit theorems

CO PO, PSO Mappings

Course

Code and

Course

name

CO

Program Outcomes PSO

1 2 3 4 5 6 7 8 9 10 11 12 1 2 3

EC6211

Circuits

and

Devices

Laboratory

CO 1 2 3 3 - 3 2 3 - 3 - - 2 3 2 -

CO 2 3 3 3 - 1 2 - - 1 - - 2 2 3 -

CO 3 1 3 3 2 3 2 - - 3 - 3 2 2 2 -

CO 4 3 3 3 2 3 1 3 - 3 - - 2 3 3 -

CO 5 3 3 3 2 3 1 3 - 3 - - 2 2 3 -

Average 2.4 3 3 2 2.6 1.6 3 - 2.6 - 3 2 3 3 -



SNO Content Beyond Syllabus Page No

14 Bridge Rectifier with and without filter 84

S.No. List of Experiments Page No

1 Introduction of Electronic Components 10

2 Verification of kirchoff’s voltage law and Kirchoff’s current

law 19

3 Verification of thevenin’s & norton’s theorem 23

4 Verification of superposition theorem 29

5 Verification of maximum power transfer theorem and

reciprocity theorem 34

6 Frequency response of series and parallel resonance circuit 38

7 Characteristics of PN junction diode and zener diode 44

8 Characteristics of BJT (CE configuration) 51

9 Characteristics of BJT (CB configuration) 57

10 Characteristics of UJT & SCR 63

11 Characteristics of JFET and MOSFET 68

12 Characteristics of TRIAC 75

13 Characteristics of photo diode and photo transistor 79



EXPT NO:01 Introduction of Electronic Components

1. Passive components

1.1 Resistor

Resistance Tolerance

Symbol A B C D F G J K M

Resistance

tolerance

+/-

0.05 0.1% 0.25 0.5 1 2 5 10 20

Token resistor color coding system applies to carbon film, metal oxide film, fusible,

precision metal film, and wirewound (cylindrical with enlarged ends) of the axial lead type.

This system is employed for resistors when the surface area is not sufficient to print the

resistance value for the past time. At present, Token resistor color coding system is applying



for automatization. The first three bands closest to one end of the resistor are used to

determine the resistance. The fourth band represents the tolerance of the resistor. Additional

information can be obtained from the first band. Generally, If an additional fifth band is black,

the resistor is wirewound resistor. If an additional fifth band is white, the resistor is fusible

resistor. If only one black band in the center, the resistor is called zero ohm resistor. The

colors of the first two bands represent the numerical value of the resistor. The third band

represents the power-of-10 multiplier.

1.2 Capacitors

Function

Capacitors store electric charge. They are used with resistors in timing circuits because it

takes time for a capacitor to fill with charge. They are used to smooth varying DC supplies by

acting as a reservoir of charge. They are also used in filter circuits because capacitors easily

pass AC (changing) signals but they block DC (constant) signals.

Capacitance

This is a measure of a capacitor's ability to store charge. A large capacitance means that more

charge can be stored. Capacitance is measured in farads, symbol F. However 1F is very large,

so prefixes are used to show the smaller values.

Three prefixes (multipliers) are used, µ (micro), n (nano) and p (pico):

µ means 10-6 (millionth), so 1000000µF = 1F

n means 10-9 (thousand-millionth), so 1000nF = 1µF

p means 10-12 (million-millionth), so 1000pF = 1nF

Capacitor values can be very difficult to find because there are many types of capacitor with

different labelling systems! There are many types of capacitor but they can be split into two

groups, polarised and unpolarised. Each group has its own circuit symbol.

Polarised capacitors (large values, 1µF +)

Examples: Circuit symbol:

Electrolytic Capacitors

Electrolytic capacitors are polarised and they must be connected the correct way

round, at least one of their leads will be marked + or -. They are not damaged by heat when

soldering. There are two designs of electrolytic capacitors; axial where the leads are attached

to each end (220µF in picture) and radial where both leads are at the same end (10µF in

http://www.kpsec.freeuk.com/555timer.htm

http://www.kpsec.freeuk.com/powersup.htm#smoothing

http://www.kpsec.freeuk.com/components/capac.htm#polarised

http://www.kpsec.freeuk.com/components/capac.htm#unpolarised



picture). Radial capacitors tend to be a little smaller and they stand upright on the circuit

board.

It is easy to find the value of electrolytic capacitors because they are clearly printed

with their capacitance and voltage rating. The voltage rating can be quite low (6V for

example) and it should always be checked when selecting an electrolytic capacitor. If the

project parts list does not specify a voltage, choose a capacitor with a rating which is greater

than the project's power supply voltage. 25V is a sensible minimum for most battery circuits.

Tantalum Bead Capacitors

Tantalum bead capacitors are polarised and have low voltage ratings like electrolytic

capacitors. They are expensive but very small, so they are used where a large capacitance is

needed in a small size.

Modern tantalum bead capacitors are printed with their capacitance, voltage and

polarity in full. However older ones use a colour-code system which has two stripes (for the

two digits) and a spot of colour for the number of zeros to give the value in µF. The standard

colour code is used, but for the spot, grey is used to mean × 0.01 and white means × 0.1 so

that values of less than 10µF can be shown. A third colour stripe near the leads shows the

voltage (yellow 6.3V, black 10V, green 16V, blue 20V, grey 25V, white 30V, pink 35V). The

positive (+) lead is to the right when the spot is facing you: 'when the spot is in sight, the

positive is to the right'.

For example: blue, grey, black spot means 68µF

For example: blue, grey, white spot means 6.8µF

For example: blue, grey, grey spot means 0.68µF

Unpolarised capacitors (small values, up to 1µF)

Examples: Circuit symbol:

Small value capacitors are unpolarised and may be connected either way round. They are not

damaged by heat when soldering, except for one unusual type (polystyrene). They have high

voltage ratings of at least 50V, usually 250V or so. It can be difficult to find the values of

these small capacitors because there are many types of them and several different labelling

systems!

Many small value capacitors have their value printed but without a multiplier,

so you need to use experience to work out what the multiplier should be!

For example 0.1 means 0.1µF = 100nF. Sometimes the multiplier is used in

place of the decimal point:

For example: 4n7 means 4.7nF.

http://www.kpsec.freeuk.com/components/capac.htm#colours



Capacitor Number Code

A number code is often used on small capacitors where printing is difficult:

the 1st number is the 1st digit,

the 2nd number is the 2nd digit,

the 3rd number is the number of zeros to give the capacitance in pF.

Ignore any letters - they just indicate tolerance and voltage rating.

For example: 102 means 1000pF = 1nF (not 102pF!)

Polystyrene Capacitors

This type is rarely used now. Their value (in pF) is normally printed

without units. Polystyrene capacitors can be damaged by heat when

soldering (it melts the polystyrene!) so you should use a heat sink (such as a crocodile clip).

Clip the heat sink to the lead between the capacitor and the joint.

Uses of Capacitors

Capacitors are used for several purposes:

Timing - for example with a 555 timer IC controlling the charging and discharging.

Smoothing - for example in a power supply.

Coupling - for example between stages of an audio system and to connect a

loudspeaker.

Filtering - for example in the tone control of an audio system.

Tuning - for example in a radio system.

Storing energy - for example in a camera flash circuit.

1.3 Inductors

It is component store energy in magnetic field. Ex : Coils, Decade Inductance box.

It is used in tuning circuits of radio receiver.

2.Active components

Diodes:As with transistors, diodes are fabricated from semi-conducting material. So, the

first letter in their identification is A for germanium diode or B for silicon diode. They can be

encased in glass, metal or a plastic housing. They have two leads: cathode (k) and an anode

(A). The most important property of all diodes is their resistance is very low in one direction

and very large in the opposite direction. When a diode is measured with a multimeter and it

reads a low value of ohms, this is not really the resistance of the diode. It represents the

voltage drop across the junction of the diode. This means a multimeter can only be used to

detect if the junction is not damaged. If the reading is low in one direction and very high in

the other direction, the diode is operational.When a diode is placed in a circuit and the voltage

on the anode is higher than the cathode, it acts like a low value resistor and current will flow.

If it is connected in the opposite direction it acts like a large value resistor and current does

http://www.kpsec.freeuk.com/555timer.htm

http://www.kpsec.freeuk.com/capacit.htm#charging

http://www.kpsec.freeuk.com/capacit.htm#discharging

http://www.kpsec.freeuk.com/powersup.htm#smoothing

http://www.kpsec.freeuk.com/capacit.htm#coupling

http://www.kpsec.freeuk.com/bdiags.htm#audio

http://www.kpsec.freeuk.com/components/other.htm#loudspeaker

http://www.kpsec.freeuk.com/bdiags.htm#audio

http://www.kpsec.freeuk.com/bdiags.htm#radio



not flow. In the first case the diode is said to be "forward biased" and in the second case it is

"reverse biased."

Symbol:

European diodes are marked using two or three letters and a number. The first letter is

used to identify the material used in manufacturing the component (A - germanium, B -

silicon), or, in case of letter Z, a Zener diode. The Second and third specifies the type and

usage of the diode. Some of the varities are: A – Low Power Diode, like the AA111, AA113,

AA121, etc. - they are used in the detector of a radio receiver; BA124, BA125 : varicap

diodes used instead of variable capacitors in receiving devices, oscillators, etc., BAY80,

BAY93, etc. - switching diodes used in devices using logic circuits. BA157, BA158, etc. -

these are switching diodes with short recovery time. B - two capacitive (varicap) diodes in the

same housing, like BB104, BB105, etc. Y - regulation diodes, like BY240, BY243, BY244,

etc. these regulation diodes come in a plastic packaging and operate on a maximum current of

0.8A. If there is another Y, the diode is intended for higher current. For example, BYY44 is a

diode whose absolute maximum current rating is 1A. When Y is the second letter in a Zener

diode mark (ZY10, ZY30, etc.) it means it is intended for higher current. G, G, PD - different

tolerance marks for Zener diodes. Some of these are ZF12 (5% tolerance), ZG18 (10%

tolerance), ZPD9.1 (5% tolerance). The third letter is used to specify a property (high current,

for example). American markings begin with 1N followed by a number, 1N4001, for example

(regulating diode), 1N4449 (switching diode), etc. Japanese style is similar to American, the

main difference is that instead of N there is S, 1S241 being one of them.

2.2 Zener diodes

Example: Circuit symbol:

a = anode, k = cathode

Zener diodes are used to maintain a fixed voltage. They

are designed to 'breakdown' in a reliable and non-destructive

way so that they can be used in reverse to maintain a fixed

voltage across their terminals. The diagram shows how they are connected, with a resistor in

series to limit the current.

Zener diodes can be distinguished from ordinary diodes by their code and breakdown

voltage which are printed on them. Zener diode codes begin BZX... or BZY... Their

breakdown voltage is printed with V in place of a decimal point, so 4V7 means 4.7V for

example. Zener diodes are rated by their breakdown voltage and maximum power:

The minimum voltage available is 2.4V.



Power ratings of 400mW and 1.3W are common

2.3 Transistors

Transistors are active components and are found everywhere in electronic circuits.

They are used as amplifiers and switching devices. As amplifiers, they are used in high and

low frequency stages, oscillators, modulators, detectors and in any circuit needing to perform

a function. In digital circuits they are used as switches.

Transistors amplify current, for example they can be used to amplify

the small output current from a logic IC so that it can operate a lamp, relay or

other high current device. In many circuits a resistor is used to convert the

changing current to a changing voltage, so the transistor is being used to

amplify voltage. A transistor may be used as a switch (either fully on with

maximum current, or fully off with no current) and as an amplifier (always partly on). The

amount of current amplification is called the current gain, symbol hFE.

Types of transistor

There are two types of standard transistors, NPN and PNP,

with different circuit symbols. The letters refer to the layers of

semiconductor material used to make the transistor. Most

transistors used today are NPN because this is the easiest type to

make from silicon. If you are new to electronics it is best to start

by learning how to use NPN transistors. The leads are labelled

base (B), collector (C) and emitter (E). In addition to standard

(bipolar junction) transistors, there are field-effect transistors

which are usually referred to as FETs.

Connecting

Transistors have three leads which

must be connected the correct way round.

Please take care with this because a wrongly

connected transistor may be damaged

instantly when you switch on. If you are

lucky the orientation of the transistor will be

clear from the PCB or stripboard layout

diagram, otherwise you will need to refer to a

supplier's catalogue to identify the leads.

The drawings on the right show the leads for

some of the most common case styles.

Transistor codes

There are three main series of transistor codes

used in the UK:

Codes beginning with B (or A), for example BC108, BC478 The first letter B is for silicon, A is for germanium (rarely used now). The second letter

Transistor circuit symbols

Transistor leads for some common case styles.



indicates the type; for example C means low power audio frequency; D means high power

audio frequency; F means low power high frequency. The rest of the code identifies the

particular transistor. There is no obvious logic to the numbering system. Sometimes a

letter is added to the end (eg BC108C) to identify a special version of the main type, for

example a higher current gain or a different case style. If a project specifies a higher gain

version (BC108C) it must be used, but if the general code is given (BC108) any transistor

with that code is suitable.

Codes beginning with TIP, for example TIP31A

TIP refers to the manufacturer: Texas Instruments Power transistor. The letter at the end

identifies versions with different voltage ratings.

Codes beginning with 2N, for example 2N3053 The initial '2N' identifies the part as a transistor and the rest of the code identifies the

particular transistor. There is no obvious logic to the numbering system.

Choosing a transistor

Most projects will specify a particular transistor, but if necessary you can usually

substitute an equivalent transistor from the wide range available. The most important

properties to look for are the maximum collector current IC and the current gain hFE. To make

selection easier most suppliers group their transistors in categories determined either by their

typical use or maximum power rating.

To make a final choice you will need to consult the tables of technical data which are

normally provided in catalogues. They contain a great deal of useful information but they can

be difficult to understand if you are not familiar with the abbreviations used. The table below

shows the most important technical data for some popular transistors, tables in catalogues and

reference books will usually show additional information but this is unlikely to be useful

unless you are experienced. The quantities shown in the table are explained below.

NPN transistors

Code Structure Case

style IC

max. VCE

max. hFE

min. Ptot

max. Category

(typical use) Possible

substitutes

BC107 NPN TO18 100mA 45V 110 300mW Audio, low power BC182 BC547

BC108 NPN TO18 100mA 20V 110 300mW General purpose, low power BC108C BC183

BC548

BC108C NPN TO18 100mA 20V 420 600mW General purpose, low power

BC109 NPN TO18 200mA 20V 200 300mW Audio (low noise), low

power BC184 BC549

BC182 NPN TO92C 100mA 50V 100 350mW General purpose, low power BC107 BC182L

BC182L NPN TO92A 100mA 50V 100 350mW General purpose, low power BC107 BC182

BC547B NPN TO92C 100mA 45V 200 500mW Audio, low power BC107B

BC548B NPN TO92C 100mA 30V 220 500mW General purpose, low power BC108B

BC549B NPN TO92C 100mA 30V 240 625mW Audio (low noise), low

power BC109

2N3053 NPN TO39 700mA 40V 50 500mW General purpose, low power BFY51

BFY51 NPN TO39 1A 30V 40 800mW General purpose, medium

power BC639

BC639 NPN TO92A 1A 80V 40 800mW General purpose, medium BFY51

http://www.kpsec.freeuk.com/components/tran.htm#key



power

TIP29A NPN TO220 1A 60V 40 30W General purpose, high

power


power TIP31C TIP41A

TIP31C NPN TO220 3A 100V 10 40W General purpose, high

power TIP31A TIP41A


power

2N3055 NPN TO3 15A 60V 20 117W General purpose, high

power

PNP transistors

Code Structure Case

style

IC

max.

VCE

max.

hFE

min.

Ptot

max.

Category

(typical use)

Possible

substitutes

BC177 PNP TO18 100mA 45V 125 300mW Audio, low power BC477

BC178 PNP TO18 200mA 25V 120 600mW General purpose, low power BC478

BC179 PNP TO18 200mA 20V 180 600mW Audio (low noise), low

power

BC477 PNP TO18 150mA 80V 125 360mW Audio, low power BC177

BC478 PNP TO18 150mA 40V 125 360mW General purpose, low power BC178

TIP32A PNP TO220 3A 60V 25 40W General purpose, high

power TIP32C

TIP32C PNP TO220 3A 100V 10 40W General purpose, high

power TIP32A

Photo diodes are similar to other, ordinary, diodes internally. One main difference is in that

that photo diode has an exposed surface to for light to fall onto. These diodes are acting as

high value resistor while in dark. It's resistance lowers as light gains in intensity. In their

behavior they are similar to photo resistors, apart from that as with all diodes polarity of the

component must be appropriately positioned.

Emitting diodes are special kind of photo-diodes. One of them is the LED, and some of

them include infra-red or ultra-violet emitting for different wireless communication purposes.

Most common area of application of IR-LEDs (Infra Red) are remote controllers for TVs and

other devices. Photo diodes are usually housed in round metallic or square plastic cases with a

glass window or a lens which focuses the incoming light. Photo-transistor's internal parts are

similar to internals of a regular transistor. One main difference between them is the glass

window which allows light to reach the crystal plate which holds all transistor's parts. With

changes of light intensity, resistance between base and the collector varies, and this influences

variations of the collector current. In this component light has the same role as voltage over

base of the regular transistor. When intensity rises, current through the transistor rises as well,

and other way round, if intensity fades, current fades.



Light Emitting Diode:(LED)

Example: Circuit symbol:

Function

LEDs emit light when an electric current passes through them.

List of components used in our Lab and its Specification

s.no Name of the

component

used in our lab

Symbol Terminal Identification Number

used in our

lab

1. PN Junction

Diode

IN4001

2. Zener Diode

Z9.1

3. BJT

BC107,

BC108

4. UJT 2N2646

5. SCR C106

6. JFET

BFW10,

BFW11

7. MOSFET

IRFZ44N

8. Photodiode

9. Photo

Transistor

10. TRIAC BT136

11. DIAC DB3



EXPT NO:02

VERIFICATION OF KIRCHOFF’S VOLTAGE LAW AND

KIRCHOFF’S CURRENT LAW

Aim:

(a) To Verify the Kirchoff’s Voltage law. (b) To Verify the Kirchoff’s Current law.

Statement:

Kirchoff’s Voltage Law:

In any closed circuit, the algebraic sum of all the electromotive forces and the potential

drops is equal to zero.

Kirchoff’s Current Law:

The algebraic sum all the currents at any junction in an electric circuit is zero. In other

words, the sum of the currents flowing towards a junction is equal to the sum of the currents

flowing away from it.

Apparatus and Components Required:

S.No Name of the Apparatus Range/Type Quantity

1

2

3

4

5

Regulated Power Supply

Ammeter

Connecting Wires

Resistors

Breadboard

0-30V

0-50mA

0-30mA

2.2K

1.5K, 3.9K

1

1

2

Few

4

1



Verification of KVL:

Tabulation:

S.No

Vin

V1

(Volts)

V2

(Volts)

Vin= V1 + V2

(Volts)

V3

(Volts)

V4

(Volts)

V2=V3+V4

(Volts)



Verification of KCL:

Tabulation:

S.No Input

Voltage

I(In Amps) I1

(In Amps)

I2

(In Amps)

I= I1 + I2

(In Amps)



Procedure:

Kirchoff’s Voltage law

1. Connections are made as per the circuit diagram.

2. Switch on the power supply.

3. Vary the R.P.S to a specified voltage and note down the corresponding voltmeter

readings.

4. Repeat the step 3 for various R.P.S voltage and tabulate the readings.

5. Switch off the power supply and remove the connections.

Kirchoff’s current law

1. Connections are made as per the circuit diagram.

2. Switch on the power supply.

3. Vary the R.P.S to a specified voltage and note down the corresponding ammeter

readings.

4. Repeat the step 3 for various R.P.S voltage and tabulate the readings.

5. Switch off the power supply and remove the connections.

Result:

Thus the Kirchoff’s Voltage and law and Kirchoff’s Current Law are verified.



EXPT NO:03 VERIFICATION OF THEVENIN’S & NORTON’S THEOREM

Aim:

To verify the Thevenin’s theorem for the given electric circuit.

Statement:

Any linear active network with output terminals A,B can be replaced by a single

voltage source Vth in series with a single resistance Rth.



1

2

3

4

5

6

7


Ammeter

Voltmeter

Connecting Wires

Resistors

Breadboard

DRB(Decade Resistance

Box)

0-30V

0-10mA

0-30V

-

1.0K

1.5K

3.9K

-

-

1

1

1

Few

2

1

1

1

1



Proof of the Theorem:

To prove the theorem, we need to demonstrate that the current flowing through a load

resistor RL connected to the network between points A & B is same as the load current

calculated using Thevenin’s Model.

Procedure:

To find Vth :

Calculate the Voltage across the points A, B of the network.

Vth = VAB = V

----------- x R2

R1+R2

To Find Rth :

Replace the voltage source with its internal resistance and then calculate the resistance

looking back at the point A,B.

Rth = R1R2

+ R3

R1+R2



Calculate Load Current Using Thevenin’s Model:

To Find IL(T)

IL(T) = Vth

amps

Rth + RL

Verification of theorem:

To find IL(P) :

Connect a load resistor RL to the active network and measure the value of load current

IL(P).



Tabulation:

S.No

Observations

Theoretical

Practical

1.

Vth

2.

Rth -

3.

IL

NORTON’S THEOREM:

Statement:

Norton’s theorem states that, any linear network with output terminals A,B can be replaced by a single current source ISC in parallel with a single resistance Rth.

To Find Short Circuit Current (ISC):

To Find RN :



To Measure the Load Current IL :

Procedure:

1. For the given circuit, short circuiting the DC voltage source and open circuit the load

resistance RL across it find the equipment resistance Rth using multimeter.

2. For the given circuit, set the constant voltage on DC voltage source and replace the load

resistance RL by an ammeter and find Short circuit current Isc.

3. Constant voltage set in the DC voltage source, Connect Ammeter in series with load

resistance and fined the current flows through load resistance RL.

4. Verify these values with theoretical values.

Calculation: Applying mesh current analysis to find Isc

Δ = R1 + R2 -R2 =

-R2 R2 + R3

Δ1 = R1 + R2 V

-R2 0

Isc = Δ1 /Δ = ------------- amps

Rth = R1R2

--------- + R3 = ------------ ohms

R1+R2

IL = Isc.Rth

--------- = --------- amps

Rth + RL



Tabulation:

S.No

Observations

Theoretical

Practical

1.

ISC

2.

Rth

3.

IL

Result:

Thus the Thevenin’s and Norton’s theorem were verified for the given electric circuit.



EXPT NO:04 VERIFICATION OF SUPERPOSITION THEOREM

Aim:

To verify the Superposition theorem for the given electric circuits.

Statement:

The Superposition theorem states that the response in a circuit with multiple sources

are given by the algebraic sum responses due to the individual source acting alone.



1

2

3

4

5

6


Ammeter

Voltmeter

Connecting Wires

Resistors

Breadboard

0-30V

0-10mA

0-30V

-

1.5K

3.9K

-

1

1

1

Few

2

1

1

Procedure:

1. Connections are given as per the circuit diagram.

2. In practical response V1 the voltage is varied and the corresponding I1 is noted down.

3. In practical response V2 the voltage is varied and the corresponding I2 is noted down.

4. The total response V1 and V2 of equal value in steps and the total current is noted.

5. Summation of I1 and I2 is an equal to It (Total Current).



Circuit Diagram:

Circuit 1:

Circuit 2:

Circuit 3:



Calculation:

Circuit1:

Apply KVL to loop1:

15 = 1.5i1 + 3.9(i1+i2)

15 = 5.4i1 + 3.9i2 ----------- (1)

Apply KVL to loop2:

20 = 1.5i2 + 3.9(i1+i2)

20 = 5.4i2 + 3.9i1 ----------- (2)

Δ = 4.59.3

9.34.5

Δ1 = 4.520

9.315

Δ2 = 209.3

154.5

Where I1 = Δ1/ Δ =

I2 = Δ2/ Δ =

I = I1+I2 =

Circuit 2:

Apply KVL to loop1: Similarly apply KVL to loop 1 and loop 2 for the circuit 2 and find I1

Apply KVL to loop1:

15 = 1.5i1 + 3.9(i1+i2)

15 = 5.4i1 + 3.9i2 ----------- (1)

Apply KVL to loop2:

0 = 1.5i2 + 3.9(i1+i2)

0 = 5.4i2 + 3.9i1 ----------- (2)

Δ = 4.59.3

9.34.5



Δ1 = 4.50

9.315

Δ2 = 09.3

154.5

Where i1 = Δ1/ Δ =

i2 = Δ2/ Δ =

I1 = i1+i2 = Current flow due to the V1 source alone =

Circuit 3:

Apply KVL to loop1: Similarly apply KVL to loop 1 and loop 2 for the circuit 3 and find I2

Apply KVL to loop1:

0 = 1.5i1 + 3.9(i1+i2)

0 = 5.4i1 + 3.9i2 ----------- (1)

Apply KVL to loop2:

20 = 1.5i2 + 3.9(i1+i2)

20 = 5.4i2 + 3.9i1 ----------- (2)

Δ = 4.59.3

9.34.5

Δ1 = 4.520

9.30

Δ2 = 209.3

04.5

Where i1 = Δ1/ Δ =

i2 = Δ2/ Δ =

I2 = i1+i2 = Current flow due to the V2 source alone =



Tabulation:

S.No

Circuit

V1

V2

I1

I2

I1+ I2

1.

2.

3.

Circuit 1

Circuit 2

Circuit 3

15

15

0

20

0

20

Result:

Thus the Superposition theorem is verified for the given electric circuit.



EXPT NO:05 VERIFICATION OF MAXIMUM POWER TRANSFER

THEOREM AND RECIPROCITY THEOREM

Aim:

To verify the maximum power transfer theorem and reciprocity theorem for the given

electric circuits.

Statement:

Maximum Power transfer theorem

Its states that Maximum power is transferred to the load when the load resistance

equals the equivalent resistance of the circuits (Thevenin’s resistance) as seen from the load.

Statement:

Reciprocity theorem

This theorem states that if a voltage source V acting in one branch of a network causes

a current I to flow in another branch of the network, then the same voltage source V acting in

the second branch would cause an identical current I to flow in the first branch.

Apparatus and components required:

S.No Name of the

Apparatus

Range/Type Quantity

1

2

3

4

5

6

7


Ammeter

Voltmeter

Connecting Wires

Resistors

Breadboard

DRB(Decade

Resistance Box)

0-30V

0-10mA

0-30V

-

1.5K

3.9K

-

1

1

1

Few

2

1

1

1



Procedure:

Maximum Power transfer theorem


2. Keep the input voltage as constant, by varying the load resistance in steps, Note down

the corresponding current through the load IL.

3. Repeat step 2 till it reaches the maximum and also calibrates the dropping current.

4. Tabulate the reading and calculate the power delivered to the load RL.

5. Plot the graph between PL versus RL and find the value of RL which will be equal to Rth

for PL (max).

6. Also find the resistance ‘Rth‘ by using multimeter, removing the load resistance.

Reciprocity theorem


2. Keep the input voltage as constant, and find the corresponding current I from the

ammeter, it flow in another branch of the network.

3. Then interchange the voltage source (V) and Ammeter in the circuit, and keep the same

input voltage and find the current I from the ammeter it flow in the first branch.

4. Tabulate the reading. Both Currents are equal.

Tabulation:

S.No RL (KΩ) IL (mA) PL = IL2RL (mW)



Circuit Diagram:

Model Graph



RECIPROCITY THEOREM

Circuit Diagram:

Figure 1:

Figure 2:

Result:

Thus Power delivered to the load is found to be Maximum when RL = Rth. Hence the

maximum power transfer theorem is verified. The Reciprocity theorem also verified.



EXPT NO:06 FREQUENCY RESPONSE OF SERIES AND PARALLEL

RESONANCE CIRCUIT

Aim:

To study the frequency response and bandwidth of Series and Parallel resonance

circuit.

Apparatus and components required:


1

2

3

4

5

6

7

Multimeter

Connecting Wires

Breadboard

Decade Resistance Box

(DRB)

Decade Capacitance

Box(DCB)

Decade Inductance

Box(DIB)

Function Generator

-

-

-

-

-

(0-1Mhz)

1

Few

1

1

1

1

1

Theory:

RESONANCE:

Resonance is very important phenomenon is in communication to select particular

frequency and reject all other frequencies. Resonance is defined as in which applied voltage

and resulting current are In phase. In other words, an AC circuit is set to be in resonance if it

exhibits unity power factor. At resonance inductive reactance is equal to the capacitive

reactance. Resonance occurs on series RLC circuits is referred to as “Series resonance”.

Resonance occurs on parallel RLC circuits is referred to as “Parallel resonance”. In RLC circuit resonances may be produced by either varying frequency for given

constant L & C or varying either L&C or both for a given frequency.

Q –factor = 2π maximum energy stored per cycle

------------------------------------------------

Energy dissipated per cycle

Bandwidth of a RLC resonance circuit is defined as the width of resonance curve upto

frequency at which the power in the circuit is half of its maximum value.

Bandwidth = f2 – f1 ; f2 = upper cut off frequency; f1 = lower cut off frequency

Selectivity of an resonant circuits is defined as the ability of the circuit to distinguish

between desired and undesired frequencies. Selectivity is also defined as the ratio of resonant

frequency to bandwidth. Selectivity = f0 / f2 – f1



Circuit Diagram:

Series Resonance Circuit:

Parallel Resonance Circuit:



Tabulation:

Series Resonant Circuit:

SL No Frequency (Hz) Practical Current (I) mA

Parallel Resonant Circuit:

SL No Frequency (Hz) Practical Current (I) mA



Calculations:

Series and Parallel Resonance Circuit:

R=

L=

C=

Resonant Frequency, fr = 1/2π√LC

Lower Cut off Frequency, f1 = fr – R/4 πL

Upper Cut off Frequency, f1 = fr + R/4 πL

Bandwidth:

Bandwidth = f2 – f1 (Practical)

Bandwidth = R/2 πL (Theoretical)

Q-Factor:

Q = (1/R) * √(L/C) (Theoretical)

Q = fr/ (f2 –f1) (Practical)



Model Graph:

Series Resonance Circuit:

Parallel Resonance Circuit:



Procedure:


2. The resonant frequency is calculated by keeping the value of ‘L’ constant and varying the value of capacitance ‘C’.

3. The resonant frequency is calculated by using the formula, fr = 1/2π√LC

4. For finding the frequency response the value of capacitance and inductance are kept as

constant.

5. The frequency value is increased and its corresponding I values are noted.

6. A graph is plotted between frequency and current taking f along X-axis and frequency

along Y-axis.

7. Thus the resonant frequency and frequency response of RLC Series and Parallel has

been found.

Result:

Thus the frequency response of the series and parallel circuit are plotted and its bandwidth

calculated.



EXPT NO:07 CHARACTERISTICS OF PN JUNCTION DIODE AND

ZENER DIODE

Aim

To study the characteristics of PN Junction diode and Zener diode under forward and

reverse bias condition.


S.No Name of the

Apparatus

Range/Type Qty

1 RPS(Regulated Power

Supply)

0-30v 1

2 Ammeter 0-30mA,0-500µA Each 1

3 Voltmeter 0-30V,0-2V Each 1

4 PN Junction Diode IN4007 1

5 Zener Diode Z9.1 1

6 Resistor 1 KΩ 1

7 Bread board - 1

8 Connecting Wires - As Required

Theory:

PN DIODE:

A semiconductor PN Junction diode is an electronic device that is fabricated by

sandwiching a P – type material with an N – type material. The diode is basically referred to

as rectifier diode, as it is used in converting an AC signal to DC signal. The material used

determines the cut in voltage of the diode, for germanium the cut in voltage is 0.3V and for

the silicon cut in voltage is 0.7V. The diode is a resistive element, which conducts only when

the input voltage is above the rated voltage, this voltage is referred to as Barrier voltage. The

diode conducts in both forward and reverse mode.

FORWARD MODE:

In this mode the resistance offered by the diode is small, as the diode is connected in

the forward direction P – type connected to the positive node in the supply and N – type

connected to the negative mode of the supply, Once the applied voltage exceeds the barrier

voltage the diode starts conducting which leads to saturation.



REVERSE MODE:

In this mode the resistance offered by the diode is large, as the diode is connected in

the reverse direction P – type connected to the negative node in the supply and N – type

connected to the positive node of the supply. Once the applied voltage exceeds the barrier

voltage the diode starts conducting which leads to breakdown.

ZENER DIODE:

A Semiconductor Zener diode is an electronic device that is fabricated by sandwiching

a P – type material with a N – type material. The diode is basically referred to as

reference/regulator diode as it used to regulate the DC signal. The diode works in the reverse

breakdown region in a different way that is based on the geometric of doping. The diode

conducts in both forward and reverse mode. The diode is primarily used in the reverse

direction only. The voltage at which the diode break is known as Zener breakdown.

Zener Breakdown:

Due to the applied reverse potential, an electric field exists near the junction, this field

exerts a strong electric on the co-volant bond and this breaks the band leading to zener

breakdown.

PROCEDURE

Forward Bias:


2. Vary the supply voltage in steps of 0.1v and voltage across the diode is measured by

voltmeter and current by ammeter.

3. The readings are tabulated.

4. Graph is plotted between forward Voltage (in X-axis) and Forward Current (in Y axis).

5. Forward dynamic and static resistance is measured from this graph.

Reverse Bias:


2. Vary the supply voltage in steps of 1v and voltage across the diode is measured by

voltmeter and current by ammeter.

3. The readings are tabulated.

4. Graph is plotted between forward Voltage (in X-axis) and Forward Current (in Y axis).

5. Reverse Saturation Current, Reverse dynamic and static resistance is measured from

this graph.



Circuit Diagram:

PN Junction Diode:

Forward Bias

Reverse Bias



Zener Diode:

Forward Bias

Reverse Bias.



Model Graph: Zener Diode

PN – Junction Diode



Tabular Column:

PN Junction Diode:

FORWARD BIAS REVERSE BIAS

VF (Volts) IF(mA) VR (Volts) IR(μA)

Zener diode:


VF (Volts) IF(mA) VR (Volts) IR(mA)

CALCULATIONS

PN Junction Diode:

Static Forward Resistance, Rs = V/I =

Static Reverse Resistance, rs = V/I =



Dynamic Forward Resistance, Rd = ∆VF/∆IF =

Dynamic Forward Resistance, rd = ∆VR/∆IR =

Zener Diode:

Static Forward Resistance, Rs = V/I =

Static Reverse Resistance, rs = V/I =

Dynamic Forward Resistance, Rd = ∆VF/∆IF =

Dynamic Forward Resistance, rd = ∆VR/∆IR =

RESULT

Thus the Forward and reverse characteristics of PN Junction Diode and Zener diode are

studied.



EXPT NO:08 CHARACTERISTICS OF BJT (CE CONFIGURATION)

Aim:

To Obtain the input and output Characteristics of Common Emitter configuration and

find its h-parameters.


S.No Name of the Apparatus Range/No/Type Quantity

1 Transistor BC107 1

2 Voltmeter 0-2V,0-30V Each1

3 Ammeter 0-500µA, 0-30mA, Each 1

4 DC Power Supply (Dual) 0-30V 1

5 Breadboard 1

6 Resistors 1k,10k, Each 1

7 Connecting Wires As required

H-parameters:

Input Resistance (with output short circuit)

hie = ΔVBE VBE2 - VBE1

-------------- at Constant VCE (ohms) = -------------------

ΔIB IB2 - IB1

Forward current transfer ratio (with output short circuited)

hfe = ΔIC IC2 - IC1

-------------- at Constant VCE ------------------

ΔIB IB2 - IB1



Reverse voltage transfer ratio (with input open circuit)

hre = ΔVBE VBE2 - VBE1

-------------- at Constant IB ---------------

ΔVCE VCE2 - VCE1

Output Admittance (with input short circuited)

hoe = ΔIC IC2 - IC1

-------------- at Constant IB (mhos) -----------------

ΔVCE VCE2 – VCE1

Theory:

The transistor is a semiconductor device having three terminals called Emitter, Base

and Collector. It consists of two diodes namely, emitter-base diode and collector-base diode

connected back to back, BJT is classified in to NPN and PNP transistor and doping varies

between the three layers.

In BJT(Bipolar Junction Transistor) current conduction takes place by both minority

and majority charge carriers. It also called current controlled device, because the output

current is controlled by its input current, The external DC biasing is applied to the transistor to

fix the Q – point in any one of the region out of three region ie.active, Cut-off and saturation

region, used for different applications. Always the emitter-base junction is forward biased and

collector to base is reverse biased and Q – point is fixed on center of DC load line(In active

region) to operate transistor as an amplifier.

There are three possible arrangements (configuration) for investigating its DC

Characteristics. From each of these configurations three sets of characteristics may be derived,

there are the input characteristics, Output characteristics and Current gain characteristics.



Circuit Diagram:

Model Graph:

Input Characteristics:



Output Characteristics:

Tabulation:


VCE (V) VCE (V)

VBE (V) IB (μA) VBE (V) IB (μA)




IB (μA) IB (μA) VCE (V) IC (mA) VCE (V) IC (mA)

h-parameters:

Parameters Practical Readings

hie

hfe

hre

hoe

Procedure:


1. Connect the circuit as per the circuit diagram.

2. Set VCE = 5V, vary, VBE insteps of 0.1V & note down the corresponding IB and repeat

the above procedure for 10V & so on.

3. Plot the graph : VBE vs IB for a constant VCE.

4. Find the h-parameters : hfe & hie.





2. Set IB = 20μA, vary VCE insteps of 1V & note down the corresponding IC . Repeat the

above procedure for 40μA,80μA & so on. 3. Plot the graph: VCE vs IC for a constant of IB .

4. Find the h-parameters: hoe & hre.

Result:

Thus the static characteristics of transistor in Common Emitter configuration studied.



EXPT NO:09 CHARACTERISTICS OF BJT (CB CONFIGURATION)

Aim:

To Obtain the input and output Characteristics of Common Base configuration and find

its h-parameters.



1 Transistor BC107 1


3 Ammeter 0-30mA,0-10mA, Each 1


5 Breadboard 1

6 Resistors 330Ω 2


h-parameters:

Input Resistance (with output short circuit)

hib = ΔVEB VEB2 - VEB1

-------------- at Constant VCB (ohms) ----------------

ΔIE IE2 - IE1

Forward current transfer ratio (with output short circuited)

hfb = ΔIC IC2- IC1

-------------- at Constant VCB ------------

ΔIE IE2 - IE1



Reverse voltage transfer ratio(with input open circuit)

hre = ΔVEB VEB2 - VBE1

-------------- at Constant IE ----------------

ΔVCB VCB2 - VCB1

Output Admittance (with input short circuited)

hoe = ΔIC IC2 - IC1

-------------- at Constant IE (mhos) -----------

ΔVCB VCB2 –VCB1

Theory:

The transistor is a semiconductor device having three terminals called Emitter, Base

and Collector. It consists of two diodes namely, emitter-base diode and collector-base diode

connected back to back, BJT is classified in to NPN and PNP transistor and doping varies

between the three layers.

In BJT (Bipolar Junction Transistor) current conduction takes place by both minority

and majority charge carriers. It also called current controlled device, because the output

current is controlled by its input current, The external DC biasing is applied to the transistor to

fix the Q – point in any one of the region out of three region ie.active, Cut-off and saturation

region, used for different applications. Always the emitter-base junction is forward biased and

collector to base is reverse biased and Q – point is fixed on center of DC load line(In active

region) to operate transistor as an amplifier.

There are three possible arrangements (configuration) for investigating its DC

Characteristics. From each of these configurations three sets of characteristics may be derived,

there are the input characteristics, Output characteristics and Current gain characteristics.



Circuit Diagram:

Model Graph:





Tabulation:


VCB (V) VCB (V)

VEB (V) IE (mA) VEB (V) IE (mA)




IE (mA) IE (mA)

VCB (V) IC (mA) VCB (V) IC (mA)

h-parameters:

Parameters Practical Readings

hib

hfb

hrb

hob



Procedure:



2. Set VCB = 5V, vary, VEB insteps of 0.1V & note down the corresponding IE and repeat

the above procedure for 10V & so on.

3. Plot the graph : VEB vs IE for a constant VCB.

4. Find the h-parameters : hfb & hib.



2. Set IE = 20mA, vary VCB insteps of 1V & note down the corresponding IC . Repeat the

above procedure for 40μA,80μA & so on. 3. Plot the graph: VCB vs IC for a constant of IE .

4. Find the h-parameters: hob & hrb.

Result:

Thus the static characteristics of transistor in Common base configuration studied.



EXPT NO:10 CHARACTERISTICS OF UJT & SCR

Aim:

To study the static Characteristics of UJT and SCR.



1 UJT(Uni Junction Transistor) 2N2646 1

2. SCR C106 1


4 Ammeter 0-500µA,0-30mA 1


6 Breadboard 1

7 Resistors 1K,100Ω,1K/1W,100K Each 1


Theory:

UJT:

UJT is three terminal (unit junction) semiconductor switching devices. Three terminals

are Emitter, Base1, Base2, emitter is always nearer to B2 than B1. UJT is called as double

base diode. UJT as unique characteristics that when it is triggered the emitter current

increases regenerative until it is limited by emitter power supply, now the UJT is in ON

condition. UJT acts as forward bias PN diode. There is no emitter power supply then UJT is in

OFF condition. UJT is acts as reverse bias PN diode. UJT can be used as oscillator, as saw-

tooth generator, for phase control, as limiting circuit, as multi-vibrator, for triggering devices

such as SCR. UJT exhibits negative resistance in between peak and valley points.

SCR:

SCR belongs to the power electronics (Thyristors) family, which can handle high

power, and it is primarily used in the control of motors, control of DC power, rectifiers and

used in inverters. SCR is operated with the gate, as the gate is the node, which determines the

angle of firing. Once SCR is fired (triggered) there is conduction and it works lie and ordinary

diode. Once the SCR is turned ON, the gate losses control and cannot be used to switch the

device OFF. One way to turn the device OFF is by lowering the anode current below the

holding current by reducing the supply voltage below the holding voltage, keeping the gate

open. At this point even if the gate signal is removed the device keeps ON conducting, till the

current level is maintain to a minimum level of holding current. If gate is not

initiated(triggered) then SCR will not conduct even though if we increasing the applied

voltage.



Circuit Diagram:

UJT

SCR



Model Graph:

UJT

SCR



Tabulation:

UJT

S.No

VB1B2 VB1B2

VEB IE VEB IE

SCR

Tabulation:

S.No

IG (μA) IG (μA)

VAK (V) IA (mA) VAK (V) IA (mA)

Procedure:

UJT


2. The Voltage VB1B2 is kept at a constant value.

3. By varying the supply voltage at the input side the corresponding voltage VEB1 and current

IE is noted.



4. Repeat the same procedure for various constant values of VB1B2.

5. Plot the graph between VBE and IE.

6. From the graph note down the Peak point VP and value voltage VD and calculate the

intrinsic stand off ratio.

Intrinsic Stand off Ratio(η) η = VP – VD

------------

VB1B2

Where VP = Peak Voltage

VD = Diode Voltage

For Si -> 0.7V

Ge-> 0.2V

VB1B2 -> Voltage Applied to the B1 & B2 terminals.

SCR

Procedure:


2. Vary the gate supply (VGS) voltage to keep IG = 100μA as constant. 3. Anode supply VAK is switched ON. Vary the Anode Supply Voltage VAK in steps and the

changes in the corresponding Ammeter (IA) readings are noted.

4. Step 3 is continued until break over voltage VBO is obtained.

5. VAK is further increased and the corresponding Voltmeter VAK and ammeter IA readings

are tabulated.

6. Step 5 is continued until anode ammeter shows full scale deflection.

7. The Supply voltage VAK is brought back to zero.

8. Adjusting the supply VAK to keep IG = 200μA. 9. Repeat the steps 3,4,5 & 6.

10. Plot the graph between VAK and IA.

Result:

Thus the static characteristics of UJT & SCR was obtained.

UJT: Intrinsic stand of ratio (η) =

SCR

1. Latching Current (IL) =

2. Holding Current (IH) =

3. Forward Break over Voltage (VBR) =



EXPT NO:11 CHARACTERISTICS OF JFET AND MOSFET

Aim:

To obtain the Drain and Transfer characteristics of JFET and MOSFET in common

source configuration and find its parameters values.



1 JFET(Junction Field

Effect Transistor)

BFW10 1

2. MOSFET IRFZ44N 1


4 Ammeter 0-10mA 1


6 Breadboard 1

7 Resistors 33KΩ,1KΩ Each 1


Theory:

Like a bipolar junction transistor, a field effect transistor is also a three terminal which

are source, drain and gate. FET is also called as uni-polar device because its function depends

only upon the one type of carrier ie. due to either majority or minority charge carriers. It is

also called voltage control device, because the output current is controlled by its input voltage.

A field effect transistor can be either a JFET of MOSFET. Again a JFET can either

have n-channel or p-channel. An n-channel has an n-type semiconductor bar. The two ends of

which the drain and source terminal on the two side of this bar, PN junction are made. This p-

region makes gates. Usually the two gates are connected together to form a single gate. The

gate is given a negative bias with respect to the source. The drain is given positive potential

with respect to the source, In case of p-channel JFET the terminal of all the batteries are

reversed.

In this case, PN junction is reverse bias and the thickness of the depletion region

increases. As VGS is decreased from zero, drain is positive with respect to the source with VGS

= 0. Now majority carriers flow through the n-channel from source to drain. Therefore the

conventional current flow from drain to source since the current is controlled by only majority

carriers, FET is called as uni-polar device.

The drain current ID is controlled by the electric field that extends into the channel due

to reverse bias voltage applied to the gate. The drain current depends on the drain voltage VDS

and the gate voltage VGS. Any of this variables may be fixed and the relation between the



other two are determined when VDS=VP, ID becomes maximum. When VDS is increased

beyond VP, the length of the pinch off region are saturation region increases.

MOSFET is an improved version of JFET. MOSFET can be made very small

compared to BJT’s and hence can be used to design VLSI circuits.

MOSFET differ from JFET in that has no PN junctions structure, instead the gate of

the MOSFET is insulated from the channel by Sio2 layer. Due to this input resistance of

MOSFET is greater than JFET. Therefore it is also called as insulated gate FET(IGFET).

MOSFET has two types depletion mode MOSFET, enhancement mode MOSFET. The

negative gate voltage depletes the channel of free electrons. Due to this reason we call this

mode as depletion mode.

The positive increases the number of free electrons moving through the channel, as the

gate increases the number of free electrons moving through the channel gets increased. This

enhances the conduction process of the channel. Due to this reason positive gate operation is

referred as enhancement mode.

Circuit Diagram:

JFET



MOSFET

Model Graph:

JFET

Drain Characteristics: Transfer Characteristics:



MOSFET

Drain Characteristics: Transfer Characteristics:

Tabulation:

Drain Characteristics:

JFET MOSFET

-VGS = (V) -VGS = (V) VGS = (V) VGS = (V)

VDS(V) ID(mA) VDS(V) ID(mA) VDS(V) ID(mA) VDS(V) ID(mA)



Transfer Characteristics:

JFET MOSFET

VDS = (V) VDS = (V) VDS = (V) VDS = (V)

-VGS(V) ID(mA) -VGS(V) ID (mA) VGS(V) ID (mA) VGS (V) ID(mA)

Calculations:

JFET Parameters:

1. DC Drain Resistance (RDS)

RDS = VDS / ID

2. AC Drain Resistance (rd)

rd = (ΔVDS /ΔID ) at constant VGS.

3. Transconductance (Gm)

Gm = (ΔID / ΔVGS ) at constant VDS

4. Amplification Factor (μ) μ = rd * Gm

MOSFET Parameters:

1. DC Drain Resistance (RDS)

RDS = VDS / ID

2. AC Drain Resistance (rd)



rd = (ΔVDS /ΔID ) at constant VGS.

3. Transconductance (Gm)

Gm = (ΔID / ΔVGS ) at constant VDS

4. Amplification Factor (μ) μ = rd * Gm

Procedure:

The connections are given as per the circuit diagram.

JFET

Drain characteristics:

1. VGS is kept constant by adjusting the input side power supply.

2. By varying the supply voltage at the output side the corresponding Voltage VDS and

Current ID is noted.

3. Repeat the same procedure for various constant values of VGS .

4. Plot the graph between ID and VGS .


1. Drain Voltage VD is kept constant by adjusting the output side power supply.

2. By Varying the supply at the input side the corresponding voltage VGS and current ID is

noted.

3. Repeat the same procedure for various constant values of VD.

4. Plot the Graph between VGS and ID.

MOSFET

Drain characteristics:

1. VGS is kept constant by adjusting the input side power supply.

2. By varying the supply voltage at the output side the corresponding Voltage VDS and

Current ID is noted.

3. Repeat the same procedure for various constant values of VGS .

4. Plot the graph between ID and VGS .


1. Drain Voltage VD is kept constant by adjusting the output side power supply.

2. By Varying the supply at the input side the corresponding voltage VGS and current ID is

noted.

3. Repeat the same procedure for various constant values of VD.



4. Plot the Graph between VGS and ID.

Result:

Thus the Drain and Transfer Characteristics of JFET & MOSFET has been studied and

its parameters are calculated.

JFET MOSFET

DC Drain Resistance =

AC Drain Resistance =

Transconductance =

Amplification Factor =

Pinch off Voltage =

IDSS =

DC Drain Resistance =

AC Drain Resistance =

Transconductance =

Amplification Factor =

Pinch off Voltage =



EXPT NO:12 CHARACTERISTICS OF TRIAC

Aim:

To study the characteristics of Triac.

Apparatus and components Required:


1 Triac BT136 1

2 Voltmeter 0-30V 1

3 Ammeter 0-50mA 2


5 Breadboard 1

6 Resistors 2.2K 2


Theory:

TRIAC belong to the power electronics (thyristors) family, which can handle high

power, and it is primarily used in the control of motors, control of AC power and used in

inverters. TRIAC behaves as two inverse – parallel connected SCR’s with a single gate terminal. SCR is a three terminal devices which are gate (G), Main Terminal 1(MT1) and

Main terminal (MT2). TRIAC is a bidirectional device because which can conduct in both

direction. If MT2 is positive with respect to MT1 then current flows from MT2 to MT1. If

MT1 is positive with respect to MT2 then current flows from MT1 to MT2.

TRIAC triggering conditions are

1. MT2 is positive and gate is positive.

2. MT2 is positive and gate is negative.

3. MT2 is negative and gate is positive.

4. MT2 is negative and gate is negative.



Circuit Diagram:

Forward Bias:

Reverse Bias:



Model Graph:

Procedure:

Forward Characteristics:


2. Apply the positive potential to gate terminal with respect to MT1 , vary the gate voltage

to keep gate current to IG = 2mA as constant.

3. Forward bias the Triac. Given supply VF in between the terminals MT1 and MT2, MT2 is

positive with respect to MT1

4. Vary the supply voltage VF in steps and the changes in the corresponding Ammeter (IF)

readings are noted.


6. VF is further increased and the corresponding (Voltmeter VF and Ammeter IF) readings

are tabulated.


8. Plot the graph between VF and IF .



Reverse Characteristics:


2. Apply the negative potential to gate terminal with respect to MT1 , vary the gate voltage

to keep gate current to IG = 2mA as constant.

3. Forward bias the Triac. Given supply VF in between the terminals MT1 and MT2, MT1 is

positive with respect to MT2

4. Vary the supply voltage VR in steps and the changes in the corresponding Ammeter (IR)

readings are noted.


6. VR is further increased and the corresponding (Voltmeter VR and Ammeter IR) readings

are tabulated.


8. Plot the graph between VR and IR .

Tabulation:


IG (mA) IG (mA)

VF (V) IF (mA) VR (V) IR (mA)

Result:

Thus the characteristics of Triac have been studied.



EXPT NO:13 CHARCTERISTICS OF PHOTO DIODE AND PHOTO

TRANSISTOR

Aim:

To determine the characteristics of Photodiode and Photo transistor.



1 Photo diode - 1

2 Photo Transistor - 1

2 Voltmeter 0-3V,0-30V Each 1

3 Ammeter 0-10mA,0-100µA, Each 1


5 Breadboard 1

6 Resistors 1K 1


Theory:

Both photo diode and photo transistor operates based on the principle of “Photo conductive effect”. When radiation is incident on a semi-conductor, it absorbs some light, as a

result its conductivity varies directly with the intensity of light and its resistance varies

inversely with the intensity of light. This effect is called as photo conductive effect.

PHOTO DIODE

It is a semi-conductor PN junction device whose region of operation is limited to the

reverse bias region. Photo diode is connected in reverse bias condition. The depletion region

width is large under normal condition, it carriers small reverse current due to the minority

charge carriers in µA.

If the photo diode is forward bias the current flow through it is in mA. The applied

forward bias voltage takes the control of current instead of light. The change in current due to

light is negligible and cannot be noticed. The resistance of forward bias diode is not affected

by the light, hence to have significant effect of light on the current and to operate photo diode

as a variable resistor, it is always operated or connected in reverse bias.

When there is no light, it is called as dark current because there is no current flow due

to the infinite resistance. When there is a light more current flows due to very less resistance.

Under reverse bias current control due to light only instead of applied voltage.



PHOTO TRANSISTOR:

The photo transistor has a light sensitive collector to base junction. A lens is used in

transistor package to expose to an incident light.

When no light is incident, a small leakage current flow from collector to emitter called

ICEO, due to small thermal generation. This is very small current of the order of nA, this is

called a Dark current.

When the base is exposed to the light, the base current is produced which is

proportional to the light intensity. As light intensity increases, the base current increases

exponentially. Similarly the collector current also increases corresponding to the increase in

the light intensity.

Photo transistor can be both a two lead(and) three lead devices. For two lead devices,

the base is not electrically available and the device use is totally light dependent.

Procedure:

Photodiode:


2. Photo diode is placed at a particular distance from the illumination.

3. The voltage is varied using RPS and the corresponding current is noted.

4. Readings are tabulated for various distance and the graph is drawn between voltage and

current.

Photo transistor:


2. Photo transistor is placed at a particular distance from the illumination.

3. Voltage is varied using RPS and the corresponding current id noted.

4. Readings are tabulated for various distance and the graph is drawn between voltage and

current.



Circuit Diagram:

Photodiode:

Photo Transistor:



Model Graph:

Tabulation: Photodiode:

d1=5cm d1=10cm

Voltage (V) Current (µA) Voltage (V) Current (µA)

Photo transistor:

d1=5cm d1=10cm

Voltage (V) Current (mA) Voltage (V) Current (mA)



Result:

Thus the characteristics of photodiode and photo transistor have been studied and

determined the diode voltage and current at different level of illumination.



EXPT NO:14 BRIDGE RECTIFIER WITH FILTER AND WITHOUT

FILTER

AIM:

1. To plot input and output waveforms of the Bridge Rectifier with and without Filter

2. To find ripple factor for Bridge Rectifier with and without Filter

3. To find Regulation factor for Bridge Rectifier with and without Filter

Apparatus

INTRODUCTION:

A device is capable of converting a sinusoidal input waveform into a unidirectional waveform

with non zero average component is called a rectifier. The Bridge rectifier is a circuit, which

converts an ac voltage to dc voltage using both half cycles of the input ac voltage. The Bridge

rectifier has four diodes connected to form a Bridge. The load resistance is connected between

the other two ends of the bridge. For the positive half cycle of the input ac voltage, diode D1

and D3 conducts whereas diodes D2 and D4 remain in the OFF state. The conducting diodes

will be in series with the load resistance RL and hence the load current flows through RL . For

the negative half cycle of the input ac voltage, diode D2 and D4 conducts whereas diodes D1

and D3 remain in the OFF state. The conducting diodes will be in series with the load

resistance RL and hence the load current flows through RL in the same direction as in the

previous half cycle. Thus a bidirectional wave is converted into a unidirectional wave.



Circuit Diagram

Without Filter

With Filter

Theoretical calculations for Ripple factor:-



Experiment (without filter)

1. Connections are made as per the circuit diagram of the rectifier without filter.

2. Connect the primary side of the transformer to ac mains and the secondary side to the

rectifier input.

3. By the multimeter, measure the ac input voltage of the rectifier and, ac and dc voltage at the

output of the rectifier.

4. Measure the amplitude and timeperiod of the transformer secondary(input waveform) by

connecting CRO.

5. Feed the rectified output voltage to the CRO and measure the time period and amplitude of

the waveform.

Experiment (With filter)

1. Connections are made as per the circuit diagram of the rectifier with filter.

2. Connect the primary side of the transformer to ac mains and the secondary side to the

rectifier input.

3. By the multimeter, measure the ac input voltage of the rectifier and, ac and dc voltage at the

output of the rectifier.

4. Measure the amplitude and timeperiod of the transformer secondary(input waveform) by

connecting CRO.

5. Feed the rectified output voltage to the CRO and measure the time period and amplitude of

the waveform. Tabular Column: Without Filter Using DMM:



Tabular Column: Without Filter

Using DMM:

Using CRO : VNL=



Model Graph:



PRECAUTIONS:

1. The primary and secondary sides of the transformer should be carefully identified.

2. The polarities of the diode should be carefully identified.

Result:

The input and output waveforms of Bridge wave rectifier is plotted and the ripple factor and

regulation at 1100Ω are

Ripple factor with out Filter =

Ripple factor with Filter =

% Regulation =

Documents

DMI COLLEGE OF ENGINEERINGdmice.ac.in/wp-content/uploads/2017/05/EC6211.pdf · 2018-12-24 · EC6211-Circuits and devices Lab Dept of Electronics & Communication Engg DMI college