asd asd asd DEPARTMENT OF ELECTRICAL & ELECTRONICS ENGINEERING VISION

 To strengthen the department into a center of academic excellence with focus on advanced technology and research by delivering the best quality technical education to the students in meeting the current and future challenges with emphasis on moral and ethical foundation.

MISSION  To create and enrich academic environment with essential resources, so as to train and mould students to promote active learning, critical thinking with innovative ideas to solve real-world problems in the field of Electrical Engineering.

 To motivate and strengthen faculty to practice effective teaching learning process and advanced research and publication work.

 To enhance industry interaction and initiate best consultancy services.

PROGRAMME EDUCATIONAL OBJECTIVES (PEOs) PEO1: Excellence in Career To provide students with in -depth knowledge in the fundamental and advanced areas of electrical and electronics engineering and there by excel in professional career and higher education.

PEO2: Development of Research and Industry Interaction To train students in the software/hardware design of electrical systems and promote the development of research activity as well as interaction with the industry.

PEO3: Professional and Ethical Attitude To inculcate professional and ethical attitude in students and enhance the ability to relate engineering issues to broader social context.

PROGRAM SPECIFIC OUTCOMES (PSOs) After the completion of the course, B. Tech Electrical & Electronics Engineering, the graduates will have the following Program Specific Outcomes:

PSO1: To make students strong in core and advanced subjects of electrical and electronics engineering by which they can excel in their future endeavors.

PSO2 : To make students exposed to latest simulation tools of electrical systems and provid e a sense of direction towards research and industry interaction.

PSO3 : To make the students handle social related engineering issues without deviating from professional and ethical values PROGRAM OUTCOMES (POs) Engineering Graduates should possess the following:

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 and management principles and apply these to one’s own work, as a member and leader in a team, to manage projects and in multi -disciplinary environments.

12. Life- long learning : Recognize the need for, and have the preparation and ability to engage in independent and life -long learning in the broadest context of technological change.

MALLA REDDY COLLEGE OF ENGINEERING & TECHNOLOGY Maisammaguda, Dhulapally Post, Via Hakimpet, Secunderabad – 500100 DEPARTMENT OF ELECTRICAL &ELECTRONICS ENGINEERING GENERAL LABORATORY INSTRUCTIONS  Before entering the lab the student should carry the following things.

o Identity card issued by the college.

o Class notes o Lab observation book o Lab Manual o Lab Record  Student must sign in and sign out in the register provided when attending the lab session

without fail.

 Come to the laboratory in time. Students, who are late more than 15 min., will not be allowed to attend the lab.

 Students need to maintain 100% attendance in lab if not a strict action will be taken.

 All students must follow a Dress Code while in the laboratory  Foods, drinks are NOT allowed.

 All bags must be left at the indicated place.

 The objective of the laboratory is learning. The experiments are designed to illustrate phenomena in different areas of Physics and to expose you to measuring instruments, conduct the experiments with interest and an attitude of learning  You need to come well prepared for the experiment.

 Work quietly and carefully  Be honest in recording and representing your data.

 If a particular reading appears wrong repeat the measurement carefully, to get a better fit for a graph  All presentations of data, tables and graphs calculations should be neatly and carefully done  Graphs should be neatly drawn with pencil. Always label graphs and the axes and display units.

 If you finish early, spend the remaining time to complete the calculations and drawing graphs. Come equipped with calculator, scales, pencils etc.

 Do not fiddle with apparatus. Handle instruments with care. Report any breakage to the Instructor. Return all the equipment you have signed out for the purpose of your experiment.

HEAD OF THE DEPARTMENT PRINCIPAL MALLA REDDY COLLEGE OF ENGINEERING AND TECHNOLOGY I YEAR B.Tech I -SEM L/T/P/C -/-/3/1.5 (R22A0281)PRINCIPLES OF ELECTRICAL AND ELECTRONICS ENGINEERING LAB

COURSE OBJECTIVES:

1. To design an electrical systems.

2. To analyze a given network by applying various circuit laws and network theorems.

3. To expose the students to the operation of DC machine and transformer.

4. To exhibit the students to the operation of PN junction diode and Zener diode.

5. To expose the s tudents to the operation of Rectifier.

Among the following experiments any 10 are to be conducted 1. Verification of KVL and KCL.

2. Verification of Thevenin’s theorem.

3. Verification of Norton’s theorem.

4. Verification of Super position theorem.

5. Magnetization characteristics of DC shunt generator.

6. Speed control of DC shunt motor using armature control method.

7. Speed control of DC shunt motor using flux control method 8. Load test on single phase transformer.

9. PN Junction diode characteristics.

10. Zener diode characteristics.

11. Half wave rectifier.

12. Full wave rectifier.

COURSE OUTCOMES:

At the end of the course, students would be able to 1. Explain the concept of circuit laws and network theorems and apply them to laboratory measurements.

2. Be able to systematically obtain the equations that characterize the performance of an electric circuit as well as solving them.

3. Perform the required tests on transformers and DC motors.

4. Plot the characteristics of Zener diodes.

5. Determine the working of rectifiers in detail.

CONTENTS S. No Name of the Experiment Page Number 1 Verification of KVL and KCL. 1-7 2 Verification of Thevenin’s theorem. 8-15

3 Verification of Norton’s theorem. 16-22 4 Verification of Superposition theorem. 23-25 5 Magnetization characteristics of DC shunt generator 26-31 6 Speed control of DC shunt motor using armature control method.

32-56 7 Speed control of DC shunt motor using flux control method 57-69 8 Load test on single phase transformer. 70-74 9 PN Junction diode characteristics. 75-86

10 Zener diode characteristics.

87-95 11 Half wave rectifier. 96-101 12 Full wave rectifier.

102-110 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 1 1. VERIFICATION OF KIRCHHOFF’S LAWS AIM: To verify the Kirchhoff’s voltage law and Kirchhoff’s current law for the given circuit.

APPARATUS REQUIRED:

S.No Name of the equipment Range Type Quantity 1 RPS 0-30V - 1N0 2 Voltmeter 0-20 V Digital 4 NO 3 Ammeter 0-20m a Digital 4 NO

4 Bread board - - 1 NO 5 Connecting wires - - Required Number.

6 Resistors 470 Ω 2 NO 1KW 1 NO 680Ω 1 NO CIRCUIT DIAGRAMS:

GIVEN CIRCUIT:

Fig (1) 1. KVL:

Fig (1a) DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 2 PRACTICAL CIRCUIT:

2. KCL:

PRACTICAL CIRCUIT:

Fig (2b) DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 3 THEORY:

a) Kirchhoff’s Voltage law states that the algebraic sum of the voltage around any closed path in a given circuit is always zero. In any circuit, voltage drops across the resistors always have polarities opposite to the source polarity. When the current passes through the resistor, there is a loss in energy and therefo re a voltage drop. In any element, the current flows from a higher potential to lower potential. Consider the fig

(1a) shown above in which there are 3 resistors are in series. According to kichhoff’s voltage law….

V = V1 + V2 + V3 b) Kirchhoff’s current law states that the sum of the currents entering a node equal to the sum of the currents leaving the same node. Consider the fig (1b) shown above in which there are 3 parallel paths. According to Kirchhoff’s current law...

I = I1 + I2 + I3 PROCEDURE:

1. Kirchhoff’s Voltage law:

a) Connect the circuit as shown in fig (2a).

b) Measure the voltages across the resistors.

c) Observe that the algebraic sum of voltages in a closed loop is zero.

2. Kirchhoff’s current law:

a) Connect the circuit as shown in fig (2b).

b) Measure the currents through the resistors.

c) Observe that the algebraic sum of the currents at a node is zero.

CALUCULATIONS:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 4 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 5 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 6 OBSERVATION TABLE:

KVL:

S.NO Resistor Voltage across the resistor Theoretical Practical KCL:

S.NO Resistor Current through the resistor Theoretical Practical PRECAUTIONS:

1. Avoid loose connections.

2. Keep all the knobs in minimum position while switch on and off of the supply.

RESULT:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 7 EXERCISE QUESTIONS:

1. In the Circuit Given In Fig . Find A)The Current I B)The Voltage Across 30 Ω resistance 2. Determine The Current In All Resistors In The Circuit Shown In Fig.

VIVA QUESTIONS:

1. What is another name for KCL & KVL?

2. Define network and circuit?

3. What is the property of inductor and capacitor?

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 8 2. VERIFICATION OF THEVENIN’S THEOREM AIM: To verify Thevenin’s theorem for the given circuit.

APPARATUS REQUIRED:

S. No Name of The Equipment Range Type Quantity 1 Voltmeter (0-20)V Digital 1 NO 2 Ammeter (0-20)mA Digital 1 NO 3 RPS 0-30V Digital 1 NO 4

Resistors 10K Ω,1K Ω 1 NO 2.2Ω 1 NO 330 Ω 1 NO 5 Breadboard - - 1 NO 6 DMM - Digital 1 NO

7 Connecting wires Required number CIRCUIT DIAGRAM:

GIVEN CIRCUIT:

PRACTICAL CIRCUIT DIAGRAMS:

TO FIND IL:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 9 IL from T hevenins equivalent circuit:

THEORY:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 10 THEVENIN’S THEOREM:

It states that in any lumped, linear network having more number of sources and elements the equivalent circuit across any branch can be replaced by an equivalent circuit consisting of Theremin’s equivalent voltage source V th in series with Theremin’s equivalent resistance R th.

Where V th is the open circuit voltage across (branch) the two terminals and R th is the resistance seen from the same two terminals by replacing all other sources with internal resistances.

PROCEDURE:

1. Connect the circuit as per fig (1) 2. Adjust the output voltage of the regulated power supply to an appropriate value (Say 20V).

3. Note down the response (current, IL) through the branch of interest i.e. AB (ammeter reading).

4. Reduce the output voltage of the regulated power supply to 0V and switch -off the supply.

5. Disconnect the circuit and connect as per the fig (2).

6. Adjust the output voltage of the regulated power supply to 20V.

7. Note down the voltage across the load terminals AB (Voltmeter reading) that gives Vth.

8. Reduce the output voltage of the regulated power supply to 0V and switch -off the supply.

9. Disconnect the circuit and connect as per the fig (3).

10. Connect the digital multimeter(DMM) across AB terminals and it should be kept in DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 11 resistance mode to measure Thevenin’s resistance(R Th).

CALCULATIONS:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 12 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 13 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 14 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 15 THEORITICAL VALUES:

Tabulation for Thevenin’s Theorem:

THEORITICAL VALUES PRACTICAL VALUES Vth= Rth= IL= Vth=

Rth= IL= RESULT:

EXERCISE QUESTIONS:

1. Determine current through current 5 ohms resistor using Norton’s theorem.

2. Determine the current flowing through the 5 ohm resistor using Thevenin’s theorem VIVA QUESTIONS:

1) The internal resistance of a source is 2 Ohms and is connected with an External Load Of 10 Ohms Resistance. What is Rth ?

2) In the above question if the voltage is 10 volts and the load is of 50 ohms What is the load current and Vth? Verify IL?

3) If the internal resistance of a source is 5 ohms and is connected with an External Load Of 25 Ohms Resistance. What is Rth?

4) In the above question if the voltage is 20V and the load is of 50 Ohms, What is the load current and IN ? Verify IL ?

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 16 3. VERIFICATION OF NORTON’S THEOREM AIM: To verify Norton’s theorem for the given circuit.

APPARATUS REQUIRED:

S. No Name Of The Equipment Range Type Quantity 1 Voltmeter (0-20)V Digital 1 NO 2 Ammeter (0-20)mA Digital 1 NO 3 RPS 0-30V Digital 1 NO 4

Resistors 10K Ω,1K Ω 1 NO 2.2Ω 1 NO 330 Ω 1 NO 5 Breadboard - - 1 NO 6 DMM - Digital 1 NO

7 Connecting wires Required number CIRCUIT DIAGRAM:

GIVEN CIRCUIT:

PRACTICAL CIRCUIT DIAGRAMS:

TO FIND IL:

TO FIND IN:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 17 fig (2) THEORY:

NORTON’S THEOREM:

Norton’s theorem states that in a lumped, linear network the equivalent circuit across any branch is replaced with a current source in parallel a resistance. Where the current is the Norton’s current which is the short circuit cu rrent though that branch and the resistance is the Norton’s resistance which is the equivalent resistance across that branch by replacing all the sources with their internal resistances

FOR NORTON’s CURRENT Load Current through Load Resistor IL = IN x [RN / (RN+ RL)] DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 18

PROCEDURE:

1. Connect the circuit as per fig (1) 2. Adjust the output voltage of the regulated power supply to an appropriate value (Say 20V).

3. Note down the response (current, IL) through the branch of interest i.e. AB (ammeter reading).

4. Reduce the output voltage of the regulated power supply to 0V and switch -off the supply.

5. Disconnect the circuit and connect as per the fig (2).

6. Adjust the output voltage of the regulated power supply to 20V.

7. Note down the response (current, IN) through the branch AB (ammeter reading).

8. Reduce the output voltage of the regulated power supply to 0V and switch -off the supply.

9. Disconnect the circuit and connect as per the fig (3).

10. Connect the digital Multimeter (DMM) across AB terminals and it should be kept in resistance mode to measure Norton’s resistance (R N).

CALCULATIONS:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 19 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 20 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 21 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 22 TABULATION FOR NORTON’S THEOREM:

THEORITICAL VALUES PRACTICAL VALUES IN= RN= IL= IN=

RN= IL= RESULT:

EXERCISE QUESTIONS:

1. Determine current through current 5 ohms resistor using Norton’s theorem.

2. Determine the current flowing through the 5 ohm resistor using Thevenin’s theorem VIVA QUESTIONS:

1) The internal resistance of a source is 2 Ohms and is connected with an External Load Of 10 Ohms Resistance. What is Rth?

2) In the above question if the voltage is 10 volts and the load is of 50 ohms. What is the load current and Vth? Verify IL?

3) If the internal resistance of a source is 5 ohms and is connected with an External Load Of 25 Ohms Resistance. What is Rth?

4) In the above question if the voltage is 20V and the load is of 50 Ohms. What is the load current and IN ? Verify IL ?

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 23 4. VERIFICATION OF SUPERPOSITION THEOREM AIM: To verify the superposition theorem for the given circuit.

APPARATUS REQUIRED:

S.No Name of The Equipment Range Type Quantity 1 Bread board - - 1 NO 2 Ammeter (0-20) mA Digital 1 NO 3 RPS 0-30V Digital 1 NO 4

Resistors 2.2k Ω 1 NO 1k Ω 1 NO 560 Ω 1 NO 5 Connecting Wires - - As required CIRCUIT DIAGRAM:

PRACTICAL CIRCUITS:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 24 L L L

L When V 1 Source Acting (To Find I I) Fig (2) When V2 source acting (To find I II):

Fig (3) THEORY:

SUPERPOSITION THEOREM:

Superposition theorem states that in a lumped ,linear, bilateral network consisting more number of sources each branch current(voltage) is the algebraic sum all currents ( branch voltages), each of which is determined by considering one source at a time and removing all other sources. In removi ng the sources, voltage and current sources are replaced by internal resistances.

PROCEDURE:

1. Connect the circuit as per the fig (1).

2. Adjust the output voltage of sources X and Y to appropriate values (Say 15V and20V respectively).

3. Note down the current (IL) through the 560 0hm resistor by using the ammeter.

4. Connect the circuit as per fig (2) and set the source Y (20V) to 0V.

5. Note down the current ( I l) through 560ohm resistor by using ammeter .

6. Connect the circuit as per fig (3) and set the source X (15V) to 0V and source Y to 20V.

7. Note down the current (I ll) through the 560 ohm resistor branch by using ammeter.

8. Reduce the output voltage of the sources X and Y to 0V and switch off the supply.

9. Disconnect the circuit .

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 25 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 26 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 27 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 28 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 29

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 30 TABULAR COLUMNS:

PRECAUTIONS:

1. Initially keep the RPS output voltage knob in zero volt position.

2. Set the ammeter pointer at zero position.

3. Take the readings without parallax error.

4. Avoid loose connections.

5. Avoid short circuit of RPS output terminals.

RESULT:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 31 EXERCISE QUESTIONS:

VIVA QUESTIONS:

1) What do you mean by Unilateral and Bilateral network? Give the limitations of Superposition Theorem?

2) What are the equivalent internal impedances for an ideal voltage source and for a Current source?

3) Transform a physical voltage source into its equivalent current source.

4) If all the 3 star connected impedance are identical and equal t o ZA, then what is the Delta connected resistors DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 32 20

A Rheostat 5(a). MAGNETIZATION CHARACTERISTICS OF D.C SHUNT GENERATOR AIM:

To obtain the no load characteristics of a DC shunt generator and to determine the critical field resistance.

NAME PLATE DETAILS:

S.NO Characteristics D.C Motor D.C Generator 1 Voltage 220V 220V 2 Current 13.6A 20A 3 Speed 1500rpm 1500rpm 4 Power 5HP 3KW

APPARATUS REQUIRED:

S.NO Name of The Equipment Type Range Quantity 1 Voltmeters MC 0-300V 2NO 2 Ammeters MC 0-2A 1NO 3 Rheostats WW 370 Ω /2A 2NO

4 Tachometers Digital 0-10000rpm 1NO CIRCUIT DIAGRAM:

20 A Motor Generator DPSTS: Double Pole Single through Switch L – LINE F- FIELD A – ARMATURE

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 33 THEORY:

Magnetization curve is relation between the magnetizing forces and the flux density B. this is also expressed as a relation between the field current and the induced e.m.f, in a D.C machine. Varying the field current and noting corresponding values of induced e.m.f can determine this. For a self -excited machine the theoretical shape of the magnetization Curve is as shown in the figure. The induced e.m.f corresponding to residual magnetism exis ts when

the field current is zero. Hence the curve starts, a little above the origin on y -axis. The field resistance line R sh is a straight -line passing through the origin.

If field resistance is increased so much that the resistance line does not cut the OCC at all then obviously the machine will fail to excite .If the resistance line just lies along the slope, then machine will just excite. The value of the resistance represented by the tangent to the curve is known as critical field resistance Rc for a given speed.

CRITICAL FIELD RESISTANCE: it is the resistance of the field winding of the generator below which generator fail to build up the voltage.

First OCC is plotted from the the readings then tangent is drawn to its initial position .The slope of this curve gives the critical field resistance.

From the graph the critical field resistance Rc = AB/BC.

PROCEDURE:

1. Connect the circuit as per the circuit diagram shown in fig.

2. Keep the motor field rheostat Rsh at minimum position and generator field rheostat at maximum position.

3. Switch on the DPST swatch. Start the motor slowly by using starter.

4. Adjust the current so that the motor runs at its rated speed.

5. Now vary the generator field rheostat to increase the field current and take the no load voltage and field current readings.

6. Take the no load voltage values until field gets saturated.

7. Finally set the field rheostats to initial positions then switch off the supply.

8. Draw the graph between generated voltage and field current. Find the critical field resistance from the tangent line.

CALCULATIONS:

Critical resistance R c = ∆E0 / ∆If = ohms DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 34 TABULAR COLUMN:

Residual Voltage = Speed= SNO If(A) Eg(V) DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 35 MODEL GRAPH:

Draw the graph between generated voltage at no load and field current. By taking Generated voltage Eg in volts on Y axis and field current If in amps on X-axis.

PRECAUTIONS:

1) The rheostat is connected such that minimum resistance is included in field circuit of motor.

2) The rheostat is connected such that maximum resistance is included in field circuit of generator.

3) Starter handle is moved slowly.

RESULT:

VIVA QUESTIONS:

1. What is meant by critical field resistance?

2. Residual magnetism is necessary for self excited generators or not.

3. Why this test is conducted at constant speed?

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 36 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 37 5(b). MAGNETIZATION CHARACTERISTICS OF DC SHUNT GENERATOR

AIM: To obtain magnetization characteristics of a DC shunt generator & to find its critical resistance at constant rated speed.

NAME PLATE DETAILS:

Term D .C Shunt Motor D.C Shunt Generator Power 5 H.P , 3.7KW 3KW Voltage 220V 220V Current 19A 19A Speed 1500RPM 1500RPM

Field current 1A 1A FUSE RATING:

Motor side:

125% of rated current of DC Motor 125 X19/100=23.75≈ 25 A APPARATUS REQUIRED:

S. No Name of the Apparatus Range Type Quantity Availability 1 Ammeter (0-2)A Digital 1 On Panel 2 Voltmeter (0-300)V Digital 1 On Panel

3 Rheostats 370Ω,1.7A Wire Wound 2 External 4 RPM meter (0-9999)rpm Digital 1 On Panel 5 Connecting

Wires - - As Required External TEST SETUP:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 38 PANEL:

PROCEDURE:

1. Connections are made as per the circuit diagram.

2. Before starting the motor, ensure that both field rheostat and Pot meter of Drive Control Unit are in minimum position and the field rheostat of Generator should be in its maximum position.

Similarly the load resistance connected to the Generator should be in its minimum position (No load).

3. Observing all the precautions, the motor is started using Drive Control Unit and the speed is increased until the rated armature voltage (of motor) is reached. At this instant the speed would be slightly lesser than the rated speed.

4. Now by adjusting the field rheostat, the motor is brought to the rated speed.

5. Now the field Rheostat of generator is varied and the field resistance is gradually decreased in steps thus increasing the field current. At each step the field current ( If) and the corresponding induced EMF (Eg) are recorded in the tabular column. This procedure is continued until the generator voltage reaches its rated value.

6. Note: While conducting the experiment the machine is maintained at constant speed.

7. After the experiment is completed the various rheostats are brought back to their original position in sequence and then main supply is switched off.

PRECAUTIONS:

1. The field rheostat of motor should be in minimum resistance position at the time of starting to start the machine from minimum speed.

2. The field rheostat of generator should be in maximum resistance position at the time of starting and stopping the machine.

3. Residual voltage should be taken under no field current.

4. The characteristics should be drawn at constant rated speed by adjusting the drive unit or motor filed resistance as required.

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 39 OBSERVATIONS:

Rsh = ohms Sl. No Field Current If (Amps) Armature Voltage Eo (Volts) 1 2 3

4 5 6 7 8

9 10 CRITICAL FIELD RESISTANCE:

It is that value of the field resistance at which the D.C. shunt generator will fail to excite.

Critical field resistance is obtained by plotting the OCC as in fig.1 and drawing a tangent to the linear position of the curve from the origin. Then critical resistance is given by the slope of that tangent. While drawing the tangent, the initial position of the O.C.C is neglected.

MODEL GRAPH:

Fig.1 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 40 CALCULATIONS:

Critical resistance R c = ∆E0 / ∆If = ohms VIVA QUESTIONS:

1. What is the principle of generator?

2. What is meant by residual magnetism?

3. What is critical field resistance?

4. What is meant by saturation?

5. What is the difference between a separately excited dc generator and shunt generator?

6. If a DC shunt generator fails to build up voltage, what may be the probable reasons?

7. What is SPST? What is its use in this experiment?

8. What is the reason for the presence of residual magnetism in the field poles?

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 41 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 42 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 43 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 44 RESULT:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 45 6a. SPEED CONTROL OF DC SHUNT MOTOR USING ARMATURE CONTROL METHOD Aim:- To conduct the speed control of dc shunt motor by using Armature control method.

Apparatus Required: - S.NO NAME RANGE TYPE QUANTITY 1 Voltmeter (0-300)V MC 1NO 2 Ammeter (0-20)A MC 1NO 3 Ammeter (0-2)A MC 1NO

4 Rheostat 370Ω, 1.7A Wire wound 1NO 5 Tachometer (0-10,000) RPM Digital 1NO 6 Connecting wires -- - Required Name plate details :- S.NO Characteristics D.C Motor

1 Voltage 220V 2 Current 13.6A 3 Speed 1500rpm 4 Power 5HP Circuit diagram

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 46 Procedure: - 1. Connect the circuit as per the circuit diagram.

2. Ensure that the motor armature rheostat should be in maximum resistance position.

3. Give the dc supply to the machine by closing the DPST switch and start the motor with the help of three point starter.

4. By decreasing the resistance of rheostat, note down the readings of armature voltage and speed of the shunt motor.

5. Repeat the step no.4 till rated speed is obtained.

6. Switch off the dc supply by opening the DPST switch.

Tabular columns: - Model graphs: - S.NO Voltage across the armature(volts) Speed(r.p.m) 1

2 3 4 5 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 47 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 48 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 49

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 50 Result :

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 51 6b. SPEED CONTROL OF DC SHUNT MOTOR USING ARMATURE CONTROL METHOD AIM:

To control the speed of DC shunt motor using Armature control.

NAME PLATE DETAILS:

Term D .C Shunt Motor Power 5 H.P , 3.7KW Voltage 220V Current 20A Speed 1500RPM

Field current 1A FUSE RATING:

Motor and Generator side:

125% of rated current of DC Motor 125*20/100= 25 A APPARATUS REQUIRED:

S.No: Name of the Apparatus Range Type Quantity Availability 1 Ammeter (0-2)A (0-20) A Digital Digital 1

1 On Panel On Panel 2 Voltmeter (0-300)V Digital 1 On Panel 3 Rheostat 370/1.7A Wire Wound 1 External 4 RPM meter (0-9999)rpm Digital 1 On Panel

5 Connecting Wires - - As Required External DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 52 TEST SETUP:

PANEL:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 53 PROCEDURE:

1. Connections are made as per the circuit diagram.

2. Before starting the motor, Ensure that the field rheostat and Pot meter of Drive Control Unit are in minimum position.

3. Observing all the precautions and the motor is started using drive control unit and the speed is increased until the rated armature voltage is reached 4. The motor field rheostat is then ad justed until the motor runs at rated speed 5. The motor is now ready to work at rated armature voltage and rated speed.

6. Now to get variable speeds by AVC method, the field current (I f) is kept constant value and the potentiometer of drive control unit is adj usted to get various below base speeds.

7. Note down the corresponding armature voltages and motor speeds.

8. This procedure is repeated for different values of field current.

OBSERVATIONS:

Sl.

No: If1 = If2 = Armature Voltage Va ( Volts) Speed

N (rpm) Armature Voltage Va ( Volts) Speed N (rpm) 1.

2.

3.

4.

5.

6.

7.

8.

PRECAUTIONS:

1. Field Rheostat should be kept in the minimum resistance position at the time of starting and stopping the motor.

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 54 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 55 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 56 MODEL GRAPH :

Result:

VIVA QUESTIONS:

1. What are Factors determining the Speed of a Dc Motor?

2. How the speed control can be achieved by above rated speed control method?

3. What is the minimum speed limit of given machine 4. How the speed control can be achieved by below rated speed control method?

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 57 7a. SPEED CONTROL OF DC SHUNT MOTOR USING FLUX CONTROL METHOD Aim:- To conduct the speed control of dc shunt motor by using flux control method.

Apparatus Required: - S.NO NAME RANGE TYPE QUANTITY 1 Voltmeter (0-300)V MC 1NO 2 Ammeter (0-20)A MC 1NO 3 Ammeter (0-2)A MC 1NO

4 Rheostat 370Ω, 1.7A Wire wound 1NO 5 Tachometer (0-10,000) RPM Digital 1NO 6 Connecting wires -- - Required Name plate details :- S.NO Characteristics D.C Motor

1 Voltage 220V 2 Current 13.6A 3 Speed 1500rpm 4 Power 5HP Circuit diagram

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 58 Procedure: - 1 .Connect the circuits as per the circuit diagram.

2. Ensure that the motor field rheostat should be in minimum resistance position.

3. Give the dc supply to the machine by closing the DPST switch and start the motor with the help of three point starter.

4. By increasing the resistance of field rheostat, note down the readings of field current and speed of the shunt motor.

5. Repeat the step no.4 till about 130% of rated speed is obtained.

6. Switch off the dc supply by opening the DPST switch .

Tabular column :- Model graph :- S.NO Field current(A) Speed(r.p.m) 1

2 3 4 5 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 59 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 60 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 61

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 62 Result:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 63 7b. SPEED CONTROL OF DC SHUNT MOTOR USING FLUX CONTROL METHOD AIM:

To control the speed of DC shunt motor flux control NAME PLATE DETAILS:

Term D .C Shunt Motor Power 5 H.P , 3.7KW Voltage 220V Current 20A Speed 1500RPM

Field current 1A FUSE RATING:

Motor and Generator side:

125% of rated current of DC Motor 125*20/100= 25 A APPARATUS REQUIRED:

S.No: Name of the Apparatus Range Type Quantity Availability 1 Ammeter (0-2)A (0-20) A Digital Digital 1

1 On Panel On Panel 2 Voltmeter (0-300)V Digital 1 On Panel 3 Rheostat 370/1.7A Wire Wound 1 External 4 RPM meter (0-9999)rpm Digital 1 On Panel

5 Connecting Wires - - As Required External DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 64 TEST SETUP:

PANEL:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 65 PROCEDURE:

1. The pot meter of Drive Control Unit is adjusted to maintain constant rated armature voltage.

2. Now the field rheostat is varied in steps so as to decrease the field current. Corresponding motor speeds and field currents are noted.

3. This procedure is repeated for reduced armature voltage (Lesser than the rated armature voltage).

After the experiment is completed the various rheostats are brought back to their orig inal position in sequence and then main supply is switched off PRECAUTIONS:

1. Field Rheostat should be kept in the minimum resistance position at the time of starting and stopping the motor.

OBSERVATIONS:

Sl.

No: Va1 = Va2 = Field Current If (A) Speed

N (rpm) Field Current If (A) Speed N (rpm) 1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 66 MODEL GRAPH:

RESULT:

VIVA QUESTIONS:

1. What are Factors determining the Speed of a Dc Motor?

2. How the speed control can be achieved by above rated speed control method?

3. What is the minimum speed limit of given machine 4. How the speed control can be achieved by below rated speed control method?

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 67 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 68 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 69 RESULT:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 70 8. LOAD TEST ON 1-PHASE TRANSFORMER AIM : To find out efficiency by conducting the load test on 1- Transformer.

APPARATUS REQUIRED:

S.NO APPARATUS TYPE RANGE QUANTITY 1 1- AUTO Transformer - 0-230V/270V 01 2 1- Transformer Shell type 220/110V 01 3 Voltmeter MI 0-300V 02

4 Ammeter MI 0-20A 02 5 Resistive load - 0-20A 01 6 Wattmeter UPF 300V/20A 01 7 Connecting wires Required number

CIRCUIT DIAGRAM:

RESISTIVE LOAD:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 71 PROCEDURE:

1) Connect the circuit as shown in above fig.

2) Switch on the input AC supply.

3) Slowly vary the auto transformer knob up to rated input voltage of main transformer.

4) Apply the load slowly up to rated current of the transformer.

5) Take down the voltmeter and ammeter readings.

6) Draw the graph between efficiency and output power.

TABULAR COLUMN (RESISTIVE LOAD):

S.NO Load Current (amps) Resistive Load

PRIMARY SIDE (Wi) SECONDARY SIDE (Wo) %Efficiency (η) =

(Wo/Wi)*100 MODEL GRAPH:

EFFICIENCY VS OUTPUT DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 72 %EFFICIENCY = OUTPUT POWER / INPUT POWER (W o/W i)*100 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 73 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 74 RESULT:

VIVA QUESTIONS:

1) What is load test on transformer and what is the advantage of this test?

2) What is other test to determine the efficiency and regulation of transformer?

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 75 9. P-N JUNCTION DIODE CHARACTERISTICS AIM:

1. To observe and draw the Forward and Reverse bias V -I Characteristics of a P -N Junction diode.

2. To calculate static and dynamic resistance in both forward and Reverse Bias Conditions.

APPARATUS:

1. P-N Diode IN4007 - 1No.

2. Regulated Power supply (0-30V) - 1No.

3. Resistor 1KΩ - 1No.

4. Ammeter (0-20 mA) - 1No 5. Ammeter (0-200µA) - 1No.

6. Voltmeter (0-20V) - 2No.

7. Bread board - 1No.

8. Connecting wires THEORY:

A P-N junction diode conducts only in one direction. The V-I characteristics of the diode are curve between voltage across the diode and current flowing through the diode. When external voltage is zero, circuit is open and the potential barrier does not allow the current to flow. Therefore, the circuit current is zero. When P-type (Anode) is connected to +ve terminal and n - type (cathode) is connected to –ve terminal of the supply

voltage is known as forward bias. The potential barrier is reduced when diode is in the forward biased condition. At some forward voltage, the potential barrier altogether eliminated and current starts flowing through the diode and also in the circuit. Then diode is said to be in ON state. The current increases with increasing forward voltage.

When N-type (cathode) is connected to +ve terminal and P-type (Anode) is connected –ve terminal of the supply voltage is known as reverse bias and the potential barrier across the junction increases. Therefore, the junction resistance becomes very high and a very small current (reverse saturation current) flows in the circuit. Then diode is said to be in OFF state .

The reverse bias current is due to minority charge carriers.

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 76 CIRCUIT DIAGRAM:

A) Forward bias:

B) Reverse Bias:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 77 MODEL GRAPH:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 78 OBSERVATIONS:

A) FORWARD BIAS:

S.NO Applied Voltage(V) Forward Voltage(V f) Forward Current(I f(mA)) DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 79 B) REVERSE BIAS:

S.NO Applied Voltage(V) Reverse Voltage(V R) Reverse Current(I R(µA)) DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 80 Calculations:

Calculation of Static and Dynamic Resistance for a given diode.

In forward bias condition:

Static Resistance , Rs = Vf/I f = Dynamic Resistance, RD = ∆Vf/ ∆If = In Reverse bias condition:

Static Resistance , Rs = VR/IR = Dynamic Resistance, RD = ∆VR/ ∆IR = PROCEDURE:

A) FORWARD BIAS:

1. Connections are made as per the circuit diagram.

2. For forward bias, the RPS +ve is connected to the anode of the diode and RPS –ve is connected to the cathode of the diode 3. Switch on the power supply and increases the input voltage (supply voltage) in Steps of 0.1V 4. Note down the corresponding current flowing through the diode and

voltage across the diode for each and every step of the input voltage.

5. The reading of voltage and current are tabulated.

6. Graph is plotted between voltage (Vf) on X-axis and current (If) on Y-axis.

B) REVERSE BIAS:

1. Connections are made as per the circuit diagram 2. for reverse bias, the RPS +ve is connected to the cathode of the diode and RPS –ve is connected to the anode of the diode.

3. Switch on the power supply and increase the input voltage (supply voltage) in Steps of 1V.

4. Note down the corresponding current flowing through the diode voltage across the diode for each and every step of the input voltage.

5. The readings of voltage and current are tabulated 6. Graph is plotted between voltage (VR) on X-axis and current (IR) on Y-axis.

PRECAUTIONS:

1. All the connections should be correct.

2. Parallax error should be avoided while taking the readings from the Analog meters.

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 81 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 82 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 83 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 84 RESULT:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 85 EXERCISE QUESTIONS:

1. The reverse saturation current of a silicon p – n function diode at an operating temperature of 270C is 50 nA. Compute the dynamic forward and reverse resistances of the diode for applied voltages of 0.8 V and -0.4 V respectively 2. Find the value of D.C. resistance and A.C resistance of a Germanium junction diode at 250 C with reverse saturation current, Io = 25μA and at an applied voltage of 0.2V across the

diode VIVA QUESTIONS:

1. Define depletion region of a diode?

2. What is meant by transition & space charge capacitance of a diode?

3. Is the V-I relationship of a diode Linear or Exponential?

4. Define cut-in voltage of a diode and specify the values for Si and Ge diodes?

5. What are the applications of a p-n diode?

6. Draw the ideal characteristics of P-N junction diode?

7. What is the diode equation?

8. What is PIV?

9. What is the break down voltage?

10. What is the effect of temperature on PN junction diodes?

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 86 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 87 AIM: 10. ZENER DIODE CHARACTERISTICS

a) To observe and draw the static characteristics of a zener diode b) To find the voltage regulation of a given zener diode APPARATUS:

1. Zener diode - 1No.

2. Regulated Power Supply (0-30v) - 1No.

3. Voltmeter (0-20v) - 1No.

4. Ammeter (0-20mA) - 1No.

5. Resistor (1K ohm) - 1No.

6. Bread Board - 1No.

7. Connecting wires THEORY:

A zener diode is heavily doped p -n junction diode, specially made to operate in the break down region. A p -n junction diode normally does not conduct when reverse biased. But if the reverse bias is increased, at a particular voltage it starts conducting heavily. This voltage is called Break down Voltage. High current through the diode can permanently damage the device

To avoid high current, we connect a resistor in series with zener diode. Once the diode starts conducting it maintains almost constant voltage across the terminals whatever may be the current through it, i.e., it has very lo w dynamic resistance. It is used in voltage regulators.

CIRCUIT DIAGRAM A) STATIC CHARACTERISTICS :

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 88 b) REVERSE BIAS CHARACTERISTICS:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 89 OBSERVATIONS:

A) FORWARD BIAS characteristics :

S.NO Applied Voltage(V) Forward Voltage(V f) Forward Current(I f(mA)) DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 90 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 91

B) REVERSE BIAS Characteristics:

S.NO Applied Voltage(V) Reverse Voltage(V R) Reverse Current(I R(mA)) PROCEDURE:

A) Static characteristics:

1. Connections are made as per the circuit diagram.

2. The Regulated power supply voltage is increased in steps.

3. The Forward current (lf), and the forward voltage (Vf.) are observed and then noted in the tabular form.

4. A graph is plotted between Forward current (lf) on X-axis and the forward voltage (Vf) on Y-axis.

PRECAUTIONS:

1. The terminals of the zener diode should be properly identified 2. While determined the load regulation, load should not be immediately shorted.

3. Should be ensured that the applied voltages & currents do not exceed the ratings of the diode.

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 92 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 93 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 94 RESULT:

EXERCISE QUESTIONS:

1. A Zener voltage regulator circuit is to maintain constant voltage at 60 V, over a current range from 5 to 50 mA. The input supply voltage is 200 V. Determine the value of resistance R to be connected in the circuit, for voltage regulation from load current I L = 0 mA to I L max, the maximum possible value of IL. What is the value I L max?

VIVAQUESTIONS:

1. What type of temp coefficient does the zener diode have?

2. If the impurity concentration is increased, how the depletion width effected?

3. Does the dynamic impendence of a zener diode vary?

4. Explain briefly about avalanche and zener breakdowns?

5. Draw the zener equivalent circuit?

6. Differentiate between line regulation & load regulation?

7. In which region zener diode can be used as a regulator?

8. How the breakdown voltage of a particular diode can be controlled?

9. What type of temperature coefficient does the Avalanche breakdown has?

10. By what type of charge carriers the current flows in zener and avalanche breakdown diodes?

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 95 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 96 11. HALF -WAVE RECTIFIER

AIM:

To examine the input and output waveforms of half wave Rectifier APPARATUS:

S.No Name of the equipment Quantity 1 Digital Multimeter - 1No.

2 Transformer (6V-0-6V) - 1No.

3 Diode, 1N4007 - 1No.

4 Decade Resistance Box - 1No.

5 Breadboard - 1No.

6 CRO and CRO probes -- 7 Connecting wires -- THEORY:

In Half Wave Rectification, When AC supply is applied at the input, only Positive Half Cycle appears across the load whereas, the negative Half Cycle is suppressed. How this can be explained as follows:

During positive half -cycle of the input voltage, the diode D1 is in forward bias and conducts through the load resistor R L. Hence the current produces an output voltage across the load resistor RL, which has the same shape as the +ve half cycle of the input voltage.

During the negative half -cycle of the input voltage, the diode is reverse biased and there is no current through the circu it. i.e., the voltage across R L is zero. The net result is that only the +ve half cycle of the input voltage appears across the load. The average value of the half wave rectified o/p voltage is the value measured on dc voltmeter.

For practical circuits, transformer coupling is usually provided for two reasons.

1. The voltage can be stepped -up or stepped -down, as needed.

2. The ac source is electrically isolated from the rectifier. Thus preventing shock hazards in the secondary circuit.

The efficiency of the Half Wave Rectifier is 40.6% Theoretical calculations Vrms=Vm/2 Vm=2Vrms Vdc=Vm/П

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 97 CIRCUIT DIAGRAM:

MODEL WAVEFORMS:

PROCEDURE:

1. Connections are made as per the circuit diagram.

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. Find the theoretical of dc voltage by using the formula, Vdc=Vm/П Where, Vm=2Vrms, (Vrms=output ac voltage.) .

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 98 Tabular form: NO LOAD VOLTAGE VDC =V S.NO LOAD RESISTANCE O/P VOLTAGE RL (KILO -OHMS) VAC (V) VDC (V)

1 2 3 4 5

6 7 8 PRECAUTIONS:

1. The primary and secondary side of the transformer should be carefully identified 2. The polarities of all the diodes should be carefully identified.

3. While determining the % regulation, first Full load should be applied and then it should be decremented in steps.

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 99 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 100 RESULT:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 101 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 102 12. FULL -WAVE RECTIFIER

AIM: To Examine the input and output waveforms of Full Wave Rectifier APPARATUS:

S. No Name of the Equipment Quantity 1 Digital Multimeter - 1No.

2 Transformer (6V -0-6V) - 1No.

3 Diode, 1N4007 - 2No.

4 Decade Resistance Box - 1No.

5 Breadboard - 1No.

6 CRO and CRO probes -- 7 Connecting wires -- THEORY:

The circuit of a center -tapped full wave rectifier uses two diodes D1&D2. During Positive half cycle of secondary voltage (input voltage), the diode D1 is forward biased and D2is reverse biased. So the diode D1 conducts and current flows through load resistor RL.

During negative half cycle, diode D2 becomes forward biased and D1 reverse biased. Now, D2 conducts and current flows through the load resistor RL in the same direction. There is a continuous current flow through the load resistor R L, during both the half cycles and will get unidirectional current as show in the model graph. The difference between full wave and half wave rectification is that a full wave rectifier allows

unidirectional (one way) current to the load during the entire 360 degrees of the input signal and half-wave rectifier allows this only during one half cycle (180 degree).

THEORITICAL CALCULATIONS:

CIRCUIT DIAGRAM: Vrms = Vm/ √2 Vm =Vrms√2 Vdc=2Vm/П DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 103

Circuit Diagram:

MODEL WAVEFORMS:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 104 Tabular Form:

NO LOAD VOLTAGE VDC =VS.NO LOAD RESISTANCE O/P VOLTAGE RL (KILO -OHMS) VAC (V) VDC

(V) 1 2 3 4

5 6 7 8 PROCEDURE:

1. Connections are made as per the circuit diagram.

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

3. Measure the ac voltage at the input side of the rectifier.

4. Measure both ac and dc voltages at the output side the rectifier.

5. Find the theoretical value of the dc voltage by using the formula Vdc=2Vm/П PRECAUTIONS:

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

2. The polarities of all the diodes should be carefully identified.

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 105 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 106 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB

MRCET EAMCET CODE:MLRD mrcet.ac.in 107 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 108 RESULT:

DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 109 DEPARTMENT OF HUMANITIES AND SCIENCES PRINCIPLES OF ELECTR ICAL AND ELECTRONICS ENGINEERING LAB MRCET EAMCET CODE:MLRD mrcet.ac.in 110