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3 EDC Lab Manual

Sep 05, 2014

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Electronic Devices & CircuitsLaboratory Notes

By Mr.M.Siva Ganga PrasadAssociate professor

Dept. of ECE

KL University Guntur 2010-20111

Acknowledgements

We take this opportunity to thank all those who helped directly and indirectly in bringing this laboratory manual. We thank Dr.P.Siddaiah, Dean P&D, Dr. S.Lakshminarayana, HOD, Dept of ECE , co-authors prof N.Venkat Ram, K. Uday Kumar and all the faculty members, non teaching staff members who are involving in the preparation of laboratory manual.

AUTHOR

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Preface

Electronic Devices & Circuits (EDC) Laboratory practice is an elementary course taught to ECE, EEE and ECM branches of Engineering students at KL University. Basic concepts of different electronic devices like semi conductor diode, Bipolar junction Transistor(BJT), Junction Field Effect transistor(JFET), Uni-Junction Transistor(UJT), SCR etc.. are taught with their V-I characteristics in theory classes. In practical classes students are given hands on experience on what they have studied in lecture classes by verification and testing in laboratory. Students will be making simple mini projects based on the applications of various electronic devices which are used in day to day life. This will enable the students to get familiarized to use different devices and equipment in different circuits designing process which are useful in various communication fields. Our laboratory has facilities like CROs with high frequency range to test the response of various electronic circuits, Trainer boards and IC tester etc.. with all necessary accessories and attachments. Learning objective for each experiment is given in the beginning of the experiment in the manual. For each experiment , a list of review questions are included. Answering to these questions ensures learning of the process in terms of its application, using different techniques etc. Students are expected to answer all the review questions and to enter their observations in the manual itself.. Students will be working with each facility on rotation basis weekly twice. At the end of the semester, students are expected to familiarize completely for using all the facilities in the laboratory. Students can refer to appendix in the text book integrated electronics for additional information. Students are hereby informed ensure Safety First experiment next policy. We hope that this manual is admirably suited for students of second year first semester to have hands on experience in using various electronic devices.

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Table of ContentsExpt.No 1. 2. 3. 4. 5. Name of the experiment V-I Characteristics of PN junction Diode. V-I Characteristics of Zener junction Diode. Half wave rectifier without and with capacitor filter. Full wave rectifier without and with capacitor filter. Input & output Characteristics of Transistor in common Base configuration. Input & Output Characteristics of Transistor in common Emitter configuration. Input & Output Characteristics of Transistor in common Collector configuration. Transistor biasing circuit Characteristics of junction Field Effect Transistor Static Emitter Characteristics of Uni -junction Transistor V-I Characteristics of Silicon Controlled Rectifier. Transistor switching. Emitter Follower Page No 5 10 14 19 25

6.

30

7.

35

8. 9. 10. 11. 12. 13. 14

39 42 48 53 56

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EXPERIMENT NO:1

V-I Characteristics of PN junction Diode Learning Objectives: To learn about Properties of Diode 1N 4001 Cut-in voltage of Ge diode Static & dynamic resistance Of Ge diode Properties of Diode OA 79 Cut-in voltage of Si diode Static & dynamic resistance Of Si diode

Aim: 1. To plot V-I characteristics of Silicon and Germanium diodes. 2. Compare the forward characteristics of ge diode with that of Si diode. 3. Calculate the forward static and Dynamic resistance of the diodes at a particular operating point.

Apparatus Required: 1. Experimental board with Si and Ge diodes. 2. Regulated power supply. 3. Multi meters ( as volt meter and ammeter)

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Circuit Diagram: 1KmA

0-30 mA V 0-10 V

1N 4001

Circuit for Diode forward bias

1KA

0-500 A mA

V 0-20 V

1N 4001

Circuit for Diode reverse bias

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Procedure: 1. Find the type number of the diodes connected in the experimental board. 2. Trace the circuits and identify different components used in the circuit. Read the value of the resistor using the color code. 3. Connect the millimeter and voltmeter of suitable ranges, say 0-to-25mA for ammeter and 0-to-2v for voltmeter in forward bias and 0-100 micro A for ammeter and 0-to-30v for voltmeter in reverse bias. 4. Switch on the power supply. Increase the voltage range from 0 to 30v in proper steps. 5. Note the ammeter and voltmeter readings for each input voltage. Tabulate the observations Tabular forms: Forward Bias: Reverse Bias:

S.no

Vd volts

Id mA

S.no Vr volts

Ir A

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Model Graph:

Forward current Id

Reverse voltage Vr Cut-in voltage

Forward voltage Vd

Reverse current Ir

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Result: V-I characteristics of both Ge and Si diodes are verified.

Date:

Signature of Instructor

Review Questions 1. What is the cut-in voltage of Ge and Si diodes? 2. List out the important properties of PN junction diode. 3. What is static and dynamic resistance of diode? 4. What is reverse saturation current? 5. What are majority and minority charge carriers?

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EXPERIMENT NO:2

V-I Characteristics of Zener Diode Learning Objectives: To learn about Properties of Zener diode Break down voltage Voltage regulation Zener diode is never used as voltage regulator as the current of zener diode is less and there is a maximum dissipation across zener diode when the current is zero and this is generally as a voltage reference. Reverse bias characteristics of Zener diode Dynamic resistance of Zener diode

.

Aim: 1. To plot V-I characteristics of Zener diode under reverse biased condition. 2. Compare the forward characteristics with reverse characteristics. 3. Calculate the Dynamic resistance under reverse bias of Zener diode.

Apparatus Required: 1. Experimental board with Zener diode 0-30V, 1A dc. 2. Regulated power supply. 3. Multi meters ( as volt meter and ammeter)

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Circuit Diagram: 1K

A0-30 mA

V6Z8v 0-10 V

Zener Diode forward bias

1K

A0-30 mA

V6Z8v 0-20 V

Zener Diode reverse bias

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Procedure: 1. Connect the circuit as shown in figure with zener diode in forward bias. 2. Switch on the power supply 3. Set the voltage across the Zener diode at 0.0 V and observe the current. 4. Increase the Zener voltage in steps of 0.1 V upto 0.7 V and note down the readings of the milli ammeter for each voltage. 5. Connect the circuit for the Zener diode in reverse bias. 6. Set the voltage across the Zener diode at 0.0 V and observe the current. 7. Increase the Zener voltage in steps of 0.2 V until the diode goes into breakdown and note down the reading of the ammeter for each voltage. 8. After the diode goes into breakdown take two or three readings of current at the breakdown voltage. 9. Supply voltage must be greater than Zener break down voltage.

Tabular forms: Forward Bias: Reverse Bias:

S.no

Vz volts

Iz mA

S.no Vz volts

Iz mA

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Model Graph:

Result: V-I characteristics of Zener diode are verified.

Date: Review Questions

Signature of Instructor

1. What is Zener diode and at what range of voltage, it shows breakdown characteristics? 2. What is the difference between Zener and avalanche breakdowns which is greater of the two?. 3. Distinguish between an ordinary diode and Zener diode w.r.t their operational characteristics. 4. Mention the Practical applications of a Zener diode. 5. Is the Zener voltage temperature dependent, if yes how?13

EXPERIMENT NO:3

Half wave rectifier without and with capacitor filter Learning Objectives: To learn about Diode as a rectifier Ripple contents in Half wave rectifier Ripple factor of Half wave rectifier Efficiency of Half wave rectifier PIV of Half wave rectifier Generally a 0.1 F capacitor is shunted across the diodes in commercially available power supplies to reduce HF noise caused by the reverse recovery current being switched off when the current carries in the diodes are depleted.

Aim: 1.To find ripple factor of HWR 2. Verify the efficiency and percentage regulation of HWR without and with capacitor filter Apparatus Required: 1. Transformer 2. Diode -1N 4001. 3. Variable resistor 0-6K ohms. 4. Capacitor 100 F 5. Capacitor 0.1 F 6. Capacitor 100 F 7. Capacitor 1000 F 8. DC voltmeter 0-50V14

9. DC ammeter 0-50mA 10. AC voltmeter 0-50V 11. 10 v of D.C ,1 Amp power supply. Circuit Diagram: i)Half wave rectifier without filter

i i ) H ii) Half wave rectifier with capacitor filter

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Procedure: 1. Connect the rectifier circuit without capacitor filter. 2. Under open circuit condition, take Vdc, Vac . These are no load values. 3. Connect 1 K resistance at the load and take Idc, Vdc, Vac and tabulate. 4. Vary the load in steps of 1 K upto 6 K and tabulate the values . 5. Calculate ripple factor, % of regulation and efficiency of the rectifier for different loads. 6. Plot the graphs between Idc Vs ripple factor, Vdc Vs % of regulation. 7. Connect the filter capacitor and repeat the above steps. 8. The minimum current drawn should be 500 mA and go on decreasing 100 mA steps to study the load regulation and variation of ripple factor with load curre

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