circuit & devices lab manual

Circuit and devices lab manual B.KALAIMATHI AP/ECE

EC 6211 CIRCUITS AND DEVICES LABORATORY

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

Content beyond the syllabus

14. Half wave rectifier

15. Bridge wave rectifier


STUDY OF CRO An oscilloscope is a test instrument which allows us to look at the 'shape' of electrical

signals by displaying a graph of voltage against time on its screen. It is like a voltmeter with the valuable extra function of showing how the voltage varies with time. Gratitude with a 1cm grid enables us to take measurements of voltage and time from the screen. The graph, usually called the trace, is drawn by a beam of electrons striking the phosphor coating of the screen making it emit light, usually green or blue. This is similar to the way a television picture is produced. Oscilloscopes contain a vacuum tube with a cathode (negative electrode) at one end to emit electrons and an anode (positive electrode) to accelerate them so they move rapidly down the tube to the screen. This arrangement is called an electron gun. The tube also contains electrodes to deflect the electron beam up/down and left/right. The electrons are called cathode rays because they are emitted by the cathode and this gives the oscilloscope its full name of cathode ray oscilloscope or CRO.A dual trace oscilloscope can display two traces on the screen, allowing us to easily compare the input and output of an amplifier for example. It is well worth paying the modest extra cost to have this facility.

Figure 1: Front Panel of CRO

BASIC OPERATION:

Figure 2: Internal Blocks of CRO


Setting up an oscilloscope: Oscilloscopes are complex instruments with many controls and they require some care to

set up and use successfully. It is quite easy to 'lose' the trace off the screen if controls are set wrongly. There is some variation in the arrangement and labeling of the many controls. So, the following instructions may be adapted for this instrument. 1. Switch on the oscilloscope to warm up (it takes a minute or two). 2. Do not connect the input lead at this stage. 3. Set the AC/GND/DC switch (by the Y INPUT) to DC. 4. Set the SWP/X-Y switch to SWP (sweep). 5. Set Trigger Level to AUTO. 6. Set Trigger Source to INT (internal, the y input). 7. Set the Y AMPLIFIER to 5V/cm (a moderate value). 8. Set the TIMEBASE to 10ms/cm (a moderate speed). 9. Turn the time base VARIABLE control to 1 or CAL. 10. Adjust Y SHIFT (up/down) and X SHIFT (left/right) to give a trace across the middle of the screen, like the picture. 11. Adjust INTENSITY (brightness) and FOCUS to give a bright, sharp trace. The following type of trace is observed on CRO after setting up, when there is no input signal connected.

Figure 3: Absence of input signal

Connecting an oscilloscope:

The Y INPUT lead to an oscilloscope should be a co-axial lead and the figure 4 shows its construction. The central wire carries the signal and the screen is connected to earth (0V) to shield the signal from electrical interference (usually called noise). Most oscilloscopes have a BNC socket for the y input and the lead is connected with a push and twist action, to disconnect we need to twist and pull. Professionals use a specially designed lead and probes kit for best results with high frequency signals and when testing high resistance circuits, but this is not essential for simpler work at audio frequencies (up to 20 kHz).


Figure 5: Oscilloscope lead and probes kit

Obtaining a clear and stable trace: Once if we connect the oscilloscope to the circuit, it is necessary to adjust the controls to

obtain a clear and stable trace on the screen in order to test it. The Y AMPLIFIER (VOLTS/CM) control determines the height of the trace.

Choose a setting so the trace occupies at least half the screen height, but does not disappear off the screen.

The TIMEBASE (TIME/CM) control determines the rate at which the dot sweeps across the screen. Choose a setting so the trace shows at least one cycle of the signal across the screen. Note that a steady DC input signal gives a horizontal line trace for which the time base setting is not critical

The TRIGGER control is usually best left set to AUTO. The trace of an AC signal with the oscilloscope controls correctly set is as shown in Figure 6.

Figure 6 : Stable waveform

Measuring voltage and time period The trace on an oscilloscope screen is a graph of voltage against time. The shape of this graph is determined by the nature of the input signal. In addition to the properties labeled on the graph,

there is frequency which is the number of cycles per second. The diagram shows a sine wave but these properties apply to any signal with a constant shape


Figure 7: Properties of Trace

Amplitude is the maximum voltage reached by the signal. It is measured in volts. Peak voltage is another name for amplitude. Peak-peak voltage is twice the peak voltage (amplitude). When reading an oscilloscope

trace it is usual to measure peak-peak voltage. Time period is the time taken for the signal to complete one cycle.

It is measured in seconds (s), but time periods tend to be short so milliseconds (ms) and microseconds (μs) are often used. 1ms = 0.001s and 1μs = 0.000001s.

Frequency is the number of cycles per second. It is measured in hertz (Hz), but frequencies tend to be high so kilohertz (kHz) and megahertz (MHz) are often used. 1kHz = 1000Hz and 1MHz = 1000000Hz.

Frequency = 1/Time period

Time period = 1/Frequency A) Voltage: Voltage is shown on the vertical y-axis and the scale is determined by the Y AMPLIFIER (VOLTS/CM) control. Usually peak-peak voltage is measured because it can be read correctly even if the position of 0V is not known. The amplitude is half the peak-peak voltage.

Voltage = distance in cm × volts/cm B) Time period: Time is shown on the horizontal x-axis and the scale is determined by the TIMEBASE (TIME/CM) control. The time period (often just called period) is the time for one cycle of the signal. The frequency is the number of cycles per second, frequency = 1/time period.

Time = distance in cm × time/cm

STUDY OF FUNCTION GENERATOR


A function generator is a device that can produce various patterns of voltage at a variety of frequencies and amplitudes. It is used to test the response of circuits to common input signals. The electrical leads from the device are attached to the ground and signal input terminals of the device under test.

Figure 1: A typical low-cost function generator.

Features and controls : Most function generators allow the user to choose the shape of the output from a small number of options. Square wave - The signal goes directly from high to low voltage.

Figure 2: Square wave The duty cycle of a signal refers to the ratio of high voltage to low voltage time in a

square wave signal. Sine wave - The signal curves like a sinusoid from high to low voltage.

Figure 3: Sine Wave Triangle wave - The signal goes

from high to low voltage at a fixed rate.


Figure 4: Triangular Wave

The amplitude control on a function generator varies the voltage difference between the high and low voltage of the output signal. The direct current (DC) offset control on a function generator varies the average voltage of a signal relative to the ground. The frequency control of a function generator controls the rate at which output signal oscillates. On some function generators, the frequency control is a combination of different controls. One set of controls chooses the broad frequency range (order of magnitude) and the other selects the precise frequency. This allows the function generator to handle the enormous variation in frequency scale needed for signals. How to use a function generator After powering on the function generator, the output signal needs to be configured to the desired shape. Typically, this means connecting the signal and ground leads to an oscilloscope to check the controls. Adjust the function generator until the output signal is correct, then attach the signal and ground leads from the function generator to the input and ground of the device under test. For some applications, the negative lead of the function generator should attach to a negative input of the device, but usually attaching to ground is sufficient.

STUDY OF REGULATED POWER SUPPLY


There are many types of power supply. Most are designed to convert high voltage AC mains electricity to a suitable low voltage supply for electronic circuits and other devices. A power supply can by broken down into a series of blocks, each of which performs a particular function. For example a 5V regulated supply:

Figure 1: Block Diagram of Regulated power supply

Each of the blocks is described in more detail below: Transformer: Steps down high voltage AC mains to low voltage AC. Rectifier: Converts AC to DC, but the DC output is varying. Smoothing: Smooths the DC from varying greatly to a small ripple. Regulator: Eliminates ripple by setting DC output to a fixed voltage.

Dual Supplies: Some electronic circuits require a power supply with positive and negative outputs as well as zero volts (0V). This is called a 'dual supply' because it is like two ordinary supplies connected together as shown in the diagram. Dual supplies have three outputs, for example a ±9V supply has +9V, 0V and -9V outputs.

Figure 2: Dual Supply

CIRCUIT DIAGRAM:


FORWARD BIAS:

REVERSE BIAS:

Ex.No: CHARACTERISTICS OF PN DIODE


Date: AIM:

To study the PN junction diode characteristics under Forward & Reverse bias conditions.

APPARATUS REQUIRED:

S.No. Name of the Component Range Quantity Required

1 RPS (0-30)V 1

2 Ammeter (0–30)mA 1

(0–100)µA 1

3 Voltmeter (0–10)V 1

(0–1)V 1

4 Resistor 1K, 10K Each 1

5 Diode IN4007 1

TABULAR COLUMN:


FORWARD BIAS: REVERSE BIAS:

MODEL GRAPH

PROCEDURE:

S.No. VOLTAGE

(In Volts)

CURRENT

(In mA)

S..No. VOLTAGE

(In Volts)

CURRENT

(In A)


FORWARD BIAS:

1. Connect the circuit as per the diagram. 2. Vary the applied voltage V in steps of 0.1V. 3. Note down the corresponding Ammeter readings I. 4. Plot a graph between V & I

OBSERVATIONS

1. Find the d.c (static) resistance = V/I.

2. Find the a.c (dynamic) resistance r = V / I (r = V/I) = 12

12

IIVV

.

3. Find the forward voltage drop = [Hint: it is equal to 0.7 for Si and 0.3 for Ge]

REVERSE BIAS:

1. Connect the circuit as per the diagram.

2. Vary the applied voltage V in steps of 1.0V.

3. Note down the corresponding Ammeter readings I.

4. Plot a graph between V & I

5. Find the dynamic resistance r = V / I.

Specification for 1N4001: Silicon Diode

Peak Inverse Voltage: 50V

Idc = 1A.

Maximum forward voltage drop at 1 Amp is 1.1 volts

The maximum reverse current @50 volts is 5A


RESULT:

Forward and Reverse bias characteristics of the PN junction diode was studied and

Forward bias = ---------------------

Reverse bias = ----------------------.

Performance 2

Observation 2

Viva 2

Total 6


VIVA QESTIONS:-


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?

CIRCUIT DIAGRAM (ZENER DIODE)


FORWARD BIAS:

REVERSE BIAS:

Ex.No: CHARACTERISTICS OF ZENER DIODE


Date: AIM:

To study the Zener diode characteristics under Forward & Reverse bias conditions.

APPARATUS REQUIRED:

S.No. Name of the Component Range Quantity Required

1 RPS (0-30)V 1

2 Ammeter (0–30) mA 1


4 Zener diode FZ5.1 1

5 Resistor 1K 1

MODEL GRAPH


PROCEDURE:


FORWARD BIAS:

1. Connect the circuit as per the circuit diagram.

2. Vary the power supply in such a way that the readings are taken in steps of 0.1V in the

voltmeter till the needle of power supply shows 30V.

3. Note down the corresponding ammeter readings.

4. Plot the graph :V (vs) I.


REVERSE BIAS:

1. Connect the circuit as per the diagram.

2. Vary the power supply in such a way that the readings are taken in steps of 0.1V in the

voltmeter till the needle of power supply shows 30V.

3. Note down the corresponding Ammeter readings I.

4. Plot a graph between V & I


6. Find the reverse voltage Vr at Iz=20 mA.

RESULT:

Forward and Reverse bias characteristics of the zener diode was studied and

Forward bias dynamic resistance = ---------------------

Reverse bias dynamic resistance = ----------------------

The reverse voltage at Iz =20 mA determined from the reverse characteristics of the

Zener diode is --------------------------.


VIVAQUESTIONS:-

1. What type of temperature 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?

CIRCUIT DIAGRAM:


TABULAR COLUMN:

Input characteristics: VCE constant

VCE = VCE = VCE = VBE

(Volts)

IB

(A) VBE

(Volts) IB

(A) VBE

(Volts) IB

(A)

Ex.No:

CHARACTERISTICS OF CE CONFIGURATION OF BJT


Date: AIM:

To plot the transistor characteristic of common-emitter configuration and to find the h-parameters for the same.

EQUIPMENT REQUIRED:

S.No Name of the component Range Quantity

1 Power supply (0-30)V 2

2 Ammeter (0-10)mA,

(0-1)mA

Each 1

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

PROCEDURE:

i. Input characteristic:

1. Rig up the circuit as per the circuit diagram. 2. Set VCE = 5V (say), vary VBE insteps of 0.1V till the power supply VBB shows

20V and note down the corresponding IB. Repeat the above procedure for 10V, 15V etc.,

3. Plot the graph: VBE vs IB for a constant VCE. 4. Find the h-parameters: a. hrc : reverse voltage gain

b. hfc: input impedance


MODEL GRAPH:

Input Characteristics

TABULATION:

Output characteristics: IB constant

IB = IB = IB = VCE

(Volts)

IC (mA)

VCE

(Volts) IC (mA)

VCE

(Volts) IC (mA)


ii. Output characteristic:

1. Rig up the circuit as per the circuit diagram. 2. Set IB = 20A (say), vary VCE insteps of 1V and note down the corresponding

IC. Repeat the above procedure for 80A, 200A, 600A etc., 3. Plot the graph: VCE Vs IC for a constant IB. 4. Find the h-parameters: a. hoc : output admittance

b. hfc: forward current gain

MODEL GRAPH:


Output Characteristics


Result:

Thus the input and output characteristics of BJT under CE configuration are obtained.

Parameters Practical readings

hfc

hic

hrc

hoc

Performance 2

Observation 2

Viva 2

Total 6


VIVA QUESTIONS:


1. What is the range of for the transistor?

2. What are the input and output impedances of CE configuration?

3. Identify various regions in the output characteristics?

4. what is the relation between and

5. Define current gain in CE configuration?

6. Why CE configuration is preferred for amplification?

7. What is the phase relation between input and output?

8. Draw diagram of CE configuration for PNP transistor?

CIRCUIT DIAGRAM:


TABULAR COLUMN:

Input characteristics: VCB constant

VCB = VCB = VCB = VEB

(Volts)

IE (mA)

VEB

(Volts) IE (mA)

VEB

(Volts) IE (mA)


Ex.No:

CHARACTERISTICS OF CB CONFIGURATION Date:

AIM:

To plot the transistor characteristic of common-base configuration and to find the h-parameters for the same.

APPARATUS REQUIRED:


1 Power supply (0-30) V 2

2 Ammeter (0-20)mA, 2

3 Voltmeter (0-20)V 2

PROCEDURE:

i. Input characteristic:

1. Rig up the circuit as per the circuit diagram. 2. Set VCB = 5V (say), vary VEB in a regular steps 0.1V till the power supply VEE

shows 20V and note down the corresponding IE. Repeat the above procedure for 10V, 15V etc.,

3. Plot the graph: VEB Vs IE for a constant VCB. 4. Find the h-parameters: a. hrb : reverse voltage gain

b. hfb: input impedance

ii. Output characteristic:

5. Rig up the circuit as per the circuit diagram. 6. Set IE = 1mA (say), vary VCB insteps of 1V and note down the corresponding

IC. Repeat the above procedure for 3mA, 6mA, 10mA etc., 7. Plot the graph: VCB Vs IC for a constant IE. 8. Find the h-parameters: a. hob : output admittance

b. hfb: forward current gain

MODEL GRAPH:


Input characteristics

Output characteristics: IE constant

VE = VE = VE = VCB

(Volts)

IC (mA)

VCB

(Volts) IC (mA)

VCB

(Volts) IC (mA)


MODEL GRAPH:


RESULT:

Thus the input and output characteristics of BJT under CB configuration are obtained.


hfb

hib

hrb

hob

CIRCUIT DIAGRAM:

Performance 2

Observation 2

Viva 2

Total 6


PIN DIAGRAM:

BOTTOM VIEW OF BFW10:

SPECIFICATION:

Voltage : 30V, IDSS > 8mA.

Ex.No:


CHARACTERISTICS OF JUNCTION FIELD EFFECT TRANSISTOR

Date:

AIM:

To Plot the characteristics of given FET & determine rd, gm, , IDSS,VP.

APPARATUS REQUIRED:

S.No. Name of the component Range Quantity

1 RPS (0-30)V 2

2 Ammeter (0–30)mA 1


4 FET BFW10

1

5 Resistor 1k,68K One Each

6 Bread Board 1

PROCEDURE:

DRAIN CHARACTERISTICS:


2. Set the gate voltage VGS = 0V.

3. Vary VDS in steps of 1 V & note down the corresponding ID.

4. Repeat the same procedure for VGS = -1V.

5. Plot the graph VDS Vs ID for constant VGS.

MODEL GRAPH:



TRANSFER CHARACTERISTICS:

OBSERVATIONS

1. d.c (static) drain resistance, rD = VDS/ID.

2. a.c (dynamic) drain resistance, rd = VDS/ID.


3. Open source impedance, YOS = 1/ rd.



2. Set the drain voltage VDS = 5 V.

3. Vary the gate voltage VGS in steps of 1V & note down the corresponding ID.

4. Repeat the same procedure for VDS = 10V.

5. Plot the graph VGS Vs ID for constant VDS.

FET PARAMETER CALCULATION:

Drain Resistancd rd = GSD

DS VI

V

Transconductance gm = DSGS

D VVI

Amplification factor μ=rd . gm

TABULAR COLUMN:



VGS = 0V VGS = -1V

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


VDS =5volts VDS = 10volts

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


RESULT:

Thus the Drain & Transfer characteristics of given FET is Plotted.

Rd =

gm =

=

IDSS =

Pinch off voltage VP =

Performance 2

Observation 2

Viva 2

Total 6


VIVA QUESTIONS:

1. What are the advantages of FET?

2. Different between FET and BJT?


3. Explain different regions of V-I characteristics of FET?

4. What are the applications of FET?

5. What are the types of FET?

6. Draw the symbol of FET.

7. What are the disadvantages of FET?

8. What are the parameters of FET?

SCR CIRCUIT DIAGRAM:


MODEL GRAPH:

TABULAR COLUMN:

VAK (volts) IA (mA)

Ex.No: CHARACTERISTICS OF SCR

IA(mA)

Negative resistance region

VBO VAK (VOLTS)

IH

IL


Date:

AIM: To find the latching and holding current for a given SCR.

APPARATUS REQUIRED:


1.

2.

3.

4.

5.

6.

Power supply

SCR

Resistor

Ammeter

Voltmeter

Bread Board

(0-30)V

1KΩ

(0-30)mA

(0-30)V

-

2

1

1

2

1

1

PROCEDURE FOR SCR:

1. Rig up the circuit as per the circuit diagram. 2. Set gate current IG

equal to firing current, vary anode to cathode voltage VAK in steps of 0.5V and note down the corresponding anode current IA.

3. VBO is the point where the SCR voltage (VAK) suddenly drops and sudden increase anode current IA.

4. Note down the current at that point called latching current. 5. Increase the VAK insteps of 1V till its maximum. 6. Open the gate terminal and decrease the anode voltage VAK. 7. Holding current is the current below, which the deflection in both voltmeter (VAK)

and an ammeter (IA) suddenly reduces to zero. 8. Holding current is the minimum current that a SCR can maintain its condition.

Holding current always less than latching current.


RESULT:

Thus the characteristics of SCR verified and graph were drawn.


Peak voltage

Valley voltage

Performance 2

Observation 2

Viva 2

Total 6


Clipper Circuit Diagram


Ex.No: CLIPPER AND CLAMPER

Date: AIM:

To design and construct the clipper, clamper, integrator, differentiator circuits and draw

the waveforms.

APPARATUS REQUIRED:

Procedure:

1.Ring up the circuit as per the circuit diagram.

2. Set input signal voltage (say 5V, 1 k Hz) using signal generator.

3. Observe the output waveform using CRO (DC – mode).

4. Sketch the observed waveform on the graph sheet.

S.No APPARATUS REQUIRED RANGE QUANTITY

1 Resistors 1KΩ 1

2 Diode 1N4007 1

3 Power supply 0-30V 1

4 Capacitors 0.1 µF 1

5 CRO (0 -30)MHz 1

6 Bread board - 1

7 CRO Probes - 3

8. Signal generator (0-2)MHz 1

9. Bread Board –


Clamper circuit diagram


RESULT:

Thus Clipper and Clamper circuits were constructed and their output was obtained.

Circuit diagram:

Without Filter:-

Performance 2

Observation 2

Viva 2

Total 6


With Filter:-

Ex.No: FULL WAVE RECTIFIER


Date:

Aim:

To construct a full wave rectifier and to measure DC voltage under load and to calculate the ripple factor.

Apparatus Required:

S.No. Name of the Component / Apparatus Specification / Range Quantity

1 Transformer (9 – 0 – 9 ) V 2 2 Diode 1N4007 2

3 Resistor 1kΩ 2

4 Capacitor 47µF 1 5 CRO (0-30)MHz 1 6 Bread Board - 1 7 Connecting wires -

Model Graph:


Procedure:

Connections are given as per the circuit diagram without filter.


Note the amplitude and time period of the input signal at the secondary winding of the

transformer and rectified output.

Repeat the same steps with the filter and measure Vdc.

Calculate the ripple factor.

Draw the graph for voltage versus time.

as no such means is provided.

Tabulation:


S.No Condition Input Signal Output Signal

Amplitude Frequency Amplitude Frequency

1 Without Filter

2 With Filter


RESULT:

Thus the full wave rectifier was constructed and its input and output waveforms are drawn.

Theoretical Practical DC Voltage

Ripple Factor

Performance 2

Observation 2

Viva 2

Total 6


VIVA QUESTIONS:-

1. Define regulation of the full wave rectifier?

2. Define peak inverse voltage (PIV)? And write its value for Full-wave rectifier?


3. If one of the diode is changed in its polarities what wave form would you get?

4. Does the process of rectification alter the frequency of the waveform?

5. What is ripple factor of the Full-wave rectifier?

6. What is the necessity of the transformer in the rectifier circuit?

7. What are the applications of a rectifier?

8. What is ment by ripple and define Ripple factor?

9. Explain how capacitor helps to improve the ripple factor?

10. Can a rectifier made in INDIA (V=230v, f=50Hz) be used in USA (V=110v, f=60Hz)?

Circuit diagram:


Thevenin’s Voltage Experiment set up:

Thevenin’s Resistance Experiment set up:

Thevenin’s circuit:

Ex.No: VERIFICATION OF THEVENIN AND NORTON THEOREMS

Date:

AIM:

To verify the Thevenin and Norton theorem for the given circuit diagram


APPARATUS REQUIRED:



2 Ammeter (0-10)V 1

3 Power supply (0 – 30)V 1

4 Resister 1KΩ 4

500Ω,50Ω Each 1

PROCEDURE:

THEVENIN THEOREM

1. Connect the circuit as per the circuit diagram. 2. Measure the voltage across the load using voltmeter.

To find Thevenin’s voltage:

1. Connect the circuit as per the circuit diagram. 2. Remove the load resistance and measure the open circuited voltage across the output

terminal using voltmeter (Vth).

To find thevenin’s resistance:

1. Connect the circuit as per the circuit diagram. 2. Replace the supply by its internal resistance and open circuit the load. 3. Using multimeter in resistance mode measure the resistance across the output

terminal (Rth).

TABULAR COLUMN: THEVENIN THEOREM

Voltage (volts) Open circuit

voltage (volts)

Thevenin’s

resistance ()

Voltage (fig 2d)

(volts)


Circuit Diagram:

Norton’s Voltage Experiment Set up:

Thevenin’s circuit:

1. Connect the power supply (Vth) & resistance (Rth) in series. 2. Connect the load resistance (1K). 3. Switch on the power supply & measure the voltage drop across load resistance using

voltmeter. 4. Voltage measured should be equal to the voltage measured.

NORTON THEOREM


1. Connect the circuit as per the circuit diagram. 2. Measure the voltage across the load using voltmeter.

To find Norton’s voltage:

1. Connect the circuit as per the circuit diagram. 2. Short-circuit the load resistance and measure the short-circuited current using

ammeter (INO).

To find Norton’s resistance:

1. Connect the circuit as per the circuit diagram. 2. Replace the supply by its internal resistance and open circuit the load. 3. Using multimeter in resistance mode measure the resistance across the output

terminal (Rth).

To find Norton’s circuit:

1. Connect the current source (INOR) and Rth in parallel. 2. Connect the load resistance (1K). 3. Switch on the current source & measure the voltage drop across load resistance using

voltmeter. 4. Voltage measured should be equal to the voltage measured.

Norton’s Resistance Experiment Set up:

Norton’s Circuit:


TABULAR COLUMN:

I1(mA) I2(mA) I1 + I2 (mA) I (mA)


RESULT:

Thus the Thevenin and Notron theorem was verified.

CIRCUIT DIAGRAM:

Performance 2

Observation 2

Viva 2

Total 6

Circuit diagram for verification of KCL


Fig.1a Circuit diagram for verification of KCL

Fig.1b Circuit diagram for verification of KVL

Ex.No: VERIFICATION OF KIRCHOFF’S CURRENT AND VOLTAGE LAWS

Date:

AIM:

Circuit diagram for verification of KVL


To verify Kirchhoff’s Current law (KCL) and Kirchhoff’s Voltage law (KVL).

APPARATUS REQUIRED:


Required

1 Resistor 270Ω, 330Ω, 3560Ω 1 each

2 Ammeter (0-10)mA 3

3 Regulated power supply(RPS) (0-30)V 1


5 Bread board - 1

PROCEDURE (KCL):

1. Connect the circuit as shown in Fig (1). 2. Switch ON the Regulated Power Supply (RPS) and set the RPS to a particular value of

voltage say 5V. 3. Record the readings of three ammeters namely I1,I2,I3 with proper sign by taking current

entering the node as positive and leaving the node as negative in the observation Table(1).

4. Add I2 and I3 and verify whether the added value is equal to I1. (As per KCL, I1=I2+I3). 5. Increase the RPS settings in steps of 5V up to a maximum of 25V. 6. Repeat the steps 3 to 5 by incrementing the RPS settings in terms of 5V.

TABULAR COLUMN (KCL)

SL.NO RPS VOLTAGE (Volts) I1 (mA) I2 (mA) I3 (mA) I1= I2+I3(mA)

1 5


2 10

3 15

4 20

5 25

TABULAR COLUMN (KVL)

SL.NO RPS Voltage (Volts) V1(Volts) V2 (Volts) V3 (Volts)

V=V1+ V2 + V3 (Volts)

1 5

2 10

3 15

4 20

5 25

PROCEDURE (KVL):

1. Connect the circuit as shown in Fig (2). 2. Switch ON the Regulated Power Supply (RPS) and set the RPS to a particular value of

voltage (V) say 5V.


3. Record the readings of two voltmeters namely V1, V2 and RPS Voltage in the observation table (2).

4. Add V1 and V2 and verify whether the added value is equal to V. (as per KVL V = V1+V2).

5. Increase the RPS settings in steps of 5V up to a maximum of 25V. Repeat the steps 2 to 5 for each value of RPS setting.

RESULT

Thus the verification of Kirchhoff’s current law and Kirchhoff’s voltage law is done.

Performance 2

Observation 2

Viva 2

Total 6


TABULAR COLUMN:

I1(mA) I2(mA) I1 + I2 (mA) I (mA)


Ex.No:

VERIFICATION OF SUPERPOSITION THEOREM Date:

AIM:

To verify the superposition theorem

APPARATUS REQUIRED:




3 Resister 10KΩ, 50Ω 3,1

4 Bread board 1

PROCEDURE:

1. Connect the circuit as per the circuit diagram [fig4a] 2. Switch on the DC power supplies (10V & 5V) and note down the corresponding

ammeter readings (say I A). 3. Replace the second power supply by its internal resistance [fig4b]. 4. Switch on the power supply (10V) and note down the corresponding ammeter reading

(say I1). 5. Connect back the second power supply (5V) and replace the first power supply by its

internal resistance [fig4c]. 6. Switch on the power supply (5V) and note down the corresponding ammeter reading

(say I2). 7. Verify the following condition:

I = I1 + I2


RESULT:

Thus the superposition theorem was verified.

CIRCUIT DIAGRAM:

Performance 2

Observation 2

Viva 2

Total 6


TABULAR COLUMN:

Case (A): RL = RN = 1 K

XC ( ) V (Volts) I (mA) P = V I

Ex.No: VERIFICATION OF MAXIMUM POWER TRANSFER AND


RECIPROCITY THEOREMS Date:

AIM:

To verify the maximum power transfer theorem for the given circuit diagram

APPARATUS REQUIRED:


1 Signal generator (0-1)MHz 1



PROCEDURE:

1. Connect the circuit as per the circuit diagram. 2. Set the network DRB and DIB at some random value (say 1K & 1 mH). 3. Set the load DRB to the value equal to network DRB (1K) and vary the DCB of the

load in regular steps. 4. Note down the corresponding voltmeter & ammeter readings. 5. Plot the graph: Power Vs capacitance reactance. 6. Now set the load reactance equal to the network reactance. 7. Vary the DRB of the load in regular steps. 8. Note down the corresponding voltmeter & ammeter readings. 9. Plot the graph: Power Vs load resistance. 10. Compare the peak power of both the cases.

Case (B): XL = -XC = 1 mH/1mF


RL () V (Volts) I (mA) P = V I

MODEL GRAPHS:

Fig 4b Fig 4c

Pwatt

Pwatt

Capaciatnce (f) Resistance (


RESULT:

Thus the maximum power transfer theorem and reciprocity theorem were verified.

CIRCUIT DIAGRAM:

Performance 2

Observation 2

Viva 2

Total 6


Series resonance

MODEL GRAPH:

Ex.No: FREQUENCY RESPONSES OF SERIES AND PARALLEL Date: RESONANCE CIRCUITS


AIM:

To design a RLC series and parallel resonance circuit and to obtain the frequency response.

APPARATUS REQUIRED:


1 Signal generator (0-1)MHz 1



4 Resistor 1KΩ 2

5 Capacitor 1µF 1

6 Inductor 1mH 1

7 Bread board 1

PROCEDURE (Series Resonance):

1. Rig up the circuit as per the circuit diagram. 2. Set input voltage, VI = 5V using signal generator and vary the frequency from (0-1M)

Hz in a regular steps. 3. Note down the corresponding output voltage and current. 4. Plot the following graph:

a. Current Vs frequencies b. Voltage Vs frequencies c.

To measure the resonance frequency:

1. Plot the graph: Current Vs frequencies.

Parallel Resonance:


MODEL GRAPH:

1. Draw a horizontal line, which intersects the curve at 2

1times the maximum current

reading.


2. Lower intersected point and upper intersected point are respectively called lower cut-off frequency and upper cut-off frequency on frequency axis.

Bandwidth, BW = f2 – f1

Selectivity = Bandwidth/f0 = (f2 – f1)/ f0

PROCEDURE (Parallel Resonance):

1. Rig up the circuit as per the circuit diagram. 2. Set input voltage, VI = 5V using signal generator and vary the frequency from (0-1M)

Hz in a regular steps. 3. Note down the corresponding output voltage and current.

4. Plot the graph: Normalized impedance

0ZZ

Vs frequencies

To measure the resonance frequency:

1. Plot the graph: Normalized impedance

0ZZ

Vs frequencies

2. Draw a horizontal line, which intersects the curve at 2

1times the maximum current

reading.

3. Lower intersected point and upper intersected point are respectively called lower cut-off frequency and upper cut-off frequency on frequency axis.

Quality factor:

Q0 = ReactanceResistnace =

LωR

0

= RLC


Bandwidth & selectivity:


In parallel resonance circuit, the specified points are the one at which normalized impedance

falls to 2

1of its value at resonance.

Bandwidth, BW = f2 – f1

Selectivity = Bandwidth/f0 =(f2 – f1)/ f0

RESULT:

Thus the parallel and series RLC circuit was designed and the frequency response curves were drawn.

CIRCUIT DIAGRAM:

RC circuit diagram:

Performance 2

Observation 2

Viva 2

Total 6


RL circuit diagram:

Ex.No: TRANSIENT ANALYSIS OF RL AND RC CIRCUITS


Date:

AIM:

To design a RL and RC circuit and to obtain the Steady state response.

APPARATUS REQUIRED:





4 Resistor 12KΩ 1

5 Capacitor 1000µF 1

6 Inductor 1mH 1

7 Bread board 1

PROCEDURE (Series Resonance):


2. Switch over the contact to position 1.

3. Switch on the power supply and stopwatch simultaneously.

4. Take the ammeter and voltmeter reading in a regular time interval.

5. Switch over the contact to position 2 and simultaneously reverse the polarity of ammeter.

6. Note down the reading from the ammeter and voltmeter at regular time intervals.

7. Plot the graph: voltage vs time (charging and discharging)

Current vs time (charging and discharging)

Tabulation:

Voltage(volts) Time( sec)


MODEL GRAPH:

Charging graph:


Discharging graph:


RESULT:

Thus the RL & RC circuit was designed and the Steady state response curves were drawn.

Performance 2

Observation 2

Viva 2

Total 6


CONTENT BEYOND THE SYLLABUS

CIRCUIT DIAGRAM:

WITHOUT FILTER:


WITH FILTER:

Ex.No: HALF WAVE RECTIFIER


Date:

Aim:

To construct a half wave rectifier and to measure DC voltage under load and to calculate the ripple factor.

Apparatus Required:



3 Resistor 1kΩ 2


Model Graph:


Tabulation:



1 Without Filter

2 With Filter

Procedure:









RESULT:

Thus the half wave rectifier was constructed and its input and output waveforms are drawn.


Ripple Factor

Performance 2

Observation 2

Viva 2

Total 6


Viva Questions and answers:


1. In a half-wave rectifier, the load current flows for only the

…………………………………….. of the input signal.

2. A half-wave rectifier is equivalent to a ……………………… circuit.

3. The output of a half-wave rectifier is suitable for running …........... motors.

4. The DC output polarity from a half-wave rectifier can be reversed by reversing the

………………….…

5. In a half wave rectifier if a resistance equal to load resistance is connected in parallel with

the diode then the circuit will ………………………………………….

6. The efficiency and ripple factor of a half-wave rectifier is ………………… and

………………..

7. The main job of a voltage regulator is to provide a nearly …….…………… output voltage.

8. In a Zener diode voltage regulator, the diode regulates so long as it is kept in

………………….. bias condition.

9. In Zener diode regulator, the maximum load current which can be supplied to load resistor is

limited in between ………………….. and ……………………….

10. The percentage voltage regulation of voltage supply providing 100 V unloaded and 95 V at

full load is …………………………………

CIRCUIT DIAGRAM: WITHOUT FILTER:


WITH FILTER:

Ex.No: BRIDGE WAVE RECTIFIER


Date:

Aim:

To construct a bridge wave rectifier and to measure DC voltage under load and to calculate the ripple factor.

Apparatus Required:



3 Resistor 1kΩ 2


Model Graph:


Tabulation:



1 Without Filter

2 With Filter

Procedure:









RESULT:

Thus the bridge wave rectifier was constructed and its input and output waveforms are drawn.


Ripple Factor

Performance 2

Observation 2

Viva 2

Total 6


VIVAQUESTIONS:-

1. What is the PIV of Bridge rectifier?

2. What is the efficiency of Bridge rectifier?


3. What are the advantages of Bridge rectifier?

4. What is the difference between the Bridge rectifier and fullwaverectifier?

5. What is the o/p frequency of Bridge Rectifier?

6. What is the disadvantage of Bridge Rectifier?

7. What is the maximum secondary voltage of a transformer?

8. What are the different types of the filters?

9. What is the difference between the Bridge rectifier and half wave Rectifier?

10. What is the maximum DC power delivered to the load?

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