# Electronics Lab Manual

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```					ELECTRONICS LAB MANUAL
CONTENTS

Expt.No   Date   Name of the Experiment   Page No.   marks   Remarks
LIST OF EXPERIMENTS

1. Measurement of voltage, frequency and phase angle using CRO

2. Characteristics of PN Junction Diode and Zener Diode

3. Single Phase Half Wave Rectifier (With & Without Filter)

4. Single Phase Full Wave Rectifier (With & Without Filter)

5. Transfer Characteristics- CE configuration.

6. Single Stage RC coupled Amplifier

7. Emitter Follower

8. OP-AMP APPLICATIONS – Inverting, Non Inverting & Summer

9. OP-AMP APPLICATIONS - Integrator and Differentiator

10.OP-AMP APPLICATIONS - Wein bridge Oscillator

11.OP-AMP APPLICATIONS - Rectangular and Triangular Wave
Generator

12.RTD, Thermister Characteristics
EX.NO:
DATE:

MEASUREMENT OF VOLTAGE, FREQUENCY AND PHASE ANGLE USING
CRO

Aim:

To measure the amplitude and phase difference using Lissaujous pattern on CRO.
Apparatus Required;

S.NO              APPARATUS          TYPE              RANGE              QTY
1                 CRO                                                     1
3                 Resistors                            1kohm              1
4                 AFO                                                     2

Theory:
The CRO is a versatile testing and measuring instrument that can display voltage
information as a function of time. It can be used for qualitative and quantitative
measurement of voltage, current, phase and frequency. It is a vaccum tube in which
electron gun, consisting of the cathode grid and two anode, produces an electron beam
that is directed on fluorescent screen.
Formula:

Frequency measurement:
Fy/Fx = Number of loops in X-axis/Number of loops in Y-axis.
Here Fy = Unknown frequency
Here Fx= Known frequency
Phase Measurement:
θ = tan-1 (2 Π f RC)
Tabulation
Wave Form No of               Time/div Volt/div  Time     Frequency Amplitude
divisions         (ms)     (v)       Period (Hz)          (V)
Xaxis Y                              (ms)
axis
Study of wave forms:
1. Give the AFO output to CRO through probe.
2. Observe the waveform in the CRO, measure the amplitude and time period
of one cycle.
3. Repeat the step 2 for sine, square and triangular wave inputs.
Measurement of phase angle:
1.     Give the circuit connection as per the diagram. Apply sinewave input .
2.     Set the resistor and capacitor of 1 kilo ohms and 0.01 microfarad.
3.     Note the diameter of major and minor access.
4.     Note the phase angle theoretically and practically and compare them.
Measurement of frequency:
1.     Connect the two AFO’s to 2 CRO’s channels.
2.     Set the known frequency in one AFO and then tune the other AFO
frequency
to get the Lissaujous pattern .
Inference:
Result:
EXP.NO:

DATE      :

CHARACTERISTICS OF PN JUNCTION DIODE AND ZENER DIODE.

AIM:

To study the forward and reverse bias characteristics of PN junction diode and
ZENER diode.

APPARATUS REQUIRED:

1. Diode                 Ge    0A79                   1

2. Zener diode           (Vz =9V)                     1

3. Resistor              (270 ohm)                    1

4. RPS                   (0-30V) (0-5V)               1

5. Voltmeter             (DC) (0-30V)                 each one.
“ ( 0-15V)
“   (0-5V)

6.   Ammeter              (DC) (0-50mA)              each one
“ (0-50uA)

8. Wires                                                 10

Theory:

A PN Junction Diode consists of a PN junction, formed either by Ge or Si
crystal.The diode has two terminals namely anode and cathode.
The Zener diode is a silicon PN junction device, which is quite different from a
rectifier diode in the sense that it is operated in the reverse breakdown region. The break
down region is carefully controlled by the amount of doping.
Here we are going to study the VI characteristics of the PN junction diode and the
Zener Diode.
Specifications:
a) PN junction diode:
LF(Max)=50mA..
VF(Max)=0.3V
LR(Max)=100µA.
VR(Max)=15V
b) Zener Diode
VZ=9V
IF(Max)=80mA
VR(Max)=9V
Max power=1 watt

Circuit Diagram

Forward Bias
220Ω
+   -

+
(0-3V)
- (0-3V)

Reverse Bias
Procedure :
1. Rig up the circuit as shown in figure.
2. The power supply is switched on and the supply voltage is varied in steps and
Corresponding and current reading are noted.
3. A graph between applied (forward & reverse) voltage and diode current is
drawn.
4. From the graph threshold voltage is calculated.

Model graph:

(b). ZENER DIODE

Forward Bias
220Ω
+       -

+
(0-3V)
- (0-3V)
Reverse Bias

Procedure :
1.Rig up the circuit as shown in figure.
2.The power supply is switched on and the supply voltage is varied in steps and
corresponding and current reading are noted.
3.A graph between applied (forward & reverse) voltage and diode current is
drawn.
4.From the graph threshold voltage is calculated.

Model Graph
Result
EX.NO:
DATE:
SINGLE PHASE HALF WAVE RECTIFIER
AIM
To study the single phase half wave and rectifier and to test the performance
with & without filter.

APPARATUS REQUIRED

S.NO      APPARATUS                  RANGE             TYPE              QTY
01        Diode                      -                 IN 4007           2
02        Resistor                   1KΩ               -                 1
03        Capacitor                  1000µF            -                 1
04        Transformer                6-0-6 V           -                 1
05        CRO                        -                 -                 1

THEORY:

A rectifier is a circuit which uses one or more diodes to convert ac voltage to dc
voltage.

Half wave rectifier:
The circuit produces o/p during only one half cycle (i.e.) it allows the current to flow
through the load during +ve half cycle only.

CIRCUIT DIAGRAM: HALF WAVE RECTIFIER
MODEL GRAPH:

PROCEDURE:

01. Connections are given as per the circuit diagram
02. Switch ON the power supply. The input readings are noted from the CRO
and tabulated.
03. The readings of half wave rectifier are noted from the CRO and tabulated.
04. Graph is plotted taking voltage along the Y the axis and time along the X
axis

TABULATION:
Description No of        No of div in   Time/div    Volt/div   Amplitu   Time
div in x     y axis                                de(V)     period(ms)
axis
Input

Output

1.With filter

2.Without
filter

QUESTIONS:

1.   What is the use of filter?
2.   Name the building block of power supply.
3.   What is the use of bleeder resistor?
4.   Define regulation.
5.   Write the advantage of CLC filter.

INFERENCE:

RESULT:
EX.NO:
DATE:
SINGLE PHASE FULL WAVE RECTIFIER
AIM
To study the single phase full wave rectifier and to test the performance with &
without filter.

APPARATUS REQUIRED

S.NO      APPARATUS                  RANGE              TYPE              QTY
01        Diode                      -                  IN 4007           2
02        Resistor                   1KΩ                -                 1
03        Capacitor                  1000µF             -                 1
04        Transformer                6-0-6 V            -                 1
05        CRO                        -                  -                 1

THEORY:

A rectifier is a circuit which uses one or more diodes to convert ac voltage to dc
voltage.

Full wave rectifier
The circuit produces o/p during both the cycle of i/p. so it is called full wave rectifier

CIRCUIT DIAGRAM: FULL WAVE RECTIFIER
MODEL GRAPH:

PROCEDURE:

1.    Connections are given as per the circuit diagram
2.    Switch ON the power supply. The input readings are noted from the CRO
and tabulated.
3.    The readings of full wave rectifier are noted from the CRO and tabulated
4.     Graph is plotted taking voltage along the Y the axis and time along the X
axis.

TABULATION:
Description No of            No of div in    Time/div     Volt/div   Amplitu    Time
div in x         y axis                                  de(V)      period(ms)
axis

Input

Output

1.With filter

2.Without
filter

QUESTIONS:
6. What is the use of filter?
7. Name the building block of power supply.
8. What is the use of bleeder resistor?
9. Define regulation.
10. Write the advantage of CLC filter.

INFERENCE:

RESULT:
EX. NO.:
DATE :
CHARACTERISTICS OF BJT UNDER
CE CONFIGURATION
AIM: To study the input and output characteristics of common emitter transistor
configuration.

APPARATUS REQUIRED:

Apparatus             Range                  Type                    Quantity
Transistor                   BC147                                          1
Power supply                 0-5, 0-15 V                                    1 each
Voltmeter                    0-5, 0-15 V            MC                      1 each
Ammeter                      0-25mA, 0-250µA        MC                      1 each
Resistor                     560 ohms, ¼ wats                               1

THEORY:
Transistor has a very important property that it raises the strength of the weak
signal. This property is called amplification. A transistor consists of two PN junctions.
Sandwiching either P type or N type semiconductor layers between a pair of opposite
types forms the junctions. The transistor is having three terminals namely emitter, base,
collector.
SYMBOL:
C
B

B           BC147                                          E                C          C

E
CIRCUIT DIAGRAM:                                         - (0-25) mA +

A

C

560           + (0-250)µA -
B
A
+
E                     (0-15)V V
-
RPS                                           +
(0-30)V                        (0-5) V                                                           RPS
V
-`                                                                                     (0-30)V
-

PROCEDURE:
INPUT CHARACTERISTICS:
1.   Connections are given as per the circuit diagram.
2.   The voltage VCE is kept constant at a particular value.
3.   The voltage VBE is varied in suitable steps and the corresponding current IB is
noted down and the reading are tabulated.
4.   The same procedure is repeated for different constant values of VCE
OUTPUT CHARACTERISTICS:
1.   Connections are given as per the circuits diagram
2.   The base current IB is kept constant at a particular value.
3.   The voltage VCE is varied in suitable steps and the corresponding current IC is
noted down and the readings are tabulated.
4.   The same procedure is repeated for different but constant values of IB.
TABULATION: INPUT CHARACTERISTICS:
VCE in volts                                         VCE in volts

VBE       in volts       IB           in µA.           VBE       in volts       IB       in µA

OUTPUT CHARACTERISITCS:
IB              in µA                                    IB       in µA

VCE       in volts       IC              in mA         VCE           in volts   IC      in mA

H-PARAMETERS CALCULATIONS:
Input impedance                 hie      =        ∆ VBE/∆ IB at constant VCE

Output conductance              hoe      =        ∆ IC / ∆ VCE at constant IB

Forward current Gain            hfe      =        ∆ IC/ ∆ IB at constant VCE
Reverse Voltage Gain          hre       =          ∆ VBE/∆ VCE at constant IB

MODEL GRAPH:
VCE1      VCE2       VCE3

IB in µA

∆ IB

∆ VBE

VBE in volts

IB1

IB2
IC
IB3
mA

VCE(v)

RESULT:
EX.NO:
DATE:

SINGLE STAGE RC COUPLED AMPLIFIER

AIM:
To design the RC coupled amplifier and to determine the frequency response and
bandwidth of the amplifier.

APPARATUS REQUIRED:

SI.NO APPARATUS              RANGE                     TYPE              QUANTITY

1     Power supply         (0-15)V                                    1
2     Resistor(Carbon)    various values                              4
3     Capacitor           various values                              3
4     AFO                                                             1
5     CRO                                                             1
6     Transistor                                    BC107             1

DESIGN:
Let VCC=12V,IC=10mA
According to 1/10 th rule, Ve=VCC/10,
Ve=IeRe; Ie~Ic
Ve= --------
Re= ----------
Rc > 4Re
Let Rc=5Re =5 .120 =600Ω
Vb=Ve+Vbe =1.2+0.7=1.9v

THEORY:

RC coupled amplifier is the most important method of coupling the signal from
one stage to the next. The signal developed across the collector resistor of each stage is
coupled through capacitor in to the base of the next stage. The cascaded stages amplify
the signal and the overall gain is equal to the product of individual stage gains. The
amplifiers, using this coupling scheme, are called RC-coupled amplifier.
PROCEDURE:

1. Connections are made as per the circuit diagram
2. The AFO is connected at the input terminals and the output voltage is set at a fixed
voltage.
3. The AFO is adjusted for different frequency and at each frequency the corresponding
output voltage is noted.
5. A plot of the gain in decibels along the Y-axis and frequency along X-axis is drawn in
the semi log sheet. This plot gives the frequency response.
6. Ahorizontal line at 70.7% of the maximum gain (the 3db line) is drawn parallel to X-
axis. This line will cross the frequency response at two points.
7. These two points are marked as the lower cut off frequency and upper cut off
frequency. The difference between these two frequencies gives the band width of the
single stage RC coupled amplifier.

CIRCUIT DIAGRAM:

VCC=+12V
RC
R1                             CO

CIN
BC107

To CRO
R2
AFO

RE               CE
MODEL GRAPH:

TABULAR COLUMN:
Vin =

Frequency(Hertz)   Output Vo (volts)    Gain in dB[ 20 log
(Vo/Vin)]
QUESTIONS:

1.   Mention the coupling schemes used in amplifiers.
2.   Write the applications of RC coupled amplifier.
4.   What is the difference between RC coupled and direct coupled amplifier?
5.   What is the phase difference between input and output?

INFERENCES:

RESULT:
Exp No:

Date:

EMITTER FOLLOWER

AIM:
To construct the Emitter Follower circuit and to draw the frequency response
characteristics.

APPARATUS REQUIRED:
SNo     Apparatus             Range                Quantity
1       Transistor                                 1
2       Resistors             10k,4.7k,33k,3.3k,1k Each 1
3       Capacitor             1µF,10 µF            1
4       AFO                                        1
5       CRO                                        1
6       Dual power supply     +12v and -12v        1

THEORY:
An emitter follower circuit shown in the figure is widely used in AC
amplification circuits. The input and output of the emitter follower are the base and the
emitter, respectively, therefore this circuit is also called common-collector circuit. It is
negative current feedback circuit that has no voltage gain. It has high input impedance
&low output impedance.

The emitter follower does not amplify voltage, due to its high input
resistance drawing little current from the source, and its low output resistance capable of
driving heavy load, it is widely used as both the input and output stages for a multi-stage
voltage amplification circuit.
CIRCUIT DIAGRAM:

PROCEDURE:

1. The Connections are given as per the circuit diagram.

2. The input voltage is set at a low value.

3. The frequency of the input is valued to the maximum value.

4. The output is noted in the table for each frequency correspondingly.

5. The gain is calculated & the frequency response graph is plotted.
TABULATION:

Frequency    Output    Gain in db.
(HZ)         voltage

MODEL GRAPH:

INFERENCE:

RESULT:
Expt.No :
Date :
APPLICATIONS OF OPERATIONAL AMPLIFIER

AIM:
To study the various applications of op amp such as inverting,Non-Inverting and
Summer.

Apparatus required:

S no      Apparatus                            Range                 Quantity
1         IC                                   741                   1
2         Resistors                            2K                    1
1K                    2
3         AFO                                                        1
4         CRO                                                        1
5         Regulated power supply               0v To 30v             1
6         Dual power supply                    -12v ,+12v            1
8         Wires                                                      reqd

Theory:

Inverting amplifier:
The circuit diagram for the inverting amplifier is shown in fig. The source V IN is
connected in series with R1 and R2. The feedback resistance R2 is connected between
output terminal and inverting input terminal. The resistance R1 is connected to inverting
terminal. The non inverting terminal is grounded. The output voltage VOUT of the
inverting amplifier is given by
VOUT = - [R2/R1 ] VIN
Non Inverting amplifier:
The basic form of non inverting amplifier is shown in fig. Here source V IN is
connected with non inverting input terminal. The output voltage VOUT is given by

VOUT = [1+ (R2/R1)] VIN
Pin details of LM 741

LM 741

Circuit diagram:
Inverting amplifier

Non Inverting amplifier

Procedure:
1. Give the circuit connection as per the circuit diagram.
2. Give the sine wave (or square wave) to the input terminal of OPAMP from AFO
(Audio Frequency Oscillator).
3. Set the output and input waveforms in CRO.
4. Observe the amplitude and time of the output and input waveforms.
5. Note down the phase shift of the input and output waveforms.
6. Find the voltage gain (VOUT/VIN ) and compare it with design value.
7. Draw the input and output waveforms.
Tabulation:
X-axis         Time           Y-axis          Amplitude
No of div    Volt/div
No of div     Time/div
Inv amp
Input
Output
Non inv
amp
Input
Output

Model calculation:

\
Model graph for inverting and non inverting amplifier:

Inverting amplifier:

Non inverting amplifier:
Inference:

Result:

Summer: The output of the circuit is the several sums of the input signals

CIRCUIT DIAGRAM:
SUMMER:

Vo=(Rf/R1)V1+ (Rf/ R2)V2+ (Rf/R3)V3

If R1=R2=R3=Rf
Vo = V1 + V2 + V3
PROCEDURE:
SUMMER
1. Connections are given as per the circuit diagram
2. According to the gain, find the resistors value.
3. The dc voltages are given at the inputs
4. The dc voltage levels are minimized such that their sum does not take the op amp
into saturation
5. The output voltage is measured with the help of a multimeter.it will be negative
sum of the inputs.
6. Compare the theoretical and practical value.

TABULATION: SUMMER

Input voltage     Gain             Practical output      Theoretical
(V)                                voltage (V)           output voltage
(V)

QUESTIONS:
1. Write the applications of op amp?
2. What is the advantage of instrumentation amplifier?
3. What is the use of capacitively coupled amplifier?
4. List out the linear & non linear circuits
5. Draw the internal block diagram of an op amp

INFERENCE:

RESULT:
Ex No:
Date

INTEGRATOR AND DIFFERENTIATOR

Aim

To study the application of operational amplifier as Integrator and
Differentiator
Apparatus Required

SNo   Apparatus           Range           Quantity
1     IC 741                              1
2     Resistors           22K             1
3     Capacitor           0.01µF          1
4     AFO                                 1
5     CRO                                 1
6     Dual power supply   +12v and -12v   1
8     Wires                               reqd

Theory:

An integrator circuit produces integration of input voltage.

A differentiator circuit produces differentiation of input voltage. One of
the simplest of the op-amp circuits that contain capacitor is the
differentiator. As the name suggests, the circuit performs the
mathematical operation of differentiation. (i.e.) the output waveform is
the derivative of input waveform.

Pin details:

LM 741
Circuit diagram:
Integrator

t
1
RC 
V0        Vi dt  C   where C=0
0

Differentiator
Procedure

1. The connections are given as per the circuit diagram
2. The output waveforms for the given input waveforms are noted
3 The readings are noted in the given table

Inference:

Result:

Tabulation:

X-axis        Time           Y-axis        Amplitude
No of
No of                                   Volt/div
Time/div           div
div
Integrator:
Input
Output
Differentiator:
Input
Output
Model graphs:

Integrator                                 Differentiator

Graph:
X-axis time & Y-axis-amplitude

Integrator                       Differentiator
Input               Output       Input               Output
Square                           Triangular
Sine                             Sine
Triangular                       Square
EX.NO:
DATE:
WEIN BRIDGE OSCILLTAOR

AIM:
To design and construct a wein bridge oscillator whose frequency of oscillation fo=

APPARATUS REQUIRED:

SNo APPARATUS                    TYPE/RANGE            QUANTITY

1     IC                                741                       1
2     Power Supply                  12 to -12V                    1
4     Resistors
5     AFO,CRO                         --------              Each one
6     Wires                             -----                  15
7     Capacitor

THEORY:

One of the most commonly used audio frequency oscillator is the wein bridge
oscillator. the Barkhausen criterion for oscillation is that total phase shift around the
circuit must be 0 or 360. The condition occurs only when the bridge is balanced that is at
resonance. The frequency of oscillation is given by Fo=1/2ПRC
At this frequency gain required for sustained oscillation is given by

Av=1/β=3
i.e 1+Rf/R1=3

Rf=2R1

CALCULATIONS:
Fo=1/2П(R1R2C1C2)1/2
At this frequency the gain required for sustained oscillation is
1+Rf/R1=3
Rf=2R1
Given Fo=-----------kHz
Let R1=R2=R,       C1=C2=C
Fo=1/2ПRC
R=1/2ПfoC
CIRCUIT DIAGRAM:

PROCEDURE:

1. The connections are given as per the circuit diagram
2. The supply is applied
3. According to the design resistors, capacitor value.
4. The feedback resistor of the op amp is varied so as to meet the voltage gain
requirement of the circuit
5. Check the output by using CRO
6. Compare the theoretical & practical value of frequency.

TABULATION
No of      Time/div (ms)     Volts/div     Amplitude    Time period (ms)
divisions
x-axis y-axis

QUESTIONS:
1. What is an oscillator?
2. Draw the block diagram of feedback oscillator?
3. What are the two conditions of oscillations
4. Write the classification of oscillator
5. What is the difference between positive feedback & negative feedback?
MODEL GRAPH:

INFERENCE:

RESULT:
EX.NO:
DATE:
RECTANGULAR WAVE AND TRIANGULAR WAVE
GENERATOR
RECTANGULAR WAVE GENERATOR

AIM:
(i) To design, construct & test a Rectangular wave generator circuit whose frequency of
oscillation is fo =      Hz.
(ii) Compare theoretical & practical frequency.

APPARATUS REQUIRED:
APPARATUS          TYPE                       RANGE                   QTY
IC 741                                                                1
Fixed power supply Dual                       ± 12 V                  1
CRO                                                                   1
Resistors                                     Design values           3
Capacitor                                     Design value            1

THEORY:
This circuit is also called free running oscillator. The principle of generation of
square wave output is to force an op amp to operate in the saturation region. A fraction,
R1
              , of the output is given as feedback to the (+) input terminal. Thus the
R1  R2 
reference voltage Vref is βVo and may take values as + βVsat or - βVsat. The output is also
feedback to the (-) terminal after integrating by means of a low pass RC combination.
Whenever input at the (-) input terminal just exceeds Vref, switching takes place, resulting
in a square wave output. In astable multivibrator both the states are quasi stable.
When Vo = +Vsat, capacitor starts charging towards +Vsat through R. The voltage
at the (+) input terminal is held at βVsat by R1 & R2 combination. This condition
continues while the charge on C rises, until it has just exceeded + βVsat (the reference
voltage). When the voltage at the (-) input terminal becomes just greater than the
reference voltage, the output is driven to -Vsat. At this instant, the voltage on the capacitor
is + βVsat. It begins to discharge through R i.e. it charges towards –Vsat. When the output
voltage switches to –Vsat, the capacitor charges more negatively until its voltage just
exceeds – βVsat. At this instant, the output switches back to +Vsat and the cycle repeats
itself.
PROCEDURE:
1. Connections are given as per the circuit diagram.
2. Resistor& capacitor values are put according to the design.
3. Square wave output is checked using a CRO

CIRCUIT DIAGRAM:
Rf

+Vsat
C                  +12 V
2          7
–                            Vo (V)
6
741               Vo
3    +
4
-12 V

R2
R1                                -Vsat
Time (ms)
Rectangular wave
generator

TABULATION:
No of Div     No of Div                Time /Div      Volt/Div Time Period        Amplitude
in X Axis     in Y Axis                                        (ms)               (V)

QUESTIONS:
1.   What is a multivibrator?
2.   How many stable states are there in an astable multivibrator?
3.   How many quasi states are there in an astable multivibrator
4.   Why the name astable multivibrator is given to the circuit above?
5.   Is there any other method to generate square wave without giving an input signal?

INFERENCE:
RESULT:
TRIANGULAR WAVE GENERATOR

AIM:
(i) To design construct & test a triangular wave generator circuit whose frequency of
oscillation is fo =     Hz.

(ii) Compare theoretical & practical frequency.

APPARATUS REQUIRED:
APPARATUS          TYPE                        RANGE                        QTY
IC 741                                                                      2
Fixed power supply Dual                        ±12 V                        1
CRO                                                                         1
Resistors                                      Design values                3
Capacitor                                                                   1

THEORY:
Triangular waveform can be simply obtained by integrating a square wave.
Although the amplitude of the square wave is constant at +/- Vsat, the amplitude of the
triangular wave will decrease as the frequency increases. This is because the reactance of
the capacitor (C) in the feedback circuit decreases with increasing frequency.

CIRCUIT DIAGRAM:
+Vsat

C1
-Vsat
+12 V                                                       t
2          7
–                  R1
+12 V
6            2          7           +Vramp
741                         –                  Vo
3                                                  6
+     4
741
-12 V                3    +     4           -Vramp
-12 V                       t

R3
R2
Triangular wave
generator
MODEL CALCULATION

1    R3
fo      
T 4 R1C1 R2

PROCEDURE:
1. Connections are given as per the circuit diagram;
2. Resistor& capacitor values are put according to the design.
3. Triangular wave output is checked using a CRO and verified with theoretical values
of frequency.

MODEL GRAPH:

+Vsat

Vo’ (V)

-Vsat

+Vramp

Vo (V)

-Vramp                                   Time (ms)

TABULATION:
No of Div       No of Div      Time /Div       Volt/Div        Time        Voltage
in X Axis       in Y Axis                                      (ms)        (V)
INFERENCE:

RESULT:
EXP NO:
DATE:
RTD, THERMISTOR CHARACTERISTICS

a)RTD characteristics.

Aim: To study the characteristics of resistance temperature detector and thermistor
for various temperatures.

Components required: RTD, RTD module trainer kit, Multimeter.

Theory questions:

01. Define RTD and write the equation relating the temperature and resistance.
02. What are the various materials used for RTD. Draw the graph showing the
relationship between temperature and resistance for various materials of RTD.
03. How will you approximate the resistance versus temperature curve for RTD.
04. What are the requirements of the materials to be used for RTD?

Panel diagram: Draw the front panel diagram showing the signal conditioning
circuit and display unit by seeing the trainer kit.

THEORY:
THERMISTORS:
Thermistors are semi conductors of ceramic that are exceptionally sensitive to
temperature. The material is made by entering oxides of such material is
magnance,nickel,cobalt,copper,iron ,etc..,physical forms of thermistors are
beads,disks,washes and rods. The temperature co-efficient of resistivity metallic
oxides semiconductors is negative. The resistance relationship thermistors are
decreases as the temperature increases.

Procedure:
i) To study the temperature versus resistance characteristics of RTD.

01. Ensure that the power to the unit is switched off.
02. Connect the ohm meter across the RTD.
03. Insert the RTD into the water bath note the resistance offered at room
temperature.
04. Heat the water and note the values of temperature and resistance.
05. Repeat step 4 for different values of temperature and tabulate the reading.

ii) To study the temperature versus voltage and the accuracy of the signal
conditioning board.
01. Connect the RTD to the trainer kit in the socket provided.
02. Switch on the power supply to the unit.
03. Insert the RTD and thermometer into water bath and note the temperature without
heating at ambient condition.
04. If there is any difference in temperature between that noted and displayed in the
front panel, adjust the offset knob to vary the displayed temperature to tally with
the actual temperature. Else this knob must be undisturbed.
05. Connect the multimeter in voltage mode at point T1 with respect to ground.
06. Now gradually start heating the water bath and note down the actual temperature
07. Repeat step 06 for different values of temperature and tabulate the readings.
08. Calculate the percentage error.
Displayed Temperature – Actual Temperature* 100
% Error =             Actual Temperature

Tabulation:
Room Temperature =         °C

Sl.No    Temperature in ° C     Resistance in Ω

Room Temperature = ° C

Sl.       Actual       Displayed       Output         Error in
No     temperature    Temperature     Voltage in         %
in    °C        in ° C          volts
Graph: A graph is drawn between Actual temperature(X – axis) and Displayed
temperature, Voltage, Resistance (Y – axis)

Inference:

Result:

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Description: This is manual for the practical lab classes for basic electronics students. It contains the basic experiments with the aim, apparatus required, circuit diagram, tabulation for observations, results and graphs with the model graphs.
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