G.H. RAISONI COLLEGE OF ENGINEERING, NAGPUR
Department of Electronics and Communication Engineering
Branch: -6th Semester [Electronics And Telecommunication]
Subject: - Control Systems
List Of Experiments
Sr.
Name of Experiment
No
1
To study Synchro Transmitter
2
To study Synchro Transmitter and Receiver in pair
3
To plot speed – torque characteristics & speed Vs back emf characteristics
of A.C servomotor.
4
To measure basic step angle of Stepper Motor
5
To study potentiometer as a transducer and error detector.
6
To study the time response of simulated Linear Systems Simulator
7
To plot Root locus by Using MATLAB Software
8
To study transient response of second order system using R, L, C series
circuit.
Experiment No: 1
Aim: - To study Synchro Transmitter
Apparatus: - 1) Synchro
2) Multimeter
Circuit Diagram: S2
STATOR
WINDING OF
TRANSMITTER
V
V/2
V/2
V12
V23
S1
S3
V31
R1
ROTOR
WINDING OF
TRANSMITTER
R2
AC LINE
TORQUE TRANSMISSION USING SYNCHRO TRANMITTER
Theory:- Theory should cover details about following points.
Procedure: -
1
2
3
4
5
Constructional details of Synchro Transmitter
Constructional details of Synchro Receiver
Operation of Synchro Transmitter Receiver in pairs.
Advantages and disadvantages of Synchro.
Application of Synchro.
1)
2)
3)
4)
Connect the system to main supply
Switch on the main switch and SW1
Do not connect any wires between the stator winding of TX & TR.
Starting from zero position (i.e. Knob of synchro transmitter at 0 degree) note- down
the voltages between stator terminals i.e. VS S1 , VS2S3 , & VS3 S4 in a sequential
fashion .
5) Rotate the knob by 30 degree and again note down Vs1S2 , VS2S3 & VS3 S1
6) Repeat step no.05 for further rotation by 30 degree (i.e. knob at 60 degree now)
2
7) Like this make one complete rotation of 36 degree and note the readings in a tabular
form.
Observation Table: Sr. No
1
2
3
4
5
6
7.
12
13
Position of
Rotor in
Degrees
0 degree
30 degree
60 degree
.
.
.
Stator Voltage or terminal voltage ( RMS value )
Vs1S2
VS2S3
VS3S1
330 degree
360 degree
Graph: - Plot a graph of angular position VS voltage for all the three phases .
Result: -The synchro Transmitter was studied and waveform of stator winding voltages was
plotted on graph .
Conclusion: - : It is observed that due to transformer action, the angular position of
rotor is transferred into a unique set of stator voltage, viz. VS1S2 , VS2.S3 & VS2S1.
Viva Questions:
1) Explain the working of synchro – transmitter as transducer?
2) Write application of synchro – transmitter as transducer?
3
Experiment No: 2
Aim: -To study Synchro Transmitter and Receiver in pair.
Apparatus: - Synchro Transmitter & Receiver Kit
4
Circuit Diagram :S2
S2
STATOR
WINDING OF
TRANSMITTER
V
STATOR
WINDING OF
RECEIVER
V
V/2
V/2
S1
V/2
S3
V/2
S1
S3
R1
R1
ROTOR
WINDING OF
TRANSMITTER
ROTOR WINDING
OF RECEIVER
R2
R2
AC LINE
TORQUE TRANSMISSION USING SYNCHRO TRANMITTER
S2
STATOR
WINDING OF
TRANSMITTER
S2
STATOR
WINDING OF
RECEIVER
3V/2
0
3V/2
S1
3V/2
3V/2
0
S3
S1
S3
30
ROTOR
WINDING OF
TRANSMITTER
R2
ROTOR WINDING
OF RECEIVER
R2
AC LINE
TORQUE TRANSMISSION USING SYNCHRO
TRANMITTER AND RECEIVER AS PAIR
Theory: -Theory should cover details about following points.
2.
3.
4.
Constructional details of Synchro Transmitter
Constructional details of Synchro Receiver
Operation of synchro transmitter receiver in pair.
5
5.
6.
Advantages and disadvantages of synchro.
Application of synchro.
Procedure: -
1) Connect the system to main supply
2) With the help of patch cord establish connections between corresponding terminals of
TX & TR stators. i.e. connect S1 to S1 , S2to S2 and S3 to S3 of TX & TR stator
respectively .
3) Switch on SW1 & SW2 as well as main of instrument.
4) Move the pointer (rotor position of TX in steps of 30 degrees and observe the new
position of TR.
5) Enter the input angular position & output angular position in the tabulator from &
plot the graph.
Obseravtion Table: Sr. No
Synchro Transmitter
0
30
1.
2.
.
.
.
12.
13.
Synchro Receiver
330
360 = 0 degree
Graph: - Plot the graph between O/P angular position ( Receiver side ) Vs input
angular position ( Transmitter side )
Result: - The Synchro Transmitter Receiver in pair or as an error detector was studied .
Conclusion:Viva Questions:
1)
2)
Compare the constructional difference between the synchro –
transmitter and synchro-receiver?
Write the application of the synchro –transmitter and synchro-receiver
as pair?
Experiment No: 3
Aim: - To plot speed – torque characteristics & speed Vs back emf characteristics of
A.C servomotor .
Apparatus: -
6
1) AC Servomotor set
2) Multimeter
Circuit Diagram: 10K /8W
110V
P1
C /1mfd
A.C.
230V
0V
ROTATING
DISC
REF. WINDING
DCM
ACSM
-
Eb
+
LIGHT
SOURC
E
TP1
P2
VR
(TP2)
SPEED
CALIBERATION
SIGNAL
PROCESSING
PCB2
M1
LOAD
CONTROL
PHOTO
PICKUP
-
M2
TP3
E
RECTIFIER AND
REGULATOR
PCB 1 -- PCB3
RPM
TP2
+
TO
LAMP
BLOCK DIAGRAM OF AC SERVOMOTOR
Theory: -
Theory should cover details about following points
1) Description of set up.
2) What is Servomotor? Give their classification in brief?
3) The requirements or desirable features of servomotors.
4) Constructional details of AC Servomotors.
5) Working
7
6) Point of differences between AC servomotor & normal Induction Motor.
7) Application
Procedure: -
1) Study all the controls carefully on the front panel. Keep the switch SW1,
in upward position, indicating that the armature circuit of dc. Machine is
not connected o Auxiliary power supply, switch SW2 should also be in
off position.
2) Ensure P1 & p2 are in fully anticlockwise position.
3) Note switch ON SW1 & also switch SW2, you can observe that AC
servomotor will start rotating & the speed will be Indicated by the meter M1
on the front panel .
4) Also SW3 in OFF condition, vary the speed of by moving P1 in a clockwise
direction and note the emf. gnerated by the D.C. machine ( now working as a
dc generator or tacho) At terminal Tp1 . Enter the results in Table no-01 (
Use a DC voltmeter in the range of 0-to 2 volt or so .)
5) Now switch SW3 , in off condition , switch ON SW2 and keep the pot , P1
in minimum position / You can observe that the AC servomotor starts
moving with speed being indicated by the RPM indicator . You can measure
the reference winding voltage (which is variable by pot P1)
6) Set the control winding voltage to 35 volt and the note the speed of A.C.
Servomotor by controlling Pot P2 in a slow fashion. Note down corresponding
values of Ia & on meter M2 & RPM meter M1 respectively. Enter these values
in Table 2.
8) Now switch off SW3 & set the control wining voltages to 45 volt & 55 volt
respectively & repeat the procedure as in step 5 .
9) Polt the speed torque characteristics for various values of control winding
voltage.
Observation Table : -
TABLE NO:- 01
(Table indicates only procedure)
Sr.No
N
Eb ( in volt)
8
1
2
3
4
5
6
-
(in RPM )
1175
1125
1100
-----
-1.35
-1.31
-1.26
-----
TABLE NO:- 02
(Table indicates only procedure )
Control winding voltage = Vc = 35 volt .
Sr.No I
(in MA)
1
0
2
200
3
300
4
-.
-.
---
Speed N
( in PM )
1475
1400
1350
-----
Eb
( in volts )
1.47
1.4
1.35
-----
Pmw = ( Eb ) .(Ia)
( in mill watt)
0
280
405
-----
Torque in
(gm-cm)
0
19.46
29.19
-----
Note: - Torque ‘T’= ( P* 1.019* 104 *60 / 2 N …… gm = Cm
Graph: - 1) Plot a graph for back e.m.f. ( in mV) Vs speed in RPM
2) Torque -speed characteristics of AC servomotor
Result: - Torque speed characteristics for AC servomotor & back e.m.f. Vs speed
characteristics was studied and graph are plotted.
Conclusion: -
Note the readings in a tabular form.
Viva Questions: -
1) What is Servomotor? Give their classification in brief
2) Explain the torque – speed characteristics of AC servomotor?
Experiment No: 4
Aim: - To measure basic step angle of Stepper Motor
Apparatus: - Stepper motor set up.
9
Circuit Diagram: STEPPER MOTOR
PANEL DRAWING
SINGLE STEP
CW
FREE
RUN
CCW
WOBLE
PULSE
SEQUENCE
GENERATOR
PHASE
uP
INTERFACE
1
2
POWER
DRIVER
3
4
FREQ
ON
Y
TRIG
Theory: - Theory should cover details about the following points .
1
3)
4)
5)
Equipment description.
Construction of stepper motor
Working
Application
Procedure: 1)
2)
3)
4)
5)
Connect the motor unit to main unit & switch on the supply
Keep switch S1 to manual stepping.
Select clockwise (CW) rotation.
Connect all phases to the corresponding drives.
Press the manual stepping push button inn multiples of 10 pulses & note the
change in angular position from the dial
6) Calculate the average basic step angle.
7) Repeat the above step selecting counter clockwise (CCW) directions rotation.
Observation Table:Sr. No
Direction of
Rotation
Angle
subtended in 10
steps ( in
Angle
subtended in
one step ( in
Average basic
step angle ( in
degrees)
10
1.
2.
CW
CCw
degrees )
---------
degrees)
---------
--------
Result:- Basic step angle of stepper motor in found to be …………………….
Conclusion:Viva Questions: -
1) Explain the different types of stepper motor?
2) What is importance of stepper motor as per industrial purpose?
3) Write the application of stepper motor?
Experiment No: 5
Aim: - To study potentiometer as a transducer and error detector.
Apparatus: - 1) 10 Turn precision helical potentiometer
2) Multimeter
11
Circuit Diagram: -
POTENTIOMETRIC ERROR DETECTOR
ON
2.21
AC
VOLTS
EXCITATION
DC
POT 2
POT 1
+
BALANCED
DEMODULATOR
_
AC / DC
EXCITATION
INSRUMENTATION
AMPLIFIER
POT 1
POT 2
BALANCED DEMODULATOR
V1
V2
+
_
Vo
CARRIER
(Internal)
SCHEMATIC DIAGRAM
Theory: - Theory should cover details about following points.
1) Equipment Description
2) Building Blocks
3) Experimental Work
Procedure: - 1) Connect the main cord to supply line & switch on the main switch &
12
device button.
2) Adjust the output voltage of potentiometer to zero by rotating the knob
of potentiometer in anticlockwise direction. (note that we are using
only one side i.e. one potentiometer).
3) Measure the input voltage between I/P and ground.
4) Now rotate potentiometer knob by one rotation i.e. 3600 & measure o/p
voltage between terminals, O/P & ground. It will be approximately
(1/10)th of I/P voltage (Because the potentiometer on which we are
working is 10 turn potentiometer) .
5) Repeat step no 4 ten times. At the end of tenth rotation O/P voltage is
equal to input voltage.
Observation Table: Sr. No.
1
Angular Position (in
Degrees)
100
3600
7500
10800
Output voltage (in Volts)
0
3.6
0.72
1.08
Graph: - Plot a graph for angular position Vs O/P voltage
Result: - Potentiometer as a transducer was studied & graph is plotted
between angular position Vs output voltage.
Conclusion: Viva Questions: 1) Explain the working of potentiometer?
2) Write the application of potentiometer?
Experiment No: 6
Aim: - To study the time response of simulated Linear Systems Simulator
Apparatus: - Linear System Simulator KIT
Circuit Diagram: -
13
Rs
+
Cs
K1
----S
K
- 1
Rs
+
K3
-----------ST2 + 1
K
Cs
-1
CLOSED LOOP OPTION FOR FIRST ORDER
SYSTEMS
DECISION
MAKING
SYSTEM
Cs
+
REFERENCE OR
COMMAND
G(s)
-
MEASUREMENT
BLOCKED DIAGRAM OF A CLOSED LOOP SYSTEM
14
C(t)
Y(t)
K
-S
1
t
t
r(t)
C(t)
K
---------ST + 1
1
C(t) = Kt
K
.632K
t
C(t) = K(1 - e-t/T)
T
t
UNIT STEP RESPONSE OF FIRST ORDER TRANSFER FUNCTIONS
Theory: - Theory should cover details about the following points.
1
2
3
4
Equipment description.
Construction of Linear System Simulator
Working
Application
Procedure: - For Open Loop Response
1) Note down the value of K1, K2, K3 and T1 , T2
2) Error detector cum variable gain
a) Apply a 100 mV square wave signal to any of the three inputs
b) Set the gain setting potentiometer to 10.0( v=0)
c) Measure the P-P output voltage and note its sign. Calculate the
gain. This is the maximum value of gain.
d) Repeats for other two inputs.
e) Write the equation of this block and verify by connecting the signal
to all three inputs.
3) Disturbance adder
a) Test it in same manner as a)
4) Uncommitted amplifier
a) Apply a 1 volt p-p square input .
b) Measure the p-p output voltage and note its sign.
c) Record the equation of this block for later use.
5) Integrator
a) Apply a 1 volt p-p square input.
b) Measure the p-p output voltage and note its sign.
c) Calculate the gain constant K of integrator and write transfer
function of block.
15
6) Time constant
a) Apply 100mV p-p square wave of known frequency to ensure that
steady state.
b) Find on the trace the time t= T, where response reaches to 63.2 %.
c) K= ( p-p steady state output / p-p input amplitude )
d) Write transfer function of block
First Order System - Closed Loop Response
b) Apply a 1 volt p-p square input. trace the o/p waveforms , for K=
0.5 , 1.0, 1.5 ………….
c) Calculate the time constant in each case compare it with
theoretical results.
d) Calculate steady state errors for the above case .
e) To find steady state error for ramp input, apply 1V p-p triangular
wave input . connect system i/p to X input and output to Y input
f) The vertical displacement between the two curves is the steady
state error.
g) Repeat the measurement for different values of K and compare
the results with theoretical values.
Result: - We studied the first order open loop and closed loop system with linear system
simulator.
Viva Questions: 1) Explain the different standard input of control system?
2) Explain the effect of feedback element on control system?
16
Experiment No: 7
Aim: - To plot Root locus by Using MATLAB Software
Problem: - Sketch the root locus for the transfer function given below.
10
G(S) = --------------------------------------S (S+1) (S+2) (S+4)
Theory: - Theory should cover the following points .
1) Explain about MATLAB Software
2) Write steps to plot Root Locus
3) Advantages of using software for analysis.
Procedure:- 1) Solve the problem manually
2) By using MATLAB software feed the data as above problem.
3) Do the analysis by MATLAB software
4) Compare both the result
Result: -
Result obtained manually are as results obtained by software .
By using software we can do analysis of large system.
17
Experiment No: 8
Aim: - To study transient response of second order system using R, L, C series circuit.
Apparatus: -
1)
2)
3)
4)
5)
Function Generator
Cathode Ray oscilloscope
Capacitance box
Resistance box
Inductance box
Circuit Diagram: -
Theory: -
The theory should contain the details about following points .
1.
Definition of Time response , Transient response and steady state
response
2.
Type and order of system.
3.
Time response specification viz. Delay time ., rise time Peak time ,
Overshoot , Settling time , steady state error ( write down expressions
for these specification )
Procedure: -
(1) Connect R, L, C in series and give supply to this series combination
through function generator . Connect CRO across capacitance box.
(2) Give a supply of 2 volt ( peak to peak) by function generator .(
Measure this on CRO )
(3) By varying R, L, C as well as adjusting frequency to a suitable get the
time response on CRO.
(4) Note all the time response specifications and draw the response on graph
paper.
18
Observation Table: Input voltage (P-P) =-------------------------- Input frequency: --------------------------Sr.
No
1
2.
3.
R
L
C
tr
tp
% Mp
Specimen Calculation:(1)
l.C)
(3)
tr = -----------------
(4) % Mp = 100 e -
Graph : - Sketch the complete time response on graph paper .
Result: - The time response of second order RLC series circuit was studied and plotted
on graph paper.
Viva Questions:
1) Explain the steady state and transient response?
2) Explain the classification of control system according to the
damping ratio?
19