hik
w.
ww
Power Electronics Lab
ST2712
-c
Operating Manual
on
Ver 1.1
94-101, Electronic Complex Pardesipura,
Indore- 452010, INDIA
Tel : 91-731- 2570301/02, 4211100
Fax: 91- 731- 2555643
E-mail : info@scientech.bz
Website : www.scientech.bz
Toll free No. : 1800-103-5050
pl
g.
ltin
su
An ISO 9001 : 2000 company
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
2
pl
hik
w.
ww
ST2712
Power Electronics Lab
ST2712
Table of Contents
1.
Safety Instructions
5
2.
Introduction
6
3.
Features
7
4.
Technical Specifications
8
5.
Functions of Various Blocks
9
6.
Operating Instructions & Panel Control Description
7.
Experiments
10
Experiment 1
Study of the V-I Characteristics of SCR
11
•
Experiment 2
Study of the V-I Characteristics of UJT
13
•
Experiment 3
Study of the V-I Characteristics of MOSFET
15
•
Experiment 4
Study of the V-I Characteristics of IGBT
17
•
Experiment 5
Study of the V-I characteristics of DIAC
19
•
Experiment 6
Study of the V-I Characteristics of TRIAC
21
•
Experiment 7
Study of the V-I Characteristics of PUT
23
•
Experiment 8
Study of the Class B Commutation Circuit
25
•
Experiment 9
Study of the Class C Commutation Circuit
27
•
Experiment 10
Study of the Class D Commutation Circuit
•
Experiment 11
Study of the Class F Commutation Circuit
•
Experiment 12
Study of R Triggering Circuit
•
Experiment 13
Scientech Technologies Pvt. Ltd.
g.
ltin
su
on
-c
•
29
31
33
35
3
pl
hik
w.
ww
ST2712
Study of RC (Half Wave) Triggering Circuit
Experiment 14
Study of RC (Full Wave) Triggering Circuit
37
•
Experiment 15
Study of the SCR Triggered by UJT
39
•
Experiment 16
Study of the SCR Triggered by 555IC
41
•
Experiment 17
Study of the SCR Triggered by Op-Amp 741IC
43
•
Experiment 18
Study of the Ramp and Pedestal Triggering Circuit with AntiParallel SCR in AC Load
45
•
Experiment 19
Study of the UJT Relaxation Oscillator
46
•
Experiment 20
Study of the Voltage Commutated Chopper
50
•
Experiment 21
Study of the Bedford Inverter
52
•
Experiment 22
Study of the Single Phase PWM Inverter using MOSFET and IGBT
54
•
Experiment 23
Study of the Half Wave Controlled Rectifier with R and RL Load
56
•
Experiment 24
Study of the Full Wave Controlled mid-point rectifier with R and RL
Load
61
•
Experiment 25
Study of the Fully Controlled Bridge Rectifier with R and RL Load
8.
Data Sheets
9.
Warranty
10.
List of Accessories
11.
List of other Trainers available from us are
Scientech Technologies Pvt. Ltd.
65
71
85
85
g.
ltin
su
on
-c
•
86
4
pl
hik
w.
ww
ST2712
Safety Instructions
Read the following safety instructions carefully before operating the instrument. To
avoid any personal injury or damage to the instrument or any product connected to it.
Do not operate the instrument if suspect any damage within.
The instrument should be serviced by qualified personnel only.
For your safety :
: Use only the mains cord designed for this instrument.
Ensure that the mains cord is suitable for your
country.
Ground the Instrument
: This instrument is grounded through the protective
earth conductor of the mains cord. To avoid electric
shock the grounding conductor must be connected to
the earth ground. Before making connections to the
input terminals, ensure that the instrument is properly
grounded.
-c
Use proper Mains cord
Observe Terminal Ratings : To avoid fire or shock hazards, observe all ratings and
marks on the instrument.
: Use the fuse type and rating specified for this
instrument.
on
Use only the proper Fuse
Use in proper Atmosphere : Please refer to operating conditions given in the
manual.
Do not operate in wet / damp conditions.
2.
Do not operate in an explosive atmosphere.
g.
ltin
su
Scientech Technologies Pvt. Ltd.
1.
5
pl
hik
w.
ww
ST2712
Introduction
ST2712 Power Electronics Lab is useful Trainer to perform Power Electronics
experiments. This trainer is very useful for student to know about the characteristics
of power electronics devices and their applications.
This Trainer is equipped with following blocks for power electronics experiments
DC supply.
•
AC supply.
•
Triggering circuit.
•
Pulse amplifier with Isolation transformer.
•
Separate Pulse transformer section.
•
Single phase rectifier firing circuit.
•
SCR assembly.
•
Load section.
•
Power Apparatus section.
su
on
-c
•
RoHS Compliance
Scientech Products are RoHS Complied.
g.
ltin
RoHS Directive concerns with the restrictive use of Hazardous substances (Pb,
Cd, Cr, Hg, Br compounds) in electric and electronic equipments.
Scientech products are “Lead Free” and “Environment Friendly”.
It is mandatory that service engineers use lead free solder wire and use the
soldering irons upto (25 W) that reach a temperature of 450°C at the tip as the
melting temperature of the unleaded solder is higher than the leaded solder.
Scientech Technologies Pvt. Ltd.
6
pl
hik
w.
ww
ST2712
Features
Self contained & easy to operate
•
Functional blocks indicated on board mimic
•
Solder less breadboard
•
On board DC` power supply
•
On board AC power supply
•
Onboard pulse generator with PWM control, frequency control and duty
cycle control
•
On board single phase rectifier firing circuit with firing angle control
•
On board power electronic devices
•
On board pulse amplifier and isolation transformer section
•
Load selection
•
Rotary Switch provided to select the value of the load
Scientech Technologies Pvt. Ltd.
g.
ltin
su
on
-c
•
7
pl
hik
w.
ww
ST2712
Technical Specifications
:
172.5 mm x 128.5mm
DC Power Supply on board
:
+5 V, -5 V; 500 mA,
+12V, -12 V; 500 mA
+15 V; 250 mA
+35V; -35V, 250 mA
AC Power Supply on Board
:
18V-0V-18V
0V-15V
Triggering Circuit on Board
:
5 gate signal output.
Frequency range: 30Hz to 900Hz
Variable.
Amplitude: 12V.
PWM control of G1, G2, G3 and G4
Duty cycle control of “Gate”
Signal is 0 to 100%.
Single Phase Rectifier
:
Firing angle control 0 º-180 º variables.
-c
Size of Breadboard
Firing Circuit on Board
Four gate signal output with isolation
SCR Assembly
:
4 SCRs 2P4M, 600V, 2A
Power Devices
:
IGBT G4BC20S, MOSFET IRF Z44N,
on
UJT 2N2646, DIAC DB3, TRIAC BT136,
PUT 2N6027, SCR TYN616
Circuit Components on Board
:
Electrolytic Capacitor 10µF, 63V
Electrolytic Capacitor 1µF, 63V
Met. Capacitor 0.33µF, 63V
su
Diode 1N4007,
Inductor 220µH, 4.7µH, 10mH
Pulse transformer on Board
:
2 nos. PT4502 1:1 and one is PT4503 1:1:1
Load selector
:
6 load resistances- 47E/7W, 1K/1W, 1K/10W,
270E/5W, 120E/5W, 2K2 /2W
g.
ltin
Test points
:
10 in numbers
Weight
:
5 Kgs. (approximately)
Dimensions (mm)
:
W420 x H100 x D255
Power requirement
:
230V +/- 10%; 50 Hz.
Power consumption
:
4VA (approximately)
Scientech Technologies Pvt. Ltd.
8
pl
hik
w.
ww
ST2712
Functions of Various Blocks
DC Power :
This block provides fixed DC output of +5 V and -5 V, +12V and-12V, +15V, +35V
and -35V.
AC Power :
This block provides fixed AC output of 18V-0V-18V and 0V-15V.
Triggering Circuit :
This block generates 4 gate pulses of frequency range 30Hz to 900Hz with PWM
control and frequency control and 1 “Gate” signal with duty cycle control 0 to 100%.
Single Phase Rectifier Firing Circuit :
This block provides 4 gate and cathode signals with isolation for single phase
controlled rectifiers. Firing angle control using Potentiometer from 0 to 180 degree.
Pulse amplifier and isolation transformer :
-c
This block provides amplification of gate signal and isolation between power circuit
and triggering circuit. In which toggle switch for select 2 or 4 number of outputs with
2 different signals. When we select 4 signals then output is 4 signals with 2 signals are
same but isolated.
SCR Assembly, Power Devices, Circuit Components :
Load section :
on
This block provides 4 SCRs, IGBT, MOSFET, PUT, UJT, DIAC, and TRIAC, 3
Diodes 1N4007, and Ele. Cap. 1µF/63V, MET. 0.1µF/63V and MET.
Cap.0.33µF/63V. Inductors 68mH, 10mH.
This block provides different loads 1K/1W, 1K/10W, 120E/5W, 47E/7W, 2K2/2W,
270E/5W. This load is selected by selector switch.
su
Pulse transformer :
This block provides pulse transformers for circuit isolation. In this block 2
transformers of 1:1 and one is 1:1:1.
g.
ltin
Scientech Technologies Pvt. Ltd.
9
pl
hik
w.
ww
ST2712
Operating Instructions and Panel Control Description
The trainer is equipped with built in DC and AC power supply. When ‘On/Off’ switch
of the trainer is turned ‘On’, the power LED indicates that trainer is ‘On’ and Various
DC and AC supply are also ‘On’.
Frequency potentiometer of triggering circuit is used for varying the frequency of
pulse signals G1, G2, G3, G4 and Gate. PWM potentiometer of triggering circuit is
used to vary the pulse width for inverter circuit. Duty cycle control potentiometer for
varying duty cycle of only “Gate” signal for speed control using MOSFET.
In the single phase rectifier firing circuit there are gate signals for two groups of
rectifier devices. The firing angle is controlled using firing control potentiometer.
For Bedford inverter and series inverter, amplifier and isolation section is used. In
which for series inverter select two outputs by switch and for Bedford inverter require
four output signals.
The load value of resistance given in manual and select by switch. Then ‘On’ the
supply otherwise load value is burned see also inductor.
Scientech Technologies Pvt. Ltd.
g.
ltin
su
on
-c
The experiments listed in this manual are only for guidance. The trainees are
expected to apply their skills to modify or correct the circuits wherever required. Pin
diagrams of devices are given in the end of this manual. Use them for proper
connections.
10
pl
hik
w.
ww
ST2712
Experiment 1
Objective :
To study and plot the V-I Characteristics of SCR
Equipments Needed :
Equipments
Quantity
1.
Resistance 470E, ¼ W
1
2.
Resistance 2K2, 2W (on board)
1
3.
SCR TYN 616 (on board)
1
4.
Potentiometer 5K
2
Circuit diagram :
Circuit used to plot characteristics of SCR is shown in figure 1.
on
-c
V-I Characteristics
su
Procedure :
Figure 1
Make circuit connections as shown in the figure 1 using patch cords.
1.
To plot the V -I characteristics proceed as follows.
2.
Rotate both the potentiometer P1 and P2 in fully counter clockwise direction,
connect voltmeter to point ‘6’ & ground to read VG and at point ‘3’ & ground to
read VAK.
3.
Connect ammeter at point ‘1’ & ‘2’ to indicate the current IA and at point ‘4’ &
‘5’ to indicate the gate current IG.
4.
Switch on the power supply.
5.
Vary potentiometer P2 to set the gate current IG to a lower value (5.6mA,
5.7mA, 5.8mA.).
Scientech Technologies Pvt. Ltd.
g.
ltin
•
11
pl
hik
w.
ww
ST2712
6.
Increase anode voltage VA gradually by varying potentiometer P1.
7.
Observe the current IA in the anode circuit, It shows almost zero current at the
initial stage
8.
At certain point of positive anode voltage current IA shows sudden rise in
reading & voltmeter reading falls down to almost zero. This action indicates the
firing of SCR.
9.
If this not happens, repeat the procedure from step 5 for slightly higher value of
gate current IG.
10.
Try the various value of gate current to get the firing of SCR.
11.
Keeping gate current constant observe precisely the firing voltage of SCR and
record it in the observation table.
12.
Also record the anode voltage VA & anode current after firing of the SCR.
13.
Plot the graph of VA versus IA.
Observation Table :
-c
S.
No.
2.
3.
4.
5.
VA
IG = ____mA
IG = ____mA
IG = ____mA
7.
8.
9.
10.
g.
ltin
Scientech Technologies Pvt. Ltd.
su
6.
Voltage
Anode current IA (mA) at constant
value of Gate current
on
1.
Anode
12
pl
hik
w.
ww
ST2712
Experiment 2
Objective :
Study of the Characteristic of UJT and Calculate Interbase Resistance and
Intrinsic Standoff Ratio
Equipments Needed :
Equipments
Quantity
1
1.
Resistance 470E, /4W
2
2.
Potentiometer 5K
2
3.
UJT 2N2646 (on board)
1
Circuit diagram :
Circuit used to plot characteristics of Unijunction transistor is shown in figure 2
on
-c
Emitter Characteristics
Procedure :
Figure 2
Make circuit as shown in the figure 2 using patch cords.
•
To plot the emitter characteristics proceed as follows:
1.
Rotate both the potentiometer P1 and P2 fully in counter clockwise direction.
2.
Connect voltmeter between test point ‘6’ and ground to read VBB and other
between test point ‘3’ and ground to read VE.
3.
Connect ammeter between point ‘1’ and ‘2’ to measure the emitter current IE
and at point ‘4’ and ‘5’ to measure the base current IB.
4.
Switch on the power supply.
5.
Vary potentiometer P2 and set a value of voltage VBB = 5 V.
6.
Increase the emitter voltage VE in steps.
7.
Keep increasing VE until it drops on voltmeter, UJT fires and emitter current
flows rapidly.
Scientech Technologies Pvt. Ltd.
g.
ltin
su
•
13
pl
hik
w.
ww
ST2712
8.
Record the corresponding Emitter current for each value of Emitter voltage VE
in an observation table 1.
9.
Repeat the above procedure from step 8 for VBB = 10 V and 15 V.
10.
Plot the graph of VE versus IE with the help of observation table 1.
Observation Table :
S.
No.
Emitter Emitter current IE (mA) at constant value
voltage of output voltage
VE
VBB = 5V
VBB = 10V
VBB = 15V
1.
2.
3.
Calculations :
1.
Interbase Resistance(Rss)
su
10.
11.
12.
13.
14.
15.
on
-c
4.
5.
6.
7.
8.
9.
RBB = RB1 + RB2
It ranges from 4 to 10 K ohms when Ie = 0.
2.
Intrinsic Stand-off Ratio (η)
η = RB1 (RB1 + RB2) = RBB1 RBB
It ranges from 0.51 to 0.82.
Scientech Technologies Pvt. Ltd.
g.
ltin
It is the sum of resistance between base 1 & base2.
14
pl
hik
w.
ww
ST2712
Experiment 3
Objective :
Study of the Characteristics of MOSFET
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 750E, /4W
1
2.
Resistance 1K, 1W
1
1
3.
Resistance 470E, /4W
1
4.
Zener diode 5V
1
5.
Potentiometer 5K
2
6.
MOSFET IRFZ44N (on board)
1
Circuit diagram :
Circuit used to plot characteristics of MOSFET is shown in figure 3
su
on
-c
Drain Characteristics
Procedure :
Figure 3
Make circuit as shown in the figure 3 using patch cords.
•
To plot drain characteristics proceed as follows:
1.
Connect the circuit on the breadboard as shown in figure
2.
Rotate both the potentiometer P1 and P2 fully in counter clockwise direction.
3.
Connect point ‘1’ and ‘2’ and connect ammeter between point ‘4’ and ‘5’.
4.
Connect one voltmeter between point ‘6’ and ground to measure drain voltage
VDS other voltmeter between point ‘3’ and ground to measure gate voltage VGS.
5.
Switch ‘On’ the power supply.
Scientech Technologies Pvt. Ltd.
g.
ltin
•
15
pl
hik
w.
ww
ST2712
6.
Vary potentiometer P2 and set a value of gate voltage VGS at some constant
value (3 V, 3.1 V, 3.2 V)
7.
Vary the potentiometer P1 so as to increase the value of drain voltage VDS from
zero to 35 V in step and measure the corresponding values of drain current ID
for different constant value gate voltage VGS in an observation table.
8.
Rotate potentiometer P1 fully in counter clockwise direction.
9.
Repeat the procedure from step 6 for different sets of gate voltage VGS.
10.
Plot a curve between drain voltage VDS and drain current ID using suitable scale
with the help of observation table. This curve is the required drain
characteristic.
Observation Table :
S.
No.
Drain Drain current ID (mA) at constant value of
voltage gate voltage
VDS
VGS = 3V
VGS = 3.1V
VGS = 3.2V
g.
ltin
Scientech Technologies Pvt. Ltd.
su
on
-c
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
16
pl
hik
w.
ww
ST2712
Experiment 4
Objective :
Study of the Characteristics of IGBT
Equipments Needed :
Equipment
Quantity
1.
Resistance 25E, 5W
1
2.
Resistance 1K, 1/4W
1
3.
Potentiometer 5K
2
4.
IGBT G4BC20S (on board)
1
Circuit diagram :
Circuit used to plot the characteristics of an IGBT is shown in figure 4.
on
-c
IGBT Characteristics
su
Procedure :
Figure 4
Make circuit as shown in the figure 4 using patch cords.
1.
Rotate the potentiometer P1 fully in clockwise direction and P2 fully in the
counter clockwise direction.
2.
Connect Ammeter between point‘4’ and ‘5’ to measure collector current IC
(mA).
3.
Connect point ‘1’ and ‘2’.
4.
Connect voltmeter between point ‘3’ and ground to measure the Gate voltage
VGE and between point ‘6’ and ground to measure collector voltage VCE.
5.
Switch ‘On’ the power supply.
6.
Vary the potentiometer P1 in counterclockwise direction to set the gate voltage
VGE (between 4.8V and 6.5V).
Scientech Technologies Pvt. Ltd.
g.
ltin
•
17
pl
hik
w.
ww
ST2712
7.
Vary the potentiometer P2 in clockwise direction so as to increase the value of
collector-emitter voltage VCE from 0 to 35V in step and measure the
corresponding values of collector current IC for different constant value of gate
voltage VGE in an Observation Table 1.
8.
Rotate the potentiometer P2 fully in the CCW direction and potentiometer P1
fully in clock wise direction.
9.
Repeat the procedure from step 6 for different sets of gate voltage VGE.
10.
Plot a curve between collector-emitter voltage current (VCE) and Collector
current IC using suitable scale with the help of observation Table 1. This curve is
the required collector characteristic.
Observation table :
S. No.
2.
3.
4.
6.
7.
8.
V
VGE =
V
VGE =
V
10.
11.
12.
13.
15.
16.
Scientech Technologies Pvt. Ltd.
g.
ltin
14.
su
9.
VGE =
on
5.
Collector current IC (mA) at constant
value of gate voltage VGE(volt)
-c
1.
Collector
Voltage
VCE
18
pl
hik
w.
ww
ST2712
Experiment 5
Objective :
Study of the Characteristics of DIAC and plot its V-I Characteristics Curve
Equipments Needed :
Equipment
Quantity
1.
Resistance 1K, 1W (on board)
1
2.
DIAC DB3 (on board)
1
3.
Potentiometer 5K
1
Circuit diagram :
Circuit used to plot different characteristics of DIAC is shown in figure 5.
on
-c
V-I Characteristics
su
Procedure :
Figure 5
Make circuit as shown in the figure 5 using patch cords.
2.
To plot V-I characteristics proceed as follows.
3.
Rotate both the potentiometer P1 fully in counter clockwise direction.
4.
Connect voltmeter across point ‘3’ & ground to read voltage VA.
5.
Connect ammeter between point ‘1’ & ‘2’ to indicate the current IA.
6.
Switch ‘On’ the power supply.
7.
Put the +35 V switch ‘On’.
8.
Vary the potentiometer P1 so as to increase the value of DIAC voltage VA and
measure the corresponding values of current IA in an observation table 1.
9.
Plot the curve between + VA and + IA
Scientech Technologies Pvt. Ltd.
g.
ltin
1.
19
pl
hik
w.
ww
ST2712
10.
Rotate potentiometer P1 fully in counter clockwise direction.
11.
Switch ‘Off’ the power supply.
12.
Put the switch towards -35 V.
13.
Switch ‘On’ the power supply.
14.
Vary the potentiometer P1 so as to increase the value of DIAC voltage VA and
measure the corresponding values of current IA in an observation table.
15.
Plot the curve between –VA and - IA.
Observation Table :
Serial
Number
Diac
Voltage
Va
Diac
Current
Ia
Diac
Voltage
-Va
Diac
Current
-Ia
1.
2.
-c
3.
4.
5.
6.
8.
9.
10.
Scientech Technologies Pvt. Ltd.
g.
ltin
su
on
7.
20
pl
hik
w.
ww
ST2712
Experiment 6
Objective :
Study of the V-I Characteristics of TRIAC
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 470E, /4W
1
2.
Resistance 2K2, 2W (on board)
1
3.
TRIAC BT136 (on board)
1
4.
Potentiometer 5K
2
Circuit diagram :
Circuit used to plot different characteristics of TRIAC is shown in figure 6.
on
-c
V-I Characteristics
1.
2.
3.
4.
6.
7.
8.
9.
10.
Make circuit as shown in the figure 6 using patch cords.
To plot the V-I characteristics proceed as follows:
Rotate both the potentiometer P1 and P2 fully in counter clockwise direction.
Connect voltmeter between point ‘6’ and ground to read VG and between point
‘3’ and ground to read VA.
Connect one ammeter between point ‘1’ & ‘2’ to indicate the current IA and
other between point ‘4’ & ‘5’ to indicates the gate current IG.
Switch on the power supply.
Put the switch towards +35 V.
Vary potentiometer P2 to set the gate current IG to a lower value.
Increase anode voltage VA gradually by varying potentiometer P1.
Observe the current la in the anode circuit, It shows almost zero current at the
initial stage.
Scientech Technologies Pvt. Ltd.
g.
ltin
5.
Figure 6
su
Procedure :
21
pl
hik
w.
ww
ST2712
11.
If this not happens, repeat the procedure from step 8 slight higher value of gate
current IG.
12.
Try the various value of gate current to get the firing of TRIAC.
13.
Also record the anode voltage VA & anode current after firing of the TRIAC in
table 1.
14.
Rotate potentiometer P1 fully in CCW direction.
15.
Put the switch towards -35 V and repeat from step 6 and note down the reading
in observation table 2.
16.
Plot the graph of -VA versus -IA.
Observation Table 1 :
S.
No.
Anode Anode current Ia (mA) at constant value of
voltage Gate current (when switch is to words 35V)
Va
Ig = __ mA Ig = __ mA
Ig = __ mA
Observation Table 2 :
su
S.
No.
on
-c
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Anode Anode current Ia (mA) at constant value of
voltage Gate current (when switch is to words -35V)
Va
Ig = __ mA Ig = __ mA
Ig = __ mA
Scientech Technologies Pvt. Ltd.
g.
ltin
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
22
pl
hik
w.
ww
ST2712
Experiment 7
Objective :
Study of the Characteristics of PUT
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 2K5, /4W
1
2.
Resistance 10K, 1/4W
1
3.
Resistance 2K2, 2W (on board)
1
4.
PUT 2N 6027 (on board)
1
5.
Potentiometer 5K
1
6.
Potentiometer 10K
1
Circuit diagram :
Circuit used to plot the characteristics of a PUT is shown in figure 7.
su
on
-c
V-I Characteristics
Procedure :
Figure 7
Make circuit as shown in the figure 7 using patch cords.
•
To plot characteristics proceed as follows:
1.
Rotate both the potentiometers P1 and P2 fully in the clockwise direction.
2.
Connect Ammeter between point ‘4’ and ‘5’ to measure gate current IG (mA)
and between point ‘1’ and ‘2’ to measure anode current IA (mA).
3.
Connect voltmeter between point ‘3’ and ground to measure the anode voltage
(VA).
Scientech Technologies Pvt. Ltd.
g.
ltin
•
23
pl
hik
w.
ww
ST2712
4.
Connect voltmeter between point ‘6’ and ground to measure the Gate voltage
VG.
5.
Switch ‘On’ the power supply.
6.
Vary the potentiometer P2 to set a value of gate voltage VG at some constant
value (2.0V, 5.0V, 10V).
7.
Vary the potentiometer P1 so as to increase the value of anode voltage VA from
0 to 15V in step and measure the corresponding values of anode current IA for
different constant value of gate voltage VG in an Observation Table 1.
8.
Rotate the potentiometer P2 fully in the CCW direction.
9.
Repeat the procedure from step 6 for different sets of gate voltage VG.
10.
Plot a curve between anode voltage (VA) and anode current IA using suitable
scale with the help of observation Table 1. This curve is required V-I
characteristic.
Observation Table :
-c
S.
No.
Anode voltage VA, anode current IA and gate current IG at different
gate voltage
VG = 2.0V
VA
IA
IG
VA
VG = 5.0V
IA
VG = 10.0V
IG
VA
IA
IG
g.
ltin
su
on
Scientech Technologies Pvt. Ltd.
24
pl
hik
w.
ww
ST2712
Experiment 8
Objective :
Study of Class B Commutation Circuit
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 1K, /4W
1
2.
Electrolytic Capacitor 2.2µF/25V
1
3.
Inductor 10mH (on board)
1
4.
SCR 2P4M (on board)
1
Circuit diagram :
The circuit diagram of class B commutation circuits as follows :
on
-c
Class-B Commutation Circuit
Procedure :
Figure 8
Connect circuit as shown above figure 8.
2.
Connect Gate of SCR to G1 signal.
3.
Switch on the power supply.
4.
Connect oscilloscope across SCR and observe the waveform.
5.
Connect oscilloscope across load resistance and observe waveform.
g.
ltin
Scientech Technologies Pvt. Ltd.
su
1.
25
pl
hik
w.
ww
ST2712
on
-c
Waveforms of Class-B Commutation
Figure 9
g.
ltin
su
Scientech Technologies Pvt. Ltd.
26
pl
hik
w.
ww
ST2712
Experiment 9
Objective :
Study of Class C Commutation Circuit
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 2K2, /4W
2
2.
MET. CAP. 0.1MFD (on board)
1
3.
SCR TYN616
2
Circuit diagram :
The circuit diagram of class C commutation circuits is as follows:
on
-c
Class C Commutation Circuit
Procedure :
Figure 10
Connect circuit as shown above figure 10.
2.
Connect G1 & G2 signal to gate of SCR.
3.
Switch ‘On’ the power supply.
4.
Connect oscilloscope across SCR and observe waveform.
5.
Connect oscilloscope across load resistance and observe waveform.
g.
ltin
Scientech Technologies Pvt. Ltd.
su
1.
27
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Waveforms of Class C Commutation
Figure 11
Scientech Technologies Pvt. Ltd.
28
pl
hik
w.
ww
ST2712
Experiment 10
Objective :
Study of Class D Commutation Circuit
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 511E, /4W
1
2.
Met. Cap 0.33 MFD (on board)
1
3.
SCR 2P4M (on board)
2
4.
Inductor 68mH (on board)
1
5.
Diode 1N4007 (on board)
1
Circuit diagram :
The circuit diagram of class D commutation circuits is as follows :
on
-c
Procedure :
su
D Commutation Circuit
Make circuit as shown in the figure 12.
2.
Connect G1 & G2 signal to gate of SCR1 & SCR2.
3.
Switch ‘On’ the power supply.
4.
Connect oscilloscope across SCR1& SCR2 and observe waveforms.
Scientech Technologies Pvt. Ltd.
g.
ltin
1.
Figure 12
29
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Waveforms of Class-D Commutation
Figure 13
Scientech Technologies Pvt. Ltd.
30
pl
hik
w.
ww
ST2712
Experiment 11
Objective :
Study of Class-F Commutation Circuit
Equipments Needed :
Equipment
Quantity
1.
Resistance 1K,10W (on board)
1
2.
SCR 2P4M (on board)
1
Circuit diagram :
The circuit diagram of class D commutation circuits is as follows:
-c
Class D Commutation Circuit
on
Procedure :
Figure 14
Connect circuit as shown above figure 14 using patch cords.
2.
Connect GR1 signal to gate of SCR.
3.
Switch ‘On’ the power supply.
4.
Vary the firing control pot and observe waveform across load.
5.
Vary the firing control pot and observe waveform across SCR.
g.
ltin
Scientech Technologies Pvt. Ltd.
su
1.
31
pl
hik
w.
ww
ST2712
on
-c
Waveform of Class F Commutation
Figure 15
g.
ltin
su
Scientech Technologies Pvt. Ltd.
32
pl
hik
w.
ww
ST2712
Experiment 12
Objective :
Study of the Resistor Triggering Circuit
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 1K, /4W
1
2.
Resistance 511E, 1/4W
2
3.
Potentiometer 1M (on board)
1
4.
SCR 2P4M (on board)
1
5.
Diode 1N4007 (on board)
1
Circuit diagram :
The circuit diagram for SCR Triggering circuits is as follows:
on
-c
Resistance Triggering Circuit
Procedure :
Figure 16
Make circuit as shown in the figure 16 using patch cords
2.
Rotate the potentiometer P1 fully in the CW (clockwise direction).
3.
Switch ‘On’ the power supply.
4.
Connect the oscilloscope CHI across the load and observe the Phase angle and
voltage.
5.
Now, connect the oscilloscope probe across the thyristor and observe the
waveform.
6.
Vary the potentiometer slowly; you can see the phase angle variation.
7.
Repeat the experiment from step 5 for various angles and plot the graphs by
Scientech Technologies Pvt. Ltd.
g.
ltin
T = (α X 10ms) / 180
su
1.
33
pl
hik
w.
ww
ST2712
Observation Table 1 :
S.No.
Load
voltage(V)
Phase Angle
(α)
1.
2.
3.
4.
5.
6.
su
on
-c
Waveforms of R Firing Circuit
g.
ltin
Scientech Technologies Pvt. Ltd.
Figure 17
34
pl
hik
w.
ww
ST2712
Experiments 13
Objective :
Study of the Resistor-Capacitor Triggering Circuit (Half Wave)
Equipments Needed :
Equipment
Quantity
1.
Resistance 1K, 1/4W
1
2.
Potentiometer 1M (on board)
1
3.
SCR 2P4M (on board)
1
4.
Diode 1N4007 (on board )
2
5.
Met. Cap. 0.1 MFD(on board)
1
Circuit diagram :
The circuit diagram for SCR Triggering circuits is as follows:
on
-c
Resistor-Capacitor Triggering Circuit
su
Procedure :
Figure 18
Make circuit as shown in the figure 18 using patch cords.
2.
Rotate the potentiometers P fully in the CCW (Anticlockwise direction).
3.
Switch ‘On’ the power supply.
4.
Connect the oscilloscope probe between the load test point TP3 and TP4 and
observe the Phase angle and voltage.
5.
Now, connect the oscilloscope probe across the thyristor and observe the
waveform.
6.
Vary the potentiometer slowly; you can see the phase angle variation.
7.
Repeat the experiment from step 5 for various angles and plot the graphs.
T = (α X 10ms) / 180
Scientech Technologies Pvt. Ltd.
g.
ltin
1.
35
pl
hik
w.
ww
ST2712
Observation Table :
S.
No.
Load voltage(V) Phase Angle (α)
1.
2.
3.
4.
5.
6.
on
-c
Waveforms of RC Half Wave Firing Circuit
Figure 19
g.
ltin
su
Scientech Technologies Pvt. Ltd.
36
pl
hik
w.
ww
ST2712
Experiment 14
Objective :
Study of the Resistor-Capacitor Triggering Circuit (Full Wave)
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 511E, /4W
1
2.
Resistance 1K, 1W (on board)
1
3.
SCR 2P4M (on board)
1
4.
POT 1M (on board)
1
5.
Ele. Cap 1MFD (on board)
1
6.
Diode 1N4007
4
Circuit diagram :
The circuit diagram for SCR Triggering circuits is as follows:
su
on
-c
Resistor - Capacitor Triggering Circuit
Procedure :
Figure 20
Make circuit as shown in the figure 20 using patch cords.
2.
Rotate the potentiometers P fully in the CW (clockwise direction).
3.
Switch ‘On’ the power supply.
4.
Connect the oscilloscope probe between the load test point TP5 and TP6 and
observe the Phase angle and voltage.
5.
Now, connect the oscilloscope probe across the thyristor and observe the
waveform.
Scientech Technologies Pvt. Ltd.
g.
ltin
1.
37
pl
hik
w.
ww
ST2712
6.
Vary the potentiometer slowly; you can see the phase angle variation.
7.
Repeat the experiment from step 5 for various angles and plot the graphs.
T = (α X 10ms) / 180
Observation Table :
S. No.
Load voltage (V)
Phase Angle (α)
1.
2.
3.
4.
5.
6.
g.
ltin
su
on
-c
Waveform of RC Full Wave Firing Circuit
Figure 21
Scientech Technologies Pvt. Ltd.
38
pl
hik
w.
ww
ST2712
Experiment 15
Objective :
Study of the triggering of SCR using UJT
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 47K, /4W
1
2.
Resistance 47E, 1/4W
1
3.
Resistance 100E, 2W
1
4.
Resistance 220E, 1/4W
1
5.
Potentiometer 5K
2
6.
Ele. cap 1MFD (on board)
1
7.
UJT 2N2646 (on board)
1
8.
SCR TYN 616(on board)
1
-c
Circuit diagram :
The circuit diagram for Triggering of SCR using UJT is shown in figure 22.
su
on
g.
ltin
Triggering SCR using UJT
Figure 22
Scientech Technologies Pvt. Ltd.
39
pl
hik
w.
ww
ST2712
Procedure :
Make circuit as shown in the figure 22 using patch cords.
2.
Connect Ammeter between points‘3’ and ‘4’ to measure Anode-cathode current
IAK (mA).
3.
Connect Ammeter between points ‘1’ and ‘2’ to measure the gate Current IG
(mA).
4.
Connect voltmeter between point ‘5’ and ground to measure the anode-cathode
voltage VAK.
5.
Rotate the potentiometer P1 fully in clockwise direction and P2 fully in the CCW
(counter clockwise direction).
6.
Switch ‘On’ the power supply.
7.
Vary the potentiometer P2 in clockwise direction so as to increase the anode to
cathode voltage. Set this voltage above 11V.
8.
Vary the potentiometer P1 in counterclockwise direction so as to increase the
value of gate current in step and measure the corresponding values of anode to
cathode current IAK in an observation table 1.
9.
Initially there will not be any current flow across the SCR, while varying the
gate current the ammeter connected at point ‘c’ and‘d’ suddenly increases and
the voltmeter connected at point ‘e’ and ground will suddenly decrease. This
shows that the SCR is triggered.
10.
Now vary the POT1, there will not be any effect in the anode –cathode voltage
and current of SCR.
11.
To repeat the experiment switch off the power supply and follow the above
procedure from step 6.
su
Observation table :
on
-c
1.
Set VAK = +12V
S.
No.
Gate current
IG (mA)
Anode to cathode
voltage VAK (V)
g.
ltin
Scientech Technologies Pvt. Ltd.
Anode to cathode
current IAK (mA)
40
pl
hik
w.
ww
ST2712
Experiment 16
Objective :
Study of the Triggering of SCR using 555 IC
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 1K, /4W
1
2.
Resistance 100E, 2W
1
1
Resistance 5K, /4W
1
4.
IC 555 timer
1
5.
Capacitor 0.01MFD
1
6.
Ele. Cap 1MFD (on board)
1
7.
Diode 1N4007 (on board)
1
8.
SCR TYN 616(on board)
1
9.
Potentiometer 5K
2
-c
3.
Circuit diagram :
The circuit diagram for Triggering of SCR using 555 IC is as follows:
g.
ltin
su
on
Triggering of SCR using 555 IC
Figure 23
Scientech Technologies Pvt. Ltd.
41
pl
hik
w.
ww
ST2712
Procedure :
Make circuit as shown in the figure 23 using patch cords.
2.
Connect Ammeter between points ‘3’ and ‘4’ to measure Anode-cathode
current IAK (mA).
3.
Connect Ammeter between points ‘1’ and ‘2’ to measure the gate Current IG
(mA).
4.
Connect voltmeter between point ‘5’ and ground to measure the anodecathode voltage VAK.
5.
Rotate the potentiometer P1 fully in clockwise direction and P2 fully in the
CCW (counter clockwise direction).
6.
Switch ‘On’ the power supply.
7.
Vary the potentiometer P2 in clockwise direction so as to increase the anode to
cathode voltage. Set this voltage above 11V.
8.
Vary the potentiometer P1 in counterclockwise direction so as to increase the
value of gate current in step and measure the corresponding values of anode to
cathode current IAK in an Observation table 1.
9.
Initially there will not be any current flow across the SCR while varying the
gate current the ammeter connected at point ‘3’ and ‘4’ suddenly increases and
the voltmeter connected at point ‘5’ and ground will suddenly decrease. This
shows that the SCR is triggered.
10.
Now vary the POT1, there will not be any effect in the anode –cathode voltage
and current of SCR.
11.
To repeat the experiment switch off the power supply and follow the
procedure from step 6.
Observation Table :
su
on
-c
1.
Set VAK = +12V
S.
No.
Gate current
IG (mA)
Anode to cathode
voltage VAK (V)
g.
ltin
Scientech Technologies Pvt. Ltd.
Anode to cathode
current IAK (mA)
42
pl
hik
w.
ww
ST2712
Experiment 17
Objective :
Study of the Triggering of SCR using Op-Amp 741 IC
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 10K, /4W
3
2.
Resistance 120E, 5W (on board)
1
3.
Zener 10V
1
4.
SCR TYN 616 (on board)
1
5.
Potentiometer 5K
2
6.
IC lm741
1
7.
Met cap 0.047MFD
1
Circuit diagram :
g.
ltin
su
on
-c
The circuit diagram for Triggering of SCR using 74121 IC is shown in below figure
24.
Triggering of SCR using Op-Amp 555 IC
Figure 24
Scientech Technologies Pvt. Ltd.
43
pl
hik
w.
ww
ST2712
Procedure :
Make circuit as shown in the figure 24 using patch cords.
2.
Connect Ammeter between point ‘3’ and ‘4’ to measure Anode-cathode current
IAK (mA).
3.
Connect Ammeter between point ‘1’ and ‘2’ to measure the gate
Current IG (mA).
4.
Connect voltmeter between point ‘5’ and ground to measure the anode-cathode
voltage VAK.
5.
Rotate the potentiometer P1 and P2 fully in the clockwise direction.
6.
Switch ‘On’ the power supply.
7.
Vary the potentiometer P2 in anti clockwise direction so as to increase the anode
to cathode voltage. Set this voltage above 11V.
8.
Vary the potentiometer P1 in clockwise direction so as to increase the value of
gate current in step and measure the corresponding values of anode to cathode
current IAK in an Observation Table 1.
9.
Initially there will not be any current flow across the SCR while varying the gate
current the ammeter connected at point ‘3’ and ‘4’ suddenly increases and the
voltmeter connected at point ‘5’ and ground will suddenly decrease. This shows
that the SCR is triggered.
10.
Now vary the POT1, there will not be any effect in the anode–cathode voltage
and current of SCR.
11.
To repeat the experiment switch off the power supply and follow the procedure
from step 4.
Scientech Technologies Pvt. Ltd.
g.
ltin
su
on
-c
1.
44
pl
hik
w.
ww
ST2712
Experiment 18
Objective :
Study of the Ramp and Pedestal Triggering using Anti-Parallel SCR in AC Load
Equipments Needed :
Equipment
Quantity
1.
Resistance 220E, 2W
1
2.
Resistance 20K, 1/4W
1
1
Resistance 200E, /4W
1
4.
Resistance 1K, 1W (on board)
1
5.
Ele. Cap 1MFD (on board)
1
6.
Diode 1N4007 (on board)
5
7.
Zener 9V
1
8.
Potentiometer 10K
1
9.
UJT 2N2646 (on board)
1
10.
SCR 2P4M (on board)
2
11.
Pulse transformer 1:1:1 (on board)
1
-c
3.
Circuit diagram :
on
The circuit diagram of basic anti-parallel SCR in AC load is shown in the below
figure.
g.
ltin
su
Ramp & Pedestal Triggering using Anti - Parallel SCR
Figure 25
Scientech Technologies Pvt. Ltd.
45
pl
hik
w.
ww
ST2712
Procedure :
1.
Make circuit as shown in the figure 25 using patch cords.
2.
Rotate the potentiometer P1 fully in clockwise direction.
3.
Connect the circuit as shown in the figure above using 2mm patch cords.
4.
Switch ‘On’ the power supply.
5.
Connect the oscilloscope and observe the output waveform across the Load
resistor.
6.
Set the firing angle at 30º, 60º, 90º, 120º, and 150º by varying the pot P1 and
note the reading of output voltage. Angle in time convert using T = (α X 10ms) /
180 .
7.
Observe the output waveform across load and across SCRs at firing angle is 90º
and Plot the waveforms.
Observation Table :
-c
S.
No.
Input
AC voltage
(Vrms)
Output across AC load
circuit
Output
voltage
(Vrms)
Scientech Technologies Pvt. Ltd.
g.
ltin
su
on
Firing angle
(Degree)
46
pl
hik
w.
ww
ST2712
su
on
-c
Waveforms of Ramp and Pedestal Circuit
g.
ltin
Scientech Technologies Pvt. Ltd.
Figure 26
47
pl
hik
w.
ww
ST2712
Experiment 19
Objective :
Study of the UJT Relaxation Oscillator
Equipments Needed :
Apparatus
Quantity
1
1.
Resistance 12K1, /4W
1
2.
Resistance 220E, 1/4W
1
1
3.
Resistance 100E, /4W
1
4.
Diode 1N4007
1
5.
Met. Cap. 0.1MFD (on board)
1
6.
UJT 2N2646 (on board)
1
Circuit diagram :
Circuit diagram of UJT relaxation oscillator is given below :
g.
ltin
su
on
-c
UJJ Relaxation Oscillator
Figure 27
Procedure :
1.
Make circuit as shown in the figure 27 using patch cords.
2.
Rotate the potentiometer P1 fully in clockwise direction.
3.
Switch ‘On’ the power supply.
Scientech Technologies Pvt. Ltd.
48
pl
hik
w.
ww
ST2712
4.
Connect the oscilloscope CHI between output and ground and CHII between
TP1 and ground and observe the waveform of pulse output and RC time
constant.
5.
Vary the potentiometer P1 in clockwise direction so as to increase the frequency
of the output.
6.
Sketch the waveforms on the paper.
Observation Table :
S.
No.
Minimum
Frequency (Hz)
Maximum
Frequency (Hz)
g.
ltin
su
on
-c
Waveform of UJT Relaxation Oscillator
Figure 28
Scientech Technologies Pvt. Ltd.
49
pl
hik
w.
ww
ST2712
Experiment 20
Objective :
Study of the Voltage Commutated Chopper
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 511E, /4W
1
2.
Met. Cap. 0.33MFD (on board)
1
3.
Inductor 68mH(on board)
1
4.
Inductor 10mH (on board)
1
5.
SCR 2P4M (on board)
2
6.
Diode 1N4007 (on board)
2
Circuit diagram :
Circuit diagram of voltage commutated chopper is given below :
su
on
-c
Voltage Commutated Chopper
Procedure :
Figure 29
Make circuit connection as shown above figure 29.
2.
Connect G1& G2 to the gate of SCR1 and SCR2.
3.
Switch ‘On’ the power supply.
4.
Vary the PWM Potentiometer in fully clock wise direction.
5.
Vary the frequency pot and observe the output across load and across SCR1&
SCR2.
6.
Sketch the waveforms on the paper.
Scientech Technologies Pvt. Ltd.
g.
ltin
1.
50
pl
hik
w.
ww
ST2712
Observation Table :
S.
No.
Frequency (Hz)
Output voltage
(V)
g.
ltin
su
on
-c
Waveforms of Voltage Commutated Chopper
Figure 30
Scientech Technologies Pvt. Ltd.
51
pl
hik
w.
ww
ST2712
Experiment 21
Objective :
Study of the Bedford Inverter
Equipments Needed :
Equipment
Quantity
1
1.
Resistance 30K, /4W
1
2.
Met. Cap 1MFD
4
3.
SCR 2P4M (on board)
4
4.
Diode 1N4007 (on board)
4
Circuit diagram :
Circuit diagram of Bedford inverter is given below :
su
on
-c
SCR1, SCR2, SCR3, SCR4 =2P4M
C1, C2, C3, C4, = MET. 1µF/25V
D1, D2, D3, D4 = 1N4007
g.
ltin
Bedford Inverter
Figure 31
Scientech Technologies Pvt. Ltd.
52
pl
hik
w.
ww
ST2712
Procedure :
1.
Make circuit connection as shown above figure 31
2.
Connect G1& G2 to the gate of SCR1 and SCR2.
3.
Switch ‘On’ the power supply.
4.
Rotates the PWM Potentiometer in fully clock wise direction.
5.
Vary the frequency pot and observe the output across load and across SCR1&
SCR2.
6.
Sketch the waveforms on the paper.
Observation Table :
S.
No.
Frequency
(Hz)
Output voltage
(V)
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
53
pl
hik
w.
ww
ST2712
Experiment 22
Objective :
Study of the Single Phase PWM Inverter using MOSFET and IGBT
Equipments Needed :
Equipment
Quantity
1.
MOSFET IRFZ 44N
4
2.
IGBT G4BC20S
4
3.
1
Resistance 1K, /4W
1
4.
Tiny toggle switch 1P-2W
1
Circuit diagram :
on
-c
Figure 32
g.
ltin
su
Single Phase PWM Inverter
Figure 33
Procedure :
1.
Make the circuit shown in the figure 32.
2.
Rotate the frequency potentiometer in fully anticlockwise direction and PWM
pot in fully clockwise direction.
Scientech Technologies Pvt. Ltd.
54
pl
hik
w.
ww
ST2712
3.
Switch ‘On’ the power supply.
4.
Vary the frequency pot and observe waveform across load on oscilloscope.
5.
Set the maximum frequency by frequency pot.
6.
Vary PWM potentiometer and observe output waveform across load and note
the readings of pulse width and corresponding output AC (rms) voltage across
load.
7.
Switch off the power supply.
8.
Make a circuit as shown in the figure 33. And repeat from step 2.
9.
Sketch the waveforms of gate pulse and output pulse across the load.
Observation table :
S.
No.
Pulse width
(ms)
AC output voltage
across load
(MOSFET)
(volts)
AC output voltage
across load
(IGBT)
(volts)
g.
ltin
su
on
-c
Waveform of PWM Inverter
Figure 34
Scientech Technologies Pvt. Ltd.
55
pl
hik
w.
ww
ST2712
Experiment 23
Objective :
Study of the Half – Wave Controlled Rectifier with Resistive Load
Equipments Needed :
Equipment
Quantity
1.
SCR 2P4M (on board)
1
2.
Resistance 1K, 10W (on board)
1
3.
Resistance 270E, 5W (on board) 1
4.
Inductor 68mH (on board)
2
Circuit diagram :
The circuit diagram of basic half-wave controlled rectifier is shown in the below
figure 35
on
-c
Scientech Technologies Pvt. Ltd.
Figure 35
g.
ltin
su
Half – Wave Controlled Rectifier
56
pl
hik
w.
ww
ST2712
Procedure :
Make the circuit shown in the figure 35.
1.
Rotate the firing control pot in full clockwise direction.
2.
Switch ‘On’ the power.
3.
Measure the ac voltage (Vrms) by voltmeter between point 0V-15V and
calculate Em by Em =1.414 X Vrms.
4.
Switch ‘Off’ the power.
5.
Connect the circuit of half-wave rectifier as shown figure 36.
6.
Switch ‘On’ the power.
7.
Connect the oscilloscope and voltmeter across the load.
8.
Vary the firing control pot and set on 30º, 60º, 90º, 120º and 150º firing angles
using T = (α X 10ms) / 180.
9.
Observe the output waveforms and note the readings of voltage across load on
different firing angles.
10.
Observe the waveform across the SCR1 when firing angle is 90º.
11.
Calculate the average load IDC current and power PDC from measured load
voltage Vo.
12.
Plot the input signal, gate pulse, and drop signal across SCR and output
waveforms when firing angle is 90º.
Scientech Technologies Pvt. Ltd.
g.
ltin
su
on
-c
•
57
pl
pl
S.
No.
In
(VRMS)
In
(VM)
Input AC Voltage
Observation Table :
g.
ltin
Scientech Technologies Pvt. Ltd.
In
Deg.
In
Time
(ms)
Firing Angle
su
Average Output Voltage
Across Load
Measured
Voltage
(Vo)
Calculated
Voltage
(VDC)
on
Measured
(Io)
Vo / RL
Calculated
(IDC)
VDC / RL
Average Load Current
(IDC)
-c
Measured
Po
Vo X Io
Calculated
(PDC)
VDC X IDC
Average Output Power
hik
w.
ww
ST2712
58
hik
w.
ww
ST2712
su
on
-c
Waveform of Half Wave Rectifier with Resistive Load
g.
ltin
Scientech Technologies Pvt. Ltd.
Figure 36
59
pl
hik
w.
ww
ST2712
su
on
-c
Scientech Technologies Pvt. Ltd.
g.
ltin
Waveform of Half Wave Rectifier with Resistive- Inductive Load
Figure 37
60
pl
hik
w.
ww
ST2712
Experiment 24
Objective :
Study of the Full – Wave Controlled Rectifier (mid-point configuration) with
Resistive Load.
Equipments Needed :
Equipment
Quantity
1.
SCR 2P4M (on board)
2
2.
Resistance 1K, 10W (on board)
1
3.
Resistance 270E, 5W (on board)
1
4.
Inductor 68mH (on board)
2
Circuit diagram :
The circuit diagram of basic full – wave controlled rectifier (mid- point configuration)
is shown in the below figure 38
su
on
-c
Full – Wave Controlled Rectifier
g.
ltin
Scientech Technologies Pvt. Ltd.
Figure 38
61
pl
hik
w.
ww
ST2712
Procedure :
Make connections according to figure 38.
1.
Rotate the firing control Potentiometer in full clockwise direction.
2.
Switch ‘On’ the power.
3.
Measure the ac voltage (Vrms) by voltmeter between point 0V-18V and
calculate Em by Em =1.414 X Vrms.
4.
Switch ‘Off’ the power.
5.
Connect the circuit of full-wave controlled rectifier (mid-point configuration) as
shown figure 9 using 2 mm patch cords.
6.
Switch ‘On’ the power.
7.
Connect the oscilloscope and voltmeter across the load.
8.
Vary the firing control pot and set on 30º, 60º, 90º, 120º and 150º firing angles
using T = (α X 10ms) / 180.
9.
Observe the output waveforms and note the readings of voltage across load on
different firing angle.
10.
Connect the oscilloscope one by one across SCR1 and SCR2 and observe the
waveform when firing angle is 90º.
11.
Calculate the average load IDC current and power PDC from measured load
voltage Vo.
12.
Plot the input signal, gate pulse, and drop signal across SCR and output
waveforms when firing angle is 90º.
Scientech Technologies Pvt. Ltd.
g.
ltin
su
on
-c
•
62
pl
pl
S.
No.
In
(VRMS)
In
(VM)
Input AC Voltage
Observation Table :
g.
ltin
Scientech Technologies Pvt. Ltd.
In
Deg.
In
Time
(ms)
Firing Angle
su
Average Output Voltage
Across Load
Measured
Voltage
(Vo)
Calculated
Voltage
(VDC)
on
Measured
(Io)
Vo / RL
Calculated
(IDC)
VDC / RL
Average Load Current
(IDC)
-c
Measured
Po
Vo X Io
Calculated
(PDC)
VDC X IDC
Average Output Power
hik
w.
ww
ST2712
63
hik
w.
ww
ST2712
su
on
-c
Waveform of Full Wave Rectifier (mid-point) with Resistive Load
g.
ltin
Scientech Technologies Pvt. Ltd.
Figure 39
64
pl
hik
w.
ww
ST2712
su
on
-c
Waveform of Full Wave Rectifier (mid-point) with Resistive-Inductive Load
g.
ltin
Scientech Technologies Pvt. Ltd.
Figure 40
65
pl
hik
w.
ww
ST2712
Experiment 25
Objective :
Study of the Fully Controlled Bridge Rectifier with Resistive Load
Equipments Needed :
Equipment
Quantity
1.
SCR 2P4M (on board)
4
2.
Resistance 1K, 10W (on board)
1
3.
Resistance 270E, 5W (on board)
1
4.
Inductor 68mH (on board)
2
Circuit diagram :
The circuit diagram of basic fully controlled bridge rectifier is shown in the below
figure 41
su
on
-c
Controlled Bridge Rectifier
g.
ltin
Scientech Technologies Pvt. Ltd.
Figure 41
66
pl
hik
w.
ww
ST2712
Procedure :
Rotate the firing control Potentiometer in full clockwise direction.
2.
Switch ‘On’ the power.
3.
Measure the ac voltage (Vrms) by voltmeter between point 0V-15V and
calculate Em by Em =1.414 X Vrms.
4.
Switch ‘Off’ the power.
5.
Connect the circuit of fully-controlled bridge rectifier as shown figure 42 using
2 mm patch cords.
6.
Switch ‘On’ the power.
7.
Connect the oscilloscope and voltmeter across the load.
8.
Vary the firing control pot and set on 30º, 60º, 90º, 120º and 150º firing angles
using T = (α X 10ms) / 180 .
9.
Observe the output waveforms and note the readings of voltage across load on
different firing angle.
10.
Connect the oscilloscope one by one across SCR1, SCR2, and SCR3 & SCR4
and observe the waveforms when firing angle is 90º respectively.
11.
Calculate the average load IDC current and power PDC from measured load
voltage Vo.
12.
Plot the input signal, gate pulse, and drop signal across SCR and output
waveforms when firing angle is 90º with resistive and resistive-inductive load.
Scientech Technologies Pvt. Ltd.
g.
ltin
su
on
-c
1.
67
pl
pl
S.
No.
In
(VRMS)
In
(VM)
Input AC Voltage
g.
ltin
Scientech Technologies Pvt. Ltd.
In
Deg.
In
Time
(ms)
Firing Angle
su
Average Output Voltage
Across Load
Measured
Voltage
(Vo)
Calculated
Voltage
(VDC)
on
Measured
(Io)
Vo / RL
Calculated
(IDC)
VDC / RL
Average Load Current
(IDC)
-c
Measured
Po
Vo X Io
Calculated
(PDC)
VDC X IDC
Average Output Power
hik
w.
ww
ST2712
68
hik
w.
ww
ST2712
-c
on
Waveform of Full Wave Bridge Rectifier with Resistive Load
Figure 42
g.
ltin
su
Scientech Technologies Pvt. Ltd.
69
pl
hik
w.
ww
ST2712
su
on
-c
Waveform of Full Wave Bridge Rectifier with Resistive - Inductive Load
g.
ltin
Scientech Technologies Pvt. Ltd.
Figure 43
70
pl
hik
w.
ww
ST2712
Data Sheets
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
71
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
72
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
73
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
74
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
75
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
76
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
77
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
78
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
79
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
80
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
81
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
82
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
83
pl
hik
w.
ww
ST2712
g.
ltin
su
on
-c
Scientech Technologies Pvt. Ltd.
84
pl
hik
w.
ww
ST2712
Warranty
1.
We guarantee the product against all manufacturing defects for 24 months from
the date of sale by us or through our dealers. Consumables like dry cell etc. are
not covered under warranty.
2.
The guarantee will become void, if
a)
The product is not operated as per the instruction given in the operating
manual.
b)
The agreed payment terms and other conditions of sale are not followed.
c)
The customer resells the instrument to another party.
d)
Any attempt is made to service and modify the instrument.
3.
The non-working of the product is to be communicated to us immediately giving
full details of the complaints and defects noticed specifically mentioning the
type, serial number of the product and date of purchase etc.
4.
The repair work will be carried out, provided the product is dispatched securely
packed and insured. The transportation charges shall be borne by the customer.
on
-c
List of Accessories
su
Bread Boards ........................................................................................... 2 Nos.
2.
Connecting Wires .................................................................................. 20 Nos.
3.
2mm to 1mm Patch Cords ..................................................................... 15 Nos.
4.
2mm Patch Cords (Red) .......................................................................... 4 Nos.
5.
2mm Patch Cords (Black)........................................................................ .4 Nos.
6.
2mm Patch Cords (Blue) ....................................................................... 12 Nos.
7.
Mains Cord ................................................................................................1 No.
8.
e-Manual....................................................................................................1 No.
g.
ltin
1.
Updated 20-04-2009
Scientech Technologies Pvt. Ltd.
85
pl
hik
w.
ww
ST2712
Scientech Technologies Pvt. Ltd.
g.
ltin
su
on
-c
List of other Trainers available from us are :
Model
Name
PE01
UJT Characteristics
PE02
MOSFET Characteristics
PE03
SCR Characteristics
PE04
TRIAC Characteristics
PE05
DIAC Characteristics
PE06
IGBT Characteristics
PE07
PUT Characteristics
PE10
SCR Triggering (R, RC Full wave, RC Half wave)
PE11
SCR Triggering (UJT)
PE12
SCR Triggering (IC555)
PE13
SCR Triggering (IC74121)
PE14
Ramp and Pedestal Triggering
PE15
SCR Triggering (IC741)
PE16
SCR Triggering (PUT)
PE40
SCR Lamp Flasher
PE41
SCR Alarm Circuit
PE42
Series Inverter
PE43
UJT Relaxation Oscillator
PE44
Single Phase PWM Inverter
ST2701
IGBT Characteristics
ST2702
SCR Triggering (R, RC Half wave, RC Full wave)
ST2703
SCR Triggering Techniques
ST2704
Triggering of SCR using 74121 IC
ST2705
SCR Lamp Flasher
ST2706
SCR Alarm Circuit
ST2707
Series Inverter
ST2708
Single Phase Controlled Rectifier (with Ramp Comparator Firing
Scheme)
ST2709
Single Phase Controlled Rectifier (Cosine Firing Scheme)
ST2710
Single Phase Converter Firing Techniques (by TCA 785IC and
Triangular Comparator)
ST2711
Lamp Dimmer
ST2712
Electronics Power Lab
ST2713
Single Phase Cyclo-Converter
ST2714
Speed Control of Universal Motor using SCR
ST2715
Speed Control of AC Motor using TRIAC
ST2716
Microcontroller Based Firing Circuit for Controlled Rectifier
ST2717
SCR Commutation Circuits
ST2718
Bedford & Parallel Inverter
ST2719
Step-Up Chopper
ST2720
Single Phase Bridge Inverter
ST2722
Step-Down Chopper
ST2723
AC Chopper
86
pl