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Power Electronics Lab

ST2712

Operating Manual

Ver 1.1

An ISO 9001 : 2000 company

94-101, Electronic Complex Pardesipura,

Indore- 452010, INDIA

Tel : 91-731- 2570301/02, 4211100

Fax: 91- 731- 2555643

E-mail : [email protected]

Website : www.scientech.bz

Toll free No. : 1800-103-5050

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ST2712

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ST2712

Power Electronics Lab

ST2712

Table of Contents

1.

2.

3.

4.

Safety Instructions

Introduction

Features

Technical Specifications

5.

6.

Functions of Various Blocks

Operating Instructions & Panel Control Description

7.

Experiments

Experiment 1

Study of the V-I Characteristics of SCR

Experiment 2

Study of the V-I Characteristics of UJT

Experiment 3

Study of the V-I Characteristics of MOSFET

Experiment 4

Study of the V-I Characteristics of IGBT

Experiment 5

Study of the V-I characteristics of DIAC

Experiment 6

Study of the V-I Characteristics of TRIAC

Experiment 7

Study of the V-I Characteristics of PUT

Experiment 8

Study of the Class B Commutation Circuit

Experiment 9

Study of the Class C Commutation Circuit

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

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13

15

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6

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8

9

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ST2712

Study of RC (Half Wave) Triggering Circuit

Experiment 14

Study of RC (Full Wave) Triggering Circuit

Experiment 15

Study of the SCR Triggered by UJT

Experiment 16

Study of the SCR Triggered by 555IC

Experiment 17

Study of the SCR Triggered by Op-Amp 741IC

37

39

41

43

45 Experiment 18

Study of the Ramp and Pedestal Triggering Circuit with Anti-

Parallel SCR in AC Load

Experiment 19

Study of the UJT Relaxation Oscillator

46

Experiment 20

Study of the Voltage Commutated Chopper

Experiment 21

Study of the Bedford Inverter

Experiment 22

Study of the Single Phase PWM Inverter using MOSFET and IGBT

50

52

54

56 Experiment 23

Study of the Half Wave Controlled Rectifier with R and RL Load

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

65

8.

9.

10.

Data Sheets

Warranty

List of Accessories

11.

List of other Trainers available from us are

71

85

85

86

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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 proper Mains cord

Ground the Instrument

:

Use only the mains cord designed for this instrument.

Ensure that the mains cord is suitable for your country.

:

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.

Observe Terminal Ratings :

To avoid fire or shock hazards, observe all ratings and marks on the instrument.

Use only the proper Fuse :

Use the fuse type and rating specified for this instrument.

Use in proper Atmosphere :

Please refer to operating conditions given in the manual.

1.

2.

Do not operate in wet / damp conditions.

Do not operate in an explosive atmosphere.

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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.

RoHS Compliance

Scientech Products are RoHS Complied.

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.

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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

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ST2712

Technical Specifications

Size of Breadboard

DC Power Supply on board

AC Power Supply on Board

Triggering Circuit on Board

Single Phase Rectifier

Firing Circuit on Board

SCR Assembly

Power Devices

Circuit Components on Board :

:

:

:

:

:

:

:

Pulse transformer on Board

Load selector

Test points

Weight

Dimensions (mm)

Power requirement

Power consumption

:

:

:

:

:

:

:

172.5 mm x 128.5mm

+5 V, -5 V; 500 mA,

+12V, -12 V; 500 mA

+15 V; 250 mA

+35V; -35V, 250 mA

18V-0V-18V

0V-15V

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%.

Firing angle control 0 º-180 º variables.

Four gate signal output with isolation

4 SCRs 2P4M, 600V, 2A

IGBT G4BC20S, MOSFET IRF Z44N,

UJT 2N2646, DIAC DB3, TRIAC BT136,

PUT 2N6027, SCR TYN616

Electrolytic Capacitor 10µF, 63V

Electrolytic Capacitor 1µF, 63V

Met. Capacitor 0.33µF, 63V

Diode 1N4007,

Inductor 220µH, 4.7µH, 10mH

2 nos. PT4502 1:1 and one is PT4503 1:1:1

6 load resistances- 47E/7W, 1K/1W, 1K/10W,

270E/5W, 120E/5W, 2K2 /2W

10 in numbers

5 Kgs. (approximately)

W420 x H100 x D255

230V +/- 10%; 50 Hz.

4VA (approximately)

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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 :

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 :

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.

Load section :

This block provides different loads 1K/1W, 1K/10W, 120E/5W, 47E/7W, 2K2/2W,

270E/5W. This load is selected by selector switch.

Pulse transformer :

This block provides pulse transformers for circuit isolation. In this block 2 transformers of 1:1 and one is 1:1:1.

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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.

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.

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ST2712

Experiment 1

Objective :

To study and plot the V-I Characteristics of SCR

Equipments Needed :

Equipments

1.

Resistance 470E, ¼ W

2.

3.

Resistance 2K2, 2W (on board)

Quantity

1

1

SCR TYN 616 (on board) 1

4.

Potentiometer 5K

Circuit diagram :

2

Circuit used to plot characteristics of SCR is shown in figure 1.

V-I Characteristics

Figure 1

Procedure :

Make circuit connections as shown in the figure 1 using patch cords.

1.

To plot the V -I characteristics proceed as follows.

2.

3.

4.

5.

Rotate both the potentiometer P

1

and P

2

in fully counter clockwise direction, connect voltmeter to point ‘6’ & ground to read V

G

and at point ‘3’ & ground to read V

AK

.

Connect ammeter at point ‘1’ & ‘2’ to indicate the current I

A

and at point ‘4’ &

‘5’ to indicate the gate current I

G

.

Switch on the power supply.

Vary potentiometer P

5.7mA, 5.8mA.).

2

to set the gate current I

G

to a lower value (5.6mA,

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ST2712

6.

Increase anode voltage V

A

gradually by varying potentiometer P

1

.

7.

Observe the current I

A

in the anode circuit, It shows almost zero current at the initial stage

8.

At certain point of positive anode voltage current I

A

shows sudden rise in reading & voltmeter reading falls down to almost zero. This action indicates the firing of SCR.

9.

10.

11.

If this not happens, repeat the procedure from step 5 for slightly higher value of gate current I

G

.

Try the various value of gate current to get the firing of SCR.

Keeping gate current constant observe precisely the firing voltage of SCR and record it in the observation table.

Also record the anode voltage V

A

& anode current after firing of the SCR.

Plot the graph of V

A

versus I

A

.

12.

13.

Observation Table :

Anode

Voltage

V

A

Anode current I

A

(mA) at constant value of Gate current

I

G = ____ mA I

G = ____ mA I

G = ____ mA

S.

No.

5.

6.

7.

8.

1.

2.

3.

4.

9.

10.

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ST2712

Experiment 2

Objective :

Study of the Characteristic of UJT and Calculate Interbase Resistance and

Intrinsic Standoff Ratio

Equipments Needed :

Equipments

1.

Quantity

Resistance 470E,

1

/

4

W 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

Emitter Characteristics

5.

6.

7.

Procedure :

Make circuit as shown in the figure 2 using patch cords.

To plot the emitter characteristics proceed as follows:

1.

Rotate both the potentiometer P

1

and P

2

fully in counter clockwise direction.

2.

Connect voltmeter between test point ‘6’ and ground to read V

BB

and other between test point ‘3’ and ground to read V

E

.

3.

4.

Connect ammeter between point ‘1’ and ‘2’ to measure the emitter current I

E and at point ‘4’ and ‘5’ to measure the base current I

B

.

Switch on the power supply.

Vary potentiometer P

2

Increase the emitter voltage V

Keep increasing V flows rapidly.

E

and set a value of voltage V

BB

E

in steps.

= 5 V.

Figure 2

until it drops on voltmeter, UJT fires and emitter current

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ST2712

8.

Record the corresponding Emitter current for each value of Emitter voltage V in an observation table 1.

E

9.

10.

Repeat the above procedure from step 8 for V

BB

= 10 V and 15 V.

Plot the graph of V

E

versus I

E

with the help of observation table 1.

Observation Table :

S.

No.

Emitter voltage

V

E

Emitter current I

E

(mA) at constant value of output voltage

V

BB

= 5V V

BB

= 10V V

BB

= 15V

10.

11.

12.

13.

14.

15.

5.

6.

7.

8.

9.

1.

2.

3.

4.

Calculations :

1.

Interbase Resistance(Rss)

It is the sum of resistance between base 1 & base2.

2.

R

BB

= R

B1

+ R

B2

It ranges from 4 to 10 K ohms when Ie = 0.

Intrinsic Stand-off Ratio (

η

)

η

= R

B1

(R

B1

+ R

B2

) = RB

B1

R

BB

It ranges from 0.51 to 0.82.

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ST2712

Experiment 3

Objective :

Study of the Characteristics of MOSFET

Equipments Needed :

Equipment

1.

Resistance 750E,

1

/

4

W

2.

3.

4.

5.

Resistance 1K, 1W

Resistance 470E,

1

/

4

W

Zener diode 5V

Potentiometer 5K

6.

Quantity

1

1

1

1

2

MOSFET IRFZ44N (on board) 1

Circuit diagram :

Circuit used to plot characteristics of MOSFET is shown in figure 3

Drain Characteristics

Figure 3

Procedure :

Make circuit as shown in the figure 3 using patch cords.

To plot drain characteristics proceed as follows:

1.

2.

Connect the circuit on the breadboard as shown in figure

Rotate both the potentiometer P

1

and P

2

fully in counter clockwise direction.

3.

Connect point ‘1’ and ‘2’ and connect ammeter between point ‘4’ and ‘5’.

4.

5.

Connect one voltmeter between point ‘6’ and ground to measure drain voltage

V

DS

other voltmeter between point ‘3’ and ground to measure gate voltage V

GS

.

Switch ‘On’ the power supply.

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ST2712

6.

Vary potentiometer P

2

and set a value of gate voltage V

GS value (3 V, 3.1 V, 3.2 V)

at some constant

7.

8.

9.

10.

Vary the potentiometer P

1

so as to increase the value of drain voltage V

DS

from zero to 35 V in step and measure the corresponding values of drain current I

D for different constant value gate voltage V

GS

in an observation table.

Rotate potentiometer P

1

fully in counter clockwise direction.

Repeat the procedure from step 6 for different sets of gate voltage V

GS

.

Plot a curve between drain voltage V

DS and drain current I

D

using suitable scale with the help of observation table. This curve is the required drain characteristic.

Observation Table :

S.

No.

Drain voltage

V

DS

Drain current I

D

(mA) at constant value of gate voltage

V

GS

= 3V V

GS

= 3.1V V

GS

= 3.2V

5.

6.

7.

1.

2.

3.

4.

8.

9.

10.

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ST2712

Experiment 4

Objective :

Study of the Characteristics of IGBT

Equipments Needed :

Equipment

1.

2.

3.

Resistance 25E, 5W

Resistance 1K,

1

/

4

W

Potentiometer 5K

Quantity

4.

IGBT G4BC20S (on board)

Circuit diagram :

1

1

2

1

Circuit used to plot the characteristics of an IGBT is shown in figure 4.

IGBT Characteristics

Figure 4

Procedure :

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 I

C

(mA).

3.

4.

Connect point ‘1’ and ‘2’.

5.

6.

Connect voltmeter between point ‘3’ and ground to measure the Gate voltage

V

GE and between point ‘6’ and ground to measure collector voltage V

CE.

Switch ‘On’ the power supply.

Vary the potentiometer P

1

in counterclockwise direction to set the gate voltage

V

GE

(between 4.8V and 6.5V).

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ST2712

7.

Vary the potentiometer P2 in clockwise direction so as to increase the value of collector-emitter voltage V

CE from 0 to 35V in step and measure the corresponding values of collector current I

C

for different constant value of gate voltage V

GE

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 V

GE

.

10.

Plot a curve between collector-emitter voltage current (V

CE

) and Collector current I

C

using suitable scale with the help of observation Table 1. This curve is the required collector characteristic.

Observation table :

S. No.

12.

13.

14.

15.

7.

8.

9.

10.

11.

16.

1.

2.

3.

4.

5.

6.

Collector

Voltage

V

CE

Collector current I

C

(mA) at constant value of gate voltage V

GE

(volt)

V

GE = V

V

GE = V

V

GE = V

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ST2712

Experiment 5

Objective :

Study of the Characteristics of DIAC and plot its V-I Characteristics Curve

Equipments Needed :

Equipment

1.

Resistance 1K, 1W (on board)

2.

3.

DIAC DB3 (on board)

Potentiometer 5K

Quantity

1

1

1

Circuit diagram :

Circuit used to plot different characteristics of DIAC is shown in figure 5.

V-I Characteristics

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Figure 5

4.

5.

6.

7.

8.

Procedure :

1.

Make circuit as shown in the figure 5 using patch cords.

2.

3.

To plot V-I characteristics proceed as follows.

Rotate both the potentiometer P

1

fully in counter clockwise direction.

Connect voltmeter across point ‘3’ & ground to read voltage V

Switch ‘On’ the power supply.

Put the +35 V switch ‘On’.

A

.

Connect ammeter between point ‘1’ & ‘2’ to indicate the current I

A.

9.

Vary the potentiometer P

1

so as to increase the value of DIAC voltage V

A

and measure the corresponding values of current I

A

in an observation table 1.

Plot the curve between + V

A

and + I

A

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ST2712

10.

Rotate potentiometer P

1

fully in counter clockwise direction.

11.

Switch ‘Off’ the power supply.

12.

13.

Put the switch towards -35 V.

Switch ‘On’ the power supply.

14.

Vary the potentiometer P

1

so as to increase the value of DIAC voltage V

A

and measure the corresponding values of current I

A

in an observation table.

15.

Plot the curve between –V

Observation Table :

A

and - I

A

.

Serial

Number

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

Diac

Voltage

Va

Diac

Current

Ia

Diac

Voltage

-Va

Diac

Current

-Ia

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ST2712

Experiment 6

Objective :

Study of the V-I Characteristics of TRIAC

Equipments Needed :

Equipment

1.

Resistance 470E,

1

/

4

W

2.

3.

Resistance 2K2, 2W (on board)

TRIAC BT136 (on board)

Quantity

1

1

1

4.

Potentiometer 5K

Circuit diagram :

2

Circuit used to plot different characteristics of TRIAC is shown in figure 6.

V-I Characteristics

Figure 6

6.

7.

8.

9.

10.

Procedure :

1.

2.

3.

4.

5.

Make circuit as shown in the figure 6 using patch cords.

To plot the V-I characteristics proceed as follows:

Rotate both the potentiometer P

1

and P

2

fully in counter clockwise direction.

Connect voltmeter between point ‘6’ and ground to read V

G

and between point

‘3’ and ground to read V

A

.

Connect one ammeter between point ‘1’ & ‘2’ to indicate the current I

A

and other between point ‘4’ & ‘5’ to indicates the gate current I

G

.

Switch on the power supply.

Put the switch towards +35 V.

Vary potentiometer P

2

to set the gate current I

G

to a lower value.

Increase anode voltage V

A

gradually by varying potentiometer P

1

.

Observe the current la in the anode circuit, It shows almost zero current at the initial stage.

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ST2712

11.

If this not happens, repeat the procedure from step 8 slight higher value of gate current I

G

.

Try the various value of gate current to get the firing of TRIAC.

12.

13.

Also record the anode voltage V

A

& anode current after firing of the TRIAC in table 1.

14.

15.

Rotate potentiometer P

1

fully in CCW direction.

Put the switch towards -35 V and repeat from step 6 and note down the reading in observation table 2.

Plot the graph of -V

A

versus -I

A

.

16.

Observation Table 1 :

S.

No.

Anode voltage

Va

Anode current Ia (mA) at constant value of

Gate current (when switch is to words 35V)

Ig = __ mA Ig = __ mA Ig = __ mA

4.

5.

6.

1.

2.

3.

7.

8.

9.

10.

Observation Table 2 :

S.

No.

Anode voltage

Anode current Ia (mA) at constant value of

Gate current (when switch is to words -35V)

Va

Ig = __ mA Ig = __ mA Ig = __ mA

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

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ST2712

Experiment 7

Objective :

Study of the Characteristics of PUT

Equipments Needed :

4.

5.

6.

Equipment

1.

Resistance 2K5,

1

/

4

W

2.

Resistance 10K,

1

/

4

W

3.

Resistance 2K2, 2W (on board)

Quantity

1

1

1

PUT 2N 6027 (on board) 1

Potentiometer 5K

Potentiometer 10K

1

1

Circuit diagram :

Circuit used to plot the characteristics of a PUT is shown in figure 7.

V-I Characteristics

Figure 7

Procedure :

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.

3.

Connect Ammeter between point ‘4’ and ‘5’ to measure gate current I

G

(mA) and between point ‘1’ and ‘2’ to measure anode current I

A

(mA).

Connect voltmeter between point ‘3’ and ground to measure the anode voltage

(V

A

).

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ST2712

4.

Connect voltmeter between point ‘6’ and ground to measure the Gate voltage

VG.

5.

6.

Switch ‘On’ the power supply.

Vary the potentiometer P

2

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 V

A

from

0 to 15V in step and measure the corresponding values of anode current I

A

for different constant value of gate voltage VG in an Observation Table 1.

8.

9.

Rotate the potentiometer P2 fully in the CCW direction.

Repeat the procedure from step 6 for different sets of gate voltage VG.

10.

Plot a curve between anode voltage (V

A

) and anode current I

A

using suitable scale with the help of observation Table 1. This curve is required V-I characteristic.

Observation Table :

S.

No.

Anode voltage V

A, anode current I

A and gate current I

G at different gate voltage

V

A

V

G

= 2.0V

I

A

I

G

V

A

V

G

= 5.0V

I

A

I

G

V

A

V

G

= 10.0V

I

A

I

G

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Experiment 8

Objective :

Study of Class B Commutation Circuit

Equipments Needed :

Equipment

1.

Resistance 1K,

1

/

4

W

2.

3.

Electrolytic Capacitor 2.2µF/25V

Inductor 10mH (on board)

Quantity

1

1

1

4.

SCR 2P4M (on board)

Circuit diagram :

1

The circuit diagram of class B commutation circuits as follows :

Class-B Commutation Circuit

4.

5.

Procedure :

1.

Connect circuit as shown above figure 8.

2.

3.

Connect Gate of SCR to G1 signal.

Switch on the power supply.

Connect oscilloscope across SCR and observe the waveform.

Connect oscilloscope across load resistance and observe waveform.

Figure 8

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Waveforms of Class-B Commutation

Figure 9

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Experiment 9

Objective :

Study of Class C Commutation Circuit

Equipments Needed :

Equipment

1.

Resistance 2K2,

1

/

4

W

2.

3.

MET. CAP. 0.1MFD (on board)

SCR TYN616

Quantity

2

1

2

Circuit diagram :

The circuit diagram of class C commutation circuits is as follows:

Class C Commutation Circuit

Procedure :

1.

2.

Connect circuit as shown above figure 10.

Connect G1 & G2 signal to gate of SCR.

3.

4.

5.

Switch ‘On’ the power supply.

Connect oscilloscope across SCR and observe waveform.

Connect oscilloscope across load resistance and observe waveform.

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Figure 10

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Waveforms of Class C Commutation

Scientech Technologies Pvt. Ltd.

Figure 11

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Experiment 10

Objective :

Study of Class D Commutation Circuit

Equipments Needed :

Equipment

1.

Resistance 511E,

1

/

4

W

2.

3.

Met. Cap 0.33 MFD (on board)

SCR 2P4M (on board)

Quantity

1

1

2

4.

5.

Inductor 68mH (on board)

Diode 1N4007 (on board)

1

1

Circuit diagram :

The circuit diagram of class D commutation circuits is as follows :

D Commutation Circuit

Procedure :

1.

Make circuit as shown in the figure 12.

2.

3.

4.

Connect G1 & G2 signal to gate of SCR1 & SCR2.

Switch ‘On’ the power supply.

Connect oscilloscope across SCR1& SCR2 and observe waveforms.

Figure 12

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Waveforms of Class-D Commutation

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Figure 13

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Experiment 11

Objective :

Study of Class-F Commutation Circuit

Equipments Needed :

Equipment

1.

Resistance 1K,10W (on board)

Quantity

1

2.

SCR 2P4M (on board) 1

Circuit diagram :

The circuit diagram of class D commutation circuits is as follows:

Class D Commutation Circuit

2.

3.

4.

Procedure :

1.

Connect circuit as shown above figure 14 using patch cords.

Connect GR1 signal to gate of SCR.

Switch ‘On’ the power supply.

Vary the firing control pot and observe waveform across load.

5.

Vary the firing control pot and observe waveform across SCR.

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Figure 14

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Waveform of Class F Commutation

Figure 15

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Experiment 12

Objective :

Study of the Resistor Triggering Circuit

Equipments Needed :

Equipment

1.

Resistance 1K,

1

/

4

W

2.

Resistance 511E,

1

/

4

W

3.

Potentiometer 1M (on board)

Quantity

1

2

1

4.

5.

SCR 2P4M (on board)

Diode 1N4007 (on board)

1

1

Circuit diagram :

The circuit diagram for SCR Triggering circuits is as follows:

Resistance Triggering Circuit

Figure 16

Procedure :

1.

Make circuit as shown in the figure 16 using patch cords

2.

3.

Rotate the potentiometer P1 fully in the CW (clockwise direction).

4.

Switch ‘On’ the power supply.

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

T = (

α

X 10ms) / 180

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Observation Table 1 :

S.No.

1.

2.

3.

4.

5.

6.

Load voltage(V)

Phase Angle

(

α

)

Waveforms of R Firing Circuit

Figure 17

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Experiments 13

Objective :

Study of the Resistor-Capacitor Triggering Circuit (Half Wave)

Equipments Needed :

Equipment

1.

Resistance 1K,

1

/

4

W

2.

3.

4.

Potentiometer 1M (on board)

SCR 2P4M (on board)

Diode 1N4007 (on board )

Quantity

1

1

1

2

5.

Met. Cap. 0.1 MFD(on board)

Circuit diagram :

1

The circuit diagram for SCR Triggering circuits is as follows:

Resistor-Capacitor Triggering Circuit

Figure 18

Procedure :

1.

Make circuit as shown in the figure 18 using patch cords.

2.

3.

4.

Rotate the potentiometers P fully in the CCW (Anticlockwise direction).

Switch ‘On’ the power supply.

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

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Observation Table :

S.

No.

1.

2.

3.

Load voltage(V) Phase Angle (

α

)

4.

5.

6.

Waveforms of RC Half Wave Firing Circuit

Figure 19

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Experiment 14

Objective :

Study of the Resistor-Capacitor Triggering Circuit (Full Wave)

Equipments Needed :

4.

5.

6.

Equipment

1.

Resistance 511E,

1

/

4

W

2.

3.

Resistance 1K, 1W (on board)

SCR 2P4M (on board)

Quantity

1

1

1

POT 1M (on board) 1

Ele. Cap 1MFD (on board)

Diode 1N4007

1

4

Circuit diagram :

The circuit diagram for SCR Triggering circuits is as follows:

Resistor - Capacitor Triggering Circuit

Now, connect the oscilloscope probe across the thyristor and observe the waveform.

Figure 20

Procedure :

1.

Make circuit as shown in the figure 20 using patch cords.

2.

3.

4.

Rotate the potentiometers P fully in the CW (clockwise direction).

Switch ‘On’ the power supply.

Connect the oscilloscope probe between the load test point TP5 and TP6 and observe the Phase angle and voltage.

5.

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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.

1.

2.

3.

4.

5.

6.

Load voltage (V) Phase Angle (

α

)

Waveform of RC Full Wave Firing Circuit

Figure 21

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Experiment 15

Objective :

Study of the triggering of SCR using UJT

Equipments Needed :

Equipment

1.

2.

Resistance 47K,

1

/

4

W

Resistance 47E,

1

/

4

W

3.

4.

5.

Resistance 100E, 2W

Resistance 220E,

1

/

4

W

Potentiometer 5K

6.

7.

8.

Ele. cap 1MFD (on board)

UJT 2N2646 (on board)

SCR TYN 616(on board)

Quantity

1

1

1

1

2

1

1

1

Circuit diagram :

The circuit diagram for Triggering of SCR using UJT is shown in figure 22.

Triggering SCR using UJT

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Figure 22

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Procedure :

1.

Make circuit as shown in the figure 22 using patch cords.

2.

3.

4.

5.

Connect Ammeter between points‘3’ and ‘4’ to measure Anode-cathode current

I

AK

(mA).

Connect Ammeter between points ‘1’ and ‘2’ to measure the gate Current I

G

(mA).

Connect voltmeter between point ‘5’ and ground to measure the anode-cathode voltage V

AK.

Rotate the potentiometer P

1 fully in clockwise direction and P

2 fully in the CCW

(counter clockwise direction).

6.

7.

Switch ‘On’ the power supply.

Vary the potentiometer P2 in clockwise direction so as to increase the anode to cathode voltage. Set this voltage above 11V.

8.

9.

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 I

AK

in an observation table 1.

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.

Observation table :

Set V

AK

= +12V

current I

AK

(mA)

Anode to cathode voltage V

AK

(V)

S.

No. I

G

(mA)

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Experiment 16

Objective :

Study of the Triggering of SCR using 555 IC

Equipments Needed :

6.

7.

8.

9.

Equipment

1.

Resistance 1K,

1

/

4

W

2.

3.

4.

5.

Resistance 100E, 2W

Resistance 5K,

1

/

4

W

IC 555 timer

Capacitor 0.01MFD

Ele. Cap 1MFD (on board)

Diode 1N4007 (on board)

SCR TYN 616(on board)

Potentiometer 5K

Quantity

1

1

1

1

1

1

1

1

2

Circuit diagram :

The circuit diagram for Triggering of SCR using 555 IC is as follows:

Triggering of SCR using 555 IC

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Figure 23

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Procedure :

1.

Make circuit as shown in the figure 23 using patch cords.

2.

3.

4.

5.

6.

7.

8.

9.

Connect Ammeter between points ‘3’ and ‘4’ to measure Anode-cathode current I

AK

(mA).

Connect Ammeter between points ‘1’ and ‘2’ to measure the gate Current I

G

(mA).

Connect voltmeter between point ‘5’ and ground to measure the anodecathode voltage V

AK.

Rotate the potentiometer P

1 fully in clockwise direction and P

2 fully in the

CCW (counter clockwise direction).

Switch ‘On’ the power supply.

Vary the potentiometer P2 in clockwise direction so as to increase the anode to cathode voltage. Set this voltage above 11V.

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 I

AK

in an Observation table 1.

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 :

Set V

AK

= +12V

Anode to cathode voltage V

AK

(V)

S.

No. I

G

(mA) current I

AK

(mA)

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Experiment 17

Objective :

Study of the Triggering of SCR using Op-Amp 741 IC

Equipments Needed :

1.

2.

3.

4.

5.

6.

7.

Equipment

Resistance 10K,

Zener 10V

Circuit diagram :

1

/

4

W

Resistance 120E, 5W (on board)

SCR TYN 616 (on board)

Potentiometer 5K

IC lm741

Met cap 0.047MFD

Quantity

3

1

1

1

2

1

1

The circuit diagram for Triggering of SCR using 74121 IC is shown in below figure

24.

Triggering of SCR using Op-Amp 555 IC

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Figure 24

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Procedure :

1.

Make circuit as shown in the figure 24 using patch cords.

3.

4.

2.

5.

6.

Connect Ammeter between point ‘3’ and ‘4’ to measure Anode-cathode current

I

AK

(mA).

Connect Ammeter between point ‘1’ and ‘2’ to measure the gate

Current I

G

(mA).

Connect voltmeter between point ‘5’ and ground to measure the anode-cathode voltage V

AK.

Rotate the potentiometer P

1 and P

2 fully in the clockwise direction.

Switch ‘On’ the power supply.

7.

Vary the potentiometer P

2

in anti clockwise direction so as to increase the anode to cathode voltage. Set this voltage above 11V.

8.

9.

Vary the potentiometer P

1

in clockwise direction so as to increase the value of gate current in step and measure the corresponding values of anode to cathode current I

AK

in an Observation Table 1.

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.

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Experiment 18

Objective :

Study of the Ramp and Pedestal Triggering using Anti-Parallel SCR in AC Load

Equipments Needed :

Equipment

1.

2.

3.

Resistance 220E, 2W

Resistance 20K,

1

/

4

W

Resistance 200E

,

1

/

4

W

4.

5.

Resistance 1K, 1W (on board)

Ele. Cap 1MFD (on board)

6.

7.

8.

9.

Diode 1N4007 (on board)

Zener 9V

Potentiometer 10K

UJT 2N2646 (on board)

10.

SCR 2P4M (on board)

11.

Pulse transformer 1:1:1 (on board)

Quantity

1

1

1

1

1

5

1

1

1

2

1

Circuit diagram :

The circuit diagram of basic anti-parallel SCR in AC load is shown in the below figure.

Ramp & Pedestal Triggering using Anti - Parallel SCR

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Figure 25

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Procedure :

1.

Make circuit as shown in the figure 25 using patch cords.

2.

3.

4.

5.

Rotate the potentiometer P1 fully in clockwise direction.

Connect the circuit as shown in the figure above using 2mm patch cords.

Switch ‘On’ the power supply.

Connect the oscilloscope and observe the output waveform across the Load resistor.

6.

7.

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 .

Observe the output waveform across load and across SCRs at firing angle is 90º and Plot the waveforms.

Observation Table :

S.

No.

Input

AC voltage

(Vrms)

Output across AC load circuit

Firing angle

(Degree)

Output voltage

(Vrms)

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Waveforms of Ramp and Pedestal Circuit

Figure 26

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Experiment 19

Objective :

Study of the UJT Relaxation Oscillator

Equipments Needed :

Apparatus

1.

Resistance 12K1,

1

/

4

W

2.

3.

Resistance 220E,

1

/

4

W

Resistance 100E,

1

/

4

W

4.

5.

Diode 1N4007

Met. Cap. 0.1MFD (on board)

6.

UJT 2N2646 (on board)

Quantity

1

1

1

1

1

1

Circuit diagram :

Circuit diagram of UJT relaxation oscillator is given below :

UJJ Relaxation Oscillator

Procedure :

1.

Make circuit as shown in the figure 27 using patch cords.

2.

3.

Rotate the potentiometer P

1 fully in clockwise direction.

Switch ‘On’ the power supply.

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Figure 27

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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 P

1

in clockwise direction so as to increase the frequency of the output.

Sketch the waveforms on the paper.

6.

Observation Table :

S.

No.

Minimum

Frequency (Hz)

Maximum

Frequency (Hz)

Waveform of UJT Relaxation Oscillator

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Figure 28

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Experiment 20

Objective :

Study of the Voltage Commutated Chopper

Equipments Needed :

4.

5.

6.

Equipment

1.

Resistance 511E,

1

/

4

W

2.

3.

Met. Cap. 0.33MFD (on board)

Inductor 68mH(on board)

Quantity

1

1

1

Inductor 10mH (on board) 1

SCR 2P4M (on board)

Diode 1N4007 (on board)

2

2

Circuit diagram :

Circuit diagram of voltage commutated chopper is given below :

Voltage Commutated Chopper

Figure 29

Procedure :

1.

Make circuit connection as shown above figure 29.

2.

3.

4.

5.

Connect G1& G2 to the gate of SCR1 and SCR2.

Switch ‘On’ the power supply.

Vary the PWM Potentiometer in fully clock wise direction.

Vary the frequency pot and observe the output across load and across SCR1&

SCR2.

6.

Sketch the waveforms on the paper.

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Observation Table :

Output voltage

(V)

S.

No.

Frequency (Hz)

Waveforms of Voltage Commutated Chopper

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Figure 30

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Experiment 21

Objective :

Study of the Bedford Inverter

Equipments Needed :

Equipment

1.

Resistance 30K,

1

/

4

W

2.

3.

Met. Cap 1MFD

SCR 2P4M (on board)

4.

Diode 1N4007 (on board)

Circuit diagram :

Quantity

1

4

4

4

Circuit diagram of Bedford inverter is given below :

SCR1, SCR2, SCR3, SCR4 =2P4M

C1, C2, C3, C4, = MET. 1µF/25V

D1, D2, D3, D4 = 1N4007

Bedford Inverter

Figure 31

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Procedure :

1.

Make circuit connection as shown above figure 31

2.

3.

4.

5.

Connect G1& G2 to the gate of SCR1 and SCR2.

Switch ‘On’ the power supply.

Rotates the PWM Potentiometer in fully clock wise direction.

Vary the frequency pot and observe the output across load and across SCR1&

SCR2.

Sketch the waveforms on the paper.

6.

Observation Table :

Frequency

(Hz)

Output voltage

(V)

S.

No.

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Experiment 22

Objective :

Study of the Single Phase PWM Inverter using MOSFET and IGBT

Equipments Needed :

Equipment

1.

MOSFET IRFZ 44N

2.

3.

IGBT G4BC20S

Resistance 1K,

1

/

4

W

4.

Tiny toggle switch 1P-2W

Circuit diagram :

Quantity

4

4

1

1

Figure 32

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.

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3.

Switch ‘On’ the power supply.

4.

Vary the frequency pot and observe waveform across load on oscilloscope.

5.

6.

Set the maximum frequency by frequency pot.

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.

8.

Switch off the power supply.

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)

Waveform of PWM Inverter

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Figure 34

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Experiment 23

Objective :

Study of the Half – Wave Controlled Rectifier with Resistive Load

Equipments Needed :

Equipment

1.

SCR 2P4M (on board)

2.

3.

Quantity

1

Resistance 1K, 10W (on board) 1

Resistance 270E, 5W (on board) 1

4.

Inductor 68mH (on board)

Circuit diagram :

2

The circuit diagram of basic half-wave controlled rectifier is shown in the below figure 35

Half – Wave Controlled Rectifier

Figure 35

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Procedure :

Make the circuit shown in the figure 35.

1.

Rotate the firing control pot in full clockwise direction.

2.

3.

Switch ‘On’ the power.

Measure the ac voltage (Vrms) by voltmeter between point 0V-15V and calculate Em by Em =1.414 X Vrms.

4.

5.

6.

7.

8.

Switch ‘Off’ the power.

Connect the circuit of half-wave rectifier as shown figure 36.

Switch ‘On’ the power.

Connect the oscilloscope and voltmeter across the load.

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 I

DC

current and power P

DC

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.

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Waveform of Half Wave Rectifier with Resistive Load

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Figure 36

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Waveform of Half Wave Rectifier with Resistive- Inductive Load

Figure 37

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Experiment 24

Objective :

Study of the Full – Wave Controlled Rectifier (mid-point configuration) with

Resistive Load.

1.

2.

3.

4.

Equipments Needed :

Equipment

SCR 2P4M (on board)

Resistance 1K, 10W (on board)

Quantity

2

1

Resistance 270E, 5W (on board)

Inductor 68mH (on board)

1

2

Circuit diagram :

The circuit diagram of basic full – wave controlled rectifier (mid- point configuration) is shown in the below figure 38

Full – Wave Controlled Rectifier

Figure 38

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Procedure :

Make connections according to figure 38.

1.

Rotate the firing control Potentiometer in full clockwise direction.

2.

3.

Switch ‘On’ the power.

Measure the ac voltage (Vrms) by voltmeter between point 0V-18V and calculate Em by Em =1.414 X Vrms.

4.

5.

Switch ‘Off’ the power.

Connect the circuit of full-wave controlled rectifier (mid-point configuration) as shown figure 9 using 2 mm patch cords.

6.

7.

8.

Switch ‘On’ the power.

Connect the oscilloscope and voltmeter across the load.

9.

Vary the firing control pot and set on 30º, 60º, 90º, 120º and 150º firing angles using T = (

α

X 10ms) / 180.

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 I

DC

current and power P

DC

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.

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Waveform of Full Wave Rectifier (mid-point) with Resistive Load

Figure 39

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Waveform of Full Wave Rectifier (mid-point) with Resistive-Inductive Load

Figure 40

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Experiment 25

Objective :

Study of the Fully Controlled Bridge Rectifier with Resistive Load

Equipments Needed :

Equipment

1.

SCR 2P4M (on board)

2.

3.

Resistance 1K, 10W (on board)

Resistance 270E, 5W (on board)

Quantity

4

1

1

4.

Inductor 68mH (on board)

Circuit diagram :

2

The circuit diagram of basic fully controlled bridge rectifier is shown in the below figure 41

Controlled Bridge Rectifier

Figure 41

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Procedure :

1.

Rotate the firing control Potentiometer in full clockwise direction.

2.

3.

4.

5.

Switch ‘On’ the power.

Measure the ac voltage (Vrms) by voltmeter between point 0V-15V and calculate Em by Em =1.414 X Vrms.

Switch ‘Off’ the power.

Connect the circuit of fully-controlled bridge rectifier as shown figure 42 using

2 mm patch cords.

6.

7.

8.

9.

Switch ‘On’ the power.

Connect the oscilloscope and voltmeter across the load.

Vary the firing control pot and set on 30º, 60º, 90º, 120º and 150º firing angles using T = (

α

X 10ms) / 180 .

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 I

DC

current and power P

DC

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.

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Waveform of Full Wave Bridge Rectifier with Resistive Load

Figure 42

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Waveform of Full Wave Bridge Rectifier with Resistive - Inductive Load

Figure 43

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Data Sheets

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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

3.

4.

a) b) c) d)

The product is not operated as per the instruction given in the operating manual.

The agreed payment terms and other conditions of sale are not followed.

The customer resells the instrument to another party.

Any attempt is made to service and modify the instrument.

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.

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.

List of Accessories

1.

2.

6.

7.

8.

3.

4.

5.

Bread Boards ........................................................................................... 2 Nos.

Connecting Wires .................................................................................. 20 Nos.

2mm to 1mm Patch Cords ..................................................................... 15 Nos.

2mm Patch Cords (Red) .......................................................................... 4 Nos.

2mm Patch Cords (Black)........................................................................ .4 Nos.

2mm Patch Cords (Blue) ....................................................................... 12 Nos.

Mains Cord ................................................................................................1 No. e-Manual....................................................................................................1 No.

Updated 20-04-2009

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PE13

PE14

PE15

PE16

PE40

PE41

PE42

PE43

PE44

ST2701

ST2702

ST2703

ST2704

ST2705

ST2706

ST2707

ST2708

List of other Trainers available from us are :

Model Name

PE01

UJT Characteristics

PE02

PE03

MOSFET Characteristics

SCR Characteristics

PE04

PE05

PE06

PE07

PE10

PE11

PE12

TRIAC Characteristics

DIAC Characteristics

IGBT Characteristics

PUT Characteristics

SCR Triggering (R, RC Full wave, RC Half wave)

SCR Triggering (UJT)

SCR Triggering (IC555)

SCR Triggering (IC74121)

Ramp and Pedestal Triggering

SCR Triggering (IC741)

SCR Triggering (PUT)

SCR Lamp Flasher

SCR Alarm Circuit

Series Inverter

UJT Relaxation Oscillator

Single Phase PWM Inverter

IGBT Characteristics

SCR Triggering (R, RC Half wave, RC Full wave)

SCR Triggering Techniques

Triggering of SCR using 74121 IC

SCR Lamp Flasher

SCR Alarm Circuit

Series Inverter

Single Phase Controlled Rectifier (with Ramp Comparator Firing

Scheme)

ST2709

ST2710

ST2711

ST2712

ST2713

ST2714

ST2715

ST2716

ST2717

ST2718

ST2719

ST2720

ST2722

ST2723

Single Phase Controlled Rectifier (Cosine Firing Scheme)

Single Phase Converter Firing Techniques (by TCA 785IC and

Triangular Comparator)

Lamp Dimmer

Electronics Power Lab

Single Phase Cyclo-Converter

Speed Control of Universal Motor using SCR

Speed Control of AC Motor using TRIAC

Microcontroller Based Firing Circuit for Controlled Rectifier

SCR Commutation Circuits

Bedford & Parallel Inverter

Step-Up Chopper

Single Phase Bridge Inverter

Step-Down Chopper

AC Chopper

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