St2712w Laboratorium

ST2712__WL_.doc

Power Electronics Lab ST2712

Operating Manual Ver 1.1

An ISO 9001 : 2000 company

94-101, Electronic Complex Pardesipura, Indore- 452010, INDIATel : 91-731- 2570301/02, 4211100Fax: 91- 731- 2555643E-mail : [email protected] Website : www.scientech.bz Toll free No. : 1800-103-5050

ST2712Scientech Technologies Pvt. Ltd.2

Power Electronics Lab ST2712Table of ContentsSafety Instructions5Introduction6Features7Technical Specifications8Functions of Various Blocks9Operating Instructions & Panel Control Description10ExperimentsExperiment 111Study of the V-I Characteristics of SCRExperiment 213Study of the V-I Characteristics of UJTExperiment 315Study of the V-I Characteristics of MOSFETExperiment 417Study of the V-I Characteristics of IGBTExperiment 519Study of the V-I characteristics of DIACExperiment 621Study of the V-I Characteristics of TRIACExperiment 723Study of the V-I Characteristics of PUTExperiment 825Study of the Class B Commutation CircuitExperiment 927Study of the Class C Commutation CircuitExperiment 1029Study of the Class D Commutation CircuitExperiment 1131Study of the Class F Commutation CircuitExperiment 1233Study of R Triggering CircuitExperiment 1335

ST2712

Scientech Technologies Pvt. Ltd.10

Study of RC (Half Wave) Triggering Circuit Experiment 1437Study of RC (Full Wave) Triggering Circuit Experiment 1539Study of the SCR Triggered by UJT Experiment 1641Study of the SCR Triggered by 555IC Experiment 1743Study of the SCR Triggered by Op-Amp 741IC Experiment 1845Study of the Ramp and Pedestal Triggering Circuit with Anti- Parallel SCR in AC Load Experiment 1946Study of the UJT Relaxation Oscillator Experiment 2050Study of the Voltage Commutated Chopper Experiment 2152Study of the Bedford Inverter Experiment 2254Study of the Single Phase PWM Inverter using MOSFET and IGBT Experiment 2356Study of the Half Wave Controlled Rectifier with R and RL Load Experiment 2461Study of the Full Wave Controlled mid-point rectifier with R and RL Load Experiment 2565Study of the Fully Controlled Bridge Rectifier with R and RL Load2. Data Sheets713. Warranty854. List of Accessories855. List of other Trainers available from us are86

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: 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 protectiveearth 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 thisinstrument.Use in proper Atmosphere : Please refer to operating conditions given in themanual.1. Do not operate in wet / damp conditions.2. Do not operate in an explosive atmosphere.

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 ComplianceScientech 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 450C at the tip as the melting temperature of the unleaded solder is higher than the leaded solder.

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

Technical Specifications

Size of Breadboard:172.5 mm x 128.5mmDC Power Supply on board:+5 V, -5 V; 500 mA,+12V, -12 V; 500 mA+15 V; 250 mA+35V; -35V, 250 mAAC Power Supply on Board:18V-0V-18V0V-15VTriggering 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 GateSignal is 0 to 100%.Single Phase Rectifier:Firing angle control 0 -180 variables. Firing Circuit on BoardFour gate signal output with isolation SCR Assembly:4 SCRs 2P4M, 600V, 2APower Devices:IGBT G4BC20S, MOSFET IRF Z44N,UJT 2N2646, DIAC DB3, TRIAC BT136, PUT 2N6027, SCR TYN616Circuit Components on Board:Electrolytic Capacitor 10F, 63VElectrolytic Capacitor 1F, 63V Met. Capacitor 0.33F, 63V Diode 1N4007,Inductor 220H, 4.7H, 10mHPulse transformer on Board:2 nos. PT4502 1:1 and one is PT4503 1:1:1Load selector:6 load resistances- 47E/7W, 1K/1W, 1K/10W, 270E/5W, 120E/5W, 2K2 /2WTest points:10 in numbersWeight:5 Kgs. (approximately)Dimensions (mm):W420 x H100 x D255Power requirement:230V +/- 10%; 50 Hz.Power consumption:4VA (approximately)

DC Power :

Functions of Various Blocks

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. 1F/63V, MET. 0.1F/63V and MET. Cap.0.33F/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.

Operating Instructions and Panel Control DescriptionThe 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.

Objective :

Experiment 1

To study and plot the V-I Characteristics of SCR Equipments Needed :EquipmentsQuantity1. Resistance 470E, W12. Resistance 2K2, 2W (on board)13. SCR TYN 616 (on board)14. Potentiometer 5K2Circuit diagram :Circuit used to plot characteristics of SCR is shown in figure 1.

Procedure :

V-I Characteristics

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.).

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 stage8. 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 :

S.No.Anode VoltageVAAnode current IA (mA) at constant value of Gate current

IG = ____mAIG = ____mAIG = ____mA

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

Objective :

Experiment 2

Study of the Characteristic of UJT and Calculate Interbase Resistance and Intrinsic Standoff RatioEquipments Needed :EquipmentsQuantity

1.Resistance 470E, 1/4W2

2.Potentiometer 5K2

3.UJT 2N2646 (on board)1

Circuit diagram :Circuit used to plot characteristics of Unijunction transistor is shown in figure 2

Procedure :

Emitter Characteristics

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.

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 voltage VEEmitter current IE (mA) at constant value of output voltage

VBB = 5VVBB = 10VVBB = 15V

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

Calculations :1. Interbase Resistance(Rss)It is the sum of resistance between base 1 & base2. RBB = RB1 + RB2It ranges from 4 to 10 K ohms when Ie = 0.2. Intrinsic Stand-off Ratio ()= RB1 (RB1 + RB2) = RBB1 RBBIt ranges from 0.51 to 0.82.

Objective :

Experiment 3

Study of the Characteristics of MOSFET Equipments Needed :EquipmentQuantity


2.Resistance 1K, 1W1


4.Zener diode 5V1

5.Potentiometer 5K2

6.MOSFET IRFZ44N (on board)1

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

Procedure :

Drain Characteristics

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 figure2. 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.

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 voltage VDSDrain current ID (mA) at constant value of gate voltage

VGS = 3VVGS = 3.1VVGS = 3.2V

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

Objective :

Experiment 4

Study of the Characteristics of IGBT Equipments Needed :EquipmentQuantity

1.Resistance 25E, 5W1

2.Resistance 1K, 1/4W1

3.Potentiometer 5K2

4.IGBT G4BC20S (on board)1

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

Procedure :

IGBT Characteristics

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 point4 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).

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.Collector Voltage VCECollector current IC (mA) at constant value of gate voltage VGE(volt)

VGE = VVGE = VVGE = V

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

Objective :

Experiment 5

Study of the Characteristics of DIAC and plot its V-I Characteristics Curve Equipments Needed :EquipmentQuantity1. Resistance 1K, 1W (on board)12. DIAC DB3 (on board)13. Potentiometer 5K1Circuit diagram :Circuit used to plot different characteristics of DIAC is shown in figure 5.

Procedure :

V-I Characteristics

Figure 5

1. 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

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 NumberDiac Voltage VaDiac Current IaDiac Voltage-VaDiac Current-Ia

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

Objective :

Experiment 6

Study of the V-I Characteristics of TRIAC Equipments Needed :EquipmentQuantity1. Resistance 470E, 1/4W12. Resistance 2K2, 2W (on board)13. TRIAC BT136 (on board)14. Potentiometer 5K2Circuit diagram :Circuit used to plot different characteristics of TRIAC is shown in figure 6.

Procedure :

V-I Characteristics

Figure 6

1. Make circuit as shown in the figure 6 using patch cords.2. To plot the V-I characteristics proceed as follows:3. Rotate both the potentiometer P1 and P2 fully in counter clockwise direction.4. Connect voltmeter between point 6 and ground to read VG and between point 3 and ground to read VA.5. Connect one ammeter between point 1 & 2 to indicate the current IA and other between point 4 & 5 to indicates the gate current IG.6. Switch on the power supply.7. Put the switch towards +35 V.8. Vary potentiometer P2 to set the gate current IG to a lower value.9. Increase anode voltage VA gradually by varying potentiometer P1.10. Observe the current la in the anode circuit, It shows almost zero current at the initial stage.

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 voltage VaAnode current Ia (mA) at constant value of Gate current (when switch is to words 35V)

Ig = __ mAIg = __ mAIg = __ mA

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

Observation Table 2 :

S.No.Anode voltage VaAnode current Ia (mA) at constant value of Gate current (when switch is to words -35V)

Ig = __ mAIg = __ mAIg = __ mA

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

Objective :

Experiment 7

Study of the Characteristics of PUT Equipments Needed :EquipmentQuantity1. Resistance 2K5, 1/4W12. Resistance 10K, 1/4W13. Resistance 2K2, 2W (on board)14. PUT 2N 6027 (on board)15. Potentiometer 5K16. Potentiometer 10K1Circuit diagram :Circuit used to plot the characteristics of a PUT is shown in figure 7.

Procedure :

V-I Characteristics

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).

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 :

S.No.Anode voltage VA, anode current IA and gate current IG at different gate voltage

VG = 2.0VVG = 5.0VVG = 10.0V

VAIAIGVAIAIGVAIAIG

Objective :

Experiment 8

Study of Class B Commutation Circuit Equipments Needed :EquipmentQuantity1. Resistance 1K, 1/4W12. Electrolytic Capacitor 2.2F/25V13. Inductor 10mH (on board)14. SCR 2P4M (on board)1Circuit diagram :The circuit diagram of class B commutation circuits as follows :

Procedure :

Class-B Commutation Circuit

Figure 8

1. 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.

Waveforms of Class-B Commutation

Figure 9

Objective :

Experiment 9

Study of Class C Commutation Circuit Equipments Needed :EquipmentQuantity1. Resistance 2K2, 1/4W22. MET. CAP. 0.1MFD (on board)13. SCR TYN6162Circuit diagram :The circuit diagram of class C commutation circuits is as follows:

Procedure :

Class C Commutation Circuit

Figure 10

1. 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.

Waveforms of Class C Commutation

Figure 11

Objective :

Experiment 10

Study of Class D Commutation Circuit Equipments Needed :EquipmentQuantity


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 :

Procedure :

D Commutation Circuit

Figure 12

1. 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.

Waveforms of Class-D Commutation

Figure 13

Objective :

Experiment 11

Study of Class-F Commutation Circuit Equipments Needed :EquipmentQuantity1. Resistance 1K,10W (on board)12. SCR 2P4M (on board)1Circuit diagram :The circuit diagram of class D commutation circuits is as follows:

Procedure :

Class D Commutation Circuit

Figure 14

1. 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.

Waveform of Class F Commutation

Figure 15

Objective :

Experiment 12

Study of the Resistor Triggering Circuit Equipments Needed :EquipmentQuantity



3.Potentiometer 1M (on board)1



Circuit diagram :The circuit diagram for SCR Triggering circuits is as follows:

Procedure :

Resistance Triggering Circuit

Figure 16

1. Make circuit as shown in the figure 16 using patch cords2. 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 T = ( X 10ms) / 180

Observation Table 1 :

S.No.Load voltage(V)Phase Angle ()

1.

2.

3.

4.

5.

6.

Waveforms of R Firing Circuit

Figure 17

Objective :

Experiments 13

Study of the Resistor-Capacitor Triggering Circuit (Half Wave) Equipments Needed :EquipmentQuantity


2.Potentiometer 1M (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:

Procedure :

Resistor-Capacitor Triggering Circuit

Figure 18

1. 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 = ( X 10ms) / 180

Observation Table :

S.No.Load voltage(V)Phase Angle ()

1.

2.

3.

4.

5.

6.

Waveforms of RC Half Wave Firing Circuit

Figure 19

Objective :

Experiment 14

Study of the Resistor-Capacitor Triggering Circuit (Full Wave) Equipments Needed :EquipmentQuantity1. Resistance 511E, 1/4W12. Resistance 1K, 1W (on board)13. SCR 2P4M (on board)14. POT 1M (on board)15. Ele. Cap 1MFD (on board)16.Diode 1N40074Circuit diagram :The circuit diagram for SCR Triggering circuits is as follows:

Procedure :

Resistor - Capacitor Triggering Circuit

Figure 20

1. 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.

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 = ( X 10ms) / 180Observation Table :

S. No.Load voltage (V)Phase Angle ()

1.

2.

3.

4.

5.

6.

Waveform of RC Full Wave Firing Circuit

Figure 21

Objective :

Experiment 15

Study of the triggering of SCR using UJT Equipments Needed :EquipmentQuantity





5.Potentiometer 5K2

6.Ele. cap 1MFD (on board)1


8.SCR TYN 616(on board)1

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

Triggering SCR using UJT

Figure 22

Procedure :1. Make circuit as shown in the figure 22 using patch cords.2. Connect Ammeter between points3 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 andd 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 VAK = +12V

S.No.Gate current IG (mA)Anode to cathode current IAK (mA)Anode to cathode voltage VAK (V)

Objective :

Experiment 16

Study of the Triggering of SCR using 555 IC Equipments Needed :EquipmentQuantity1. Resistance 1K, 1/4W12. Resistance 100E, 2W13. Resistance 5K, 1/4W14. IC 555 timer15. Capacitor 0.01MFD16. Ele. Cap 1MFD (on board)17. Diode 1N4007 (on board)18. SCR TYN 616(on board)19. Potentiometer 5K2Circuit diagram :The circuit diagram for Triggering of SCR using 555 IC is as follows:

Triggering of SCR using 555 IC

Figure 23

Procedure :1. 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 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 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 VAK = +12V

S.No.Gate current IG (mA)Anode to cathode current IAK (mA)Anode to cathode voltage VAK (V)

Objective :

Experiment 17

Study of the Triggering of SCR using Op-Amp 741 IC Equipments Needed :EquipmentQuantity1. Resistance 10K, 1/4W32. Resistance 120E, 5W (on board)13. Zener 10V14. SCR TYN 616 (on board)15. Potentiometer 5K26.IC lm74117.Met cap 0.047MFD1Circuit diagram :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

Procedure :1. 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 anodecathode voltage and current of SCR.11. To repeat the experiment switch off the power supply and follow the procedure from step 4.

Objective :

Experiment 18

Study of the Ramp and Pedestal Triggering using Anti-Parallel SCR in AC Load Equipments Needed :EquipmentQuantity




4.Resistance 1K, 1W (on board)1

5.Ele. Cap 1MFD (on board)1


7.Zener 9V1

8.Potentiometer 10K1



11.Pulse transformer 1:1:1 (on board)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

Figure 25

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 30, 60, 90, 120, and 150 by varying the pot P1 and note the reading of output voltage. Angle in time convert using T = ( X 10ms) / 180 .7. Observe the output waveform across load and across SCRs at firing angle is 90 and Plot the waveforms.

Observation Table :

S.No.Input AC voltage(Vrms)Output across AC load circuit

Firing angle (Degree)Output voltage (Vrms)

Waveforms of Ramp and Pedestal Circuit

Figure 26

Objective :

Experiment 19

Study of the UJT Relaxation Oscillator Equipments Needed :ApparatusQuantity1. Resistance 12K1, 1/4W12. Resistance 220E, 1/4W13. Resistance 100E, 1/4W14.Diode 1N400715. Met. Cap. 0.1MFD (on board)16. UJT 2N2646 (on board)1Circuit diagram :Circuit diagram of UJT relaxation oscillator is given below :

Procedure :

UJJ Relaxation Oscillator

Figure 27

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.

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)

Waveform of UJT Relaxation Oscillator

Figure 28

Objective :

Experiment 20

Study of the Voltage Commutated Chopper Equipments Needed :EquipmentQuantity1. Resistance 511E, 1/4W12. Met. Cap. 0.33MFD (on board)13. Inductor 68mH(on board)14. Inductor 10mH (on board)15. SCR 2P4M (on board)26. Diode 1N4007 (on board)2Circuit diagram :Circuit diagram of voltage commutated chopper is given below :

Procedure :

Voltage Commutated Chopper

Figure 29

1. 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.

Observation Table :

S.No.Frequency (Hz)Output voltage (V)

Waveforms of Voltage Commutated Chopper

Figure 30

Objective :Study of the Bedford Inverter Equipments Needed :

Experiment 21

EquipmentQuantity1. Resistance 30K, 1/4W12. Met. Cap 1MFD43. SCR 2P4M (on board)44. Diode 1N4007 (on board)4Circuit diagram :Circuit diagram of Bedford inverter is given below :

SCR1, SCR2, SCR3, SCR4 =2P4M C1, C2, C3, C4, = MET. 1F/25V D1, D2, D3, D4 = 1N4007

Bedford Inverter

Figure 31

Procedure :1. Make circuit connection as shown above figure 312. 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)

Objective :

Experiment 22

Study of the Single Phase PWM Inverter using MOSFET and IGBT Equipments Needed :EquipmentQuantity

1.MOSFET IRFZ 44N4

2.IGBT G4BC20S4


4.Tiny toggle switch 1P-2W1

Circuit diagram :

Figure 32

Procedure :

Single Phase PWM Inverter

Figure 33

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.

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)

Waveform of PWM Inverter

Figure 34

Objective :

Experiment 23

Study of the Half Wave Controlled Rectifier with Resistive Load Equipments Needed :EquipmentQuantity1. SCR 2P4M (on board)12. Resistance 1K, 10W (on board)13. Resistance 270E, 5W (on board)14. Inductor 68mH (on board)2Circuit diagram :The circuit diagram of basic half-wave controlled rectifier is shown in the below figure 35

Half Wave Controlled Rectifier

Figure 35

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 30, 60, 90, 120 and 150 firing angles using T = ( 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 90.11. 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 90.

58

ST2712Scientech Technologies Pvt. Ltd.Observation Table :

S.No.Input AC VoltageFiring AngleAverage Output Voltage Across LoadAverage Load Current (IDC)Average Output Power

In (VRMS)In (VM)In Deg.In Time (ms)Measured Voltage (Vo)Calculated Voltage (VDC)Measured (Io)Vo / RLCalculated (IDC)VDC / RLMeasured PoVo X IoCalculated (PDC)VDC X IDC

Scientech Technologies Pvt. Ltd.59Waveform of Half Wave Rectifier with Resistive Load

Figure 36

Waveform of Half Wave Rectifier with Resistive- Inductive LoadFigure 37

Objective :

Experiment 24

Study of the Full Wave Controlled Rectifier (mid-point configuration) with Resistive Load.Equipments Needed :EquipmentQuantity



3.Resistance 270E, 5W (on board)1


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

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 30, 60, 90, 120 and 150 firing angles using T = ( 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 90.11. 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 90.

63

ST2712Scientech Technologies Pvt. Ltd.Observation Table :



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

Figure 39

Scientech Technologies Pvt. Ltd.64

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

Figure 40

Objective :

Experiment 25

Study of the Fully Controlled Bridge Rectifier with Resistive Load Equipments Needed :EquipmentQuantity



3.Resistance 270E, 5W (on board)1


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

Controlled Bridge Rectifier

Figure 41

Procedure :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-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 30, 60, 90, 120 and 150 firing angles using T = ( 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 90 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 90 with resistive and resistive-inductive load.

ST2712Scientech Technologies Pvt. Ltd.68



Scientech Technologies Pvt. Ltd.69Waveform of Full Wave Bridge Rectifier with Resistive Load

Figure 42

Waveform of Full Wave Bridge Rectifier with Resistive - Inductive Load

Figure 43

Data Sheets

Warranty1. 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, ifa) 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.

List of Accessories1.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.

Updated 20-04-2009

List of other Trainers available from us are : ModelNamePE01UJT Characteristics PE02MOSFET Characteristics PE03SCR CharacteristicsPE04TRIAC CharacteristicsPE05DIAC CharacteristicsPE06IGBT CharacteristicsPE07PUT CharacteristicsPE10SCR Triggering (R, RC Full wave, RC Half wave)PE11SCR Triggering (UJT) PE12SCR Triggering (IC555) PE13SCR Triggering (IC74121)PE14Ramp and Pedestal Triggering PE15SCR Triggering (IC741) PE16SCR Triggering (PUT)PE40SCR Lamp FlasherPE41SCR Alarm CircuitPE42Series InverterPE43UJT Relaxation Oscillator PE44Single Phase PWM Inverter ST2701IGBT CharacteristicsST2702SCR Triggering (R, RC Half wave, RC Full wave)ST2703SCR Triggering Techniques ST2704Triggering of SCR using 74121 IC ST2705SCR Lamp FlasherST2706SCR Alarm CircuitST2707Series InverterST2708Single Phase Controlled Rectifier (with Ramp Comparator Firing Scheme)ST2709Single Phase Controlled Rectifier (Cosine Firing Scheme)ST2710Single Phase Converter Firing Techniques (by TCA 785IC and Triangular Comparator)ST2711Lamp DimmerST2712Electronics Power LabST2713Single Phase Cyclo-ConverterST2714Speed Control of Universal Motor using SCRST2715Speed Control of AC Motor using TRIACST2716Microcontroller Based Firing Circuit for Controlled RectifierST2717 SCR Commutation Circuits ST2718 Bedford & Parallel Inverter ST2719 Step-Up ChopperST2720Single Phase Bridge Inverter ST2722Step-Down Chopper ST2723AC Chopper

St2712w Laboratorium

Documents

Transcript of St2712w Laboratorium