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    SINGLE PHASE HALF CONTROLLED BRIDGE CONVERTER

    Aim: To study the single phase half controlled bridge converter with R & RL Load.

    Apparatus required:

    S.No. Name of the equipment Range Qty01 Single phase half controlledbridge converter power circuitand firing circuit

    - 01

    02 CRO with deferential module - 0103 Patch chords and probes - Adequate04 Isolation Transformer Tapping from 30V-

    230V / 5A01

    05 Variable Rheostat 0-200 / 5A 0106 Inductor 0-50-150 mH / 5A 0107 DC Voltmeter 0-300V 0108 DC Ammeter 0-5A 01

    CIRCUIT DIAGRAM:

    PROCEDURE:

    1. Make all connections as per the circuit diagram

    2. Connect first 30V AC supply from Isolation Transformer to circuit

    3. Connect firing pulses from firing circuit to Thyristors as indication in circuit

    4. Connect resistive load 200 / 5A to load terminals and switch ON the MCB and IRS

    switch and trigger output ON switch.

    5. Connect CRO probes and observe waveforms in CRO, Ch-1 or Ch-2, across load and

    device in single phase half controlled bridge converter.

    6. By varying firing angle gradually up to 1800 and observe related waveforms

    7. Measure output voltage and current by connecting AC voltmeter & Ammeter

    8. Tabulate all readings for various firing angles.

    9. For RL Load connect a large inductance load in series with Resistance and observe all

    waveforms and readings as same as above.

    10. Observe the various waveforms at different points in circuit by varying the Resistive

    Load and Inductive Load.

    11. Calculate the output voltage and current by theoretically and compare with it

    practically obtained values.

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    TABULAR COLUMN:

    S.No. Input Voltage(V in)

    Firingangle inDegrees

    Output voltage (V0) Output Current (I0)

    Theoretical Practical Theoretical Practical

    MODULE CALCULATIONS:

    V0 = (2V / ) * (1+Cos)

    I0 = (2V / R) * (1+Cos )

    = Firing AngleV = RMS Value across transformer output

    MODEL GRAPH:

    RESULT:

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    SINGLE PHASE FULLY CONTROLLED BRIDGE CONVERTER

    Aim: To study the single phase fully controlled bridge converter with R & RL Load.

    Apparatus required:

    S.No. Name of the equipment Range Qty01 Single phase full controlled bridge

    converter power circuit and firingcircuit

    - 01

    02 CRO with deferential module - 0103 Patch chords and probes - Adequate04 Isolation Transformer Tapping from 30V to

    230V / 5A01

    05 Variable Rheostat 0-200 / 5A 0106 Inductor 0-50-150 mH / 5A 0107 DC Voltmeter 0-300V 01

    08 DC Ammeter 0-5A 01

    CIRCUIT DIAGRAM:

    PROCEDURE:

    1. Make all connections as per the circuit diagram

    2. Connect firstly 30V AC supply from Isolation Transformer to circuit

    3. Connect firing pulses from firing circuit to Thyristors as indication in circuit

    4. Connect resistive load 200 / 5A to load terminals and switch ON the MCB and IRS switch

    and trigger output ON switch.

    5. Connect CRO probes and observe waveforms in CRO, Ch-1 or Ch-2, across load and

    device in single phase half controlled bridge converter.

    6. By varying firing angle gradually up to 1800 and observe related waveforms

    7. Measure output voltage and current by connecting AC voltmeter & Ammeter

    8. Tabulate all readings for various firing angles.

    9. For RL Load connect a large inductance load in series with Resistance and observe all

    waveforms and readings as same as above.

    10.Observe the various waveforms at different points in circuit by varying the Resistive Load

    and Inductive Load.

    11.Calculate the output voltage and current by theoretically and compare with it practically

    obtained values.

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    TABULAR COLUMN:

    S.No. Input Voltage(V in)

    Firingangle in

    Degrees

    Output voltage (V0) Output Current (I0)

    Theoretical Practical Theoretical Practical

    MODULE CALCULATIONS:

    For R-L Load: For R Load:

    V0 = (22V/) * Cos V0 = (2V/) * (1+Cos)

    I0 = (22V/R) * Cos I0 = (2V /R) * (1+Cos)

    = Firing Angle

    V = RMS Value across transformer output

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    MODEL GRAPH:

    Fig: out put wave forms for < 900

    RESULT:

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    DC JONES CHOPPER

    AIM: To study the related output wave forms of DC JONES CHOPPER with R & RL loads.

    Apparatus required:

    S.No. Name of the equipment Range Qty01 DC JONES CHOPPER power circuit

    and firing circuit- 01

    02 C.R.O. with deferential module - 0103 Patch chords and C.R.O. probes - Adequate04 Regulated dc power supply 30V/5A 0105 Variable Rheostat 0-200 / 5A 0106 Inductor 0-50-150 mH / 5A 0107 DC Voltmeter 0-100V 0108 DC Ammeter 0-5A 01

    CIRCUIT DIAGRAM:

    PROCEDURE:

    1. Make all connections as per the circuit diagram

    2. Give the DC power supply 10V to the terminal pins located in the power circuit

    3. Connect firing pulses from firing circuit to Thyristors as indication in circuit

    4. Connect resistive load 200 / 5A to load terminals and switch ON the MCB and IRS switch

    and trigger output ON switch.

    5. By varying the frequency and duty cycle, observe related waveforms

    6. Measure output voltage and current by connecting DC voltmeter & Ammeter

    7. Observe waveforms and readings, changing the frequency and duty cycle, and Tabulate

    all readings

    8. Calculate the output voltage and current by theoretically and compare with it practically

    obtained values.

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    TABULAR COLUMN:

    S.NO VIN TON TOFF

    DUTY CYCLE

    = TON/ T VO IO

    MODULE CALCULATIONS:

    VO = * VIN

    IO = VO / R

    MODEL GRAPH:

    RESULT:

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    SERIES INVERTER

    AIM: To study the series inverter.

    Apparatus required:

    S.No. Name of the equipment Range Qty01 Series inverterpower circuit and firingcircuit

    - 01

    02 CRO with deferential module - 0103 Patch chords and probes - Adequate04 Regulated dc power supply 30V/5A 0105 Variable Rheostat 0-200 / 5A 0106 Inductor 0-50-150 mH / 5A 01

    CIRCUIT DIAGRAM:

    PROCEDURE:

    1. Make all connections as per the circuit diagram

    2. Give the DC power supply 30V to the terminal pins located in the power circuit

    3. Connect firing pulses from firing circuit to Thyristors as indication in circuit

    4. Connect resistive load 200 / 5A to load terminals and switch ON the MCB and IRS switch

    and trigger output ON switch.

    5. By varying the frequency pot, observe related waveforms

    6. If the inverter frequency is increases above the resonant frequency of the power circuit

    commutation fails. Then switch OFF the DC supply , reduce the inverter frequency and try

    again.

    7. Repeat the above same procedure for different value of L,C load and also above the wave

    forms with and without fly wheel diodes.

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    8. Total out put wave forms entirely depends on the load, and after getting the perfect

    wave forms increase the input supply voltage up to 30V and follow the above procedure.

    9. Switch OFF the DC supply first and then Switch OFF the inverter.( Switch OFF the trigger

    pulses will lead to short circuit)

    fo = 1/21/LC-(R/L)2

    MODEL GRAPH:

    RESULT:

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    THREE PHASE HALF CONTROLLED BRIDGE CONVERTER

    Aim: To study the three phase half controlled bridge converter with R & RL Load.

    Apparatus required:

    S.No. Name of the equipment Range Qty01 Three phase half controlled

    bridge converter power circuitand firing circuit

    - 01

    02 CRO with deferential module - 0103 Patch chords and probes - Adequate04 Isolation Transformer 415V / 5A

    (with tapings)01

    05 Variable Rheostat 0-200 / 5A 0106 Inductor 0-50-150 mH / 5A 0107 DC Voltmeter 0-300V 0108 DC Ammeter 0-5A 01

    CIRCUIT DIAGRAM:

    PROCEDURE:

    1. Make all connections as per the circuit diagram

    2. Connect firstly 30V AC supply from Isolation Transformer to circuit

    3. Connect resistive load 200 / 5A to load terminals and switch ON the MCB

    4. Observe waveforms in CRO, across load and device in three phase half controlled

    bridge converter.

    5. By varying firing angle gradually up to 1800 and observe related waveforms

    6. Measure output voltage and current by connecting DC voltmeter & Ammeter

    7. Now increase the input supply voltage by changing tapping at Isolation Transformer.

    Observe waveforms and readings, changing the supply voltage up to 230V. Tabulate

    all readings at various angles and various voltages.

    8. For RL Load connect a large inductance load in series with Resistance and observe all

    waveforms and readings as same as above.

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    9. Observe the various waveforms at deferent points in circuit by varying the Resistive

    Load and Inductive Load.

    10. Calculate the output voltage and current by theoretically and compare with it

    practically obtained values.

    TABULAR COLUMN:

    S.No. Input Voltage(V in)

    Firingangle inDegrees

    Output voltage (V0) Output Current (I0)

    Theoretical Practical Theoretical Practical

    MODULE CALCULATIONS:

    V0 = (32V /2) * (1+Cos)

    I0 = (32V /2R) * (1+Cos )

    = Firing AngleV = RMS Value across transformer output

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    MODEL GRAPH:

    RESULT:

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    SINGLE PHASE A.C. VOLTAGE CONTROLLER

    Aim: To study the single phase AC voltage controller with R & RL Load.

    Apparatus required:

    S.No. Name of the equipment Range Qty01 Single phase AC voltage

    controller power circuit and firingcircuit

    - 01

    02 CRO with deferential module - 0103 Patch chords and probes - Adequate04 Isolation Transformer 230V / 5A 0105 Variable Rheostat 0-200 / 5A 0106 Inductor 0-50-150 mH / 5A 0107 AC Voltmeter 0-300V 0108 AC Ammeter 0-5A 01

    CIRCUIT DIAGRAM:

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    PROCEDURE:

    AC voltage controller with two thyristors:

    1. Make all connections as per the circuit diagram

    2. Connect firstly 30V AC supply from Isolation Transformer to circuit

    3. Connect firing pulses from firing circuit to Thyristors as indication in circuit

    4. Connect resistive load 200 / 5A to load terminals and switch ON the MCB and IRS

    switch and trigger output ON switch.

    5. Observe waveforms in CRO, across load by varying firing angle gradually up to 1800.

    6. Measure output voltage and current by connecting AC voltmeter & Ammeter

    7. Tabulate all readings for various firing angles.

    8. For RL Load connect a large inductance load in series with Resistance and observe all

    waveforms and readings as same as above.

    9. Observe the various waveforms at different points in circuit by varying the Resistive

    Load and Inductive Load.

    10. Calculate the output voltage and current by theoretically and compare with itpractically obtained values.

    A.C. voltage controller with TRIAC:

    1. Make all connections as per the circuit diagram

    2. Connect firstly 30V AC supply from Isolation Transformer to circuit

    3. Connect firing pulse from firing circuit to TRIAC as indication in circuit4. Connect resistive load 200 / 5A to load terminals and switch ON the MCB and IRS

    switch and trigger output ON switch.

    5. Observe waveforms in CRO, across load by varying firing angle gradually up to 1800.

    6. Measure output voltage and current by connecting AC voltmeter & Ammeter

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    7. Tabulate all readings for various firing angles.

    8. For RL Load connect a large inductance load in series with Resistance and observe all

    waveforms and readings as same as above.

    9. Observe the various waveforms at different points in circuit by varying the Resistive

    Load and Inductive Load.

    10. Calculate the output voltage and current by theoretically and compare with itpractically obtained values.

    TABULAR COLUMN:

    S.No. Input Voltage(V in)

    Firingangle inDegrees

    Output voltage (V0r) Output Current (I0r)

    Theoretical Practical Theoretical Practical

    MODULE CALCULATIONS:

    V0r = (V / ) * [(-) +{(sin2)/2} ]I0r = V0r/R

    = Firing Angle

    V = RMS Value across transformer output

    MODEL GRAPHS:

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    Fig: Voltage controller with R-load

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    RESULT:

    SINGLE PHASE CYCLOCONVERTER

    AIM: To study the single phase Cyclo converter with R & RL Load.

    Apparatus required:

    S.No. Name of the equipment Range Qty01 Single phase Cyclo converterpower circuit and firing circuit

    - 01

    02 CRO with deferential module - 0103 Patch chords and probes - Adequate04 Isolation Transformer (centre-

    tapped )230V-0-230V / 5A(with tappings)

    01

    05 Variable Rheostat 0-200 / 5A 0106 Inductor 0-50-150 mH / 5A 0107 AC Voltmeter 0-300V 0108 AC Ammeter 0-5A 01

    CIRCUIT DIAGRAM:

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    PROCEDURE:

    1. Make all connections as per the circuit diagram

    2. Connect firstly (30V-0-30V) AC supply from Isolation Transformer to circuit

    3. Connect firing pulses from firing circuit to Thyristors as indication in circuit

    4. Connect resistive load 200 / 5A to load terminals.

    5. Set the frequency division switch to (2,3,4,9) your required output frequency.

    6. Switch ON the MCB and IRS switch and trigger output ON switch.

    7. Observe waveforms in CRO, across load by varying firing angle gradually up to 1800

    and also for various frequency divisions(2,3,4,9).

    8. Measure output voltage and current by connecting AC voltmeter & Ammeter

    9. Tabulate all readings for various firing angles.

    10. For RL Load connect a large inductance load in series with Resistance and observe all

    waveforms and readings as same as above.

    11. Observe the various waveforms at different points in circuit by varying the Resistive

    Load and Inductive Load.

    12. Calculate the output voltage and current by theoretically and compare with it

    practically obtained values.

    TABULAR COLUMN:

    Sl.No

    InputVoltage

    (V in)

    Firingangle inDegrees

    FrequencyDivision

    V o

    (V)

    I o

    (A)

    Inputfrequency

    fs

    Outputfrequency

    fo

    fo / fs

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    MODULE CALCULATIONS:

    V0r = (V / ) * [(-) +{(sin2)/2} ]I0r = V0r/R

    = Firing Angle

    V = RMS Value across transformer output

    MODEL GRAPH:

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    RESULT:

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    STUDY OF SCR CHARACTERISTICS

    AIM: To study the V-I Characteristics of SCR. Finding the value of Latching current, Holding

    current, Gate voltage and gate current.

    Apparatus required:

    S.No. Name of the equipment Range Qty01 SCR characteristics Trainer - 01

    02 Patch chords - Adequate03 DC Voltmeter 0V-20V

    0V-50V0101

    04 DC Ammeter 0-25mA0-500mA

    0101

    CIRCUIT DIAGRAM:

    PROCEDURE:

    V-I CHARACTERISTICS:-

    1. Make all connections as per the circuit diagram.

    2. Initially keep V1 & V2 at minimum position and R1 & R2 maximum position.

    3. Adjust Gate current Ig to some constant(2.5/5.0mA) by varying the V1 or R1.

    4. Now slowly vary V2 and observe Anode to Cathode voltage VAK and Anode current IA.

    5. Tabulate the readings of Anode to Cathode voltage VAK and Anode current IA.

    6. Repeat the above procedure for different Gate current Ig.

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    GATE TRIGGRING AND FINDING VG AND IG:-

    1. Keep all positions at minimum.

    2. Set Anode to Cathode voltage VAK to some volts say 15V.

    3. Now slowly vary the V1 voltage till the SCR triggers and note down the reading of gate

    current(IG) and Gate Cathode voltage(VGK) and rise of anode current IA

    4. Repeat the same for different Anode to Cathode voltage and find VAK and IG values.

    TO FIND LATCHING CURRENT:-

    1. Keep R2 at middle position.

    2. Apply 20V to the Anode to cathode by varying V2

    3. Rise the Vg voltage by varying V1 till the device turns ON indicated by sudden rise in IA .

    At what current SCR trigger it is the minimum gate current required to turn ON the SCR.

    4. Now set R2 at maximum position, then SCR turns OFF, if it is not turned off reduce V2 up

    to turn off the device and put the gate voltage.

    5. Now decrease the R2 slowly, to increase the Anode current gradually in steps.

    6. At each and every step, put OFF and ON the gate voltage switches V1. If the Anode

    current is greater than the latching current of the device, the device says ON even after

    switch OFF S1, otherwise device goes to blocking mode as soon as the gate switch is put

    OFF.

    7. If IA>IL then, the device remains in ON state and note that anode current as latching

    current.

    8. Take small steps to get accurate latching current value.

    TO FIND HOLDING CURRENT:-

    1. Now increase load current from latching current level by varying R2 & V2

    2. Switch OFF the gate voltage switch S1 permanently (now the device is in ON state)

    3. Now increase load resistance(R2), so that anode current reducing, at some anode current

    the device goes to turn off .Note that anode current as holding current.

    4. Take small steps to get accurate holding current value.

    5. Observe that IH

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    VAK = (Volts)VGK = V IG= A

    MODEL GRAPH:

    RESULT:

    IG= AVAK (Volts) IA (Amps)

    VAK = (Volts)VGK = V IG= A

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    STUDY OF MOSFET CHARACTERISTICS

    AIM: To study the Output and Transfer Characteristics of MOSFET.

    Apparatus required:

    S.No. Name of the equipment Range Qty01 MOSFET characteristics Trainer - 01

    02 Patch chords - Adequate03 DC Voltmeter 0V-20V

    0V-50V0101

    04 DC Ammeter 0-500mA 01

    CIRCUIT DIAGRAM:

    PROCEDURE:

    TRANSFER CHARACTERISTICS:

    1. Make all connections as per the circuit diagram.

    2. Initially keep V1 & V2 at minimum position and R1 & R2 middle position.

    3. Set VDS to some say 10V.

    4. Slowly vary Gate source voltage VGS by varying V1.

    5. Note down ID and VGS readings for each step.

    6. Repeat above procedure for 20V & 30V of VDS. Draw Graph between ID & VGS.

    OUTPUT CHARACTERISTICS:

    1. Initially set VGS to some value say 3V by varying V1.

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    2. Slowly vary V2 and note down ID and VDS

    3. At particular value of VGS there a pinch off voltage between drain and source.

    If VDS< VP device works in the constant resistance region and IO is directly proportional

    to VDS. If VDS>VP device works in the constant current region.

    4. Repeat above procedure for different values of VGS and draw graph between IDVSVDS.

    TABULAR COLUMN:

    VGS = V

    VDS (Volts) ID (Amps)

    VDS= (Volts)

    VGS (V) ID(A)

    MODEL GRAPH:

    Fig: Transfer Characteristics fig: Output Characteristics

    VGS = VVDS (Volts) ID (Amps)

    VDS = (Volts)

    VGS (V) ID(A)

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    RESULT:

    STUDY OF IGBT CHARACTERISTICS

    AIM: To study the Output and Transfer Characteristics of IGBT.Apparatus required:

    S.No. Name of the equipment Range Qty01 IGBT characteristics Trainer - 01

    02 Patch chords - Adequate03 DC Voltmeter 0V-20V

    0V-50V0101

    04 DC Ammeter 0-500mA 01

    CIRCUIT DIAGRAM:

    PROCEDURE:

    TRANSFER CHARACTERISTICS:

    1. Make all connections as per the circuit diagram.

    2. Initially keep V1 & V2 at minimum position and R1 & R2 middle position.

    3. Set VCE to some say 10V.

    4. Slowly vary Gate Emitter voltage VGE by varying V1.

    5. Note down IC and VGE readings for each step.

    6. Repeat above procedure for 20V & 25V of VDS. Draw Graph between ID & VGS.

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    OUTPUT CHARACTERISTICS:

    1. Initially set VGE to some value say 5V by varying V1.

    2. Slowly vary V2 and note down IC and VCE readings.

    3. At particular value of VGS there a pinch off voltage VP between Collector and Emitter.

    If VCE< VP device works in the constant resistance region and IC is directly proportionalto VCE. If VCE>VP device works in the constant current region.

    4. Repeat above procedure for different values of VGE and draw graph between ICVSVGE.

    TABULAR COLUMN:

    VCE = VVGE (Volts) IC (Amps)

    VGE= (Volts)VCE (V) IC(A)

    MODEL GRAPH:

    Fig: Transfer Characteristics fig: Output Characteristics

    VCE =VVGE (Volts) IC (Amps)

    VGE = (Volts)VCE (V) IC(A)

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    RESULT:

    R-C TRIGGERING

    AIM:To study the Resistance-capacitance (RC) Triggering circuit of SCR.

    APPARATUS REQUIRED:

    S.No. Name of the equipment Range Qty

    01 Resistance-Capacitance Firing Circuit - 01

    02 Patch chords - Adequate03 CRO with differential module - 01

    04 R-Load 0-200/2A 01

    CIRCUIT DIAGRAM:

    PROCEDURE:

    1. Make all connections as per the circuit diagram.

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    2. Give the AC Power supply 20V/1A from the source indicated in the front panel.

    3. Connect Load i.e., Rheostat of 200 between two points.

    4. Switch ON Power supply and observe the wave forms of Input & Output at a time

    in the CRO.CH-1&CH-2

    5. Slowly vary the control Resistor RC, that Firing angle can vary from 0-180.

    6. Observe various voltage waveforms across load, SCR and other points, by varying theLoad Resistance and Firing RC part.

    7. Compare practical obtained voltage waveform with theoretical waveform and observe the

    Firing angle in R-C Triggering.

    Model graph:

    RESULT:

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    RESISTANCE TRIGGERING

    AIM:To study the Resistance Triggering circuit of SCR.

    APPARATUS REQUIRED:

    S.No. Name of the equipment Range Qty

    01 Resistance Firing Circuit - 01

    02 Patch chords - Adequate03 CRO with differential module - 01

    04 R-Load 0-200/2A 01

    CIRCUIT DIAGRAM:

    PROCEDURE:

    1. Make all connections as per the circuit diagram.

    2. Give the AC Power supply 20V/1A from the source indicated in the front panel.

    3. Connect Load i.e., Rheostat of 200 between two points.

    4. Switch ON Power supply and observe the wave forms of Input & Output at a time

    in the CRO.CH-1&CH-2

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    UJT TRIGGERING

    AIM: To study Firing of SCR using UJT Relaxation Oscillator and also to study UJT RelaxationOscillator in unsynchronized mode

    APPARATUS REQUIRED:

    S.No. Name of the equipment Range Qty

    01 UJT FIRING CIRCUIT - 01

    02 Patch chords & Probes - Adequate

    03 CRO with differential module - 0104 R-Load 0-200/2A 01

    CIRCUIT DIAGRAM:

    PROCEDURE:

    1. First observe the waveforms at different points in circuit and also trigger output T1 and

    T1` observe the pulses are synchronized.

    2. Now make the connections as per circuit using AC source, UJT Relaxation Oscillator,

    SCRs and Loads.

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    3. Observe the waveforms across the load and SCR and other points, by varying the variable

    resistor Rc and resistance load, observe firing angle of SCR.

    4. Use differential module for observing two waveforms (input and output) simultaneously in

    channel 1 and channel 2.

    5. Check the waveforms for large value of RC and small value of RC and also triggering

    points of SCR.FOR RELAXATION OSCILLATOR:

    1. Short the CF capacitor to the diode bridge rectifier to get filtered AC Output.

    2. We get equidistance pulses at the output of pulse transformer.

    3. The frequency of pulse can be varied by varying the potentiometer.

    4. Observe that capacitor charging and discharging time periods and calculate frequency

    and RC time constant of UJT Relaxation Oscillator by using given formulas.

    MODEL GRAPH:

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    RESULT:

    SPEED CONTROL OF THREE PHASE WOUND INDUCTION MOTOR

    AIM: To control the speed of three phase wound rotor induction motor.

    APPARATUS REQUIRED:

    S.No. Name of the equipment Range Qty

    01 Chopper module - 01

    02 Patch chords & Probes - Adequate03 CRO - 01

    04 R-Load 0-50/2A 01

    05 3 phase auto transformer 415V/10A 01

    06 3 phase wound rotor induction motor -- 01

    CIRCUIT DIAGRAM:

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    PROCEDURE:

    1. Make Power circuit connections as shown in the circuit diagram.

    2. Give 3 phase supply to the wound rotor induction motor, through 3 phase auto

    transformer.

    3. Now, the rotor terminals(R,Y,B) of induction motor is connected to the respective

    terminals(R,Y,B) of motor control unit.

    4. Connect the load rheostat (50 ohm) across load terminals and also CRO probe.

    5. Keeping duty cycle knob at minimum position switch on the chopper firing circuit.

    6. Keeping auto transformer at minimum position switch on the 3 phase mains. Switch on

    the chopper power circuit using 3 phase MCB.

    7. Increase the auto transformer voltage slowly(up to 30% of auto T/F output ) for suitable

    value such that motor rotates

    8. Vary duty cycle of the chopper firing circuit in steps and note down corresponding rpm.

    9. Plot a graph of duty cycle against speed.

    TABULAR COLUMN:

    Sl.No Duty cycle

    In %

    Speed in RPM

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    MODEL GRAPH:

    RESULT:

    CLOSED LOOP SPEED CONTROL OF 1HP DC MOTOR

    AIM: To control the speed of the DC motor using thyristorised converter unit.

    APPARATUS REQUIRED:

    S.No. Name of the equipment Range Qty

    01 Thyristorised drive for DC motor. - 01

    02 Patch chords & Probes - Adequate03 CRO - 01

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    04 Isolation transformer(With tappings) - 01

    05 1hp DC motor -- 01

    CIRCUIT DIAGRAM:

    PROCEDURE:

    1. Connect DC motor field & armature terminals to respective points in the power circuit and

    speed sensor to feedback terminals socket. Connect the volt meter & ammeter to the

    respective points.

    2. Circuit connections are made as shown in the circuit diagram.

    3. Check the connections and conform the connections made are correct before switching on

    mains supply.

    4. Keeping all the knobs at minimum position.

    5. Keeping PID controllers switches ON (down ward) position.6. Switch ON the field supply to the motor.

    7. Switch ON the firing controller power supply switch.

    8. Set the rpm to suitable value (say 800 rpm) and switch ON the power circuit.

    9. Using P,I,D knobs adjust the running rpm to set rpm by varying P gain, I timing , D gain.

    10. Load the motor up to 3-4A (in steps of 1A)and note down the speed for each

    step.Observe the current & voltage wave forms using CRO.

    11.Slowly reduce the load, set rpm to minimum value, Switch off MCB. Switch off the

    triggering circuit, Switch off field supply & remove the connections.

    TABULAR COLUMN:

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    Set RPM=800 rpm Set RPM=1000 rpm

    MODEL GRAPH:

    Sl.No Load

    current

    Running RPM

    Sl.No Load

    current

    Running RPM

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    RESULT:

    SINGLE PHASE DUAL CONVERTERAIM: To study the dual converter with R & L load.

    APPARATUS REQUIRED:

    S.No. Name of the equipment Range Qty01 Single phase dual converter.(power

    circuit & firing circuit.)- 01

    02 Patch chords & Probes - Adequate03 CRO - 01

    04 Isolation transformer(With tappings) - 0105 R load 0-200 ohm / 5A 0106 L load(center tapped) 300-0-300mH/5A 01

    CIRCUIT DIAGRAM:

    NON- CIRCULATING CURRENT MODE:

    CIRCULATING CURRENT MODE:

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    PROCEDURE:

    NON- CIRCULATING CURRENT MODE:

    1. Make all connections as per the non circulatory circuit diagram.

    2. Connect R-load across load terminals.

    3. Connect the input AC supply to the power circuit through an Isolating Transformer(take

    input voltage 30V)

    4. Select the NCC mode in firing circuit.

    5. Give the firing pulses and keep P-converter in ON position and also put on the MCB

    switch.

    6. By varying the firing angle observe related out put waveforms in the CRO.Tabulate all the

    readings.

    7. Repeat all above procedure for RL-load.

    CIRCULATING CURRENT MODE:

    1. Make all connections as per the circulatory circuit diagram.

    2. Connect R-load across load terminals.

    3. Connect the input AC supply to the power circuit through an Isolating Transformer(take

    input voltage 30V)

    4. Select the CC mode in firing circuit.

    5. Give the firing pulses and keep P-converter in ON position and also put on the MCB

    switch.

    6. By varying the firing angle observe related out put waveforms in the CRO.Tabulate all the

    readings.

    7. Repeat all above procedure for RL-load.

    TABULAR COLUMN:

    S.No. Input Voltage(V in)

    Firingangle inDegrees

    Output voltage (V0) Output Current (I0)

    Theoretical Practical Theoretical Practical

    MODULE CALCULATIONS:

    V0 = (22V / ) * (Cos1)

    I0 = (22V / Z) * (Cos1)

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    = Firing Angle

    V = RMS Value across transformer output

    MODEL GRAPH:

    RESULT: The single phase dual converter with R & RL load is studied.

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    PARALLEL INVERTER

    AIM: To study the parallel inverter.

    APPARATUS REQUIRED:

    S.No. Name of the equipment Range Qty01 Parallel inverter circuit. - 01

    02 Patch chords & Probes - Adequate03 CRO - 0104 Regulated power supply 30V/5A 0105 R load 0-200 ohm / 5A 01

    CIRCUIT DIAGRAM:

    PRCEDURE:

    1. Make all connections as per the circuit, and give regulated power supply 30V/5A.

    2. Give trigger pulses from firing circuit to gate and cathode of SCRs T1 & T2.

    3. Set input voltage 15V, connect load across load terminals.

    4. Now switch ON the DC supply, switch ON the trigger output pulses.

    5. Observe the output voltage waveforms across load by varying the frequency pot.

    6. Repeat the above same procedure for different value of L,C load values.

    7. Switch off the DC supply first and then switch off the inverter.

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    (switch off the trigger pulses will lead to short circuit)

    MODEL GRAPH:

    RESULT: