8. Calculate by using equation 4.1. 9. Measure Vdc with multimeter and compare results. (4.1)
24 Figure 4.1 Schematic diagram of half wave controlled rectifier 4.1.1 Calculations
25 4.1.2 Observations Table 4.1 Observations S .No Angle α Calculated Measured Error 1 2 3 4 5 6 7 4.1.3 Input and Output waveforms Figure 4.2 Input and Output Waveform
26 4.1.4 Conclusion 4.2 Study and perform single phase full wave controlled rectifier. 1. Construct the circuit on bread board which is shown in Fig 4.3. 2. Identify primary and secondary windings of transformer with the help of multimeter. 3. Connect secondary winding of transformer at the input of circuit. 4. Apply 220V AC to primary winding of transformer. 5. Connect oscilloscope across RL. 6. Observe the output wave form and measure angle. 7. By varying variable resistor adjust different firing angles measure the average output voltages with the help of oscilloscope. 8. Calculate by using equation 4.2. 9. Measure Vdc with multimeter and compare results. (4.2) Figure 4.3 Schematic diagram of full wave controlled rectifier
27 4.2.1 Calculations 4.2.2 Observations Table 4.2 Observations S .No Angle α Calculated Measured Error 1 2 3 4 5 6 7
28 4.3.3 Input and Output waveforms Figure 4.4 Input and Output Waveform 4.3.4 Conclusion
29 EXPERIMENT 5 Main’s synchronized gate firing circuit Objective 1. To study and perform main‟s synchronized gate firing circuit of an SCR. Equipment Required 1- Digital Multimeter 2- Oscilloscope 3- Transformer 12V 4- Silicon Controlled Rectifier (SCR) 5- Diode 1N4007 6- Resistors (470Ω, 1kΩ, 10kΩ, 1MΩ) 7- Variable Resistor (5kΩ) 8- Capacitors (100nF, 1000uF) 9- Transistors (TIP122, C1383) 10- Fuse 200mA 11- Connecting wires 12- Breadboard 5.1 Theoretical background In this lab a pulse width modulation gate firing circuit is studied that takes dc input and accordingly generate gate firing pulses for an SCR. One of the main component of this circuit is the synchronization of gate firing pulses with the main‟s power driving the SCR. Block diagram of complete system is shown in Fig 5.1. Figure 5.1 Block diagram of complete system
30 5.2 Procedure1. Identify primary and secondary windings of transformer with the help of multimeter. 2. Connect primary winding of transformer to main supply and secondary winding to the input of bridge rectifier as shown in Fig 5.2. 3. Connect oscilloscope across secondary winding and RL. 4. Apply 220V ac at primary winding of transformer. 5. Observe and analyze input and output wave forms with oscilloscope. 6. Construct zero crossing detector circuit on bread board as shown in Fig 5.4. 7. Connect output of bridge rectifier with the input of zero crossing detector. 8. Common the ground terminal of both circuits. 9. At Vcc terminal we got smooth DC voltages that will be used to provide supply to integrator circuit. 10. Connect oscilloscope between point B and ground. 11. Observe and analyze output of zero crossing detector with oscilloscope. 12. Construct operational amplifier based integrator circuit on bread board as shown in Fig5.6. 13. Connect output of zero crossing detector with the input of integrator. 14. Connect Vcc from zero crossing circuit to the Vcc pin of operational amplifier.
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- Spring '17
- Rizwan Khan