Compare SCR with IGBTs.
[3 marks]Draw input voltage, output voltage and output current waveform of half wave diode rectifier with RL load.
[4 marks]Develop two transistor analogy model of SCR. Explain working principle of SCR from it.
[7 marks]Explain construction of TRIACs.
[3 marks]How SCRs can be used as bidirectional switch?
[4 marks]Explain series and parallel operation of SCRs and problem associated with them.
[7 marks]Explain the requirement of gate drive.
[3 marks]Explain the term latching current and holding current of SCR. Compare them.
[4 marks]Discuss RC triggering circuit. Explain its limitations.
[7 marks]Explain principle of natural commutation.
[3 marks]Explain effect of gate current on V-Icharacteristics of SCR.
[4 marks]With the necessary circuit diagram and waveforms explain the operation of UJT triggering circuit.
[7 marks]Explain snubber circuit and its applications.
[3 marks]Explain applications of pulse transformer and optocouplers.
[4 marks]Sketch circuit diagram and waveform of 3-phase full wave fully controlled converter. Analyse its performance with RL load.
[7 marks]Explain requirement of di/dt and dv/dt protection of SCR.
[3 marks]Discuss need of freewheeling diode.
[4 marks]Sketch circuit diagram and waveform of 1-phase full wave bridge converter. Analyse its performance with RLE load.
[7 marks]Compare voltage commutated, current commutated and load commutated chopper.
[3 marks]Explain four quadrant operation of DC drives.
[4 marks]Explain operation of 3-phase separately excited DC drive controlled by semi converter.
[7 marks]Explain working principle of boost converter.
[3 marks]Explain four quadrant operation of chopper.
[4 marks]Explain the concept of regenerative breaking. Explain chopper controlled DC drive with regenerative breaking.
[7 marks]