R05312202-INDUSTRIAL-ELECTRONICS

8/7/2019 R05312202-INDUSTRIAL-ELECTRONICS

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Code No: R05312202 Set No. 1

III B.Tech I Semester Regular Examinations, November 2008INDUSTRIAL ELECTRONICS

(Instrumentation & Control Engineering)Time: 3 hours Max Marks: 80

Answer any FIVE QuestionsAll Questions carry equal marks

1. (a) Explain the concept of drift in transistor DC amplifier.

(b) Explain the working principle of a basic DC amplifier with the help of a neatdiagram. [8+8]

2. (a) What is meant by Load regulation?

(b) Give block schematic of series regulator circuit and explain its working.

(c) Explain the principle of basic shunt regulator circuit. [4+6+6]

3. (a) Sketch a regulator circuit that uses an LM 217 IC positive voltage regulatorand explain its working.

(b) Define short period and long period accuracy of a stabilizer. Give typicalvalues of these parameters. [8+8]

4. (a) List out the major applications of thyristors.(b) Explain the theory and operation of SCR using suitable figures.

(c) Draw the load voltage waveforms for thyristor circuit with DC input.[5+6+5]

5. (a) Draw the circuit and describe the working of a series inverter. Draw thewaveforms of various current and voltages involved?

(b) Write expressions for the frequency of output voltage and attenuation factorin the above circuit. [16]

6. Explain the schematic construction of the following:

(a) DIAC

(b) TRIAC. [8+8]

7. Draw the block diagram of digital timer counting unit and explain its operation.[16]

8. (a) Explain Thermal effects of ultrasonics?

(b) Describe dispersive and colloidal effects of ultrasonics? [8+8]

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1. (a) Draw a Darlington emitter follower circuit and derive the h-parameters forthis circuit.

(b) Discuss about stabilization in DC amplifier with the help of relevant circuit

diagrams. [8+8]

2. (a) Explain the series regulator using pre-regulator and Darlington pair.

(b) What are the different protection techniques used in regulated power supplies?[8+8]

3. (a) Differentiate between the linear and switched mode voltage regulators.

(b) Draw the block diagram of a servo controlled voltage stabilizer and explainabout each part in detail. [6+10]

4. (a) Explain the parallel operation of SCRs and define and derive string efficiency.

(b) Explain various protection methods for SCR. [8+8]

5. A series inverter has the following parameters: inductance L=12mH, C= 0.1 mi-croF, load resistance R=100 Ohms and Toff=0.3millisec. Determine

(a) the frequency of the output voltage and

(b) the attenuation factor. [8+8]

6. (a) What are the principal methods of varying the DC output voltage in DCchopper?

(b) Draw the circuit and describe the principle of operation of a type A singlequadrant DC chopper? [8+8]

7. Describe the principle of flash welding. Mention its main applications. [16]

8. (a) What is meant by Ultrasonics?

(b) Explain the generation of ultrasonic waves using magnetostriction effect?[6+10]

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1. (a) Explain the principle of operation of a Darlington emitter follower circuit andderive its gain.

(b) Draw the circuit diagram of a cascode transistor amplifier and explain its

working. [8+8]

2. Discuss in detail following protextion technious:

(a) Short circuit

(b) over vltage

(c) thermal protection. [6+6+4]

3. (a) Draw the circuit of monolithic IC regulator with variable output and currentlimiting features and explain it in detail.

(b) Draw a voltage regulator using LM 105 IC with an external pass transistorand explain its working. [8+8]

4. (a) Draw typical static V-I characteristics of a thyristor and explain its salientfeatures.

(b) Discuss about various commutation methods used in SCR circuits. [8+8]

5. Draw the circuit of single phase full wave controlled converter with freewheel diode.Describe its working and draw waveforms of various voltages and currents involved?

[16]

6. (a) What are the basic elements of a DC chopper? What are the characteristicsof ideal elements of DC chopper?

(b) Write about the principle of operation of a step-up DC chopper? [10+6]

7. (a) Give the classification of timers according to the technique used to achieve thetiming.

(b) Give the construction and describe the working of

i. simple bimetal strip timer and

ii. dual bimetal strip timer. [6+10]

8. Describe the following applications of dielectric heating:

(a) preheating of plastic performs

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(b) wood gluing

(c) food processing and(d) electronic sewing [4+4+4+4]

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1. (a) What is meant by stabilization? Discuss about various stabilization techniquesused in DC amplifiers.

(b) Discuss about ideal characteristics of an operational amplifier. [16]

2. (a) Compare series and shunt voltage regulators.

(b) Design a series voltage regulator with the following specifications: Vo = 20V,Vin = 22-30V, ILOAD = 50mA. [8+8]

3. Discuss the folowing in deail:

(a) Fixed and adhustable IC voltage Regulators.

(b) Current boosting. [10+6]

4. (a) What is meant by catastrophic failure and explain the protection techniques

that are used in thyristor circuits.

(b) Define gate power dissipations and explain its importance in SCR. [8+8]

5. (a) What are the requirements of a practical inverter?

(b) A series inverter operates under resonance condition at frequency of 4 KHz.The capacitance is 1microF, resistance is negligible, calculate the value ofinductance. [6+10]

6. (a) What are the merits and drawbacks of voltage commutated thyristor dc chop-per?

(b) Derive design expression for commutating capacitor C and commutating in-ductor L.

(c) Derive expressions for average load voltage V0, minimum and maximum loadvoltage. [4+6+6]

7. Describe the principle of spot welding and butt welding. What are their mainapplications? [16]

8. Describe the typical methods of coupling of electrodes to the R.F. generator fordielectric heating. [16]

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R05312202-INDUSTRIAL-ELECTRONICS