TUTORIAL

EKT 308Computer Network

Question 1

1. a) Differentiate between open loop and closed loop control systems. b) Explain positive features of feedback in a control system. c) Find poles and zeros of the overall transfer function of the system in Figure 1. What is the output if a unit step input is applied?

1. d)

2. Figurein circuit electrical for the)(/)()(function transfer overall theFind sEsIsG

Figure 2.

Question 22. a) Find the state differential equation for the system in Figure 3. b) Find output.

)(current inductor )( voltagecapacitor

2

1

tixtvx

L

c

Figure 3.

2. c) Find the stability of the following system

3. a) Define i) Rise time, ii) steady state error for a system for step input.

3. b) If K = 20, find steady state error for the following system for ramp input.

c) Steady state error for unit step.d) Find value of K for which percentage overshoot is 20% for unit step input.

Question 1i) A unity feedback system has the following open loop transfer

function,

)5)(3()1()()()(

ssssKsGsGsL c

Determine the range of K so that the closed loop system is stable.

ii) Sketch the root locus for the above system.

SECTION B

Question 2i) Consider the system in the following figure.

Sketch the root locus for the above system.

ii) Find minimum jeta for stable complex root.iii) Explain transfer function of a PID controller.

Question 3

frequency.crossover -phase Find ))2)(1(

)4(30)()()(

function, transfer loopopen following thehas which system afor diagram Bode Draw )

iisss

ssGsGsL

i

c

Question 4

unstable? system theis K, of aluesFor what v ii)system for the diagramNyquist Draw i)

)2()5()(

function, transfer loopopen following with thesystem controlfeedback aConsider

2

s

sKsOL

ii) Draw an RC circuit that would function as a lead-lag network.

Question 5

100.K Assume

degree. 60 ofmargin phase a provide will that system for thenetwork r compensato lag-phase aDesign

)4(

function, transfer loopopen following with thesystemfeedback unity aConsider i)

ssK