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# Electrical Engineering

### Transfer Function and Feedback Control System

An open loop transfer function of a certain unit feedback control system is described as below, where K is an adjustable gain (Proportional Controller) and G(s) is a process transfer function. 1. In the space provided (see attached), sketch a Root Locus plot of the closed loop system for positive Proportional Controller gain

### Proportional-Rate Feedback Control System

Consider the block diagram in Figure Q3.1, describing the process from Question 2, under Proportional-Rate Feedback control (see attached). 1. Find a closed loop system transfer function in terms of controller gains, Kp, Kd. 2. Find the values of gains Kp, Kd such that the resulting Percent Overshoot of the closed loop s

### Control Systems with Complex Poles

Consider five different control systems, with descriptions below. Which system will have the slowest rise time? (see attached) System 1: Two complex poles at -10 -j5, -10 +j5; System 2: Two complex poles at -10 -j5, -10 +j5 and a zero at +2; System 3: Two real poles at -10, -3; System 4: Two complex poles at: -10 -j5, -10

### Communications Systems

Please refer to the attached file. It may contain more than one-page. A PCM system with uniform quantization is used to transmit a speech signal. The bandwidth of the signal is equal to 6 KHz. At the receiver we require an SNR in the reconstructed signal equal to 40 dB. a) What is the minimum sampling rate for the speech

### Transistor Saturation

For the circuit of the figure attached, determine the required values of Rd, R1 and R2 so that the transistor operates in the saturation region with Id=0.5mA and Vd=3V. The enhancement mode PMOS transistor has Vt=-1V and K=0.5mAV^-2. What is the largest value Rd can have while maintaining the transistor in saturation?

### Bipolar Junction Transistor

A silicon n-p-n bipolar junction transistor is designed with emitter, base and collector doping levels of 10^19cm, 10^15cm and 5*10^17cm, respectively. Assuming the intrinsic carrier concentration (ni) in silicon to be 10^10cm, calculate the Fermi Energy, Ef, relative to the intrinsic energy scale clearly to show the relative po

### Block Diagram Reduction

First Problem: 1. Find TY/R. 2. Find TU/d Second Problem: a) Find TY/R for the following system.

Consider a transient response of a control system as shown in the attached figure. Choose which system description matches this response. a) DC gain 2, pole at -2, -3, -4. b) DC gain 2, pole at -1-j4.4, -1+j4.4. c) DC gain 1, pole at -1-j4.4, -1+j4.4. d) DC gain 1, pole at -10. e) DC gain 2, pole at -10, -2, zero at +5.

### Proportional-Rate Feedback Control

Consider the block diagram in the attached figure Q3.1, describing the process under Proportional-Rate Feedback control. 1) Find a closed loop system transfer function in terms of controller gains, Kp, Kd. 2) Find the value gains Kp,Kd such that the resulting Percent Overshoot of the closed loop step response will be equal

### Control Systems - Proportional-Integral-Derivative Controlled Process and Nyquist Plots

Consider the block diagram attached, describing a process under Proportional-Integral-Derivative control. 1) Is the system open loop stable? Justify your answer 2) Let Ki = 10. Use the Routh-Hurwitz criterion to find the range of Kd, and Kp in terms of Kd, so that closed loop stability is achieved. 3) Suppose that Ki =

### Matched Filter Theory

Find the impulse response of a filter matched to the signal in the attached problem. 1 Find the impulse response of a filter matched to the signal . Assume

### Control Systems: PID Controller

Which one of the following statements regarding the operation of a PID controller is definately false? - Higher Proportional gains improve steady-state error performance. - If the system operates in a noisy industrial environment, PID control is recommended - Higher Integral gains may result in the system becoming unstable

### Controller Configurations in Control Systems

Consider the responses of a closed loop system under several types of control. Choose the controller configuration that would result in the response following the dashed line trace on the plot. - Proportional Control - Lead Control - Proportional + Derivative Control - Lag Control - PID Control

### Control Systems: Operation of a PID

Which one of the following statement regarding to operation of a PID is true? - Lower proportional gains improve steady state error performance - Derivative action tends to slow down system rise time - Higher derivative gains filter out noise - High integral gains may saturate controller output and cause the windup effect -

### Control Systems - System Output

Please supply steps to correct answer: For a CLOSED LOOP unit feedback control system, if reference (R) is eqaul to 5 units, and forward path Gain (G) is equal to 10, then the system output (Y) must be: (a) 50 (b) 4.54 (c) 5 (d) 10/11 (e) 0.454

### Compute the Transfer Equation

The questions are for the equation: y"(t) + 6y'(t) + 34y(t) = 2x'(t) + 11x(t) a) Compute the transfer equation Y(s)/X(s). b) Compute the response of the system to the input x(t)=e^(-2t) u(t) assuming no initial stored energy. c) Compute the response of the system to the input x(t)=4t^2 * e^(-6t) u(t).

### Using the Ruth Hurwitz Criterion

Question: Find the values of k for the system in part a) and the values of alpha for part b). Please view the attachment file to see the full questions for parts a) and b).

### Nyquist Analysis Bode Plots

Given the Bode plot of open loop L(s)=..., (i) Make a sketch of the Nyquist diagram and determine the stability of the closed loop system with negative feedback.(ii)If the system is unstable... (See attachment for full questions)

### Substituting equation explanation

This is perhaps more of a mathematical question nonetheless, I'm unsure how (cant seem to arrive at the result) substituting equation 3-27 into 3-23 results in 3-28. Please see the attachment.

### Bode and Nyquist Diagram and Root Locus

Roughly sketch the Bode diagram, and hence the complete Nyquist diagram for: {see attached} Proportional control of the plant {see attached} in a standard negative feedback 2DOF structure (with an ideal sensor) is to be investigated {see attachment for questions}.

### Control Systems - Unity Feedback Loop, Nyquist Contour, Routh-Hurwitz Analysis

A process has a transfer function: {see attached} and is included in a unity feedback loop with a proportional controller Kp in a feedforward branch of the control loop. (a) Sketch a Nyquist contour for this system (b) Apply the Nyquist stability criterion to find a suitable range of K for stable closed loop system behaviour.

### Control Systems and Block Diagrams

Please refer to the attached file.

### Closed Loops and Root Locus

Consider the root locus for ... (*see attachments for function and diagram) i) Graphically, find the gain required to give dominant closed loop poles with ... (*see attachment for function) ii) For the above value of gain, find natural frequency and hence sketch the expected reference to output step response, assuming that the

In order to delimit messages from a stream of bits being exchanged on a data link, a sender marks the beginning and end of each message with a control flag. In order to prevent the receiver from inadvertently detecting the end of a message when a pattern in the data matches the control flag, the sender stuffs extra bits or chara

### Control Systems (Transfer Function; Open / Closed Loop System; Observable / Unobservable)

A system described in the attachment is under feedback control of the form u = Kx + r where r is the reference input. (i) Show that (A,C) is observable. (ii) Compute a K of the form {see attachment} so that (A - BK, C) is unobservable. (I.e., the closed loop system is unobservable) (iii) Find the transfer function of the open

### Control Systems, Amplifier Gain, Natural Frequency, Root Locus

Please consider the attached motor control system. (i) Find the characteristic equation of the closed loop system, and find the amplifier gain K1 so that the natural frequency of the system is {see attachment} (ii) Suppose that K2 = 1. Sketch the root locus of the closed loop system poles for {see attachment} (iii) For what v

### Negative Gain Root Locus

Consider a negative gain root locus for L (s) = k (s-1)/[s(s^2 + 4s + 8)] with a scale of 20mm = 1 unit. i. Graphically, find the gain required to give dominant closed loop poles with zeta = 0.5. ii. For the above value of gain, find natural frequency and hence sketch the expected reference to output step response, assuming

### Block diagram in feedback control system form

I attached a Word document with a circuit: a) Draw a block diagram of the circuit in feedback control system form. b) Derive an expression for Io in terms of Vi and the system parameters Av, Ro, RL, and Rf. c) How should the system be designed to make Io independent of RL? What is the approximate expression for Io in terms