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Electrical Engineering

PI Controller and Nyquist Analysis

(Complete problem with equations found in attachment). Problem 1 A very common industrial controller is the proportional and integral (PI) controller. It has a transfer function, , kp is the proportional gain, Ti is the "reset time" For an integrating process, P(s) = 2/s, investigate the positive root locus for

Wireless Network - Prorogation Delay

The attached 'power point' slide contains information (note most of the information may not be relevant but a few slides contain the relevant formulas) that should assist with solving the problem in the Word document (see attachments). Suppose propagation delay is alpha, Short Interframe Space (SIFS) is alpha, Distributed Int

Wireless Networks - Encoder Output

1) The figure attached shows the encoder for a ½ rate convolution code. Determine the encoder output produced by the message sequence 1011. Assume that the initial state of the encoder is zero. See attachment for image.

Speedup and Efficiency

Question: Given 100 processors for a computation with 5% of the code that cannot be paralleled, compute the speedup and efficiency.

Saturated NPN Transistor

A saturated npn transistor has a base to emitter applied voltage of 0.6V. The collector to emitter voltage is 0.2V. The collector current is 12mA. The beta value of the transistor is 30. What is the emitter current?

Important Information About RC Series Circuit

An RC series circuit has a voltage source of 10Vac, a resistor of 10ohms, and a capacitor with an impedance of -j10ohms. How do I find the magnitude and phase angle of the current flow through the capacitor?

Design a series controller

The process of a unity-feedback control system has the transfer function 100 Gp(s) = ------------------------ s^2 + 10 s + 100 Design a series controller (a PD, PI or PID) so that the following performance specifications are satisfied. Steady-state error due to a step i

Autocorrelation and Tao

I have a question from my ECE 302 class regarding the mean of a random process given a particular autocorrelation function in terms of tao. I know Variance=(mean-square)-(mean)^2 and I know that the (mean-square)=autocorrelation function with tao set to 0, but I don't know how to get the mean if I don't know the variance of

Transfer Function Analysis for a Unity Feedback System

For a unity feedback system with open-loop transfer function, G(s) = K(s+alpha)/(s^2 + 4s + 1): a) Find all values of alpha such that the system is stable for K = 2. b) If the unity feedback closes around this G(s) and an input is a unit step r(t) = 1u(t), what is the stead-state error, e_ss, as a function of alpha and K? c)

Thevenin Equivalent Voltage

A resistor, R, was connected to a circuit box as shown. The voltage, v, was measured. The resistor was changed, and the voltage was measured again. The results are shown in the table. Determine the Thevenin equivalent voltage vt of the circuit within the box. Determine the Thevenin equivalent resistance Rt of the circuit?

Linear Systems and Equilibrium Point

Consider the ping pong ball levitator shown in the attachment. Assume that a nozzle makes a cone of air with velocity V_air(h) = u(t) / (h + alpha)^2. u(t) is the opening of an air supply valve, h is the height above the nozzle and alpha is a constant. The drag force on the ball is f_up = c_d * A(v_air - v_ball)^2. "A" is the

Solving: Fourier Series

Compute the Fourier series coefficient of the periodic function shown in the figure(view attachment) and defined as: X(t) = A 0 <= t <= T/3 0 T/3 <= t < T

8 x 8 JPEG Image

Consider the following 8x8 8-bits image: 26 25 30 30 37 37 37 37 7 28 29 30 37 37 37 37 6 9 31 28 37 37 37 37 4 5 10 30 37 37 37 37 9 9 9

Phasor Current

Hi, I need some assistance for the following question: Question: For the following circuit, find the phasor current. Please see attachment for circuit diagram.

System Modelling (Output: Density)

Two tanks are arranged as shown in the attachment. Salt and water are added into the first tank at rates {see attachment}. The tanks are well mixed and the salt dissolves completely. The flow between the two tanks depends on the pressure difference {see attachment}. The flow out of te second tank is given by {see attachment}. Bo

System Modelling - Output and State Differential Equation

See the attached file. Consider the ice-cream manufacture process shown in the attachment. The ice-cream is made up of the following ingredients: i) Liquid (cream, milk, water etc.) added at a rate r1 [kg/hr] and with a density p1 [kg/1]. ... {see attachment for more details} (a) Find a model for the process with heigh

Steady State Conditions

Just before the switch is opened at t=0, the current through the inductor is 1.70 mA in the direction shown in figure (PLEASE SEE ATTACHMENT). Did steady-state conditions exist just before the switch was opened? L = 0.9 mH; R1 = 6k Ohm; R2 = 6k Ohm; R3 = 3k Ohm; Vs = 12V

Simulink - Modelling

Consider the following model of a cell growth in a bio-system. The state differential equation is... a) Identify the state variable, the inputs, outputs and parameters. (See attachment for full question)

Finding a transfer function

The frequency response of a linear time invariant system has been measured and can be seen in the attachment file below. A feedback element with a transfer function, H(s), is to be chosen so that the system steady-state error to a unit step input is equal to 0.07. What is a suitable transfer function to achieve this? I am ha

Internal Resistance of a Battery

The circuit is used to measure the internal impedance of a battery. The battery being tested as a NiMH battery cell. A fresh battery is being tested, and it is found that the voltage Vout, is 2.28 V with the switch open and 2.27 V with the switch closed. Find the internal resistance of the battery. See attached file f

Calculate the Per-Unit Current and Load Current in Amperes

Three zones of a single-phase circuit are identified in figure 3.10(a) {see the attachment}. The zones are connected by two transformers, T1 and T1, whose ratings are also shown in the same figure. Using the base values 20 kVa and 115 volts in zone-3, calculate the per-unit current and load current in amperes. Neglect the transf

Calculating Line Voltage at the Load

Two balanced, in parallel connected, three-phase loads are fed by a three-phase line with an impedance of (2+j4) Ohm per phase. Calculate the line voltage at the load, given the phase voltage and per-phase current. Please see the attached file for the four possible options and the adequate notation of the formulas.

Network Planning, Link Budget, and Hata Model

A Potential client has asked you to predict the number of cells necessary to cover 100 square miles. The area the client wished to cover compromises 5 sq miles Urban, 25 sq miles, Suburban and the remainder rural. For urban areas the client can acquire 30 m towers, for Suburban 60 m and for rural 100 m Assume feeder lengths =

Communications Systems of Frequency Downconverters

A frequency downconverter is implemented using a square-law device as follows. The band-pass filter has a center frequency fi=|fc - ft| (also known as the intermediate frequency, IF). Assume that the message bandwidth of the input signal m(t) is equal to B Hz. a) Determine the smallest possible IF frequency, so that there

Wireless Communication

1. For an urban environment, at 1900MHz, what is the path loss between a base station at 40m height and a mobile at 1.6m height separated by a distance of 5 km? 2. TDMA has 416 frequencies in one of the cellular license bands. If a cellular operator designs a network with a 5/15 reuse pattern, how many frequencies per cell

Root Locus and Root Locus Design

Please help me with the attached root locus design question (see attachment). (Involves: plotting the root locus, determining gain, designing a proportional and integral controller, determining the location of the controller zero, and finding the required controller gain).