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Learn about complex numbers, phasors, and their application in circuits. Explore Euler's formula, Cartesian and polar coordinates, and Phasor Analysis to solve circuits. Practice calculating magnitude and phase of complex numbers. Engage with video resources and discussions to enhance understanding.
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AppliedElectromagneticsEEE 161 Intro to Transmission Lines
Complex Numbers/Phasors at home reading • View the video about complex numbers: https://www.youtube.com/watch?v=T647CGsuOVU • View the phasor simulation: https://en.wikipedia.org/wiki/File:Circle_cos_sin.gif • Read chapter 1, sections on Complex numbers and phasors. • Post at least 1 “muddiest point” (most unclear) in this reading on the SacCT discussion Complex Numbers and Phasors. These are graded as extra credit. • Due Week 2, day before first class.
EEE 161 Week 1, Lecture 1, Video 1 Sinusoidal signals
Objective • In order to understand transmission lines we have to be able to describe sinusoidal signals first!
Motivation • Here is an equation of a wave • Here is an equation of a sinusoidal signal How are they the same and how are they different? Use vocabulary to name green and yellow highlights.
Sinusoidal Signal Describe this graph using at least 5 words!
EEE 161 Week 1, Lecture 1, Video 2 Complex Numbers
Objective • To solve simple circuits we have to be able to apply basic arithmetic operations with complex numbers.
Complex numbers Cartesian Coordinate System Polar Coordinate System For example: Euler’s Identity
Quiz • Complex number Z=3+j2 is given. • Sketch the number in Cartesian coordinate system • Find the magnitude and phase • Write a complete sentence to explain magnitude and phase on the diagram
Some concepts from complex #s Conjugate Division Addition It is easier to add/subtract complex numbers when they are in _____________ coordinates. It is easier to divide/multiply complex numbers when they are in polar coordinates.
Which equation do we use to go from Polar to Rectangular coordinates?
Euler’s equation A A A
QuizWhat is the real and imaginary part of the voltage whose amplitude is 2 and phase is 45 deg? (no calc)
Some more concepts Power and Square Root.
Quiz Calculate and sketch the magnitude and phase of the following three complex numbers:
Quiz Find the magnitude and phase of the following complex numbers:
Where did we see division of complex numbers?example in EE: Find magnitude and phase of the current in the circuit below How can we find magnitude and phase of this current in terms of variables R, L, V and ω?
EEE 161, Week 1, Lecture 1 Concepts: application of Complex numbers to circuits
Example 1 HW problem complex numbers
Example problem complex numbers Z1=5<-60, z2=4<45z1*z2=20<-15z1+z2=5.33-j1.55<-60=5*e^j(-60)Euler’s formula 5e^j(-60)=5(cos(-60)+jsin(-60))=5/2-j5*sqrt(3)/2 - cartesian
2. Example 2 HW problem complex numbers
2. Example problem homework 1 Z1=3-j2, Z2=-4+j3Polar form?Z1=sqrt(13)<arctg(-2/3)
3. Example problem how complex numbers are used in circuits • Find the magnitude and phase of the voltage on the mystery circuit if the current through it was measured to be • And the complex equation to find the voltage is
4. Sinusoidal Signals and Complex numbers relationship Sinusoidal signals can be represented using complex numbers!
5. Watch complex numbers video and post on discussion board https://www.youtube.com/watch?v=T647CGsuOVU Post on Week 1 Lecture 1 summary of what you have learned (or know really well) and at least one question that is still unclear. Respond to one other student.
Optional but interesting3Blue1Brown explains complex numbers (6min)https://www.youtube.com/watch?v=F_0yfvm0UoU
EEE 161 Week 1, Lecture 2, Video 1 Measurement Mystery
Interesting Case Study in an Electrical Engineering Laboratory Let’s look at two simple circuits
Dr. M is measuring voltage in the laboratory using her handy-dandy Fluke. She measures voltages on the resistors and inductor to be as shown. She is shocked with the measurement on top and bottom circuit. Why? What do you think she expects, and what did she measure?
EEE 161 Week 1, Lecture 2, Video 2 Process to solve circuits using phasors
Objective • Students will be able to solve simple circuits using phasors
EEE 161, Week 1, Lecture 2 Concept: phasors
Objective • Students will be able to solve a simple circuit using phasors
1. Socrative Quiz To use voltage divider eq the same current has to flow through both impedances.