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Serious Help Needed Please

  1. Jan 12, 2006 #1
    Serious Help Needed...!!! Please

    Hi, I am new to this forum....And I need some help here.

    I am in college and pursuing for eletrical engineering. and this is going to be my first semester to begin My major courses. I was trying to register for "Electric circuit I". But they didnt allowed me to take this course without taking "Differential Equation" . Either I had to take...differential equation before "eletric circuit I" or con-currently in the same semester.

    So I registered Diff Equation too few days ago. But..today I came to know..they cancelled Differntial Equation class because only 3 people registered for it.. And NOw I am in dire strait. So i need you help.

    Since I was going to take "eletric circuit I " in another college (cross registration)....They might still allow me to take "eletric circuit I"..Because they still think I am taking Differnential equation concurrently.

    So DO I really Need Differential Equation for Electric Circuit I???? Is Electric circuit Heavily Based on Differential Equation..or I can still go ahead and try it.?
    I am thinking of goin ahead and take Eletric circuit I ....without Diff Eqn.....Am I taking wrong desision??
    The main reason I am still going to take "Electric circuit I" is because..i dont have to pay...for this course (cross registration)..and I can save 1200$ here.
    Guys I need YOUr help..!!!
    If my decision i wrong I would take another course instead of Electric circuit I...which I will have to pay.

    Please anyone?
  2. jcsd
  3. Jan 12, 2006 #2

    Tom Mattson

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    If your circuits course is similar to the course of the same name offered at just about any university, then yes you will need to know certain facts about differential equations to get by in your course.

    I want you to re-read Section 2 of the Disclaimer at the top of the Academic and Career Guidance Forum before reading my response.

    *pause for you to read*

    Now, are you making the wrong decision? That depends on how much time and effort you are willing to spend doing independent study in differential equations to get up to speed. To get through electric circuits you will not need the entire diff eq course. If yours is a typical circuits course you will only need to know how to solve linear 1st and 2nd order equations by various methods, including Laplace transforms. You will also need to know some Fourier analysis.

    If you post your syllabus for circuits here, I will try to tell you what math you need to know before beginning each section.
  4. Jan 12, 2006 #3
    thanks a Lot... i have no words to thank you...
    here my course description....for Eletric Circuit I

    Course Description:
    Prerequisite or corequisite: ESC 250. Basic electrical concepts; network theorems; circuit laws; resistance, capacitance, inductance; response of RC, RL and RLC circuits to initial conditions and constant forcing functions; AC steady-state analysis and AC power; integration of computer applications using PSPICE.
  5. Jan 12, 2006 #4

    Tom Mattson

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    For this you only need to know algebra, calculus, and basic physics (electricity and magnetism).

    These are first-order circuits, and are thus described by first-order differential equations. RC and RL circuits with no forcing functions are described by homogeneous first order equations, and those with forcing functions are called inhomogeneous first order equations. You will need to know how to solve both.

    These are second-order circuits. You'll need to know how to solve second-order differential equations, both homogeneous (no forcing function) and inhomogeneous (forcing function).

    Somewhere along the way you will need to learn how to solve second-order equations with Laplace transforms. Now in my circuits book (I teach electric circuits at a small college) there is a chapter devoted to this and I actually teach it from scratch. That may or may not be the case with your course. If it is not the case, then ask the instructor at what point you will be expected to know Laplace transforms.

    You will have to be up on your complex algebra (both Cartesian and polar form), as you will be dealing with complex quantities called phasors.

    I don't expect that you'll need any new math for this part.
  6. Jan 12, 2006 #5
    hmmm.. looks quite though....

    I am also taking Calculus III (4 Credit), Linear Algebra (4 credit), C++ for Engineering (4 credit)...in this semester...along with electric circuit I....
    what do you think? .. Do i have enough time?

    And how deeply do I need to know those Diff eqn related problem? Just basic knowledge woyuld be fine or...Do i have to be able to do complex one too?

    Coz when I took Physics I they asked me to take Calc I first....as pre requisite...but..later when I took Physics I .....calculus..was used very lightly....that too was simple...calc..So I just wanted to know..how good Am i supposed to be in those Diff Eqn thing?

    Please dont hessitate to answer this...I am totally lost....But you could shed some light.
  7. Jan 12, 2006 #6

    Tom Mattson

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    That's a heavy load. Only you can be the judge of whether you have the time to do it.

    If your circuits course is like the one I teach, then you will only need to know how to solve 1st and 2nd order equations with constant coefficients. If this is true of your course then it will greatly simplify your life. You should ask the instructor if there will be differential equations with variable coefficients just in case.
  8. Jan 12, 2006 #7
    I know that the Engineering program at my University requires Engineers to take a fall semester of "Electronics I" which covers all of the topics in your Electric Circuit I except for PSPICE which is done during the first lab of the winter semester in "Electronics II". The Ordinary Differential Equations course at the University is only offered in the winter semester, due to its Math pre-requisites.

    There' s nothing like speaking to the relevant professor(s).
  9. Jan 12, 2006 #8
    I really cant talk to my prof aboout me taking Electric circiut I without Diff eqn....Coz he will throw me out of class and probably yell at me " How were yuo able to register for Electric Circuit I without Diff Eqn".....I think I should folow YOUr advise...you seen to know about it well......Dont know what i am supposed to do?
    You have any idea...how "C++ for engineers" are? Coz if this is not taht hard..i might dare for....taking Electric circuit I and spening some time on Diff eqn.....
    Btw I have already did basic C++...long ago...taht might help.. to make it easy...
    Any idea>?
  10. Jan 12, 2006 #9

    Tom Mattson

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    You don't have to tell him that you haven't taken diff eq. Just ask him if there will be differential equations with variable coefficients and if he will spend any time teaching Laplace transforms. They are perfectly reasonable questions to ask even if you have already taken diff eq.
  11. Jan 12, 2006 #10
    Exactly! I would highly recommend speaking the professor as each University/College teaches different material in similar courses and that could have different effects on different students.

    His feedback should ultimately be the deciding factor for you, when deciding whether to take or not to take the course. I am assuming that you have spoken to a guidance counsellor. Personally, I like to speak (and have spoken) to personnel (professors, counsellors, assistant chair if available) from the relevant department about such types of questions as THEY are the ones who have the best idea about the program that YOU are in and the courses that YOU will ultimately be taking.
  12. Jan 12, 2006 #11
    I just emailed the person who was going to register me for "Electric Circuit I"....letss see...
    But i dont think she will aloow me..coz...when I was talking about registering "Electric circuit I" she was asking me..."whether I have registered for Diff Enq or not" so many time.....but Probably I will know it by tomorrow.
  13. Jan 12, 2006 #12
    And btw she was the one who talked with my advisor about it
  14. Jan 12, 2006 #13
    well, you will be solving first and second order circuits using first principles, which will result in you needing to solving solme first and second order DEs (sometimes using Laplace transforms and sometimes using some other DE technique). Most of the time you will be transforming the entire circuit into the s-domain and then analyzing the circuit using resistive circuit analysis methods.

    However, DE solution techniques and Laplace transforms will be used extensively in circuits, along with convolution, unit step functions, and dirac delta functions, and these are all first introduced in DiffEQ. In circuits, you will likely get a brief review of these concepts, but it might help to have the DiffEQ class ahead of time. At my school, DE is a co-req of circuits 1.

    Bottom-line: it will likely help a lot if you take DE before taking circuits 1. I took DE before circuits 1 and it was beneficial.
  15. Jan 13, 2006 #14
    Agreed..I did the same.
  16. Jan 17, 2006 #15
    I kinda Have a solution for your problem here,
    search Google for "MIT open course ware" and go to the mathematics section, and then go to the ordinary differential equation course, you will find the lecture videos, notes, assignments and the reading for the course download it and watch it on the weekend, then take the circuits course and if you find your self needing some revision while taking the course just open the video you need and read the lecture notes and solve the assignment
    Hope this helps.
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