Circuit Analysis Help

Discussion in 'General Electronics Chat' started by nshepar2, Oct 13, 2011.

  1. nshepar2

    Thread Starter New Member

    Oct 13, 2011
    12
    0
    Hello all. I have gone back to school to finally get a degree after 20 years, and I thought I would try EE. But I am having a Major Problem! No matter how many times I sit with a tutor or read the textbook I can not get circuit analysis. I have dropped my first class to credit only and already plan to fail it and retake it next semester.

    My question to this group is, can anybody offer help? I understand power, as in generation and such, just not electronics. What I really want is to be a power engineer in the renewables, not build cellphones, computers and the like.

    I will take any help, get any book, whatever that may help because I need to get this degree and get a job.

    Thanks
    Neil
     
  2. #12

    Expert

    Nov 30, 2010
    16,248
    6,745
    Start reading the books listed at the top of this page. Circuit analysis is about knowing what each part does. This is a good place to start.
     
  3. steveb

    Senior Member

    Jul 3, 2008
    2,433
    469
    Give us a clue as to what the stumbling block is. If you don't know, ask your tutors to help you figure it out. It could be some weaknesses in your background, like math which is critical for analysis. Or, it may be a difficulty in abstraction because voltages and currents are not easy to visualize. Or, maybe you don't like the subject and it's hard to focus on it. Or, maybe it's something else.

    You have this forum to ask any particular questions, and the ebooks available, as #12 mentioned, are good for general learning. If you have enough spare time, doing some hands on building of circuits, while learning the theory of operation can help. This forum can help on that front too.
     
  4. nshepar2

    Thread Starter New Member

    Oct 13, 2011
    12
    0
    Basically it's like being color blind to red and all the circuits drawn out for us in homework and tests are drawn in, you guessed it, red. I look at them and know I should use KVL here or KCL there, but then I don't know what happens. Understand I do know what KVL, KCL, Ohm's, etc are and I understand them. But when there is a DC circuit where they want to know I3 and don't give any other currents, My professor and tutors have done things like I1-I2 for one branch and created supernodes on the third branch of a three connection node which flows off into places my brain just does not see. I can read a blue print, build anything in wood and steel to spec and have no issue, but hand me a 1st year dc circuit to analyze, forget it!

    The attached image of a simple circuit is from a test. I got the KVL equations right. But the next problem on the test wanted me to find the current through one of the three. I settled on the 10Ω on the right. Set a ground and said at the top of the 6V node it's 6V....wrong. Not rushing to finish or anything. I actually almost erased through the test paper working on it. It's stuff like this.

    Maybe it's the textbook we use, written by the university department, and even the head of the department has said the book is not that great, but whatever it is I need help.

    Thanks
    Neil
     
  5. steveb

    Senior Member

    Jul 3, 2008
    2,433
    469
    It sounds like an issue of being able to visualize the topology and make abstract connections from equations to physical understanding. This is a tricky thing if you haven't done a some type of hands on circuit work. There is nothing like probing around a real circuit with a voltmeter or oscilloscope to help you visualize a principle like KVL. Lacking this experience, making an analogy with another physical system can help, such as water pipes, or mass/spring/damper mechanical systems or anything else that helps you make the connection. In the end you will be able to make these connections directly at the circuit level, but only after you have solved many many problems. I think that's the only way to get rid of the color blindness. Unlike real color blindness, this type of blindness will go away the longer you stare at the color that gives you trouble. This means banging your head against the wall, then coming here with questions, and then going back repeating this process many times. The fact that you have mechanical ability means that the talent is inside you somewhere, and you can coax it out if you keep working hard. You just have to train your mind to make the right connections between electrical symbols, circuit equations and physical understanding.
     
  6. nshepar2

    Thread Starter New Member

    Oct 13, 2011
    12
    0
    Thanks. Just needed to see if it can improve or if I'm wasting time and money.
     
  7. tgotwalt1158

    Member

    Feb 28, 2011
    111
    18
    Its never too late, since acquiring of knowledge is recommended from cradle to grave. Having said that, each person has unique born abilities which could be developed to excellent levels by learning and practicing. However, brain topologies for certain individuals are suitable for certain fields, e.g. if one can not excel in maths, may do wonders in music etc etc. First twelve years of life are considered best for learning since brain is quite raw, developing and at its functional peak during that period, so the efficiency of observation, memory, comprehension is at its best. This gradually declines with the age, so whatever was breeze to learn in early age, gets comparatively harder in the following years of life, and hence more effort and dedication would be required to achieve same goals.
    Coming to your particular case, you have to learn and master each circuit element whether active or passive, its function both in AC and DC circuits, then the general building blocks of electronics whether analogue or digital, then the existing designing topologies available. If you master these things in that order and develop the ability to retrieve that knowledge quickly then there is no doubt you will get what you are after for. One last word of advice, if there are two options available to solve one problem, go for the basic one since it will define the problem very well e.g. first try Ohm's law then voltage and current distribution laws, finally moving to more advanced e.g. KVL, KCL, Thevinin, Superposition, Norton, Maximum Power Transfer, Bode Plots etc etc. I always do like that and never failed.
     
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