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Use of solving complex DC circuits with Kirchhoff's laws

  1. May 20, 2011 #1

    in an introductory course on electricity, it is typical to use Kirchhoff's laws to write a system of equations for a complex circuit having several known emfs and resistors from which the unknown currents are then found. Is this something electrical engineers sometimes do in their work or is this a mere pedagogical exercice?

    Thank you.
  2. jcsd
  3. May 22, 2011 #2
    In the course, yes. For electrical engineers, on the job at least, circuit simulation software such as SPICE is used instead to speed up the process.The software essentially uses systems of linear equations with some modifications to find the currents, voltages, etc.
  4. May 22, 2011 #3


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    The point about Kirchhoff's laws is that they give you a systematic way to analyze any circuit, by setting up some equations and solving them. Therefore they are very useful for creating computer analysis software, etc.

    Often you can take "short cuts" when analyzing a circuit by hand and you don't want to find every voltage and current in the circuit, just a few things that you are interested in. But it is still valuable to know the formal methods, so you don't take incorrect short cuts that lead to the wrong answers!
  5. May 25, 2011 #4
    Thank you for your replies. Let me then rephrase my question.

    Could you give me an example of a situation in which an electrical engineer needs to find currents in a complex DC circuit?

    Thanks again.
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