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Quick Thevenin Equiv Question

  1. Feb 19, 2007 #1
    What is the most general method that can be used to get the Thevenin equivalent for a circuit (one that always works)?
     
    Last edited: Feb 19, 2007
  2. jcsd
  3. Feb 19, 2007 #2

    ranger

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    Always works? I've yet to see a situation where the general methods dont apply.
    1)Remove the load.
    2)Find the open circuit voltage across terminals AB (Vth)
    3)Find the resistance looking in from the terminals (Rth) by shorting the voltage source or replace a current source with an open circuit.

    http://hyperphysics.phy-astr.gsu.edu/hbase/electric/thevenin.html
     
  4. Feb 19, 2007 #3
    What if you had dependent sources in that circuit? How would you find the resistance looking into the terminals? You can't short/open circuit dependent sources.
     
  5. Feb 19, 2007 #4
    3. Deactivate all independent sources. Insert a voltage source Vs between AB and measure the resultant current I; then RTh = Vs/I. Alternatively, insert a current source Is between AB and the resultant voltage V is measured; RTh = V/Is. You may choose any nonzero values for Vs and Is, e.g. Vs = 1V and Is = 1A.
     
  6. Feb 19, 2007 #5

    ranger

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  7. Feb 20, 2007 #6
    So is there a general method? What about test voltage/current source method? Does that method work for all types of circuits?
     
  8. Feb 20, 2007 #7
    Yes, the method is applicable on all type of circuits.
     
  9. Feb 20, 2007 #8
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