1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Source Transformations

  1. Nov 12, 2015 #1
    1. The problem statement, all variables and given/known data
    Find the thevenin equivalent circuit by performing source transformations only.

    2. Relevant equations

    3. The attempt at a solution
    Answers: Vth=60v and Rth=30.
    I managed to get Rth correct, but I'm not sure if everything I did was "legal". I can't seem to find Vth.

    Attached Files:

  2. jcsd
  3. Nov 12, 2015 #2


    User Avatar
    Homework Helper
    Gold Member

    In the 3rd circuit, your transformation of V into I is wrong since the resistor and current source(transformed) are not in parallel. But you don't need a 3rd step. I think in the 2nd circuit itself, the answer is obvious (60V).
  4. Nov 12, 2015 #3


    User Avatar

    Staff: Mentor

    Your third step is incorrect. When a voltage source is transformed into a current source the associated resistor must end up in parallel with the current source. Also, you should work from one end of the circuit to the other, towards the output, in stages.

    Your first step, converting the 4 A source to a 40 V source allowed you to "swallow up" one 10 Ω resistor. The logical next step would be to convert this "new" voltage source and resistance back to a current source allowing you to "swallow up" more of the circuit with simple parallel or series combinations. Don't be afraid to convert back and forth between source types if it allows you to make progress in reducing the circuit.
  5. Nov 12, 2015 #4
    Thanks, I'll try reworking it!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted