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Homework Help: Simple Diode Circuit Analysis

  1. Sep 12, 2009 #1
    1. The problem statement, all variables and given/known data

    Attached is the homework problem I'm having difficulty with. I need to sketch vout for the circuit, assuming the diode ON voltage is 0.6 V. I'm stuck at how to begin this problem.

    2. Relevant equations

    3. The attempt at a solution
    It's only the 2nd week of class so I'm not too good with this, and I'm a bit rusty with my circuits as it is. My initial idea was to find the current going in the circuit but I'm just absolutely confused by this question. I don't understand why there are voltage sources after the diodes and what that does to the circuit. I also get confused with how I should find the current with an AC voltage source. Any guidance in the correct direction would be greatly appreciated.

    Attached Files:

    • hw1.doc
      File size:
      32.5 KB
  2. jcsd
  3. Sep 12, 2009 #2


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    The diodes will conduct when the voltage at their anodes is 0.6V above the voltage at their cathodes.
    While neither diode is conducting, there is no current, so, no voltage drop at the resistor.
  4. Sep 12, 2009 #3
    Okay, that makes sense. What do the DC voltage sources after the cathodes do to the circuit?
  5. Sep 13, 2009 #4


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    They assure that the diodes will fire only when the AC source voltage is 0.6V over or below the voltages of the DC sources.
  6. Sep 13, 2009 #5


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    Staff Emeritus
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    Homework Helper

    Depending on what Vin is, each diode can act like either a 0.6V voltage source or like an open circuit (i=0).

    For example, if the left-hand diode is at 0.6V, that would add to the battery there to give Vout=____?
  7. Sep 13, 2009 #6
    I actually figured out that the circuit was a clipping circuit. The sketch will oscillate between +5.6V and -8.6V. For some reason I wasn't able to recognize the circuit! Thanks for all the help!
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