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Homework Help: Finding current of the diode

  1. Nov 26, 2015 #1
    1. So I have a voltage input of 12V, resistor 1 of 2k ohms, and resistor 2 of 4k ohms. These are connected to a diode and a load resistance of 1k ohm and load. I am instructed to use second approximation

    2. The problem wants me to find load voltage, load current, load power, diode voltage, diode power, and diode current. I haven't had an issue with any except diode current.

    3. I started by finding the thevenin voltage of 8V and thevanin resistance of 1.3k ohms
    I found load current by subtracting VTH and 0.7 and dividing by the sum of RTH and RL. (~3.17 mA)
    I found load voltage by multiplying IL and RL (~3.17 V)
    Load power by IL * VL (~10 mW)
    Diode voltage is 0.7V because of second approx.
    Now, how do I find the diode current? My book seems to assume diode current is the same as load current. Why is that?
  2. jcsd
  3. Nov 26, 2015 #2


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    Staff: Mentor

    Hi tgitgi, Welcome to Physics Forums.

    Your problem statement is not clear for everyone. Note that we don't all have the benefit of being in the same class with you or having the same course materials to reference. So, Can you please:

    1. Provide a better description of the circuit or (even better) post a circuit diagram?
    2. Define what "second approximation" means.

    (Note that if the diode and load resistor are series-connected then they must share the same current)
    Last edited: Nov 26, 2015
  4. Nov 28, 2015 #3
    Your note answered my question. Thanks
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