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Homework Help: Diode resistor circuit

  1. Aug 14, 2009 #1
    1. The problem statement, all variables and given/known data

    Find Voltage/Current across each diode:

    |......... |

    Repeat 50x until:


    V = power source
    D = diode
    R = wire resistance
    . = empty space

    2. Relevant equations

    for diode:
    V = 0.04654 * ln(I/(0.62E-19)) + I*6.97

    for wire:
    R = pl/A = 0.02 ohms

    Final diode voltage = 2V
    Final diode current = 20mA

    3. The attempt at a solution
    Attempted to use v = ir with wire resistance to find voltage over last-1 diode, but did not work out as current got higher as worked back to source.
  2. jcsd
  3. Aug 17, 2009 #2


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    Staff Emeritus
    Science Advisor
    Homework Helper

    Welcome to PF :smile:

    It took me a while to figure out how the circuit looks from your description.

    It sounds like you are on track to solving this. The diode currents (and voltages) should get higher as you get closer to the source.
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