NI circuits suite 11 (Multisim) problem

Discussion in 'General Electronics Chat' started by johnnydarten, Feb 17, 2012.

  1. johnnydarten

    Thread Starter New Member

    Feb 17, 2012
    3
    0
    Dear all,

    I have a small problem with multisim 11 which is being unable to find normal diode in the library. Can someone help with it? I attached some pictures which show that the diode I found starts conducting after 2v. forward voltage is applied to it. Normal diode conducts at 0.5v to 0.7v. I couldn't find that.

    Thanks in advance
     
  2. DerStrom8

    Well-Known Member

    Feb 20, 2011
    2,428
    1,328
    Hi Johnny. Welcome to AAC! :)

    I'd suggest finding a common diode in the list, such as one of the 1n400x series. Those are standard diodes that conduct at .7 volts. See if it makes any difference in your circuit.

    Regards,
    Der Strom
     
    johnnydarten likes this.
  3. johnnydarten

    Thread Starter New Member

    Feb 17, 2012
    3
    0
    Hi Der,

    Thanks for your useful reply. but What about ideal diode which is a short circuit when Vd>0 and open circuit when Vd<0? Is that found in Multisim 11?

    Johnny
     
  4. DerStrom8

    Well-Known Member

    Feb 20, 2011
    2,428
    1,328
    That is a good question. To be honest, I don't know. I have not come across one, but that doesn't mean anything. Perhaps there's someone else here with more experience than I do? (If there is, please speak up :D)

    I hope you find your answer Johnny. Good luck :)

    Regards
     
  5. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Instead of using a voltage source across the diode, try using a current source, and perform a decade sweep from say, 1mA to 1A.

    You're showing very large amounts of current in your simulation, so it's difficult to tell just when the diode begins conducting. Measuring the voltage across the diode with a small range of current will work much better.
     
    johnnydarten and DerStrom8 like this.
  6. johnnydarten

    Thread Starter New Member

    Feb 17, 2012
    3
    0
    Thanks Der for your help.
    For SgtWookie, in case of current sweep from 1mA to 1A the voltage across the diode surprisingly doesn't exceed 1 nV...however I didn't understand the idea of making a diode current not voltage derived. I'm just searching for ideal diode. Can you clarify?
     
Loading...