# NI circuits suite 11 (Multisim) problem

#### johnnydarten

Joined Feb 17, 2012
3
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.

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#### DerStrom8

Joined Feb 20, 2011
2,390
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.

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

Joined Feb 17, 2012
3
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

#### DerStrom8

Joined Feb 20, 2011
2,390
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
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 )

Regards

#### SgtWookie

Joined Jul 17, 2007
22,230
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.