Van der Pol oscillator circuit design in multisim

[Hammad-Farooq]

Hello experts 

hope you all are fine

i am facing a circuit design problem . i am working on van der pol oscillator. i want to simulate its circuit in multisim but not getting desire results. any will help to debug error or give other cirucit dsign for van der pol , i will appreciate it  ..

i attached circuit diagram  and  multisim file of that circuit which i am trying to simulate  

[Nrojas]

What is the problem you are seeing?

[Hammad-Farooq]

Thanks Mr. Nrojas . i have solved my problem .

actually some software simulation default setting was not working well . i changed that settings . and now it is working

[zlopezgallegos]

Hello! I was wondering how did you solve your simulation of the van der pol oscillator? I have tried different things but I do not have the desired outcomes.

Thank you!

[Hammad-Farooq]

What  problem actually  you are facing in simulation?

[zlopezgallegos]

Attached is my circuit diagram and I am sure I connect everything correct. Nonetheless, I do not have experience using this program that is why I think I am missing something but I do not know what it is.

[Hammad-Farooq]

in your given figure 

negative supply of U4 IC  is not grounded . every voltage should have some reference, in this case it should be ground . 

[zlopezgallegos]

Besides that everything seems right?

[Hammad-Farooq]

yes circuit diagram seems okay . if it is not still working . kindly share pictures of simulation results or any prompted error if occur .

[zlopezgallegos]

This is what I obtained. I do not know what I am doing wrong.