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Bubba Oscillator in Proteus

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Mehboob Aam

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I am trying to generate 53 Hz signal with bubba oscillator and I am simulating in proteus. I have made the gain = 4, and the phase shift is -180 degrees, as required for oscillation by bubba oscillator.
in the circuit, RF = 10k, Rg= 2.5k, Vcc = +12Volt, VEE = -12Volt. R = 9.1k , C= 0.33uF.

when I run the simulation on proteus , there is no output.
as a friend of said, it needs some noice signals to run the oscilations in bubba and proteus simulation does not have it (noise) and suggested to make gain a little bit more than 4. I did as accordingly but still I don't have any output.
the proteus is giving me some errors, like one is ' Pin '+v' is not modeled. I think this could be the reason of no-oscillations.
Given bellow are the links for circuit diagram and the error messages screen-shot images.

How can I get rid of these error messages and get the output as expected?
shall be thankful for your worth full response.

https://obrazki.elektroda.pl/6738114800_1427228082.jpg
https://obrazki.elektroda.pl/1951832500_1427228083.jpg
 

Yes, you need to resolve the Pin not modeled error.
There must be an error in the op amp model.
Where did the op amp model come from?

To get the oscillator started you can put a voltage source in series somewhere in the feedback loop and have it generate a single short 1v pulse at the start of the simulation.
 

thanks for replying dear. I am using quad OP-AMP 3403. I picked it from library of proteus 8. I tried by giving a manual pulse at feed back, for a positive pulse and inverting input the output goes towards negative rail, after the pulse ends it comes back to its zero state(not output again), and the proteus errors " pin V+ and v- not modeled " still appears.

may be this is because proteus is unable to simulate the circuit. but i am sure this error can be resolved but don't know how to.
 

Make sure you are not using a model that can't be used for simulations. Try another similar op-amp. Sometimes a model may have problems or errors. I found that on several occasions.
 

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Make sure you are not using a model that can't be used for simulations. Try another similar op-amp. Sometimes a model may have problems or errors. I found that on several occasions.

is there any way in proteus to know if the device is modeled or not, or to update model. Texas instruments provide spice model, I don't know how to import it into proteus or update existing one
 

the op amp I am using is modeled , model name is " QA_BIP ".
 

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