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PSPICE question

  1. Oct 20, 2008 #1
    Hi everyone...

    I am trying to model and simulate an astable multivibrator using Pspice but i am having some difficulty....

    Both transistors are coming on at the same time so I never get the oscillations I expect. What do I need to do to make the model act more like a "real life" astable mulivibrator where one transistor comes on before the other one?

    (I have read it is possible for both transistors to come on at the same time in real life as well if the voltage is turned up slowly enough, but this is obviously not what I want if I'm trying to make a multivibrator.)

    Is there some PSPICE trick I am missing?

  2. jcsd
  3. Oct 20, 2008 #2
    I think I got it...I changed the intial voltage on one of the caps to be 0.1V and the circuit seems to work...

    Now I just have to reduce the charge up time so I get a nice square wave...
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