Help in Wien Bridge Oscillator

Discussion in 'General Electronics Chat' started by ankur86modi, Jun 6, 2013.

  1. ankur86modi

    Thread Starter New Member

    May 10, 2013
    2
    0
    I'm trying to design a Wien Bridge Oscillator in PSPICE but i'm not getting the output without any input.

    i'hv tried numerous arrangements but can't get the desired result.

    plz see attached file for circuit and tell me the corrections.[​IMG]
     
  2. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    It seems that you didn't manage to upload your attachment. Please try again.
     
  3. studiot

    AAC Fanatic!

    Nov 9, 2007
    5,005
    513
    I can't see the upload either.

    However I would comment as follows.

    A wein oscillator is self starting and does not require an input. (the gain should be set to 3 and a bit for oscillation)

    It is possible that you have grounded a feedback loop depending upon your configuration. Are you using an op amp?

    Some configurations cannot be ground referenced.

    Some of this may help.
     
  4. ankur86modi

    Thread Starter New Member

    May 10, 2013
    2
    0
    Sorry, now i uploaded the image correctly.

    i'm getting the o/p but it is somewhat clipped from top n does not appear exactly sine-wave.

    i'm using uA741 op-amp with 9v dual supply.

    i'm totally choked what to do with the R & C values?

    plz guide me.

    Thanks
     
  5. Shagas

    Active Member

    May 13, 2013
    802
    74
    the bridge looks fine imo

    Try varying the 10k feedback resistor until you start getting an oscillation.
    Or try varying the feeback resistors to 4,7k and 10k and see if it makes a diffrence (doubt it but worth a try)
    Also try the 2 diode stabilisation method here
    http://www.learnabout-electronics.org/Oscillators/osc34.php
     
  6. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
    657
    The 741 is a poor op amp, especially for a 16kHz oscillator. Its slew rate is too low.
    Try a better op amp, like TL071.
     
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