RC shift oscillator using transistor bc547b

Discussion in 'The Projects Forum' started by leonel, Aug 31, 2010.

  1. leonel

    Thread Starter New Member

    Aug 31, 2010
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    hi im new in this forum and dont realy knw how it work i need help on build a shift oscillator with a bc547 i realy dont knw how to start. and the requierment are 2v(p-p) frequency 2000hz and using 9v dc
    plz help me
     
  2. Audioguru

    New Member

    Dec 20, 2007
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    896
    The oscillator is called a Transistor Phase-shift Oscillator.
    Google has 112,000 links to schematics and parts lists. The calculation is shown for the frequency.
    A few use the BC107 which was the same as a newer BC547.
     
  3. leonel

    Thread Starter New Member

    Aug 31, 2010
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    plz can u give me some glue how to start the calculation?bcz im doing the research about but im geting nothing much.
     
  4. Wendy

    Moderator

    Mar 24, 2008
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    Think 60° phase shift for each RC oscillator. The transistor input impedance should also match the other resistances.

    While not what you are asking for this comes close. Just use an inverting transistor instead of a op amp.

    http://en.wikipedia.org/wiki/Phase_shift_oscillator
     
    Last edited: Sep 1, 2010
  5. Audioguru

    New Member

    Dec 20, 2007
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    Here is a link to a transistor phase-shift oscillator. It has a simple single transistor amplifier and a phase-shift network with 3 RC phase shifts. the formula is provided to calculate the values for the phase shift R and C.
    http://www.electronics-tutorials.ws/oscillator/rc_oscillator.html
     
  6. leonel

    Thread Starter New Member

    Aug 31, 2010
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    thnks for ur help but my problem is i want a frequency of 2000hz and how m i gonna find the value of my Re Rc Rb in my amplifier?
     
  7. Audioguru

    New Member

    Dec 20, 2007
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    Re, Rc and Rb are the parts of an extremely simple single transistor amplifier.
    The value of Rc is determined by how much supply current will be used and by the load resistance.
    Re and the two base bias resistors are simple calculations.
    The two base bias resistors in parallel and in parallel with the calculated input impedance of the transistor amplifier should be equal to the R of the RC phase shift parts.

    If you cannot do these simple calculations then look in Google for a completed circuit.
     
  8. marshallf3

    Well-Known Member

    Jul 26, 2010
    2,358
    201
    Didn't your electronics course come with a required textbook?
     
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