Op Amp Sine Wave Oscillator

Discussion in 'The Projects Forum' started by nerdegutta, Aug 2, 2010.

  1. nerdegutta

    Thread Starter Moderator

    Dec 15, 2009
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    Hi,

    I'm trying to make this, see att schematic, sine wave oscillator.

    I found the schematics in this document:http://www.calvin.edu/~pribeiro/courses/engr332/Handouts/oscillators.pdf

    My question is this: What type of Op Amp would be best suited for the job?

    I have: LM358, LM386 and UA741CP.

    The frequency is not an issue, yet...

    Thanks for any help or links.
     
  2. tom66

    Senior Member

    May 9, 2009
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    The LM386 is not an op-amp it is a standard audio amplifier, so that cannot be used.

    It depends if you plan on using a dual polarity supply.

    The LM741 cannot go to the V- or V+ terminal, so it is out if you want to use a grounded V- pin.

    However the LM358 can go to ground so it is more ideal. I recommend the LM358.
     
  3. t06afre

    AAC Fanatic!

    May 11, 2009
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    Can you tell more about what frequency you plan to use. Also do want to use double or single power supply. I can find a good one in the ELFA assortment. And eh...it will NOT be a 741 variant:eek:
     
  4. nerdegutta

    Thread Starter Moderator

    Dec 15, 2009
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    I was actually planning on using a 9v battery. Is that a problem? I've also an old PC powersupply lying around.

    Thanks for quick replies.
     
  5. Wendy

    Moderator

    Mar 24, 2008
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    Something like the old LM324 quad would be good for a bubba oscillator.

    You will need a ½Vcc reference, which is easy enough to do. A simple op amp follower after a voltage divider would work nicely.

    The old 741 is a good teaching tool, but for a practical project I would use something a little newer.

    High Speed Op Amp Query
     
  6. Audioguru

    New Member

    Dec 20, 2007
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    The LM324 quad and LM358 dual opamps have crossover distortion which is bad for a sine-wave oscillator.
     
  7. t06afre

    AAC Fanatic!

    May 11, 2009
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    Jensemann! can you tell us more about what you are planing to build. It would help to know what kind of application you will connect to the generator output
     
  8. nerdegutta

    Thread Starter Moderator

    Dec 15, 2009
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    Hi.

    In the end, I will try to measure inductance with a multimeter.

    The article I've read, explains that if I connect a resistor and an inductor in paralell, set a sinus wave on it, I will be able to read the inductance of the inductor.

    I have seen some circuits, and I thought that I might be able to build this one.

    Am I wrong?

    PS. Guys at work call me Jensemann, vesle Jensemann or just Vesle. :)


    Edit: Should be connected in series, not paralell.
     
    Last edited: Aug 3, 2010
  9. nerdegutta

    Thread Starter Moderator

    Dec 15, 2009
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    Something like this
     
  10. t06afre

    AAC Fanatic!

    May 11, 2009
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    How about using your sound card as the sine wave source. I am just playing with ideas ;)
     
    nerdegutta likes this.
  11. nerdegutta

    Thread Starter Moderator

    Dec 15, 2009
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    OK... I'm listening. How can I do that?
     
  12. t06afre

    AAC Fanatic!

    May 11, 2009
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    You will find many free apps on the net. If I remember correct you are a linux person. try Google and Function Generator linux or waveform generator linux
     
  13. nerdegutta

    Thread Starter Moderator

    Dec 15, 2009
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    Thanks. I will do that. (As soon I get out of the prison people call day job.)
     
  14. nerdegutta

    Thread Starter Moderator

    Dec 15, 2009
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    A little update:

    You can get Linux to play a sound using something called SOX.

    I had to sudo apt-get install sox

    After that I can just type:

    play -t null /dev/null sine.wav synth 10.0 sine 1000.0

    It then plays a 1000KHz sine tone for 10 seconds. Instead of sine, we can put square, triangle, sawtooth, trapetz (trapezoidal), exp (exponential), whitenoise, pinknoise, and brownnoise.

    I'm quite amazed. :)

    This was really off topic... Sorry!
     
  15. t06afre

    AAC Fanatic!

    May 11, 2009
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    You will also find many apps with a GUI. But I guess you Linux people are allergic to such nonsense:p. Anyway this is your thread you can take it in the direction you want. I also think I could whip a an application using sound card I/O to do the measurement without any active components. in about 15 minutes, compleate with GUI. But that would be a Windows application made by Labview
     
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