Op Amp used as a function generator

Discussion in 'The Projects Forum' started by dj_wizard, May 11, 2009.

  1. dj_wizard

    dj_wizard Thread Starter New Member

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    Hey guys i need ur help i have this square and tri function gen.
    i did this circuit and it worked :D i only need to know the application of the resistance in it .. and also i changed the op amps to the lm741
    can anyone help plz ?
    thnx in advance

    here is the circuit [​IMG]
  2. Bill_Marsden

    Bill_Marsden Moderator Staff Member

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  3. dj_wizard

    dj_wizard Thread Starter New Member

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    but i didn t use the pulse generator 555 ... now i know the 2nd op amp works as an integrator to the 1st o/p which is a square function .. but how does the first one works ?
  4. bertus

    bertus Administrator Staff Member

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  5. dj_wizard

    dj_wizard Thread Starter New Member

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    thnx mate it was very helpful .. thnx both of u :)
  6. Audioguru

    Audioguru New Member

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    The performance of a lousy old 741 opamp is bad above only 9kHz. Many better opamps cost the same, are single, dual and quad and perform well up to 100kHz.
  7. thingmaker3

    thingmaker3 Retired Moderator

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    Perhaps you could prepare an update of National Semiconductor's Op Amp Circuits Collection (including the function generator of this topic, on page 9) using the modern chips. Then all the folk looking for circuits would no longer be offending you by using older style chips.
  8. Audioguru

    Audioguru New Member

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    The lousy old 741 opamp should have been buried 20 years ago.
    The very old LM107 opamp in the original circuit performs poorly above only 5kHz and was buried years ago.
  9. thingmaker3

    thingmaker3 Retired Moderator

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    So how about writing that upgrade? You could reduce the number of people learning on old chips! You could personally bury the old chips (metaphorically speaking).

    Or you could post a circuit here with a more modern chip.

    Or I suppose you could just keep whining. :rolleyes:
  10. bertus

    bertus Administrator Staff Member

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    Hello,

    Here is almost the same schematic from the datasheet of the TLC272, a cmos opamp.

    [​IMG]

    Greetings,
    Bertus

    Attached Files:

  11. dj_wizard

    dj_wizard Thread Starter New Member

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    it s only a small project i had to do :D... plus i don t need high frequencies
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