function generator using CA3130

Discussion in 'The Projects Forum' started by endaya_walatch, Sep 26, 2009.

  1. endaya_walatch

    Thread Starter Member

    Sep 13, 2009
    33
    0
    what is the purpose of the arrowed part?? coz i have a difficult time in understanding it...

    thanks.,.
     
  2. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    If you are referring to the blue arrow, it is simply pointing to the input of the circuit.

    hgmjr
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    As hgmjr wrote, the blue arrow points to the input of the circuit.

    But to explain more fully, the input is measured in respect with the circuit's ground, or 0v reference. The round ball that is connected via a line to the three horizontal slashes is the ground.

    If you need more explanation, please reply stating as to what you are in doubt about.
     
  4. endaya_walatch

    Thread Starter Member

    Sep 13, 2009
    33
    0
    since i'm trying to simulate it, there is an error on that part.. can you give me a more useful software in simulating circuits.. by the way i'm using Multisim..

    thanks..
     
  5. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    Does Multi-Sim have a model for the transconductance amplifier the old CA3080A?
    The old CA3080A is obsolete and has not been made for many years. I don't think you can buy one anywhere.
     
  6. endaya_walatch

    Thread Starter Member

    Sep 13, 2009
    33
    0
    is that so??? so even i can make it worked, i will have a hard time to find that op-amp...
    by the way, do you a function generator schematic??or can you help me to make better improvement in my schematic??
    i want to know how can i adjust the frequency and the amplitude of the signals generated...

    thanks..
     
  7. endaya_walatch

    Thread Starter Member

    Sep 13, 2009
    33
    0
    hi.. can you help me to vary the frequency in this schematic?? i need to have a range of frequency of 6Hz-7 kHz.. urgent reply..please... thanks..
     
  8. Wendy

    Moderator

    Mar 24, 2008
    20,766
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    I don't think you can do it with one pot, you're going to need to be able to switch the capacitor out.

    Instead of starting a new post every time on the same circuit, why not continue the other one? I answered this question once, maybe twice.
     
  9. Dave

    Retired Moderator

    Nov 17, 2003
    6,960
    145
    Threads merged. Please don't create multiple threads asking the same question. Thanks.

    Dave
     
  10. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    R1 and C1 adjust the frequency. The following op amp integrators shape the waveforms. As the frequency goes up the amplitude will go down, as integrators are basically low pass filters. By the time you hit the high end the signal will be very small indeed.

    We went through this in this thread...

    http://forum.allaboutcircuits.com/showthread.php?t=27706

    I count 4 thread (after the merge), all asking more or less the same thing.

    Are you having trouble making the ones I showed you work? I gotta tell you, the schematic you're focused on is pretty bad.
     
    Last edited: Oct 2, 2009
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