1. Robert123

    Thread Starter New Member

    Feb 12, 2010
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    I want to buy a device without to program a CPU that does the transform FFT for 20 – 500 Hz frequency.
    I know that is devices that do FFT for the frequencies of the AUDIO
    Where I can buy devices that do FFT for 20 – 500 Hz
     
  2. t06afre

    AAC Fanatic!

    May 11, 2009
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    My guess would be that perhaps a modern digital Oscilloscope could do this.
     
  3. Wendy

    Moderator

    Mar 24, 2008
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    So what the heck is FFT?
     
  4. Robert123

    Thread Starter New Member

    Feb 12, 2010
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    Thanks t06afre, but I don't search after Oscilloscope
    I search after electrical device that I can put in the electrical circuit
     
  5. t06afre

    AAC Fanatic!

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  6. beenthere

    Retired Moderator

    Apr 20, 2004
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    With all the computation required, a programed device like a DSP chip would be necessary.
     
  7. t06afre

    AAC Fanatic!

    May 11, 2009
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    FFT is an algorithm that give a numerical result as the output. It is not some physical device say like an OPAMP. So I think we need much more information about your project, else we will not be able to help.
     
  8. Papabravo

    Expert

    Feb 24, 2006
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    The Fast Fourier Transform is a digital algorithm. As such it requires a digital device to implement it. To create something remotely similar in the analog domain would require a collection of sharp bandpass filters, say ten of them. Feed the same signal to each one and the output of each filter will be the amount of energy in each passband.

    This will be way more trouble and expense than using a DSP chip. Much less flexible as well. I gaurantee you will be disappointed with the results of such a "crude" analog spectrum analyzer.

    What is wrong with using a DSP chip anyway?
     
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