Audio source connection for LED spectrum analyzer

Discussion in 'The Projects Forum' started by dyeraaron, Feb 11, 2010.

  1. dyeraaron

    Thread Starter Active Member

    Oct 27, 2008
    57
    0
  2. dyeraaron

    Thread Starter Active Member

    Oct 27, 2008
    57
    0
    Someone please...do I hook an RCS jack up to a stereo ??? I don't know...please help
     
  3. dyeraaron

    Thread Starter Active Member

    Oct 27, 2008
    57
    0
    i FIXED MY ERROR
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Both are up to you. Assuming an audio source, a cable with RCA plugs is most common, but not necessary. Any coaxial cabling will shield noise, so BNC-BNC cabling (or SMA, UHF, any coaxial connector at all) will also do.

    What source are you interested in looking at? The block diagram had nothing about the input in the part I scrolled through. Can you fill us in?
     
  5. dyeraaron

    Thread Starter Active Member

    Oct 27, 2008
    57
    0
    I was thinking to use my Ipod that has an Aux. port type connection cable....and then I could wire in a speaker to actually hear the music but the spectrum dance to the beat???? Now I just have to find a female plug in for the circuitry side coming from the ipod
     
  6. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    That Vietnamese circuit does not use enough parts to make the LEDs bright so they are dim.
    The circuit is for one channel. Make two circuits for stereo or add two resistors at the input to mix stereo into mono.
     
  7. BMorse

    Senior Member

    Sep 26, 2009
    2,675
    234

    You seem to have a thing for Chinese and Vietnamese (most probably any asian) circuits/ products..... Do you have a much better/functional CANADIAN circuit the op could use??
     
  8. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    We speak English in my part of Canada. Some of that Vietnamese circuit is in written in Vietnamese and I don't know what it says.

    The circuit is multiplexed so that each LED is lit for only 1/10th the total time so it appears at only 1/10th brightness which is pretty dim.

    There are audio spectrum analyser projects on the web that are written in English and have good brightness.
     
  9. BMorse

    Senior Member

    Sep 26, 2009
    2,675
    234

    Electronic symbols and circuits are pretty universal in my part of the world, I don't need to speak Chinese or Vietnamese to understand a circuit..... apparently in Canada, you also need words with the pictures, so someone could explain how things work, eh?
     
  10. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    Can you understand all this Vietnamese in the project?
     
  11. BMorse

    Senior Member

    Sep 26, 2009
    2,675
    234

    following the ENGLISH explanations included with the circuits, I can understand where they connect and what their functions are.... Do you need help with it??

    osc.PNG

    reset.PNG

    4017.PNG

    col driver.PNG

    let me know what about this Vietnamese circuit your mind can't comprehend, no matter how you slice it, it is not the fact it is written in vietnamese, it is the fact that it is written BY a vietnamese, I don't think any person with such an outlook on life should even be in this forum, this forum is open to anyone, no matter what ethnicity, creed, color, or religion they have, they don't impose their views and beliefs on you, don't do it to others....... this is my opinion, case closed (yours, not the ops).... so don't taint this ops thread anymore than what it already has been....
    My Last .02
     
  12. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    I have seen and commented about this project on other website forums. It is on my hard drive.

    My opinion is that the entire project should have been written in English, not just part of it.
    I don't care what country the author comes from. The war was with America, not with Canada.

    The project uses a multplexed display and the row driver is a single low current LM3914 so the LEDs will be fairly dim.
     
  13. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    I'm just wishing that more people would use 741 opamps in their spectrum analizers so that AudioGuru could have more to complain about. :)
     
  14. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    741 opamps were fine 32 to 42 years ago. There are many better opamps since then.

    This spectrum analyser uses TL082 and TL084 opamps which are much better than a 741 opamp and are dual and quad. But I would use TL072 and TL074 opamps because they are low noise and might cost less.
     
  15. BMorse

    Senior Member

    Sep 26, 2009
    2,675
    234

    Do you think that is why he is using transistors as the column drivers to increase the LED's current, or maybe you didn't understand that part since it is in English and not french :cool:.....
     
  16. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    Transistors increase the current in the columns but not in the rows. So the low current in the rows from the single LM3914 is the determining factor in the brightness of the LEDs.

    The column drivers use transistors because they are driven by CD4069 low current Cmos inverters. The project does not mention the recommended power supply voltage but if it is 10V then the CD4069 inverter has a typical output current of only 12mA when it has a 5V loss. Maybe the author thought their current is less or maybe he used a supply voltage that is only 5V when the output current from a CD4069 inverter is typically only 3mA.

    The LM3914 row driver has a 1k resistor as the load on its voltage reference so it regulates the LED current to only 12mA.

    Since the LEDs are multiplexed 10:1 then the LEDs will look like they have an average current of only 1.2mA which would look pretty dim.

    If 10 LM3914 row drivers are used and their output current is increased to 25mA then the LEDs would not be multiplexed and will look as bright as my Sound Level Indicator project. It is a VU meter using one LM3915 driving 20 bright LEDs without multiplexing.

    Please do not insult me about French. Canada is "bilingual" because 13% speak only French. Many more than that speak only Chinese. The French speaking people are in Quebec which is far from my city. The French speaking people in Quebec wanted to form their own country and break Canada apart. Hardly anyone speaks French in my part of Canada.
    I last spoke French about 49 years ago in high school.
     
Loading...