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Thread: LFI Player + DAC problem

  1. #1
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    Default LFI Player + DAC problem

    Hello all... it's my first post but I'm here 4 months reading threads...

    I have homemade opamp correction board, homemade analog drivers and Cmedia CM106 sound card.

    I used max.wav file to calibrate output and laser is off when playing max.wav and laser is on when sound file is paused.
    I can change brightness linearly by moving volume slide, but when I use LFI player I cannot make it work.
    No matter what I do I cannot turn of any laser. There are almost unnoticeable changes in laser brightness.

    When I connect galvos and red laser here are results:



    Why it works with max.wav file and doesn't work with LFI player?

    Btw.... When I connect headphones (at channel where red laser is connected) I can hear sound. I can linearly change sound intensity in LFI player (by moving intensity slider) but cannot notice changes in laser brightness...

    Any idea how to solve this problem?

  2. #2
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
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    Do you have a oscilloscope?

    What are your current software settings?

    Steve
    Qui habet Christos, habet Vitam!
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    When I still could have...

  3. #3
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    Check the driver ini file. Try inverting the RGB outputs. Sounds like you are driving them with negative signals.

  4. #4
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    EzAudDac.ini is set up to invert the modulation output to match the default correction amp, but because you built your own, you will want to check this out. The invert setting can be yes or no

  5. #5
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    Quote Originally Posted by mixedgas View Post
    Do you have a oscilloscope?

    What are your current software settings?

    Steve
    No, I don't have oscilloscope, software is on default settings.

    Quote Originally Posted by JohnYayas View Post
    Check the driver ini file. Try inverting the RGB outputs. Sounds like you are driving them with negative signals.
    I tried, but nothing changed.

    Quote Originally Posted by drlava View Post
    EzAudDac.ini is set up to invert the modulation output to match the default correction amp, but because you built your own, you will want to check this out. The invert setting can be yes or no
    Nothing changed...


    Here is another ILD file...


    Same problems...

  6. #6
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    Quote Originally Posted by ReNNo View Post
    I used max.wav file to calibrate output and laser is off when playing max.wav and laser is on when sound file is paused.


    Why it works with max.wav file and doesn't work with LFI player?
    Those statements do not jive. If the laser is off when playing the wav file and on when paused then you do not have it calibrated correctly. You have it backwards. Please clarify what you have done and what you are seeing and I'm sure we can probably help. But, right now, what you are saying doesn't even make sense.

  7. #7
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    No matter how I adjust pots I cannot achieve 5V when playing max.wav and 0V when file is paused.

    Here is schematics I did ...
    http://www.speedyshare.com/files/24599232/Zavrsen.rar (EAGLE)

    I used this schematic:
    http://laserpointerforums.com/attach...ser-driver.jpg

    But I added another opamp.
    Creator of this schematics told me that this is OK and that additional opamp should solve problems if I use software that doesn't have "invert blanking" function.

  8. #8
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    Quote Originally Posted by ReNNo View Post
    No matter how I adjust pots I cannot achieve 5V when playing max.wav and 0V when file is paused.
    The entire purpose of the correction amp is to obtain is to obtain a centered +-5V range. I don't know what is wrong with your circuit but until you have that sorted out none of the software is going to work.

  9. #9
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    As you can see, galvos work just fine.
    Only lasers are problem.

    Opamps work, something is wrong with analog driver I think.

  10. #10
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    Galvos work within the entire +-5V range. Lasers only work within the 0+5V range. The output from these color channels on the sound card DAC is still +-5V but the software only sends values that keep it in the positive range. If the output is inverted, the software will essentially be driving the lasers only with negative signals. I don't know if this is your problem or not. But, since all of the channels are identical electronically, you should be able to easily compare and test. As a quick test, route your XY channels to your RG channels and display a test pattern. You should have laser output. If not, you have other issues that you need to resolve.

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