Page 2 of 9 FirstFirst 123456 ... LastLast
Results 11 to 20 of 82

Thread: What exactly is the "correction amp" for??

  1. #11
    Join Date
    Jan 2006
    Location
    Akron, Ohio USA
    Posts
    1,754

    Default

    Yes! and make sure that you really are in 6 or 8 channel mode. If not, Windows Media Player might still play a 6 channel wave, but it will mix the channels together into stereo, left and right. Meaning, you get a terribly distorted image because it is the X and Y information with the color signals mixed in!

    James.

  2. #12
    Join Date
    Nov 2007
    Location
    Cairns, Australia
    Posts
    1,896

    Default

    hey, the only speed that actually works OK is like 13000, at quite a small size. These are the scanpro 20 galvo's, it should be able to go higher than that. It is in 6 channel mode. Are there any other EQ's I should know about, apart from the main sound card one, which is on default anyway, if i'm using Spaghetti? The distortion is there even without the op-amps, so they arent the problem.

    EDIT: Okay, here is one question I have had since I started. What does the - signal of the galvo's connect to? ATM, I have it connected as James did in his thread, to the other side of the little capacitor? And that ground, is also connected to the op-amp ground, which is onnected to the PSU ground. Is that right?



    cheers
    Last edited by Things; 09-18-2008 at 13:42. Reason: Oops, I wish my galvo'd coulr run at 130000pps :D

  3. #13
    Join Date
    Oct 2006
    Location
    Cleveland, Ohio
    Posts
    2,342

    Default

    Quote Originally Posted by Things View Post
    hey, the only speed that actually works OK is like 130000, at quite a small size.
    130,000 pps? no.

    if it gets better as you slow the speed, it's probably the galvo tuning. If it's always distorted to some extent, it's your sound card or settings. What sound card are you using

    edit: I see from your edit you are using the USB sound card, which is tested and works. You can ground the - side of the galvo, or just leave it unconnected.

  4. #14
    Join Date
    Nov 2007
    Location
    Cairns, Australia
    Posts
    1,896

    Default

    Erm sorry, I meant 13,000

    I am using the same sound card as James, the one that came in the little blue case.

    EDIT: This is how I have the whole thing wired...




    EDIT EDIT: I dont think my galvo's would be untuned, since they display the patterns on the DMX board perfectly fine. Is the short length of audio cable, between the sound card and op-amp, able to pick up much interference?

    It seems that everything is "Rounded" in a way, except for the circle, which comes out more squarish.

    Lemme try get a pic ...
    Last edited by Things; 09-18-2008 at 13:53.

  5. #15
    Join Date
    Jan 2006
    Location
    Akron, Ohio USA
    Posts
    1,754

    Default

    Ground the inverting inputs on your scanners. If you don't they will float and you'll get noise.

    If you are putting the sound card signal across the non-inverting and the inverting inputs of your scanners and you hooked nothing up to ground, that would explain why you would get a (relatively) centered image even though the signals would be all positive.

    That's not the way to do it!

    Ground the scanners input to the sound card ground. Put the signal into the non-inverting or the inverting input and ground the other one.

    James.

  6. #16
    Join Date
    Nov 2007
    Location
    Cairns, Australia
    Posts
    1,896

    Default

    The inverting inputs? What are they? THe - input, or do I have to ground them through the input thingy too?

  7. #17
    Join Date
    Nov 2007
    Location
    Cairns, Australia
    Posts
    1,896

    Default

    EDIT: Just reread your post. So, disconnect the sound card ground from the opamp circuit, and connect it directly to the galvos? What do you mean by the inverting wires? The + and - input on the scanners?

  8. #18
    Join Date
    Jan 2006
    Location
    Akron, Ohio USA
    Posts
    1,754

    Default

    Your scanners should have three wires as signal inputs. One of them is ground. The other two are differential to each other. That means that if you put the signal into one of them it will be right-side-up, so to speak. The other input will invert the signal and your scan will be up-side-down.

    The LaserBoy Correction Amp is NOT a differential signal source. It only has one end of the signal. So you can only drive one side of the scanner's inputs. The other, unused signal input on your scanners should be grounded.

    If you want to flip the image your scanners draw from top to bottom or from left to right, you need to switch which side of the input you are driving.

    James.

  9. #19
    Join Date
    Nov 2007
    Location
    Cairns, Australia
    Posts
    1,896

    Default

    Ahh OK, so would I ground both the ground of the scanner input, AND one of the - or + inputs?

  10. #20
    Join Date
    Nov 2007
    Location
    Cairns, Australia
    Posts
    1,896

    Default

    EDIT: Still no luck

    James, in the laserboy file, you know that green gear? (Frame 2) ?

    Well, the outside of that shows up VERY rounded, and the "prong" thingies that are supposed to be hanging off it, are just little lumps in the circle. THe inside bit is basically also round, the little bits sticking off the center circle are also very rounded, and arent re ctangle by far!

    Its almost like there is a capacitor there smoothing the output!!!

    Also, whenever I try using my webcam to get a pic, my craptop keeps saying ive exceeded my USB bandwidth >

    EDIT: I tried frame 4, and it starts to appear normal when its run at like 3000pps!! :O These galvo's are supposed to run at like 20,000pps, and this is running nowhere NEAR that..
    Last edited by Things; 09-18-2008 at 15:23.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •