Looking for schematics

Discussion in 'Electronics Resources' started by sarahsman, Oct 25, 2013.

  1. sarahsman

    Thread Starter New Member

    Mar 18, 2013
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    I am working on a project dealing with DVD/CD players. Does anyone know where I can find some schematics of DVD/CD players so I can study some designs?
     
  2. Dr.killjoy

    Well-Known Member

    Apr 28, 2013
    1,190
    156
    Whats the problem ??
     
  3. DerStrom8

    Well-Known Member

    Feb 20, 2011
    2,428
    1,328
  4. sarahsman

    Thread Starter New Member

    Mar 18, 2013
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    No problems, just want to study them
     
  5. sarahsman

    Thread Starter New Member

    Mar 18, 2013
    3
    0
    I have searched google for a few days, nothing found there is complete. I was hoping to know if someone would know where I could find a library online of schematics of old electronics to get a better understanding of DVD/CD player designs
     
  6. WBahn

    Moderator

    Mar 31, 2012
    17,715
    4,788
    When I googled, "DVD player schematics" and just looked at the image results, there seemed to be a LOT of schematics there. I don't know what you consider "complete" for your purposes, but it sure seems that you are just wanting to get a better understanding of the designs, that there are a lot of things to help you along just from that one hit.
     
  7. kb50

    New Member

    Oct 27, 2013
    5
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    In older days, Pioneer was the one manufacturer that provided the most comprehensive repair and theory manuals. Right down to lissajous patterns at the cd eye level. Since there are hundreds if not thousands of designs it would be hard to pinpoint any particular design. Have you simply tried your local public library? I am sure they must have plenty of books on theory, repair, and design. Modern laser assemblies no longer have adjustments, they are self adjusting to the life of the player or recorder. In fact only very early desings include much information, nwer designs only have a schematic based on 1 or 2 LSI chips, and a handful of other components.
     
  8. kb50

    New Member

    Oct 27, 2013
    5
    1
    But why would you want to study old designs, vs new designs? Old desgins are no longer being manufactured.
    :):rolleyes:
     
  9. kb50

    New Member

    Oct 27, 2013
    5
    1
    In a basic cd player, the whole design hinges around 3 things. Data track, and 2 guard tracks on a per track basis. The actual data track comes out as a lissajou pattern, when viewed on a digital capable scope. The guard tracks are there to allow the eye pattern to align itself to the track, as the process is being generated. All this is the real time information being sent back to the LSI chip after being decoded. In the original design of a laser disc player was that used actual HeNe laser tube, and 2 mirrors held on voice coils that would pivot to self align to the lens. The lens was also mounted on a voice coil design to allow it to focus onto the reflective coating of the disk, and read the holes, or pits in the disc. Because the disc cannot be perfectly round the mirrors are there to jitter the beam allowing it to track the recorded information, passing thru a rerfractive prisim and onto led based photo sensors.
    Over the years it all simply become smaller and more integrated. With the advent of solid state lasers being the big breakthru in size and design. Way back 20 years ago, I actually had one of the very original Video Disc players, that used the 12 inch LD discs. 30-60 minuteds of Movie in Lower than SD quality. Sadly when I aqquired it, it would not even play, I was able to get it playing for a vrery short time, once, but it was just so badly worn out it would no longer track so well. It wasa Phiilips I believe or maybe Magnavox same as Phillips. The thing weighed like 50 pounds. I soon scrapped it out. But it did give me the opportunity to study how CD players worked.
     
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