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Princess 4.5 inch TV

Discussion in 'Electronic Repair' started by Andrew Tweddle, Jun 6, 2007.

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  1. Has anyone got a schematic or a method for adapting a Princess 4.5 inch
    TV to AV in. I need a small composite monitor for an old machine.

    Also where could I find a composite monochrome 6 - 10 inch flatscreen
    new or salvaged out of some consumer item to build into the said machine.

    regards Andrew
  2. Sounds to me like somebody didn't google first.

    If you do not google before posting your question I will have to send
    a complant to your ISP.
  3. Tim

    Tim Guest

    Just use an RF modulator. You can get them at Radio Shack or Walmart.

    - Tim -
  4. msg

    msg Guest

    Andrew Tweddle wrote:

    Last year I found some interesting web sites documenting the use of
    the Sony Watchman (tiny CRT-based TV with a flat screen and very slim
    profile) as the embedded monitor for some clever handheld projects.

    Search the web and if you can't find what you need, I'll search our
    local archives.


  5. Guest

    Just a case of feeding it in after the tuner, and getting a point
    where the signal is the right way up. I've done this with a bigger TV.
    Thankfully miniatures normally run off an ext transformer, so no psu
    isolation issues.

    So the challenge is finding the right point, where the signal becomes
    baseband. Output of tuner is where to start. I'd either scope the
    possible points first, or maybe use a piezo with series R to check
    they sound right, if theres any risk to a scope.

    C/R etc might be needed to tweak the input signal to suit the tv, due
    to dc offset. A cap on the input is good practice, as composite
    outputs can have dc on them.

    I'm not sure what else you need to know.

  6. Guest

    Reported as SPAM.

    Peter Wieck
    Wyncote, PA
  7. I eventually found a schematic of the KA7511 IC that runs the TV and it
    had a generic schematic, unfortunately it was unreadable. I then
    followed your advice and scoped the IC to find pin 5 was the output from
    the tuner which gave me a baseband video signal. I connected up an RCA
    socket to this point and I now have an external picture running over the
    normal picture. Next trick is to disconnect pin5 and insert the signal
    and a switch in the chain.

    Thaks for the help.
  8. Franc Zabkar

    Franc Zabkar Guest

    The KA7511 is an SMPS controller, ie a power supply IC. It has nothing
    to do with the tuner or IF stages.

    Here is a legible datasheet:

    - Franc Zabkar
  9. Guest

    Good news. I dont know which bit of the cct sets up the dc levels
    there, bit it might just be whatever you disconnect of course.

  10. Frank, my mistake, it should have written KA2915. Another project was on
    my mind.

  11. Franc Zabkar

    Franc Zabkar Guest

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