flat screen ccfl project help plz!

Discussion in 'The Projects Forum' started by Fritz HID, Apr 13, 2015.

  1. Fritz HID

    Thread Starter New Member

    Apr 13, 2015
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    I've been thru 2 diff flat screen tv's and I'm wanting to use the ccfl arrays for other projects but I'm hitting a serve roadblock.
    Both req 24v and I have that covered.
    There's a yellow (on) lead and a blue (pwm) lead.
    Does anyone know an easy way to false the pwm signal?
    OR does anyone know where I can find suitable power supplies/inverters to power 14 ccfl in 2s by 7 pairs at length of aprox 23" and about 3mm dia, each??
    I'd like to use these as light boxes (and yes I've thought about LED, no I don't want to go that way, I want to utilize leftovers)
    Any advice is welcome, Ty.
     
  2. Søren

    Senior Member

    Sep 2, 2006
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    The TV's that you got them from would have what's needed.
     
  3. Fritz HID

    Thread Starter New Member

    Apr 13, 2015
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    Yeeeeahhhh. Thought of that but not an option. Don't ya think I'd have salvaged that if I could have?
     
  4. Søren

    Senior Member

    Sep 2, 2006
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    28
    I don't know, some people pull a harddisk to pieces, save the motors and toss the board containing drivers for both motor and heads and then ask in places like this how to drive them, some are smarter and save it all.

    Do you know what the voltage on the yellow wire should be (or is it just the positive supply lead that you refer to as "on")?
    Do you have any idea of the approximate frequence and amplitude of the PWM?
    Do you still have the inverter to drive the CCFLs?
    If the above is known (more or less), a PWM signal is easy to make.
     
  5. Fritz HID

    Thread Starter New Member

    Apr 13, 2015
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    Yes, I have the inverter itself. The stock power supply.
    The yellow is a +5v signal.
    The pwm is the area I'm having issues with. on one light, I can get it to fire but very dim w/o pwm, and thus far every signal I've sent has made it strobe, but doesn't very when I change pwm (200hz 10-100%duty)
    I do not know the stock freqs, was hoping someone on here may have exp w/these.
    If not, just a new set of inverters (I cannot find adequate for these tube sizes on line) will work just fine. Doesn't have to be fancy, just want them lit to their full potential.
     
  6. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
    2,804
    1,237
    @Fritz HID

    Are you certain that's a PWM input? --- CCFL intensity control is generally implemented on the analog 'leg' of the regulator feedback loop...

    Best regards
    HP
     
    Last edited: Apr 15, 2015
  7. Fritz HID

    Thread Starter New Member

    Apr 13, 2015
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    Well, I'm not 100% but it does say pwm on the board for that lead.
     
  8. Søren

    Senior Member

    Sep 2, 2006
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    28
    I've yet to dismantle a flat screen TV, so if you've already tried PWM, I'd just be guessing.
    You can get inverters for CCFL in several configurations and sizes at http://www.lcdparts.net/U3D.aspx if all else fails.
     
  9. Fritz HID

    Thread Starter New Member

    Apr 13, 2015
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    Oooo so close! Ty tho, I may have to make shift something with a few inverters from there.
    Difficult part is, the tubes are 24" on the small one, there are 14 tubes, and they are wired in 2s for a set of 7.
    There no inverters, I've found, for 7 +48" tubes.
    I've looked for an opticoupler that I could just bypass (like on xenon/merc arc power supplies on projector tvs) but no luck.
     
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