LED converted monitor

Discussion in 'General Electronics Chat' started by tom66, Jul 15, 2011.

  1. tom66

    Thread Starter Senior Member

    May 9, 2009
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    I don't let anything go to waste...

    Bought this 15" monitor for £10; fault description no backlight. Faulty inverter or CCFLs. Tossed both parts out, installed LED strip (cost £5, plus I had another 30 cm left...)

    http://www.youtube.com/watch?v=ETL8q5nq1ro

    Annoying how manufacturers charge so much more for LED backlights when they probably cost less overall...
     
  2. praondevou

    AAC Fanatic!

    Jul 9, 2011
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    Awesome!! U used the input voltage that was driving the inverter I guess? What are common voltages there?
     
  3. tom66

    Thread Starter Senior Member

    May 9, 2009
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    I plan to eventually run it straight off the 18V which is provided by a power brick capable of at least 2A. The LEDs draw a modest 250mA at 12V, provided by my bench power supply. I'll use a simple resistor to drop the volts down. If I was very bothered about efficiency, I would build one of my buck converter drivers, but I wanted it done quick. ;)

    I attach a pic of it working with VGA input; perfectly usable as a display. I was worried that it wouldn't be bright enough but it is. :)
     
    Last edited: Jul 15, 2011
  4. KJ6EAD

    Senior Member

    Apr 30, 2011
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    Nice. I've got to start looking for those easy fix deals. I imagine you'll want to revisit your color adjustments on the LCD after the LEDs have settled down from their burn-in period.
     
  5. tom66

    Thread Starter Senior Member

    May 9, 2009
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    If anything, LEDs keep constant brightness and colour, and CCFLs drift.

    I did a burn-in test for 6 hours; LEDs are barely warm even inside the monitor.

    I reset the monitor to factory settings, it looks even better.
     
  6. tom66

    Thread Starter Senior Member

    May 9, 2009
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    Okay! The conversion is complete!

    Assembly is all that remains... How many screws will be missing!? I tried to keep them in one place...

    The circuit for the MOSFET on/off is really simple, and is attached.

    I used an IRF510 because I had it on hand, if I were properly designing this I would order the right MOSFET. But the current is low enough that the MOSFET does not heat much.

    I used a MOSFET because I'm not entirely sure that switch would be happy passing 280mA as at present, it just controls a MOSFET on the main board.

    See the video on YouTube: http://www.youtube.com/watch?v=vevU_Fm6ap0
     
  7. KJ6EAD

    Senior Member

    Apr 30, 2011
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    I can't watch any more of your videos. I'll get motion sickness.
     
  8. tom66

    Thread Starter Senior Member

    May 9, 2009
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    Blame the lack of tripod and one handed point and shoot camera filming.
     
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