Keeping your monitor out of blue / lost signal screen

Discussion in 'General Electronics Chat' started by dr_serious, Dec 16, 2011.

  1. dr_serious

    Thread Starter New Member

    Dec 16, 2011
    I have a old laptop 15.4" LCD screen that i converted to a monitor with a LCD controller. I'm planning to use this screen as a screen to view a signal that i recive from a wirless transmitter. But when my signal is to far from the source i loose the image and my screen goes in signal lost or blue screen until i recive a new signal. But every time I get the signal back theres a second delay until i get the image back becouse the monitor is slow i guess.

    Now im looking for a solution to trick the signal that the monitor gets with another noise signal. So when i lose the signal the monitor wil get the noise and dont lose go in no signal mode...

    Can you guys point me in the right direction with a circuit or something?

    The signal i receive is a video stream of a live camera NTSC: 510(H)*492(V) or PAL: 500(H)*582(V). (I would rather have it working with PAL then NTSC)

    I have a basic understanding of electronics/ circuits but I have totally no knowledge about video data.

  2. crutschow


    Mar 14, 2008
    It likely goes to a blue screen when it loses the sync signal. Do you have a schematic of the LCD controller board? If so you might be able to determine how to disable the loss of sync circuit and prevent the blue screen.
  3. SgtWookie


    Jul 17, 2007
    Another approach might be to use a missing pulse detector for the sync input; if it disappears, then send a phony sync signal until the sync reappears.
  4. dr_serious

    Thread Starter New Member

    Dec 16, 2011
    I can ask for the circuit but i cant promise they will give it, I know it is a programmable chip on the board. (I'll look up witch one) Coding the bluescreen out is one idea

    The camera signal is a BNC/RCA cable to a BNC to VGA converter.
    What would be the easiest to put the pulse detector on the BNC side or the VGA side? I would think the VGA digital side, its easier to work with a digital signal and you can use a 555 signal detector... But then is the question how to know witch data to send for the sync signal? A second camera but then its maybe easier to put it on the analog side? :)