Ambilight type project?

Discussion in 'The Projects Forum' started by Trev21, Oct 18, 2006.

Thread Status:
Not open for further replies.
  1. Trev21

    Thread Starter New Member

    Oct 18, 2006
    8
    0
    Hey Guys, I'm looking for any help or information that could help me design an Ambilight type project to mount behind a LCD TV. I've been able to find some RED, GREEN and BLUE light strips to mount behind the TV, but am having trouble on how to drive them with the specific voltage for each bar based on the color that is currenlt showing on the TV. I figure that I will need to have some type of photo-sensor; one for each color. As for the technical stuff, I don't know where to start or what components will help me do this. I figured do the RED first and test it then do the same for the other colors and finally put them together. These light strips are 12" long and I figured that 3 or 4 strips of each color may do the trick. Any ideas how to do this? Thanks.
     
  2. Papabravo

    Expert

    Feb 24, 2006
    9,916
    1,724
    I've read your description three times and I can't figure out what you are trying to do or why you would want to do it. If a light strip is mounted behind the TV how can it be seen.

    Other than a CCD camera element I don't think the sensors that you want exist. I guess what you want is a sensor that measures luminous intensity in a very narrow band of wavelength(frequency). Photo diodes and phototransistors have a rather broadband response as do IR detectors with which I have a bit more experience.
     
  3. Trev21

    Thread Starter New Member

    Oct 18, 2006
    8
    0
    What I'm looking to do is similar to what you see with the phillips TVs. I figure that the color changes are driven at the digital level based on how the picture is painted on the screen. What I figured was that some type of sensor or standard photocell with, lets say a green filter over it. when the screen displays grass the filter should cancel it out, something would drive the green LED bars to light up behind the TV and flood the wall with green color. As the TV shows a blue sky the sensor with the blue filter would measure of sense the wavelength and drive the blue LED bars at which point the green LEDs would shut down flooding the wall behind the TV with blue color. This is the effect I'm trying for and this effect would be driven by color on the screen being displayed. I hope this gives you a better idea of it.
     
  4. Trev21

    Thread Starter New Member

    Oct 18, 2006
    8
    0
    These are the LED light strips I have in mind. They do have a power supply and a controller for them, but it only cycles the colors. I would like to have the screen colors drive the LED bars to match.

    http://superbrightleds.com/light_bars.htm
     
  5. Trev21

    Thread Starter New Member

    Oct 18, 2006
    8
    0
    "Photo diodes and phototransistors have a rather broadband response "

    This is where RED, BLUE and GREEN gel film can help narrow the response.
     
  6. Trev21

    Thread Starter New Member

    Oct 18, 2006
    8
    0
  7. Papabravo

    Expert

    Feb 24, 2006
    9,916
    1,724
    I would start by creating a schematic of the controller. That will tell you how to drive the light bars at least. As for sensing the color on the screen, you're on you own for that one. I'll be interested to know what kind of response you can get from a photdetector with a filter over it. I expect it will be pretty poor.
     
  8. Trev21

    Thread Starter New Member

    Oct 18, 2006
    8
    0
    I've seen some projects, but no schematics available so I'm seeing if anyone out there has any clue on designing it. Thanks for your help.
     
  9. Trev21

    Thread Starter New Member

    Oct 18, 2006
    8
    0
  10. Gadget

    Distinguished Member

    Jan 10, 2006
    613
    0
    Not sure how Philips do it, but it hasn't proven to be terribly popular here, and most new Philips flatscreens sold here don't do this any more.
     
  11. EEMajor

    Well-Known Member

    Aug 9, 2006
    67
    4
    That last link you posted (http://personal.pitnet.net/usr/gasperi/MUX2.HTM
    ) seems to be doing what you want, isn't it???? Maybe I am confused on what you are trying to do as well. It seems you could adapt their design fairy easily to drive some LED's.....

    Where are you going to mount the sensors so they get a good view of the scree, yet stay out of the way? If you mount it too close, you will get a poor sampling of the screen.

    Interesting project! Let us know what you end up doing to solve it!
     
  12. Papabravo

    Expert

    Feb 24, 2006
    9,916
    1,724
    I thought you said you had one(light strip) with a power supply and a controller. If you have the controller you can look at the PC board and create a schematic. In order to design something from scratch I would need some datasheets or other information on the light generating components.
     
  13. Trev21

    Thread Starter New Member

    Oct 18, 2006
    8
    0
  14. #12

    Expert

    Nov 30, 2010
    15,882
    6,402
    The Original Poster has not logged in for 9 years. I don't think he will benefit from your project.
     
  15. ScottWang

    Moderator

    Aug 23, 2012
    4,762
    756
Loading...
Thread Status:
Not open for further replies.