Page 7 of 17 FirstFirst ... 34567891011 ... LastLast
Results 61 to 70 of 165

Thread: 445 experiments

  1. #61
    Join Date
    Dec 2006
    Location
    denver,co
    Posts
    1,078

    Default

    That is intteresting I am just trying to figure out how the projector works.

    Is there a missing pluse time? I would think that the diodes are on for 2/3 of the video frame. On-green,on-blue,off-red using the motor timing as sync. What is the pulse frequency.

    Chad


    When the going gets weird, the weird turn pro.


  2. #62
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,248

    Default

    Red is not part of the wheel though, so wouldn't necessarily follow the same pattern, or indeed have to fit into a cycle 'slot' (so to speak)

    The wheel has the phospor (or whatever it is) around about 270 degrees of the rim with a window for the remainder. The reason why its such a high percentage is because the green needs a longer duration to balance the blue, I believe due to losses.

    Thats why I was interested in seeing the duty cycle if projecting just solid green, or just solid 445 shade of blue. I would expect to see the duty cycle change as the requirements of the colours change but thats just my theory.

  3. #63
    Join Date
    Nov 2009
    Location
    Maryland
    Posts
    320

    Default

    Rob - I wasn't trying to say you were wrong... I was looking for a thought about why that might be. I phrased it inartfully so sorry for that but I didn't mean anything by it...

  4. #64
    Join Date
    Oct 2009
    Location
    Eindhoven, The Netherlands
    Posts
    921

    Default

    Just a small thought, but does the green end up as coherent at the other end of the wheel as well? Or does it have a certain amount of scatter?

    If it does, DPSS is about to drop in price. Fast.

  5. #65
    Join Date
    Jun 2010
    Posts
    13

    Default

    ..for measuring that pulsed optical output: how about a thermal LPM? this will show the average optical power. with the (electrically measured) duty cycle we can then easily calculate the peak power. with such a low pulserate (250Hz) I would say its save to run those diodes in cw at their (in-projector) peakpower. sure, cooling is always a good idea.. which brings me to: how about someone watches some movies (if any projector still lives? *smiles*), maybe at the maximum of the roomtemperature stated in the manual, and measures the temperature of the laserblock? manuel (newhere, all excited etc) (edit: interesting my linebreaks for better readability are all gone..?)

  6. #66
    Join Date
    Oct 2006
    Location
    Central Florida
    Posts
    7,067

    Lightbulb

    You'd need a failrly big meter head to get all the light onto the sensor; I assume you mean the whole spectrum and not just the blue. Mo and I both have ours intact and plan to watch some video on it; he has a meter but I think the sensor is too small...
    Love, peace, and grease,

    allthat... aka: aaron@pangolin

  7. #67
    Join Date
    Jun 2010
    Posts
    13

    Default

    ..I was thinking about one of the beams, after the stock lens, with the other 23 diodes blocked. With the lens it should fit on a regular head? It shouldnt be difficult to find out how effective the stock lens is to get the raw-diode-numbers. Manuel

  8. #68
    Join Date
    May 2007
    Location
    Romania
    Posts
    1,041

  9. #69
    Join Date
    Oct 2006
    Location
    Central Florida
    Posts
    7,067

    Lightbulb

    Quote Originally Posted by andyf97 View Post
    What diameter is the big lens after the knife edging assembly?

    Check the link in this thread: http://www.photonlexicon.com/forums/...947#post147947

    It has pictures of the system taken apart; might be able to take some measurements of the lenses there.

  10. #70
    Join Date
    May 2008
    Location
    nerdtown, USA
    Posts
    1,165

    Default

    Quote Originally Posted by Stoney3K View Post
    Just a small thought, but does the green end up as coherent at the other end of the wheel as well? Or does it have a certain amount of scatter?
    Phosphorescence and stimulated emission are not the same process.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •