Page 9 of 12 FirstFirst ... 56789101112 LastLast
Results 81 to 90 of 111

Thread: 445nm diode info

  1. #81
    Join Date
    May 2008
    Location
    nerdtown, USA
    Posts
    1,165

    Default

    Quote Originally Posted by -bart- View Post
    http://www.promodisc.com.br/NDB7352-E.pdf


    I saw this posted in another thread.
    I am almost certain this is NOT the diode Casio are using; they are pulsing them well above (2x) that absolute maximum If, and what's more, they are operating them considerably above the 30 deg C max operating temperature cited here.

  2. #82
    Join Date
    Nov 2005
    Location
    Melbourne, Australia
    Posts
    3,702

    Default

    Comparing the 9mm Nichia diode to the Casio diodes I have , the beam characteristics are identical.

    I think Nichia greatly under exaggerate the power of their diodes, hence why everybody runs the 50mw 445nm diode at 150mw
    KVANT Australian projector sales
    https://www.facebook.com/kvantaus/

    Lasershowparts- Laser Parts at great prices
    https://www.facebook.com/lasershowparts/

  3. #83
    Join Date
    May 2008
    Location
    nerdtown, USA
    Posts
    1,165

    Default

    Quote Originally Posted by dave View Post
    Comparing the 9mm Nichia diode to the Casio diodes I have , the beam characteristics are identical.
    They're probably the same resonator design; doesn't mean they have the same package bond, max temperature or thermal rejection capacity.

  4. #84
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,446

    Thumbs down

    Following mpoulton's example, I deleted my off-topic rant.

    Adam
    Last edited by buffo; 07-07-2010 at 10:35. Reason: off-topic

  5. #85
    Join Date
    Jun 2010
    Posts
    48

    Default Diode thermal tolerance

    I have previously noted that these lasers are quite heat sensitive. They are permanently damaged by only a few seconds' operation without a heatsink, or by several seconds of sustained soldering. Others have noted, however, that these are run at rather high temperature in the Casio projectors. Here's one bit of information that I haven't seen noted anywhere yet:

    The Casio projectors have a 100C thermal switch on the laser heatsink. They do not appear to have any other form of temperature monitoring for the array. Thus, we can probably assume that operation with a case temperature up to 100C will not cause instant damage.

    In the interest of trying to save this important thread, which was to be dedicated to technical info only, without questions, discussion, or off-topic conversation, I am deleting my prior off-topic post. Maybe we can salvage this?

  6. #86
    Join Date
    May 2009
    Location
    UCSB
    Posts
    715

    Default

    There are 2 small 10k NTC resistors inside the diode array. If you remove the flexible circuit board from the diodes there are 2 pink pieces of foam inside the array which sit on on 2 0603 sized SMD parts, these are both thermistors.

    I don't have a working projector anymore, but I would assume the 100C thermal switch is a 'last resort' emergency shutdown, and that the normal temperature monitoring is done by the thermistors. Does anyone have the ability to mount a thermocouple on the diode array and let the projector run until it goes into overheat shutdown?

  7. #87
    Join Date
    May 2008
    Location
    nerdtown, USA
    Posts
    1,165

    Default

    On my quad, I notice a gradual drop in power, from 7.2 watts at 22 deg C, to 6.5 watts at a heatsink temperature of 48 deg C.

    This drop does not appear to be permanent and the power comes right back as soon as I drop the mod, let it cool for a few seconds, and throttle back up.

  8. #88
    Join Date
    Jun 2010
    Posts
    48

    Default

    Quote Originally Posted by krazer View Post
    There are 2 small 10k NTC resistors inside the diode array. If you remove the flexible circuit board from the diodes there are 2 pink pieces of foam inside the array which sit on on 2 0603 sized SMD parts, these are both thermistors.

    I don't have a working projector anymore, but I would assume the 100C thermal switch is a 'last resort' emergency shutdown, and that the normal temperature monitoring is done by the thermistors. Does anyone have the ability to mount a thermocouple on the diode array and let the projector run until it goes into overheat shutdown?
    Ha! Good call. I hadn't looked carefully enough at the contents of that flex board. The choice of a 100C switch probably still means that a brief 100C excursion is survivable though.

    I can run that test, but I'm a bit reluctant to risk 24 lasers to do it. I just stripped out the last of the arrays I have right now (an hour ago I had four...) but when I get my next order later this week, I may thermocouple one up and give it a shot.

  9. #89
    Join Date
    Jul 2008
    Posts
    108

    Default Z-Bolt

    Quote Originally Posted by lasersbee View Post
    It is mounted in a Z-Bolt clam shell heat sink..
    Jerry
    Hi. What is a Z-Bolt clam shell heat sink?

    Thanks!

    -Franken

  10. #90
    Join Date
    May 2009
    Location
    UCSB
    Posts
    715

    Default

    And for people that don't have the ability to see into the past before said item was discontinued, its a heatsink that you can bolt onto a normal 12mm diode housing

    from http://www.photonlexicon.com/forums/...hp/t-7305.html

Posting Permissions

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