Page 1 of 7 12345 ... LastLast
Results 1 to 10 of 63

Thread: Why did my 642nm diode die?

  1. #1
    Join Date
    Oct 2009
    Location
    Perth Western Australia
    Posts
    844

    Question Why did my 642nm diode die?

    Hi guys,

    Well I just paid some of my dues on my right of passage to laser wisdom

    I just killed my first Opnext HL6385DG diode


    I'm using 3x Die4drive Pros on my little RGB test rig and all is well for my green and blue. I started out using a cheap Mitsubishi ML101J27 658nm to get the hang of things and that worked fine.(Thanks Dave)

    I've heard about the 642nm diodes being fragile so I used a properly grounded matt and wrist strap to be safe.

    I insulated the diode from the baseplate with insulating matt and plastic bushes for the screws.

    Everything was going well after I powered it on. I ramped the current up to about 140mA and collimated the beam to a nice dot at approximately 1m with one of McCarrot's red coated lenses and mounted in Dave's diode mount.

    I slowly ramped up to approximately 200mA and the beam suddenly went from a dot to a horizontal line/fan about 40mm wide (on the wall, 1m from the aperture).

    This line initially had several hot spots then gradually faded in intensity.

    Now it is just a faint messy beam

    Sound familiar?

    Any ideas on what I could have done wrong?

    I hooked up the previously working 658nm diode and it worked fine using the same driver.

    does this sound like a static induced death or something else?

    Any advice from the wise and battle scared elders would be appreciated.

    I'm on my first tour of duty and I copped a flesh wound. I'm a bit chicken to climb out of my trench and charge with my remaining 642nm diode
    Help........

    Edit... I should mention that I'm using Adam's laser bugs. However Only the blue one has a lasorb fitted as he was out of red lasorbs when I bought them.
    Attached Thumbnails Attached Thumbnails IMG_0057-1.jpeg  

    IMG_0058.jpeg  

    IMG_0059.jpeg  

    Last edited by kitatit; 04-17-2011 at 00:06. Reason: more info

  2. #2
    Join Date
    Sep 2006
    Location
    Netherlands
    Posts
    1,435

    Default

    Sounds like a typical case of cod to me.
    Could be anything, really.

    Apart from using a wrist-strap, make sure your workspace is free from all kind of stuff that could store charge too. Like plastic bags, packing material, and so on.

  3. #3
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,248

    Default

    What is the recommended current for the Opnext? Were you over it?
    Frikkin Lasers
    http://www.frikkinlasers.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  4. #4
    Join Date
    Oct 2009
    Location
    Perth Western Australia
    Posts
    844

    Default

    Quote Originally Posted by -bart- View Post
    Sounds like a typical case of cod to me.
    Could be anything, really.

    Apart from using a wrist-strap, make sure your workspace is free from all kind of stuff that could store charge too. Like plastic bags, packing material, and so on.
    Thanks Bart I'll try again with a bit more care.

    Quote Originally Posted by norty303 View Post
    What is the recommended current for the Opnext? Were you over it?
    I don't have the spec sheet with me atm but I'm pretty sure it operation current is 280mA

  5. #5
    Join Date
    Aug 2008
    Location
    UK
    Posts
    5,704

    Default

    Looks like max is 350ma according to this data sheet:

    http://www.opnext.com/products/pdf/o...1_hl6385dg.pdf

    What was the voltage at though as MAX is 3 volts only.

    Can't offer any advice as I know zero about building.

  6. #6
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,890

    Default

    I'm sorry for your loss.

    The Opnext diodes are really tough. If the diode was heatsinked properly with no optics in front of it, I would check your driver with a test load. Get a lasorb in case you have a spike in your PSU output. As the world has switched over to switching power supplies, it has gotten harder and harder to get clean power. If you have a scope, check your supply voltage for spikes. Many switchers appear to me to need external filtering.

    Steve

  7. #7
    Join Date
    Jul 2007
    Location
    west sussex uk
    Posts
    2,280

    Default sorry for your loss

    i too have lost two to the LED gods and no idea why ,proberly back reflection
    but the remaining four are ok and happy running at a modulated 350ma
    When God said “Let there be light” he surely must have meant perfectly coherent light.

  8. #8
    Join Date
    Jun 2010
    Location
    Australia
    Posts
    3,734

    Default

    Kit, I feel your loss man.

    How about a good macro photo of the corpse?
    This space for rent.

  9. #9
    Join Date
    Oct 2009
    Location
    Perth Western Australia
    Posts
    844

    Default

    Quote Originally Posted by White-Light View Post
    What was the voltage at though as MAX is 3 volts only.
    I don't know, I thought this driver took care of it.... the instructions don't make any note of voltage and how it can be set. After that statement it should be pretty clear how much I understand about the finer details of how diode drivers or most circuits work

    Quote Originally Posted by mixedgas View Post
    I'm sorry for your loss.

    The Opnext diodes are really tough. If the diode was heatsinked properly with no optics in front of it, I would check your driver with a test load. Get a lasorb in case you have a spike in your PSU output. As the world has switched over to switching power supplies, it has gotten harder and harder to get clean power. If you have a scope, check your supply voltage for spikes. Many switchers appear to me to need external filtering.

    Steve
    Thanks for the clues Steve after thinking about your tips I'll have to resist my urge to be an impatient wipper snapper and wait to get the right gear. I'll buy some red lasorbs and a scope. I've just been speaking to Dnar and I think I'm set on buying a Rigol. I'll report back in a week or two

    Quote Originally Posted by dnar View Post
    Kit, I feel your loss man.

    How about a good macro photo of the corpse?
    Yeah I can think of a few things I could have spent that money on but learning about lasers is priceless. I wasn't to surprised considering I'm a bit of a hack at electronics. Well a least I've got my "blown expensive diode" badge
    now

    It wouldn't be right if a punk kid could just walk in and get his laser working first time

    Thanks for your advice
    Kit

  10. #10
    Join Date
    Nov 2005
    Location
    Melbourne, Australia
    Posts
    3,702

    Default

    Quote Originally Posted by White-Light View Post
    What was the voltage at though as MAX is 3 volts only.

    Can't offer any advice as I know zero about building.
    Its a constant current driver - you set the current and the voltage takes care of its self.
    KVANT Australian projector sales
    https://www.facebook.com/kvantaus/

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

Posting Permissions

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