Page 2 of 4 FirstFirst 1234 LastLast
Results 11 to 20 of 38

Thread: Breaking diodes? How easy is it?

  1. #11
    Join Date
    Dec 2008
    Location
    Southport, UK
    Posts
    2,746

    Default

    ... as already mentioned above; before you plug in your fresh diode make sure you short out the driver.

    The capacitor on the board will blow the arse out of the diode if the driver has been previously powered with an open circuit diode.
    http://img62.imageshack.us/img62/3985/laser.gif

    Doc's website

    The Health and Safety Act 1971

    Recklessly interfering with Darwin’s natural selection process, thereby extending the life cycle of dim-witted ignorami; thus perpetuating and magnifying the danger to us all, by enabling them to breed and walk amongst us, our children and loved ones.





  2. #12
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,248

    Default

    ... as already mentioned above; before you plug in your fresh diode make sure you short out the driver.

    The capacitor on the board will blow the arse out of the diode if the driver has been previously powered with an open circuit diode.
    This 'could' be the problem, although i can't rightly remember the order of events now.
    That said, I can't remember actually running the driver without anything attached as I wasn't sure if this would damage it - it always had a diode or a meter attached.

  3. #13
    Join Date
    Dec 2008
    Location
    Southport, UK
    Posts
    2,746

    Default

    Even if you didn't power it, capacitors can and do just obtain a charge (unless they are shorted with a bleeder resistor).

    http://www.zpenergy.com/modules.php?...ticle&sid=2230
    http://img62.imageshack.us/img62/3985/laser.gif

    Doc's website

    The Health and Safety Act 1971

    Recklessly interfering with Darwin’s natural selection process, thereby extending the life cycle of dim-witted ignorami; thus perpetuating and magnifying the danger to us all, by enabling them to breed and walk amongst us, our children and loved ones.





  4. #14
    Join Date
    Apr 2008
    Location
    Amsterdam, NL
    Posts
    2,098

    Default

    Quote Originally Posted by ElektroFreak View Post
    Just be careful with those diode sockets.. I know they're made by Thorlabs, but I've never been a fan. They make me nervous since the diode could move slightly while in operation. Even the action of the diode pin sliding along the contacts in the socket can cause lethal transients if contact is lost even for a millisecond.. I firmly believe that diode connections should be securely soldered.
    Could not agree more!


    Quote Originally Posted by ElektroFreak View Post
    I popped one while it was attached to a Flexmod. A voltage transient occurred when I plugged the 5V supply into the wall. Since I was using the same supply to give 5V on the modulation input I think the transient traveled to the diode through the modulation input, but I'm not 100% sure of that.
    I have killed many diodes this way, nice working laser, pulled the main plug, put the laser back on power and death diode
    Since I switch off the 5V with the interlock instead of the mains I never had a problem with killed diodes.

    Diodes are pretty rugged, twice I dropped a open can on the floor and they still work fine. Last week we tested a quad setup and during harvesting we havily damged the can, the diode was suprisingly enough still working fine.

    A friend of mine killed a few diodes during soldering, but when he showed me how he did it I was not supprised. he used a cold soldering iron and he was baking the pins for 10-20 seconds yes this will kill the diode. But have soldered many diodes and never killed one during soldering.

  5. #15
    Join Date
    Apr 2008
    Location
    Amsterdam, NL
    Posts
    2,098

    Default

    Quote Originally Posted by Doc View Post
    Even if you didn't power it, capacitors can and do just obtain a charge (unless they are shorted with a bleeder resistor).

    http://www.zpenergy.com/modules.php?...ticle&sid=2230
    Most drivers got a capacitor on the output, maybe its whise to add a 100k resistor paralel over the capicitor so it can never be or kept charged.

  6. #16
    Join Date
    Feb 2009
    Location
    Bedfordshire
    Posts
    46

    Default

    Quote Originally Posted by ElektroFreak View Post
    Just be careful with those diode sockets.. I know they're made by Thorlabs, but I've never been a fan. They make me nervous since the diode could move slightly while in operation. Even the action of the diode pin sliding along the contacts in the socket can cause lethal transients if contact is lost even for a millisecond.. I firmly believe that diode connections should be securely soldered.
    I have tried similar diode sockets from Roithner, (another highly respected supplier of course), and have had diodes fail for the very reasons mentioned above. Took a couple to realise what was happening... Slight movement; disconnection; capacitor charges; reconnection; capacitor discharges; diode goes poof! All so quick it looks like the diode just stops lasing. I will never, ever use them again.

    M

  7. #17
    Join Date
    Dec 2008
    Location
    Vezon, Belgium
    Posts
    1,017

    Default

    there is also another way to fry them

    soldering them with a line-connected iron when your line is full of transients

    my parents house was located next to a cement plant, not to mention it also was 5 meters away from the distribution transformer

    the line was so full of shit we could see transients in lamps brightness!

    since then I have moved to another location and live on my own, and no more transient problems

    soldering with a noisy line and bad earthing of your network may do the same as striking a tesla coil at your diode

    what I did to solve this problem was heating the iron on line, then disconnect it to solder the diode, and never had any failure

  8. #18
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,248

    Default

    Well it turns out it IS actually quite hard to kill them! Now working fine after I checked it out a bit better and noticed that all the solder residue left on the pins was really dull. I cleaned and re-tinned the pins and they went noticeably further home on the diode socket this time - powered up - we have coherent light!

    Now I just wish the postman would bring my mini mounts from Pat and the world will be a happier place.

  9. #19
    Join Date
    Apr 2010
    Location
    Grand Rapids, Mi
    Posts
    2,538

    Default

    Quote Originally Posted by norty303 View Post
    Well it turns out it IS actually quite hard to kill them! Now working fine after I checked it out a bit better and noticed that all the solder residue left on the pins was really dull. I cleaned and re-tinned the pins and they went noticeably further home on the diode socket this time - powered up - we have coherent light!

    Now I just wish the postman would bring my mini mounts from Pat and the world will be a happier place.
    Glad you got it working
    leading in trailing technology

  10. #20
    Join Date
    Dec 2008
    Location
    Southport, UK
    Posts
    2,746

    Default

    Quote Originally Posted by norty303 View Post
    Well it turns out it IS actually quite hard to kill them! Now working fine after I checked it out a bit better and noticed that all the solder residue left on the pins was really dull. I cleaned and re-tinned the pins and they went noticeably further home on the diode socket this time - powered up - we have coherent light!

    Now I just wish the postman would bring my mini mounts from Pat and the world will be a happier place.
    Good news!

    Soon it will be play time and you can have a blister on your focus adjusting thumb too.
    http://img62.imageshack.us/img62/3985/laser.gif

    Doc's website

    The Health and Safety Act 1971

    Recklessly interfering with Darwin’s natural selection process, thereby extending the life cycle of dim-witted ignorami; thus perpetuating and magnifying the danger to us all, by enabling them to breed and walk amongst us, our children and loved ones.





Posting Permissions

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