Results 1 to 8 of 8

Thread: LASORB and 2 diodes

  1. #1
    Join Date
    Apr 2010
    Location
    Grand Rapids, Mi
    Posts
    2,433

    Default LASORB and 2 diodes

    If you run 2 diodes in series can you use a single Lasorb across them both? anode of one and cathode of the other? Curious if this would work. I have more on order, but have had awful luck with the red sled diodes when not protected, and I have the itch to play.
    leading in trailing technology

  2. #2
    Join Date
    Jan 2006
    Location
    Switzerland
    Posts
    129

    Default

    No that won't work at all! The Lasorb cuts off a tad above the forward voltage of a single diode, so it does not support the voltage of two diodes.

  3. #3
    Join Date
    Sep 2008
    Location
    Orlando, Florida
    Posts
    1,023

    Default

    Interesting. I have two red LOC's in parallel with one lasorb. Are you telling me it isn't doing anything? Do I need to simply put another lasorb on the other laser or do I need to seperate them for it to work?

    Lazerjock

  4. #4
    Join Date
    Dec 2008
    Location
    Vezon, Belgium
    Posts
    1,017

    Default

    two red diodes should work with a blue lasorb, no?

  5. #5
    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
    9,186

    Default

    Quote Originally Posted by Lazerjock View Post
    Interesting. I have two red LOC's in parallel with one lasorb. Are you telling me it isn't doing anything? Do I need to simply put another lasorb on the other laser or do I need to seperate them for it to work?

    Lazerjock
    using made up numbers:

    Yours are in parallel, so no problem, ie 2.2 volts or so Vdiode. His are in series, so 4.4 volts across the lasorb and its starting to trip. The lasorb probably is set to trip at two times V diode.

    Steve
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  6. #6
    Join Date
    Jan 2006
    Location
    Switzerland
    Posts
    129

    Default

    Quote Originally Posted by Lazerjock View Post
    Interesting. I have two red LOC's in parallel with one lasorb. Are you telling me it isn't doing anything? Do I need to simply put another lasorb on the other laser or do I need to seperate them for it to work?
    No, what I wrote was for diodes in series, not in parallel. For parallel diodes that is in principle be ok but in practice running diodes parallel is a bad idea! There is no reason why they would share the current equally, and if they don't, one diode may run beyond specs. For running diodes in parallel one should at least add current balancing resistors, but that may be in conflict with using one Lasorb for both.


    Whether it works with a blue Lasorb depends on whether the combined forward voltage is larger (bad) or less (good) of the blue lasorb voltage, and this depends on the diodes and the current. It is roughly in the right ballpark, though.

    PS: to be precise. An open can diode has forward voltage between 2.2 and 3V. A red lasorb has cutoff voltage of 3.2Vmax and a blue one of 7.5V max. This means for two diodes in series one needs 4.4-6V and this fits well to a blue lasorb indeed.
    Last edited by RedlumX; 09-11-2010 at 08:25. Reason: data added

  7. #7
    Join Date
    Sep 2008
    Location
    Orlando, Florida
    Posts
    1,023

    Default

    Thanks for all of the information. I'm sorry for not seeing that you were running in series.
    Lazerjock

  8. #8
    Join Date
    Oct 2007
    Location
    Wisconsin
    Posts
    305

    Default

    The Lasorb's function relies on an ultra low resistance between the connections between it and the laser diode, typically it is soldered right onto the end of the diode's leads.

    It would take a very good low ohm connection to go between two diodes in series or having them physically next to each other and soldered lead to lead with the lasorb on the outside lead.

    An optical rearangement to save eight bucks?

    I just ordered a bunch of these for blue.

Posting Permissions

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