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Thread: 405nm again again again

  1. #21
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    Oct 2006
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    Central Florida
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    Question

    6x will take over 200mA!!! I guess the 120mA I have going to mine will make it last for a LONG time. May have to turn that POT up some.

  2. #22
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    Default

    120mA will give a diode life ad infinitum.
    But I like to push mine a bit further, keep them living on the edge (or a suitable plateau that looks scary ).
    When you hit around 200mA, be careful as you're just getting into degrading life territory. 220mA is as much as I'd go for a reasonable life span.
    You can find out if you are damaging the diode. First (with your 120mA diode) take the current down to zero, then slowly increase the current until it just starts to lase. Make a note of this threshold current. Then when you've been dabbling with higher currents, recheck the threshold current. If it's moved up a bit, you're shortening the diode life quite a bit with whatever current you had previously run. That is the time to back things off a little. The slope efficiency of the 405's remains pretty much constant, no matter what abuse you throw its way. However, at least from my observations, the only tell tale sign is to monitor the threshold current now and then, when experimenting with high powers.

    On the other hand, the red diode in the 6x sled, will readily take 420mA pumping out close to 250mW. But that's a whole different kettle of fish.

    Hope that helps,

    Dan
    Last edited by danielbriggs; 01-19-2009 at 07:08.

  3. #23
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    Lightbulb

    I was told the red in there is also a fairly good diode. I just got a dual blu-ray set up for my projector with a 4x and 6x that we are combining. It seems it maybe underpowered on one side now... The 4x is at 100mA and 75mW and the 6x is at 120mA and 100mW. Combined they are producing 140mW due to a 10+% loss on a mirror and the transmit of the cube might need tweaking, it is losing close to 10% also. I might need to take the set back to have the 6x turned up to 175 or something. I use my projector A LOT and want to keep the diodes fairly comfortable so they hang around a while.

    I am about to go out and get a PSU for the set. The "creator" had a test supply but for some reason it needs 7.5 volts DC, and... that happens to be one voltage I don't have a supply for. Off to SkyCraft. Anyone else need anything?

  4. #24
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    Default

    Bah! I would have a field day tuning that rig up to almost double, while keeping a long life on the pair.
    Personally, I'd set your 4x and 6x to 150mA and 200mA respectively, open up the back of the lens thread (acrylic), and get a >98% FS mirror to minimise losses there. Then I reckon you should get almost double, perhaps close to 280/300mW.
    A decent heatsink, with good thermal contact on the diode is a given.

    However all diodes vary slightly, so proceed with caution!

    Dan

  5. #25
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    Oct 2006
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    Central Florida
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    Default

    Here is the album I made for the dual blu-ray. I have installed it into my projector but still need to make a wire for the violet color channel from myt QM2000. I have this awesome, "custom" ILDA brakout board, but it only has R, G, and B dolor connections... I have to solder wires onto a ILDA plug for the "missing" color channel(s)...

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