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Thread: blue leakage

  1. #1
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    Default blue leakage

    at ilde, the 455 diode emits a very faint amount of light that is absolutely minor but shows up in photographs of scanned graphics. Using a die4drive. Any ideas on how to eliminate the blue leakage?

  2. #2
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    Quote Originally Posted by Zoof View Post
    at ilde, the 455 diode emits a very faint amount of light that is absolutely minor but shows up in photographs of scanned graphics. Using a die4drive. Any ideas on how to eliminate the blue leakage?
    If you have version 1.2 there's supposed to be an offset pot R2...

  3. #3
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    That doesn't really help. The issue is that the diodes light up before they actually fully lase so if you set your threshold just below lasing, as typically done, you have a blue light. If you lower the threshold until it is no longer lit up you end up with a region where it glows but doesn't lase, and that's pretty useless. You can compensate for all of that in software but it doesn't make for the best modulation.

  4. #4
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    Use the shutter (or intensity?) signal to completely kill the diode current, so you have zero current when the shutter is "closed", idle current when the shutter is open but modulation is at zero and full current when the shutter is open and full modulation is applied.

    As long as the software can be set to do the right thing with the shutter or intensity signal this should solve this.

    Regards, Dan.

  5. #5
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    I guess that works if you have a shutter.

  6. #6
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    Doesn't need to be a mechanical shutter, just modify the current source to pay attention to the appropriate signal from the ILDA connector.

    Regards, Dan.

  7. #7
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    just modify the current source to pay attention to the appropriate signal from the ILDA connector.
    That would be a nice one for the flexmod P4.

  8. #8
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    I did find this also annoying and made a driver (IceBrick DRV) specially for the blue diodes. Currently waiting for the prototype PCB to arrive and start testing if it works ok or not. It should arrive soon because I'm waiting a few weeks already



    The driver has 2 outputs and the bias current will be disabled when no signal is applied on the (shared) input.

  9. #9
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    Nice, order a couple of extra for me if you can

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