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Thread: ttl blanking - wow got me worried

  1. #11
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    Quote Originally Posted by dave321
    looks like thats sorted the problem out , excellent !! thanks a lot
    dave
    Great news 8)
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  2. #12
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    Man, I've been an idiot recently... I completely missed this thread.... Ok... here we go.

    Yea, its been while since ive played with a FYOE laser and i do remember the blanking being "non standard/Inverted".

    With all "real" lasers you have to apply a voltage to slap the opto coupler into shorting/limiting the lead. with these things, its just looking for a deadshort to reroute the diode current. pretty dangerous stuff as far as the DAC's life is concerned.

    Chinese lasers are notoriously bad for these type designs.

    Sorry I missed the thread like an idiot, ill try to get my brain working again.

  3. #13
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    I re-open this post

    I have this laser too, with TTL modulation only (I have 2 wires for blanking).
    But Liteglow, you have the same laser but with ANALOG blanking?

    Is it possible (and easy) to change my laser blanking to analog? I definitely need an analog blanking to correctly mix with my red laser

  4. #14
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    Hi..
    I dont think that my laser was analog... :?
    I did only belive so becouse of the strange way it did behave when I did connect it to analog signal ... (as I never in my life had seen ANALOG blanking, i did not know better)

    But today I know that it was not analog blanking, only a "strange" thing going on..

    But I did blow my TTL stuff inside my green laser :roll:
    So today it`s only *ON* ... and never off lol
    Dont know what to use it for...

  5. #15
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    Ok... And you can't repair the TTL system? Basically it's only an optocoupler, maybe it's just this that's dead...

    I see how TTL blanking works, but I don't see how analog works... Maybe if I know it, I can modify my circuit to achieve analog!
    What is modulated? Directly the pump diode current? And with which component? An optocoupler is only on-off, as far I know...

  6. #16
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    i dunno if I can fix it ?
    I did never care anyway...

    First there was some problems with the TTL..
    Then I think I did blow the circuit, the laser did go BLANK !! no output..

    Then I slowly adjusted the volt from 3volt and up to 4.. nothing happend..
    5volt.. notting happend.. 7....9...12volt noting... THEN at 20volt :twisted:
    there was some black smoke from the TTL circuit, and the laser did go ON :twisted: ..

    And the funny thing is that it`s still on working like a dream
    without the Blanking....... :roll:

  7. #17
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    Lol...

    I think you blow the optocoupler's phototransistor or diode with the 20V voltage, but why the laser woke up when the TTL smoked?

    I will try to reverse engineer the blanking circuit, and if I discover some interesting things, you will be advertised

    But you can still look if there is an optocoupler somewhere in the circuit, and verify it...

  8. #18
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    I will try to take some macro pictures when I got the time

  9. #19
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    I discovered that I have 3 pins for the blanking, and only 2 are used...
    First I wondered that maybe it was analog blanking But no, the third pin is reverse blanking :evil:

    The blanking circuit is a SMD circuit, and so not so easy to reverse engineer...
    Pfff, who want a >200mW laser TTL for a few bucks, so I can buy a real analog dpss?

  10. #20
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    @ sbk
    What colour is it and how much are you after?

    Jim

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