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Thread: Keep losing LOC Ideas?

  1. #1
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    Default Keep losing LOC Ideas?

    I have lost 3 LOC diodes in the past week, the replacements haven't lasted but about an hour each. There are three in series, all have LASORBs, it is always the first in the series to fail. I am using a 17v 4amp laptop supply and a flexmod.

    Any ideas seems so weird out of nowhere it is making them into LEDs.

    Thanks
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  2. #2
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    Being series wired, and the 1st goes each time, check for ground faults with your isolation on that particular diode housing.

    This is why I decided to wire mine in parallel with resistors to share current...
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    Quote Originally Posted by dnar View Post
    Being series wired, and the 1st goes each time, check for ground faults with your isolation on that particular diode housing.

    This is why I decided to wire mine in parallel with resistors to share current...
    I did even swap mounts and both are isolated on a meter. Also swapped Len's so I don;t think it is a reflection issue.
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    Quote Originally Posted by polishedball View Post
    I did even swap mounts and both are isolated on a meter. Also swapped Len's so I don;t think it is a reflection issue.
    Try soak testing without lens and the housing removed for a while, then add lens, then remount.
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    Quote Originally Posted by dnar View Post
    Try soak testing without lens and the housing removed for a while, then add lens, then remount.
    soak test? don;t know what that is.

    I am leaning towards a reflection back into it from the pbs as the cause.
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  6. #6
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    Quote Originally Posted by polishedball View Post
    soak test? don;t know what that is.

    I am leaning towards a reflection back into it from the pbs as the cause.
    Soak test is "engineerspeak" for run it well cooled, protected from dust, and safe at progressive power levels for long periods of time

    Steve

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    Quote Originally Posted by mixedgas View Post
    Soak test is "engineerspeak" for run it well cooled, protected from dust, and safe at progressive power levels for long periods of time

    Steve
    Correct, as apposed to testing it in a bucket of water!!!
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    Pretty sure Drlava and Heroic solved my issue last night. Somehow it is assumed there was a resonance in the circuit, added damping resistor and a cap across first diode been fine since.
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    Interesting.

    How have you wired to C/R, in series (Zobel network) or parallel?
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    Quote Originally Posted by polishedball View Post
    Pretty sure Drlava and Heroic solved my issue last night. Somehow it is assumed there was a resonance in the circuit, added damping resistor and a cap across first diode been fine since.
    Can you explain in a little more detail how you solved the problem? Maybe this is why we keep killing 445's when using Flexmods?

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