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  1. #1
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    Possible driver issue?

    I just built up a dual XM-L, series - driven by an L-flex @ the 3A max. L2 is about at L3, and low is set at the actual L1 - ~50ma I think. Running in Threemode. Running off a 2S2P 4400ma pack.

    Everything seems fine, but I noticed that when you're on high, and do a long press to kick down to L1 (moonlight mode) that light actually goes dark, then gradually ramps up to the L1 brightness over about a second's timeframe. I also swear I'm seeing some PWM-like flicker as this happens. This is definitely not a major issue for me, as that situation would only happen while stopped. Clicking between Mid and Hi while riding has no issues.

    Anyone else seen this type of behavior?

    Here's a little video showing it - I click thru the modes for a bit, then the Hi -> L1 is at the end.

  2. #2
    Light freak
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    Sorry for the late reply, had to wait to get home from work to view the video as they block YouTube here at work.

    I have not seen that on any of builds with the LFlex. I am sure you have contacted George?



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  3. #3
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    Re: Possible driver issue?

    No I haven't. I probably should have, but if this was a normal thing I'd just be wasting his time. I'll drop him a line and see what he says.

    Sent from my cm_tenderloin using Tapatalk 2

  4. #4
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    Re: Possible driver issue?

    To clarify, I was in no way trying to call out TaskLED . George has been awesome to deal with over the years. I just haven't built but one other L-flex setup before, and I didn't remember it doing this. If you guys had told me this was normal, I'd be fine with it actually.

    Sent from my cm_tenderloin using Tapatalk 2

  5. #5
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    I have built up quite a few and have not seen that. Will be building up one this weekend, will let you know if I see it on that one.

    George is super helpful, don't hesitate to ask him any questions you may have.



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  6. #6
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    Re: Possible driver issue?

    Yah he has been emailing back and forth all morning now. I had another l flex that I ordered with the one that was misbehaving . He asked me to swap and send the first back to him.

    When I put the second driver in, it acts the same way. Now Im wondering if I have a battery pack that is doing something weird?

    I am using one of the magic shine 8.4 4400 packs as power source, maybe the transient is doing something weird.

    I have some loose Sanyo cells I can configure and see if that fixes it.

    Sent from my DROID RAZR using Tapatalk 2

  7. #7
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    Well - after some testing, my batteries seem to be fine. It is apparently an issue I've brought on by not having the driver thermally bonded to the casing during these short test runs.

    I wouldn't have guessed that a ~1minute at a time testing session would have been that problematic, but it appears that 2S leds run off a 2S fully charged pack really creates some heat quickly @ the driver. Board #2 cooked the mosfet

    No - I didn't have thermal protection turned on - that's my mistake, and one I'll learn from.

    I've switched back to driver #1, and AA'd it to a copper slug, then bonded that to the case with AA.

    we'll see how long that holds up.

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