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  1. #26
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    Quote Originally Posted by Vancbiker View Post
    Keep in mind that the lead bike has the light pointed away from the camera, while the nice bright one is likely pointed at the camera.
    Quote Originally Posted by steelhmr View Post
    Independent of beam shot, lamp comparison, etc., that pic is beautiful.
    Of course, actual difference between lights is not as big as picture shows it (hence I've noted it as "advertising"), but in any case the light is quite bright. Our local bike club's members are using various powerful lights for long time, so they're familiar with most setups consisting several single- and dual-XMLs, but this one caused many jokes like calling me "landing aircraft" and "approaching locomotive"...

  2. #27
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    ahahah nice nicknames XD

    By the way a friend just told me to buy 3 of these that should give me the value of 0.050ohm Resistori SMD Resistenza basso ohm, 1206,0,33W,1%,R15 Panasonic ERJ8BSFR15V consegna in 24 ore , I guess I'll be even safer with the heat

  3. #28
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    How do you mean. Correct dimension, but putting three of those .15, corresponding to 0.05, will give you a much higher current than stock and a small-sized frying-pan

    Original
    1/(1/.25+1/.1+1/.33) = 0.906 and 16W

    The mod discussed above

    1/(1/.25+1/.1+1/.33+1/0.1) = 0.476 and 31W

    Yours?

    1/(1/.25+1/.1+1/.33+1/0.15+1/.15+1/.15)=0.032 and I guess ~45W!

    Quote Originally Posted by purifier82 View Post
    ahahah nice nicknames XD

    By the way a friend just told me to buy 3 of these that should give me the value of 0.050ohm Resistori SMD Resistenza basso ohm, 1206,0,33W,1%,R15 Panasonic ERJ8BSFR15V consegna in 24 ore , I guess I'll be even safer with the heat

  4. #29
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    Ouch some calculations errors I guess then
    Can you point me to the correct model on that website?

  5. #30
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    BTW, I misunderstood you. You are replacing the old resistors, all with a R15. All good then.

  6. #31
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    Quote Originally Posted by lofberg View Post
    BTW, I misunderstood you. You are replacing the old resistors, all with a R15. All good then.
    Yes, remove all the old ones and install 3 of these, proceeding to order them now

  7. #32
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    Awesome light after the mod. Unfortunately, it said bzzz after a couple of minutes (a couple of degrees above freezing outside, not moving just checking the light). Hadn't had the time to do any thermal management mods.

    The diod (marked ss34) popped off, and one leg of the coil hangs loose :-)

    To the lights defense, I was running it on a 12.5V LiPo battery. I've always run my lights on 3-cell LiPo and directly from motorcycle battery and never had any problems with this. I thought higher voltage simply meant lower current (within limits), but maybe that is not the case?

  8. #33
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    mmm sorry to hear that
    I've done (or rather, my friend has done) the mod and tested it only for a few seconds,
    now I gotta find a new battery for my old 35w HID spotlight to take a beamshot photo
    for comparison (that should be 3'500 lumens while this should output a little less), as for
    the bike ride I'll let you know if it lasts for a 40 minutes test lap...

  9. #34
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    Trying to learn these things from scratch (even installed spice to simulate boost drivers. yes I am an engineer...), so could someone correct me if I am wrong anywhere.

    1. The board uses a boost driver in order to increase incoming input voltage to ~25V for the 7 LEDs in series.

    2. The MOSFET switching is controlled by the QX5241. Datasheet here
    http://www.sddz-ic.com/upload/200962...3081632XYE.pdf

    3. Since the 5241 lists Vin as 5V-36V in its datasheet, a 12V (effectively 13.5V) battery should be no problems

    4. In the datasheet, it says I = 0.2/Rsense, so theoretically the LEDs should see 2.2A at nominal 0.0907Ohm. However, that makes no sense as the current goes over 7 LEDs in series, and that would be 50W. So, by guessing from the schematic in the datasheet and thinking CSN = current sense, the 5241 actually controls the *input* current on this lamp?

    5. The HT7133 simply supplies a constant 3.3V for auxilliary power on the board (the battery indicator led for example). I.e, it is not really involved in the boost process.

    What really confuses me is that I saw 2A when I ran the lamp on the 12V battery, i.e., what Archie noted on presumably original 8V battery since he stated 16W. Wouldn't the boost driver account for the higher voltage and thus require lower current? Or is my hunch above correct, the 5241 controls the input current, so a simple mod here is to simply run the lamp using a higher voltage battery (since the 5241 can accept that). Lines up with the fact that I saw 2A .

  10. #35
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    1,2 - Correct.
    3 - The power range of particular IC and working voltage limits of whole assembled light head are different things. Connecting the battery of significantly higher voltage is dangerous action in most cases, and this one is no exception.
    4 - Regulation circuit normally controls the power applied to the load, in turn, by adjusting power consumed from the energy source.
    5 - Correct.

    It's difficult to make "theoretical model" of what exactly happened to the light when you've simultaneously overvolted it and increased the current (especially without thermal management), but putting it simple, it's somewhat like plugging American 110v soldering iron into European 220v outlet. It surely will increase the temperature, but not for long...

  11. #36
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    Thank you for the answers.

    4 is what really confuses me, as the current draw on the source was the same regardless of input voltage, and increased proportionally when modding it. On my other lights, which work well under both 8V and 14V, the current drops proportionally when increasing the voltage. Could be that the control algorithm simply saturates somehow when running the light beyond the spec on input voltage.

    Anyhow, I liked the light, so I have a new on order (could not salvage the board, new schottky and resoldering the inductor did not help)

  12. #37
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    Yes, probably control circuit was already damaged by overvolting: otherwise, it should adjust input current according to the voltage. At least, all the bike lights I have are doing that, more or less successfully.

    Good luck modding the second unit, and don't forget to improve thermal sinking first!

  13. #38
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    I bought one based on this thread. It puts out about 1500 lumens out of the box comparing it w my Dinotte XML. I did the mod w 100 mohm and it then put out like a beast drowning out the dinotte. So far, so good. I then thermal pasted the led slug to the case, etc. You want the outer case to get hot. And it does get hot. I turned it on but got distracted for about 15 minutes. Oops. The light was off as well as the status light. There is no thermal shutdown on this. The clamp diode on the boost converter desoldered itself. The 100uf cap was blown. Inductor lead desoldered itself. Smell of burnt electronics, probably the cap. I'll repair what I can at work, but if the switch or controller are blown, I may need to get creative and design my own w/ thermal protection. LEDs looked ok.
    I don't know if the REAL lights are protected, but I won't be testing my dinotte in likewise fashion.
    Note to myself, these things need air flow

  14. #39
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    One more thing. I was worried about the case prior to blowing it up. It is handsome but is heavy and does not have much heatsink area. This may be why they keep the power down for the general masses?

  15. #40
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    I don't think so. Cooling is adequate if you're moving - I've tested that. IMHO, underpowering is implemented because of marginal batteries typically included with such lights: running on full power will exhaust them almost instantly...

  16. #41
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    A thermocam would be handy to get a visual of the driver components temperature. But the cheapest I found is about 200 EUR

  17. #42
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    That's a carbon copy of my melt-down

    Quote Originally Posted by dnitake View Post
    I bought one based on this thread. It puts out about 1500 lumens out of the box comparing it w my Dinotte XML. I did the mod w 100 mohm and it then put out like a beast drowning out the dinotte. So far, so good. I then thermal pasted the led slug to the case, etc. You want the outer case to get hot. And it does get hot. I turned it on but got distracted for about 15 minutes. Oops. The light was off as well as the status light. There is no thermal shutdown on this. The clamp diode on the boost converter desoldered itself. The 100uf cap was blown. Inductor lead desoldered itself. Smell of burnt electronics, probably the cap. I'll repair what I can at work, but if the switch or controller are blown, I may need to get creative and design my own w/ thermal protection. LEDs looked ok.
    I don't know if the REAL lights are protected, but I won't be testing my dinotte in likewise fashion.
    Note to myself, these things need air flow

  18. #43
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    Sorry lofberg,
    I missed the irony of your prior post. I'll try the repair a bit later.
    Anyways, DC/DC converters are power in/power out less efficiency usually 90% if the coil and switch are in their zones. So agree a higher voltage would be less current.

  19. #44
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    What irony? Anyway, just noting that our lamps went down exactly the same route when going up in smoke (cap, and desoldered diod+inductor).

    Quote Originally Posted by dnitake View Post
    Sorry lofberg,
    I missed the irony of your prior post. I'll try the repair a bit later.
    Anyways, DC/DC converters are power in/power out less efficiency usually 90% if the coil and switch are in their zones. So agree a higher voltage would be less current.

  20. #45
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    Archie,
    That was a good mod you did and I bet if I was moving it would be fine. Very informative. It makes having 7 LED's worth while, otherwise why bother.
    I wonder how Lupine does it at full tilt. For $1100 they can do a LOT of things.
    Bet it self protects.

  21. #46
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    Yes, Lupine actively adjust the current according to the temperature: it was mentioned many times. Many inexpensive lights also have thermal monitoring circuitry, but this one unfortunately does not: just be careful. Or add protection yourself, if you think it's absolutely necessary.

    As for the light, I'd say I really like it. After modding, I extensively use it on offroad rides: no problems so far, and very impressive output.

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