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  1. #1
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    dynamo voltage protection question

    Hi

    I have a new Shimano DH-3N80 dynamo and a 3W B&M LED front light (Lumotec IQ Cyo N plus). I only need a front light but bought the 3W dynamo for flexibility and in the hope that with more current being fed to it the LEDs would produce more light.

    So, can I plug the front light by itself to the dynamo without overvoltage protection? And will it be brighter than with a rear light?

    Tanks,
    tiago

  2. #2
    Zoom zoom zoom zoom bonk znomit's Avatar
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    Yes the Cyo will work fine with your dyno as is.

  3. #3
    coprolite fietsbob's Avatar
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    The added 0.6w load won't make it brighter, but it, wired in,
    will make it so you never forget to turn your taillight on.

  4. #4
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    OK, so if the extra 0.6V applied on the front light doesn't make it brighter then the corresponding power will be dissipated as heat. I will test and see it if gets "too" hot.

    Thanks

  5. #5
    Gear Hub fan
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    Quote Originally Posted by tiago View Post
    OK, so if the extra 0.6V applied on the front light doesn't make it brighter then the corresponding power will be dissipated as heat. I will test and see it if gets "too" hot.

    Thanks
    That is an extra 0.6 Watt, not volt. There are a couple of dynamo headlights that can use the extra juice. The Light On and the Supernova E3 Triple for sure. Both actually use more than 3 watts as they do not reach full light output till about 18 to 24 MPH. At that speed, depending on load impedence, a hub dynamo can be putting out a lot more than 3 watts.

    My Supernova E3 Triple instructions actually note that installation of the E3 taillight will reduce the light output of the E3 Triple headlight by about 10%.
    Gear Hubs Owned: Rohloff disc brake, SRAM iM9 disc brake, SRAM P5 freewheel, Sachs Torpedo 3 speed freewheel, NuVinci CVT, Shimano Alfine SG S-501, Sturmey Archer S5-2 Alloy. Other: 83 Colnago Super Record, Univega Via De Oro

    Visit and join the Yahoo Geared Hub Bikes group for support and links.
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  6. #6
    Velocommuter Commando Sirrus Rider's Avatar
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    Quote Originally Posted by znomit View Post
    Yes the Cyo will work fine with your dyno as is.
    Compared to the earlier model the IQ Fly the CYO has an external heat sink so it's more tolerant of the extra heat produced when running headlight only.
    Riding 19 Years of Specialized Sirrus Tradition.
    Live in Houston? Come to http://bicyclecommutehouston.blogspot.com/
    1988 Specialized Sirrus, 1989 Alpine Monitor Pass MTB, 2007 Specialized Sirrus 700C hybrid, 2007 Schwinn Town & Country trike, 1970 "Resto-Improved" Raleigh 20, 1970 "WIP" Raleigh 20, and 1980 "WIP" Schwinn Town & Country trike

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