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  1. #1
    Flashaholic* Martin's Avatar
    Join Date
    Apr 2006
    Location
    Germany
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    584

    Default Charging portable equipment from a bicycle hub dynamo

    Not exactly a light project, still something CPF members regularly ask for.
    During my visit to Eurobike, I saw 3 products that enable the rider to charge a mobile phone, GPS, ... from energy that the dynamo delivers.

    1) Busch & Mueller "E-WERK" (Germany)
    Input is dynamo, output delivers 2.8 - 13.3 V, 0.1 - 1.5 A.
    Voltage and current limits are user-adjustable, making the unit highly flexible (assuming the user understands that wrong settings can burn his iPod)
    The unit can run in parallel with dynamo light systems but will reduce the light output.

    2) Tout-Terrain "The Plug" (Germany)
    A 5V USB power supply that fits into the steerer tube.

    3) PedalPower+ (Australia)
    - PP+ DC output hub dynamo 5V / 600mA
    - PP+ AC Universal Cable (fits any regular dynamo, AC hub or bottle types), 5V / 600mA
    - Various standard accessories that feed on USB power. Includes solar cell + rechargeable battery units.

  2. #2

    Str Re: Charging portable equipment from a bicycle hub dynamo

    Nice .......................

    but ... i would rather have the dynamo charging a "battery" of yr choice first then ... use the "battery" to charge or power the equipments

    as there will be a risk of over voltage charging the equipments.
    thats the old method i knew ....

    thus ........... its wiser to use the

    3) PedalPower+ (Australia)
    - PP+ DC output hub dynamo 5V / 600mA
    - PP+ AC Universal Cable (fits any regular dynamo, AC hub or bottle types), 5V / 600mA
    - Various standard accessories that feed on USB power. Includes solar cell + rechargeable battery units.

    have fun with yr project!
    Last edited by roadie; 09-13-2009 at 04:11 AM.

  3. #3

    Default Re: Charging portable equipment from a bicycle hub dynamo

    oh err further reading and thinking ... the aus hub does not comes with a disk brake mount, thus it will use the older way of brakiing ... v-brakes or caliper brakes instead.

    and it came with 36 spokes instead of the norm 32 spokes, so beware of the spokes hole on the existing rim or new rim when u get them for wheel building with the new dynamo hub, note ......

    btw also, the charge is 6 V, note ....


  4. #4
    Enlightened
    Join Date
    Sep 2007
    Location
    Weaver, AL
    Posts
    86

    Default Re: Charging portable equipment from a bicycle hub dynamo

    Here is a very simple circuit I use to power/charge a USB device like a GPS unit or Cell Phone.

    Rising internal impedance of the batteries above 4.8 volts limits dynamo voltage to 5.2 volts DC. This is within USB power standards. USB devices are limited to 500 mA which happens to be the output of a standard bicycle dynamo. If the USB device uses less than 500 mA the excess current will be absorbed as recharging current. The Ni-MH batteries must have solder tabs and soldered connections. Any poor or open connection between the batteries would allow unregulated voltage and current to flow into the USB device which could seriously damage it. The Circuit shown includes a separate headlight circuit shown in a simple form. Any standard dynamo headlight or one of Martins LED light circuits may replace the simple circuit shown. The Dynamo can not power the USB circuit and the Headlight at the same time. If you need to turn on the headlight while a USB device is plugged into the USB port such as when traveling through a tunnel the Ni-MH batteries will continue to power the USB device limited by the current requirements of the device. If you do not need/want a headlight it may be left out of the circuit.

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