Charging appliances using dynamo

Discussion in 'UK and Europe' started by Julian, Mar 2, 2004.

  1. Julian

    Julian Guest

    Has anyone come across a straightforward solution to this rather modern cycling problem?

    When I go cycle touring I could simply stay out of touch, not take any pictures, use pieces of
    paper and get lost but the fact is that I want my mobile, my digital camera, my Palm and possibly
    a GPS with me when I go away. All of these have rather short useful lives in the absence of a
    method of recharging them. I could of course stay in hotels or hire a car to get access to
    electricity but why?

    Of course I have managed in the past without any of this and had many happy cycling tours, but you
    just do get used to having certain stuff around and requirements change.

    I do have a Schmidt hub which produces leg powered electricity for very little effort and I read
    that most of these electronic gadgets can be charged to a reasonable extent in about half an
    hours cycling.

    The only trouble is that no-one seems to produce a really suitable charging cable to allow me to use
    my leg power to charge my gadgets. There is a "Pedal and Power" thing available at
    http://www.ikonglobal.com/readme.htm but this includes lots of unnecessary bits that I don't want -
    all I need is a cable, socket and power management.

    I believe that in Holland Mobile Phone companies are providing free units for anyone taking out a
    phone contract.

    Does anyone know anything about these or any other sensible solutions that do not involve soldering
    irons and electronics degrees?

    Julian

    [remove s from email address to despam]

    __o
    _`\(,_
    (_)/ (_)
     
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  2. > The only trouble is that no-one seems to produce a really suitable charging cable to allow me to
    > use my leg power to charge my gadgets. There is a "Pedal and Power" thing available at
    > http://www.ikonglobal.com/readme.htm but this includes lots of unnecessary bits that I don't want
    > - all I need is a cable, socket and power management.

    Does anyone use one of these? Are they any good?

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  3. Arthur Clune

    Arthur Clune Guest

    Julian <[email protected]> wrote:
    : Has anyone come across a straightforward solution to this rather modern cycling problem?

    It's a standand gizmo that gets re-invented every few years, along with direct drive and
    regenerative braking, and fails for the same reasons they do.

    Your Schmit will produce 3W. 6W if you get the new one. The latter might be useful to charge
    something small, but you'll have to step the voltage to whatever the thing wants, losing power, and
    indeed, your step will have to deal with lots of different voltages AC v DC and all the rest (more
    waste of power). And the real problem is that humans don't have that much power to start with.

    My mobile lasts a week on a charge and charges in 2-3 hours. Surely once a week you'll find a
    campsite/pub/cage that will let you charge a mobile?

    Arthur

    --
    Arthur Clune http://www.clune.org "Technolibertarians make a philosophy out of a personality defect"
    - Paulina Borsook
     
  4. > My mobile lasts a week on a charge and charges in 2-3 hours. Surely once a week you'll find a
    > campsite/pub/cage that will let you charge a mobile?

    That's a good point. I was thinking about using it to power a mobile phone when I do my unsupported
    Lejog at some point in the distant future, as I was planning to camp 'wild' (probably a misleading
    term in Britain) to save on the money and time.

    I suppose they only come into their own if you've a gps thingy you want to leave on and won't be
    able to recharge. For me, charging the phone would be a brilliant excuse for spending a couple of
    hours in the pub! On the one hand you've saved me about £30, on the other you've cost me ££££ :)

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  5. Simon Proven

    Simon Proven Guest

    [email protected] (Julian) wrote in message news:<[email protected]>...

    > The only trouble is that no-one seems to produce a really suitable charging cable to allow me to
    > use my leg power to charge my gadgets. There is a "Pedal and Power" thing available at
    > http://www.ikonglobal.com/readme.htm but this includes lots of unnecessary bits that I don't want
    > - all I need is a cable, socket and power management.
    >
    > I believe that in Holland Mobile Phone companies are providing free units for anyone taking out a
    > phone contract.

    > Does anyone know anything about these or any other sensible solutions that do not involve
    > soldering irons and electronics degrees?

    My Pedal & Power's just arrived in the post today (well, arrived whilst I was in France & handed to
    me by my neighbour this morning as I left for work). I too have a Schmidt. I will try wiring it up
    to my existing set-up, all I need is a 3-way switch to select between driving the lights and driving
    the charger. I'll report back once I've got some experience of it, probably a few weeks at least. I
    too wish to charge GPS etc. The mobile phone's fine for a week or so between charges (less if used a
    lot or when the signal's poor). However if I have more than one thing I wish to charge (eg PDA, GPS
    etc) then using car chargers for them will save on effort.

    On the subject of producing a circuit yourself, it's not really very easy without a soldering iron.
    An electronics degree isn't necessary though. Example step-up and rectification circuits are
    available on the web. Indeed, National Semi now have a web site that allows you to enter your design
    requirements and it will produce you a circuit design.

    Simon
     
  6. MartinM

    MartinM Guest

    "Arthur Clune" <[email protected]> wrote in message news:<[email protected]>...
    > Julian <[email protected]> wrote:
    > : Has anyone come across a straightforward solution to this rather modern cycling problem?
    >
    > It's a standand gizmo that gets re-invented every few years, along with direct drive and
    > regenerative braking, and fails for the same reasons they do.
    >
    > Your Schmit will produce 3W. 6W if you get the new one. The latter might be useful to charge
    > something small, but you'll have to step the voltage to whatever the thing wants, losing power,
    > and indeed, your step will have to deal with lots of different voltages AC v DC and all the
    > rest (more waste of power). And the real problem is that humans don't have that much power to
    > start with.
    >
    > My mobile lasts a week on a charge and charges in 2-3 hours. Surely once a week you'll find a
    > campsite/pub/cage that will let you charge a mobile?

    This takes me back; was it the 1970's _Survivors_ series where the diehards from The Old World had
    rigged up 8 or so dynamoes to a turbo trainer + bike to run their Music Centre (that was a
    turntable/cassette/tuner for the not so old) ?
     
  7. Julian wrote:

    > Has anyone come across a straightforward solution to this rather modern cycling problem?
    >
    > When I go cycle touring I could simply stay out of touch, not take any pictures, use pieces of
    > paper and get lost but the fact is that I want my mobile, my digital camera, my Palm and possibly
    > a GPS with me when I go away. All of these have rather short useful lives in the absence of a
    > method of recharging them. I could of course stay in hotels or hire a car to get access to
    > electricity but why?
    >
    > Of course I have managed in the past without any of this and had many happy cycling tours, but you
    > just do get used to having certain stuff around and requirements change.
    >
    > I do have a Schmidt hub which produces leg powered electricity for very little effort and I read
    > that most of these electronic gadgets can be charged to a reasonable extent in about half an hours
    > cycling.
    >
    > The only trouble is that no-one seems to produce a really suitable charging cable to allow me to
    > use my leg power to charge my gadgets. There is a "Pedal and Power" thing available at
    > http://www.ikonglobal.com/readme.htm but this includes lots of unnecessary bits that I don't want
    > - all I need is a cable, socket and power management.
    >
    > I believe that in Holland Mobile Phone companies are providing free units for anyone taking out a
    > phone contract.
    >
    > Does anyone know anything about these or any other sensible solutions that do not involve
    > soldering irons and electronics degrees?

    I did the calculations and the 6V B&M dynamo couldn't produce enough power to charge my mobile, and
    that was before allowing for transformer losses.
     
  8. M-Gineering

    M-Gineering Guest

    MartinM wrote:
    >
    > "Arthur Clune" <[email protected]> wrote in message news:<[email protected]>...
    > > Julian <[email protected]> wrote:
    > > : Has anyone come across a straightforward solution to this rather modern cycling problem?
    > >
    > > It's a standand gizmo that gets re-invented every few years, along with direct drive and
    > > regenerative braking, and fails for the same reasons they do.
    > >
    > > Your Schmit will produce 3W. 6W if you get the new one. The latter might be useful to charge
    > > something small, but you'll have to step the voltage to whatever the thing wants, losing power,
    > > and indeed, your step will have to deal with lots of different voltages AC v DC and all the
    > > rest (more waste of power). And the real problem is that humans don't have that much power to
    > > start with.
    > >
    > > My mobile lasts a week on a charge and charges in 2-3 hours. Surely once a week you'll find a
    > > campsite/pub/cage that will let you charge a mobile?
    >
    > This takes me back; was it the 1970's _Survivors_ series where the diehards from The Old World had
    > rigged up 8 or so dynamoes to a turbo trainer + bike to run their Music Centre (that was a
    > turntable/cassette/tuner for the not so old) ?

    You only need one SON for that, rigged as a roller dynamo ;) 220V is easy, if you are in
    shape that is!

    --
    ---
    Marten Gerritsen

    INFOapestaartjeM-GINEERINGpuntNL www.m-gineering.nl
     
  9. On Tue, 02 Mar 2004 04:58:05 -0800, Julian wrote:

    > Has anyone come across a straightforward solution to this rather modern cycling problem?

    > Does anyone know anything about these or any other sensible solutions that do not involve
    > soldering irons and electronics degrees?

    You could build this circuit using only plugblock (the plastic stuff with screw-terminals) but it
    would be very inefficient and only supply .2A or so - possibly enough to charge some appliances. You
    could improve it some by using a 'bridge rectifier' that uses 4 diodes instead of the single diode
    shown here - in which case you could probably draw 0.4A. Realistically, I would learn to solder to
    avoid loose connections.

    Dynamo AC Rectifier diode ------------------->|------------------- +xV regulated
    | |
    Zener diode ~ | ^ _ big electrolytic capacitor (rated at 2X Volts)
    | _
    | |
    Dynamo AC | | ---------------------------------------- 0V

    This circuit works by converting the AC dynamo output to DC using a single-diode rectifier. You'd
    need a few 100 microfarad electrolytic capacitor to smooth voltage fluctuations. The zener diode
    only starts conducting when the voltage accross the capacitor exceeds its rated voltage. It only
    gives moderately good voltage regulation, and if your appliance doesn't use too much power, the
    zener diode will get quite hot. If it were a 6V zener diode, you would probably want to choose at
    least a 12W component, two 3V 6W components, about 10 ordinary silicon rectifier diodes... The power
    consumption would be about equal to that of an ordinary lightbulb. The electronics parts would cost
    about a pound from Maplins - and a tiny plastic box to put them in would cost you about £5.

    Incidentally, if your appliances are drawing any reasonable amount of current this circuit will
    be more efficient than the obvious alternative that uses a rectifier & 3-terminal voltage
    regulator. At suboptimal currents, dynamos can produce very high voltages - you may theoretically
    end up using 0.25A at 60V (15 watts) rather than 0.5A at 6V (3W) - that amounts to a fair degree
    of extra pedalling. I haven't tested thoroughly, but at no load I get surprisingly high voltages
    from my Schmidt.

    The commercial versions probably use something called a 'switching regulator' to achieve the best
    possible efficiency.

    Please everyone point out the intentional mistakes,

    AC
     
  10. On Wed, 03 Mar 2004 00:08:44 +0000, anonymous coward wrote:

    > On Tue, 02 Mar 2004 04:58:05 -0800, Julian wrote:
    >
    >> Has anyone come across a straightforward solution to this rather modern cycling problem?
    >
    >> Does anyone know anything about these or any other sensible solutions that do not involve
    >> soldering irons and electronics degrees?

    I just thought of a potentially easier solution than the one that I just proposed that may or may
    not work...

    If your appliances come with the sort of 'switch mode' charger that works at either 110 or 230V you
    may be able to plug it straight into your Schmidt dynamo without any additional circuitry
    whatsoever. Just wire the dynamo output to the live and neutral wires of a 3-terminal socket.

    Provided your dynamo light's not on, your dynamo will produce a pretty high voltage AC. Old-style
    chargers that have transformers inside are sensitive to both voltage and the frequency of the AC
    power - they will not work and may overheat. New style ones are much less fussy and may well work.

    At your own risk...

    Maplins also sell some solar powered battery chargers that aren't too expensive.

    AC

    >
    > You could build this circuit using only plugblock (the plastic stuff with screw-terminals) but it
    > would be very inefficient and only supply .2A or so - possibly enough to charge some appliances.
    > You could improve it some by using a 'bridge rectifier' that uses 4 diodes instead of the single
    > diode shown here - in which case you could probably draw 0.4A. Realistically, I would learn to
    > solder to avoid loose connections.
    >
    > Dynamo AC Rectifier diode ------------------->|------------------- +xV regulated
    > | |
    > Zener diode ~ | ^ _ big electrolytic capacitor (rated at 2X Volts)
    > | _
    > | |
    > Dynamo AC | | ---------------------------------------- 0V
    >
    > This circuit works by converting the AC dynamo output to DC using a single-diode rectifier. You'd
    > need a few 100 microfarad electrolytic capacitor to smooth voltage fluctuations. The zener diode
    > only starts conducting when the voltage accross the capacitor exceeds its rated voltage. It only
    > gives moderately good voltage regulation, and if your appliance doesn't use too much power, the
    > zener diode will get quite hot. If it were a 6V zener diode, you would probably want to choose at
    > least a 12W component, two 3V 6W components, about 10 ordinary silicon rectifier diodes... The
    > power consumption would be about equal to that of an ordinary lightbulb. The electronics parts
    > would cost about a pound from Maplins - and a tiny plastic box to put them in would cost you
    > about £5.
    >
    > Incidentally, if your appliances are drawing any reasonable amount of current this circuit will be
    > more efficient than the obvious alternative that uses a rectifier & 3-terminal voltage regulator.
    > At suboptimal currents, dynamos can produce very high voltages - you may theoretically end up
    > using 0.25A at 60V (15 watts) rather than 0.5A at 6V (3W) - that amounts to a fair degree of extra
    > pedalling. I haven't tested thoroughly, but at no load I get surprisingly high voltages from my
    > Schmidt.
    >
    > The commercial versions probably use something called a 'switching regulator' to achieve the best
    > possible efficiency.
    >
    > Please everyone point out the intentional mistakes,
    >
    > AC
     
  11. On Tue, 02 Mar 2004 04:58:05 -0800, Julian wrote:

    > Has anyone come across a straightforward solution to this rather modern cycling problem?

    > Does anyone know anything about these or any other sensible solutions that do not involve
    > soldering irons and electronics degrees?

    You could build this circuit using only plugblock (plastic strips of screw-terminals) but it would
    be very inefficient and only supply 0.2 amps or so - possibly enough to charge some appliances. You
    could improve it by using a 'bridge rectifier' that uses 4 diodes instead of the single diode shown
    here - in which case you could probably draw .4A. Realistically if you want to build something like
    this you should probably learn to solder it in order to avoid loose connections.

    Dynamo AC Rectifier diode ------------------->|------------------- +xV regulated
    | |
    Zener diode ~ | ^ _ big capacitor (rated at 2X Volts)
    | _
    | |
    Dynamo AC | | ---------------------------------------- 0V

    This circuit works by converting the AC dynamo output to DC using a single-diode rectifier then
    using a zener diode to regulate the voltage. You'd need a >100 microfarad electrolytic capacitor to
    smooth voltage fluctuations - be sure of connecting it the right way round (the negative lead should
    be marked with a - sign). The zener diode only starts conducting when the rectified voltage exceeds
    its 'breakdown voltage'. This stops the voltage across the capacitor exceeding the desired voltage
    but if your appliance doesn't use a lot of power the zener diode will get quite hot. If you wanted
    to use a 6V zener diode, you would probably want to choose at least a 12W component, or you could
    use two 3V 6W components in series, or about 10 ordinary silicon rectifier diodes... The power
    consumption would be similar to that of an ordinary dynamo lightbulb. The electronics parts would
    cost about a pound from Maplins - and a tiny plastic box to put them in would cost you about £5.

    Incidentally, if your appliances are drawing any reasonable amount of current this circuit will be
    more efficient than the 'textbook' alternative that uses a rectifier & 3-terminal voltage
    regulator. Dynamos try to source a constant current, and at currents less than the design current
    they can produce very high voltages - for the sake of argument you may theoretically cause yours to
    supply 0.25A at 60V (15 watts) rather than 0.5A at 6V (3W) - amounting to a fair degree of extra
    pedalling restance. I haven't tested thoroughly, but at no load I get surprisingly high voltages
    from my Schmidt.

    The commercial versions probably use something called a 'switching regulator' to achieve the best
    possible efficiency - it would take some experience to build one of these.

    Please everyone point out the intentional mistakes, drawbacks I haven't thought of.

    AC
     
  12. Paul

    Paul Guest

    Anonymous Coward wrote: - " Maplins also sell some solar powered battery chargers that aren't too
    expensive."

    This is my suggstions too. Have a look at
    http://shop.teknek.com/catalog/product_info.php?cPath=23&products_id=29

    You could probably fasten it to your back or the back of the bike and charge it as you go. Should be
    light and more simple than using the dynamo.

    I should add that I don't have one though.

    Cheers

    Paul
     
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