Charging appliances using dynamo

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
_`\(,_
(_)/ (_)

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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Julian 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

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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(Julian) wrote in message . com...

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

"Arthur Clune" wrote in message ...
Julian 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) ?

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.

MartinM wrote:

"Arthur Clune" wrote in message ...
Julian 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

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
0.2A 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

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/produ...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