Charging appliances using dynamo

Quoted message said:

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
ikonglobal.comreadme.htmOpen ↗ 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 <[email hidden]> 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 clune.orgclune.orgOpen ↗ "Technolibertarians make a philosophy out of a personality defect"
- Paulina Borsook

Quoted message said:

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

Quoted message said:

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
ikonglobal.comreadme.htmOpen ↗ 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.

Quoted message said:

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" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Julian <[email hidden]> 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 said:

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
ikonglobal.comreadme.htmOpen ↗ 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 said:

"Arthur Clune" <[email hidden]> wrote in message news:<[email hidden]>...

Quoted message said:

Julian <[email hidden]> 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

Julian said:

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

Quoted message said:

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

anonymous coward said:

Julian said:

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

Quoted message said:

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

Quoted message said:

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

Julian said:

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

Quoted message said:

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

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
shop.teknek.comproduct info.phpOpen ↗

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