Dynamo on a Uni for GPS/PPC power

Has anyone ever tried a dynamo on a Uni?

I've just got a PocketPC with built-in GPS. Battery life is around 2 or
3 hours which is pretty hopeless if I want a constant fix & a track. The
set-up I'm thinking of is a 'Pedal & Power charger'
(http://www.ikonglobal.com/index.html) so I could make a cup of tea, run
a mini fridge or even keep the GPS charged.

Apart from the bulk of the dynamo (2 inches or so projection from the
sidewall), lack of speed, the frame-fixing issues and the water damage
from landing in puddles/rivers, can anyone see any major drawbacks?

Thanks
Mike


--
mikepenton - sometimes level
------------------------------------------------------------------------
mikepenton's Profile: http://www.unicyclist.com/profile/7090
View this thread: http://www.unicyclist.com/thread/37957

get a better gps unit. there are some that have much longer battery
life. and it might not work so well for uni but i've seen touring bikers
with photovoltaics on the topp of their gear to charge stuff.


--
markf - movie nerd

stuck in iowa and unemployed.
------------------------------------------------------------------------
markf's Profile: http://www.unicyclist.com/profile/8102
View this thread: http://www.unicyclist.com/thread/37957

I use the Garmin E-trex, it is a little backpacking GPS but it can show
agerage speed, top speed, current speed and what not, its really little
too.



you can get them for about 60 bucks


--
total uni - my avatar is big too!

Trials is the devil - jack huges
------------------------------------------------------------------------
total uni's Profile: http://www.unicyclist.com/profile/8125
View this thread: http://www.unicyclist.com/thread/37957

A 'better' gps unit is not a sensible option. As I already have vector &
rasterized mapping on the PPC there is no point wasting money on a
second unit which duplicates the same tasks or offers much less. I know
that I could have had a basic non-mapping GPS with a longer battery life
and a seperate PPC for less money.
Hence the option of the dynamo.


--
mikepenton - sometimes level
------------------------------------------------------------------------
mikepenton's Profile: http://www.unicyclist.com/profile/7090
View this thread: http://www.unicyclist.com/thread/37957

What type of batteries are you using? Try using NiMH with a high mah
rating. Those last a ton longer than alkaline and are rechargeable.


--
Seager - that one guy who does that stuff

'Team RoadShow' (http://www.teamroadshow.com)
------------------------------------------------------------------------
Seager's Profile: http://www.unicyclist.com/profile/8840
View this thread: http://www.unicyclist.com/thread/37957

mikepenton wrote:
*... can anyone see any major drawbacks?
*


Going through the electrical engineering pain of building such a unit.
You can't just inject the power of the dynamo into the ppc. You need a
regulating device with capacity in between. I don't know if such a thing
exists on the market.

Wogri


--
wogri - That *** looks ***

http://www.wogri.at
http://unicycling.wogri.at
------------------------------------------------------------------------
wogri's Profile: http://www.unicyclist.com/profile/7490
View this thread: http://www.unicyclist.com/thread/37957

hmmm ... any of you guys seen the 'charging unit' part of that kit
posted available for sale ...?

Cuz, I still have a generator that I've had since I was a kid that still
works.
I believe it supplies the same volts/amp as the one in the kit.

Thx in advance.


--
DigitalDave - scabless

'nf7-s ~ xp2400mobile'
(http://www.anandtech.com/mysystemrig.html?rigid=21988)
'20,124 3dm01' (http://service.futuremark.com/compare?2k1=8399731)

my will to live was stronger than my will to die. - iggy pop
that which does not kill me, makes me stronger. - friedrich nietzsche
1899

------------------------------------------------------------------------
DigitalDave's Profile: http://www.unicyclist.com/profile/8003
View this thread: http://www.unicyclist.com/thread/37957

I'd be concerned about how well it can charge the battery. It probably
doesn't give a constant charge to the battery which could be bad for the
rechargeable batteries. It might lower the useful life of the
batteries. Could it end up over-charging the batteries?

Will the PPC be able to run off the external power? Will the Pedal
Power thing give a consistent enough source of power so the PPC can run
off the external power? Can the PPC switch from external power to
battery power on the fly (for example when you stop pedaling)?

What happens if you run the Pedal Power backwards during an idle?

I'd also be concerned about the durability of the PPC. Those things
aren't made to take rough or outdoor treatment.

The thing would probably be better suited for a 29er or a Coker on the
roads (asphalt).


--
john_childs - Guinness Mojo

john_childs (att) hotmail (dott) com
Gallery: '' (http://www.unicyclist.com/gallery/john_childs)
------------------------------------------------------------------------
john_childs's Profile: http://www.unicyclist.com/profile/449
View this thread: http://www.unicyclist.com/thread/37957

john_childs wrote:
*
What happens if you run the Pedal Power backwards during an idle? *


It's AC current ... so doesn't matter.

I'm assuming it's got a capacitor to hold a converted DC charge.


--
DigitalDave - scabless

'nf7-s ~ xp2400mobile'
(http://www.anandtech.com/mysystemrig.html?rigid=21988)
'20,124 3dm01' (http://service.futuremark.com/compare?2k1=8399731)

my will to live was stronger than my will to die. - iggy pop
that which does not kill me, makes me stronger. - friedrich nietzsche
1899

------------------------------------------------------------------------
DigitalDave's Profile: http://www.unicyclist.com/profile/8003
View this thread: http://www.unicyclist.com/thread/37957

"Seager" writes:

What type of batteries are you using? Try using NiMH with a high mah
rating. Those last a ton longer than alkaline and are rechargeable.

Not so. High capacity alkaline AA cells have more charge (2850 mAh)
than high capacity NiMH AA cells (2300 mAh). Not only that, but some
equipment (especially high current equipment like my Nikon Coolpix
800) can't cope with the lower voltage (1.2V vs. 1.5V) of nickel
chemistry batteries.

Rather than dragging the wheel with a generator, I'd look into hooking
up a rechargeable (gel-cell or external NiMH pack) battery to the
computer/GPS.

Ken