SON hub powered GPS
prestonjb
up something cool for my rando bike...
First off what I am doing is a 'fast' tour from Maine to Florida via
Skyline Drive and Blueridge Parkway.
What makes it non-rando is that I'm only doing 115+ miles a day and
I'm not riding any rando stuff. It is rando like in that we are
hoofing it just two guys bikes and gear... no support...
See http://johnandjuliet.com/Maine-2-Florida-2009/ if you want to see
more about that (and perhaps drop by and ride a day or two with me and
Ron...
Well anyway when I biked across the USA probably the only annoying
thing about my bike setup was the GPS. Even with dual AAs for power,
having to carry spares and buying extras every other day was a
hassle. Not to mention expensive.
So because I am into the hub generator stuff I decided to build up a
circuit that will generate 5VDC stable and terminating into a USB
cable.
My testing of the circuit indicates that @8mph the GPS switches over
to generator power. I did a 100 mile fun ride this past weekend and
usually I see the GPS drop at least one bar on the battery
indicator... But this time it stayed at a full charge! No noticeable
decrease in the battery! The GPS is a GPSMAP 76CSx so it does not
contain a charging circuit but now with this generator supply I hope
that I will not need to replace the battery daily/day-and-a-half
intervals.
I designed the circuit using diodes and a zener shunt to convert and
keep the volts under 40vDC and then used a nice little switching
circuit that can take 40VDC in and supply nice and stable 5VDC out.
If I turn on my 3W B&M IQ-CYO(s) then I need to run about 12ish mph to
make the GPS happy. Nice thing is that includes the backlight staying
on full time.
For RANDO riding I will probably run the GPS off of battery at night
and on the generator during the day. I put a nice push button on the
box to turn off the circuit so more power will go to the light(s).
littlecirclesvt.com :: mike beganyi
I'm eyeing the ride and charge for similar function. On a tour when
running a light all the time is not needed swapping sets of AAs
between the charging block (the Ixon IQ) and the GPS every day would
be fine with me...
And I don't have to mess with electronic geekery.
Have a good ride.
Charles Coldwell
beganyi<mike.b...@gmail.com> wrote:
>
> Nice. So it trickle charges the batteries all day long?
It sounds like it doesn't charge the batteries at all. What it does
is prevent discharge of the batteries while the bike is moving.
--
Charles M. Coldwell, W1CMC
"Turn on, log in, tune out"
Somerville, Massachusetts, New England
Mike Beganyi
Charles Coldwell
On Aug 12, 2009, at 7:48 AM, Mike Beganyi wrote:
> Hmmm. Does the power bypass the batteries then? I would assume it
> still flows through the battery... and that the dyno is just
> balancing out the draw from the GPS?
That particular unit (Garmin GPSMAP 76CSx) will run off USB power
when it is available, and off battery power when it is not. His
circuit supplies 5V via a USB connector. There isn't a battery
charging circuit in the GPS unit, however.
You can build the circuit to do this with a single diode ... the 5V
from the USB supply is more than a diode drop higher than the ~3V
from two AA cells.
Chip
--
Charles M. Coldwell, W1CMC
"Turn on, log in, tune out"
Somerville, Massachusetts, New England (FN42kj)
GPG ID: 852E052F
GPG FPR: 77E5 2B51 4907 F08A 7E92 DE80 AFA9 9A8F 852E 052F
li...@jkassen.org
> Well anyway when I biked across the USA probably the only annoying
> thing about my bike setup was the GPS. Even with dual AAs for power,
> having to carry spares and buying extras every other day was a
> hassle. Not to mention expensive.
>
Someone posted a link to the below site on the Bicycle Current List:
http://www.pedalpower.com.au/index_files/Page780.htm
I don't know if this is vaporware or not but it appears someone might be making a product with similar functionality.
Jake
Charles Coldwell
>
>
> Someone posted a link to the below site on the Bicycle Current List:
>
> http://www.pedalpower.com.au/index_files/Page780.htm
>
> I don't know if this is vaporware or not but it appears someone might be making a product with similar functionality.
That is very cool. I wonder which is more useful these days: a 5V
supply with output on a USB connector or a 12V supply with output on
an automotive cigarette lighter connector? Lots of devices have
vehicle adapters, but perhaps as many or more now do USB power.
CRWGPSGUY
On Wed, Aug 12, 2009 at 9:13 AM, <li...@jkassen.org> wrote:
>
>
> Someone posted a link to the below site on the Bicycle Current List:
>
> http://www.pedalpower.com.au/index_files/Page780.htm
>
> I don't know if this is vaporware or not but it appears someone might be
making a product with similar functionality.
> That is very cool. I wonder which is more useful these days...
The thing that is more useful is the thing that works for your devices.
5V usb is often going to have less technical problems then 12V.
>...There isn't a battery charging circuit in the GPS unit, however...
Some do, most don't. They have a solution for that, the V4 device plus the
AC universal Cable. But....
The fine print
...At present we only distribute from Australia... i.e. made of unobtainium.
... waterproof? No, the materials used are water resistant... I could have
guessed this from the connector types they used, a compromise for cost and
universal connection feature.
They seem to be marketing toward non-rando applications. Still if available
it would be easier to modify (water proof, good connectors, good mounting,
etc.) then to build your own.
Paul a NER and Gaget Engineer
TomMarchand
prestonjb
isnt :)
yes my gps doesnt have a charging circuit but it switches to usb or
car power if detected.
charging and swapping batteries is a pain... i did that on another
trip and got concerned i wouldnt find an outlet.... i use to do that
in 24hr racing and only does that stil make sense where i can have a
bank of batteries sitting in a charger that is never more than 5miles
away.. but in 600k rides... and in our winter evening rides trying to
remeber to charge stuff is a hassle...
on pbp i built a batterypack that held 8 aa batts and the gps ran for
60hours (finished in 80hrs... woulda been 70hrs but spent a long time
trying to get my rear wheel fixed.(ended up buying a new one)
as for geekery... it wasnt that difficult... and actjually another way
to do this would be to start with a car usb charger and just add the
ac/dc and shunt... uh ok geekery
btw it can charge other 5v devices... works great w my cell phone (but
i plan to carry a wall wart for the phone... would only use bike to
charge if cant find outlet....
ill try to send pictures soon...
oh the circuit is isolated the gps is also in a plastic mount. so all
grounds are via common wire between units
littlecirclesvt.com :: mike beganyi
trip and got concerned i wouldnt find an outlet...."
http://www.peterwhitecycles.com/b&m.asp
still have to swap batteries... true.
your solution is elegant. wish there were some commercially available.
-mike
PCH Rando
On Aug 13, 6:59 pm, "littlecirclesvt.com :: mike beganyi"
prestonjb
i also get the feeling it may be vaporware :(
Ian Boehm
> well all i can say is no i dont....
>
> i also get the feeling it may be vaporware :(
It isn't vapourware in that Bicycle Victoria (Aust) was able to get one
and write a spiel in the latest edition of its magazine "RideOn".
Recommended retail price for the complete package (hub dynamo, batt.
pack, handlebar mounts etc.) is Au$365. Seems the hub charges a battery
pack which then is used to charge batteries in your toys. Seems a
roundabout way of doing things to me.
RideOn wasn't terribly enthusiastic about some aspects of the device:
- didn't come with Au mains plug [my guess North America 2 pin]
- handlebar mounts flimsy
- setting up confusing
The summary was that it was most useful for multi day tours. Overall
rating of 3 out of 5 for value for money.
With more and more devices using USB connections with +5V for charging
then the time seems ripe for a lightweight, waterproof box with robust
switch mode electronics therein to hook up to ones SON, Shimano etc hub.
--
Cheers
__o
_`\<,
...(*)/(*)
Ian Boehm
Charles Coldwell
>
> Seems the hub charges a battery pack which then is used to charge
> batteries in your toys. Seems a roundabout way of doing things to me.
[ ... ]
> The summary was that it was most useful for multi day tours.
I think these two points are not unrelated. Suppose you want to
charge two 2600 mAH NiMH AA cells (this is what I put in my GPS).
That means you need 5.2 AH at 3V (the charging voltage for NiMH is
about 1.5V per cell even though the output is 1.2V), or 2.6 AH at 6V.
Your hub dynamo is rated for 3W at 6V, so that's 0.5A, therefore it
will take 5.2 hours of cycling to charge your batteries, more or less,
assuming the GPS is off during those 5.2 hours. Now, suppose your GPS
gets about 10 hours of useful life out of your batteries when it is
switched on ... that means they are being discharged at a rate of
about 0.25A, so subtract that from the current coming from the hub
dynamo and you will now take 10.4 hours to recharge the batteries from
dead if the GPS is on while you ride.
In other words, unless you are spending an awful lot of time in the
saddle (as randonneurs and multi day tourists do), this is not a
particularly useful device. In order to make it more useful as a
backup power supply, they added a battery pack.
Charles Coldwell
> Suppose you want to
> charge two 2600 mAH NiMH AA cells (this is what I put in my GPS).
> That means you need 5.2 AH at 3V
Ooops. That should be 2.6 AH at 3V
> (the charging voltage for NiMH is
> about 1.5V per cell even though the output is 1.2V), or 2.6 AH at 6V.
Ooops again. 2.6 AH at 3V.
> Your hub dynamo is rated for 3W at 6V, so that's 0.5A, therefore it
> will take 5.2 hours of cycling to charge your batteries, more or less,
Should be 2.6 hours
> assuming the GPS is off during those 5.2 hours.
2.6 hours again
> Now, suppose your GPS
> gets about 10 hours of useful life out of your batteries when it is
> switched on ... that means they are being discharged at a rate of
> about 0.25A, so subtract that from the current coming from the hub
> dynamo and you will now take 10.4 hours to recharge the batteries from
> dead if the GPS is on while you ride.
should be 5.2 hours.
I think the conclusion is still true ...
> In other words, unless you are spending an awful lot of time in the
> saddle (as randonneurs and multi day tourists do), this is not a
> particularly useful device.
Paul Ries
| I'm reviving a pretty ancient thread here, sorry, but I found the following which apparently about to become a product: http://www.dahon.com/accessories/2010/biologic-reecharge I recently bought a Garmin 705, and am hoping to use it on an upcoming 400k...but it is a pretty steep learning curve! (7 weeks to go) ;-) Any thoughts? Have people made any progress with any other solutions in this area? Thanks -Paul Ries --- On Mon, 8/17/09, Charles Coldwell <cold...@gmail.com> wrote: |
|
Kole Kantner
I have made up some hub charger adapters and they generally work very nicely. Never worrying about charging the Garmin is such a relief for those of us that like to use them. I never could stand the constant attention spent on charging at every stop or trying to keep battery packs connected and fed.
Once the Garmin 705 is fully charged it uses around 80mA to 100mA as long as the backlight isn't too bright. LED lights like my eDelux run pretty much full brightness most of the time, although the Garmin does tend to occasionally gulp a little extra power dimming the light slightly for a few moments. I run my headlight on 24 hours a day for safety so over-voltage protection is not generally a problem. However, without the load from the light, the open circuit voltage spikes of my SON 20R hub pass 30V around 25mph. I have had mixed luck with protective circuits and I can't recommend using any of these devices without the headlight on at all times. We have had several Garmin's get the USB communications function fried with my device and with a similar commercial product from Pedal Power in Australia. I have heard that open circuit spikes can surpass 100V from a hub generator at high speed and that can be very hard to protect against without a load like a headlight to keep the voltages shunted to safe levels.
Using the navigation function of the Garmin 705 is very easy once you get a few poorly documented details sorted out. The default navigation initially appears to be easiest for gpx files used in conjunction with a map sold with some 705s. However, it can be very frustrating to use, with lots of spurious directions from the Garmin and becomes extremely tedious off mapped roads, as for example with bike trails. Coupled with the short battery life, that kept me from using the Garmin more than once or twice in the first year or two I had it. However, after I discovered how to make and use tcx course files and got the charger set up it was like night turned to day. I am a bit embarrassed to say that I now almost never look at a cue sheet after the ride starts. However, I do spend a good bit of time familiarizing myself with it as I create the course. I completed the Sydney Melbourne 1200 earlier this winter without once looking at the cue sheet or other documents besides the brevet card, and most importantly I always knew where I was on the course. I didn't even have an Australian map in the Garmin which didn't cause the slightest problem. Sometimes the route deviated from the planned course, but with common sense navigation it was quite easy to complete the detours and return to the course indicated with the purple line on the Garmin. I usually do carry a cue sheet just in case. Backups for critical items like the cue sheet, lights, and tires are very important, but it is great to save them for emergencies.
Here is how I use the courses function with the Garmin 705:
1) Use .tcx files that you or others create on a site like http://bikeroutetoaster.com, with up to 100 course points specified
2) Name the route in BikeRouteToaster on the Summary tab and download it to a file that always defaults to course.tcx
3) Rename the file to something meaningful so you can distinguish it later, keeping the .tcx extension
4) Copy it to the the Courses folder in the Garmin folder on either the internal or micro SD memory on the Garmin
5) To use the course, press the lower right Menu button and choose Training, Courses, select your course from the list, and Do Course. The name you see here to select will be the one you specified BEFORE downloading it from BikeRouteToaster.
6) When doing a course a new view is available that shows stats on the course including distance to the next turn if you have specified course points in Bike Route Toaster. It also shows the type of course point you specified and which direction to turn. Pushing the joystick up or down gives other options for the lower half of the display including a map with the purple course line on it and your progress on the course with nearby course points displayed.
Of course this is just scratching the surface of the options on the Garmin, but it does provide some key points needed to easily navigate a planned course without the frustration often associated with preparing or using gpx files. I should also say that while BikeRouteToaster can be a fantastic tool, it is also a little rough around the edges and has a habit of locking up periodically or resetting completely, thus losing your work since the last save. It is helpful to save often and when problems come up just reload your saved course from the courses tab and continue from where it stopped working.
I also have slightly mixed feelings on whether using the gps for navigation could be considered "cheating" in some sense, or perhaps more importantly, cheating me of the important challenge of trying to decipher how the cue sheet corresponds to real life road signs or lack there-of. I choose to ride with a gps most of the time and I appreciate the help that tool provides when coupled with my other skills and equipment.
--Kole--
--
WillemJ
presumably ueber reliable.
Willem
> 1) Use .tcx files that you or others create on a site likehttp://bikeroutetoaster.com, with up to 100 course points specified
> > --- On *Mon, 8/17/09, Charles Coldwell /<coldw...@gmail.com>/* wrote:
>
> > From: Charles Coldwell <coldw...@gmail.com>
> > Subject: [Randon] Re: SON hub powered GPS
> > To: "Ian Boehm" <bohem...@melbpc.org.au>
> > Cc: "randon" <ran...@googlegroups.com>
> > Date: Monday, August 17, 2009, 5:38 AM
>
> > On Mon, Aug 17, 2009 at 8:36 AM, Charles
> > Coldwell<coldw...@gmail.com </mc/compose?to=coldw...@gmail.com>>
> > </mc/compose?to=ran...@googlegroups.com>
> > To unsubscribe from this group, send email to
> > randon-un...@googlegroups.com
> > </mc/compose?to=randon-un...@googlegroups.com>