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  #181  
Old March 17th 17, 08:09 PM posted to rec.bicycles.tech
Joerg[_2_]
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Posts: 3,510
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On 2017-03-16 15:07, Jeff Liebermann wrote:
On Thu, 16 Mar 2017 10:20:43 -0700, Joerg
wrote:

There is no need for 27.5W but there is for 8-10W. That should be
reasonably possible, else the dynamo would have smoked out during their
testing.


If all you're powering are head and tail lights, 10 watts should be
sufficient. However, if you're powering other devices (GPS,
smartphone, rear view camera, electric shifter, fog horn, etc), then
more power is better.


I also have to power an MP3 player. No smart phone since I won't likely
buy one until they can function as good as a GPS devise even while off-grid.

Still, 10W suffices because I can ratchet down or turn off the light on
many trails and MUP. It's mostly needed on roads which I try to avoid
where I can.


http://www.ebay.com/itm/122373782338
(Yet another project that I'll never finish).

That is a neat little instrument.

Yep. I don't have one yet, but it's a real temptation to install one
on all my various unmetered power supplies and battery packs. However,
there's a catch. The common ground is positive (+), not negative.
You can see that in the schematic:
https://img.alicdn.com/imgextra/i3/121163002/TB2NoBogpXXXXahXpXXXXXXXXXX_!!121163002.jpg
where the + leads of both the "DC in" and the load are connected
together. The only ways I could make it work in a negative ground
system was either an isolated power source, isolated load, separate
isolated power supply to run the meter, or a DC-DC inverter.


That would be a show stopper in most applications. Got to have high-side
current sensing.


Impediment, not show stopper. What most users have done after turning
the + wire into an impromptu fuse, is to install a small isolated DC
to DC inverter. The problem is that the current measuring part of the
circuit needs to have some source of power to run the devices used. If
one part of that power source happens to be grounded to either the +
or - input of the voltage measuring part, it won't work. So, the
vendor recommends either floating the input or output grounds, using
independent volt and amp meters, or using an isolated power supply to
power the conglomerated meter. I know that one can get such DC to DC
inverters quite cheaply, but I haven't bothered to search for them.
I'll post something if I find one as I think it might be useful for
your battery pack and dynamo.


Digikey has lots of those. But when such extra measures are needed this
all gets old. Why can't they do high-side sensing? It ain't rocket science.


From a dynamo it's still feasible after things have
been turned to DC because the hub versions usually have two ground-free
terminals. Bottle dynamos unfortunately not. However, when doing MPPT
there already is a micro controller which can then also perform the job
of energy metering.


Yep. I've setup some cheap MPPT solar charge controllers (from eBay).
The better one's have extensive monitoring capabilities, usually on an
LCD or OLED display. If you're counting and budgeting coulombs, it's
a good way to do it.

I would not need that though, maybe just an
indicator of whether the dynamo is able to feed enough for a given light
setting.


Easy enough. The power output of the dynamo is directly proportional
to the RPM and unaffected by the load.



No really. Keep in mind the various losses.


... The load might change
radically, but the dynamo will only deliver XX watts at XX RPM. You
could just measure the RPM, build a lookup table in some kind of
NVRAM, and display the output power.


All I need is a sensitive voltmeter. That tells me whether my battery
juice is being consumed or juice is being added. I have seen waterproof
LED meters with two digits after the decimal point for less than $5.
This is what I am going to add some day. It will also let me see the
charge state before heading out on either bike.


Or, you could get fancy, measure the load voltage and current, and
calculate the power needed to run the lights or whatever. Then
compare the input power available, with the average output power
needed. If there's not enough input power available, you need to shed
some load, or pedal harder.


Nah, too fancy :-)


Even that is expendable if you have a voltmeter riding along
with the Li-Ion battery. In my case I'd just have to make sure it won't
get close to 7V where the electronics will eventually shut things off.


If you do go over, you might want to shed the load slowly or you might
lurch forward as pedaling suddenly becomes easier.


With a 10-15W load?


Nothing beats trying it on the bench, using a variable speed drill or
similar. I haven't observed a sharp knee effect on any of them so far.
Which probably explains the large number of bulbs I blew out in the 80's
when I had to get somewhere fast.


Yeah, I should do that. However, as I previously mumbled, I'm
overloaded, busy, lazy, and uninspired right now.


Same here. The MTB still needs to be fixed, taxes to be done, then there
is work, and right now I am busy with a much higher priority. I brewed a
Belgian Tripel this morning and this afternoon a Superior Strong Ale is
in the process.

--
Regards, Joerg

http://www.analogconsultants.com/
Ads
  #182  
Old March 17th 17, 08:53 PM posted to rec.bicycles.tech
SMS
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Posts: 7,780
Default More About Lights

On 3/17/2017 12:58 PM, Joerg wrote:
On 2017-03-17 12:11, sms wrote:
On 3/13/2017 12:28 PM, Joerg wrote:

snip

You could stick in a Murata LXDC55FAAA-203
http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf
instead of the zener and do a USB version also with only three parts.
But I know that you love designing your own switchers.


$3.50? Mon Dieu! :-)


I got some of the Murata LXDC55FAAA-203 units from Digikey for use at
work. I guess I didn't realize from the picture on the data sheet just
how tiny these things are. Maybe I'll buy some more and try building
some dynamo to USB adapters.


Be carful with that 16V abs max input limit. When the load current drops
this can easily be exceeded by a dynamo, big time. You could burn off
the excess with a zener diode or TVS (though _not_ MOV) but these have
large tolerances and could burn out if not well heat sinked.

I think you need somthing automotive here, some circuit that can stomach
50V or more.


I'd just stick a 15V 5W zener in there for the rare times that the
dynamo is exceeding 11VAC. If I were going to sell these I'd do
something more robust.


  #183  
Old March 17th 17, 08:59 PM posted to rec.bicycles.tech
SMS
external usenet poster
 
Posts: 7,780
Default More About Lights

On 3/17/2017 1:09 PM, Joerg wrote:
On 2017-03-16 15:07, Jeff Liebermann wrote:
On Thu, 16 Mar 2017 10:20:43 -0700, Joerg
wrote:

There is no need for 27.5W but there is for 8-10W. That should be
reasonably possible, else the dynamo would have smoked out during their
testing.


If all you're powering are head and tail lights, 10 watts should be
sufficient. However, if you're powering other devices (GPS,
smartphone, rear view camera, electric shifter, fog horn, etc), then
more power is better.


I also have to power an MP3 player. No smart phone since I won't likely
buy one until they can function as good as a GPS devise even while
off-grid.


We're already there. Lots of off-grid GPS/mapping apps. No need to use
data or have a data connection. Topos available too. Not free.

Is it as good as a dedicated GPS? Not really because the internal GPS
antenna on a phone is inferior, but for outdoors a phone is good enough.

You really need to get with the program and buy yourself an iPhone 7+,
and iPad Pro with LTE data, a Macbook, a Mac Pro, an Apple watch, and an
Apple TV. Wait a few months and drive down to Cupertino and buy
everything at the new Apple store.
  #184  
Old March 18th 17, 12:00 AM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 3,510
Default More About Lights

On 2017-03-17 13:53, sms wrote:
On 3/17/2017 12:58 PM, Joerg wrote:
On 2017-03-17 12:11, sms wrote:
On 3/13/2017 12:28 PM, Joerg wrote:

snip

You could stick in a Murata LXDC55FAAA-203
http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf
instead of the zener and do a USB version also with only three parts.
But I know that you love designing your own switchers.


$3.50? Mon Dieu! :-)

I got some of the Murata LXDC55FAAA-203 units from Digikey for use at
work. I guess I didn't realize from the picture on the data sheet just
how tiny these things are. Maybe I'll buy some more and try building
some dynamo to USB adapters.


Be carful with that 16V abs max input limit. When the load current drops
this can easily be exceeded by a dynamo, big time. You could burn off
the excess with a zener diode or TVS (though _not_ MOV) but these have
large tolerances and could burn out if not well heat sinked.

I think you need somthing automotive here, some circuit that can stomach
50V or more.


I'd just stick a 15V 5W zener in there for the rare times that the
dynamo is exceeding 11VAC. If I were going to sell these I'd do
something more robust.


And then you have to cool that zener. And hand-pick one because of
tolerance. Also, those things are soft. Better to build an "active
zener" with a TL431 and a transistor. However, I'd prefer a switch mode
regulator that can handle north of 50V because then you can capture all
the juice generated on that long downhill section. I have a few of those
when riding into towns west of here. On the way back, of course, it's
sweating and suppressed cussing because those 1000+ feet have to be
gained back.

--
Regards, Joerg

http://www.analogconsultants.com/
  #185  
Old March 18th 17, 12:03 AM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 3,510
Default More About Lights

On 2017-03-17 13:59, sms wrote:
On 3/17/2017 1:09 PM, Joerg wrote:
On 2017-03-16 15:07, Jeff Liebermann wrote:
On Thu, 16 Mar 2017 10:20:43 -0700, Joerg
wrote:

There is no need for 27.5W but there is for 8-10W. That should be
reasonably possible, else the dynamo would have smoked out during their
testing.

If all you're powering are head and tail lights, 10 watts should be
sufficient. However, if you're powering other devices (GPS,
smartphone, rear view camera, electric shifter, fog horn, etc), then
more power is better.


I also have to power an MP3 player. No smart phone since I won't likely
buy one until they can function as good as a GPS devise even while
off-grid.


We're already there. Lots of off-grid GPS/mapping apps. No need to use
data or have a data connection. Topos available too. Not free.


If it's reasonably priced it is ok. However, every time I asked dirt
bikers who venture out into the sticks in Nevada they said that they
tried their smart phones but that it really doesn't work well without a
Garmin or other native GPS device.


Is it as good as a dedicated GPS? Not really because the internal GPS
antenna on a phone is inferior, but for outdoors a phone is good enough.


It is quite mountainous out here and that might be the problem.


You really need to get with the program and buy yourself an iPhone 7+,
and iPad Pro with LTE data, a Macbook, a Mac Pro, an Apple watch, and an
Apple TV. Wait a few months and drive down to Cupertino and buy
everything at the new Apple store.



Only over my dead body :-)

--
Regards, Joerg

http://www.analogconsultants.com/
  #186  
Old March 18th 17, 01:59 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 4,584
Default More About Lights

On 3/17/2017 8:00 PM, Joerg wrote:
On 2017-03-17 13:53, sms wrote:
On 3/17/2017 12:58 PM, Joerg wrote:
On 2017-03-17 12:11, sms wrote:
On 3/13/2017 12:28 PM, Joerg wrote:

snip

You could stick in a Murata LXDC55FAAA-203
http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf
instead of the zener and do a USB version also with only three parts.
But I know that you love designing your own switchers.


$3.50? Mon Dieu! :-)

I got some of the Murata LXDC55FAAA-203 units from Digikey for use at
work. I guess I didn't realize from the picture on the data sheet just
how tiny these things are. Maybe I'll buy some more and try building
some dynamo to USB adapters.


Be carful with that 16V abs max input limit. When the load current drops
this can easily be exceeded by a dynamo, big time. You could burn off
the excess with a zener diode or TVS (though _not_ MOV) but these have
large tolerances and could burn out if not well heat sinked.

I think you need somthing automotive here, some circuit that can stomach
50V or more.


I'd just stick a 15V 5W zener in there for the rare times that the
dynamo is exceeding 11VAC. If I were going to sell these I'd do
something more robust.


And then you have to cool that zener. And hand-pick one because of
tolerance. Also, those things are soft. Better to build an "active
zener" with a TL431 and a transistor. However, I'd prefer a switch mode
regulator that can handle north of 50V because then you can capture all
the juice generated on that long downhill section. I have a few of those
when riding into towns west of here. On the way back, of course, it's
sweating and suppressed cussing because those 1000+ feet have to be
gained back.


If you're trying to charge USB devices, you should at least look at this
design:

http://fahrradzukunft.de/12/minimal-lader/

It seems to be much simpler than what you're considering.


--
- Frank Krygowski
  #187  
Old March 18th 17, 02:55 AM posted to rec.bicycles.tech
JBeattie
external usenet poster
 
Posts: 2,346
Default More About Lights

On Friday, March 17, 2017 at 7:00:01 PM UTC-7, Frank Krygowski wrote:
On 3/17/2017 8:00 PM, Joerg wrote:
On 2017-03-17 13:53, sms wrote:
On 3/17/2017 12:58 PM, Joerg wrote:
On 2017-03-17 12:11, sms wrote:
On 3/13/2017 12:28 PM, Joerg wrote:

snip

You could stick in a Murata LXDC55FAAA-203
http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf
instead of the zener and do a USB version also with only three parts.
But I know that you love designing your own switchers.


$3.50? Mon Dieu! :-)

I got some of the Murata LXDC55FAAA-203 units from Digikey for use at
work. I guess I didn't realize from the picture on the data sheet just
how tiny these things are. Maybe I'll buy some more and try building
some dynamo to USB adapters.


Be carful with that 16V abs max input limit. When the load current drops
this can easily be exceeded by a dynamo, big time. You could burn off
the excess with a zener diode or TVS (though _not_ MOV) but these have
large tolerances and could burn out if not well heat sinked.

I think you need somthing automotive here, some circuit that can stomach
50V or more.

I'd just stick a 15V 5W zener in there for the rare times that the
dynamo is exceeding 11VAC. If I were going to sell these I'd do
something more robust.


And then you have to cool that zener. And hand-pick one because of
tolerance. Also, those things are soft. Better to build an "active
zener" with a TL431 and a transistor. However, I'd prefer a switch mode
regulator that can handle north of 50V because then you can capture all
the juice generated on that long downhill section. I have a few of those
when riding into towns west of here. On the way back, of course, it's
sweating and suppressed cussing because those 1000+ feet have to be
gained back.


If you're trying to charge USB devices, you should at least look at this
design:

http://fahrradzukunft.de/12/minimal-lader/

It seems to be much simpler than what you're considering.


I use this device: http://images.wisegeek.com/standard-us-power-outlet.jpg

-- Jay Beattie.
  #188  
Old March 18th 17, 03:50 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
external usenet poster
 
Posts: 4,584
Default More About Lights

On 3/17/2017 10:55 PM, jbeattie wrote:
On Friday, March 17, 2017 at 7:00:01 PM UTC-7, Frank Krygowski wrote:
On 3/17/2017 8:00 PM, Joerg wrote:
On 2017-03-17 13:53, sms wrote:
On 3/17/2017 12:58 PM, Joerg wrote:
On 2017-03-17 12:11, sms wrote:
On 3/13/2017 12:28 PM, Joerg wrote:

snip

You could stick in a Murata LXDC55FAAA-203
http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf
instead of the zener and do a USB version also with only three parts.
But I know that you love designing your own switchers.


$3.50? Mon Dieu! :-)

I got some of the Murata LXDC55FAAA-203 units from Digikey for use at
work. I guess I didn't realize from the picture on the data sheet just
how tiny these things are. Maybe I'll buy some more and try building
some dynamo to USB adapters.


Be carful with that 16V abs max input limit. When the load current drops
this can easily be exceeded by a dynamo, big time. You could burn off
the excess with a zener diode or TVS (though _not_ MOV) but these have
large tolerances and could burn out if not well heat sinked.

I think you need somthing automotive here, some circuit that can stomach
50V or more.

I'd just stick a 15V 5W zener in there for the rare times that the
dynamo is exceeding 11VAC. If I were going to sell these I'd do
something more robust.


And then you have to cool that zener. And hand-pick one because of
tolerance. Also, those things are soft. Better to build an "active
zener" with a TL431 and a transistor. However, I'd prefer a switch mode
regulator that can handle north of 50V because then you can capture all
the juice generated on that long downhill section. I have a few of those
when riding into towns west of here. On the way back, of course, it's
sweating and suppressed cussing because those 1000+ feet have to be
gained back.


If you're trying to charge USB devices, you should at least look at this
design:

http://fahrradzukunft.de/12/minimal-lader/

It seems to be much simpler than what you're considering.


I use this device: http://images.wisegeek.com/standard-us-power-outlet.jpg


It's not very portable.



--
- Frank Krygowski
  #189  
Old March 18th 17, 03:05 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 3,510
Default More About Lights

On 2017-03-17 20:50, Frank Krygowski wrote:
On 3/17/2017 10:55 PM, jbeattie wrote:
On Friday, March 17, 2017 at 7:00:01 PM UTC-7, Frank Krygowski wrote:
On 3/17/2017 8:00 PM, Joerg wrote:
On 2017-03-17 13:53, sms wrote:
On 3/17/2017 12:58 PM, Joerg wrote:
On 2017-03-17 12:11, sms wrote:
On 3/13/2017 12:28 PM, Joerg wrote:

snip

You could stick in a Murata LXDC55FAAA-203
http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf

instead of the zener and do a USB version also with only three
parts.
But I know that you love designing your own switchers.


$3.50? Mon Dieu! :-)

I got some of the Murata LXDC55FAAA-203 units from Digikey for
use at
work. I guess I didn't realize from the picture on the data sheet
just
how tiny these things are. Maybe I'll buy some more and try building
some dynamo to USB adapters.


Be carful with that 16V abs max input limit. When the load current
drops
this can easily be exceeded by a dynamo, big time. You could burn off
the excess with a zener diode or TVS (though _not_ MOV) but these
have
large tolerances and could burn out if not well heat sinked.

I think you need somthing automotive here, some circuit that can
stomach
50V or more.

I'd just stick a 15V 5W zener in there for the rare times that the
dynamo is exceeding 11VAC. If I were going to sell these I'd do
something more robust.


And then you have to cool that zener. And hand-pick one because of
tolerance. Also, those things are soft. Better to build an "active
zener" with a TL431 and a transistor. However, I'd prefer a switch mode
regulator that can handle north of 50V because then you can capture all
the juice generated on that long downhill section. I have a few of
those
when riding into towns west of here. On the way back, of course, it's
sweating and suppressed cussing because those 1000+ feet have to be
gained back.

If you're trying to charge USB devices, you should at least look at this
design:

http://fahrradzukunft.de/12/minimal-lader/

It seems to be much simpler than what you're considering.



A zener diode is not a suitable device to limit USB voltage. The upper
limit in the standard is 5.25V.

https://en.wikipedia.org/wiki/USB

He should have at least a TL431 with a transistor as a shunt in there.

Anyhow, that is not why I'd invest in a hub dynamo some day. I want it
to be able to supply my 8.2V power bus on the road bike and charge its
Li-Ion battery pack. The MTB has the same but that will unlikely ever
get a hub dynamo. The smart thing is to at least have poor man's MPPT
and for USB provide a decent secondary regulator, preferably switch-mode
as well.


I use this device:
http://images.wisegeek.com/standard-us-power-outlet.jpg


It's not very portable.


I had some on my road bike a couple of weeks ago. Along with other
electrical gear I bought for a rework session.

--
Regards, Joerg

http://www.analogconsultants.com/
  #190  
Old March 18th 17, 06:00 PM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 2,339
Default More About Lights

On Fri, 17 Mar 2017 17:03:19 -0700, Joerg
wrote:

However, every time I asked dirt
bikers who venture out into the sticks in Nevada they said that they
tried their smart phones but that it really doesn't work well without a
Garmin or other native GPS device.


I've had the same experience when I try to run the GPS in "airplane
mode". The GPS uses location data from the cell sites (AGPS) to
improve its E911 accuracy and shorten acquisition time. Turn off the
cellular part of the phone, or try to use GPS in an area where there
are no cell sites is a problem.

"Using an Android GPS in Airplane Mode"
http://backcountrynavigator.com/using-android-gps-airplane-mode/

There are also issues with the antenna. Size matters and the bigger
patch antennas used in handheld GPS receivers offers much better
sensitivity and view of the sky.

I have a collection of about 10 assorted GPS receivers. Occasionally,
I do a comparison of performance in challenging areas (hills,
mountains, trees, indoors, underground garages, highly reflective
environments, RF polluted environments, etc). If I have a nearby cell
site to use as a starting or reference point, my Moto G smartphone
does quite well. My Samsung S6, not so well but good enough. However,
if I go into "airplane mode" to save battery power, performance sucks.
The main problem is that without the position sanity check provided by
AGPS, the smartphone GPS will produce wildly erratic positions caused
by reflections, often miles away from my actual location. Some of the
handheld mapping GPS receivers do the same thing, but not as badly.

There is also some mapping trickery involved when using maps and AGPS.
In order to improve (or fake) accuracy for E911, mapping smartphone
apps like to round off positions to coincide with a roadway. It's a
fair assumption that someone using a GPS map program would be on some
kind of road. That's great, until you ride off the road and your GPS
tracker thinks you're still on the roadway. So far, it hasn't been a
problem.

You really need to get with the program and buy yourself an iPhone 7+,


Only over my dead body :-)


I'll resist the temptation to say something clever about your
destructive testing methods.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 




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