Battery/lighting philosophy for fully-loaded touring?

[Tim McNamara]

In article <[email protected]>,
SMS <[email protected]> wrote:

> _ wrote:
> > On Sat, 14 Apr 2007 19:32:10 -0700, SMS wrote:
> >
> >> Michael Press wrote:
> >>> In article <[email protected]>,
> >>> <[email protected]> wrote:
> >>>
> >>>> Personally, I use a Schmidt hub dynamo for touring.
> >>>>
> >>>> It's bright enough for any speed I'm likely to hit on a
> >>>> fully-loaded touring bike, never needs batteries, and also can
> >>>> power a battery charger during daylight hours to keep my cell
> >>>> phone and radio running.
> >>>>
> >>>> Some day soon I may get one of the newer LED lamps for my
> >>>> generator system, one of the ones with a 1-Farad capacitor to
> >>>> keep a fairly bright standlight going at intersections.
> >>> 1 farad capacitor? Where?
> >> "http://www.allelectronics.com/cgi-bin/category/140910/Super.html"
> >>
> >> Perfect for a 1W Luxeon LED as the forward voltage is below 5.5V.
> >> For a 5W you'll need four of them (two series sets in parallel) as
> >> the forward voltage is more than 5.5V (but less than 11V).
> >
> > Um, perfect perhaps, but not for very long.
>
> You would actually want to have a separate low-wattage LED for a
> standlight, and not use the higher wattage LED while not moving. To
> use the regular lamp as a standlight, two AAA NiCad batteries could
> be used (NiMH could also be used, but are less desirable in this
> application).

My Lumotec Oval Plus has a standlight. It's a white LED, I'd guess
around 0.5W, and it's good for several minutes of light when stopped.
It's enough to be seen at intersections and to read a map or cue sheet.
I have no idea what the value of the capacitor is.

 

[[email protected]]

On Apr 15, 5:13 am, Ben C <[email protected]> wrote:
>
>
> I think I could probably see OK with a 3W light in the dark (I use a
> cheap but effective lead-acid system with 12W altogether, but with only
> one of the lights on it's 6W and that's still quite bright).

Of course, it's not just the wattage that matters.

I recall when my best friend bought a 10 watt rechargeable set from a
well-known mail order company. This was many years ago. Good sized
separate battery on a curly power cord, professional looking headlamp
housing, nice mounting - and almost useless. It didn't come close to
the usability of my standard generator light, because the optics were
so terrible. That 10 watts was sprayed all over creation, not
directed onto the road. Optics makes a huge difference.

Another factor, for incandescent (including halogen) bulbs is the
designed bulb life. Two incandescent bulbs of equivalent wattage can
put out very different numbers of lumens (that is, total light
output). In general, bulbs designed for longer life put out less
lumens per watt; bulbs designed for more lumens per watt don't last as
long. Bike headlight bulbs don't accumulate nearly as many hours as,
say, lights used for ornamental track lighting (the MR-11 bulbs at
your hardware store). So dedicated bike bulbs can and should be
designed for relatively short lives, to allow more light output from
the same wattage.

The optics and the bike-specific bulb design are two reasons a three
watt generator lamp does much better than many people think.

Carrying the wattage idea a bit further, it's obvious that the lumen
per watt ratio of LEDs has completely different constraints. There's
lots of intense research in this direction, and there's little doubt
we'll all end up with LED lights someday. But there's a fair amount
of hype, too.

Just the other day, a friend of mine showed me a couple LED
flashlights he bought. He was marveling at the brightness, and
planned to use them for his night commute. He was sure they'd be
wonderful.

For comparison, I brought in the Cateye Micro II halogen light I keep
as a loaner, plus an old 6 watt rechargeable headlight I used to use.
Even the Cateye (2.4 watt, four AA batteries) absolutely blew away his
brightest LED flashlight. And it probably cost 1/3 as much.

Overall, watts are only a small part of the story. More is not
necessarily better. Optics are critical. Mounting position makes a
huge difference too, as others have explained. When people say "You
can't see well enough with just three watts" they're likely comparing
apples and oranges - or maybe watermelons.

- Frank Krygowski

 

[SMS]

Tim McNamara wrote:

> My Lumotec Oval Plus has a standlight. It's a white LED, I'd guess
> around 0.5W, and it's good for several minutes of light when stopped.
> It's enough to be seen at intersections and to read a map or cue sheet.
> I have no idea what the value of the capacitor is.

Those 1F capacitors that I referenced are used in those Faraday
principle flashlights, so I suspect that something very similar is used
in the standlights.

I doubt if the standlight is 0.5W. Probably closer to .05W.

 

[Tim McNamara]

In article <[email protected]>,
SMS <[email protected]> wrote:

> Tim McNamara wrote:
>
> > My Lumotec Oval Plus has a standlight. It's a white LED, I'd guess
> > around 0.5W, and it's good for several minutes of light when
> > stopped. It's enough to be seen at intersections and to read a map
> > or cue sheet. I have no idea what the value of the capacitor is.
>
> Those 1F capacitors that I referenced are used in those Faraday
> principle flashlights, so I suspect that something very similar is
> used in the standlights.
>
> I doubt if the standlight is 0.5W. Probably closer to .05W.

Maybe. It's about as bright as my 0.5W mini LED flashlight, hence my
estimate. But I can't find any specs about the LED.

 

[[email protected]]

On Sun, 15 Apr 2007 04:17:18 -0500, Ben C <[email protected]> wrote:

>On 2007-04-14, Michael Press <[email protected]> wrote:
>> In article <[email protected]>,
>> Tim McNamara <[email protected]> wrote:
>>
>>> It takes about 45 minutes for the retina to become fully dark
>>> adapted, and light interferes with this.
>>
>> Dark adaptation goes in stages. Rhodopsin, metarhodopsin I,
>> metarhodopsin II, retinol, ... are involved in chemical processes
>> for night vision. Rhodopsin is the light sensitive molecule. The
>> cycle requires energy to regenerate the rhodopsin. In low light
>> situations such a twilight, the rhodopsin is regenerated in the
>> retina by ambient light. (Some mammals have a reflective membrane
>> behind the rods to reflect light back through the rods to enhance
>> the regeneration of rhodopsin).
>
>Is that the thing that makes cats' eyes shiny at night? (I mean the ones
>on cats, not the metaphorical ones embedded in the road).

Dear Ben,

Yes, the tapetum lucidum:

http://en.wikipedia.org/wiki/Tapetum_lucidum

Owls and some other birds also have it.

So do many turtles and crocodilians.

Some fish, too.

Basically, light passes through a thin layer containing the rods. If
the light hits a shiny layer beyond that, the light is reflected back
and hits the same rods again.

The rods on the ends of the nerves are so tiny that they don't much
care which way the light hits them--in fact, they point toward the
back of our eyes, away from the pupil.

Cheers,

Carl Fogel

 

[Michael Press]

In article <[email protected]>,
[email protected] wrote:

> On Sun, 15 Apr 2007 04:17:18 -0500, Ben C <[email protected]> wrote:
>
> >On 2007-04-14, Michael Press <[email protected]> wrote:
> >> In article <[email protected]>,
> >> Tim McNamara <[email protected]> wrote:
> >>
> >>> It takes about 45 minutes for the retina to become fully dark
> >>> adapted, and light interferes with this.
> >>
> >> Dark adaptation goes in stages. Rhodopsin, metarhodopsin I,
> >> metarhodopsin II, retinol, ... are involved in chemical processes
> >> for night vision. Rhodopsin is the light sensitive molecule. The
> >> cycle requires energy to regenerate the rhodopsin. In low light
> >> situations such a twilight, the rhodopsin is regenerated in the
> >> retina by ambient light. (Some mammals have a reflective membrane
> >> behind the rods to reflect light back through the rods to enhance
> >> the regeneration of rhodopsin).
> >
> >Is that the thing that makes cats' eyes shiny at night? (I mean the ones
> >on cats, not the metaphorical ones embedded in the road).
>
> Dear Ben,
>
> Yes, the tapetum lucidum:
>
> http://en.wikipedia.org/wiki/Tapetum_lucidum
>
> Owls and some other birds also have it.
>
> So do many turtles and crocodilians.
>
> Some fish, too.
>
> Basically, light passes through a thin layer containing the rods. If
> the light hits a shiny layer beyond that, the light is reflected back
> and hits the same rods again.
>
> The rods on the ends of the nerves are so tiny that they don't much
> care which way the light hits them--in fact, they point toward the
> back of our eyes, away from the pupil.

The reaction

rhodopsin <--> metarhodopsin I
light

is caused by light. The rightward reaction induces a
nerve impulse. The leftward reaction regenerates the
rhodopsin so that it can again precipitate a nerve
impulse. The purpose of the tapetum lucida is to
increase the rate of the leftward reaction, not for
imaging. If the metarhodopsin I molecule does not soon
collect light and change back to rhodopsin, then the
reaction

metarhodopsin I --> opsin + all-trans-retinal + H20

takes place, slowing down the rate of rhodopsin regeneration.

--
Michael Press

 

[Ben C]

On 2007-04-15, [email protected] <[email protected]> wrote:
> On Apr 15, 5:13 am, Ben C <[email protected]> wrote:
>>
>>
>> I think I could probably see OK with a 3W light in the dark (I use a
>> cheap but effective lead-acid system with 12W altogether, but with only
>> one of the lights on it's 6W and that's still quite bright).
>
> Of course, it's not just the wattage that matters.
>
> I recall when my best friend bought a 10 watt rechargeable set from a
> well-known mail order company. This was many years ago. Good sized
> separate battery on a curly power cord, professional looking headlamp
> housing, nice mounting - and almost useless.

That sounds like the lights I have. Not useless, but as you suggest I'm
sure a lower powered light with better optics could certainly be
brighter.

[...]
> Carrying the wattage idea a bit further, it's obvious that the lumen
> per watt ratio of LEDs has completely different constraints. There's
> lots of intense research in this direction, and there's little doubt
> we'll all end up with LED lights someday. But there's a fair amount
> of hype, too.

Perhaps a possibility of laser lights as well, which I think a small
number of cars may have.

 

[Michael Press]

In article <[email protected]>,
Ben C <[email protected]> wrote:

> On 2007-04-14, Tim McNamara <[email protected]> wrote:
> > In article <[email protected]>,
> > Ben C <[email protected]> wrote:
> >
> >> On 2007-04-14, <[email protected]> <[email protected]> wrote:
> >> > In article <[email protected]>,
> >> > [email protected] says...
> >> >> Andrew Price wrote:
> >> >>
> >> >> > Really? What on earth does the amount of load on the bike have
> >> >> > to do with the rider's ability to see with the light provided by
> >> >> > the dynamo?
> >> >>
> >> >> It's not the load, it's where you're likely to be riding on a
> >> >> tour. If you do your tours in urban areas with bright city lights,
> >> >> then you could probably get by with a dynamo. Most people tend to
> >> >> do their touring in more rural settings.
> >> >
> >> > In more rural settings, without the glare of street lights and with
> >> > less oncoming traffic, bright lights are less useful than in the
> >> > city where you need to bring up road details against a bright
> >> > background. I often enjoy riding without lights in rural areas,
> >> > other than a tail light and a minimal front light so I can be seen.
> >>
> >> You must eat a lot of carrots. I have a real problem seeing where I'm
> >> going in those conditions unless it's a full moon.
> >
> [...]
> > The other criticism I have of battery powered lights is physiological.
> > Really bright lights (especially mounted high) result in a lot of light
> > bouncing back from near objects which can reduce dark adaptation of the
> > eye. It takes about 45 minutes for the retina to become fully dark
> > adapted, and light interferes with this.
>
> Where I live you'd be very lucky to go for as long as 45 minutes without
> being dazzled by a car coming the other way.
>
> There is a theory that you can shut one eye when that happens to keep
> that eye dark-adapted. Not sure how effective that is, or what your
> liver would make of the situation re rhodopsin shunting.

It works if you can keep all the light out. How much
gets through the tissue of the eyelid? Mythbusters
tested the myth that sailers wore an eye patch to keep
one eye dark adapted for descending to the lower decks
that were very dim. Their result showed that an eye
kept under a patch remains dark adapted in full sun light.

The full dark adaptation process is forced at the
retina. Build up of all-trans-retinal from the reaction
of rhodopsin with light reacts in the retina to form
all-trans-vitamin A which builds up in the blood stream
and in the liver where we have

all-trans-vitamin A --> II-cis-vitamin A

and the latter is carried back to the eye where it is
further processed and is recombined with optin to form
rhodoptin.

Bright light on the retina quenches this reaction chain
by removing the forcing population of all-trans-retinal.

--
Michael Press

 

[Ben C]

On 2007-04-16, Michael Press <[email protected]> wrote:
> In article <[email protected]>,
> Ben C <[email protected]> wrote:
>
>> On 2007-04-14, Tim McNamara <[email protected]> wrote:
>> > In article <[email protected]>,
>> > Ben C <[email protected]> wrote:
>> >
>> >> On 2007-04-14, <[email protected]> <[email protected]> wrote:
>> >> > In article <[email protected]>,
>> >> > [email protected] says...
>> >> >> Andrew Price wrote:
>> >> >>
>> >> >> > Really? What on earth does the amount of load on the bike have
>> >> >> > to do with the rider's ability to see with the light provided by
>> >> >> > the dynamo?
>> >> >>
>> >> >> It's not the load, it's where you're likely to be riding on a
>> >> >> tour. If you do your tours in urban areas with bright city lights,
>> >> >> then you could probably get by with a dynamo. Most people tend to
>> >> >> do their touring in more rural settings.
>> >> >
>> >> > In more rural settings, without the glare of street lights and with
>> >> > less oncoming traffic, bright lights are less useful than in the
>> >> > city where you need to bring up road details against a bright
>> >> > background. I often enjoy riding without lights in rural areas,
>> >> > other than a tail light and a minimal front light so I can be seen.
>> >>
>> >> You must eat a lot of carrots. I have a real problem seeing where I'm
>> >> going in those conditions unless it's a full moon.
>> >
>> [...]
>> > The other criticism I have of battery powered lights is physiological.
>> > Really bright lights (especially mounted high) result in a lot of light
>> > bouncing back from near objects which can reduce dark adaptation of the
>> > eye. It takes about 45 minutes for the retina to become fully dark
>> > adapted, and light interferes with this.
>>
>> Where I live you'd be very lucky to go for as long as 45 minutes without
>> being dazzled by a car coming the other way.
>>
>> There is a theory that you can shut one eye when that happens to keep
>> that eye dark-adapted. Not sure how effective that is, or what your
>> liver would make of the situation re rhodopsin shunting.
>
> It works if you can keep all the light out. How much
> gets through the tissue of the eyelid? Mythbusters
> tested the myth that sailers wore an eye patch to keep
> one eye dark adapted for descending to the lower decks
> that were very dim. Their result showed that an eye
> kept under a patch remains dark adapted in full sun light.
>
> The full dark adaptation process is forced at the
> retina. Build up of all-trans-retinal from the reaction
> of rhodopsin with light reacts in the retina to form
> all-trans-vitamin A which builds up in the blood stream
> and in the liver where we have
>
> all-trans-vitamin A --> II-cis-vitamin A
>
> and the latter is carried back to the eye where it is
> further processed and is recombined with optin to form
> rhodoptin.

Do you mean opsin and rhodopsin?

I wonder if it also gets carried back to the other eye where it's not
needed.

Anyway, thanks for the explanation.

> Bright light on the retina quenches this reaction chain
> by removing the forcing population of all-trans-retinal.

 

[Michael Press]

In article <[email protected]>,
Ben C <[email protected]> wrote:

> On 2007-04-16, Michael Press <[email protected]> wrote:
> > In article <[email protected]>,
> > Ben C <[email protected]> wrote:
> >
> >> On 2007-04-14, Tim McNamara <[email protected]> wrote:
> >> > In article <[email protected]>,
> >> > Ben C <[email protected]> wrote:
> >> >
> >> >> On 2007-04-14, <[email protected]> <[email protected]> wrote:
> >> >> > In article <[email protected]>,
> >> >> > [email protected] says...
> >> >> >> Andrew Price wrote:
> >> >> >>
> >> >> >> > Really? What on earth does the amount of load on the bike have
> >> >> >> > to do with the rider's ability to see with the light provided by
> >> >> >> > the dynamo?
> >> >> >>
> >> >> >> It's not the load, it's where you're likely to be riding on a
> >> >> >> tour. If you do your tours in urban areas with bright city lights,
> >> >> >> then you could probably get by with a dynamo. Most people tend to
> >> >> >> do their touring in more rural settings.
> >> >> >
> >> >> > In more rural settings, without the glare of street lights and with
> >> >> > less oncoming traffic, bright lights are less useful than in the
> >> >> > city where you need to bring up road details against a bright
> >> >> > background. I often enjoy riding without lights in rural areas,
> >> >> > other than a tail light and a minimal front light so I can be seen.
> >> >>
> >> >> You must eat a lot of carrots. I have a real problem seeing where I'm
> >> >> going in those conditions unless it's a full moon.
> >> >
> >> [...]
> >> > The other criticism I have of battery powered lights is physiological.
> >> > Really bright lights (especially mounted high) result in a lot of light
> >> > bouncing back from near objects which can reduce dark adaptation of the
> >> > eye. It takes about 45 minutes for the retina to become fully dark
> >> > adapted, and light interferes with this.
> >>
> >> Where I live you'd be very lucky to go for as long as 45 minutes without
> >> being dazzled by a car coming the other way.
> >>
> >> There is a theory that you can shut one eye when that happens to keep
> >> that eye dark-adapted. Not sure how effective that is, or what your
> >> liver would make of the situation re rhodopsin shunting.
> >
> > It works if you can keep all the light out. How much
> > gets through the tissue of the eyelid? Mythbusters
> > tested the myth that sailers wore an eye patch to keep
> > one eye dark adapted for descending to the lower decks
> > that were very dim. Their result showed that an eye
> > kept under a patch remains dark adapted in full sun light.
> >
> > The full dark adaptation process is forced at the
> > retina. Build up of all-trans-retinal from the reaction
> > of rhodopsin with light reacts in the retina to form
> > all-trans-vitamin A which builds up in the blood stream
> > and in the liver where we have
> >
> > all-trans-vitamin A --> II-cis-vitamin A
> >
> > and the latter is carried back to the eye where it is
> > further processed and is recombined with optin to form
> > rhodoptin.
>
> Do you mean opsin and rhodopsin?

Yes.

>
> I wonder if it also gets carried back to the other eye where it's not
> needed.

Yes and no. It will infiltrate, as nothing stops it,
but the overall rate is small. The blood concentration
and the concentration in the retina as well as the
reaction in the retina.

II-cis-vitamin A <-> II-cis-retinal

governs the transport rate. The upshot is that in a
retina that is not fully dark adapted, there is little
overall transport of II-cis-vitamin A into the eye. If
neither eye is dark adapted, the build up in the blood
stream means that the reaction in the liver basically
stops.

There are many linked chemical reactions. Removing or
adding one reactant induces rate changes in all of them.
By chemial reaction I also include transport across
membranes.

>
> Anyway, thanks for the explanation.
>
> > Bright light on the retina quenches this reaction chain
> > by removing the forcing population of all-trans-retinal.

--
Michael Press

 

[Sebastian]

Bruce W.1 <[email protected]> wrote:

> I built two lighting systems for my fully-loaded touring bicycle.
>
> I'd like to hear from experienced fully-loaded touring riders on what
> they use and why. Which system would you use? What do you use?

Where do you want to go? What season?

I travelled a lot in northern and central Europe. Most in summertimes.
So why lights? I use to sleep at nights.
Even on a winter tour (christmas/new year) in Denmark (55 North) I had
no use for lightning. 7 hours of daylight were enough.


I use generator lightning as an option. Rarly used on spring and autumn
tours. A Petzl headlight can do the rest to ride a wood trail in new
moon night.

Riding small dark tunnels without lightning is really really dangerous.

rgds.


--
Sebastian Loeck
Frederiksberg Denmark

 

[Dane Buson]

SMS <[email protected]> wrote:
> Michael Press wrote:
>>
>> 1 farad capacitor? Where?
>
> "http://www.allelectronics.com/cgi-bin/category/140910/Super.html"
>
> Perfect for a 1W Luxeon LED as the forward voltage is below 5.5V. For a
> 5W you'll need four of them (two series sets in parallel) as the forward
> voltage is more than 5.5V (but less than 11V).

And thus dies the old electronics lab joke of sending a new student to
the supply closet to ask for a 1 farad capacitor.

/me takes off his hat, has a moment of silence

--
Dane Buson - [email protected]
Who does not love wine, women, and song,
Remains a fool his whole life long.
-- Johann Heinrich Voss

 

[Michael Press]

In article <[email protected]>,
Dane Buson <[email protected]> wrote:

> SMS <[email protected]> wrote:
> > Michael Press wrote:
> >>
> >> 1 farad capacitor? Where?
> >
> > "http://www.allelectronics.com/cgi-bin/category/140910/Super.html"
> >
> > Perfect for a 1W Luxeon LED as the forward voltage is below 5.5V. For a
> > 5W you'll need four of them (two series sets in parallel) as the forward
> > voltage is more than 5.5V (but less than 11V).
>
> And thus dies the old electronics lab joke of sending a new student to
> the supply closet to ask for a 1 farad capacitor.
>
> /me takes off his hat, has a moment of silence

Two of them can be wired up in a 1 inch cube.
At 5.5 v it isn't at death-ray,
but impressive nonetheless.

--
Michael Press

 

[SMS]

Dane Buson wrote:
> SMS <[email protected]> wrote:
>> Michael Press wrote:
>>> 1 farad capacitor? Where?
>> "http://www.allelectronics.com/cgi-bin/category/140910/Super.html"
>>
>> Perfect for a 1W Luxeon LED as the forward voltage is below 5.5V. For a
>> 5W you'll need four of them (two series sets in parallel) as the forward
>> voltage is more than 5.5V (but less than 11V).
>
> And thus dies the old electronics lab joke of sending a new student to
> the supply closet to ask for a 1 farad capacitor.
>
> /me takes off his hat, has a moment of silence

Years ago I remember seeing very large 1 farad capacitors for sale in a
surplus electronics store's catalog, with the tagline "Own Your Own
Farad." They were used in big ECL logic computers.

 

[Jasper Janssen]

On 7 Apr 2007 21:37:17 -0700, "[email protected]"
<[email protected]> wrote:

>As for something forcing you to ride in the dark, bull. You are on a
>loaded tour. If you are camping, you can stop and setup camp
>anywhere. That is the point of carrying camping gear. Or if staying

Now *that* is bull. Camping in random places is mostly illegal, and
definitely inadvisable. Camping is what you do on a camping-ground, not in
a field with a bull in it.


Jasper

 

[Jasper Janssen]

On Sat, 14 Apr 2007 18:06:29 GMT, Michael Press <[email protected]>
wrote:
>In article <[email protected]>,
> <[email protected]> wrote:
>
>> Personally, I use a Schmidt hub dynamo for touring.
>>
>> It's bright enough for any speed I'm likely to hit on a fully-loaded
>> touring bike, never needs batteries, and also can power a battery
>> charger during daylight hours to keep my cell phone and radio running.
>>
>> Some day soon I may get one of the newer LED lamps for my generator
>> system, one of the ones with a 1-Farad capacitor to keep a fairly bright
>> standlight going at intersections.
>
>1 farad capacitor? Where?

All over the fricking place. BIG capacitors, with values from .1 to 10 F
and physical size of a button-cell or so, and very low voltages, are
replacing rechargeable batteries in many places, especially things like
bicycle standlights, keeping clocks/standby circuitry going, etc.

Giggle for "GoldCap".

Jasper

 

[Jasper Janssen]

On Wed, 18 Apr 2007 12:25:13 -0700, Dane Buson <[email protected]> wrote:

>And thus dies the old electronics lab joke of sending a new student to
>the supply closet to ask for a 1 farad capacitor.

I have one or two pots of about 2 inches diameter and 4 in height that are
..1 F, 16V. Ten of them are a Farad. Expensive, though.


Jasper