Anyone use bike generator lights anymore?

SMS

Twitchell wrote:

> For $300, you'd think a little more effort would have gone into putting it into
> anything but a plain, plastic box. It might be the best light in the world but
> sheesh, comon'...being ugly is not a good selling point.

It's aluminum, not plastic. Those high power LEDs generate a tremendous
amount of waste heat, so almost every high power LED lamp will use
aluminum cases that act as a heat sink.

SMS

Twitchell wrote:

> For $300, you'd think a little more effort would have gone into putting it into
> anything but a plain, plastic box. It might be the best light in the world but
> sheesh, comon'...being ugly is not a good selling point.

It's aluminum, not plastic. Those high power LEDs generate a tremendous
amount of waste heat, so almost every high power LED lamp will use
aluminum cases that act as a heat sink.

SMS

A Muzi wrote:
> Ablang wrote:
>> No one seems to be talking about it, and I can't even find a good
>> place online to order them from.
>>
>> Does anyone have a site for that stuff, or is it being phased out?
>
> http://www.yellowjersey.org/dynamos.html

Andrew, not sure if you're aware of this but
"http://www.yellowjersey.org/sanyo_dynohub.html" is a dead link.

SMS

A Muzi wrote:
> Ablang wrote:
>> No one seems to be talking about it, and I can't even find a good
>> place online to order them from.
>>
>> Does anyone have a site for that stuff, or is it being phased out?
>
> http://www.yellowjersey.org/dynamos.html

Andrew, not sure if you're aware of this but
"http://www.yellowjersey.org/sanyo_dynohub.html" is a dead link.

SMS

Doug McLaren wrote:
> On 2008-06-27, Doug McLaren <dougmc+usenet@frenzied.us> wrote:
>
> | For example, I've got a Cateye HL-EL 500 which they rate at 1000
> | candlepower, they say it lasts 30 hours. It's quite bright. Assuming
> | that the 4 AA batteries are 2500 mAh (good alkalines), that's an
> | average of around 1/10th of a watt.
>
> I screwed up the math -- forgot that there's four AA's, not one. So
> it's about one half a watt, and probably goes down from there. I
> guess I should just measure it. Either way, it's pretty bright,
> though it certainly can't compare to the 15 watt halogen jobs I've
> seen.
>
> Good point that Mark made about the dynamo putting out AC -- but even
> with a 20% loss from a bridge rectifier and voltage regulator (perhaps
> one of the fairly efficient DC to DC converters?), it ought to be a
> big win if your new LED light is 3x as efficient as your old halogen
> light.

The maximum efficiency of a bridge rectifier is 81.2%. A buck-boost
switching regulator will be about 80% efficient. So you're down to about
65%. So my previous post was incorrect, it's not wasting 20%, it's
wasting 35%. Then you run into the problem that while the LED is more
efficient, it's more difficult to direct all the light to illuminate the
road, so for all the expense of the electronics to drive the LED you
haven't gained much over a simple incandescent bulb.

SMS

Doug McLaren wrote:
> On 2008-06-27, Doug McLaren <dougmc+usenet@frenzied.us> wrote:
>
> | For example, I've got a Cateye HL-EL 500 which they rate at 1000
> | candlepower, they say it lasts 30 hours. It's quite bright. Assuming
> | that the 4 AA batteries are 2500 mAh (good alkalines), that's an
> | average of around 1/10th of a watt.
>
> I screwed up the math -- forgot that there's four AA's, not one. So
> it's about one half a watt, and probably goes down from there. I
> guess I should just measure it. Either way, it's pretty bright,
> though it certainly can't compare to the 15 watt halogen jobs I've
> seen.
>
> Good point that Mark made about the dynamo putting out AC -- but even
> with a 20% loss from a bridge rectifier and voltage regulator (perhaps
> one of the fairly efficient DC to DC converters?), it ought to be a
> big win if your new LED light is 3x as efficient as your old halogen
> light.

The maximum efficiency of a bridge rectifier is 81.2%. A buck-boost
switching regulator will be about 80% efficient. So you're down to about
65%. So my previous post was incorrect, it's not wasting 20%, it's
wasting 35%. Then you run into the problem that while the LED is more
efficient, it's more difficult to direct all the light to illuminate the
road, so for all the expense of the electronics to drive the LED you
haven't gained much over a simple incandescent bulb.

SMS

Tim McNamara wrote:

> Lots of other folks- Clive and Frank, just to name two- have told you
> that these simple systems work just fine. You're the one convinced that
> something approaching klieg lights are essential for commuting, and
> you're flat wrong. You've been told many times but you refuse to accept
> plain fact because it contradicts your beliefs.

I prefer to believe the experts, since it jives with my own experience.

Type "expert dynamos" into the Google search bar, and click on "I'm
Feeling Lucky." I've collected the views of many lighting experts, both
individuals and organizatons, on that page.

Here's some of them:

Bicycle Federation of Wisconsin
(http://www.bfw.org/new_bfw/articles...?printable=true)
"Generators One of the oldest lighting systems is the generator. This
type of lighting works off a generator (or dynamo) that is powered when
it makes contact with the bicycle's tire. A generator system is often
set up to power a headlight and a taillight. These systems are reliable,
but often lack the power to really light up the road. Generators are
more popular in Europe than in the United States."

Ken Kifer (http://www.kenkifer.com/bikepages/commute/accessor.htm)
I have been using generator lights for many years, and I find them very
suitable for riding in the country at night and on touring trips. There
are no batteries to fade or go bad, and the light gets brighter while
going downhill. The beam is very wide and thus visible from all sides.
On the other hand, a generator light is not very bright in city traffic
and goes out each time you stop at a red light.

Peter Cole
"I'm always surprised that so many serious cyclists who otherwise
recognize the equivalence of bicycles to other vehicles take exception
to lighting requirements. I wouldn't dare operate a motorcycle with a 3W
light, so I don't understand the recommendation to operate a bicycle (at
often similar speeds ) with such inadequate lights. Perhaps this was an
accommodation to the technological limitations of the past, but in these
times of readily available and relatively cheap, high-wattage
alternatives, it seems a bad way to go."

Michael Press

In article <qxe9k.83138$312.37009@newsfe12.ams2>,
Peter Pan <peter.pan@invalid.mail.kom> wrote:

> Tim McNamara wrote:
> >> In article <LVa9k.6878$cW3.5801@nlpi064.nbdc.sbc.com>,
> >> SMS <scharf.steven@geemail.com> wrote:
>
> > Bullshit, Steven, you've had dozens of replies in previous threads
> > pointing out errors on your Web page. The problem is that you are
> > incapable of accepting that your notions about dynamo lighting systems
> > are incorrect.
>
> Yet people still see fit in stroking his ego by replying to his hot
> turds posted here.

People unfamiliar with rbt and unfamiliar with SMS
ask questions in rbt about bicycle lighting. It is
no good allowing his misrepresentations to remain
unchallenged.

SMS prefers crude responses with no technical
content; such as yours for instance.

Anybody know if Peter Pan is SMS's sock puppet?

--
Michael Press

A Muzi

>> SMS:
>>> There are only a couple of LED dynamo powered headlights greater
>>> than 1 watt.

> Andreas Oehler <andreas.oehler@gmx.de> wrote:
>> You seem not up-to-date. I know no dynamo-LED-headlamp which consumes
>> only 1 Watt - besides the one made by Spaninga. All others B&M
>> DLumotec, IQ FLy, Basta Steady, Inoled 10+, 20+, Extreme, Schmidt
>> Edelux, Supernova and a lot of far eastern ones take from 2.4 to 4
>> Watt.

>> SMS:
>>> The problem with dynamos is that they're ill-suited to powering
>>> LEDs. They put out AC power at widely varying voltage,

> Andreas Oehler <andreas.oehler@gmx.de> wrote:
>> Voltage is of ne relevance here. All classic dynamos are *better*
>> suited to power LEDs than batteries, because they are by principle
>> current-limited. Just connect a bridge rectifier and one (or more in
>> series) LED and you are done.

>> SMS:
>>> and the
>>> electronics to rectify and regulate the output wastes at least 20%
>>> of the available power.

> Andreas Oehler <andreas.oehler@gmx.de> wrote:
>> You are talking of LED-battery-lights here? There you need some ways
>> to limit the current. A lot of battery lights (like Cateye EL300,
>> EL500) use just a resistor for this purpose. Very inefficient indeed.

>> SMS:
>>> The best LED headlight for dynamos is the Solidlight 1203D/1203DR,
>>> see "http://www.solidlights.co.uk/products/1203d.php".

> Andreas Oehler <andreas.oehler@gmx.de> wrote:
>> You are joking again. The 1203D uses oldfashioned inefficient LEDs
>> and inappropriate rotationaö-symmetric optics.

>> SMS:
>>> It has two 3 watt LEDs, so when you're moving at higher speed you
>>> can have more light if the dynamo is putting out sufficient power.
>>> It costs £150.00, or just about $300.

> Andreas Oehler <andreas.oehler@gmx.de> wrote:
>> An B&M IQ Fly is available for less than 60 Euro, consumes 3-4 Watt,
>> is brighter than the 1203D and gives an efficient beam to illuminate
>> the road ahead.

Tim McNamara wrote:
> Thanks for the perspective, Andreas. You do, after all, know much more
> about dynamo lighting than SMS does. It's too bad that he will not
> accept your (or anyone else's) repeated corrections of his
> misconceptions. In fact he even managed to claim in this thread that no
> one has corrected the errors on his Web page! (Of course, since it's
> *his* Web page he's the only one who can correct it, but he has at least
> been given the information needed to correct the most egregious of his
> errors about optics and dynamo lighting systems. Stubbornness prevents
> him from owning up, unfortunately).

> Perhaps SMS should Google you to verify your expertise.

Good idea! AltaVista says 'steven scharff light'= 24,300 results.
'adreas oehler light' = 16,400 results
'frank krygowski light' = 1,820 results
'tim macnamara light' = 44,100 results
'andrew muzi light' = 22,100 results
'carl fogel light' = 112,000 results
'peter white light' = 67 MILLION results

(looks like Frank wins!)

Some reader may draw meaning from that. I can't.
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
** Posted from http://www.teranews.com **

Peter Pan

Michael Press wrote:
> People unfamiliar with rbt and unfamiliar with SMS
> ask questions in rbt about bicycle lighting. It is
> no good allowing his misrepresentations to remain
> unchallenged.

And it then rolls into another 5K thread "yes..no..yes...I am right..no
You're not".... which puts off people altogether, and encourages 'mr
lighting expert' to continue posting.

> SMS prefers crude responses with no technical
> content; such as yours for instance.
>
> Anybody know if Peter Pan is SMS's sock puppet?

Try finding out for yourself.

A Muzi

SMS wrote:
> A Muzi wrote:
>> Ablang wrote:
>>> No one seems to be talking about it, and I can't even find a good
>>> place online to order them from.
>>>
>>> Does anyone have a site for that stuff, or is it being phased out?
>>
>> http://www.yellowjersey.org/dynamos.html
>
> Andrew, not sure if you're aware of this but
> "http://www.yellowjersey.org/sanyo_dynohub.html" is a dead link.
Whoops sorry and thank you.

Those are discontinued; the Shimano units work better an cost less.

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
** Posted from http://www.teranews.com **

Twitchell

In article <u4u9k.11667$jI5.9642@flpi148.ffdc.sbc.com>, SMS says...
>
>Twitchell wrote:
>
>>For $300, you'd think a little more effort would have gone into putting it into
>>anything but a plain, plastic box. It might be the best light in the world but
>> sheesh, comon'...being ugly is not a good selling point.
>
>It's aluminum, not plastic. Those high power LEDs generate a tremendous
>amount of waste heat, so almost every high power LED lamp will use
>aluminum cases that act as a heat sink.

I don't believe LEDs give off heat...they're diodes not incandescent lights.

twitch

Clive George

"Twitchell" <Twitchell_member@newsguy.com> wrote in message
news:g4618l01a9d@drn.newsguy.com...
> In article <u4u9k.11667$jI5.9642@flpi148.ffdc.sbc.com>, SMS says...
>>
>>Twitchell wrote:
>>
>>>For $300, you'd think a little more effort would have gone into putting
>>>it into
>>>anything but a plain, plastic box. It might be the best light in the
>>>world but
>>> sheesh, comon'...being ugly is not a good selling point.
>>
>>It's aluminum, not plastic. Those high power LEDs generate a tremendous
>>amount of waste heat, so almost every high power LED lamp will use
>>aluminum cases that act as a heat sink.
>
> I don't believe LEDs give off heat...they're diodes not incandescent
> lights.

Hmmm.

They are more efficient at giving out light than incandescent bulbs, however
the conversion still isn't that efficient, and the rest comes out as heat.
On a high power LED, that's quite a lot to dissipate.

clive

SMS

Twitchell wrote:

> I don't believe LEDs give off heat...they're diodes not incandescent lights.

LOL, reminds me of when Frank was into his "white hot filament" schtick.

You can learn about the challenges of thermal management of LEDs at
"http://www.lumileds.com/technology/thermal.cfm"

Basically, the higher junction temperature you can tolerate, the greater
the light output, but the more difficult it is to manage the heat. It's
a very small junction, so dissipating that much power requires very
creative heat sinking.

Feel how hot the body of a 3W Cree LED or Luxeon LED flashlight gets
after a few minutes. These will always have metal bodies that act as
heat sinks, so the barrel gets quite warm.