LED headlights?

I've been curious, from following a couple of sort-of related threads.
One guy pointed to a site that had a 1W single LED light (for $35 or so).
Now, 1 watt does not seem like much. At the moment I use a 15W
Nightrider, but am interested in something that would last longer and
still have enough light.

Are there LED lights that really do the job? How many watts would it take?

--

David L. Johnson

__o | This is my religion. There is no need for temples; no need for
_`\(,_ | complicated philosophy. Our own brain, our own heart is our
(_)/ (_) | temple. The philosophy is kindness. --The Dalai Lama

David L. Johnson wrote:

I've been curious, from following a couple of sort-of related threads.
One guy pointed to a site that had a 1W single LED light (for $35 or so).
Now, 1 watt does not seem like much. At the moment I use a 15W
Nightrider, but am interested in something that would last longer and
still have enough light.

Are there LED lights that really do the job? How many watts would it take?

That would be nearly enough light if it's not generating heat; but the LED reputation
for lasting a long time comes from its not drawing much current, which until now
has meant not much light either. So waiting for LEDs to throw out more light so
as to get a longer runtime is doomed to failure from the start, except for some
constant factor from LED efficiency, say two, from not generating heat as well.

Nearly enough light if like you are, like me, satisfied with 3w halogen from two Cateye
HL-1500's, that is.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

"David L. Johnson" writes:

I've been curious, from following a couple of sort-of related
threads. One guy pointed to a site that had a 1W single LED light
(for $35 or so). Now, 1 watt does not seem like much. At the
moment I use a 15W Nightrider, but am interested in something that
would last longer and still have enough light.

Are there LED lights that really do the job?

I don't have direct experience with riding with LED headlights. I
use a Schmidt generator hub and a Lumotec Oval lamp and find that
perfectly adequate for riding all night long.

At PBP this year I saw many people using LED lights, most of which
cast a very bright and very narrow beam. Many people also had *no*
clue about how to mount and aim a headlight, putting it above the bars
and pointing it at the ground right in front of the wheel. The light
appeared adequate in brightness but too narrow in focus for my
tastes.

A to B Magazine did some comparison tests with night photos comparing
beam patterns; you can check their Web site although I don't think the
article itself is posted. You could get it as a back issue.

http://www.atob.org.uk/

There's another Web site with night photos that you can compare
lights.

http://www.fa-technik.adfc.de/Kompon.../vergleich.htm

Peter White's Web site also has some comparisons between lights.

http://www.peterwhitecycles.com/lightingsystems.htm

David L. Johnson wrote:

I've been curious, from following a couple of sort-of related threads.
One guy pointed to a site that had a 1W single LED light (for $35 or so).
Now, 1 watt does not seem like much. At the moment I use a 15W
Nightrider, but am interested in something that would last longer and
still have enough light.

Are there LED lights that really do the job? How many watts would it take?

The Cateye EL-300 passes British Standards for front lights and is
wildly popular over here. Personally I don't think it throws a real
beam, so I'll stick with my dynamo for now.

I would say that for routes you are familiar with, the EL300 is fine,
especially if they are lit at all or if there's moonlight about. It won't
cut it for dark, unfamiliar routes in the dead of night. It does last a long
time on NiMH recharageable AAs. I recharge my batteries after about 15 hours
of use an notice no deteioration of the beam by then. From what I understand
it can go a while longer that that.

I'm waiting for is a good LED light designed to work with dynamos. That
would be cool.

-Bruce-

"Zog The Undeniable" wrote in message
...
David L. Johnson wrote:

I've been curious, from following a couple of sort-of related threads.
One guy pointed to a site that had a 1W single LED light (for $35 or
so).
Now, 1 watt does not seem like much. At the moment I use a 15W
Nightrider, but am interested in something that would last longer and
still have enough light.

Are there LED lights that really do the job? How many watts would it
take?

The Cateye EL-300 passes British Standards for front lights and is
wildly popular over here. Personally I don't think it throws a real
beam, so I'll stick with my dynamo for now.

"David L. Johnson" wrote in message
news
I've been curious, from following a couple of sort-of related threads.
One guy pointed to a site that had a 1W single LED light (for $35 or so).
Now, 1 watt does not seem like much. At the moment I use a 15W
Nightrider, but am interested in something that would last longer and
still have enough light.

Are there LED lights that really do the job? How many watts would it
take?

--

David L. Johnson

I may have been that guy. The light is the Planet Bike Super Spot
(http://www.planetbike.com/feature.html) at ~$35. Performance was selling
it for ~$30 as an intro price. A call to Planet Bike confirmed that they
use the Lumileds Luxeon Star 1W part. They say price is the only thing
keeping them from using the higher output Luxeon Star parts. One of the
frustrating things about the rating of bike lights is that everyone seems to
quote watts as the yardstick. Watts tells you how much power the unit
consumes, it doesn't tell you how much light (in lumens) is output. I
believe that LED lights have higher efficiency as they produce more
lumens/watt than your standard halogen type bulb so using watts isn't a good
unit of comparison. For the future, Lumileds propaganda talks about output
going from about 20 lumens/watt to around 50 lumens/watt in a couple of
years so the future of LED lighting for bicycles might be promising. The
other challenge in LED light design seems to be the optics; standard halogen
reflectors don't seem to be optimal. I currently have a 1W LED flashlight
which is pretty amazing, but I don't believe it has enough light for cycling
at any significant speed. I have one of these Planet Bike units on order,
and plan to modify it using the 3W Luxeon Star if possible ($13 from
www.elekrolumens.com). If it works out, I'll post my findings.

Tim McNamara Said:

At PBP this year I saw many people using LED lights, most of which
cast a very bright and very narrow beam. Many people also had *no*
clue about how to mount and aim a headlight, putting it above the bars
and pointing it at the ground right in front of the wheel. The light

So where is one supposed to put it? As low as possible?

--

QUIPd 1.02: (120 of 679)
- One thing a computer can do that most humans can't is be sealed
- up in a cardboard box and sit in a warehouse. --Jack Handey
##4619 #'Mandrake Linux.'

"David L. Johnson" wrote:

I've been curious, from following a couple of sort-of related threads.
One guy pointed to a site that had a 1W single LED light (for $35 or so).
Now, 1 watt does not seem like much. At the moment I use a 15W
Nightrider, but am interested in something that would last longer and
still have enough light.

Are there LED lights that really do the job? How many watts would it take?

The 1W LED mentioned was almost certainly the Lumileds Luxeon, the
uncontested heavy hitter in LEDs for illumination at this time.
Luxeon LEDs come in 3W and 5W variants as well, though the 5W white
version is extremely short-lived.

http://www.lumileds.com/

The power efficiency of LEDs themselves is not all that impressive;
maybe twice as high as incandescent and improving steadily. There are
other advantages to LED illumination, though. Light color and beam
quality are usually superior to incandescents, and LEDs maintain the
same color output as they diminish in brightness from tired batteries.

Also, since LEDs are rather particular about supply voltage, they are
often paired with voltage-regulating electronics. These electronics
can deliver the side benefit of sucking every available drop of juice
from the batteries, which in effect is the same as delivering higher
power efficiency.

Furthermore, the rated life of most LEDs is on the order of hundreds
of times that of small incandescent bulbs, and they are for practical
purposes shock- and vibration-proof.

With LEDs, colored light is just as efficient to make as white light,
if not more so. This characteristic has already been exploited to
cyclists' benefit by the provision of red blinky lights that can be
left on for days or weeks between battery changes. But red and amber
LEDs could easily be included in an array of mostly white ones, for
the express purpose of selectively lighting up red and amber
reflective markers with a "white" headlight. High intensity true
green, blue, and violet/blacklight LEDs are also available, and some
systems "build" white light by mixing 3 or more pure colors.

The LED Museum has lots of information about LED lighting and
available products:
http://ledmuseum.home.att.net/

Candlepower Forums gives a unique look into the esoteric ways of
flashlight geeks:
http://www.candlepowerforums.com/ubb...at=&Board=UBB3

Chalo Colina

"rosco" wrote:

I have one of these Planet Bike units on order,
and plan to modify it using the 3W Luxeon Star if possible ($13 from
www.elekrolumens.com). If it works out, I'll post my findings.

You'll have to boost the voltage, either by using a higher-voltage
battery string, or by using a step-up DC-DC converter. Lithium ion
rechargeable cells deliver a voltage compatible with direct drive for
most 3W Luxeons.

Chalo Colina

David L. Johnson wrote ...

Are there LED lights that really do the job? How many watts would it
take?

The 3 LED types by Cateye or Smart in flash mode are excellent to allert
cars and other riders - reports back are that they are extraordinarily
attention getting - rather akin to a camera flash attracting attention.

When they are in constant mode the light is softer but more widespread (not
unlike a flourosecent light) than the typical 4x AA cell lights with 2 to 3
w halogen bulb - good enough to use in a bunch on roads where there are ok
street lights.

The great thing about the small LEDs is that they take up no room, have no
cables, 2 x AA batteries last for months (a whole winter for me) and they
can stay on the bars constantly for the occasion you get caught out and feel
the need for a front light (tunnels are an example).

For a dark road of any length, serious wattage is required (10 to 15w) and
current LED's will not enable you to see the things on the road you really
do need to see - but I think the high wattage, high weight solution is a
need for particular routes.

There are also single white LED's in a small plastic case about the size of
10c piece with elastic straps that folk put on the front forks in flash
mode - very little benefit IMHO - but they are great on a key ring and
pretty effectively replace the need for a convenience torch when walking.

I also have the impression that development of LEDs if far from finished.

best, Andrew







--

David L. Johnson

__o | This is my religion. There is no need for temples; no need for
_`\(,_ | complicated philosophy. Our own brain, our own heart is our
(_)/ (_) | temple. The philosophy is kindness. --The Dalai Lama