Triple Luxeon Star Bike Light

Here is a project I'm presently working on. Tell me what you think of it?

I just put together a bike light for someone, using three 1 watt Luxeon Stars. I put them into a StarLux head. I'm not using the body, but am putting the tailcap into the back of the head and sealing it water tight. This will bolt to the handlebars using aluminum brackets to sink the heat to the handlebars. It uses a 12 volt power supply. Light should be be 8 to 10 watts. It draws about 1.2 amps (10V under load X 1.2amps). Two of them would be nearly 20 watts.

I also put some strontium aluminate into the inside of the head, so it glows brightly after the light is shut off. Provides emergency lighting for 20 minutes, even if there is no power at all. Can be used for roadside emergencies if power fails. Glows for another 12 hours.

Wayne
www.elektrolumens.com

I'll say that it would be something I'd love to have. It could also double as a handlebar warmer in the wintertime. Do you have any pictures?

James

Hey Wayne. As you know, I have your first Triple Luxeon Star bike light:



The battery pack is infact 12 volts, but when the 3 LS are on, a test of each LS shows just barely over 3 volts. Now, the heat sink that I have is obviously massive. I wonder if 15 volts would work better, or some other form of power. I hooked up another 3 volt pack to the 12 volt pack, and the Luxeons were noticably brighter, while still under 4 volts draw.

Orion, I think you would be better off with a different source of power. AA alkalines are not good for high current drain projects like 3 LS's hooked together. Nimh's are pretty good, but you have to match the voltages they have to the LS's which can be tricky.

Electrolumens, pictures please!! And how about a chart of how long the LS's will last when they're overdriven that hard? What kind of power source? I like the handwarmer idea for those cold rides.

Originally posted by LightBright:
Orion, I think you would be better off with a different source of power. AA alkalines are not good for high current drain projects like 3 LS's hooked together. Nimh's are pretty good, but you have to match the voltages they have to the LS's which can be tricky.

Electrolumens, pictures please!! And how about a chart of how long the LS's will last when they're overdriven that hard? What kind of power source? I like the handwarmer idea for those cold rides.

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<font size="2" face="Verdana, Arial">
Lightbright,

I'll put some pics up later tonight.

As far as LED longevity, the main thing to consider is keeping the emitter from overheating, which causes light emission degredation


Orion,

When driving the emitters in series, the voltage is divided between the emitters, but not the current. So if you measure the current, like at 900mA or 1000mA, that is being delivered to each emitter. You need to measure the current to really know what is going on.

Wayne J.

how do you like the light? does it perform well for you?

Bob

"Orion,

When driving the emitters in series, the voltage is divided between the emitters, but not the current. So if you measure the current, like at 900mA or 1000mA, that is being delivered to each emitter. You need to measure the current to really know what is going on."

The current will be the same through each component in a series circuit.
The voltage will not be divided evenly amongst the components, but will depend on the drop across each component.

I'm certainly no expert but I have been riding my bike to work in the dark for years with various light configurations and I have some experience with 1W white Luxeons (I'm assuming yours are white) so here's my take:

I classify bike headlights into two simple categories. (1) Lights that enable the rider to SEE the road/trail in the dark and (2) lights that enable the rider to BE SEEN by others.

Lights in the second category are fine under limited conditions e.g. use under bright street lights and/or a full moon and use at very low speeds.

Lights in the first category must be much more powerful. The faster you go, the brighter they must be. A long throw and wide beam (I know they are somewhat mutually exclusive) are essential.

On long rides on city streets I usually mount a light of each type on my bike (or helmet). In brightly lit areas I use only the less powerful light to save power.

Your 3x1w Luxeon light will certainly draw the attention of motorists. You will be seen. If anything it may be a little overkill in that department.

I would not, however, use this light to illuminate the road except at very low speeds. I simply do not believe that 1W Luxeons with or without optics have enough throw to light up what I consider to be a sufficient amount of the road in front of me.

Hi Wayne have you tried 3 -5watts in this situation and do you think a 5 watter could run on 12 volts. 12 volts would provide higher Ma does'nt it?

I think without special optics none
of the available LED lights are good
bike lights. There must be a beam pattern
which lights the road well and do not blind
others. There are bike lights with only 2.4W
that are illuminating the road better than
a 10W MR11 e.g.

Cheers Ralf

Originally posted by RickLux:
Hi Wayne have you tried 3 -5watts in this situation and do you think a 5 watter could run on 12 volts. 12 volts would provide higher Ma does'nt it?

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<font size="2" face="Verdana, Arial">12 volts for a 5 watt LS is super overkill.. it will push the current to well over 2 amps. That's urm... 3 x 10< watts = Super hot = super heatsinking needed....

Ralf,
Yes-I agree with you. We make special optics including a 10 degree x 20 degree elliptical lens for Lumileds Star LEDs. In addition to the elliptical lens, we also offer a 6 degree, 30 degree and 45 degree beam pattern lenses.

Originally posted by Darkaway:
[qb]I'm certainly no expert but I have been riding my bike to work in the dark for years with various light configurations and I have some experience with 1W white Luxeons (I'm assuming yours are white) so here's my take:

qb]

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<font size="2" face="Verdana, Arial">I always appreciate feedback from bike riders, as I do not ride much at night. If I do, I go pretty slow, so I do not need a lot of light.

You would have to see how bright the 3 Luxeon Stars are in series. Pretty bright! Much brighter than a single.

I would say that I would like to find a good solution to using the Luxeon star for a bike light.

The newer optics I have have a much more intense and centered beam. I'm anxious to see how they work with the white 5W. Using a 5W cyan, and the Lumileds optics, I measure around 2,000 lux from 1 meter. Using the new 30mm optics, I measure 3,840 lux, using the same emitter and batteries (not perfectly fresh batteries). This should say something. Is it enough to ride at night at high speeds? Probably not? But two or three 5W might be? I don't know, but I hope to find out.

Perhaps someone might be willing to do road tests?

Wayne J.

Originally posted by ElektroLumens:

Perhaps someone might be willing to do road tests?

Wayne J.

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<font size="2" face="Verdana, Arial">Uhh, that would be me Though I expect to be building my own. I just saw your announcement about making the 30mm optics available, and I plan to buy them as soon as they are available. I have some buck converter circuit boards for running the 5W LS devices, and I am part of the 5W group buy.

My current riding requirements are usually met with a single 5W MR-11 halogen lamp. I expect that a single 5W LS will provide most of the light that I need most of the time.

My plan is to use 3 of the 5W units, normally operated at reduced power, for my general light, and to pump them up to full (or overdriven) when I need increased lighting. I usually only need increased lighting when it is raining or snowing, so heat won't be a problem.

-Jon

Originally posted by BrilliantSolutions:
Ralf,
Yes-I agree with you. We make special optics including a 10 degree x 20 degree elliptical lens for Lumileds Star LEDs. In addition to the elliptical lens, we also offer a 6 degree, 30 degree and 45 degree beam pattern lenses.

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<font size="2" face="Verdana, Arial">Hi there. I see that you are from Fraen. Welcome! Your company has been noted in these forums in the past! Do you have a way in which us normal LED jockies can buy your standard components?

-Jon

Regarding oncoming traffic, the LS is going to be super bright to them. I am wondering about some sort of hood over the top of the light, to keep oncoming traffic from having to look directly at the emitters. Not sure if it would completely do the job, but perhaps partially. No need for the light to shine up, at oncoming traffic. Just an idea?

Wayne