Kickstarter Light technology
#1
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Kickstarter Light technology
Excuse the cross-post, I stuck this over on the Commute forum as well, but I thought this worth bringing to the attention of the folks here...
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Has anyone seen this https://www.kickstarter.com/projects/...ergy?ref=live?
It looks pretty good - I think I'll jump in on this one...
Lawrence
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Has anyone seen this https://www.kickstarter.com/projects/...ergy?ref=live?
It looks pretty good - I think I'll jump in on this one...
Lawrence
#3
I don't know.
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that seems pretty cool.
I've backed a cool aluminum pen that should ship this month. This might be the second project I back.
I've backed a cool aluminum pen that should ship this month. This might be the second project I back.
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$25 and you get a shirt with your new lights.
- 25 + YOU SELECTED
- The Shirt: Get a personalized high quality functional shirt with the project logo and your name.
- Est. Delivery: Apr 2012
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just by the looks somewhere in 100-150 lumen range.. pretty great idea, but not bright enough for most on here.. If he makes wonder what the price point will be.
#8
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It looks like it could be a viable replacement for hub dynamos as LEDs become brighter. Two 100~150 lumen LEDs already and output looks very good at slower speeds.
#13
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Regardless of whether their idea works well in practice, they clearly state that the dynamo produces drag on the wheel. I think their video even has a title card that says no free lunch. The magnets in the dynamo generate eddy currents in the rim, which create magnetic fields. On commuting, someone mentioned that this effect is very dependent on the distance between the rim and the dynamo, possibly requiring very true wheels.
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They're suggesting the drag on the wheel is less the drag produced by a hub dynamo. In their video they compare (albeit not at all scientifically) their eddy current prototype to an Edelux driven by what I presume is a SON hub. I find it hard to believe that they could pull enough current out of the spinning rim to beat a SON, but then I am no physicist.
The brake light function is nifty, but the change in light output of the front light with braking might be weird/distracting. My own preference would be to have a fixed front mount for their 'kernel' and a cable to mount the light centrally (another criticism mentioned over in the commuting forum).
Perhaps one day they'll offer a stand-alone dynamo kernel that can be used to power third party lights.
The brake light function is nifty, but the change in light output of the front light with braking might be weird/distracting. My own preference would be to have a fixed front mount for their 'kernel' and a cable to mount the light centrally (another criticism mentioned over in the commuting forum).
Perhaps one day they'll offer a stand-alone dynamo kernel that can be used to power third party lights.
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I guess I could get used to having more light when braking instead of less.
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One member has a review in another thread (linked here) but the creator has just announced an update to the Magnic Light which addresses a few issues.
https://www.kickstarter.com/projects/...ess-bicycle-dy
- Stand light
- improved optics
- improved internal circuitry
- options for tail light (quasi-brake light function improved)
- new/improved tooling
https://www.kickstarter.com/projects/...ess-bicycle-dy
- Stand light
- improved optics
- improved internal circuitry
- options for tail light (quasi-brake light function improved)
- new/improved tooling
#20
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I like it. If I owned one I don't know if I would use it as a "stand alone" lamp but if used for back-up ( or in combo with battery lamps ) on extended rides....it could be sweet.
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So, they took a Reelight and added a capacitor.
They are certainly NOT the "first compact contactless bicycle dynamo" - google Reelight.
Also, "no friction" is weaselly. There is certainly drag.
There's no free lunch. If you want X power to run a light, you need to draw that much power off the wheel, plus generator inefficiencies. Also, how is something that's just slapped on the side of a wheel going to be as efficient as a generator hub that's designed for the purpose?
They are certainly NOT the "first compact contactless bicycle dynamo" - google Reelight.
Also, "no friction" is weaselly. There is certainly drag.
There's no free lunch. If you want X power to run a light, you need to draw that much power off the wheel, plus generator inefficiencies. Also, how is something that's just slapped on the side of a wheel going to be as efficient as a generator hub that's designed for the purpose?
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#22
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So, they took a Reelight and added a capacitor.
They are certainly NOT the "first compact contactless bicycle dynamo" - google Reelight.
Also, "no friction" is weaselly. There is certainly drag.
There's no free lunch. If you want X power to run a light, you need to draw that much power off the wheel, plus generator inefficiencies. Also, how is something that's just slapped on the side of a wheel going to be as efficient as a generator hub that's designed for the purpose?
They are certainly NOT the "first compact contactless bicycle dynamo" - google Reelight.
Also, "no friction" is weaselly. There is certainly drag.
There's no free lunch. If you want X power to run a light, you need to draw that much power off the wheel, plus generator inefficiencies. Also, how is something that's just slapped on the side of a wheel going to be as efficient as a generator hub that's designed for the purpose?
With high power LEDs one can reach appr. 80 lm/W, while the Cree LEDs used in Magnic Light deliver ~160 lumen per watt. This is possible because we feed each LED with less than 1 watt, which results in the ability to operate at temperatures below 35° C. This way, we harvest roughly 46% of the theoretical maximum white light, and hence 4 times more than standard LEDs.
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No, there's more to it.
The reelights have magnets mounted to the wheel. These do not.
These are only the light unit with nothing else mounted to the wheel, which certainly is revolutionary. Apparently it works based on eddy currents generated in the rim?
With nothing else mounted anywhere but the light itself, they are more compact than the Reelight. Does that make their statement correct? That's a judgement call.
I don't quite understand how they've gotten this to work, but they seem to be shipping and I'm not hearing about people receiving theirs and saying it doesn't work as advertised, so ... it seems to be real.
Agreed. Though if we use the "the resistance that one surface or object encounters when moving over another" definition, their statement is technically accurate. But weaselly, as you said.
I don't know how efficient it is, but from what I understand hub generators are around 50% efficient, so if true (and I'm far from sure on that), there's room for improvement.
That said, they've not really given any information on how much electricity is generated and how much drag, so I have no idea if they are more efficient than that or not.
The reelights have magnets mounted to the wheel. These do not.
These are only the light unit with nothing else mounted to the wheel, which certainly is revolutionary. Apparently it works based on eddy currents generated in the rim?
They are certainly NOT the "first compact contactless bicycle dynamo" - google Reelight.
I don't quite understand how they've gotten this to work, but they seem to be shipping and I'm not hearing about people receiving theirs and saying it doesn't work as advertised, so ... it seems to be real.
Also, "no friction" is weaselly. There is certainly drag.
There's no free lunch. If you want X power to run a light, you need to draw that much power off the wheel, plus generator inefficiencies. Also, how is something that's just slapped on the side of a wheel going to be as efficient as a generator hub that's designed for the purpose?
That said, they've not really given any information on how much electricity is generated and how much drag, so I have no idea if they are more efficient than that or not.
#24
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As a onetime owner of a Magnic Light, I can assure everyone that it is real, it works, and works pretty well. (I also wrote the review linked above.) It isn't magic as the name implies, but it does use a different means to generate power, one that you wouldn't expect.
The movement of ANY conductor generates eddy currents. In this case, the aluminum rim of your wheel is a rotating conductor and it generates the current. The magnets inside the light then move to generate the electricity that powers your lights. This works even though the rim is non-ferrous.
The real engineering feat here isn't the "magic" of the eddy currents, it is harnessing them in something small and light enough to put on a bike.
Look at the video on the kickstarter and you can see how this thing is built.
The movement of ANY conductor generates eddy currents. In this case, the aluminum rim of your wheel is a rotating conductor and it generates the current. The magnets inside the light then move to generate the electricity that powers your lights. This works even though the rim is non-ferrous.
The real engineering feat here isn't the "magic" of the eddy currents, it is harnessing them in something small and light enough to put on a bike.
Look at the video on the kickstarter and you can see how this thing is built.
Last edited by zacster; 01-02-14 at 03:41 PM.
#25
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I don't think the name was intended to imply magic, unless it's in a different language. I have to say I was a skeptic, but a lot of us didn't think about the spokes playing in the physics of it. It's really a pretty amazing invention