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-   -   Kickstarter Light technology (http://www.bikeforums.net/electronics-lighting-gadgets/798881-kickstarter-light-technology.html)

lawrencehare 02-15-12 11:04 AM

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...
---
Has anyone seen this http://www.kickstarter.com/projects/...ergy?ref=live?

It looks pretty good - I think I'll jump in on this one...

Lawrence

2_i 02-15-12 11:15 AM

Quote:

Originally Posted by lawrencehare (Post 13854975)
It looks pretty good - I think I'll jump in on this one...

Don't waste your time nor money.

RB1-luvr 02-15-12 11:27 AM

that seems pretty cool.

I've backed a cool aluminum pen that should ship this month. This might be the second project I back.

2_i 02-15-12 11:32 AM

Quote:

Originally Posted by RB1-luvr (Post 13855082)
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 am wondering whether I could interest you in this bridge, given 'luvr' be that Eiffel Tower, I have on sale:).

10 Wheels 02-15-12 11:36 AM

$25 and you get a shirt with your new lights.
  1. 25 + YOU SELECTED
  2. The Shirt: Get a personalized high quality functional shirt with the project logo and your name.
  3. Est. Delivery: Apr 2012

Burton 02-15-12 02:04 PM

The idea sounds kinda cool but there's absolutely no specs as to light output. Not even a guess-timate!

socalrider 02-15-12 02:43 PM

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.

Clem von Jones 02-15-12 04:09 PM

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.

Looigi 02-15-12 04:48 PM

The light output is specified as 150 lm on their website.

rscamp 02-15-12 05:41 PM

This doesn't pass the "no free lunch" rule.

2_i 02-15-12 05:49 PM

Quote:

Originally Posted by rscamp (Post 13856768)
This doesn't pass the "no free lunch" rule.

Both perpetum mobile and religion are here to stay;).

Aushiker 02-16-12 07:06 AM

Quote:

Originally Posted by socalrider (Post 13855990)
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.

It states US$200 to the supporters on the link given.

Andrew

cpach 02-16-12 11:03 AM

Quote:

Originally Posted by rscamp (Post 13856768)
This doesn't pass the "no free lunch" rule.

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.

2_i 02-16-12 11:10 AM

Quote:

Originally Posted by cpach (Post 13859261)
Regardless of whether their idea works well in practice

Why should such essential issue be disregarded? There are tons of effects in nature that can generate emf, but they can be ridiculous in effectiveness of generating electric power compared to a basic dynamo.

minisystem 02-16-12 11:43 PM

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.

minisystem 02-16-12 11:46 PM

Quote:

Originally Posted by minisystem (Post 13862504)
The brake light function is nifty, but the change in light output of the front light with braking might be weird/distracting.

um, except that braking with a conventional dynamo also causes a change in light output. :o

I guess I could get used to having more light when braking instead of less.

gn0me 02-19-12 05:34 PM

i don't like how the light is mounted on one side of the rim. it won't be very visible, if at all, from the opposite side.

Lalato 02-29-12 10:13 PM

Quote:

Originally Posted by gn0me (Post 13873095)
i don't like how the light is mounted on one side of the rim. it won't be very visible, if at all, from the opposite side.

Looks like you can mount one on each side if you like. Not a perfect solution, but it would eliminate the problem you describe.

JonnyHK 01-02-14 01:59 AM

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.

http://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

01 CAt Man Do 01-02-14 07:57 AM

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.

ItsJustMe 01-02-14 08:54 AM

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?

01 CAt Man Do 01-02-14 02:48 PM

Quote:

Originally Posted by ItsJustMe (Post 16375301)
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?

While I don't propose to understand everything about the physics, according to what was written ( which I skimmed over ) the unit doesn't produce the same amount of power as a typical dynamo. It just uses the power it produces more efficiently ( see below ).

Quote:

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.
The thing I like about it is that it should be able to transfer easily from one bike to the next without much problem. They also include two different UI, ( for the rear ) one for the Germans and one for us which I think was a super smart thing to do. Now add to that; If I can buy one front light for less than $100 ( even if max output is about 160 lumen ) it sounds like the money spent may be well worth it if I never have to worry about having to run out of battery juice. For winter commutes it could be just the thing to give the dedicated battery lamp user some added peace of mind. :thumb:

dougmc 01-02-14 02:50 PM

Quote:

Originally Posted by ItsJustMe (Post 16375301)
So, they took a Reelight and added a capacitor.

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?

Quote:

They are certainly NOT the "first compact contactless bicycle dynamo" - google Reelight.
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.

Quote:

Also, "no friction" is weaselly. There is certainly drag.
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.

Quote:

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?
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.

zacster 01-02-14 03:06 PM

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.

unterhausen 01-02-14 04:51 PM

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


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