Bicycles

Magnic Light claims new form of no-contact bicycle dynamo lighting

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The Magnic Light is a contactless dynamo bike light, that reportedly utilizes eddy currents to produce electricity
The Magnic Light is a contactless dynamo bike light, that reportedly utilizes eddy currents to produce electricity
The Magnic Light is a contactless dynamo bike light, that reportedly utilizes eddy currents to produce electricity
The Magnic Light head and tail lights
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Despite the continuous advances being made in lithium-ion battery technology, many cyclists still prefer to use dynamo-powered lights on their bikes - there's no having to remember to recharge the batteries, no subsequent forgetting to put the light back on the bike, and no worrying about the batteries unexpectedly giving out mid-ride. Dynamos, however, have their own drawbacks. Friction-powered sidewall units slow the bike down and wear out the tire, while dynamo hubs must be built into the wheel, and add to the bike's revolving weight. Now, however, German inventor Dirk Strothmann has created what he claims is a better alternative - a small, no-contact, self-contained dynamo bike light.

According to Strothmann, his fork- or brake caliper-mounted Magnic Light works with any type of metallic wheel rims. While other contactless dynamos do exist, those incorporate wheel-mounted magnets. Dirk's product, however, has the magnets in the dynamo, and utilizes eddy currents. In a nutshell, these are electrical currents that are induced in a conductor, when that conductor is exposed to a changing magnetic field.

"Relative movements of magnets and neighbored conductive material induce eddy currents in the conductive material - in our case the metallic rim," Dirk explains on his Kickstarter fund-raising site. "These eddy currents have their own magnetic fields which are absorbed by the Magnic Light generator kernel and by this way produce electric energy."

The Magnic Light head and tail lights

This phenomenon apparently even works with aluminum and magnesium rims, as the rim material only needs to be conductive, not magnetic. He states that there is a slight braking effect on the wheel, but that it is less pronounced than that caused by traditional sidewall dynamos. As can be seen in his pitch video below, the light output does appear to warble slightly, in time with the spinning of the wheel.

The light itself is produced by dual CREE LEDs, which at approximately 16 mph (26 km/h) are said to kick out a respectable 150 lumens. In its present prototype state, the Magnic Light simply turns off when the wheel stops turning. If there's sufficient consumer interest, however, a future version might include a capacitor to keep the bulbs burning while the bicycle is stopped.

It all perhaps sounds a little fishy, but Strothmann says that the public can come check the system out for themselves, when his light is on display at the FAHRRAD bicycle trade show in Essen, Germany, from February 24th to 26th - potential investors might want to wait until after then before sending in their money!

For people who are interested in funding the project, a pledge of US$199 will get them a front and rear light, when and if the funding goal is reached, and the light goes into production. A pledge of $130 will get them a front light only.

Source: Kickstarter

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26 comments
Anders Nissen
Isn\'t that quite similar to the Reelights which we\'ve had for years? http://www.reelight.com/
Tobor
The problem this unit shares with older dynamo designs is that when the bike slows down and or stops the light output is weak to negligible. Many if not most accidents occur at intersections where the bike is just picking up speed from a dead stop while an errant motorist may try unsuccessfuly to beat a stale traffic light and not see the dim dynamo output leaving the cyclist vulnerable at a most critical time. Needs capacitor!
Slowburn
re; Anders
No it not. The Reelight requires you to mount the magnets onto the spokes, this creates a weak magnetic field in your rim. I think I prefer the Reelight.
Charles Gage
It would seem to me they could wire in a capacitor to even-out that flickering and also provide enough capacity to maintain the light for a short period of time after stopping.
Bruce H. Anderson
If this conversation were regarding lights for an automobile that were illuminated only when the car was moving, it would be absolutely laughable. Get a grip! Or at least a capacitor.
Stewart Mitchell
I\'ll believe it when I see it in the stores. It looks like a fake system using batteries
Stewart Mitchell
Is there magnets inside the tire?
see3d
I really took offense at the tone the author took at the end that this might not be a really possible. Anyone who knows anything about magnets and motors knows that this is not only possible, but is the principle on which many AC motors operate. However, I completely agree with the comments that it needs a capacitor to keep the light burning for a few minutes (at a lower brightness), after the bike comes to a stop. Watching the video should help answer questions about how well it works. If I rode a bike, I might consider this.
Steve Rock
I don\'t get it either, the created opposing eddy current would be static relative to the magnet creating it. Wouldn\'t it ? Otherwise, why not make your own generator for your own lights ? I cant find anything on the net to support this principal yet, please somebody prove me wrong !!
vortexau
WHY do those who comment not read the full text of the article?
Posts repeatedly comment on the Items failure to remain lit with a stationary bicycle. Plainly shown in the article is the following text: \"In its present prototype state, the Magnic Light simply turns off when the wheel stops turning. If there\'s sufficient consumer interest, however, a future version might include a capacitor to keep the bulbs burning while the bicycle is stopped.\"
Another case of \'Foot-in-mouth\' for Posters?
vortexau