For those of us who bike regularly, whether it be for commuting, sport, or just for fun, a decent lighting system is not only necessary for safety at night, it’s also required by law in most places.
Cyclists generally have two options when it comes to lights: battery power or dynamo power. Battery power is reliable, easy, and cheap, but has the obvious drawback of replacement cost when the batteries run out. Dynamo powered lights use your bike’s spinning wheels to generate power, and therefore don’t require batteries. The downside is they cause friction that can slow you down, and they’re generally more expensive.
German inventor Dirk Strothmann, however, has come up with a device that aims to alleviate both problems. The Magnic Light (portmanteau of “magnet” and magic,” we assume) is a compact, contactless, dynamo-powered bicycle light that at first glance appears to run on magic.
While watching the video on Magnic Light in action, its hard to believe that it’s real. Strothmann, who’s no doubt used to getting mesmerized looks, feels compelled to assure us that it’s not a trick. He explains that, rather than some sort of German witchcraft, the Magnic Light uses what are known as eddy currents to power its LED’s.
Even if physics and electromagnetism weren’t your strong suit back in high school, its relatively easy to grasp how eddy currents work. Think of a canoe paddle moving through the water. As it travels backward breadthwise, small swirls of water are created along it’s edges, and remain swirling for some time after the paddle is removed from the water. These are eddy currents, and although this example is with fluid, the same phenomenon occurs with electromagnetic fields. For a more visual explanation, check out this video.
When your bike’s spinning rim (the conductor) moves past Magnic Light’s built-in magnet, it creates an eddy current that powers a dynamo, thus producing electricity to illuminate its two LED’s.
But it’s more than just a cool headlight — certain design features give it some added benefits. Because the lights are situated next to your tire rather than on top of it, their glow illuminates your rims and makes you more visible from the side. The brake light has an interesting feature as well. If you attach the light to your brake pads, the light gets slightly closer to your rim when you brake, thereby increasing the strength of the eddy current it creates and causes the light to glow brighter. This would make for an effective way to signal when you’re slowing down, and hopefully ensure you don’t get squashed by any following vehicle.
As the product hasn’t shipped just yet, the only way to gauge performance is from the comparison Strothmann does in his video pitch. Compared to most other dynamos it looks like Magnic Light generates much more light and much less friction. The glow looks somewhat flickery, and not as constant as battery-powered lights, but not to the point of being problematic.
Although a price hasn’t yet been set for the Magnic Light system, its Kickstarter page is somewhat telling. The cost for backers was $199 – and considering the fact that early backers generally get items at lower-than-retail prices, we wouldn’t be surprised if Magnic Light sold for $220 to $250 once production is finished. A bit on the expensive side, but for the everyday cyclist, this neat little gadget could save you money on batteries in the long run.