Our Story

The idea for Magnic Light came up on June 18th, 2011. After an in-house pasta party in "preparation" for a local 6 mile night race the next day (The Night of Borgholzhausen) we did some experiments on eddy current brakes for road bikes. Talking about the basic mechanisms and in particular the useful property that aluminum rims can be used for magnetic brakes, although aluminum itself is not magnetic but still conducts electricity, we came up with a cool idea: if we can use aluminum rims for eddy current brakes, the opposite should also work! It should be possible to build a bicycle dynamo that absorbs the magnetic force from the rim without contact, instead of braking the rim. Luckily we had masses of magnets lying around in the apartment to do little experiments with: all those small medium-strong toy magnets that children use to build nice magnetic creatures. These were strong enough to run some encouraging experiments. We found that the magnetic fields of the eddy currents induced in the rim can be absorbed to generate electrical energy. The only question was whether that would be ridiculously little or even quite decent. Although we were still a long way from having a working dynamo, we did have an approach to pursue. Anyone can check for themselves that there is no magic at play here: Take a magnetic ball (you can get this in various toy stores) and let it roll around in a (non-magnetic) aluminum pan or on several layers of aluminum foil. The magnetic ball is held by the pan as if it were magnetic! What happens here is a well-known electromagnetic effect: Since aluminum conducts electricity, eddy currents are induced by the rolling ball, since there is a relative movement between the ball and the socket. These eddy currents now have a magnetic field of their own that attracts and thus holds the ball. Nothing else happens with the rim. Similar experiments can be found in the literature or on the Internet (more details can be found on e.g. Wikipedia). Although prototype number 1 never produced electricity, it brought a lot of inspiration.


... to be continued ...