Originally Posted by
JohnJ80
Yes, I understand all of that (I'm an electrical engineer).
A dynamo is not an infinite source of power. Presuming it was designed for these markets, it was designed ultimately with the 3W limit in mind. That, plus some engineering margin - say 10-40% or so, is likely what it was designed to provide not a 300% increase. And these circuits have no information on the dynamo itself and it's specs. Could work and it might be reliable, just saying it's worth some caution. Reliability is where it most likely would fall down. Right now, it's a known unknown. That's all I'm saying.
Then again, I'm not sure why anyone would feel the need to go to all this effort when there are a lot of lighting choices around that solve this problem without the need for modification. There is the hobbyist motivation, I suppose.
On the issue of government regulation - it seems to me the Netherlands have the right idea (essentially stay out of it) compared to the Germans. Bike lights are not a problem. We may approach that in the future as the technology improves, but almost with exception it's not a problem.
J.
They're made to a price point first and foremost. A new Shimano dynamo hub is less than €25. So, it's probably cheaper to overbuild the specs with lower quality materials and then down regulate the Amps.
Everyone else can stay out of it because the Germans control almost all EU regulation ... including bike lights. Without German regulations, we'd still have expensive and poorly engineered dynamo lighting system (or the junk that one sees in the US like Magic Shines.)