.. just wondering where and when the universal “3W” standard power size, commonly used for bicycle generators, did it come from.
I know why.
There was an old german Law of the for traffic.
in this law, all bicycle components where rated at 15 km/h.
A 3W Bicycle Dynamo had to power the 2,4 w front bulb and the 0,6 W rear bulb (3W) at 15 km/h at full Power.
Today, with LED Equipment, it would be more interesting to know the mAmpere, that are delivered.
Because the Volt are depending on the Speed.