Originally Posted by
igarocom
The transorb will be for spikes not over-voltage protection. The LED in that light isn't enough to keep the voltage below 10V, are you sure there isn't something after the rectifier doing over-voltage protection? I would expect a 10V cap to go to 6V, which incidentally is what Son Edelux 2 keeps it at. It makes me think there's another piece.
I haven't gotten far in reverse engineering the light. Mostly just the transorb and bridge rectifier... which is pretty obvious. The 10V electrolytic cap is connected directly at the output of the bridge rectifier, so there's no series voltage regulator protecting the cap.
The rest is just a little microcontroller, an inductor to buck the voltage down for the LED(s), and a ton of small transistors or diodes.
My best guess at this time is that the light must use the "daytime running light" LEDs as a way pull down the dynamo voltage to a level that is safe for the 10V cap.
I was given this light because it's dead. It's entirely possible that it isn't designed to tolerate a dynamo run at high speed.
I haven't figured out why it's dead, so any guess about the cause of death is reasonable. No components blown up, though.
Pics attached below...
Steve in Peoria