Has anybody direct experience with B&M E-Werke universal converter when combined with an hub-dynamo like SON20R/SON28?
Is it in such a circumstance the output voltage limited to 7 V as stated in the relevant data-sheet supplied by B&M for E-Werke ?
In other words when does it apply the following statement:
"The E-WERK works with all hub and tire driven dynamos without electronic voltage limitation. Connected to dynamos with integrated limitation, the E-WERK can give off a maximum of 7 V"

Thanks a lot for any attempt to clarify such technical issue.
ConRAD

http://www.nabendynamo.de/produkte/pdf/Ueberspannung.pdf

This document states that you should add an external device to the circuit on you bicycle to limit the voltage of the dynamo. From my point of view it would make no sense to use a voltage limiter inside the dynamo because it would try to limit the voltage even if the lights are completly switched off. This would draw a lot of power from the dynamo just to burn it in the limiter... Nobody wants this ;-)

The only practical solution is to put the limiter behind the light switch and therefore it is normally located in the front reflector.

To cut a long story short: You shouldn't experience any problems with the SON, I think, without warranty of course!

Thank you Tobi, I like your explanation because it sounds totally credible.
At this point, I would appreciate B&M to revise their statement accordingly

Thank you again
Corrado

There is nothing wrong with their statement. If the hub dynamo has its own voltage limiter, then the E-Werk can supply no higher voltage than 7 Volts. If the hub dynamo has no internal limitation, then the E-Werk can supply the full output range.

SON hub dynamos have no internal limiter. It is in the backlight cable supplied by Schmidt, which you should use with limiting function behind the light switch if the headlight has no limiter at all..

OK, I agree. Just now, oscilloscope on the handle-bar, I verified that:

1. With front light switched-off: e-werk output is 13-14V, 25Hz approx

2. With front light switched-on: e-werk output stabilizes at 7V, 25Hz approx

Thank you and best regards.

ConRAD

I apologyze, ... so far I've got somehow confused.
The right statement is:

1. With front light switched-off: dynamo output is 13-14V, 25Hz approx.
In turn e-werk max output is 13.3 Vdc.

2. With front light switched-on: dynamo output stabilizes at 7V, 25Hz approx.
In turn e-werk max output is 7 Vdc (actually a bit more at no-load conditions).

ConRAD