YEAH!!!!
Behold! I finally upgraded my [bike sound system], adding extra power, a subwoofer and a battery charger for everlasting supply. It doesn’t look as decent as the last one did but it totally rocks. The first test run was a trip to the [Fusion Festival], around 120 kilometers. The dynamo provides enough power to reload the batteries while the system is playing.
I started of with the [TDA7052] 1W amplifier I had already used with the old sound system, only this time I used two, one for bass and one for mid/high frequencies. But the TDA is made for 8Ohm speakers and my bass speaker had 4Ohms and so had the two high/mids in parallel. So I decided to get something bigger. Now I have an [AN7148] delivering 2×2,5W at 12V 4Ohm which is totally sufficient to predominate the occurring head wind and most traffic noise :)
The battery charger was built according to the circuit provided by [forumslader.de] . Documentation is in German only but it’s extraordinary! It’s housing has still to be completed. To be done in time for the Fusion Festival I was a bit in a hurry.
The AN7148 in its housing. Batteries (9xNiMH) sit at the right.
The battery charger
