Today, a friend of mine, Gerben, gave me a birthday present (a tad late). Not the usual beverages (turned 18 ) (usual, but still very well appreciated ), but a home-made portable speaker with built-in amplifier. Here seen making more sound than the internal speaker of my Thinkpad:
It’s a nifty little device: it’s powered by either an internal battery or an external power source.
It contains a voltage converter and a rectifier which allows a variable AC power source to be connected. This has been added to be able to connect the speaker to the electrical generator of a bicycle. Why? The previous version of this speaker was taken on the bicycle trip with a few friends to the Hertog Jan Brewery in Arcen (~70km) which was only powered by a battery (which tends to be exhausted).
Even better, when set into external source mode it recharges the battery. And because of the voltage converter, the sound doesn’t get louder when you are cycling faster, but the quality of the sound gets better!
I’ve had quite some fun dissecting the little device. Thanks again Gerben!