But also we realised, that so far, filming wasn’t considered in our photosharing-concept. For some people it is a big difference whether they are filmed and then appear online or if it’s just photos of them. So we added another option about filming to the sheet, that is passed around during the tour.
Picking a circuit for the dynamo-powered USB port

On the Spring Meeting, we did some experiments with different types of dynamo-powered USB ports: Once with a high-dropout DC-DC convertor, once with a low-dropout DC-DC convertor, once with a Zener diode, once with a step-down convertor (an old one, I don’t know which model it is, it cost around 10 €) Once with a double 3300 µF capacitor for boost (as described here), once without Once with a silicon rectifier, once with one made of Schottky diodes We connected these regulators to a Shimano DH-3N30 hub dynamo, and connected a 10 Ω resistor that should simulate the charging device (500 mA at…