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…