First cycling days from Strasbourg to Nancy

On Monday we started cycling from Breuschwickersheim. We had 4 days scheduled to do 155 km, a lot of time to develop a daily routine and to have a buffer in case something goes wrong with the bikes or trailers. We even managed to all leave around 1 pm on the first day, which is a record by far among the last years. Cycling was quite hard despite only doing between 30 and 40 km per day. The summer came back with some really hot sun, and the road went up and down a lot through the Vosges mountain range.…

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Picking a circuit for the dynamo-powered USB port, part 2

Ecotopia Biketour 2017 is already under way and updates about how our first days of cycling went will follow soon. One thing that we want to achieve this year is not rely on the electrical sockets of our hosts anymore when it comes to charging the numerous electronic devices that people are bringing on the tour these days. One way to do that is to build a circuit that converts the power coming out of the dynamo of a bike to power that is needed to run a USB port. We have tried to find the best way to build…

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Spring meeting 2017

Eleven of us (plus two dogs) met on the week-end from the 14th to the 16th of April in Freiburg, Germany, to work on the preparation of the upcoming Biketour. The venue was the public café of the housing cooperative SUSI. SUSI is several former military barracks that were bought by a collective using the Mietshäusersyndikat, and association that makes it easier to get a loan for buying houses collectively, while at the same time making sure that these houses can never enter the capitalist real estate market again. The complex is huge, with space for 285 people to live and…

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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…

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