Archive for the ‘Electronics’ category

Bicycle USB charger using a hub dynamo (update)

June 1st, 2010

This is an update on my previous post about a hub-dynamo driven (USB) charger.
A step by step guide is posted here

The latest incarnation is a stripped down version of the original. I left out the input tuning C2, C3, R1 (see original post for the diagram) and replaced the 4 Schottky diodes with an integrated bridge rectifier. The Schottky diodes  are more efficient due to the lower forward voltage drop, but require more soldering and space.  This version now fits into a small ABS case. I hope to replace the fixed USB cable with a USB A receptacle (if it fits).

usb dynamo case

usb dynamo case layout