I've looking for a way to charge my electronics while I excercise on my bike. I couldn't find dynamo powered USB charger so I decided to try and make one. I used what I could find and cobbled it together based on information from Instructable and other on-line sources.
Step 1: Installing the Dynamo
Step 2: Rectifying and Regulating the Voltage
I then had to regulate the voltage and amperage to an USB standard rate of 5.5vdc and 500Ma. I found it easier to recycle a car lighter USB device to do the work for me rather that building something. Safer for everyone involved. :)
The output for the car lighter USB device says it should be 5.5vdc and 700Ma but testing both in the car and on the bike showed 5.5vdc and 950Ma. Since I've used this device a lot in the car, I'm accepting these figures as safe and fine. If you think otherwise, please let me know.