More and more people are using bikes when they are traveling or commuting. It's a nice way to travel, especially during the summer. One of the problems of using your bike is that you usually can't charge your phone or other gadgets while you're riding. This hack solves this matter.
It seems obvious that you could in some fashion adapt an old school dynamo to charge your gadgets. Dynamos used to power bicycle lights. However, in recent years, much brighter and efficient LED lights have taken over. This didn't stop Dbc1218 from Ohio from working out how he could charge his gadgets on his daily commute.
This USB Bike Generator produces enough power for two USB ports, which are good to basically charge anything from your iPhone to your iPod, and anything in between. Most gadgets can be charged by a USB port. If they can't, adapters exist so that they can use the ports. This isn't Dbc1218's first try at making something like this. It's his third revision.
-USB car power adapter
-8 1N4001 Diodes
His new revision includes a more efficient switching regulator. This device is available from Dimension Engineering. Stepper motors are available here. The stepper motor needs to be 5V and generates 3.3 amps. In order to put the electronics together, Dbc1218 has put together an in-depth guide with pictures and notes to aid your build. The final part involves creating a mount for the whole device. The difficulty of this build is soldering and putting together the electronics.
The USB Bike Generator will power two USB ports as you ride your bike. The system is 70% efficient at speeds above 12 mph and will generate adequate power at 7 mph. He reports that because of the varying power that is generated by this device, he had trouble completely charging an iPod, but all in all, it's a great idea to make something like this. If you'd rather purchase a generator like this instead of building your own, Dahon makes one and it will cost you $100. However, this generator will be able to charge your favorite iPod.
[Instructables via Lifehacker, photos by Dbc1218]