The connector & battery conspiracies

[john bono]

I'm planning to do a tour in about 7 weeks, and I want to bring lights, still and/or video camera, cell phone, ipod, etc with me, but I've run into a problem--everything takes a different charger, and/or a different battery, meaning I need to bring a bunch of separate chargers for all my techno doodads, adding unnecessary weight. I want to set up to standardize everything on AA batteries and a usb based charger. Anyone have any ideas for dealing with this?

[n4zou]

Here is the circuit I use.
http://i143.photobucket.com/albums/r154/n4zou/DynamoUSB-1.jpg
The 4 Ni-MH batteries filter and regulate the power for any USB device plugged into the USB connector. If your device can be recharged and/or powered by plugging it into a USB port this circuit will work fine.
The batteries must be solder tab types so there is no possibility of a poor or open connection which would allow unfiltered power to flow into your device possibly damaging it. The suggested rapid recharge rate for Ni-MH batteries is 500mA which happens to be the output of a typical bicycle dynamo. If your Ni-MH batteries need to be recharged simply disconnect any device plugged into the USB connector. This type of recharging must be manually controlled. Simply calculate the time required to fully recharge your batteries at 500mA. Reset the trip time on your cycle computer and when it reads the calculated recharge time simply disengage the dynamo. The switch will electrically disengage hub dynamos and should be opened with mechanically disengaged tire driven dynamos as well. The headlight uses high power LED emitters rated at 1 amp. The capacitor reduces low speed flashing. For details on building dynamo powered headlights see this link.
http://pilom.com/BicycleElectronics/BicycleElectronics.htm
Power LED's can be obtained here. http://www.dealextreme.com/products.dx/category.917