Originally Posted by
john bono
Number one on my list is a dynamo driven usb/automotive charging point. I have that, I can charge my ipod, cellphone, gps, headlight, nimh batteries etc. 3 - 4 watts of sustained power via a dynamo in an easy to use package would just about make my day.
Bridge rectifier converts AC from dynamo to DC.
Batteries regulate and filter power for USB device.
Switch selects LED headlight-off-USB circuit.
USB devices can be recharged by the batteries while the headlight is powered from the dynamo.
The dynamo will produce 500mA which is the suggested rapid recharge rate for Ni-MH batteries. Simply calculate how much time is required to recharge the batteries at 500mA and use your cycle computer trip time to automatically keep up with recharge time. It will stop and start as you stop and start riding. USB devices can use up to 500mA. Devices that use less then 500mA allow you to power the device and recharge the circuit batteries slowly as you ride.