Carlos Nazareno wrote: > Hey guys. > > I haven't taken that much look into foot pedal chargers and do know > what their internals look like -- I just remembered coming across the > link I posted so I shared The efficient way to do a foot pedal powered > generator would probably be to have a small weighted wheel spin as a > dynamo when you step on it? > > You just keep pumping on the pedal to keep the wheel spinning and it > shouldn't take much effort, the wheel's momentum should keep power > flowing.
Basically, never do mechanically what you can do electrically. There are cells now which are reasonably light, cheap, and can take 30W charge. http://cgi.ebay.co.uk/Lifepo4-A123-Cell-26650-2300mah-3-3v-battery-3-Pcs-NEW-/260726135323?pt=US_Batteries&hash=item3cb47d1a1b for example. A flywheel is going to be _lots_ heavier. My design that I posted about earlier in this thread had basically a 'gearbox' electronically that optimised charging of the battery at the optimum biodynamic speed, and then used the generator as a motor to pop up the pedal back to the operating position. It was designed to get enough charge to charge a mobile phone battery fully by an adult over 3-5 mins. This is only at best 50-30W or so. If you want something to generate power efficiently, you need to use both legs - either a cycle, or a step-machine. Cycles are rather more efficient than step machines though the mechanism is pretty much inherently bulky. _______________________________________________ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
