It would probably not work. 500 mA is not enough to charge this PDA. At least not while using it. I tried numerous things before building the charger. I ordered an USB charger from Hong Kong and it is was not working even plugged on a 12VDC to usb converter. I tried a 1 Amp. car charger and it was not working too.
The wall charger is rated at 5 volts, 2 amp. It is outputing 5.25 volts when not plugged to the PDA. The L7805C that I am using is rated at 1.5 amp.
As I said, I tried many things but to make it short, I found out that the gage of the wire used is very important. The unit I got from Hong Kong was not working, even when connected to a computer power supply (5 volts, many amps). Changing the cable for an heavier gage one made it work.
After consulting the datasheet of the L7805C I found out that the 0.006 amp. that I was talking on my previous post is the quiescent current of the regulator, not a floating charge used by the PDA.
I made a mistake and I wonder if it is of any consequence. The L7805C datasheet specify a 0.33 uF and a 0.1 uF capacitors to be used but I used instead a 0.22 uF and a 0.1 uF. This is what was recommend in an other datasheet that I consulted for a 7805 before building the charger.
Anyway, I am happy with this not so efficient charger. What is important is that it is working and besides, I like it's "kool" look.
Alain