V G wrote:
> I'm looking to build a simple battery-powered charger for my mobile
> phone. I'm out a lot where it's not convienient to plug my phone into
> a wall outlet.
>
> The charger will simply consist of a power supply that provides 5
> volts via a USB socket. I want to power it with 4 AA NiMH batteries
> (Sanyo Eneloops). 1.2 * 4 =3D 4.8, so I will need to use a boost
> converter of some sort to output 5 volts.

Not necessarily.  USB voltage at the device can be from around 4.3 to 5.5
volts worst case if I remember right.  Probably the phone contains a
switcher to charge its battery and you don't need to be right on 5 volts in=
..
Give it a try with a variable power supply to test it.


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