On 27/05/2011 10:07, David wrote:
> All,
>
> I am building a small PIC based IR sender which will attach to a
> moving object.
>
> As there is no power source it will have to be battery powered.  I was
> thinking of 3 AA batteries with an in-circuit charger.  The IR LED has
> a Vfwd of 1.5v, I can pick a PIC that will operate at 3v.
>
> So two easy questions:
>
> 2) Is there anything better than simple AA batteries?

it depends on what your goals of run time/power consumption, size,=20
weight, design complexity, volume.

Choice is 1, 2, 3 or 4 AAA or AA or one or two LiPoly.
3 x NiMH is in reality 2.7V (near exhausted) to 4.1V (fresh charged).
LiPoly / various Li systems are  about 3.5 to 4.2V

4 x NiMH is  about 3.6V to about 5.5V.
1) So running a buck regulator of 4 x AAA or 4 xAA or one Li cell for=20
3.3V supply is feasible.

2) Running boost regulator MFP1640, LT1073 of 1 x AA or C cell to 3.3V
or
1, 2 or 3 NiMH (AAA or AA or C) OR one LiPoly  to 5.V

Or if consumption is low and intermittent then a MFP1640 off 1 x AA=20
alkaline to 3.3V may be appropriate.

> 3) Recommendations for your favourite battery charge IC, so I can go goog=
le.
>
> Thanks,
>
> David

--=20
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