Jameco sells these memory backup capacitors:

http://www.jameco.com/cgi-bin/ncommerce3/ExecMacro/jameco/home.d2w/report?cgrfnbr=657&ctgys=503;516;657;

They have a high capacitance, but a low voltage rating to keep them smallish.
Not sure how small of a cap you need, but this may be a place to start.

Eric

On Mon, 9 Feb 2004 11:21:25 +1300
Jinx <joecolquitt@CLEAR.NET.NZ> wrote:

> > i=C dV/dT calculation is indicating over 1300 uF
> > .............
> > fairly unreasonably large capacitor for this circuit.
>
> A 5V 0.1F isn't much bigger than a button cell. I strip them out
> of old VCRs all the time. And some are up to 1F
>
> --
> http://www.piclist.com hint: The PICList is archived three different
> ways.  See http://www.piclist.com/#archives for details.

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.