On 2012-10-18, Mike S <mi...@flatsurface.com> wrote: > re: using gold caps > > You may wish to consider rechargeable lithium cells, which will give you > a more consistent voltage than a capacitor. I'm not sure how voltage > sensitive the Oncore boards are for holding data while powered down, but > these are what Motorola used in the ones with the on-board battery option. > The high Farad capacitor will charge to just a little under supply voltage in about 24H. My Oncore seems to keep the RTC running and the almanac valid for about a month after power off. That part of the Oncore seems to draw in the very low nano-amp range. The capacitor has enough charge after about 3 hours to be useful for short power blips. I also thought about Lithium rechargables in searching for this solution, but found that the high Farad capacitor was a drop in replacment on my TAPR board. It fit in the exact footprint of the coin cell holder and all that I needed to do is replace one resistor with a jumper wire.
Tom -- Public Keys: PGP KeyID = 0x5F22FDC1 GnuPG KeyID = 0x620836CF _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
