-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 18/10/2012 14:22, Thomas Laus wrote: > On 2012-10-18, Thomas Laus <lau...@acm.org> wrote: >> Ron: >> >> I am also using this same board and made a discovery a few years >> ago that this backup battery discharges over a period of time, >> normally less than a year and is not available when 'really' >> needing it. There is a battery charging current available on Pin >> 3 of your Oncore that can be used to charge a 1.5F 5.5V Gold >> Capacitor. I used the Digikey part P11063-ND for mine. It will >> mount in the same loacation as the coin cell. You will need to >> jumper out R2 (820K) and just connect the high Farad capacitor >> between pins 1 & 3 on your Oncore. Watch the polarity! The >> charging circuit in the Oncore is current limiting and it will >> take about 12H for enough charge to hold the almanac between >> powerups. When the capacitor is fully charged, the almanac stays >> for about a month. >> >> You really can't do without a battery. Your almanac information >> and current date and time is stored in the Oncore RAM. Your GPS >> location, and other parameters get saved in Flash, but the >> Oncore will require about 30-40 minutes to recover from a power >> outage before it can serve up time again. >> > Correction!!!!!! > > The battery backup charging current is on Pin 1 of the Oncore > receiver instead of Pin 3. Pin 3 is tied to ground, but Pin 1 has > a current limited 5V available. > > Tom > > Tom,
Thank you for this kind advice. I would have not thought of such a solution. I will order some of this part from Digi Key instead of persuing the battery solution. R - -- Ron Hahn, CISA, CISSP Rose Hill Rosslare Strand, Wexford, IRELAND -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (MingW32) Comment: Using GnuPG with Mozilla - http://www.enigmail.net/ iQEcBAEBAgAGBQJQgHAPAAoJEJMEFOwWFWJ1EhgH/2gdiCmDOWlwAjevGCeQ0E1a N98E/TXWPWFLUDAsO+kJrj9DECvkvIYScETPGHSe5OohcvAnpACHjs/hPzCLaJYh o2hva9IBsgN6ZhdTlQGKO3kDlgsYcwlzUK2cWq/aTBmDzPViFGjGK5585iTFtXVt ORqsUNAoVoafHFiFgIMIbOWqhbix2DxpvuMZRr0pzjGqZRaXdXNfhNwHt7uk5aWB Kk535McHG4mKE2oJtkACZJLwgSZHo0WbuxoGs+yIKEWms+owA/7G3kdRnLGE7Eh3 VkAgrVF9I3kD/FPEd+Z1IQQXZYXUfIU+l5k5dH5a51Jt0heTZIcppa6vrpSYTcs= =dlAK -----END PGP SIGNATURE----- _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions