I have several 5V Oncore UT+ receivers of the type that did not include a rechargeable on-board battery, but didn't want to bother with lithium primary batteries or rechargeable batteries and their associated holders so I opted to use supercapacitors. Specifically, I use the Panasonic EEC-F5R5U105 supercap with a capacitance of 1F and a max voltage rating of 5.5V.
Charging is easy: I simply run 5V power through a diode and a resistor sized to prevent exceeding the diode's current limit and the capacitor charges in about 20-30 minutes. The diode prevents the supercap from discharging through the resistor when the power fails. I use a 1N4148 small signal diode rather than a 1N400x-series diode because the 1N4148 has a smaller reverse leakage current. A 240 ohm resistor keeps the peak current to 20mA (the diode can handle up to 200mA forward current) and the capacitor is charged up in about 20 minutes after power-on. Adjust the values for your specific needs. Once charged, it maintains the Oncore's RAM for several weeks with no power. On Mon, Apr 25, 2016 at 12:25 PM, Azelio Boriani <azelio.bori...@gmail.com> wrote: > Panasonic ML621 or equivalent. Alternatively you can use the battery > pin (pin 6): remove the onboard battery and use en external primary > cell (CR2032 or equivalent). See pages 15 to 21 of the M12M user > manual. > <http://www.ilotus.com.sg/~ilotus/sites/all/themes/zeropoint/pdf/m12m/M12M%20-%20User%20Guide%20%28Ver%201.0.0%29.pdf> > > On Mon, Apr 25, 2016 at 2:11 AM, Joseph Gray <jg...@zianet.com> wrote: >> Can anyone recommend a rechargeable lithium coin cell that is a direct >> replacement for the ones that come on some Oncore receivers? Something >> I can order from Mouser or Digikey, if possible. >> >> Joe Gray >> W5JG >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. -- Pete Stephenson _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.