November 23, 2024, 07:50:31 AM

RTC module with super capacitor

Started by Patd93, November 19, 2014, 12:52:50 PM

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Patd93

I am currently working on a project which requires an RTC module to be run off a super capacitor rather than a battery for the olimex board. Is their a module out their on the market that would be suitable? Or could the RTC module provided by olimex be modified to include super capacitor. If yes, how?

Gerrit

#1
Looking at the schematic

https://www.olimex.com/Products/Modules/Time/MOD-RTC/resources/MOD-RTC-REV-A-SCHEMATIC.pdf

I would say replace the battery with your capacitor, and put a resistor in series with a low drop diode between the plus from the capacitor and pen 1 from UEXT connector to limit the current for loading, maybe 27 ohm would be a good value