How to build a "Golden-Cap" Circuit

[Gfast2]

Hi ESP-IDF,

The purpose of this Circuit is: Works like a PSU for ESP32 based system.

When the power failure are detected, all logging files in SD card / spiff partitions will be closed harmonically. Then the system will be send to deep sleep mode. The Golden-Gap should supply the power for ESP32 to deep-sleep as long as it need, in order to keep its very very precious on board time and possibly another bunch of parameters.

My Company has hade such kind of system. But I did not have the access to its design detail. But I figured out, if the Cap huge enough, it will make a Linux box be poweroff harmonically plus make its on board RTC keep running for really a while (many days). Which I believe a very awesome design.

Cheers

Gfast2