Concerning the RTC on the GM862-GPRS; it is about 18 hours a day the main
power is not available. Can we use a cheap circuitry?
they can use a backup capacitor of 0,47F. It works up to -25 degrees.
You can find on the web sites:
The regulator have to be isolated from module+backup capacitor during
It can be done with a mosfet that they have to disable with the module
For the mosfet you can visit the web site:
The mosfet have to lead when the regulator is switched-on and have to be
interdict when the regulator is switched-off.