Hello,
Just as the topic implies, it came in my mind the need of making this project.I need to find any existing material[Circuit Schematic,theory...etc] regarding this project if it is present. I think that this not a difficult one for beginners like me.
Project Requirements :
1. Display of duration for which the mains supply has been down.
2. Auto Off display when mains supply is restored.
on good way to solve this is to use some digital device
--- when you power is down where from you are getting the power for the counter circuit. is there any battery i can tell you a circuit which will give you a pulse
when mains is out counting the duration of the pulse you can track the record of MAINSOUT Time
Use a power down detect as interrupt to the micro. Now in micro use that as to note down the time from RTC (powered from the battery) and as soon as the next power up u will receive the RESET and u can gain look up at the RTC time . and difference is wt u need.