Backup Power Supply

Hallo People!

I Search for a good Pic controlled Backup Power Supply schematic.
I need for a Alarm Device that I have made,when the Main Supply is no more here I need that the circuit switch to 12 Volt Acid Lead,and all the Time be Charged when the Main Supply come back.
I hope You understand what I mean.

Thanks a lot.

Regards Pesti.

Hi. Why a microcontroller? With a comparator and a few components can solve this problem.
It's very easy and cheaper

Thanks,
did you have any schematics or links for me.

Thanks a lot

Regards Pesti

Hello,

Goto www.microchip.com and get AN714. That's an application note on a security system and there are schematics for an alarm system including the power supply. Well designed!


HTH,

BobK

Thank you !

Regards Pesti.