monitoring circuit

[sarasvathi]

i need to build a transformerless 'monitoring circuit' to comparator of PIC12F675 from varying 220V AC. how to do this?

coz it has to detect 165VAC drop?

 

[Nigel Goodwin]

If you mean to detect the voltage change?, you simply need a potential divider (two resistors), just as a multimeter does. You also need to convert the AC to DC using a rectifer.