auto recloser ELCB

[mister_e]

I guess it would depend of your definition of "when there's a signal". You could even skip the PIC and use a voltage comparator (easy to modify your current circuit)... or use the PIC with a voltage comparator interrupt, OR use an ADC reading then process it with a Timer interrupt.

[badbaik]

if i use voltage comparator, i can skip use PIC?...so, how can i make a timer or counter in voltage cmprator ? what kind of voltage comparator? can you give 1 example?

[mister_e]

Depending the delay you need too... a simple 555, or whatever else monostable circuit, spring to mind. \

There's also another point of view... use a PIC with a voltage comparator (or op-amp) built-in.