S.O.S***MEASURE AC line voltage with 16c712 and compare with

[refo]

S.O.S
Hİ everybody;
i want to measure ac line voltage and compare this with my under and over adjust voltage when line voltage over or under to my fixed voltaj
its wait 1-20 second(time will be adjust) and will be open relays(its my thesis-İN UNİVERSİTY)
its my question:i want to use pic 16c7111 or 16c712 but i want to need knowladge how can i connect the pot to pic and and compare the line voltage ????
please HELP ME
Thanx to everybody who help me or suggest me their knowladgess

 

[Nigel Goodwin]

Re: S.O.S***MEASURE AC line voltage with 16c712 and compare

S.O.S
Hİ everybody;
i want to measure ac line voltage and compare this with my under and over adjust voltage when line voltage over or under to my fixed voltaj
its wait 1-20 second(time will be adjust) and will be open relays(its my thesis-İN UNİVERSİTY)
its my question:i want to use pic 16c7111 or 16c712 but i want to need knowladge how can i connect the pot to pic and and compare the line voltage ????
please HELP ME
Thanx to everybody who help me or suggest me their knowladgess

Presumably the 711 and 712 have analogue to digital converters in them? (I'm not familiar with those PIC's). If so, use a bridge rectifer to full wave rectify the mains and (using a potential divider) use the A2D to sample the rectified voltage.

Probably the easiest method is to measure the peak voltage (far easier than RMS), you could either detect zero crossing and delay quarter of a cycle to measure the peak voltage. Or you could sample for a certain time, and take the highest sample you find as peak.

 

[refo]

WHEN exceed VOLTAGE THE EDGE how can strart time

tnx man
but i need a answer when voltage is exceed the edge of which i fixed the voltage ,how can i start the time(1 to 20 second--its adjustable)


thanx to who help me or not...

 

[Nigel Goodwin]

Re: WHEN exceed VOLTAGE THE EDGE how can strart time

tnx man
but i need a answer when voltage is exceed the edge of which i fixed the voltage ,how can i start the time(1 to 20 second--its adjustable)


thanx to who help me or not...

Simply compare the voltage you measure with your required threashold voltage.

For timing you can use the number of mains cycles, mains is pretty stable at either 50 or 60Hz, depending where you are - simply count the number of zero crossing points, bearing in mind this will give you double the mains frequency. So at 50Hz, 20 seconds would be 2000 zero crossings.