can i connect ADC or microcontroller ground pin to mains neutral?

[kubeek]

Thanks northguy, I got the idea that shaha tried all of the combinations and it stil dosen´t work, but you may as well be right that i wasn´t clear enough.

p.s.: do these apostrophes look that bad, or is it just me getting more and more used to the vertical english ones? does this bother anyone and compromise the legibility?

 

[shaha20111]

Thanks Northguy, i did as u said, its showing +ve voltage but the results r coming wrong. its not showing results as per the calculation.

 

[shaha20111]

friends finally problem solved.. i connected opamp at the output of AD633, and converted -ve voltage into positive, here is the schematic connected at the output of AD633

 

[shaha20111]

Thanks to all...

 

[shaha20111]

thanks friends

 

[NorthGuy]

Thanks Northguy, i did as u said, its showing +ve voltage but the results r coming wrong. its not showing results as per the calculation.

This would mean that it is not symmetrical, that is your ground is not at 0. If you calibrate in certain conditions, such as pf=1, it may show correct results in these conditions, but if you go to pf=0.5 the result will no longer be correct.

 

[Nagygedo]

i have this wattmeter circuitView attachment 84822
it is directly powered by mains and neutral lines via 15V zener diodes, pin 7 is the output pin, this circuit can sense up to 2200W of power. now my question is, i want to connect the pin 7(output pin) to ADC input, and ADC output to the 8051 microcontroller, but my problem is that where to connect the ADC ground pin and microcontroller ground pin?? can i connect it directly to the neutral line?? please friends help me in this circuit.

i have this wattmeter circuitView attachment 84822
it is directly powered by mains and neutral lines via 15V zener diodes, pin 7 is the output pin, this circuit can sense up to 2200W of power. now my question is, i want to connect the pin 7(output pin) to ADC input, and ADC output to the 8051 microcontroller, but my problem is that where to connect the ADC ground pin and microcontroller ground pin?? can i connect it directly to the neutral line?? please friends help me in this circuit.

 

[Nagygedo]

please i want to know what changes will be added to this circut if i want it to meaure devices more than 2200 watt that can reach to 5000 watt ??

 

[alec_t]

I presume you mean the post #11 circuit with the modifications described? If so, it may only be necessary to change the current transformer's burden resistor value.
BTW, you have resurrected and hijacked a year-old thread. Bad practice. Better to start your own threads if you want replies.