Hello,

Thanks to all of you for your response. Since I am trying to measure the output voltage of a UPS it could also be square or other forms apart from sine.

Since I will be measuring through 8 channels of the ADC,(that is, eight different voltages) and the conversion time of the micro will be around 300useconds, I wonder whether I will able to meet the minimum number of samples for each channels. (eg. 32 samples?)

Alfredo,
Can you give the details (if it is not proprietory) of the 89c51 based RMS measuring system you did?

Regards,
John.