The constants used in the power interpolation

onsar · 2020-07-11T11:10:03.969Z

I am interested in knowing more about the precision of the measurements that we are doing using the emonlibCM library but studying the code I cannot understand the constants used in the power interpolation. Specifically the variables:

y [i] = sin (phase_shift) / sin (sampleRate);
x [i] = cos (phase_shift) - y [i] * cos (sampleRate);

Can you help me with this part?

Best regards
Onsar

Robert.Wall · 2020-07-11T11:47:03.430Z

Look at the references that are given in the post from where library is downloaded.

EmonLibCM - Version 2.2.2 emonTx

EmonLibCM is a Continuous Monitoring alternative to EmonLib. Whereas emonLib repeats, every 5 or 10 s, a sequence of voltage and current measurements in each of the input channels for a short period, normally 200 ms, and then reports the measurements back to the sketch for onwards transmission to (for example) emonCMS; emonLibCM continuously measures in the background the voltage and all the current input channels in turn, calculates a true average quantity for each and then informs the sketch t…