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Re: 1600 watts magnetizing current?



Original poster: "Gerry Reynolds" <gerryreynolds-at-earthlink-dot-net> 

Hi Steve,

Another possibility, if the voltage and current waveforms can be captured
but a fourier analysis is either beyond the user, or equipment/sw is not
available, is to descretely sample the waveforms and compute the
instantaneous power for each descrete point over a cycle.  The instantaneous
power can then be averaged.  Likewise, the sampled waveforms can be used to
compute the RMS current and RMS voltage.  Accuracy will depend on how finely
the waveforms are sampled. The power factor will then be:

PF = Average Power/ (Vrms *Irms)

This might be within reach of more people?

Gerry R.

 > Original poster: "Steve Conner" <steve.conner-at-optosci-dot-com>
 >
 >  >How do you work out power factor when your
 >  >voltage and current are non sinuosidal(we have baad waveform distortion
 >  >here)?
 >
 >
 > You can also snapshot voltage and current with a 2-channel digital scope,
 > and do the calculations on a computer.
 >
 >
 > The basic idea is to do a Fourier analysis of the voltage and current
 > waveforms. This decomposes them into a combination of sine waves at 60,
120,
 > 180, 240 Hz etc. 60Hz is the "fundamental" and the rest are the
"harmonics".