Quote Originally Posted by Darrel Taylor View Post
If you'll be primarily measuring motor currents, the wave forms will NOT be sine, and .707 will not even come close. In that case, there is only one way to go.

Run the signal from the current sensor into an R-M-S converter. Don't bother trying to do it in software. I like the LTC1966, but it's a really tiny chip and isn't great for hobby use cause they're too hard to solder.

There are several other chips available that do the same thing. But for sure you will need an R-M-S (Root Mean Square) reading for any inductive loads.
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You can also take many readings (~100 x the frequency or 6000Hz) and average them but I don't think a PIC can do this fast enough for accuracy. This is how digital wattmeters work.

If an oscilloscope is not available, it might be possible to get an idea of the waveform using a PC or laptop with a LineIn port for the soundcard. The sampling rate should be adequate unless there are sharp spikes. Since the Allegro output is 0-5V, you can use the same technique I use for IR & RF. See...