> However there is no such thing as negative power so any negative output
> from the multiplier needs to be thrown away before adding (it is the
> reflected or reactive power).

Negative power in this context is perfectly valid because it means the load
is producing, as opposed to sinking, power.  This is normal for capacitive
or inductive loads over part of the power cycle.  The positive and negative
values need to all be considered when computing the average power consumed
by the load.  You do not want to throw away the negative power readings.


********************************************************************
Olin Lathrop, embedded systems consultant in Littleton Massachusetts
(978) 742-9014, olin@embedinc.com, http://www.embedinc.com

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