> I did some experiments earlier today, and found that I need to have a
"total"
> system reaction time of at least one second or less to make on the fly AC
> voltage regulation worthwhile, 1/2 second would even be better.

That's about what I expected since heating elements don't change that fast,
but it's good to know for sure.  This gives you plenty of opportunity to do
some filtering of the feedback signal and still damp the PID controller well
to eliminate hunting or other instability.


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

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