Don Lancaster wrote:
Floyd L. Davidson wrote:
Don Lancaster wrote:

DC, of course, cannot exist at all ever. Because it would have
to be unvarying through infinite time.
Boy, you are *pedantic*!
Can't we just define DC as current that doesn't vary "much"
for at last a "long" time. Granted that is ambiguous, but
what else would we the argue about, weather?


No.

Sum a 1 volt peak sinewave with a 0.6 volt dc term and you have
a waveform whose polarity continuously changes but whose average
value is continuous.

Hey, you moved *my* goal post! I said nothing about average
values. If it wiggles, it's AC. The difference is that
you are being so precise that you're saying if it wiggled since
the dawn of time, it's AC. I'm just saying that if it was so
long ago that I can't remember (which seems to be a pretty short
time anymore), that's long enough. :-)

Looking at the Fourier terms makes this waveform perfectly clear.
Calling it "AC" or "DC" does not.

"AC" or "DC" are gross and meaningless oversimplifications.

EXACTLY! And while you and I can make jokes about just how
pedantic we should be with definition of terms, the fact is that
anyone who actually thinks "AC" and "DC" are the determinative
definitions based on word meanings, is going to be wrong.

--
Floyd L. Davidson http://web.newsguy.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)