On Mon, 15 Nov 2010 16:24:55 +1100, "Phil Allison"
wrote:

With a switcher, you're going to have a non-sinusodial current
waveform.

** Same for a transformer based PSU too.

True. Once you get away from a pure sine wave current waveform, the
phase angle method doesn't work. See the PG&E article I cited.

Therefore, you can't just use the phase angle as the power
factor and will need to measure the Apparent Power and the RMS powers.

** PF = true power / VA
No phase angles in sight ......

True. I just hate to agree with you, but I'll make an exception this
one time. But don't worry... it probably won't happen again.

Handy buzzword translator:
RMS power = True power
Apparent power = VA power.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558