On Tue, 15 Apr 2014 23:01:32 -0500, Martin Eastburn
wrote:

You got it wrong. it is this : Power (measured in the watt) - Voltage
(measured in the Volt) Times Current(measured in Amps) Times Cos(phase
angle) (1 to 0 in value).

No, I certainly don't. That formula only for SINE WAVES (i.e. no
harmonics on either current or voltage waveforms). OTOH, PF=W/VA
*always* works.

P = V*I*Cos(theta). When in DC Cos(0)=1. V is DC voltage in that case.

So? Again, sine waves are the trivial case. That formula doesn't
work for nonlinear situations. The DC case is more than trivial. PF
is meaningless.

When in DC - it becomes : P = E*I where E is the DC voltage. I is the
DC current and there isn't a phase angle or Theta is Zero and COS(0) = 1.

Trivial cases are irrelevant. Not sure why you insist on lecturing on
the trivial.

A Watt is the unit of power. Not the plural form.

Plural is plural. Two times a watt is two watts. ...and if you really
want to get pedantic about the language, "watt" is not capitalized.
Proper names, when used as names of units are *not* capitalized.
Abbreviations for proper names are.

Correct Incorrect
W, V, A w, v, a
watt Watt
volt Volt
ampere Ampere
meter Meter
m M

When V is used it is AC. When V is used I is AC.

Whatever that means.

They are in R.M.S. scaling. Root of the Mean Square.

May be. That's the point, though. Your assumptions only work for
sine waves and the conversion between Peak, RMS, whatever, is trivial,
in that case. RMS is the voltage (or current) of a waveform that will
give the equivalent power of a DC value. It's one of many meaningful
numbers. The root of the mean square (for voltage or current) can be
calculated, as can the average of the voltage X current (power).

No periods in RMS.

(A.C. volt meters and current transforms 'translate to these'.)

Again, "translate to" means "only valid for sine waves". If you
aren't dealing with sine waves, these "translations" are meaningless.
Worse, actually. They're wrong. A "true RMS" meter is always right
(within it's physical capabilities).

Some times special voltages are used as design needs.

Was that supposed to mean something?

Harmonics from inductive and capacitive circuits are very small
compared to the main current / voltage waveform. They are ignored
if anything normal.

Oh, good grief! Stop with the word salad, already. Harmonics from
inductors and capacitors are ZERO. They're linear devices. Switching
elements (semiconductors) are a whole different kettle, as is the real
world.

One should always use the phase angle in the AC model. Meters do.

Wrong. Meters certainly do not. They integrate V, A, V*A, or measure
heat.

So the task for the technician is just measure it using a quality meter.

No, one should always use reality. It may be impossible to measure
phase angle. It's always possible to measure V, I, and P. PF can then
be derived from that, if necessary.

Even a reasonable multi-meter from Radio-Shack can measure Correctly
(enough). I like three or four major makers and for the lab I use two.

If they're "true RMS" meters, they're integrating type. If they're
peak or average (rectified) meters, then they're calibrated assuming a
sine wave. If you have something else (harmonics) then they're wrong.


V means AC voltage. E means DC voltage. I is the current that
matches. Cosine(phase-angle) is Always used in AC.

Now you making stuff up. Wrong.

One should design for several times that of V*A*Cos(0).

Whatever that means.

Martin - Senior Scientist and former Technologist serving between and
working for both Intel and the Schlumberger.
I'm working on my computer I built in the late 50's and early 60's. It
has just under a thousand gates. All hand wired.

Don't break your arm.