On Wednesday, September 11, 2019 at 3:28:12 PM UTC-4, Mike Oxbern wrote:
On 9/11/2019 2:12 PM, trader_4 wrote:
On Wednesday, September 11, 2019 at 1:34:19 PM UTC-4, wrote:
On Tue, 10 Sep 2019 17:39:01 -0700 (PDT), trader_4
wrote:

On Tuesday, September 10, 2019 at 8:16:05 PM UTC-4, wrote:
On Tue, 10 Sep 2019 09:05:05 -0700 (PDT), trader_4
wrote:

On Tuesday, September 10, 2019 at 11:56:17 AM UTC-4, wrote:
On Tue, 10 Sep 2019 06:40:50 -0700 (PDT), trader_4
wrote:

An IEEE fellow, professor
of electrical engineering,
I am talking about people in the trade, not some professor who has
never touched a piece of wire.
Terms have meanings. When you have to blur the nomenclature to get
novices to understand you corrupt the meaning of the term.
In other words, you can't handle the most basic electrical engineering
principles that show electrically what that service is. It's likeOh, p
denying that tissues are actually a soft paper product made from
trees and insisting that they are just Kleenex, that's all they are,
that's all they ever can be, because that's how they are commonly
referred to.


No people in the trade where there is life on the line use very
specific terms. Blurring them to make concepts understandable for new
students or homeowners is not what they choose to do.
Oh, please stop with the "life on the line' nonsense, like a discussion
about phase is going to kill people. And how about
answering the very simple questions I posed to Ralph:



Let's take your second example of what you
say was the old two phase power, ie 90 deg phase difference, three wires with
a common return. I changed the phase difference to 70 deg by rotating
one of the windings on the generator. Are there
still two phases there? Now I change it to 179 deg, are there still
two phases there? I change it to 181, are there still two phases there?
I change it to 180 deg, are there still two phases
there? And how is the latter any electrically different than the
3 wire 240/120V service going into a home? Describe how I could tell
from the panel in your house which of the two power sources I had
supplying it, 240/120 from pole a transformer or two phase from
Ralph's generator that I changed to 180 deg phase shift. How are
they electrically different, how do they behave differently?

You keep playing these theoretical games with weird phase angles but
the fact is the phases are going to be symmetrical in an alternator.
That can be 120 out or 90 out but each one will be the same.
Say what? In Ralph's two phase example from 100 years ago, there
are two phases, one 90 deg off from the other. Nothing symmetric
about that. If there are 3 phases, 0, 120, 240, that is symmetric.
There is no reqt that phases have to be symmetric to be phases.

And the reason I bring up those "weird" phase angles, is to try
to get you to see that 90 deg two phase isn't something unique,
it isn't something that defines two phase forever. If you rotate
the one winding ten more degrees, you'd have 100 deg phase difference.
Are there still two phases there? And when you rotate it to 180,
bring it into a house at 120V on 3 wires, then what you have is
electrically identical to split-phase from a transformer. You
have two 120V AC sources, 180 out of phase with each other.
You can't tell them apart.






180 out
is simply single phase, a straight line if you remember your geometry
I am not doing this anymore.
Is it only one phase when Ralph's two phase alternator is at 90 deg,
100 deg or 179 deg phase difference? How about at 181? 270?
If you want to exclude 180 then it would have to be by definition, otherwise
it's just as valid a phase as any of the others. Excluding it would
seem rather odd, because then Ralph's alternator would have 120V
coming out of one winding, 120v with 180 deg phase difference
coming out of the other winding, so if the second one isn't a phase
what would you call it?


Here are two plots, one at 0 and one at 180 degrees.

Looks like single phase with the second plot having reversed leads.Â* Looks electrically useless to me.

http://fooplot.com/#W3sidHlwZSI6MCwi...lwZSI6MTAwMH1d

Would you like to buy a special dual-polarity AA battery?

It's not electrically useless, it's how 240/120 is delivered to your
house on 3 wires. And your graph sure shows two phases, separated by
180 deg. How would you describe that, if not two sine waves, one
180 deg out of phase with the other?