On Mon, 30 Jul 2018 16:03:01 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 5:24:46 PM UTC-4, Uniphase wrote:
On 7/30/2018 4:06 PM, tarder_4 wrote:
If yes, then how about if the phase angle was changed to 179 deg, or
181 deg, would there still be two phases there?

How about 180 deg? Two phases, yes or no?

And if it's suddenly no, then why?


Lets analyze the circuit.

Ignoring the voltage/current zero crossings and assuming a pure resistive load,

at any time t, the current on the secondary winding is either flowing from end L1 toward end L2 or end L2 toward end L1.

Also, at that same time t, the voltage is either rising or falling at all points along the entire length of the wire at the same rate.

The rise and fall of the voltage at L1 and L2 are in sync, obviously because there is only one phase on the single continuous piece of wire that forms the secondary coil.

The rise and fall on the secondary coil is in sync with the rise and fall on the primary coil.Â* Since the primary coil is single phase, so is the secondary.

Clearly single phase, anything else is a parlor trick.

Sure, but what happens when you center tap the secondary? You now have
essentially two windings that are connected together, creating two 120V
voltage sources that are of opposite polarity, which with a periodic
waveform is what? ..... 180 deg phase difference. That's how you get 240/120
over a shared neutral. You have two 120V sources that are 180 deg out
of phase.

The current flow in those 2 secondaries is still flowing in the same
direction, at the same time.
Kirchoff's law says that.
They did not change phase. You just changed the place where you were
looking at them.
Again, look at a sine wave and lay it over both windings. The 0 point
will be at the center tap. One side will be up and one side down at
any given instant. It is still just one sine wave and just one phase.

In "N-phase" it will be required to have "N" different sine waves but
that is just a red herring in this discussion because we just have 1,
2 and 3. In each of those there is a sine wave displaced by 90 or 120
degrees.