So - how many phases?

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So - how many phases?

  • 1

    Votes: 25 89.3%

  • 2

    Votes: 0 0.0%

  • Other - and I'll explain why

    Votes: 3 10.7%
  • Total voters
    28
  • Poll closed .
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rbalex

rbalex

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I have deliberately avoided graphics over on the ?other? thread because I wanted to discuss what a phase is rather than what it may look like or how it?s measured.

That said, how many phases does this simple two winding transformer have. Whether it has a practical application is irrelevant ? just how many phases? (I also deliberately left off a neutral :D)

Edit add (with thanks to mivey): Assume the applied primary voltage is characterized by the general function V(t)= A sin(ωt+φ0), where A, ω and φ0are constants. Apply any arbitrary set of turns ratios you desire between the primary winding and secondary taps. (With judicious selection you might even make one a neutral.)

XFMR.jpg
 
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rbalex said:
I have deliberately avoided graphics over on the ?other? thread because I wanted to discuss what a phase is rather than what it may look like or how it?s measured.

That said, how many phases does this simple two winding transformer have. Whether it has a practical application is irrelevant ? just how many phases? (I also deliberately left off a neutral :D)


View attachment 6455
Click to expand...

THANK YOU!!!!

I was going to post a similar drawing with the same question on the "other" thread.

My vote is one phase. Even if you didn't leave off a neutral.
 
One, but couldn't you ground any of the points? (A-F) That would still leave you with one phase though. I really don't want to get into the other drawn out argument...
 
Zero

Zero

rbalex said:
That said, how many phases does this simple two winding transformer have.
Click to expand...
Seeing no definitions, I'll use the technically correct definition of phase that says the phase of an AC wave is any point on the AC wave. The phase is usually indicated by the number of degrees from a reference point. With polyphase voltages or currents, there is more than one phase at any given instant. Two-wire circuits can only be single-phase as there can only be one phase present at any given instant.

In considering your diagram, I see no waveforms specified so you have zero phases.

If you want to know what to call this device: it is a single-phase transformer.
 
Am I close?:D

moon-phases-diagram.gif
 
I say single phase, and there is no neutral. You can ground any one of the taps if you wish but that does not make it a neutral. Add one more tap or take one away and the center tap is the neutral - or as neutral as you are going to get.

Wait till the guys from other thread put their 50,000,000? in and we will have 900 posts:thumbsdown:
 
kwired said:
I say single phase, and there is no neutral. You can ground any one of the taps if you wish but that does not make it a neutral. Add one more tap or take one away and the center tap is the neutral - or as neutral as you are going to get.

Wait till the guys from other thread put their 50,000,000? in and we will have 900 posts:thumbsdown:
Click to expand...

That thread has averaged 48.7 posts per day for 17 days, a total of 828 posts. Amazing.
 
mivey said:
Seeing no definitions, I'll use the technically correct definition of phase that says the phase of an AC wave is any point on the AC wave. The phase is usually indicated by the number of degrees from a reference point. With polyphase voltages or currents, there is more than one phase at any given instant. Two-wire circuits can only be single-phase as there can only be one phase present at any given instant.

In considering your diagram, I see no waveforms specified so you have zero phases.

If you want to know what to call this device: it is a single-phase transformer.
Click to expand...
Good points.

Assume the applied primary voltage is characterized by the general function V(t)= A sin(ωt+φ0), where A, ω and φ0are constants. Apply any arbitrary set of turns ratios you desire between the primary winding and secondary taps.

We agree on what to call the device (YEA). Not sure we agree on why yet - but we seem to be getting there.
 
rbalex said:
Do we have oscilloscopes capable of 28 day scanning periods?
Click to expand...
It's called a phase thread on this forum.


One. This is a single-phase voltage divider with multiple taps.
-- though --
Pragmatically around 30 with the given taps. You can create usable (sub)phases from AB, AC, AD, AE, etc. They're not properly separate phases but only sections of the whole that can be used as though they were separate.
 
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