only baffling to those who can't grasp the physics
physical reality
take the 2 sec windings
instead of line-coil-dot-n-coil-dot-line
do line-dot-coil-n-coil-dot-line
what is the line-line v in each case?
May I ask a question about the single vs two phase stuff
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only baffling to those who can't grasp the physics
physical reality
take the 2 sec windings
instead of line-coil-dot-n-coil-dot-line
do line-dot-coil-n-coil-dot-line
what is the line-line v in each case?
LarryFine
Master Electrician Electric Contractor Richmond VA
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But, at any given moment within a sine wave (other than 0 of course), it is applicable, at least moreso than calling it a time delay of half a cycle.
Um..
If I connect my Fluke meter to 120Vac will it read any differently if I reverse the leads?
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ggunn
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Nope, of course not. I was replying to the assertion that earth is the reference.
ggunn
PE (Electrical), NABCEP certified
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I knew this would be raised.
Yes, if you picked any single moment in time.
You can't define a sine wave by a measurement of single point instantaneous values.
ggunn
PE (Electrical), NABCEP certified
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I do not think that failure to grasp the physics is the basis of this discussion. The argument isn't over what is happening, it's over what to call it.
ggunn
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jumper
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I am answering the question, but not speaking to you. You know the following.
From an earlier posted link:
“The Center-tap Transformer
center tap transformer
Above shows a typical center-tap transformer. The tapping point is in the exact center of the secondary winding providing a common connection for two equal but opposite secondary voltages. With the center-tap grounded, the output VA will be positive in nature with respect to the ground, while the voltage at the other secondary, VB will be negative and opposite in nature, that is they are 180o electrical degrees out-of-phase with each other.
However, there is one disadvantage of using an ungrounded center tapped transformer and that is it can produce unbalanced voltages in the two secondary windings due to unsymmetrical currents flowing in the common third connection because of unbalanced loads.
We can also produce a center-tap transformer using the dual voltage transformer from above. By connecting the secondary windings in series, we can use the center link as the tap as shown. If the output from each secondary is V, the total output voltage for the secondary winding will be equal to 2V as shown.
Center-tap Transformer using a Dual Voltage Transformer
Transformer
dual voltage center tap
Multiple Winding Transformers have many uses in electrical and electronic circuits. They can be used to supply different secondary voltages to different loads. Have their windings connected together in series or parallel combinations to provide higher voltages or currents, or have their secondary windings connected together in series to produce a center tapped transformer.”
https://www.electronics-tutorials.ws/transformer/multiple-winding-transformers.html
LarryFine
Master Electrician Electric Contractor Richmond VA
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Well, duh! :roll: That's the whole reason for threads like this. :happyyes:
I agree that 180 degrees is appropriate in the opposing sense, like the two points where a diameter meets its circle, because it's applicable in the instantaneous moment, whereas 180 degrees along a sine wave, such as peak-to-peak, is only applicable over the duration of half a cycle (or more).
Absolutely.
LarryFine
Master Electrician Electric Contractor Richmond VA
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- Henrico County, VA
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- Electrical Contractor
If you place the ground probe on the dot on both (or neither) windings, you'll definitely see two in-phase traces.
No, the reversal IS the cause of the phase angle difference.
:happyno:
the phase angle difference is what allows one to be 'positive' and the other 'negative'
if in phase their polarities would always match
LarryFine
Master Electrician Electric Contractor Richmond VA
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- Henrico County, VA
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Which means that it's the "way you hook up two of them" that is what accounts for the difference.
I am answering the question, but not speaking to you. You know the following.
From an earlier posted link:
“The Center-tap Transformer
center tap transformer
Above shows a typical center-tap transformer. The tapping point is in the exact center of the secondary winding providing a common connection for two equal but opposite secondary voltages. With the center-tap grounded, the output VA will be positive in nature with respect to the ground, while the voltage at the other secondary, VB will be negative and opposite in nature, that is they are 180o electrical degrees out-of-phase with each other.
However, there is one disadvantage of using an ungrounded center tapped transformer and that is it can produce unbalanced voltages in the two secondary windings due to unsymmetrical currents flowing in the common third connection because of unbalanced loads.
We can also produce a center-tap transformer using the dual voltage transformer from above. By connecting the secondary windings in series, we can use the center link as the tap as shown. If the output from each secondary is V, the total output voltage for the secondary winding will be equal to 2V as shown.
Center-tap Transformer using a Dual Voltage Transformer
Transformer
dual voltage center tap
Multiple Winding Transformers have many uses in electrical and electronic circuits. They can be used to supply different secondary voltages to different loads. Have their windings connected together in series or parallel combinations to provide higher voltages or currents, or have their secondary windings connected together in series to produce a center tapped transformer.”
https://www.electronics-tutorials.ws/transformer/multiple-winding-transformers.html
:happyyes:
180 electrical degrees out of phase
they actually show the waveforms out of phase
LarryFine
Master Electrician Electric Contractor Richmond VA
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- Henrico County, VA
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- Electrical Contractor
No, it ain't. The flipping of the lead "polarity" when reading the two sources is.
Because it literally is, but electrically connected additively, which requires being connected in phase. Two windings electrically connected subtractively would be out of phase. See above.
LarryFine
Master Electrician Electric Contractor Richmond VA
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- Henrico County, VA
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- Electrical Contractor
(I do, too, but don't tell anyone!)
:happysad:
nope
one dot is common
the other a line
hence out of phase
both lines = in phase = 0 v
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