May I ask a question about the single vs two phase stuff

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jumper

jumper

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Ingenieur said:
I think I see what he is saying, the load polarities should be reversed
kinda iffy, it could go either way
he thinks the load neg should be on the system common/ground

my way, at load
v = -v
i =+i since flow is - to +
p = +v x -i = -vi
negative to me implies load is absorbing power
positive would be supplying
???
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Gotta think about that. Will later, these - and + signs get screwy at times depending on our reference. As long as you both are obeying KVL, I am good. You both say loop gotta sum to 0.:thumbsup:
 
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gar

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EE
180703-1721 EDT

jumper:

The simple way to look at the one loop circuit is to consider a battery and a load resistor.

Call the negative end of the battery the reference point. Connect the minus probe of your meter to the reference (negative end of battery).

Connect the red probe to the battery + terminal. You will read a + voltage.

Go to the end of the resistor connected to the battery +, and you will read the same + voltage as at the battery +.

Take the red probe and read the voltage at the other end of the load resistor and you will read 0 V. That is the sum of the voltages around a closed loop is zero.

.
 
jumper

jumper

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gar said:
180703-1721 EDT

jumper:

The simple way to look at the one loop circuit is to consider a battery and a load resistor.

Call the negative end of the battery the reference point. Connect the minus probe of your meter to the reference (negative end of battery).

Connect the red probe to the battery + terminal. You will read a + voltage.

Go to the end of the resistor connected to the battery +, and you will read the same + voltage as at the battery +.

Take the red probe and read the voltage at the other end of the load resistor and you will read 0 V. That is the sum of the voltages around a closed loop is zero.

.
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Gar, I get it. Much easier to just do the math. I know Mr Kirchhoff.
 
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GoldDigger

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Ingenieur said:
it's not valid
observing convention and for power to flow
v rise on source
v drop on load
i - to + on source and load
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To me those three statements of convention are incompatible (unless you somehow can reconcile a positive current through both source and load leading to the point labelled - on the load being at at more positive voltage than the point labelled +.)
If you are just using the + and - signs to identify scope probes or to identify current direction, then it is consistent, but very confusing to most folks.
 
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Ingenieur

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GoldDigger said:
To me those three statements of convention are incompatible (unless you somehow can reconcile a positive current through both source and load leading to the point labelled - on the load being at at more positive voltage than the point labelled +.)
If you are just using the + and - signs to identify scope probes or to identify current direction, then it is consistent, but very confusing to most folks.
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not confusing to me
but in general I do not label loads
or even sources in ac ckts
 
jumper

jumper

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Ingenieur said:
not sure it matters much as long as the source is correct and you are consistent
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GoldDigger said:
If you are just using the + and - signs to identify scope probes or to identify current direction, then it is consistent, but very confusing to most folks.
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Key word is consistent. And understanding the perspective and context of what the person is presenting. I can follow Iggy fine once he gave his reference. Gar also after I closely read what he saying and why.
 
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ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
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Consulting Electrical Engineer - Photovoltaic Systems
jumper said:
“The horror! The horror!”

Joseph Conrad’s “Heart of Darkness.”
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"No one gwine gotta be a slave all de time no mo." - Firesign Theatre, "Ralph Spoilsport Motors"
 
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jaggedben

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Solar and Energy Storage Installer
Okay, let's get back on track... :D

jumper said:
Yep.

And the darn terminology. And reading graphs out of context. And using non standard terms out of context. And using reference points for the scope as actual polarity of an AC signal. And using terms like additive for the secondary windings instead of series and parallel, additive and subtractive are used for polarity test of the primary and secondary! And saying center tap secondary when it is not! It is a multiwinding secondary! And split phase, anti phase, or two hemi phases are not NEC or IEEE defined systems. It is Single Phase!

And...I need to chill...

I feel better now.:)
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Do 'phase' and 'in-phase' and 'out of phase' have a sufficiently defined, agreed upon, industry standard meaning that could be deployed to characterize the 120/240 volt system? Or are they just another example of vague or misused terminology?

I submit that I'm unaware of any such definition.

Specifically, I'm unaware of such a definition that precludes two waveforms with the same zero-crossings from being 'in-phase.' Not saying (yet?) that it should or shouldn't preclude such, just that I haven't seen the definition.
 
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I

Ingenieur

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Location
Earth
jaggedben said:
Okay, let's get back on track... :D



Do 'phase' and 'in-phase' and 'out of phase' have a sufficiently defined, agreed upon, industry standard meaning that could be deployed to characterize the 120/240 volt system?

I submit that I'm unaware of any such definition.

Specifically, I'm unaware of such a definition that precludes two waveforms with the same zero-crossings from being 'in-phase.' Not saying (yet?) That it should or shouldn't preclude such, just that I haven't seen the definition.
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not as much an industry term as it is a math or EE term/description
I have a few books at work
std handbook for EE's
EE dictionary
 
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