Question about inductance and capacitance

[icidasset]

Hi energetic forum,

I'm trying to make a summary of all the general formula used in electric engineering,
but I keep getting stuck with inductance and capacitance.

Eric Dollard gives capacitance as: C = Phi / e

So what do we need then to calculate or measure Phi and e?
Do we use the formula given by Steinmetz for Phi and Psi?
Namely:



and



Which I then refactored to:



and



And what about 'e'? Is this the impressed voltage we can read from the voltmeter?
Or do we use the formula 'Psi / t' for this?

Also, Steinmetz gives entirely different formula for inductance and capacitance.
For example, this one for capacitance:



I'm confused...

[wayne.ct]

May I add to your confusion?

Your comments confuse me. So, on that basis, allow me to say, a little confusion is a common state of mind. My comment may help, or not.

I think you would be well advised to be very careful that you understand each of the elements of the formula that you document in the particular way in which the author or user of that formula is using the term. The way that particular words are used today and the way the same words were used 100 years ago are not the same. Even a word like length can have subtle differences as used now and then. For example, would you say the distance between the two "plates" of a "theoretically ideal" capacitor is a "length"? Yet, that is sometimes the way the word "length" has been used in the past. The "length" in the last equation, i.e. (20) looks like a case in point.

The same goes for the word "capacity". Are we talking about the current carrying "capacity" of a wire? Or, the electro potential storage "capacity" of a capacitor?

Hopefully these few comments will be a help.

[upgradd]

Notation Confusion

Basically your confusion is about two things:

1) Specific notation:

For example, the Greek or Latin characters used to denote any one quantity, relation, or constant. This is a major obstacle for people who are new to the subject, which you appear to be. If you already know the physical relations and what the formulas are for, differences in notation don't really confuse you but they may certainly annoy you if they aren't your preferred choice. Dollard falls into this last part for almost everyone who reads his work: it's annoying to see obsolete notation.

2) The relationship of each equation:

Some of the equations you've posted are for demonstrating different aspects of the same thing. Such as how can you MEASURE an existing capacitance by using things you already have, such as a voltmeter, ammeter or coulomb meter (an electrometer comprises all of these). Or how can you CALCULATE the capacitance of a physical object by knowing the properties of the insulating materials and the area and dimensions of the conductors.

So putting it all together, don't get hung up on notation, it's entirely arbitrary as to what symbol you use for xyz quantity or constant. Just focus on understanding the physical relations which the author is trying to convey. For example, capacitance of any linear capacitor is proportional to the quotient of the charge stored divided by the potential difference between the plates (C = Q/V). OR capacitance of two flat parallel plates (neglecting fringing fields) is proportional to the area of one plate times the permittivity of the space between the plates and inversely proportional to the distance of separation (C = (e_r*A)/d).

Ultimately Dollard's formulas are impractical as they don't relate to specific geometries or physical conditions: he just gives you the basic physical model that can then, with advanced math (usually calculus), be used to derive a relation that will help you calculate your specific problem.

For example, a 10ft long 12AWG wire isolated in free-space has a definite capacitance but it cannot be determined using the parallel plate formula given earlier. Using advanced methods we can actually calculate its value (which I won't get into). This is an important type of capacitance that affects the properties of radio antennae and is called the ISOTROPIC capacitance of the wire. (Isotropic meaning the capacitance is the same in all directions.)

To conclude, only examine Dollard's work as a "primer" on the physical relations. DO NOT take them to be "gospel," as they can't be used for normal things that you have on your desk, such as a toroidal coil or a vertical wire. The basic idea that something is proportional to some other stuff is what you need to focus on understanding, and then always remember that it's a "first principle" thing that must be modified for your application.

Try getting a book on trigonometry (McKeague 7th ed.) and after you've mastered the identities and functions, move on to calculus (Stewart early transcendentals 7th ed) and THEN go deeper into either physics or electrical engineering. You have to have a strong math back ground (that's beyond everyday algebra) to comprehend why there are many different formulas for calculating the same things. Without a solid foundation in advanced math you will only remain lost and confused.

[icidasset]

Your comments confuse me. So, on that basis, allow me to say, a little confusion is a common state of mind. My comment may help, or not.

I think you would be well advised to be very careful that you understand each of the elements of the formula that you document in the particular way in which the author or user of that formula is using the term. The way that particular words are used today and the way the same words were used 100 years ago are not the same. Even a word like length can have subtle differences as used now and then. For example, would you say the distance between the two "plates" of a "theoretically ideal" capacitor is a "length"? Yet, that is sometimes the way the word "length" has been used in the past. The "length" in the last equation, i.e. (20) looks like a case in point.

The same goes for the word "capacity". Are we talking about the current carrying "capacity" of a wire? Or, the electro potential storage "capacity" of a capacitor?

Hopefully these few comments will be a help.

@wayne.ct Thanks for your comment, it is helpful, I'll definitely keep this in mind. I always presumed that 'capacity' was the coefficient for dielectric storage, and only that. I must say, I'm having a hard time with all the different terms and how everyone uses them slightly different. Like current and voltage...

Basically your confusion is about two things:

1) Specific notation:

For example, the Greek or Latin characters used to denote any one quantity, relation, or constant. This is a major obstacle for people who are new to the subject, which you appear to be. If you already know the physical relations and what the formulas are for, differences in notation don't really confuse you but they may certainly annoy you if they aren't your preferred choice. Dollard falls into this last part for almost everyone who reads his work: it's annoying to see obsolete notation.

2) The relationship of each equation:

Some of the equations you've posted are for demonstrating different aspects of the same thing. Such as how can you MEASURE an existing capacitance by using things you already have, such as a voltmeter, ammeter or coulomb meter (an electrometer comprises all of these). Or how can you CALCULATE the capacitance of a physical object by knowing the properties of the insulating materials and the area and dimensions of the conductors.

So putting it all together, don't get hung up on notation, it's entirely arbitrary as to what symbol you use for xyz quantity or constant. Just focus on understanding the physical relations which the author is trying to convey. For example, capacitance of any linear capacitor is proportional to the quotient of the charge stored divided by the potential difference between the plates (C = Q/V). OR capacitance of two flat parallel plates (neglecting fringing fields) is proportional to the area of one plate times the permittivity of the space between the plates and inversely proportional to the distance of separation (C = (e_r*A)/d).

Ultimately Dollard's formulas are impractical as they don't relate to specific geometries or physical conditions: he just gives you the basic physical model that can then, with advanced math (usually calculus), be used to derive a relation that will help you calculate your specific problem.

For example, a 10ft long 12AWG wire isolated in free-space has a definite capacitance but it cannot be determined using the parallel plate formula given earlier. Using advanced methods we can actually calculate its value (which I won't get into). This is an important type of capacitance that affects the properties of radio antennae and is called the ISOTROPIC capacitance of the wire. (Isotropic meaning the capacitance is the same in all directions.)

To conclude, only examine Dollard's work as a "primer" on the physical relations. DO NOT take them to be "gospel," as they can't be used for normal things that you have on your desk, such as a toroidal coil or a vertical wire. The basic idea that something is proportional to some other stuff is what you need to focus on understanding, and then always remember that it's a "first principle" thing that must be modified for your application.

Try getting a book on trigonometry (McKeague 7th ed.) and after you've mastered the identities and functions, move on to calculus (Stewart early transcendentals 7th ed) and THEN go deeper into either physics or electrical engineering. You have to have a strong math back ground (that's beyond everyday algebra) to comprehend why there are many different formulas for calculating the same things. Without a solid foundation in advanced math you will only remain lost and confused.

@upgradd Thanks for your comment!

On (1): It is somewhat confusing all those greek letters, that is, in Steinmetz his writings. But I like how Eric uses Psi and Phi, and the formula he uses, it seems so much simpler than everything else I've seen. But then again, like you said, it doesn't tell the whole story. Could you tell me more about what this obstacle is you are talking about? I don't seem to quite understand it.

On (2): Thank you for all this information, I will try to keep this all in mind, it is most useful. I have just one question left. I'm reading Eric's and Steinmetz their work because it explains things more "clearly" then everything else I've seen and because they don't talk about electrons, charge and such. So my question is, are there any books/papers I could read that are somewhat in the same line that talk about more practical stuff?

[upgradd]

I take it by your grammar that English is not your primary language. In consideration of the apparent language barrier, I'm not terribly sure how to respond to your questions but here goes:

The "obstacle" was literally the issue of notation, nothing else was implied.

Don't be scared of "electrons," "charge," or any other quantity: they are just names used to describe certain phenomena. Know that Dollard uses these same quantities regardless of his dislike for their names or deeper properties proposed by physics.

To decide if something is false, you must first understand what it is, what is is supposed to do, and then devise an experiment to test whether it does or does not do what it should do. The beauty of physics, is that it is an experimental science, and you, as an individual, have the power to experimentally prove and disprove concepts by empirical and quantitative analysis. Know that Dollard has yet to provide either empirical or quantitative data to disprove current theory: he merely speaks his mind from a 19th century point of view. Know that multiple models of a phenomena can work, but ultimately you have to decide on using one or the other so as to be able to communicate with other people. Using Dollard's system will ostracize you from the mainstream, which isn't a good idea if you plan on higher education or getting a job in electrical engineering or physics.

As for your second question, all books and papers published on EE or physics from the 1940s onward will not use the Dollard/Steinmetz nomenclature or concepts. You will have to contend yourself to learning two ways of understanding the subject of physics. There is no easy way out. Don't be scared of learning a different model. Equally important, don't take any one model to be dogma or the "correct one." Case in point, chemistry is full of fake models that are known to be wrong, but they are extremely helpful, although limited, in explaining certain things. For example, Lewis structures and hybridized atomic orbitals are just plain wrong, but organic chemists love using them to explain bonding.

Loopholes, plot-holes and paradoxes exist within every theory (Dollard's is no exception to this), just be mindful of them and know that they only represent a "model" of the phenomena. It doesn't mean that's how nature works, just that this is one way to explain how it MIGHT work.

In conclusion, don't be afraid of mainstream science.

[Web000x]

I take it by your grammar that English is not your primary language. In consideration of the apparent language barrier, I'm not terribly sure how to respond to your questions but here goes:

The "obstacle" was literally the issue of notation, nothing else was implied.

Don't be scared of "electrons," "charge," or any other quantity: they are just names used to describe certain phenomena. Know that Dollard uses these same quantities regardless of his dislike for their names or deeper properties proposed by physics.

To decide if something is false, you must first understand what it is, what is is supposed to do, and then devise an experiment to test whether it does or does not do what it should do. The beauty of physics, is that it is an experimental science, and you, as an individual, have the power to experimentally prove and disprove concepts by empirical and quantitative analysis. Know that Dollard has yet to provide either empirical or quantitative data to disprove current theory: he merely speaks his mind from a 19th century point of view. Know that multiple models of a phenomena can work, but ultimately you have to decide on using one or the other so as to be able to communicate with other people. Using Dollard's system will ostracize you from the mainstream, which isn't a good idea if you plan on higher education or getting a job in electrical engineering or physics.

As for your second question, all books and papers published on EE or physics from the 1940s onward will not use the Dollard/Steinmetz nomenclature or concepts. You will have to contend yourself to learning two ways of understanding the subject of physics. There is no easy way out. Don't be scared of learning a different model. Equally important, don't take any one model to be dogma or the "correct one." Case in point, chemistry is full of fake models that are known to be wrong, but they are extremely helpful, although limited, in explaining certain things. For example, hybridized orbitals is just plain wrong, but organic chemists love using it to explain bonding.

Loopholes, plot-holes and paradoxes exist within every theory (Dollards is no exception to this), just be mindful of them and know that they only represent a "model" of the phenomena. It doesn't mean that's how nature works, just that this is one way to explain how it MIGHT work.

In conclusion, don't be afraid of mainstream science.

Anybody that has spent any significant time around Eric Dollard knows that he is something more than talk. I got to see him tune Mark McKay's Tesla Coils into a mode of excitation that left a few electrical engineers baffled including myself. There is more to this than your mainstream science. Maybe Eric uses 'obsolete' notation because it is closer to what Tesla was using?

Dave

[Gav]

Basically your confusion is about two things:

1) Specific notation:

For example, the Greek or Latin characters used to denote any one quantity, relation, or constant. This is a major obstacle for people who are new to the subject, which you appear to be. If you already know the physical relations and what the formulas are for, differences in notation don't really confuse you but they may certainly annoy you if they aren't your preferred choice. Dollard falls into this last part for almost everyone who reads his work: it's annoying to see obsolete notation.

2) The relationship of each equation:

Some of the equations you've posted are for demonstrating different aspects of the same thing. Such as how can you MEASURE an existing capacitance by using things you already have, such as a voltmeter, ammeter or coulomb meter (an electrometer comprises all of these). Or how can you CALCULATE the capacitance of a physical object by knowing the properties of the insulating materials and the area and dimensions of the conductors.

So putting it all together, don't get hung up on notation, it's entirely arbitrary as to what symbol you use for xyz quantity or constant. Just focus on understanding the physical relations which the author is trying to convey. For example, capacitance of any linear capacitor is proportional to the quotient of the charge stored divided by the potential difference between the plates (C = Q/V). OR capacitance of two flat parallel plates (neglecting fringing fields) is proportional to the area of one plate times the permittivity of the space between the plates and inversely proportional to the distance of separation (C = (e_r*A)/d).

Ultimately Dollard's formulas are impractical as they don't relate to specific geometries or physical conditions: he just gives you the basic physical model that can then, with advanced math (usually calculus), be used to derive a relation that will help you calculate your specific problem.

For example, a 10ft long 12AWG wire isolated in free-space has a definite capacitance but it cannot be determined using the parallel plate formula given earlier. Using advanced methods we can actually calculate its value (which I won't get into). This is an important type of capacitance that affects the properties of radio antennae and is called the ISOTROPIC capacitance of the wire. (Isotropic meaning the capacitance is the same in all directions.)

To conclude, only examine Dollard's work as a "primer" on the physical relations. DO NOT take them to be "gospel," as they can't be used for normal things that you have on your desk, such as a toroidal coil or a vertical wire. The basic idea that something is proportional to some other stuff is what you need to focus on understanding, and then always remember that it's a "first principle" thing that must be modified for your application.

Try getting a book on trigonometry (McKeague 7th ed.) and after you've mastered the identities and functions, move on to calculus (Stewart early transcendentals 7th ed) and THEN go deeper into either physics or electrical engineering. You have to have a strong math back ground (that's beyond everyday algebra) to comprehend why there are many different formulas for calculating the same things. Without a solid foundation in advanced math you will only remain lost and confused.

upgradd is exactly correct, myself, I think dollard is a distraction, he works with power and phone companys, but yet he is promoting FE? why would they hire him knowing that? I would follow the masters from the past before I followed dollard

[dR-Green]

The conspiracy theorists have entered the building, I see.

all books and papers published on EE or physics from the 1940s onward will not use the Dollard/Steinmetz nomenclature or concepts.

upgradd is exactly correct... I would follow the masters from the past before I followed dollard

Maybe Eric uses 'obsolete' notation because it is closer to what Tesla was using?

.

[upgradd]

The conspiracy theorists have entered the building, I see.

Care to elaborate, or are you acting out of discomfort when you hear people say things that might conflict with your own view of the world?

I have only stated what I believe to be common sense and helpful suggestion. If you feel I went beyond that--as you say into "conspiracy"--feel free to show how so. Otherwise you, yourself are the conspiracy theorist, by believing everyone else who disagrees with your worldview is wrong.

Furthermore, I never made any significant negative claims against Dollard, just pointed out simple facts: he has yet to rigorously prove any of his claims. And YES, he may well be very talented when tuning circuits, but that doesn't make his views correct. I could state dozens of highly intelligent people who's ideas are now considered as wrong (Darwin's agreement with the concept of gemmules or the caloric theory proposed by Lavoisier or the triple helix of DNA by Pauling etc.). So until OTHER people can independently verify his claims they remain just that: claims.

[dR-Green]

Care to elaborate, or are you acting out of discomfort when you hear people say things that might conflict with your own view of the world?

I wasn't talking about you or Dave. I was referring to the distraction and FE remark which is a good one seeing as Eric doesn't promote it and helps to actually get things built, and the irony of the statement to "follow the masters from the past before following Dollard", when he stands accused of using obsolete (old) terminology.