Thermionic Conductivity Advantages ??? Little Help, Please ...

[Kevenergy]

I'm working on Electronics Experiments and Very Interested in Thermionic Emissions to Increase Voltage Conductivity Advantages. From what I've Learned so far, Thermionics Encourage Electron Flow with Heat, and are Replaced by Current filling their Void. Please Help and Advise, Any Help on the Subject is Much Appreciated, Thank You in Advance !!! -Kevin.

 

[cowboybob]

Welcome, Kevin!

This is a good place to start: https://en.wikipedia.org/wiki/Thermionic_emission

 

[kubeek]

Voltage conductivity makes no sense, as current is what is being conducted. Also, you need vacuum to see any thermionic effects.

 

[Kevenergy]

Welcome, Kevin!

This is a good place to start: https://en.wikipedia.org/wiki/Thermionic_emission

Thank You, Cowboybob ! Electricity can be a Very Perplexing and often not an Obvious Thing on the Intricate Details of it. I mean Electrons Flow in the Opposite Direction of Current ??? God REALLY Cursed Us with some of the Mysteries of Electronics ... !!! 0;O) Thank You again, and I hope to benefit from Your Wisdom more as I Learn. -Kevin.

 

[cowboybob]

You're welcome, Kevin.

Although I have been told many times that my "wisdom" is suspect....

Paul

 

[kubeek]

I mean Electrons Flow in the Opposite Direction of Current ?

First thing was the conventional current direction from + to -, that was before someone discovered that electrons are actually negatively charged, so then you have the electron current direction, where electrons flow from - to +.
So god nor mysteries have anything to do with this, only people who defined things back in 1800s are responsible.

 

[Kevenergy]

First thing was the conventional current direction from + to -, that was before someone discovered that electrons are actually negatively charged, so then you have the electron current direction, where electrons flow from - to +.
So god nor mysteries have anything to do with this, only people who defined things back in 1800s are responsible.

I Hear You, From When I was 10 Years Old On, I'd ask the local auto parts stores, "You mean the Positive Terminal of a Battery is actually Packed Full of Negative Electrons ???" NONE of them could answer that. Thank You for Your Response ! -Kevin.

 

[JimB]

Fifty or more years ago when I was just getting into this electronicy stuff, I too thought that electrons flowed from +ve to -ve. I had not worked out that conventional current and electron flow were not the same thing.

This made understanding valves (tubes in the USA) very difficult.
Once I had discovered the difference, things made a lot more sense.

Nowadays, when analysing a circuit, I only ever think of conventional current.

JimB

 

[cowboybob]

I suspect that the early electrical thinkers thought of energy (current) "flow" as mimicking heat, i.e., from a "+" temperature to a "-" temperature.

And I'm with JimB concerning the electron flow in tubes as from cathode (negaively charged) to plate (positively charged), which followed my understanding of carbon battery theory.

But, at least to date, I still refuse to follow the pack and think of current flow in solid state devices as from "+" to "-". For instance, I see current flow in an NPN transistor as from emitter to collector: a heretical position to the purists of the concept. And think about the terms emitter (puts out) and collector (gathers in)!

And while I think I understand the why of that convention ("hole theory" and all) I am, nonetheless, convinced the theory was postulated to account for the need to make the math of solid state physics work: it needed a negative multiplier for the math to give a positive, and therefore accurate, solution.

This was accomplished by introducing into said math the infamous " i ", or imaginary number (the square root of -1, for which, of course, there is no answer but if squared yields -1: the negative multiplier). I think that if you check, the i symbol is never alone in a formula but is always, eventually multiplied by another i to force a -1 result.

Not that what I think matters. Just that my circuits, for the most part, make sense to me and work...

 

[Kevenergy]

I too thought that electrons flowed from +ve to -ve. I had not worked out that conventional current and electron flow were not the same thing. Once I had discovered the difference, things made a lot more sense.

Nowadays, when analysing a circuit, I only ever think of conventional current.

JimB

Thank You Jim ! Would it be correct as an Analogy to Picture or Say that a Positive Terminal of a Battery has Fewer Electrons than Protons, or a Void/Lack of or Vacuum for Electrons, and The Ground / Negative Terminal has a Surplus of Electrons ??? I wish they would have just used the Terms Positron & Negatron to begin with ... !!! ;O) Thanks Again ! -Kevin.

 

[Kevenergy]

I still refuse to follow the pack and think of current flow in solid state devices as from "+" to "-". For instance, I see current flow in an NPN transistor as from emitter to collector: a heretical position to the purists of the concept. And think about the terms emitter (puts out) and collector (gathers in)!

And while I think I understand the why of that convention ("hole theory" and all) I am, nonetheless, convinced the theory was postulated to account for the need to make the math of solid state physics work: it needed a negative multiplier for the math to give a positive, and therefore accurate, solution.

This was accomplished by introducing into said math the infamous " i ", or imaginary number (the square root of -1, for which, of course, there is no answer but if squared yields -1: the negative multiplier). I think that if you check, the i symbol is never alone in a formula but is always, eventually multiplied by another i to force a -1 result.

Not that what I think matters. Just that my circuits, for the most part, make sense to me and work...

Thank You Paul !!! I've heard the Analogy that Current doesn't Flow down the River, Water Flows down the River, Yet that doesn't allow for Current going in the Opposite Direction. I wish they would have used the Terms Positron and Negatron to begin with ... ;O) Regarding Transistors, I originally assumed Emitter (Puts Out) to the Load Side, and Collector (Gathers In) from the Supply Side i.e. Brought in to Collector and Passed on and Out through and From the Emitter to the Load. Other than That, It's just as Clear as the Nose on My Foot ... LOL ! Thank You Again ! -Kevin.

 

[Ratchit]

To the Ineffable All,

Every so often I have to remind everyone that current is charge flow. So when you say "current flow", you are really saying "charge flow flow", which is redundant and ridiculous. You should just say "charge flow" instead.

So many folks get wrapped around the axle by worrying about the polarity of the charge carriers when they make current calculations. Who cares? For current calculations, always assume that the charge carriers are positive, and that they travel from the positive terminal of a voltage source to the negative terminal. You are going to be right 50% of the time anyway, because there are as many positive charge carriers such as semiconductor holes as there are negative carriers in the universe. Conventional current should really be called "mathematical convention current". If and when you have to get down to the physics of the circuit, and need to know the actual direction of the current, just leave the direction as calculated for positive charge carriers, and reverse the direction for negative charge carriers like electrons. The forerunner scientists of old would have been just as "wrong" back then if they designated the electron as positive, because then all that we now call positive would be negative and vice versa. To summarize, use the mathematical current convention for calculations, and worry about the current direction after the calculations, and only if you need to do so.

There is a lot of confusion and bemusement about what "i" or "j" is. A lot of blather intimates that it represents numbers that are ethereal, imaginary, incomprehensible, not in this continuum, etc. Some folks think that sqrt(-1) doesn't exist. Well, it does exist, as much as any positive real number does. You see, "i" is a mathematical operator. i5 does not mean i + i + i + i + i . It means instead, rotate the number 5 90° counterclockwise (CCW). "i" is a mathematical rotational operator, not an arithmetic constant. True, you get correct answers by treating it as an arithmetic constant, but that is because it has "conformal similarity" to the orthogonal direction. Conceptionally, "i" should be thought of as a mathematical operator. So what is sqrt(-1)? Take -1 in polar form as 1/_180°. Then sqrt(1/_180°) is 1/_90° . This value is just as "real" as 1 is. It has magnitide and a relative direction, so it should not be called imaginary. Sometimes "i" by itself is used to represent the constant 1/_90°. In that context it is a constant, not an operator.

Ratch

 

[KeepItSimpleStupid]

I mean Electrons Flow in the Opposite Direction of Current ??? God REALLY Cursed Us with some of the Mysteries of Electronics ... !!! 0;O)

Ben Franklin made the mistake. So, far it matters somewhat when studying tubes, electron microscopes, solid state physics and chemistry.

The flow water flow model breaks down sometimes. Another way to look at "electron flow" is the continuous bumping car approach. The cars at the amusement ride. One car/electron hits another etc.

 

[cowboybob]

Thank You Jim ! Would it be correct as an Analogy to Picture or Say that a Positive Terminal of a Battery has Fewer Electrons than Protons, or a Void/Lack of or Vacuum for Electrons, and The Ground / Negative Terminal has a Surplus of Electrons ??? I wish they would have just used the Terms Positron & Negatron to begin with ... !!! ;O) Thanks Again ! -Kevin.

Yes. At least in my book of all knowledge...

 

[Ratchit]

KISS,

"Ben Franklin made the mistake. So, far it matters somewhat when studying tubes, electron microscopes, solid state physics and chemistry."

What mistake did BF make? Did you read my last post?

"The flow water flow model breaks down sometimes. Another way to look at "electron flow" is the continuous bumping car approach. The cars at the amusement ride. One car/electron hits another etc."

And what about when electrons move in a vacuum, as when they eject from an electron gun and strike the phosphor of the CRT screen? There are a lot of ways for charge carriers to flow.

Ratch

 

[KeepItSimpleStupid]

Yea, I know, the bumping car approach breaks down too. I never said it was completely accurate.

A discussion on conventional current flow: https://physics.stackexchange.com/questions/17109/why-is-the-charge-naming-convention-wrong

 

[Ratchit]

Kevenergy,

"Yet that doesn't allow for Current going in the Opposite Direction."

What is the problem of current existing in the opposite direction of its mathematical calculation?

"I wish they would have used the Terms Positron and Negatron to begin with ... ;O)"

It would not make any difference. There are two types of charge carriers (positive and negative). If you assume a direction for one type, it will be wrong for the opposite type. It is best to stick to a standard (mathematical convention) and determine the direction lastly if needed.

"Regarding Transistors, I originally assumed Emitter (Puts Out) to the Load Side, and Collector (Gathers In) from the Supply Side i.e. Brought in to Collector and Passed on and Out through and From the Emitter to the Load."

The emitter supplies charge on the source side and the collector gathers charge on the load side. The difference in NPN and PNP is the polarity of the charge carriers. If it is not clear , then you should ask about it.

Ratch

 

[Kevenergy]

I'm inclined to try to stay toward the Straight Plasma Arc Super Heating and Ionizing the Air Conducting across the Potential Barrier. Please let me know Your Thoughts. This sounds too inefficient:
From a physical electronic viewpoint, thermionic energy conversion is the direct production of electric power from heat by thermionic electron emission. From athermodynamic viewpoint,[1] it is the use of electron vapor as the working fluid in a power-producing cycle. A thermionic converter consists of a hot emitter electrode from which electrons are vaporized by thermionic emission and a colder collector electrode into which they are condensed after conduction through the interelectrode plasma. The resulting current, typically several amperes per square centimetre of emitter surface, delivers electrical power to a load at a typical potential difference of 0.5–1 volt and thermal efficiency of 5–20%, depending on the emitter temperature (1500–2000 K) and mode of operation. Details of the history, science and technology of thermionic energy conversion can be found in books on the subject.[2][3]

Thank You Very Much !!! -Kevin.

 

[cowboybob]

...There is a lot of confusion and bemusement about what "i" or "j" is. A lot of blather intimates that it represents numbers that are ... imaginary ...

My emphasis.

Ratch, old buddy,

"i", or actually "j", as it's used in electrical engineering, is most assuredly considered an imaginary number. Note:

https://en.wikipedia.org/wiki/Imaginary_unit

And, as a second source, Diefenderfer's "Principles of Electronic Instrumentation" (1979), in the appendix, page 438.

Both emphasize that j is, indeed, imaginary in that no such number exists.

That's not to say that in electronics (and elsewhere as well) it is not useful and necessary (if manipulated correctly) to describe, for instance, phase alteration caused by certain components.

I just took exception to the emphasized portion of the statement above.

And my apologies to the OP (and the Forum) for even bringing it up...

And, Kevenergy, should fusion energy production ever actually get past breakeven, let's hope thermionic conversation is by then a robust reality and the answer to electrical power production. Creating steam and using it to mechanically produce electricity would simply appear utterly inefficient and so "yesterday"...

(Edits are for spelling...)

 

[DerStrom8]

"i", or actually "j", as it's used in electrical engineering, is most assuredly considered a imaginary number.

In my experience, "i" is generally used in mathematics and "j" is used in electronics (mainly for complex impedance, reactive power, etc).