Flow of Electrons in a DC Circuit

[Ratch]

As others have pointed out, the idea of teaching - especially beginners - is to condense out only that information which is necessary to give a functional understanding and is according to their ability.  If the subject is physics, then by all means throw in quantum mechanics.  If the subject is mechanical engineering, then by all means include the chemistry of corrosion - but no matter what the discipline, you cannot succeed in teaching if you spend inordinate amounts of time labouring over points that are, in the big picture, comparatively insignificant.

Daddy, what is electricity?
Well, my dear, let me tell you about quantum entanglement 

Well, my dear, it is a form of energy.  Energy is the ability to do work.  Next question?

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[Ratch]

I don't see how water movement is easier than particle movement.  Why change the medium?

Ratch

Because I can safely pour water out of a bucket and a shared experience will tell us how it's going to work out.  The youngest child, having spilled their milk, knows exactly what is going to happen.

It's just a place to start.

Start what?  A lession in hydraulics?

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[Nerull]

Mr. Scram,

If I am asked to explain to a classroom of children or a random layman what electricity is and how it works, and I tell them what you just suggested, how many do you think have the faintest idea what I am talking about?

It would depend on their age, wouldn't it?  I would not attempt to teach something like that to children too young.  Most kids have experience with electrical appliances as well as a water faucet.

Teaching people effectively often consists of relating something new to something they already know. Very few concepts cannot be related to anything else, which are typically the subjects that people struggle with immensely. You do have to take care that the analogy is not extended to areas where it does not apply, but that should not be too much of an issue

I don't think it is needed in this case.

For reasons explained. If you sincerely do not see how it might be easier, I am not sure discussing this any further is useful. The horse has been led to water.

Easier and wrong.  You are right.  I am not convinced.

Ratch

I think it is very good that you are not a teacher.

Tell me, have you ever seen someone actually learn when you barge into a beginner thread, take it over with a silly semantic debate about technicalities irrelveant to the question asked, and drive the OP out of his own thread? I've seen it happen several times.

Every technical subject is taught using simplifications and then building on them. It's completely silly to do otherwise, and gets no where.

And yes, despite what you may wish to think about yourself, you're working with simplifications too. You are strutting around showing off the limits of your knowledge in order to pat yourself on the back, not to educate, but there are complexities you haven't learned yet either.

[Ratch]

Easier and wrong.  You are right.  I am not convinced.

Conventional current is wrong. Quantum mechanics and relativity will not play nice, which means our current models are wrong. Our understanding of the universe in incomplete and wrong. Effectively, we should stop teaching people about anything because everything is wrong.

We are feeble monkeys in a freighting universe. We cannot hope to be right, especially if we are not prepared to be wrong at first.

Conventional current is a mathematical definition.  It cannot possibly be wrong.  Haven't you read my previous explanation?  Why are QM and relativity involved in this discussion about current definition and direction?  What is wrong about our understanding of the universe?  How is everything wrong?  Please explain yourself.

Do you have a weak tail?  If not, how can you call youself or anyone else who does not possess such a appendage a feeble monkey?

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[TNorthover]

I am glad you agree that I am pedantic.  I cannot help it, so I give everyone warning with my tag line.

It's not pedantry unless you insist on string theory or some contender like LQG. What you're doing is picking an abstraction level at random and declaring it perfect.

[mtdoc]

The choice of medicine as a parallel was interesting - and entirely foolish, IMO.  Correct me if I'm wrong, but I am of the understanding that, as much as we have discovered about medicine, there is a great expanse of knowledge in this field that we do NOT know.

Absolutely correct. And it's a deficit that will not be corrected by a better understanding of the physics of cellular structure.

There's a reason that medicine is considered both Art and Science (not unlike some areas of electronics - a'la Jim Williams).  In fact a big reason I left my prior career in neuroscience was because I realized that no matter how much we understood the biophysics and physiology of neurons, we would never understand how the brain works without the ability to move away from reductionist modes of thinking. 

The reductionistic aspects of human physiology are fairly well understood (with some notable exceptions) but how the whole works together and how less understood factors contribute to health and healing is still an area where we know very little.

[Mr. Scram]

Well, my dear, it is a form of energy.  Energy is the ability to do work.  Next question?

So Timmy's dad has no energy? Does he need more electricity?

[Ratch]

mtdoc,

Yes, and teaching by at first simplifying and when necessary using analogies is a long proven method to teach complex material successfully.  That's what makes a truly great teacher: the ability to take a complex subject and simplify it in a way that allows a rank beginner to say "ah, now I get it!". Even if that simplification contains innaccuracies and ignores important caveats. There are plenty of college professors who aproach it the way you suggest and fail - most of them either don't care about teaching or have forgotten what it is like to have a "beginner's mind"

I agree with most of what you said above except the part about teaching inaccuracies to simplify things.  Unless the teacher makes clear to the student that the material is a simplification.

It should be both,otherwise it's being done wrong.

  I said it should be more satisfying that fun.  That implies both.

That's a very arrogant attitude to take in a forum that is made up of not only professional EE's but also hobbyists of all knowledge and skill levels who are interested in learning and enjoying their hobby regardless of their background or how much time they have available to devote to it. This is the beginner's section for christ's sake !!

I don't know what Christ has to do with this.  I addressed one post from a person on a particular topic.  I did not paint everyone with a broad brush.  You either agree or not, but it is wrong for you to impute that I insulted the whole forum.

Well, having been both a teacher of medical students and a medical student myself, I can say with absolute certainty that many subjects in pre-med and medical school are taught by beginning with over simplified and imperfect analogies and models. Many subjects never delve into underling first priniples and that is fine. Many imperfect, simplifed models of natural phenomenon prove perfectly adequate for practitioners in the real world - and that is true in many fields. Case in point: The example of using "conventional current flow" that arose from the OP of this thread.

And the point is?

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[Ratch]

Well, my dear, it is a form of energy.  Energy is the ability to do work.  Next question?

So Timmy's dad has no energy? Does he need more electricity?

If he is in the middle of a electrical blackout, yes.

Ratch

[Mr. Scram]

Conventional current is a mathematical definition.  It cannot possibly be wrong.  Haven't you read my previous explanation?  Why are QM and relativity involved in this discussion about current definition and direction?  What is wrong about our understanding of the universe?  How is everything wrong?  Please explain yourself.

An analogy is, by definition, non-identical. Therefore, it cannot possibly be wrong. Have you read my previous explanation? Why is the easier water anology wrong? Please explain yourself.

Do you have a weak tail?  If not, how can you call youself or anyone else who does not possess such a appendage a feeble monkey?

Instead of my tail, I used my nimble monkey fingers to press keys on a device with many buttons, which ultimately resulted in that message being transmitted. The message was encoded in the current flow by minute differences in electron pressure.

[rs20]

First of all, you and everyone else should not use the technical slang term "current flow".  Current already means charge flow, so that slang term really means "charge flow flow", which is redundant and ridiculous.  You should instead say current exists or current is present, and be syntactically correct. 

Oh God. So am I supposed to say that current "exists"  clockwise around a circuit? And given that a river is defined as a flow of water, speaking about the flow direction of a river must mean that I'm talking about the flow of a flow of water, which is redundant and ridiculous, right? I do hope you're hard at work furthering your pedantry whenever anyone stupidly says that the Thames river flows through London, that'd really make the world a clearer and better place.

[Ratch]

I am glad you agree that I am pedantic.  I cannot help it, so I give everyone warning with my tag line.

It's not pedantry unless you insist on string theory or some contender like LQG. What you're doing is picking an abstraction level at random and declaring it perfect.

Pedantry is not making something complicated or abstract.  It is a basically an obsession with correctness and perfection.  Next time consult a dictionary.

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[Ratch]

First of all, you and everyone else should not use the technical slang term "current flow".  Current already means charge flow, so that slang term really means "charge flow flow", which is redundant and ridiculous.  You should instead say current exists or current is present, and be syntactically correct. 

Oh God. So am I supposed to say that current "exists"  clockwise around a circuit? And given that a river is defined as a flow of water, speaking about the flow direction of a river must mean that I'm talking about the flow of a flow of water, which is redundant and ridiculous, right? I do hope you're hard at work furthering your pedantry whenever anyone stupidly says that the Thames river flows through London, that'd really make the world a clearer and better place.

What has God got to with it?  Depends on the circuit and the perspective.  Just a flow of water suffices.  The Thames does flow through London,right?

Ratch

[Mr. Scram]

Pedantry is not making something complicated or abstract.  It is a basically an obsession with correctness and perfection.  Next time consult a dictionary.

Thanks for that lession in verbal correctness and perfection.

Start what?  A lession in hydraulics?

[Ratch]

Mr. Scram,

An analogy is, by definition, non-identical. Therefore, it cannot possibly be wrong. Have you read my previous explanation? Why is the easier water anology wrong? Please explain yourself.

Fallacious reasoning.  Just because something is not identical does not mean it is correct.

Instead of my tail, I used my nimble monkey fingers to press keys on a device with many buttons, which ultimately resulted in that message being transmitted. The message was encoded in the current flow by minute differences in electron pressure

Why didn't you say so in the first place?

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[Ratch]

Nerull,

I think it is very good that you are not a teacher.

I do, too.  Low pay and little recognition.

Tell me, have you ever seen someone actually learn when you barge into a beginner thread, take it over with a silly semantic debate about technicalities irrelveant to the question asked, and drive the OP out of his own thread? I've seen it happen several times.

You got your facts all wrong.  I got a kudo from the OP.  Look at post #6.  It is you who is getting all bent out of shape for whatever reason over something you know nothing about.

Every technical subject is taught using simplifications and then building on them. It's completely silly to do otherwise, and gets no where.

And yes, despite what you may wish to think about yourself, you're working with simplifications too. You are strutting around showing off the limits of your knowledge in order to pat yourself on the back, not to educate, but there are complexities you haven't learned yet either.

I have never denied simplifications, especially when they are declared beforehand.  But, there is a difference between simplifications and false facts.

Ratch

[Ratch]

blueskull,

Ratch,

Did your teacher teaching science (other than math) in middle school or high school gave 100% accurate information? If not, did you fight him/her all the time?
Even in university, I'm talking about graduate level courses, we use a lot of simplifications. When getting into complicated things such as RF theories and control theories, many things don't even have a symbolic answer. We almost all the time have to simplify them to a 1/2 order system in order to solve them.
The fact is, if universally or practically almost universally the simplification gives almost exact result of its original solution, we don't even care about if it is actually true.
Modern electronics and computer and I believe many more industries are built upon reasonable educated estimations, some are not physically correct, but who cares if it works all the time?

I and the rest of the class asked for clarification all the time.  Sometimes the professor was correct and sometimes the class was.  I have no problems with simplifying things if it is made clear that simplifications were made and what the simplification were.

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[OpenCircuit]

It seems the answer is a bit more complex than I recall from Physics 101 20 years ago. I have no interest in arguing with anyone nor do I have the background to come here and argue. So please don't think I am taking a side or trying to take issue with you. I went to Law School and realized I don't want to spend my life in contention. The most I had as an undergrad was physics 101 for non-sci majors, so much of the discussion is simply beyond me, thus no response can be given. I remember discussing AC and DC in physics class, magnetics, basic waves theory but we never discussed which direction electrons actually “flow” or “float” or move-I see why now. Some of the back and forth amongst members is helpful but dopant atoms...what the hell are those? No wait don't answer that!   When talking over my head, I simply can't respond. I then simply wait and hope someone else comes along and responds while politely telling Albert “thank you.”

Here is where I am on the whole thing at this point:
If electrons are negatively charged I would think they would be attracted through the conductor/wire exciting anything in the “closed circuit.”  Here is wikipedia's answer: “Direct current (DC) is a flow of electrical charge carriers that always takes place in the same direction. The current need not always have the same magnitude, but if it is to be defined as dc, the direction of the charge carrier flow must never reverse.” (https://en.wikipedia.org/wiki/Direct_current) fair enough they just didn't say what direction, guess whichever of you guys wrote that would minding your Ps and Qs. I can't tell you if I am more confused now than when I was, can you tell me? This is how a pupil builds on what they have learned, by confirmation and feedback. Patience is the key to an effective teacher. Mtdoc seems to have some wise things to say regarding this post in the beginners section, if the goal is to teach someone. Why does anyone (whoever is reading this) come here and engage? What is the purposed of these forums? Speech 101, who is your audience?

Anyway, the purpose of my diagram was to elicit an answer that would permit me to conclude which way those damned electrons were actually flowing on my own after trying to learn on my own-answers are exactly as I had suspected in my original post. Here we are.... I figured if a diode does not allow electrons to flow or “float” through in a certain direction I can safely conclude the “current” is going the other way and then formulate an explanation. Why? To understand a segment of circuitry on an ATX switching power supply (see other threads). Why did the EE design the circuit this way? I bought three broken PSUs just so I could learn from them. If I could fix one-GREAT I have demonstrated an understanding. If not, an inexpensive lesson in “microelectronics.” I feel compelled to say, however that electricity is very dangerous and beginners would be well advised to understand the hazards of working on anything dealing with electricity. The AC wire is moving is "alternating." [insert emoji of smiley getting electrocuted here] I will wait until my third or fourth week to start on dopant atoms. Anyone help me fix this $15 oscilloscope DIY kit, so I can start that learning block?

These forums are a tremendous asset to the advancement of society. Where else can one go and talk to electricians, physicists, etc. and learn informally. It is really great and is why I say thanks to  nearly everyone who respond to my posts. I feel a bit annoying at times as I realize asking an EE PhD student how a diode works, and what that is and then what this is gets annoying after a while. I really like the idea of a beginners section. I am trying to put together models in my head....why a resistor on a diode- but not now. Being new and people being asses in their responses is worse than dopant atoms talk in this thread-not referring to anything in particular in this thread.

I have been trying to pay more particular attention to my terminology and am always trying to confirm the basic concepts I am working with in my head. Water flow works well for me which to get started.. That damn diode symbol seems to be a tricky question.

“Just follow the arrow” should work for now.

Thanks everyone for your responses. I hope I haven't crossed anyone in my responses as it seems like a nice community at first glance.

[Brumby]

“Just follow the arrow” should work for now.

That's all you'll need ... for quite a while.   

[Brumby]

For the record, there are two terms used when discussing this topic (as in your original question)

1. Conventional current
and
2. Electron flow

Conventional current is the one that is used - almost exclusively - in the field of electronics.  It comes from the arbitrary assignment of positive and negative when electricity was first being investigated and the logical allocation of current flowing from positive to negative.  Yes, they got it wrong, but the whole industry uses this convention.

Electron flow is exactly what it says - but you don't need to worry about this unless you are working at chip design level or with vacuum tubes.  Even then, the circuit diagrams will be drawn up using conventional current flow annotations.

By all means understand that Electron flow is technically correct - and then forget about it.

As you said:

“Just follow the arrow” should work for now.

[mtdoc]

   I did not paint everyone with a broad brush.

You left out your quote which I was responding to:

  A student must decide if he wants to have good knowledge of a subject or be a dilettante.

That's a pretty broad brush there- IOW "agree with my definition of "good knowledge" or you're a dilettante".

And the point is?

The point is that based on direct experience, I know that your statement - which I was responding to (and which you conveniently left out) - is false:

If medicine were taught without the full background, we would be graduating witch doctors

I'm guessing based your responses in this thread that you'll be happy to continue this ad nauseam.  I think it's more than pedantry.  Suffice to say myself and others here disagree with your ideas on pedagogy. Perhaps we can leave it at that and get back to the OP.

[mtdoc]

Thanks everyone for your responses. I hope I haven't crossed anyone in my responses as it seems like a nice community at first glance.

You've crossed no one - we've done it to ourselves.

It is a nice community here - just don't be too bothered by those of us who occasionally wander and enjoy a good off topic debate.

By all means understand that Electron flow is technically correct - and then forget about it.

Yep. Exactly. That's the ticket!

[Brumby]

Thanks everyone for your responses. I hope I haven't crossed anyone in my responses as it seems like a nice community at first glance.

You've crossed no one - we've done it to ourselves.

Indeed.

It is a nice community here - just don't be too bothered by those of us who occasionally wander and enjoy a good off topic debate.

Yeah ... that happens now and then.

[basinstreetdesign]

The most important things are that no one was hurt and no one was arrested!

[A Hellene]

Come on, guys!

Is it so difficult for any educated individual to understand the actual reason of the so-called CONVENTIONAL versus the ACTUAL electrical current polarity discrepancy?

It is not about 'mathematical modeling' because even during the time of the BJT invention, a few decades ago, scientists (both the real and the false ones [those who were dogmatically imposed to the Academia by the establishment]) were actually more than certain that electrical charges had positive polarity! And the myopic character of the Academia (that can NEVER be wrong, neither do they accept the natural possibility of one of their theories can ever fail*) is to be blamed for NOT correcting any of their previous wrong assumptions --especially after any possible proofs. This is why they 'teach' the younger ones by using a confusing 'baby-talk' which can be demystified ('explained properly') only for those who will insist of examining the subject matter in a more rational and documented way...

For anyone disagreeing, please read that fine thread, where the following excerpt is coming from::

[...]
So, by sending electrons in the emitter and pulling them out of the base, it creates an electron flow. This is the base-emitter current (in electron flow the emitter-base current, but as it was not known electrons were negative in the olden days we assumed current flows positive to negative...)
[...]

By the way, this very thread above has pieces of information that can be found to be very-very interesting and/or eye-opening, even to those who THINK they know what they are talking about...


-George



[ * ] I am talking about all those pseudo-scientific inventions of that infamous Cantorian gang (Georg Cantor, David Hilbert, Felix Klein, Ernst Mach, Albert Einstein, etc., with their miserably failed 'Set Theory' and the perennially failed 'Distorted Spacetime') that rewrote Physics by ruthlessly obliterating the (two-dimensional / flat space) Euclidean Geometry and whose unsubstantiated inventions are still being taught in a religious manner as the absolute truth... Not to mention that gang's mates, Heaviside (that non-Academic tool who detested potentials and stated that they 'should be murdered from the theory' and whom the Academia accepted as one of their own along with his distorted inventions), Gibbs and Hertz for reducing 12 of Maxwell's 20 equations with 20 variables each to four simple equations with just four variables, that we now swallow as 'the Maxwell's equations' even if they are not...

What about the very recent 'Horava Gravity' theory of the Berkeley Physicist Petr Horava (whom Wikipedia diminishly calls 'a theorist') who concluded that allowing the space and the time to change independently of each other gravity becomes susceptible to quantum theory suggestions? What about the 1986 Ernest W. Silvertooth experiment that radically disproved the staged Michelson-Morley conclusions and the Cantorian gang inventions (the so-called 'speed of light absolute limit' and all its dogmatic 'derivatives')?

Is not a marvel that dogma-state we are in, thinking we know everything there is to know about when, in reality, we are just using a fraction of the knowledge and everything outside our simplified view has to be moronic and worthless? Do never forget that, a zillion examples that support a theory can never prove it; yet, it only takes one single experiment to kill it...