You don't need to understand the nature of charge carriers to build a circuit, have a lifetime hobby in electronics - or even for a career in EE.
Very often we have people who have no idea on what is going on - and the conventional phrases are useful in building a functionally useful understanding. Yes, they may be absolutely horrendous in regards to complete accuracy, but they are common terms that are frequently used, because the key concept is being communicated. This is how I got the feel of how things worked and I was able to create success on the circuit in front of me. Proper understanding followed later
Once they are comfortable with the basics and they are seeking to expand their understanding, then take things up a level - but at the moment, it is likely to confuse the hell out of a beginner, when it just is not necessary.
I have heard that argument before. I believe that learning the correct terminology, definitions, and the correct way things work at the beginning helps eliminate the need to "relearn" the correct knowledge later. Observe the multitude of folks who say and think that current flows. Furthermore, learning the correct things at the beginning is not that much harder.
I observed that most problems occur because the student does not have a good background of physics. As you undoubtedly know, physics and math are the foundation sciences of electrical knowledge.
BUT - if you take an electronics beginner without that background and throw it at them from the outset you will only confuse them and perhaps drive them away.
The alternative is tell them "go take a college freshman level physics course and math through calculus then come back.." Completely unnecessary and counterproductive IMO.
I use basic algebra quite a lot, but it's rare that I have to apply anything more advanced. Calculus comes in handy a little now and then but it's pretty rare that I have to actually solve any of that by hand.
Having spent 7 years of my life teaching introductory and more advance college courses (biology, physiology, neuroscience) I can tell you from first hand experience that no matter what field, any complex material must first be approached using imperfect analogies and carefully avoiding confusing students with caveats and divergence into first principles. If you do they will absolutely "lose sight of the forest for the trees" and for many that will drive them away. For others their initial advancement will be stunted and incomplete because of the diversion.
I am (and have been for a few years now) a student of electronics, taking online courses, reading, playing with circuits, building and repairing. Because I have a technical background, and spent years using test equipment in an electrophysiology setting, I've been guilty myself of getting lost in the trees because I already knew enough about the underlying physics, etc to start following that path.
Complex subjects need to be broken down and oversimplified to begin then as understanding advances, caveats and more precise models introduced. It's incorrect to say that the time tested methods of teaching complex subjects involve teaching "incorrect terminology" or "incorrect knowledge".
Yes, of course it helps if you already have had the foundational physics and math but it's been proven over decades that people without that - hobbyiests, hams, etc without a strong basic science foundation, can learn basic electronics, build functional circuits, have fun without that. If they have a curious mind they will pick up the basics of these subjects along the way. They may eventually even delve into them in depth.
BUT - if you take an electronics beginner without that background and throw it at them from the outset you will only confuse them and perhaps drive them away.
The alternative is tell them "go take a college freshman level physics course and math through calculus then come back.." Completely unnecessary and counterproductive IMO.
It is not complex material that impedes students, it is the way it is taught. Things like vague definitions (voltage is an "electric force") and using analogies as models ("think of electricity as a pipe full of water") are not too helpful. Analogies should be used to make a point, not as a model for an alternative way things work.
It is not complex material that impedes students, it is the way it is taught. Things like vague definitions (voltage is an "electric force") and using analogies as models ("think of electricity as a pipe full of water") are not too helpful. Analogies should be used to make a point, not as a model for an alternative way things work.
Analogies like that are helpful to me in grasping basic concepts, and I know I'm not the only one. You can't see electricity, and for someone who is not particularly technical the water analogy works reasonably well. I'm a very visual thinker and never gathered much from theory and mathematical study and I struggled with a lot of math until I was able to visualize it in a practical sense and then it made sense.
This may not be helpful to you, but that doesn't mean it is not helpful to others.
I hope no one gets wet using hydraulics as a teaching aid. Do hydraulic engineers use electrical circuits to learn their craft?
I hope no one gets wet using hydraulics as a teaching aid. Do hydraulic engineers use electrical circuits to learn their craft?
You are missing the point.
There is a reason the "water analogy" gets used in certain situations. It is because the particular elements of whatever water construct used are visually obvious. So obvious, in fact, that they can be more than adequately understood with a line drawing - and often, by just using one's imagination. Your effort at a contra argument completely fails on this point alone.
I hope no one gets wet using hydraulics as a teaching aid. Do hydraulic engineers use electrical circuits to learn their craft?
Simple electrical circuits can be easily imagined using Kirchoff's two laws. No other analogies needed. Hydraulics do not have fields, reactance, or binary flow (like holes and electrons) occurring at the same time.
People have no intuitive notion of electricity and associated forces. People generally have a very intuitive notion of water, pressure and flow. Comparing what is completely abstract with something you deal with every day helps understanding things quicker. Even things like current are shared between the analogy and the real thing.
KCL can be more easily understood thinking of current as water flowing into and out of pipes. What's your point?
If the teacher first explains that circuit current is charge particle movement along a conductor, he has everything he needs to build from there without referencing hydraulics.
I don't see how water movement is easier than particle movement. Why change the medium?
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?
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
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.
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.
I don't see how water movement is easier than particle movement. Why change the medium?
Ratch
Easier and wrong. You are right. I am not convinced.
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.
It is not complex material that impedes students, it is the way it is taught.
Learning a subject if more satisfying than fun.
A student must decide if he wants to have good knowledge of a subject or be a dilettante.
If medicine were taught without the full background, we would be graduating witch doctors.
I imagine Ratch's response might be along the lines of - let's be right when we can.
A student must decide if he wants to have good knowledge of a subject or be a dilettante.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 !!
QuoteIf medicine were taught without the full background, we would be graduating witch doctors.
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.
Now that we have a definition, let's use it....
We now look at electrical circuits and see charge moving around in mathematically describable ways. So we can talk about the current in each part of that circuit. But what happens when the mathematics say that there is no flow of charge in a particular section?
Conventionally, we say that the current is zero - but since your definition of current is immutably bound to the concept of "flow" being a real verb with all the powers of a verb on its own, the definition falls down. The term "current" has no meaning. We are simply looking at "charge". Try floating that into a beginners understanding and see them howl in anguish - or run for the hills.
You might object to the term "current flows", but I expect you would be OK with "current exists" yet, when it comes down to the key issue of communication, the basic concept is identical. The use of the term "current flows" is descriptive - it follows the fundamental concept of electrons moving along, usually in a confined corridor, just like water down a stream. The term "current exists" is far less descriptive and depends on a clear understanding of the definition of "current" before you can appreciate what is meant and only then can you look at applying it to the circuit.