Conventional vs. Electron Flow Electronic Usage

Factual Questions
1

Hi y’all,

I’ve been meaning to get around to teaching myself basic electronics with the view of doing some Arduino stuff and simple robotics. I Googled around and found a neat course here and thought the subjects covered were just right. It’s well written and goes from DC and AC through semiconductors and digital with questions and is pretty comprehensive. The problem is somewhere around the sixth or seventh section he points out that the course will be using the Electron Flow Convention. His reason is essentially that the book was written to be consistent with some other courses where it was originally introduced. He concedes that most of his training was done with Conventional Flow.

My question (and problem) is how much of training and courses are done with Electron Flow vs. Conventional? I know some DC electronics and a little IC stuff but everything was always Conventional. I’m not really in the mood to start thinking of diode symbols as being “shower-heads:)”. So the GQ is what percentage of electronics (both courses and real-world work) is done in each of the respective conventions?

Rather than start an IMHO thread: As an aside, does anyone know of any good online (or paper, even) courses?

2

This probably isn’t going to be helpful to you.

For most practical applications, it doesn’t really matter. Circuit diagrams and schematics don’t generally come in different “flavors,” with some using conventional current and others using actual electron flow.

However, there actually are real world situations where electron flow makes a huge difference. For example, conventional telephone circuits (tip and ring) are basically positive ground circuits. If they were not, buried copper conductors would be gradually eroded when the insulation breaks down.

The main reason I looked at this thread is that I had a student in one of my classes who absolutely insisted that conventional current flow was the ONLY “proper way” to visualize circuits. He actually went to the library at our state technical college and photocopied material out of several textbooks to prove this to me at the next class session. My response was, “Whatever makes you happy…”

3

> For most practical applications, it doesn’t really matter

For most technician-level issues, it doesn’t really matter. But in science, and a bit less so in engineering, it matters quire a bit.

All of science and engineering use Conventional Current.

Why?

Because “electron current” is wrong. It only applies to solid metals. Also, teaching with “electron current” is promoting some fundamental physics misconceptions which can mess up any students going into science, or into the higher level tech careers.

Main misconception: electric current is electron flow. Nope, wrong.

Another big one: protons cannot flow. Wrong, protons flow during electric currents in acid (batteries,) human bodies, oceans, the ground (damp dirt.) Any students religiously believing “protons cannot flow” are going to have big trouble with such things as biology, brains-neurons, biochem, and will never have much clue about how batteries work. None of these topics are based on metals and their electron flows, yet all require at least a simple understanding of electricity. “Electricity is electrons” derails this by hiding the ion-flows and proton-flows from the students, while installing a fairly rigid belief that such things don’t even exist. And, the main cause of this misconception is the false belief in “electron currents” versus conventional current.

Why use conventional current? Mainly it’s to simplify an extremely complex world. For example, in any copper conductor we have pairs of charges: the protons locked into the metal grid, and the mobile electrons. Electric currents in copper are not “electron flow,” instead they are a relative motion between the copper’s positive and negative charges. If we move the wire backwards at just the right speed, then the electrons in the wires stop moving, and the entire current is actually a proton flow.

But but …electron current is supposedly “more real,” or “facing reality.”

It’s not though. It’s dishonest, since actually facing reality would lead us right into studying the proton flows inside battery electrolyte and human nerves. (Copper wires aren’t the only type of conductor!) And, when a person gets electrocuted, no electrons flow through their body at all. (The currents are protons or +H ions, -OH ions, +Na ions, -Cl ions. And they flow past each other in opposite directions.) See, it’s complicated.

It’s so complicated that today we have a standardized method of concealing all the extra unwanted information. We don’t care about the various ions flowing in salt water and human tissue. We don’t care about the moving protons in metal wires which are physically moving. In a diode, or transistor, or fluorescent lamp, we want to pretend that the discharge is a single type of current, even though it’s not. So, we simplify: we assume that all these charges are just a single type. We pretend that any backwards-moving charges are actually moving forwards, so their current adds together with any forward-moving charges.

The method is called “Conventional Current,” where the flowing protons and ions and electrons are all assumed to have a single charge. To simplify our view of circuitry, no we don’t declare the charge polarity to be negative and flowing backwards! That’s needlessly complicated. Instead, it’s positive and flowing forwards.

“Electron flow” is an alternate method of simplification. (No, it isn’t more accurate than Conventional Current, in fact it’s less.)

Exactly where did this “electron flow” teaching method come from? World War II! It was created during WWII for teaching electronics repair to draftees who had little education (and might even have no schooling at all.) The electronics at the time was vacuum tubes and metal wires. The educators decided to settle on “electron flow” and hide the positives because it lets them quickly and simply explain how radio circuits and vacuum tubes work …while at the same time converting batteries into a complete mystery. But WWII repair techs won’t be going out for PhDs in the future, and certainly don’t need to know the innards of batteries, but very much need to know the innards of radio tubes, radar CRTs, etc. Do they end up with a set of misconceptions which might derail an engineering career, or prevent them from going into biochem or physics? Too bad, we have Nazis to defeat!

4

I think all of this is a false dichotomy.

In a copper wire, electrons flow. In that context, current is a current of electrons. They move from negative to positive. Ben Franklin, bless his heart, was exactly wrong, and now we know better.

In a battery, protons move, too. Right. You might notice that a battery is not exactly a copper wire, much like a synapse is not exactly a dielectric between two metal plates in a capacitor. Different scenarios require different explanations, and I don’t think it would overload anyone to teach them how to alter their mental model in different contexts, as long as the fundamental rules remain constant.

Maybe I’m too much of a physicist and not enough of an engineer. :wink:

5

Electrical engineers, technicians, hobbyists, pretty much anyone who works with electrical stuff all use conventional current flow. You’re just going to end up confusing yourself if you try to switch between the two. The physics guys are typically the only ones that use electron current flow. If you are going into physics, you want to learn it the electron way. If you are doing anything practical with electronics, you want to learn conventional current flow.

When I was in college (back in the stone age) my EE courses all used conventional current flow and my physics classes all used electron current flow. It was a royal pain in the backside.

ETA: I haven’t looked at any online courses, but if you really want to learn electronics, “The Art of Electronics” by Horowitz and Hill is by far the best book you can ever buy. It’s a bit pricey, but worth it (IMHO). Might be a bit advanced for someone who just wants to do arduino stuff though.

6

wbeaty nailed it.

I used to have an electronics circuits book published in the 1960s that used electron current flow in all the diagrams and formulas. Since I was taught to analyze circuits using conventional current flow, I found the book unreadable. I threw it in the garbage. :stuck_out_tongue:

7

I’ve never seen “the direction of current” in physics used to mean anything other than “the direction that positive charges would have to flow in order to produce that current”. In almost all cases, the direction of motion of the charge carriers makes no difference. In the few cases where it does make a difference (like the Hall effect, or a cathode ray tube), it’s just referred to as “the direction of motion of the charge carriers”.

So in other words, even if you’re going into physics, you should still use conventional current, because that’s the convention, and doing otherwise will only confuse you for no good reason.

8

You are going to have an interesting time explaining collector and emitter in both PNP and NPN transistors otherwise.

(The only reason that there are no negative anode thermionic tubes/valves is not that electrons won’t flow that way, but rather that the charge carriers needed are a trifle messy to generate. The same also accounts for the asymmetry between physically realised PNP and NPN devices.)

9

Regarding Physics:

One of the most basic facts learned in E&M is the Right Hand Rule. That uses conventional current. If it used electron current, it’d be the Left Hand Rule.

So a whole lot of E&M is oriented about conventional current.

I grew up and learned Electronics when there was still some vacuum tube stuff. While those are electrons flowing past the grid, we didn’t really care in analyzing and building stuff. It was the characteristics of the tube that mattered. How those characteristics got there weren’t our problem.

(Another place where it’s important to realize that it’s electrons moving around are in things that involve discharging a current into something: e.g., ionizers, those spiky lightning discharge devices, etc. But you don’t have a standard current flow and you’re getting into the realm of static electricity.)

Technically, you could call electrons “doughnuts” and teach a course in Doughnutics around the flow of doughnuts, but that’s just stupid. Conventions help people to communicate.*

*Insert Feynman story about his weird Math notations.

10

Bolding mine. This, as a trained electrician who was taught that current flows from positive to negative, made me crazy. I had an exhausting conversation with a prof that just served to further confuse me.

11

Hey! Big thanks all around.

I agree with Crafter_Man that wbeaty hits the nail on the head. The core of the OP question was who uses which convention and what’s the distribution of usage like. I know some basic DC electronics and had never seen anything using the electron flow convention. I know that they’re essentially equivalent as others have pointed out but using one convention alone has benefits. It’s funny that wbeaty should mention the source of the electron flow convention being the Armed Forces. The ebook’s author’s experience stems from learning and teaching in the Navy and an early concern with vacuum tubes. The only vacuum tubes in my life are attached to my shop vac .

Thanks so much** engineer_comp_guy** for mentioning Horowitz. I saw the text touted on AvE’s YouTube channel and liked what he had to say about it. (AvE is an engineer who goofs around in his home shop but knows a great deal with lots of field experience and a sense of humor.) I’ll get the book because I like knowing things in some depth besides the short terms goals mentioned.

ftg mentions the left-hand rule. I think when the ebook from the OP mentioned a left-hand rule is when I came to post this thread here. Having a left-hand rule and a right-hand rule is nutso. It’s like saying, “Half of the time we’ll be using reverse alphabetical-order mnemonics.”

I’ll probably plug along a little more with the course originally mentioned and see if the directional current arrows fade from view as it progresses. I do like the guy’s writing style and diagrams so it’s worth an small extra look.

Thanks again…

12

I recall being told in Chemistry class in high school that the convention for our class was that the current in a voltaic cell flowed in the direction that the electrons moved, since chemistry is basically all about electrons. We were also told that if we were to take physics, they used the opposite convention, saying that current flowed in the direction of positive charge movement. Which is exactly what we did learn in physics. So I’m very confused by people who claim that physics people use the convention that the current flows in the direction of the electrons. Maybe it’s just something of a generational shift, which would be explainable if WW2 training was part of the issue.

As a side note, one of the reasons why saying the current flows in the direction of electron movement is that the drift velocity of electrons is extremely tiny compared to the flow of current. Current can flow basically at the speed of light, while the drift velocity of the electrons is generally less than a millimeter per second from what I can find off-hand. On the other hand, an electron’s total velocity is usually somewhere in the magnitude of a kilometer per second. Most of its movement is effectively random with very very little bias in the direction it is moving due to the current. But there’s enough of them and enough of a bias so that the bias propagates and continues the current flowing.

13

As a handy example to extrapolate from, if you’ve got two feet of copper wire hooked up to a 1.5 volt cell, the drift velocity comes out to just about exactly a centimeter per second.

14

  1. So in you could point to that loop, if it could be moved around a racetrack at that speed, and say “electrons are stop time?” (Relatively speaking–and would SR have anything interesting to demonstrate about that?)

  2. Wasn’t/isn’t there a history to why the hell did they call the anode an anode instead of a cathode, because teaching electricity fundamentals starts off backwards?

15

When Michael Faraday was researching electrical stuff, he described current as going from “east” to “west” (rather confusingly to someone who has studied electricity using modern terms). Faraday consulted William Whewell, who suggested using the Greek words ἄνοδος (anodos), meaning ascent, and κάθοδος (kathodos), meaning descent, with the idea that ascent and descent described east and west with the movement of the sun. That led to the modern use of “anode” and “cathode”.

16

Thanks.

Ignorance fought, and food for semantic games: the most common word for immigration to Israel is “aliyah”–you might hear in English someone say “he made aliya”–which is from the Hebrew for “ascent.”

17

In a semiconductor, holes move too.

The OP’s question has an easier question. The unit amps is +ve when the electrons flow opposite. If you have some other unit of current flow, it may be electrons per second or Coulombs per second or something, well that would be opposite or ambiguous.

18

This begs a question, or is the question begged thereby answered: the physical locale of his experiments and the orientation of his apparatus.

My righthand rule runs so: I’m hitchicking in California and faint, my supine form headfirst to Mexico, my outstretched right hand replaced by a magnetic field oriented traveling palm- to-fingertip, the current travels west to east.

What might have been…

19

One supects Faraday chose east and west as the obvious pairing with using north and south for the magnetic directions.

20

Other alternatives to the right-hand rule