What is the Electron flow that we call it is a school work or a new newbie, you just have to know it, but probably you never use it again in the future, because the conventional flow is the common sense and using it everywhere.

 

And of course, this was all Ben Franklin's fault, when he defined current flow as being the flow of material in an electroplating solution as being the flow of material...which we NOW know to be ions. Ions flow the opposite direction of electrons (if indeed they can flow). Well, we can forgive old Ben for not knowing too much about electrons.

Yes, we simply honor his achievements (a remarkable new theory of electricity) by continuing with this idea that appeals to those that like water analogies (water from high pressure to low).

 

In MOST cases, as long as you're consistent, the direction of current flow isn't too critical, since the calculations for total charge movement all work out the same.

However, in something like a vacuum tube (or certain plasmas), the electrons are indeed actually flowing, and we need to associate that flow with MASS to do the right physics. In this case we really do need to know what's actually flowing.

 

Yes, we simply honor his achievements (a remarkable new theory of electricity) by continuing with this idea that appeals to those that like water analogies (water from high pressure to low).

Actually water flow analogies work just fine! I use them all the time to demonstrate Kirchhoff's Current Law.

 

(water from high pressure to low).

Maybe we all have bipolar.

 

if you cut a wire, which end do the electrons flow out of? electricity isnt like water in a hose or pipes. the direction of flow is just a learning helper. it helps us learn how electron flow (silly term, look up "drunkards walk" ) behaves in circuits.

 

You've got tickets on yourself Mike.

It is rather confusing since my teacher told me that current flows from positive to negative, and current is (n) quantity of electrons. However electrons travel from negative to positive. I don't ponder on theory such as this anymore and just accept it for as 'whatever' and concentrate on the kinetic side of things.

Current is the flow of charge. A current of one ampere at a point means that charge is flowing past that point (or, more precisely, through some defined area) at a rate of one coulomb per second in the direction defined as the reference for that current (i.e., the direction the arrow is pointing). If the current is composed of positive charge carriers, such as positively charged ions, then the physical charge carriers flow in the same direction as the charge. If the current is composed of negative charge carriers, such as electrons, then the physical charge carriers flow in the opposite direction. Now, if you want to define the reference direction for that current to be in the same direction as the physical charge carriers that's fine. Do so. But if the charge carriers are electrons then you have a (-1 C) flowing in that direction each second so you have a current of -1A. This is where the electron current people are almost always inconsistent. They want to say that the current in the direction of the electrons is 1A (or, more generally, a positive value) but they don't want to change a bunch of the equations they use and so they end up having to adjust their results here and there to reflect this by imposing a magical mystery minus sign from time to time.

 

Classic! Attached a file to the question.

I see the following defined currents in the diagram: Ia, Ib, Ie, If

These all appear to be defined such that positive current is current leaving the positive terminal of the respective supply, consistent with the flow of charge (i.e., conventional current).

The two unlabeled currents, #62 and #74, appear to be ion streams and I'm guessing (not sure that I understand the process completely) that they are positive ions flowing in the direction of the arrows. Note that they are not labeled as currents.

 

And of course, this was all Ben Franklin's fault, when he defined current flow as being the flow of material in an electroplating solution as being the flow of material...which we NOW know to be ions. Ions flow the opposite direction of electrons (if indeed they can flow). Well, we can forgive old Ben for not knowing too much about electrons.

It's not that Ben got it wrong (and I note that you are saying that it is his 'fault' as opposed to him getting it 'wrong'). His choice was completely valid and the system that developed around it is completely self-consistent and it works just fine for both positive charge carriers and negative charge carriers. Had he chosen the other way, then what we call the positive terminal of a voltage supply would now be the negative terminal and all of the voltages we talk about would be opposite in sign and everything would still be completely self-consistent and would still work just fine for both positive charge carriers and negative charge carriers. The choice was arbitrary, what is important is that the system be self-consistent. This is where the "electron flow" crowd always goes off the rails, they want to pretend that electrons are positive when it comes to describing currents but still use voltage definitions that are only consistent with them being negative.

 

In MOST cases, as long as you're consistent, the direction of current flow isn't too critical, since the calculations for total charge movement all work out the same.

However, in something like a vacuum tube (or certain plasmas), the electrons are indeed actually flowing, and we need to associate that flow with MASS to do the right physics. In this case we really do need to know what's actually flowing.

But that is independent of how you define charge flow.

For instance, if you know that the current is 100 A from left to right (meaning that 100 C of charge is flowing from left to right each second), then to find the mass flow from left to right all you have to do is convert the charge current to mass current by using the charge/mass ratio of the charge carrier.

\(
\text{I_{mass} \; = \; I_{charge} \frac{M_{carrier}}{Q{carrier}}}
\)

Notice how this equation doesn't care what the charge carrier is or how much charge each carrier carries. It works equally well for charge carries that are electrons, positrons, singly-ionized atoms, or multiply-ionized molecules.

For this example it would be

\(
\text{I_{mass} \; = \; 100\,A \( \frac{9.11 \times 10^{-31}\,kg}{-1.602 \times 10^{-19}\,C} \)} \; = \; -0.567 \frac{\mu g}{s}
\)

Thus we have negative mass flowing from left to right which means we have positive mass flowing from right to left.

 

Yes, we simply honor his achievements (a remarkable new theory of electricity) by continuing with this idea that appeals to those that like water analogies (water from high pressure to low).

Whether the water flow analogy is right or wrong (within the limits that all analogies face) or useful is completely independent of the sign of charge assigned to the electron. If anything, assigning it a positive charge would have only strengthened the attractiveness of the water analogy because now you would the electrons flowing from positive to negative potential.

 

where do you find schematics with arrows for direction of current flow? I have never seen them.

Many years ago I found it easy to remember that the heated cathode in a valve (tube) emitted electrons - so that's which way electron flow goes.

Its also easy to remember that the solid state diode symbol arrow points in the direction of "conventional" flow.

 

I don't use the terms 'anode' and 'cathode' enough to have them instantly straight in my mind, so when I need to use them (usually in situations like dealing with a common-cathode or common-anode circuit) I just think of the "cathode ray tube" and since I know that "cathode rays" are actually electrons, I know that electrons are emitted by the cathode. Then I picture the diode symbol as representing the cathode plate with a spread of electrons emanating from the center of it and spreading out toward the anode. At one time I thought it through exactly that way, but today I just briefly think "cathode ray" and that's enough.

 

I see the following defined currents in the diagram: Ia, Ib, Ie, If

These all appear to be defined such that positive current is current leaving the positive terminal of the respective supply, consistent with the flow of charge (i.e., conventional current).

The two unlabeled currents, #62 and #74, appear to be ion streams and I'm guessing (not sure that I understand the process completely) that they are positive ions flowing in the direction of the arrows. Note that they are not labeled as currents.

Correct.
#62 - Ia current loop: + charge proton flow as arc current (#10 -> #20) in ionized gas to the hot cathode (#20) that's heated by the - charge electron flow Ib from the heated filament - charge electron flow If.
#74 - Ie current loop: + charge proton flow as beam current in extracted and accelerated ions in a vacuum chamber to a distant target past the #70 electrode.
(I use proton flow in this case as a deficit of electrons is not positive charge, the charges counted as current are protons)

Conventional current is defined as the Superset of all charge carrier flow directions and is non-physical. It's a great method of teaching by simplifying circuit analysis but a poor method of understanding actual physical processes.

 

Correct.
#62 - Ia current loop: + charge proton flow as arc current (#10 -> #20) in ionized gas to the hot cathode (#20) that's heated by the - charge electron flow Ib from the heated filament - charge electron flow If.
#74 - Ie current loop: + charge proton flow as beam current in extracted and accelerated ions in a vacuum chamber to a distant target past the #70 electrode.

Conventional current is defined as the Superset of all charge carrier flow directions and is non-physical. It's a great method of teaching by simplifying circuit analysis but a poor method of understanding actual physical processes.

Would you agree with the generalized form of Kirchhoff's Current Law which states that the net change in charge within a volume (for us, we'll use "on an object" instead of "within a volume") over some period of time is equal to the sum of the charge flowing onto the object during that time?

Would you agree that if 10 coulombs of charge flows onto this object over a period of 5 seconds that the charge on the object is 10 C more than it was when it started and that the average flow of charge onto the object over that period of time was 2 A?

Would you agree that if -10 coulombs of charge flows onto this object over a period of 5 seconds that the charge on the object is 10 C less than it was when it started and that the average flow of charge onto the object over that period of time was -2 A?

Now let's have the charge flowing onto this object come from two sources as follows:
The object is initially uncharged
An electron beam delivers electrons to the object with a magnitude of |2 C/s| for five seconds.
The object is then left at rest for the next five seconds.
Then a beam of alpha particles delivers helium nuclei to the object, again at a current whose magnitude is |2 C/s|, for five seconds.

What is the total charge on the object from 0s to 15s?

1) Draw a diagram using "electron flow" indicating the direction of the two currents.
2) Draw a graph of the magnitude of all the currents at all times from 0s to 15s.
3) Apply KCL to this system to determine the total charge on the object at all times from 0s to 15s.

For this exercise, let's assume that we can charge and discharge the object this way and ignore the huge voltages that would result using these numbers. We can always scale things to picocoulombs if needed.

 

I'm not disagreeing with you about the results of the calculations but it tells me little about the underlying behavior of how these charges -1 (electrons) and +2 (helium nuclei) as conventional current effect the physical object outside the classroom.

I will admit to a mental bias. I attended navy electronic classes with electron flow in a tube world, unlearn it at school after the service and have worked in industry (semiconductor theory) for 30+ years where the physical movements of charges are a primary concern, most processes involve vacuum where the kinetic energy of particles matter in the equivalent of an electron tube so I'm back to thinking about physical charge movements with current flows.

 

Why is it that I can never get anyone from the "electron current" crowd to answer a question like this. It should be easy.

Let's make it one step easier.

From an electron current perspective, which of the following properly describes the physical movement of charge when an electron beam is fired at the circular object shown?



This is not some trick question. If I were to ask this of anyone from the "conventional current" and ask which is the proper depiction from that perspective, they would say that (b) and (c) are equivalent and either is accurate. According to the E-book and nearly every other source that favors electron current as depicting the "true" current, they would say that the answer is (a). Do you agree?

 

I would ask how is the electron beam deflected in a electric field so I could see the physical movement of the electrons.
http://sun.iwu.edu/~gspaldin/DeflectionByE-field.pdf

 

Also "(i)n practical terms, the ampere is a measure of the amount of electric charge passing a point in an electric circuit per unit time, with an equivalent charge to 6.241×1018 charge carriers (or one coulomb) per second constituting one ampere.[6] Amperes are a measure of flow rate of electric charge." Do note that "one coulomb" is a positive number.

That is the "convention" as used in science and engineering.Thus one coulomb of positive charge moving from A to B constitutes a current of 1 Ampere. Also, one coulomb of negative charge moving from B to A also constitutes a current of 1 Ampere as the signs cancel.

Thus, to be consistent with international standards one would use conventional current flow.

The definition does not state that the charge carriers need to be positive. In fact, the definition is for the amount of charge moving, not the direction or what the charge carrier is.

 

how about the way that electrons move off the cathode of a crt to the screen? repelled by the more negative charge on the cathode to the positive charge on the phospor screen? and focused by the other electrodes. and deflected by the + or- charge on the deflection plates? or by moving through the changing magnetic field of the deflection coils? how about the circuar path of the electrons in the magnetic field of a magnetron? tubes have the electrons emitted by the cathode and attracted by the plate.