Electric Current, DC circuit, which one.

Discussion in 'General Electronics Chat' started by Mac Rodriguez, May 1, 2016.

why is ELECTRIC CURRENT positive charge flow instead of negative charge flow.

0 vote(s)
0.0%

0 vote(s)
0.0%
1. Mac Rodriguez Thread Starter Member

Mar 24, 2016
101
8
I don't understand why if by the popular definition the ELECTRIC CURRENT is the bumping/flow of a charge from point A (- black/+ red) to B (load) to C (+red/- black) in a DC circuit and through a wire only electrons with their attached ELECTRIC CHARGE are the only ones that can move , then what is it that everyone means when they say that CONVENTIONAL ELECTRIC current is the real current. Protons don't move through a wire; I mean the protons charge might be able to move through the wire but not the proton, in opposite view the electron can and does move with it's charge. So the how could the ELECTRIC CURRENT be conventional if all that is is positive charge.

Jul 18, 2013
10,838
2,512
The difference with conventional flow and electron flow is the former indicates a flow from pos to neg, the latter is the actual direction of electron flow from neg to pos, and has been attributed to Ben Franklins error in naming the conventional way.
Max.

Tonyr1084 likes this.

Sep 22, 2013
2,178
419
4. Mac Rodriguez Thread Starter Member

Mar 24, 2016
101
8
That thread didn't didn't much except for this picture

Alright, so here we have it. A DC circuit with a diode in the middle. The way it was explained to me through articles is that the Amperage I.e. current goes from the - to the + BECAUSE the - electron charge ( in the quantity of a Coulomb i.e. 1 Coulomb = 1 Amp) bumps/flows from the - to the diode allowing it to flow out and not return back and then continue to the +. BECAUSE the electron with it's attached charge is the only one that can move through the wire. The + terminal cannot send protons out it's terminal or electrons. And if it did send electrons out of it's terminal it would be stopped by the diode.

Yes I am aware of the history, but it still does not explain or answer the confusion about the ORIGINAL DIRECTION from where the ELECTRIC CURRENT moves from/out-of.

Last edited by a moderator: May 2, 2016
5. #12 Expert

Nov 30, 2010
16,679
7,321
The definition of convention is, "an agreement among people". Conventional flow is just an agreement among people so they can understand each other. Electrons, power, and charge don't have to understand or agree. They just do what they do and people call it, "flow". You can believe in electron flow or conventional flow. Just declare which one you're using so you will be understood.

6. Mac Rodriguez Thread Starter Member

Mar 24, 2016
101
8
I want to BELIEVE the TRUE flow.
Let's PRETEND that current always flows from the - to +. And pretending this then one can not place a diode in the OPPOSITE direction of this picture

because it if did the diode would be useless because the check valve (diode) would not let any electric current flow (electrons) through from the start ; and pretend there is a light bulb behind the check valve, and would not let the bulb light up. So if electric current flows from - to + then the picture should not say " not quite right " and instead say " quite right "

7. #12 Expert

Nov 30, 2010
16,679
7,321
It is my opinion that electrons flow.
Else, how would vacuum tubes work?
I don't have the power to make anybody else believe me and I surely don't have time to resolve over 1000 Threads into one answer.
I say electrons flow.

Jul 18, 2013
10,838
2,512
My Electronics instruction started in the valve era so I was taught right off the bat about the phenomenon of the electron boil off from the -ve cathode and the flow to the +ve anode.
The diode check valve symbol conforms to the 'Conventional' flow.
Max.

9. BR-549 Well-Known Member

Sep 22, 2013
2,178
419
I can't answer your poll, because the answer is both. Current starts at both ends. On can't flow one without the other.

Physical current always flows from - to +. This is because only negative charge can move. And since charge is self repulsive, negative charge must move in that manner.

Theoretical, analytical, and/or designing, mathematical and/or instructional current is always from + to -.

It's purpose is to not confuse mathematicians..............but it confuses everybody else.

It's a regular question here.

Mac Rodriguez likes this.
10. Mac Rodriguez Thread Starter Member

Mar 24, 2016
101
8

Alright so far it sounds like everyone is getting stuck at the part where current is subject to the flow of charge and how it can be either one. But ELECTRICAL ENERGY is transported in the charge that is in/on/with it's CARRIER! The carrier of charge with ELECTRICAL ENERGY in a metal wire through a DC circuit is the ELECTRON because it's the only carrier that moves through out the circuit. Protons don't move through a wire so what carrier does CONVETIONAL CHARGE have to take it to X load.

How could this be

wouldn't the diode stop the electrons and their charge from continuing to flow and then stopping the electrical energy from reaching the bulb to light up. Isn't that what a DIODE IS MADE TO DO.

Last edited by a moderator: May 2, 2016
11. crutschow Expert

Mar 14, 2008
13,488
3,372
You can't mix conventional current flow with electron flow.
Pick one or the other, otherwise you will just confuse yourself.
The electrons are the actual carriers in a metal conductor, but which you choose has no effect on circuit calculations as long as you consistently stay with one polarity for the carriers.
I like to use conventional current flow since the current then flows from top towards the bottom in typical circuit schematics that have the positive supply on top, and also the current flows in the direction of the arrows on diode and BJT symbols.
Electron flow is in the direction opposite of the arrow direction.

The primary place that positive current flow doesn't work is in trying to explain the flow of charges in vacuum tubes and semiconductors.

Incidentally the "mistake" made by Franklin was simply because he did not have the tools to determine what the actual charge carrier polarity was, so he arbitrarily assigned them to be positive. The actual polarity was not determined until the end of the 19th century.
He had a 50-50 chance of getting it right, and as most of us know from experience, if you have a 50-50 chance of making a mistake there's a 99% chance you will make it.

Tonyr1084, Sinus23 and BR-549 like this.
12. Mac Rodriguez Thread Starter Member

Mar 24, 2016
101
8

Placed within a battery/lamp circuit, its operation is as such:

When the diode is facing in the proper direction to permit current, the lamp glows. Otherwise, the diode blocks all electron flow just like a break in the circuit, and the lamp will not glow.

If we label the circuit current using conventional flow notation, the arrow symbol of the diode makes perfect sense: the triangular arrowhead points in the direction of charge flow, from positive to negative:

On the other hand, if we use electron flow notation to show the true direction of electron travel around the circuit, the diode’s arrow symbology seems backward:

The primary place that positive current flow doesn't work is in trying to explain the flow of charges in vacuum tubes and semiconductors.

This is from AAC. And yes it's confusing like you said.

13. BR-549 Well-Known Member

Sep 22, 2013
2,178
419
Welcome to electronics. There will be other confusions.

Mac Rodriguez likes this.

Jul 18, 2013
10,838
2,512
As @crutschow said, Pick one!
Max.

15. #12 Expert

Nov 30, 2010
16,679
7,321
You see the diode symbol as an arrow pointing toward a bar. I see it as resembling a speaker symbol. The bar is the driver of the speaker and it speaks electrons out the horn.
See? A little dyslexia can help.

djsfantasi likes this.
16. WBahn Moderator

Mar 31, 2012
18,085
4,917
Electrical current is the flow of CHARGE and not the flow of charge-carriers. When electrons flow in a wire, the charge flows in the opposite direction because the charge that an electron carries is negative. Even the electron-flow proponents agree that an electron is negatively charged (even though that is simply an agreed-upon definition)

Consider the following simple example.

I have Object A and Object B that start out neutrally charged. Then some charge is transferred at a constant range for a period of 2 seconds from one to the other such that Object A has a charge of -6 coulombs and Object B has a charge of +6 coulombs. During the period that charge of flowing, what was the current and in what direction did it flow? The answer is simple. In 2 s, 6 C of charge flowed from Object A to Object B, thus the current was three coulombs/second from A to B and since one coulomb/second is defined as one ampere, this is the same as saying that a current of 3 A flowed from A to B. This is equivalent to saying that we had a current from B to A of -3 A.

Note that no where in this was it important or relevant to even mention the nature of the charge carriers. What if the charge carriers were electrons that physically moved from Object B to Object A? So what if they were? Electrical current is about the flow of CHARGE, not charge carriers, so you still end up with a current from A to B of three amperes! The total charge moved by the electrons from B to A is NOT six coulombs, it is negative six coulombs. Thus the current from B to A is NOT three amperes, (-6 C)/(2 s) or -3 A, which is equivalent to a current from A to B.

The people in the "electron flow" crowd are almost never self-consistent. They would say that there is a current of 3 A from B to A, yet at the same time maintain that this flow of three coulombs per second onto Object A somehow results in the Object A having six coulombs LESS charge after two seconds! How is this possible? It isn't -- unless you throw around a bunch of magical mystery minus signs in order to make things come out the way that you want them to, which is exactly what they end up doing.

Last edited: May 1, 2016
kubeek and Mac Rodriguez like this.

Mar 24, 2016
101
8

18. ElectronicMotor Member

May 1, 2016
53
6
When Alessandro Volta discovered a steady flow of current, he decided to define its direction as going from the positive to negative terminals of a voltage source. He didn't know that it was electron flow, and that electrons where later found to have a negative charge. There is little difference between negative electron flow in one direction and possative hole flow in the opposite direction except in doped silicone devices such as transistors, or valves.
Ultimately, the definition of a positive or negative electric field defined whether an electron had an attractive or repulsive force.
Perhaps low tide should have been defined as high tide ? It don't matter, as long as every body agree's.
Hope this confuses.

Last edited: May 1, 2016
19. Mac Rodriguez Thread Starter Member

Mar 24, 2016
101
8
I would if I knew which one was the TRUE one.

20. WBahn Moderator

Mar 31, 2012
18,085
4,917
First, define what "electrical energy current" is?