I been doing electronics for 45 plus years and never needed a direction sign for current, as it always went from negative to positive, and you simply determined the applied voltage to ascertain the direction.

All this "sign" stuff is just baffling to me.

 

You are being discombobulated by the sign of the flow vector and the sign as a property of the particle.
Ignore the sign of the charge carrier. Instead, say for example, one type of carrier is colored RED and another type is colored BLUE.

RED particles flow from +V to -V.
BLUE particles flow from -V to +V.
Every time a RED particle wants to move, simultaneously a BLUE particle switches place with the RED particle.
The RED particle assumes that it is moving in the positive direction.
The BLUE particle assumes that it is moving in the positive direction.
Because that is the only direction they know how to move, in a positive direction.

Agreed, but even if we had the charges labeled as something that isn’t positive and negative they would still be moving in opposite directions. So let’s say positive charges are blue and negative charges are red. We can only put the positive value for current in the direction of one of these charges (blue). Thus if positive current is in the direction of blue charge even though blue charge isn’t moving, than it follows that a corresponding negative current the other way is in the direction of red charge. With two types of charge moving in opposite directions and positive current one way being equivalent to negative current the other way, only one type of charge can be in the direction of positive current (blue, positive), therefore the other type of charge has to be in the corresponding direction of negative current which is opposite of the direction of positive current (red, negative)? So would it not be valid to say that if we have a negative current from point a to point b with say a value of -5A, than we can say with complete certainty that there are electrons moving from point a to point b (assuming a copper wire system)?

 

I don't mean to be rude, but it's been 18 pages, and counting... I've seen this same exact discussion before, and it's never reached a conclusion that satisfies the parties involved.

We're not even up to 500 posts yet, and already you're grousing? Sheesh...

My question is, why?

An unquenchable desire to do this:

 

I been doing electronics for 45 plus years and never needed a direction sign for current, as it always went from negative to positive, and you simply determined the applied voltage to ascertain the direction.

All this "sign" stuff is just baffling to me.

Hopefully there will be a decision shortly, I cannot finish my current project until I know!
Max.

 

We're not even up to 500 posts yet, and already you're grousing? Sheesh...


An unquenchable desire to do this:

View attachment 211311

Haha I know you guys are annoyed by me and I apologize for that, genuinely was not my intention. And for me it isn’t a dead horse yet. I am just wondering how this isn’t agreeable by everyone: if I label a current from left to right and get a value of -5A why can’t I say that electrons are moving from left to right?

 

I thought it had ended Tuesday evening here: https://forum.allaboutcircuits.com/threads/final-summary-about-current.171023/

Now we seem to be at "Tuesday Morning."

 

Hopefully there will be a decision shortly, I cannot finish my current project until I know!
Max.

Again, I realize this is bothering a lot of people, it’s just something I want to be able to completely understand.

I thought it had ended Tuesday evening here: https://forum.allaboutcircuits.com/threads/final-summary-about-current.171023/

Now we seem to be at "Tuesday Morning."

I posted that since everyone was seeming very annoyed by this thread. That was my final summary which I believed to be all correct, but I did not get any confirmation whether or not it was all correct. The only point of disagreement I seem to be getting still is whether or not you can say that electrons move in the same direction as a negative conventional current. To me it seems that if you have a negative current going to the right than it is perfectly valid to say electrons are going to the right.

 

This is what I posted in that other thread. If someone wants to confirm this summary, I would much appreciate it:

Our typical convention for current, is to say that positive current is in the direction of positive charge movement. There is another convention which says that positive current moves in the direction of electron movement. Is this the correct distinction between each convention(1)?

Within conventional current (I will ignore electron flow convention as not many people use it) I have seen the same statement above as our definition but without the word positive. More specifically, I sometimes see it stated as "current is in the direction of positive charge movement". Is this the same statement as "positive current is in the direction of positive charge movement"(2)? From what I have heard it is the same statement and the word positive is assumed in conversation.

My final question is within conventional current, if you solve for a current in a wire from a to b, and get a negative value, then electrons would flow from a to b, correct(3)? So ultimately conventional current says that positive current is in the direction of positive charge movement, and negative current is in the direction of negative charge movement(4)? I know this last question, people may not typically think of it that way, but would it be technically correct?

I have numbered the questions to make it easier to respond. Thanks so much for the continuous help and community!

 

I thought it had ended Tuesday evening here: https://forum.allaboutcircuits.com/threads/final-summary-about-current.171023/

This thread won't end. Ever.

Now we seem to be at "Tuesday Morning."

More like Ground Hog Day...

 

The flow of electrons in a circuit is often misunderstood. Your electricity supplier does not send you so many electrons per hour.
What you receive is information in the form of an electromagnetic wave.

They wiggle some electrons at the electricity generating station and the light bulb in your house turns on.
The drift velocity of electrons is very small, about 20 μm/s. It means that at 60Hz, electrons wiggled less than 0.1μm each way.

So the end result is we don't really care the color of the particle or which direction they are going. They get a jolt at one end of the wire and the effect is felt at the other end, typically at 60% to 90% of the speed of light (200,000 - 300,000 km/s), or about 3-5ns/m.

 

This thread won't end. Ever.


More like Ground Hog Day...

​

 

The flow of electrons in a circuit is often misunderstood. Your electricity supplier does not send you so many electrons per hour.
What you receive is information in the form of an electromagnetic wave.

They wiggle some electrons at the electricity generating station and the light bulb in your house turns on.
The drift velocity of electrons is very small, about 20 μm/s. It means that at 60Hz, electrons wiggled less than 0.1μm each way.

So the end result is we don't really care the color of the particle or which direction they are going. They get a jolt at one end of the wire and the effect is felt at the other end, typically at 60% to 90% of the speed of light (200,000 - 300,000 km/s), or about 3-5ns/m.

Yes I understand this part, the electrons are already in the wires. It’s not like a power supply is an electron supply. There’s billions of electrons already in the wires. I know we don’t need to know the answer my question to be useful, but why can’t we answer it anyways. If I force some electrons to move from a to b, it is some amount of negative conventional current from a to b. Is this a true or false statement?

 

I can apply a voltage source to a circuit. I can measure current and voltage in the circuit with an ammeter and a voltmeter.
I don't care what is the color of the electron and which way it is moving.

 

I can apply a voltage source to a circuit. I can measure current and voltage in the circuit with an ammeter and a voltmeter.
I don't care what is the color of the electron and which way it is moving.

Okay so just because we don’t care about it or need to know means I can’t ask at all? I know that you, me, and anyone else doesn’t need to know what the electrons are doing, but when my textbook defines current as “current moves opposite electrons” it seems in this case this is equivalent with saying “positive current moves opposite electrons”. So thus it would follow “negative current moves in the same direction as electrons”

 

Okay so just because we don’t care about it or need to know means I can’t ask at all?

No, it does not mean that. Not at all.

What it means is, after flailing away for five damned months at this stupid, trivial issue and constantly begging for clarification of others' statements and/or confirmation of your interpretations, over and over again, it isn't very realistic to expect anyone to put up with the evident futility of continuing to answer you.

You need to ask yourself: "Why, after 5 months in this silly thread, am I still having trouble understanding a simple matter that most people comprehend easily in a matter of minutes-- or even seconds?" You're the only one who's struggling with this; the rest of us aren't.

 

No, it does not mean that. Not at all.

What it means is, after flailing away for five damned months at this stupid, trivial issue and constantly begging for clarification of others' statements and/or confirmation of your interpretations, over and over again, it isn't very realistic to expect anyone to put up with the evident futility of continuing to answer you.

You need to ask yourself: "Why, after 5 months in this silly thread, am I still having trouble understanding a simple matter that most people comprehend easily in a matter of minutes-- or even seconds?" You're the only one who's struggling with this; the rest of us aren't.

I know this is completely my problem and you all understand it, I really just have a couple of small clarification question. Bahn has stated that if you have a current of -10A pointing to the right, than electrons are going to the right. I agree with that statement, and I assume everyone else does. So if I use that to say okay when you have a negative current pointing a certain direction than electrons moves in that direction, I don’t know if everyone agrees with that or not. Bahn seemed to have some issues with my wording. Is my statement correct that if you have a negative conventional current pointing in a direction than electrons are moving in that direction?

I don’t expect anything from any of you, I just hope someone is willing to answer that. If I could repay you all in some way I would, but you all have twenty times the knowledge that I do so I don’t have much to offer.

 

​

 

View attachment 211319​

At this point, all I can do is laugh.

 

View attachment 198938

Using conventional current (the left diagram), if we pick the direction correctly in terms of the direction that charge flows, then the resulting current will be a positive value.

Using electron-current done properly (the middle diagram), if we pick the direction correctly in terms of the direction that the electrons flow, then the resulting current will be a negative value.

Notice that if I were to give you either of the left two diagrams with no label above it, you couldn't tell the difference between choosing conventional versus electron current or just guessing the actual direction of the current correctly versus incorrectly.

But the people that insist on using electron flow almost invariable do NOT do it properly. They would use the right diagram and insist that it is correct even though it results in them needing to use magical mystery minus signs in order to get a positive current to move a negative amount of charge.

If we look back at this. Look at the middle picture. Bahn labeled a negative current from - to + in the direction that electrons move. This is equivalent to a positive current going from + to -. Pictures left and middle are the same Convention and far right is a new convention. So what is the problem with me saying a negative current (conventional) is pointing in the direction that electrons flow.

 

So what is the problem with me saying a negative current (conventional) is pointing in the direction that electrons flow.

Besides being quite obtuse, nothing,