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Author Topic: Flow of electricity - Simple Circuits  (Read 2008 times)
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The physicists, once aware of their basic error invented 'hole flow' so they could continue to believe (in error) that current flows from positive to negative.

I don't even know where to start with how wrong this is.



Bring it on.  smiley-grin Please be aware that the U.S. Air Force has drones available if needed.
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Physicists use Electron Flow
Real people use Current/Traditional/Ben Franklin Flow
I would try and ignore Electron Flow unless you are specifically wanting to get deep into the physics aspect of it.  Or you are trying to do Semi-conductor/material science.

 From my experience that is exactly backwards. I was taught in military electronic training that EE physics teaches and uses the concept of 'conventional' current flowing being positive to negative while we were taught to use that electron/current flows negative to positive. It's an old argument/preference dating back forever to the early discovers of electricity. The physicists, once aware of their basic error invented 'hole flow' so they could continue to believe (in error) that current flows from positive to negative.

 Take your side of the 'argument', but just stay consistent and your circuits will still function. It wouldn't be a problem except the physicists got to define which way the arrow points in semiconductors symbols so as to maintain their original error in defining current flow direction, so all our schematic drawings are wrong.  smiley-wink

No, EE teachers, (at least in the US and at my my university), teach conventional flow.  My various physics teachers over the years would teach either conventional or Electron flow depending on how spiteful they are.  Physics are entirely willing to change their viewpoint for correctness.  Its the engineers who don't due to practicality. 

As mentioned, as long as you are consistent, it should not matter, though your schematic symbols make significantly less sense with electron flow (Look at a Diode, with a triangle with the point in the direction current can flow with conventional).
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The physicists, once aware of their basic error invented 'hole flow' so they could continue to believe (in error) that current flows from positive to negative.

I don't even know where to start with how wrong this is.



Which part?

In the past they believed the flow to be from positive to negative.. until it was proven untrue.

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Manchester (England England)
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From my experience that is exactly backwards. I was taught in military electronic training that EE physics teaches and uses the concept of 'conventional' current flowing being positive to negative while we were taught to use that electron/current flows negative to positive. It's an old argument/preference dating back forever to the early discovers of electricity. The physicists, once aware of their basic error invented 'hole flow' so they could continue to believe (in error) that current flows from positive to negative.
Well do you know how this "mistake" was made? It was from the observation that in electroplating the metals end up being removed from the anode to the cathode. So the reasoning was that the metal was carried by the electricity from the anode to the cathode, not such a daft idea, but in fact with hindsight it was wrong.
Then by studying cathode rays it was realised that electrons in the gas were the carriers of charge. However that only applied to gasses where electrons were the majority carriers.
As theory advanced and semiconductors were explored materials were found that showed charge being transferred from positive to negative just like originally thought. To explain this the concept of the hole was created having a positive charge and incidentally under the right conditions also a positive mass. A hole can be considered as the absence of an electron in the same way you can think about the dynamics of a bubble in soda rather than thing about it as the absence of soda and having to work out the movement of all of the soda round this absence.

So in the end it did not matter at all what way you considered electricity to flow because it flowed in a different direction depending on the material it was flowing in. Therefore there was no need to change anything as there is an equally compelling case for either direction.

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I was taught in military electronic training ......
Yes and they would know I suppose? Sounds like a bit of macho spin on the tale.
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From my experience that is exactly backwards. I was taught in military electronic training that EE physics teaches and uses the concept of 'conventional' current flowing being positive to negative while we were taught to use that electron/current flows negative to positive. It's an old argument/preference dating back forever to the early discovers of electricity. The physicists, once aware of their basic error invented 'hole flow' so they could continue to believe (in error) that current flows from positive to negative.
Well do you know how this "mistake" was made? It was from the observation that in electroplating the metals end up being removed from the anode to the cathode. So the reasoning was that the metal was carried by the electricity from the anode to the cathode, not such a daft idea, but in fact with hindsight it was wrong.
Then by studying cathode rays it was realised that electrons in the gas were the carriers of charge. However that only applied to gasses where electrons were the majority carriers.
As theory advanced and semiconductors were explored materials were found that showed charge being transferred from positive to negative just like originally thought. To explain this the concept of the hole was created having a positive charge and incidentally under the right conditions also a positive mass. A hole can be considered as the absence of an electron in the same way you can think about the dynamics of a bubble in soda rather than thing about it as the absence of soda and having to work out the movement of all of the soda round this absence.

So in the end it did not matter at all what way you considered electricity to flow because it flowed in a different direction depending on the material it was flowing in. Therefore there was no need to change anything as there is an equally compelling case for either direction.

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I was taught in military electronic training ......
Yes and they would know I suppose? Sounds like a bit of macho spin on the tale.

No spin GM, they explicitly covered this in the first couple of weeks of training in the Fundamental DC segment. So while some may not accept it all as fact, it's how they decided to deal with the concept and try to explain a seemingly conflicting definition of what direction does current flow in a DC circuit. And yes they did use some water piping analogies in helping to teach basic ohm's law.  smiley-wink
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So in the end it did not matter at all what way you considered electricity to flow because it flowed in a different direction depending on the material it was flowing in. Therefore there was no need to change anything as there is an equally compelling case for either direction.

 That seems lame to me. Circuits are a combination of components and conductors. Surely something can not be flowing in one direction through a transistor say emitter to collector and somehow reverse direction as it hits the wires going to and from the transistor. There seems to be no questions that something physical is flowing in only one direction in a DC circuit, which is it that is physically moving? 'Holes' are not physical things but rather a lack of something physical.

 My opinion is that 'holes' are a human invention, not unlike religions are, not a physical reality. It's a journey into creative human spin.  smiley-wink 

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So in the end it did not matter at all what way you considered electricity to flow because it flowed in a different direction depending on the material it was flowing in. Therefore there was no need to change anything as there is an equally compelling case for either direction.

 That seems lame to me. Circuits are a combination of components and conductors. Surely something can not be flowing in one direction through a transistor say emitter to collector and somehow reverse direction as it hits the wires going to and from the transistor. There seems to be no questions that something physical is flowing in only one direction in a DC circuit, which is it that is physically moving? 'Holes' are not physical things but rather a lack of something physical.

 My opinion is that 'holes' are a human invention, not unlike religions are, not a physical reality. It's a journey into creative human spin.  smiley-wink  



Holes are a Material Science concept.  Basically it is the lack of an electron where there should be one.  In some materials (mainly a subset of semi-conductors I believe, but I could very well be wrong, this was from a class a few years ago), electrons move by filling other nearby vacant holes.  Thus the 'hole flow'  This is however less efficient than conductors, which work by free electrons moving around freely, rather than moving from vacant hole to vacant hole.  This is what makes Gold and Copper good conductors, while (I think) Carbon or Silicon can be a very good or bad one, depending on what you are doing and how it is doped.

I'm actually fairly surprised the US Military teaches Electron flow.  Its good to know on a material science/semi-conductor level, but I never considered it practical for common EE practices (See Designing, building and troubleshooting circuits).  Its good to know that it exists, why it exists and that it is the actual physical way things happen, but it again never seemed practical to me.
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'Holes' are not physical things but rather a lack of something physical.
Well if something carries charge and has positive mass then in my book it is a good candidate for existing as anything else. The idea of electrons as little bullets is equally as made up.
The thing is that the whole world is stuff we have made up, we have made up the concept electron in just the same way we made up the concept of the hole. We do experiments, do the math and then make up something that fits those two.
We have done well with the made up charge carriers, it allows us to understand how to make transistors.

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Surely something can not be flowing in one direction through a transistor say emitter to collector and somehow reverse direction as it hits the wires going to and from the transistor.
Now you are not grasping the fact that the something is not the same when the direction changes. In metals then electrons are the majority charge carriers but there are still holes. In P type semiconductors where the majority charge carriers are holes there are still electrons. So in ALL circuits electrons flow in one direction and holes in the other. Both are made up and ultimately it makes not a jot of difference which you chose to consider as long as you are consistent.
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'Holes' are not physical things but rather a lack of something physical.
Well if something carries charge and has positive mass then in my book it is a good candidate for existing as anything else. The idea of electrons as little bullets is equally as made up.
The thing is that the whole world is stuff we have made up, we have made up the concept electron in just the same way we made up the concept of the hole. We do experiments, do the math and then make up something that fits those two.
We have done well with the made up charge carriers, it allows us to understand how to make transistors.

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Surely something can not be flowing in one direction through a transistor say emitter to collector and somehow reverse direction as it hits the wires going to and from the transistor.
Now you are not grasping the fact that the something is not the same when the direction changes.  In metals then electrons are the majority charge carriers but there are still holes. In P type semiconductors where the majority charge carriers are holes there are still electrons. So in ALL circuits electrons flow in one direction and holes in the other. Both are made up and ultimately it makes not a jot of difference which you chose to consider as long as you are consistent.

There does not need to be the concept of a hole to support electron flow in metals as it's perfectly possible that a atom with an extra electron (negatively charged atom) in it's valence orbit jumps to an adjacent neutrally charged atom which then becomes negatively charged and the prior atom returns to become a neutral charged atom, no hole required to support this 'electron jumping' in the direction of negative to positive potential. Even in the case of semiconductors it's the electrons that are moved in the direction of 'true' current flow. In a moving car with no ambient wind one may seem to feel that the wind is moving from front to rear of  a moving car if you stick your head out the window, however it's still the car (an electron if you will) that is actually moving in the opposite direction of this 'apparent wind'.
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There does not need to be the concept of a hole to support electron flow in metals
This is true but the fact remains that the flow of charge in a metal can be modeled by the concept of holes, it is just harder. In exactly the same way as you can describe the flow of charge in a P-type semiconductor by using the concept of electrons, it is just that it is harder than using holes. So we use what ever concept is easier to cope with.

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Even in the case of semiconductors it's the electrons that are moved in the direction of 'true' current flow.
I think that encapsulates your problem. There is no "true" direction of current. It is that misconception probably that is driving the military education.
Current is charge flow, there is no true direction. If you consider positive charge carriers it is one way, if you consider negative charge carriers it is the other way. Each is an exact mirror complement of the other and both are something that us humans have made up.
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There does not need to be the concept of a hole to support electron flow in metals
This is true but the fact remains that the flow of charge in a metal can be modeled by the concept of holes, it is just harder. In exactly the same way as you can describe the flow of charge in a P-type semiconductor by using the concept of electrons, it is just that it is harder than using holes. So we use what ever concept is easier to cope with.

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Even in the case of semiconductors it's the electrons that are moved in the direction of 'true' current flow.
I think that encapsulates your problem. There is no "true" direction of current. It is that misconception probably that is driving the military education.
Current is charge flow, there is no true direction. If you consider positive charge carriers it is one way, if you consider negative charge carriers it is the other way. Each is an exact mirror complement of the other and both are something that us humans have made up.

I hear what you are saying, there are three charge states an atom can posses, negative, positive, or neutral and electron movement results in two of these three states potential difference allowing among adjacent atoms. But back to the fact that an electron is a real object that science does acknowledge is a real physical object just as are neutrons and protons are, as well as sub-atomic particles discovered like quarks and the such. While I'm no scientist for sure I've never come across  them mentioning a hole being among the other real physical objects. Unless you claim that really small black holes are flowing inside transistors.  smiley-wink

Holes are a religion.   smiley-wink
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I think you have a misconception that any physicist or EE thinks that holes exist. It is merely a model used to make visualizing what is going on in semiconductors easier.
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Steve Greenfield AE7HD
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I think you have a misconception that any physicist or EE thinks that holes exist. It is merely a model used to make visualizing what is going on in semiconductors easier.

I agree that it's a model that certainly worked to support the impressive development of solid-state electronics I have seen in my lifetime (67 years old in my case). However I have based my comments on the fundamental question of what direction does current flow in all DC circuits, and what is actually moving to support that flow?
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In that case, it depends... ;') Charge flows. Holes are merely a model, a simplification. Because it is far too complicated to use the Standard Model to calculate everything.
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Steve Greenfield AE7HD
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In that case, it depends... ;') Charge flows.
But one can have a charge without flow, as in static electricity, so that doesn't answer the question of what is the direction of current flow and what is actually flowing in a DC circuit wired to a voltage source.
 Holes are merely a model, a simplification. Because it is far too complicated to use the Standard Model to calculate everything.
So do you agree that holes are not real, but rather just a means to explain how solid-state material supports current flow?
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