directional cables?

Mr Simple, I decided the stuff in my last post about positive charges really didn't relate to your response so I deleted it.

I see what you mean but by defintion current is not the flow of electrons, it is the flow of charge. Since we're talking about cables then electrons are indeed moving about but you don't have to have moving electrons to have electric current since it is sometimes positive charges.
Refer to this http://en.wikipedia.org/wiki/Electric_current

Since the flow of charged electrons is relatively easy to envision it is used a lot, an analogy to water is often used even though it breaks down if you try to apply to all electrical phenomna. To truly understand what is happening you need to move beyond the electron model and think in terms of energy, in terms of electromagnetic waves, in terms of things where the math gets so complicated most people including me can't understand it well enough to even know what it is they are missing. However, I do know enough to understand that electron flow can't explain everything happening in electronics.

Rrog, yes, why would that suprise you? If I am wrong I am willing to admit it, unlike others around here. However, after reading Mr Simple's response I think I may have been correct since he is indeed equating flowing electrons with flowing charge,

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Herman - In addition people believe that since charge flows back and forth (AC) energy does the same and directionality of the cable doesn't exist. Energy flows one direction from source to destination. Some explanation here:
http://amasci.com/miscon/whatdef.html

Companies like Audioquest mark direction on their speaker wires (sold per ft). They claim audible difference since wire was drawn one direction and there is certain "grain" of crystals. I would not listen to such claims but I remember that copper oxide is a semiconductor. I believe they know more than I do.

Mr Kijanki, now you've done it. Since you started talking about transferring energy some are going to throw you into the same idiot pile that I'm in. Much better to talk about electricity as water in a garden hose so everyone can follow along :>)

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Kijanki

Once again - Electric current is a flow of charge ALONE. At 1kHz electrons are practically standing still (vibrating +/-0.0001mm) NEVER MOVING ALONG THE CABLE while charge is reaching destination with almost speed of light (0.6-0.7).
Electrons might be carriers and you can calculate numbers from amperage but they don't "Flow" - charge does.

Once again, and with all due respect, you don't know what you're talking about.

In a piece of wire, it is the electrons that are the charge carriers. Therefore you cannot have a flow of current without a flow of electrons. The two cannot be separated.

With no current flowing, yes, the electrons are just banging around randomly due to the thermal energy in the wire (the lattice vibrates, knocking the electrons about). And at any given point, the number of electrons crossing that point are effectively the same in one direction as the other.

Now, if you apply a potential difference to one end of the cable, and assuming there is a load at the other end and it's not just an open circuit, while the electrons will still be banging about, they take on a net drift in the direction determined by the polarity of the potential at the other end and you now have a flow of current as there are now more electrons crossing that point in one direction than are crossing in the other direction.

And while the net drift is typically very slow (on the order of centimeters per second), that's simply a function of how much current is flowing and the number of electrons available to participate in conduction.

Keeping all else equal, increase the potential and you increase the current and subsequently the drift velocity. Similarly, if you increase the number of electrons available to participate in conduction, you decrease the drift velocity.

What propagates at nearly the speed of light is the transverse electromagnetic WAVE that's established once the potential difference initiates current flow. And this I think is the crux of your misunderstanding.

You say "..while charge is reaching the destination at almost the speed of light..."

This is incorrect. The charge is already at the destination. Again, it's the electrons that are the charge carriers. There are electrons throughout the entire current loop. It's just that those electrons at the end don't start to flow until the electromagnetic wave reaches the end.

Herman

Mr Simple, I decided the stuff in my last post about positive charges really didn't relate to your response so I deleted it.

Ah. I didn't know users could edit or delete their posts. Or are you a moderator?

I see what you mean but by defintion current is not the flow of electrons, it is the flow of charge. Since we're talking about cables then electrons are indeed moving about but you don't have to have moving electrons to have electric current since it is sometimes positive charges.

True enough. But since this thread is about cables and posted in the cable forum, I didn't think it terribly germane or productive to discuss electric current outside the context of cables.

Since the flow of charged electrons is relatively easy to envision it is used a lot, an analogy to water is often used even though it breaks down if you try to apply to all electrical phenomna.

Yes. But the issue under discussion is current flow. And the water analogy is perfectly adequate in this context.

However, I do know enough to understand that electron flow can't explain everything happening in electronics.

For example?