@chalmersiv - although you will still hear music the sound quality between the two different combinations you mention may be different
If you step up to a higher quality ground wire then the quality will not be impacted
I currently use a high quality 16 gauge silver plated Mil-spec wire for the signal and a reasonable quality 13 gauge (2 x 16 gauge) for the neutral. The sound is extremely good, but that is due in large part to the geometry of the cable rather than the quality of the conductors used.
I have experimented with different combinations of conductor and having a thicker gauge neutral seems to provide a better sounding cable.
Although it would be nice to get away with cable from Lowes, there is no substitute for a conductor made from a reasonably high quality copper
I have also experimented with Romex, 12 gauge Extension cord (from Home Depot), Kimber Kable and the wire in the link above, using various geometries. The cables in the link above provides the best sound quality to date, surpassing all of the various store bought cables I have tried to date
Good comments by Steve (Williewonka). I would add that if the + and - conductors referred to in the OP are not in close proximity, and preferably twisted together in some manner, the inductance of the cable will be considerably increased. If the impedance of the speakers is low at high frequencies (as it is, for example, in the case of many electrostatics), and/or if the cable length is long (inductance is proportional to length, for a given cable type), that may result in perceptible rolloff of the upper treble, and dull or sluggish sounding transients.
Also, in terms of wire quality I would consider the negative conductor to be no less important than the positive conductor. After all, they are conducting the same current, just in opposite directions at any given instant. A conceivable exception to that, however, is that the amplifier might be more susceptible to RFI/EMI picked up by the cable and introduced into its feedback loop (if it has one) from the positive conductor than from the negative conductor.
@almarg - you raise a point that has puzzled me for a very long time
After all, they are conducting the same current, just in opposite directions at any given instant
Granted, the current may be flowing in the opposite direction in the signal conductor, but can the same be said of the neutral?
Is the neutral actually the opposite of of the signal?
When you consider - the neutral conductor in IC's are actually connected to the -ve side of the circuit(s) in the connected components and it's only the signal conductor actually "carrying" the alternating signal, things start to look a little different from the "return path" approach most people are familiar with.
Granted - you do have to have to connect both signal and neutral to both components to "complete the circuit", but is the neutral actually transferring energy that reflects the signal, i.e. except for its opposite polarity?
All of my cables now use different quality conductors, mainly because I have tried using the same conductor for signal and neutral and found it provided no discernible advantage.
Having said that the quality of the neutral conductor I use is quite high
EXAMPLE: in my IC's I use a solid silver signal conductor and a quality copper neutral conductor of approximately twice the gauge of the silver.
Using a copper signal & copper neutral results in a less dynamic sound than the Silver Signal - copper neutral IC, But using a silver neutral with a silver signal provided no benefit over the silver signal and copper neutral IC.
Also, when I think about speaker cables, the "energy" in the signal conductor must be very different from the neutral side simply because by the time the signal gets through the speaker voice coil, most of it has been converted into the movement of the driver, so the neutral must be quite different - doesn't it?
As I said - it has perplexed me for a very long time - even more so since I experimented with cables and experienced my observations.
You raise good questions, which get into some complexities that are not obvious.
"The signal," and the energy that it conveys, is conducted through neither of the conductors. It is conducted in the form of an electromagnetic wave, which propagates at a substantial fraction of the speed of light in a vacuum, and propagates through the dielectric which surrounds the conductors. The exact propagation speed is dependent primarily on what is known as the "dielectric constant" of the particular insulation.
Putting aside reflection effects that can occur mainly at RF frequencies as a result of impedance mismatches, and assuming that the load is essentially resistive, that energy propagates in just one direction, from the source of the signal to the load. However, that propagation of the signal and its energy is intimately related to movement of electrons within both of the conductors, which takes place in both directions (the direction alternating in each of the two conductors, assuming we’re not dealing with DC), and which takes place at an ***extremely*** slow velocity that is referred to as "drift velocity." In the case of electrical signals that are conducted via wires (as opposed, for example, to being radiated through the air or a vacuum), the extremely slow movement of electrons within the conductors and the near light speed movement of the signal and its energy are intimately related, as I said, and one would not occur without the other.
A way to visualize it is that at the instant a signal voltage is applied to the source end of a cable, a **very** slow movement of electrons will occur into one of the two conductors at that end of the cable, and out of the other of the two conductors at that end of the cable, corresponding to the +/- polarity of the signal at that instant. At the other end of the cable, and at all points in between, there will be a similar slow movement of **different** electrons, with the response of those electrons being delayed from the response of the electrons at the source end of the cable by the amount of time it takes "the signal" to traverse the corresponding cable length (at near light speed).
What can be referred to as "the current," as opposed to "the signal," can be considered as corresponding to the number of electrons traversing a given cross-section of a conductor in a given amount of time. One ampere of current, for example, corresponds to one coulomb per second, where one coulomb corresponds to the amount of charge possessed by about 6.2 x 10^18 electrons.
So assuming that only two paths exist between the source and the load, namely the two conductors in a single cable, "the current" being conducted by both conductors in response to an applied signal is in fact identical, except that when it is moving in one direction in one conductor it is moving in the other direction in the other conductor. And in the case of audio signals, or any kind of signal other than DC, the directions in the two conductors alternate between each half-cycle of the waveform.
So with the slight possible exception I mentioned earlier about RFI/EMI pickup, in the case of a speaker cable the two conductors are of equal importance. In the case of a line-level analog interconnect, on the other hand, IMO the "ground" or "return" conductor should if anything be considered to be **more** important than the "signal" or "hot" conductor. The reason being that the characteristics of the return conductor may affect susceptibility to ground loop-related high frequency noise or low frequency hum, depending on the internal grounding configuration and other aspects of the designs of the particular components that are being connected.
So given the foregoing it hopefully becomes clear that your statement that...
... when I think about speaker cables, the "energy" in the signal conductor must be very different from the neutral side simply because by the time the signal gets through the speaker voice coil, most of it has been converted into the movement of the driver, so the neutral must be quite different - doesn’t it?
... is not a correct statement because the transfer of energy to the load goes hand-in-hand with current (movement of charge carriers, i.e., electrons) in **both** conductors. With that movement being equally important in the two conductors, and (putting aside the possible ground loop and RFI/EMI effects I’ve mentioned) being identical in the two conductors aside from being in opposite directions at any instant of time.
Hopefully that clarifies more than it confuses :-)
Steve, when I refer to currents in the two conductors that are equal except that they are moving in opposite directions (i.e., current in one conductor is moving toward the load when current in the other conductor is moving toward the source), another way to look at it, that amounts to saying the same thing but may make it more clear, is that the currents in both conductors are moving in the same direction but around a loop. The loop consisting of the two conductors plus the input circuit of the load plus the output circuit of the source. And between each half-cycle the direction the current is traveling around that loop reverses.
The entire "theory" of the "neutral" is that it, (Shall return the unbalanced load) to the system. And yes it's conductive properties need to be "At least" as functional in resistance as it's positive counterpart. If it is not? And feel free to try this at home! Plug in a lamp with just the "hot" wire. The bulb in the lamp will typically explode. Because there wasn't enough of a path to ground and no neutral. So what happens when you use a lesser cable for your neutral? Unless your speaker is 100% percent efficient. "AND" can use the entire load, It "can" become distortion if there is too much resistance. Of course this should only happen at higher volumes with most systems. I hope this helped.
You raise good questions, which get into some complexities that are not obvious.
"The signal," and the energy that it conveys, is conducted through neither of the conductors. It is conducted in the form of an electromagnetic wave, which propagates at a substantial fraction of the speed of light in a vacuum, and propagates through the dielectric which surrounds the conductors. The exact propagation speed is dependent primarily on what is known as the "dielectric constant" of the particular insulation.
Putting aside reflection effects that can occur mainly at RF frequencies as a result of impedance mismatches, and assuming that the load is essentially resistive, that energy propagates in just one direction, from the source of the signal to the load. However, that propagation of the signal and its energy is intimately related to movement of electrons within both of the conductors, which takes place in both directions (the direction alternating in each of the two conductors, assuming we’re not dealing with DC), and which takes place at an ***extremely*** slow velocity that is referred to as "drift velocity." In the case of electrical signals that are conducted via wires (as opposed, for example, to being radiated through the air or a vacuum), the extremely slow movement of electrons within the conductors and the near light speed movement of the signal and its energy are intimately related, as I said, and one would not occur without the other.
A way to visualize it is that at the instant a signal voltage is applied to the source end of a cable, a **very** slow movement of electrons will occur into one of the two conductors at that end of the cable, and out of the other of the two conductors at that end of the cable, corresponding to the +/- polarity of the signal at that instant. At the other end of the cable, and at all points in between, there will be a similar slow movement of **different** electrons, with the response of those electrons being delayed from the response of the electrons at the source end of the cable by the amount of time it takes "the signal" to traverse the corresponding cable length (at near light speed).
What can be referred to as "the current," as opposed to "the signal," can be considered as corresponding to the number of electrons traversing a given cross-section of a conductor in a given amount of time. One ampere of current, for example, corresponds to one coulomb per second, where one coulomb corresponds to the amount of charge possessed by about 6.2 x 10^18 electrons.
So assuming that only two paths exist between the source and the load, namely the two conductors in a single cable, "the current" being conducted by both conductors in response to an applied signal is in fact identical, except that when it is moving in one direction in one conductor it is moving in the other direction in the other conductor. And in the case of audio signals, or any kind of signal other than DC, the directions in the two conductors alternate between each half-cycle of the waveform.
So with the slight possible exception I mentioned earlier about RFI/EMI pickup, in the case of a speaker cable the two conductors are of equal importance. In the case of a line-level analog interconnect, on the other hand, IMO the "ground" or "return" conductor should if anything be considered to be **more** important than the "signal" or "hot" conductor. The reason being that the characteristics of the return conductor may affect susceptibility to ground loop-related high frequency noise or low frequency hum, depending on the internal grounding configuration and other aspects of the designs of the particular components that are being connected.
So given the foregoing it hopefully becomes clear that your statement that...
... when I think about speaker cables, the "energy" in the signal conductor must be very different from the neutral side simply because by the time the signal gets through the speaker voice coil, most of it has been converted into the movement of the driver, so the neutral must be quite different - doesn’t it?
... is not a correct statement because the transfer of energy to the load goes hand-in-hand with current (movement of charge carriers, i.e., electrons) in **both** conductors. With that movement being equally important in the two conductors, and (putting aside the possible ground loop and RFI/EMI effects I’ve mentioned) being identical in the two conductors aside from being in opposite directions at any instant of time.
Hopefully that clarifies more than it confuses :-)
@almarg One of the best posts I have ever read on audiogon. Your explanation seems logical, takes some of the mystery out of cable theory, and "almost" makes me want to fiddle with cable design. I do appreciate that it is more complex than it seems.
If the audio signal travels through the *dielectric* and not (rpt not) through the metal conductor I suppose we can throw out the whole skin effect idea, which says most audio frequencies travel *inside* the metal conductor at some depth, with only very high frequencies, perhaps above "audio frequencies," traveling near the surface, I.e., skin. How can audio frequencies travel inside the conductor when the audio signal - the electromagnetic wave - travels outside the conductor?
Let’s take the IC connecting two components as an example... - the signal conductor has an AC signal on it - the neutral conductor is connected to the neutral sides of each component
On well designed components the neutral side of the circuit should always be at zero vaults - especially if grounded
If both components are well designed, then the neutral sides of the their respective circuits would be at zero volts,
Therefore, the neutral conductor of the IC should also be at zero volts - yes?
Geoffkait, electric charge still travels back and forth inside of the wire between terminals hence skin effect still applies. It starts for the copper at 20kHz at about gauge 18. Al was only explaining difference between electric charge travelling back and forth (electric current) and energy delivery from source to load in form of electromagnetic wave outside of the cable. Load has voltage drop between terminals hence we have electric field while current in the wire produces magnetic filed. Interaction of these fields causes power draw by the load. Source also has electric and electromagnetic fields that cause power output. As Al stated this energy is delivered in one direction only in form of electromagnetic wave outside of the cable - from source to load. Direction is determined by Poynting Vector. Electric and magnetic fields are perpendicular to each other and determine direction of Poynting vector (direction of energy transfer). It is also true for DC.
Jim (Jea48), Jc4659, and Kijanki, thanks very much for your kind words.
Jim (Jea48), I’m not sure if your most recent post is suggesting that I try to explain why Geoff’s comment is incorrect, or that I refrain from doing so to avoid having this heretofore constructive thread go downhill the way the recent thread on wire directionality has. But I’ll assume the former, perhaps incorrectly.
Geoffkait 8-24-2017 If the audio signal travels through the *dielectric* and not (rpt not) through the metal conductor I suppose we can throw out the whole skin effect idea, which says most audio frequencies travel *inside* the metal conductor at some depth, with only very high frequencies, perhaps above "audio frequencies," traveling near the surface, I.e., skin. How can audio frequencies travel inside the conductor when the audio signal - the electromagnetic wave - travels outside the conductor?
Geoff, to be precise, skin effect means that as frequency progressively increases above a certain frequency (which depends on the diameter of the conductor), "current density" (with "current" defined as in one of my earlier posts) decreases to a greater degree at progressively greater depths. That causes a progressive increase in the resistance of the conductor at progressively higher frequencies.
"Audio frequencies travel inside the conductor," to use your words, in the sense that the movement of electrons, at the very slow drift velocity I referred to, is a very small back and forth oscillatory motion occurring at the same frequency or frequencies for which energy is being conveyed in the electromagnetic wave. As the +/- polarity of the applied voltage changes, at a given frequency, the direction of that slow movement of electrons changes correspondingly. (And actually, to be precise, I should say "net movement of electrons," because random movement of some electrons is always occurring to some degree).
In the recent wire directionality thread which you participated in extensively, Jim (Jea48) quoted a statement by Ralph Morrison, a world renowned authority on such matters, and the author of several textbooks, which contradicts your assertion that the electromagnetic wave travels within metallic conductors. That assertion was also contradicted in another thread here by a noted designer of highly respected world class audio electronics, as well as by me and several other technically knowledgeable posters. During the course of my lengthy career and schooling in electrical engineering I have never seen such an assertion ever made by anyone other than yourself. If you can cite a seemingly credible reference supporting your contention I will attempt to explain why it is either incorrect or is being misinterpreted.
Kijanki, thanks for your characteristically excellent technical input.
Williewonka 8-24-2017 Let’s take the IC connecting two components as an example... - the signal conductor has an AC signal on it - the neutral conductor is connected to the neutral sides of each component
On well designed components the neutral side of the circuit should always be at zero vaults - especially if grounded
If both components are well designed, then the neutral sides of the their respective circuits would be at zero volts,
Therefore, the neutral conductor of the IC should also be at zero volts - yes?
Hi Steve,
First, be sure to keep in mind, as you no doubt realize, that a voltage must always be defined with respect to some reference. Given that, in the example you cite above the neutral conductor would indeed be at or very close to zero volts, **relative to the circuit grounds/signal grounds of the two components.** And probably in most (but not all) designs relative to AC safety ground and earth ground as well. But those facts do not have any inconsistency with what I said in my earlier posts.
Consider the simple example of a 120 volt light bulb. When it is turned on via the switch on the wall, if you were to individually measure the current in the "hot wire" and the "neutral wire" that are connected to it you would measure exactly the same amount of current in both. Even though the neutral wire is at or very close to zero volts relative to earth ground and to AC safety ground.
I’ll take a look at the book you referenced later today or tonight.
Let’s try a different approach. Teflon is obviously a very good dielectric material, right? It has a dielectric constant of approximately 1.0 if I’m not mistaken. Which means that electomagnetic waves will not (rpt not) be slowed significantly through Teflon. On the other hand, we know that the audio signal - which (I think there is agreement on this) is an electromagnetic wave - is found to travel only around 70-85% of the velocity of light in a vacuum. I believe this means that the electromagnetic wave must be traveling through the copper, not the dielectric. His else could you explain the discrepancy?
Jim (Jea48), I’m not sure if your most recent post is suggesting that I try to explain why Geoff’s comment is incorrect, or that I refrain from doing so to avoid having this heretofore constructive thread go downhill the way the recent thread on wire directionality has. But I’ll assume the former, perhaps incorrectly.
As far as the directionality thread is concerned Al and Atmasphere have definitely not proved their points. Furthermore, it should be pointed out much of Al’s argument (as is often the case) is an Appeal to Authority, citing experts to support his argument. Even citing his own expertise, not to mention Atmasphere’s. That’s an appeal to authority. You know, a logical fallacy. Geez, all you would have to do to win any (rpt any) technical argument is say well, I found this guy so and so and he says such and such so I must be right.
Dielectric constant of Teflon is about 2. Vacuum has dielectric constant of 1.
Yes, Teflon will slow down electromagnetic wave. Insulator will slow down electromagnetic wave by amount based on its ability to store energy - Permittivity. Dielectric constant is just relative Permittivity. This speed of electromagnetic wave thru typical insulated wire is about 60% of the speed of light in the vacuum. For typical cable it comes to about 5ns/m and it is exactly true for cat5 cable. There is no different electromagnetic wave for audio signals and other signals.
Thank you, Kijanki. I was just about to post that numerous references can be found on the web indicating that the dielectric constant of Teflon is in the vicinity of 2.0, or even a bit more, not 1.0. Also, the 70-85% figure Geoff cited is of course at best an average or typical propagation velocity, and examples of audio cables having propagation velocities that are significantly slower and significantly faster are easily found.
Steve (Williewonka), the book you referenced looks like an excellent read! I note, btw, that the section your link goes to was authored by Bill Whitlock, of Jensen Transformers, who like Ralph Morrison is a noted authority on such matters. And I note that Mr. Morrison himself is referred to in Mr. Whitlock’s writeup.
Also, if I may be a bit presumptuous, let me extend kudos for your interest in gaining as thorough a technical understanding of such matters as possible, to complement what I know is your very extensive practical experience experimenting with various cable configurations.
Dielectric constant of Teflon is about 2. Vacuum has dielectric constant of 1.
Yes, Teflon will slow down electromagnetic wave. Insulator will slow down electromagnetic wave by amount based on its ability to store energy - Permittivity. Dielectric constant is just relative Permittivity. This speed of electromagnetic wave thru typical insulated wire is about 60% of the speed of light in the vacuum. For typical cable it comes to about 5ns/m and it is exactly true for cat5 cable. There is no different electromagnetic wave for audio signals and other signals.
kijanki,
Can the type of dielectric used cause distortion of an analog signal as it travels through an interconnect? What frequencies, would you say, are affected the most? Example PVC vs Teflon?
Geofkaitt, Yes, it is about 66% = 5ns/m (I inverted it wrong). Teflon is probably a little faster. They also use foam Teflon to lower dielectric constant. In addition wires can be in the hollow tubes since dielectric constant of the air is pretty much the same as vacuum (approx. 1)
Jea48, Dielectric can possibly cause distortion since it absorbs and releases energy. Example of this is capacitor that is charged, discharged by shorting and then opened. Voltage on the capacitor will start growing back from zero to many volts. It is very pronounced in electrolytic capacitors. It happens because dielectric stores and returns energy. It is called Dielectric Absorption and is also related to Permittivity. Returning voltage when signal has already different level can cause distortion. Looking at the lines of audio cable I can say that price is proportional to dielectric used. PVC, that you mentioned is pretty bad while Polypropylene is better, Teflon better yet and oversized tubes of foam Teflon are the best (Acoustic Zen Absolute IC). How much of this is audible I don't know. AZ Absolute sounded "cleaner" to me (more refined), but it can be placebo effect (I expected it). Dielectric Constant also affects capacitance between wires. Capacitance of typical cable is around 25pF/ft while AZ Absolute IC is 6pF/ft. Can capacitance of IC be a source of tiny distortion? Al, what is your opinion on dielectric absorption in audio cables? Can this be audible?
Thanks once more, Kijanki. Your post just above is excellent IMO, as usual.
As far as the audibility of dielectric absorption in audio cables is concerned, my reading of various technical and anecdotal references to that effect I've seen over the years suggests to me that it stands a good chance of being audibly significant in many applications. However I have never seen either an analysis or measured data that would provide a quantitative perspective on it, in the context of audio cables.
So FWIW my own "expectation bias" is in the direction of that effect being great enough in degree to be an audibly significant contributor to cable differences, in many systems. But as far as I am aware information doesn’t seem to be available that would provide insight that is more specific.
Thank you Al. I'm not sure if AZ Absolute ICs are really better in my system or just sound better because of "expectation bias" - either way outcome is the same :)
I would trust your "expectation bias" over some others so called facts any day.
Thank you both for your contributions to this audio forum. I never stop learning from what the two of you have to say. Sometimes I may not fully understand, but eventually it sinks in.
Thank you Jim. Al is known for his knowledge and willingness to help others. He is also much better in explaining things. Al, have you ever been a teacher?
One last thing. Over, I think it is on the Directionality of wire thread, someone posted a link to a largely mathematical article from, I believe it was the Journal of Physics, that described how energy travels down a conductor. The article was used by the posted to support the popular idea that energy travels completely OUTSIDE the wire, not inside the wire. Yet, that very article - in the first couple of paragraphs - states very clearly that energy is traveling both inside the wire AND outside the wire. The mathematics for both energies are subsequently described. I already acknowledged that (some energy travels outside the conductor) might be true a couple of weeks ago. Furthermore, based on that evidence, the mathematical evidence, I hereby declare this current argument a tie. The peer review tribunal can take a break.
Chalmersiv, the answer to your question is of course not predictable with any kind of certainty, in part because cable effects are dependent to a significant degree on the technical characteristics of what is being connected. And in the case of a speaker cable, among other things on how the impedance of the speaker varies as a function of frequency, as well as the nominal impedance of the speaker, and perhaps in some cases also on the amplifier's output impedance and on how much feedback its design incorporates.
But as I mentioned earlier the inductance of a speaker cable can be drastically degraded (i.e., increased) if the + and - conductors are not in very close proximity. Although whatever significance that may have will depend on the impedance of the speaker at high frequencies, and also on the length of the cable. And I note that the description of the T-14 cites low inductance as one of its key features, while the description of the Q-10 does not. That despite the fact that the materials used for their conductors and dielectrics are apparently the same.
So for that reason, together with what has been said earlier about the + and - conductors having essentially equal importance, I would recommend against using any of the cheaper wires you listed for the negative conductors.
What I would suggest that you try, if you already haven't, is using BOTH the T-14 and the Q-10 in parallel. And in each case with the conductors that are enclosed within a given cable jacket being used for BOTH + and - (which if I understand your last post correctly may not have been what you were doing), rather than for just one polarity. Also, I'm not sure if I understand whether your Q-10 is configured with a sufficient number of connections for biwiring, but if not use it in parallel with the T-14 for the bass connections, and use the additional T-14s alone for the mid/hi connections.
On another note: Jim & Kijanki, thanks again for the nice words. Kijanki, in response to your question, no, I have never been a teacher, and I have not ever had any particular desire to be one. But in my career working in a corporate environment I have always found it advantageous to be able to communicate in as clear and precise a manner as possible.
Also, speaking of being knowledgeable, I'll mention that Jim's (Jea48's) knowledge of all things electrician-related continually amazes me. And I've certainly learned more than a few things from his posts over the years. As well as having had the pleasure in various threads here of the two of us successfully resolving more than a few problems people have had with their systems.
Am I the only one that detects a self congratulatory and self serving tone in that last post? Especially in view of the fact he went to such lengths to answer a question he clams he didn’t even understand. More high hilarity on the forum. The fun never stops 😀
Could you please explain in more detail the relationship of the electromagnetic wave, that travels in the space outside of the conductor, (At near the speed of light), and the "current" that travels very slowly slightly vibrating back and forth at 60Hz in the conductor. From what I understand the movement of the current in the conductor is quite slow.... Correct?
The electromagnetic wave is caused by the applied source voltage and the "current", "charge", in the conductor? (Amount of current in the closed circuit determined by the resistance of the connected load. I = E/R)..... Correct?
Am I correct in saying you can’t have the electromagnetic wave without having current? Install an on/off switch in series in the circuit. Close the switch the current passes through the switch contacts through the load and back to source.... Correct?
The bigger the load, the more current in the conductor. The more current in the conductor the larger the electromagnet wave.... Correct? And of course the conductor, wire, must have a current, ampere rating, to safely carry the current in the wire so the wire will not overheat.
IF the wire is too small to handle the amount of current in the wire is it the current that causes the wire to overheat or is it the energy of the electromagnetic wave? Please explain in detail.
.
Not to confuse things, if only a voltage, (potential), is present, an electromagnet field will exist outside of the conductor/s without there being current... Correct?
.
I know it is the energy, from the electromagnetic wave, that makes a heating element heat up and gives off its’ heat into the surrounding air around it. It is not the "current" directly causing the resistance element to heat up.... Correct?
I know the amount of energy consumed,(in watts), by the resistance element is determined by the source voltage and the resistance, in ohms, of the resistance element. E / R = I and we know the current..... Correct?
The Fuse.....
E x I = P
E = voltage
I = Current, amps
P = power, energy, measured in, watts, VA
A fuse rated at 2 amps with a maximum voltage rating of 250V. herman said it is the energy of the electromagnetic wave passing on the outside of the fuse element link that causes it to melt and blow open when the fuse is overloaded.
OK
Isn’t the size, (for lack of a better word), of the electromagnetic wave energy determined by the applied source voltage and the current in a closed circuit? E x I = P. Is not P the energy of the electromagnetic wave?
So say the load is 150 watts and a 2 amp 250V fuse is used to protect the load. The FLA of the 150 watt load is, 150W/120V = 1.25 amps.
Here is where I get hung up. As you know a 2 amp 250V fuse can be used for any voltage 250V or less. It could be used where the voltage is 24V. The ampere rating of the fuse is still 2 amps. So to me the current has to be some component that causes the fuse to blow when the current that passes through the fuse link and exceeds 2 amps in the time curve set by the fuse manufacture. NOTE I did not say current flow.
WOW,... I know,..... I sure have a lot of questions on my mind. Blame herman.
As always you ask good questions. Regarding the first one, though...
Could you please explain in more detail the relationship of the
electromagnetic wave, that travels in the space outside of the
conductor, (At near the speed of light), and the "current" that travels
very slowly slightly vibrating back and forth at 60Hz in the conductor.
... I'm not sure what I can add to what I said in my long post above dated 8-23-2017 at 7:08 p.m. EDT.
Regarding your other questions:
From what I understand the movement of the current in the conductor is quite slow.... Correct?
Correct, assuming "current" is defined as the movement of charge carriers (i.e., electrons in a metallic conductor). An example described in the Wikipedia writeup on Drift Velocity indicates that for a current of 1 ampere in a copper conductor of 2 mm diameter the velocity calculates to 23 um/second ("um" = millionths of a meter). As noted in the writeup, btw, random movement of electrons even in the absence of "current" occurs at a far greater velocity (the Fermi velocity) than the "drift velocity" of current, although the Fermi velocity is still vastly slower than the speed of electromagnetic wave propagation.
Am I correct in saying you can’t have the electromagnetic wave without having current?
Yes, in the case of electrical energy that is being conveyed via wires. Electromagnetic waves can of course propagate in free space, as in the cases of radio waves and light waves.
The bigger the load, the more current in the conductor. The more current
in the conductor the larger the electromagnet wave.... Correct?
Yes, assuming "larger" is interpreted in the sense of having "more energy."
IF the wire is too small to handle the amount of current in the wire is
it the current that causes the wire to overheat or is it the energy of
the electromagnetic wave? Please explain in detail.
The Poynting Vector, which describes the direction in which energy is being propagated, would be perfectly parallel to the conductor if the conductor's resistance were zero. Since that resistance is non-zero, the Vector will tilt slightly toward the conductor, resulting in a small amount of energy being transferred into conductor, absorbed by its resistance, and converted to heat. In effect, the resistance of the conductor causes it to become part of the load.
... if only a voltage, (potential), is present, an electromagnet field will
exist outside of the conductor/s without there being current... Correct?
I'm not 100% certain, but I believe in that situation an electric field would be present, but not a magnetic field.
I know it is the energy, from the electromagnetic wave, that makes a
heating element heat up and gives off its’ heat into the surrounding air
around it. It is not the "current" directly causing the resistance
element to heat up.... Correct?
As I've said, in the case of electrical signals (or power) being conducted via wires the electromagnetic wave and "the current" go hand-in-hand, and one would not exist without the other. So the question is essentially just an academic/philosophical one IMO, not unlike the classical question of whether the chicken or the egg came first.
Your succeeding statements involving E, I, P, etc. are of course correct.
herman said it is the energy of the electromagnetic wave passing on the
outside of the fuse element link that causes it to melt and blow open
when the fuse is overloaded.
It is energy absorbed **from** the electromagnetic wave by the non-zero resistance of the conductor in the fuse, which as I said causes the Poynting vector to tilt slightly toward the conductor, that causes it to blow.
Is not P the energy of the electromagnetic wave?
They are proportional, but strictly speaking energy corresponds to power x time.
Here is where I get hung up. As you know a 2 amp 250V fuse can be used
for any voltage 250V or less. It could be used where the voltage is 24V.
The ampere rating of the fuse is still 2 amps. So to me the current has
to be some component that causes the fuse to blow when the current that
passes through the fuse link and exceeds 2 amps in the time curve set
by the fuse manufacture. NOTE I did not say current flow.
In my earlier long post I defined "the current" as follows:
What can be referred to as "the current," as opposed to "the signal,"
can be considered as corresponding to the number of electrons traversing
a given cross-section of a conductor in a given amount of time. One
ampere of current, for example, corresponds to one coulomb per second,
where one coulomb corresponds to the amount of charge possessed by about
6.2 x 10^18 electrons.
Since the amount of energy that is absorbed from the electromagnetic wave by the conductor in the fuse and converted into heat (causing it to blow if excessive) is proportional to both the energy that is being conveyed by that wave and to "the current," it is reasonable (and of course far more practical) to analyze the situation in terms of amperes and ohms, rather than in terms of joules (a unit of energy) and Poynting Vectors.
And correspondingly, since in the case of electrical signals (or power) being conducted via wires the slow moving "current" and the very fast moving electromagnetic wave go hand-in-hand (as I've explained), IMO it would be meaningless to think of one but not the other as being the cause of the fuse blowing.
Chalmersiv you should try it , you will be surprise on what you hear, I myself connected four different sets of cable, with different length, I have four systems, for me this system is the most live and dynamic of all my four systems..,maybe I got lucky, but it works.....
... if only a voltage, (potential), is present, an electromagnet field will exist outside of the conductor/s without there being current... Correct?
I’m not 100% certain, but I believe in that situation an electric field would be present, but not a magnetic field.
I would agree, it is an electric field not a magnetic field.
.
Since the amount of energy that is absorbed from the electromagnetic wave by the conductor in the fuse and converted into heat (causing it to blow if excessive) is proportional to both the energy that is being conveyed by that wave and to "the current," it is reasonable (and of course far more practical) to analyze the situation in terms of amperes and ohms, rather than in terms of joules (a unit of energy) and Poynting Vectors.
And correspondingly, since in the case of electrical signals (or power) being conducted via wires the slow moving "current" and the very fast moving electromagnetic wave go hand-in-hand (as I’ve explained), IMO it would be meaningless to think of one but not the other as being the cause of the fuse blowing.
Your second paragraph has to be the logical case. And not just for the "why" the fuse blows. The electrical energy will be greater at 120V than at 24V for a circuit using the same 2 amp fuse for overcurrent protection.
120V x 2A = 240 watts 24V x 2A = 48 watts
240V x 2A = 480 watts
Am I correct in assuming watts is a measurement of electrical energy?
Am I correct in assuming watts is a measurement of electrical energy?
Watts is a unit of power, as you of course realize. Power is a quantity that is defined at a specific instant of time, although its average value over some interval of time can of course be calculated. Energy is defined as the product (multiplication) of power and time, and can be expressed as some number of joules, as well as in various other units.
The electrical energy will be greater at 120V than at 24V for a circuit using the same 2 amp fuse for overcurrent protection.
120V x 2A = 240 watts 24V x 2A = 48 watts
240V x 2A = 480 watts
The power and the energy being conveyed to the load will of course be much greater in the 120 and 240 volt cases than in the 24 volt case. But as I’m sure you realize but others may not, the only voltage that the fuse "knows about" is the one that appears between its two terminals, which when it is not blown corresponds to the amount of current it is conducting times its resistance. In the case of audio equipment operating normally that voltage will typically be a small fraction of a volt.
If and when the fuse were to blow, however, the full 120 volts would then appear across its terminals. Although no current would be conducted then since the resistance of the blown fuse would be essentially infinite.
Relevant to all of this, it’s worth noting that in the detailed specifications that are provided by the major fuse manufacturers, such as Littelfuse and Eaton/Cooper Bussmann, the "melting point" (i.e., the point at which the fuse is nominally rated to blow) is specified as i^2 x t (e.g., amperes squared x seconds). As you of course realize, power into a resistive load = i^2 x R, and i^2 x t is therefore proportional to energy.
From what I understand the movement of the current in the conductor is quite slow.... Correct?
Electric current is a flow of electric charge and not the flow of electrons. (In fluids electric charge is carried by ions and not the electrons). Number of electrons crossing given point defines amount of electric charge (current) passing. Motion of electric charge is usually explained as a row of stacked balls in the tube - when you push them slowly they will move slowly but when you hit the first one with a hammer the last one will respond instantly - that's the speed of electric current (charge). Of course there is plenty of space between electrons but "stacking" is not physical but electrical (electric charge).
As for the energy transfer on the outside of the conductor by electromagnetic wave - without it current in the wire alone would not explain energy transfer, since the same amount of electric charge comes and leaves the load (same current leaves and comes back to power supply). Poynting vector is defined by Electric Field E and magnetic field H. Amount of energy transferred is proportional to magnitude of both fields ExH. Electric field is proportional to voltage while magnetic field is proportional to current. Multiply them and you'll get the power P=V*I (power over time is energy). Current flowing thru the fuse causes voltage drop since fuse has resistance. This voltage drop creates electric field across the fuse - without this voltage drop (fuse resistance equal zero) there would be no electric field and magnetic field (current) alone cannot deliver energy to fuse.
Am I correct in assuming watts is a measurement of electrical energy?
Watts is a unit of power, as you of course realize. Power is a quantity that is defined at a specific instant of time, although its average value over some interval of time can of course be calculated. Energy is defined as the product (multiplication) of power and time, and can be expressed as some number of joules, as well as in various other units.
Well I knew watts is a unit of power and I somewhat understood energy and joules. But I guess I didn’t understand the real differences between the two. I do have a better understanding now thanks to you Al.
.
The electrical energy will be greater at 120V than at 24V for a circuit using the same 2 amp fuse for overcurrent protection.
120V x 2A = 240 watts 24V x 2A = 48 watts
240V x 2A = 480 watts
The power and the energy being conveyed to the load will of course be much greater in the 120 and 240 volt cases than in the 24 volt case. But as I’m sure you realize but others may not, the only voltage that the fuse "knows about" is the one that appears between its two terminals, which when it is not blown corresponds to the amount of current it is conducting times its resistance. In the case of audio equipment operating normally that voltage will typically be a small fraction of a volt.
Quote: "But as I’m sure you realize but others may not, the only voltage that the fuse "knows about" is the one that appears between its two terminals, which when it is not blown corresponds to the amount of current it is conducting times its resistance."
" times its resistance."
I have not ever heard it explained that way before. I honestly have never measured a voltage across the end caps or blades of a good fuse. A blown fuse on the other hand yes, as you stated.
I have measured a slight voltage drop across the fuse holder clips, mostly cartridge fuses. A VD across the fuse holder clips indicates poor contact pressure and or corrosion, poor surface area between the fuse caps and fuse holder clips.
The only fuse I have on hand is a 4 amp slow blow fuse. I have an older model Fluke 87 True RMS multimeter and I checked for resistance across the fuse link end caps. With the meter set on ohms auto first touching the two probes together the meter reads 000.01 ohm. I got the same exact reading checking the fuse. LOL, I even reversed the fuse and got the same reading. (You know who that was for) I have read posts of guys that buy audio grade fuses that say they do indeed measure a resistance across the fuse link end caps.
What you said above does make sense though.
I have a good basic understanding how the electromagnetic wave thingy works, I just need learn the lingo better how to express it.
Me thinks when talking about electrical power issues and electrical safety codes, like NEC, I will stick with the old school way I was taught and have a good understanding of. Besides that is what the majority of people understand. Especially electricians.
As for ICs and speaker cables the old school theory just doesn’t fit the reality of how the audio signal travels from the source to the load.
From what I understand the movement of the current in the conductor is quite slow.... Correct?
Electric
current is a flow of electric charge and not the flow of electrons.
(In fluids electric charge is carried by ions and not the electrons).
Number of electrons crossing given point defines amount of electric
charge (current) passing. Motion of electric charge is usually
explained as a row of stacked balls in the tube - when you push them
slowly they will move slowly but when you hit the first one with a
hammer the last one will respond instantly - that's the speed of
electric current (charge). Of course there is plenty of space between
electrons but "stacking" is not physical but electrical (electric
charge).
Quote from link below.
Electric current is not a flow of energy; it's a flow of charge. Charge
and energy are two very different things. To separate them in
your mind, see this
list of differences.
An electric current is a flowing motion of charged particles, and the
particles do not carry energy along with them as they move. A current is
defined as a flow of charge by I=Q/T; amperes are coulombs of charge
flowing per unit time. The term "Electric Current" means the same thing
as "charge flow." Electric current is a very slow flow of charges,
while energy flows fast. Also, during AC alternating current the
charges
move slightly back and forth while the energy moves rapidly
forward.
Electric energy is quite different than charge. The energy
traveling across an electric current is made up of waves in
electromagnetic fields and it moves VERY rapidly. Electric energy moves
at a completely different speed than electric current, and obviously they
are two different things flowing in wires at the same time. Unless we
realize that two different things are flowing, we won't understand how
circuits work. Indeed, if we believe in a single flowing "electricity,"
we will have little grasp of basic electrical
science.
In an electric circuit, the path of the electric charges is circular,
while the path of the energy is not. A battery can send electric energy
to a light bulb, and the bulb changes electrical energy into light. The
energy does not flow back to the battery again. At the same time,
the electric current is different; it is a very slow circular flow, and
the electric charges flow through the light bulb filament and all of them
flow back out again. They return to the battery.
The term "Electric Current" means the same thing
as "charge flow." Electric current is a very slow flow of charges,
while energy flows fast. Also, during AC alternating current the
charges
move slightly back and forth while the energy moves rapidly
forward.
The
energy does not flow back to the battery again. At the same time,
the electric current is different; it is a very slow circular flow, and
the electric charges flow through the light bulb filament and all of them
flow back out again. They return to the battery.
After reading your post I went back and checked again what I had read. Then I clicked on the blue high lighted "slow" word. And this came up.
The quick answer
Inside the wires, the "something" moves very, very slowly, almost as
slowly as the minute hand on a clock. Electric current is like slowly
flowing water inside a hose. Very slow, so perhaps a flow of
syrup. Even maple syrup moves too fast, so that's not a good analogy.
Electric charges typically flow as slowly as a river of warm putty. And
in AC
circuits, the moving charges don't move forward at all, instead they sit
in one place and vibrate. Energy can only flow rapidly in an electric
circuit because metals are already filled with this "putty." If we push
on one end of a column of putty, the far end moves almost instantly. Energy
flows fast, yet an electric current is a very slow flow.
Then,
The complicated answer
Within all metals there is a substance which can move. This stuff has
several different names: the Sea of Charge, or the Electron Sea, or the
Electron Gas, or "charge." We often call it "electricity," and state
that electric currents are flows of electricity. Calling it
"electricity" can be misleading because many people believe that
electricity is a form of energy, yet charge is not energy, and currents
are not flows of energy. Also it can be misleading because the Sea of
Charge
exists within in all metal objects, all the time, even when the metal
hasn't been made into a wire and is not part of an electric device. If the
Electron Sea is "electricity," then we must say that all metals are
always full of electricity, and that batteries are simply
electricity-pumps. Better to call it by the name "charge-sea," and avoid
the misleading word "electricity" entirely.
During an electric current, the metal wire stays still and the sea of
charge flows along through it. When the flashlight switch is turned off
and the lightbulb goes dark, the charge-sea stops moving forward. Even
though it stops moving, the charge-sea is still inside of that wire. If
the flashlight is again turned on, but then two light bulbs are connected
in
parallel instead of one, the electric current will have twice
as large a
value, and twice as much light will be created. And most important, the
charge-sea within the battery's wires will flow twice as fast. In other
words, the speed of the charges is proportional to the value of
electric current; small current means slow charge-flow, large
current means
high speed. Zero current means the charges have stopped in place. Note
however
that an electric current does not have just one speed within any circuit.
Charges speed up whenever they flow into a thinner wire. The high current
in a large flash-lantern's lightbulb will be much faster than the same
current in the other conductors in the lantern. Even though an electric
current is a very slow flow of charges, we can't know the actual speed of
flow unless first we know the thickness of the wires, as well as the
*value* (the amperes) of the current in the wires.
Quote:
"In other
words, the speed of the charges is proportional to the value of
electric current; small current means slow charge-flow, large
current means
high speed. Zero current means the charges have stopped in place. Note
however
that an electric current does not have just one speed within any circuit.
Charges speed up whenever they flow into a thinner wire. The high current
in a large flash-lantern's lightbulb will be much faster than the same
current in the other conductors in the lantern. Even though an electric
current is a very slow flow of charges, we can't know the actual speed of
flow unless first we know the thickness of the wires, as well as the
*value* (the amperes) of the current in the wires. "
And then he says,
The speed of electric current
Since nothing visibly moves when the charge-sea flows, we cannot measure
the speed of its flow by eye. Instead we do it by making some
assumptions and doing a calculation. Let's say we have an electric
current in normal lamp cord connected to bright light bulb. The electric
current works out to be a flow of approximatly 3 inches per hour. Very
slow!
Wow! I'll have to reread it again tomorrow. But I think he is saying the same thing you said. At least some parts of what he is saying. But not others?
The only fuse I have on hand is a 4 amp slow blow fuse. I have an older model Fluke 87 True RMS multimeter and I checked for resistance across the fuse link end caps. With the meter set on ohms auto first touching the two probes together the meter reads 000.01 ohm.
Jea48, It is all very confusing. AFAIK electric current (as motion of electric charge) in wire moves very fast - close to speed of light. Individual electrons also travel fast at about 1% of the light speed (2000km/s) but they move in different directions. What moves really slow is average speed of all electrons (drift velocity). Back to our analogy with balls stacked in the tube - last ball will start moving the same moment as first ball (they push each other). That's electric charge moving (electric current) at the speed of light.
The "electron drift" IS the electron velocity. Drift velocity is on the order of cm per hour. In other words they, the electrons, are virtually stationary. The "drift velocity" is not (rpt not) the net velocity due to back and forth motion of the electrons. Whatever moves at lightspeed or near lightspeed are photons. You know, the only particles that can - and must - travel at lightspeed or near lightspeed. If you want to say current is an EM wave and therefore comprises photons I have no problem with that. Thus electrons are charge carriers, they are not the charge per se.
"Back to our analogy with balls stacked in the tube - last ball will start moving the same moment as first ball (they push each other). That’s electric charge moving (electric current)."
No, actually that analogy intimates that current travels instantaneously, which cannot (rpt cannot) be true. I mean unless you’re invoking action at a distance. Current moves at *near lightspeed* which means current must be photons, no? The electrons are only charge carriers, they're not (rpt not) the charge per se.
No, it is not. Electron drift is AVERAGE speed of all electrons. Individual electrons move fast at about 1% of speed of light even without electric field (Fermi Velocity).
No, actually that analogy intimates that current travels instantaneously, which cannot (rpt cannot) be true.
Line of balls is simplification of lattice of electrons that is disturbed at one end. As I mention before connection between electrons is not a physical one. Electrons poses electrical charge and repel each other. It takes time for disturbance of the lattice to travel thru wire.
Thus electrons are charge carriers, they are not the charge per se.
Electrons poses the charge - it is called Elementary Charge. There are two forces between electrons - gravitational and Coulomb (electrostatic) force. Gravitational is attractive but is very, very small in comparison to Coulomb repulsive force, that exist exactly because electrons have charge.
How could Drift Velocity be the average electron velocity? That would mean some electrons travel *even slower* than one cm per hour. That’s not a typo. One cm per hour. And it would also mean that no (rpt no) electrons travel very fast. Otherwise, the average velocity would be much higher. If it doesn’t make sense it’s not true. In fact, electrons don't have to move at all for the whole thing to work.
Gentlemen, I believe that at this point we are all on the same page regarding what occurs when an electrical signal propagates. To the extent that there is disagreement I believe it just revolves around terminology, and its interpretation.
Regarding "how could Drift Velocity be the average electron velocity?" I think that if the word "average" is changed to the word "net" we could all agree. At least I hope so. The word "net" in this context implying that random electron movements at Fermi velocity would cancel out of the drift velocity calculation, with electron movement caused by the applied voltage remaining in the calculation.
Also, regarding the mention in the article that Jim quoted to the effect that drift velocity is a function of wire thickness, that is correct, and related specific calculations can be seen in the Wikipedia article on drift velocity I linked to earlier.
Also, Kijanki, thanks for the excellent and very informative perspective you provided a few posts back on the Poynting Vector, E and H fields, etc.
Jim, re your Fluke 87 multimeter, I have an 87V I purchased a couple of years ago, which I assume is a similar but more recent model. Great meter, although certainly not cheap (I think I paid around $375 for it). When the tips of the leads on mine are held together it reads either 0.1 ohms or 0.2 ohms, depending on exactly how the tips are held against each other. I don’t know what the gauge of the leads is, but given that the total length of the two leads is about 8 feet I suspect the lead resistance is a significant contributor to the 0.1 ohms, together with round-off due to the limited resolution.
I previously had a small Triplett model 310 analog multimeter, which was ridiculously inaccurate (e.g. it indicated my AC as being around 95 volts; the Fluke indicates about 118 or 119 depending on time of day, etc). Which was surprising because I had read that many electricians use that particular Triplett model. Guess I just had a bad example of it.
Regarding fuse resistance, you might find the information on page 2 of this Littelfuse datasheet to be of interest. For the 4 amp 250 volt slow blow 6.3 x 32 mm glass fuse which is among the many listed, the "cold" resistance (meaning the resistance with negligible current being conducted) is indicated as 0.0311 ohms. So for a design which puts say half the rated max current through it the voltage drop would be a bit more than 0.06 volts.
Al, sorry, but I prefer to not (rpt not) sign up to your explanation, either. For the same reason, actually, that I gave for not (rpt) agreeing with the drift velocity being defined as the average velocity. I.e., it doesn’t make sense. Please don’t put words in my mouth. If you guys want to agree to that explanation feel free to knock yourselves out.
One thing I will sign up to is that if anything is traveling down the conductor it's photons, not electrons. Free free to concur with comment, concur without comment or non concur.
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