Directional wires/cables

@dlevi67

Thank you for the very thorough demolition jobs!

Stereo equipment is DC, which is a directional current

Of all the stuff written here, this I follow the least, but there are plenty of other contenders!

DC refers to Direct Current, that is to say it only flows in one direction.  Sure, our equipment runs internally on rectified and smoothed DC derived from external AC, but our equipment is fed and delivers AC signals.

AC or Alternating Current flows for a short period in one direction, then reverses direction repeatedly. Analog audio signals are AC, and current flows as a result, in speaker and interconnect cables alike.  Current is the net movement of electrons in a direction.

In a metal conductor, a cloud of free electrons exists, with each electron randomly whizzing about.  When we measure a current, it is because there is slightly more movement of electrons in the other direction - and it is called electron drift and is very slow.  Often you could run faster.

That does not mean the signal is slow!  Newton's balls illustrate this, because a ball impacting on end of a line of balls causes the ball on the far end to fly off, even though the net movement (flow) of the row of balls in the middle is almost imperceptible.

Solid metals form crystal lattices, where all the atoms line up in rows.  The atoms vibrate with thermal energy.  Sometimes an atom is missing (called a vacancy) and sometimes a part row is missing, forming a slip line.  Big bits of metal are formed from many crystals, known as grains, and where these grains join, there is a disorganised mess.  Impurities tend to migrate to these grain boundaries.  Current flow is impeded by such messes.

When a metal is plastically deformed (permanent shape change) bigger crystals break up into smaller ones.  This happens when a wire is drawn, a sheet is rolled, or a shape is forged.  The grains tend to become orientated. The grain structure along a wire will show elongated crystals, compared with the structure across the wire.  It will have lower resistance along the wire than across it.

If the metal is heated sufficiently, grains tend to coalesce again to form bigger structures in a process known as annealing but this rarely happens at normal temperatures (lead does creep very, very slowly because its vacancies can move at room temperature).

Given that speaker and interconnect wires generally carry currents that alternate in direction, I would expect any effect along the length of the wire in one direction to be exactly the same in the other direction along the wire.  The only directional effect is from shielding.

@herman

The AC signal that is transferring energy from the source to the load (amp to speaker for example) is NOT doing so by moving electrons from the source to the load. Electrons are NOT flowing down the wire like water through a hose.

Think about it..The energy will flow through a capacitor which has an insulator in the middle of it. How do the electrons flow through an insulator? 

The energy can travel through a vacuum where there are no electrons, think radio waves.

High frequency AC  waves are commonly sent down tubes called waveguides which are hollow = no conductor = no electrons. 

The amplifier transferring energy to the speaker does it by moving electrons backwards and forwards through the connecting wires.  If the energy was flowing in space, you would not need fat wires and the wire resistance would not matter. Some energy does leak out as electromagnetic radiation but this energy is wasted!  QED.

A capacitor acts as a storage unit for electrons.  Pump some in on one plate, and electrons will depart from the opposite plate.  Then the current will stop unless you pump the other way (that is, reverse the applied voltage). Lo and behold, current flows the other way.  Keep alternating the voltage, and alternating current appears to flow through the capacitor, even though the plates are completely insulated from each other. The higher the frequency, the less impedance the capacitor presents to the flow of AC alternating current although the capacitor completely blocks DC (direct current).  QED

Energy can flow through a vacuum as electromagnetic radiation (light, X-rays, infra-red heat, radio waves, microwaves, etc) which vary from each other only in frequency.  Energy can also flow in a vacuum as electron streams (think the old cathode ray TV sets, vacuum tubes, electron microscopes).  So what?  QED

At very high frequencies, most of the current flows at the surface of a conductor because of the skin effect.  The effect becomes important at radio frequencies: at mains frequencies in copper the skin is about 10-mm thick!  Consequently for high frequency transmission, there is little reason to fill the centre of a conductor with expensive metal.  Instead the energy is carried by electrons flowing at the surface of the hollow tube.  However, there is a conductor and there are electrons flowing.  QED

@jea48

I think the answer is instantly. The switch is opened, Games over.

This was in response to what happens when a light is switched off, and of course the answer given is so wrong on so many levels!

When the light is on, it is because power is delivered in an electrical circuit featured by voltage and current - likely to be direct current in a car or alternating current in a home. When the current is suddenly interrupted because the switch is thrown, electrical pressure builds up at the switch. This pressure is known as voltage. If the current was big enough, the voltage becomes high enough to ionise the surrounding air and cause sparks at the switch contacts.

This is precisely the phenomenon used by older car ignition systems to generate very high voltages from 12-Volt DC electrical systems.

On another level, the light will keep generating light as the current it receives slowly dies away. High power incandescent lamps will still be hot enough to shine for a while after receiving no power at all.

Albert Einstein would assert that nothing can travel faster than the speed of light in a vacuum. It would take at least that long for the signal from the switch to reach the bulb. He would also say that there is no such thing as a single instant. Time is relative to where you are and how fast you are moving. Your ’instant’ is different to mine! But you claim to know all this stuff?

@rodman99999 

Were it the DC voltage/current, from an amp's power supply, modulated by the amp's output devices, into an amplified musical signal; it would appear much more complex, but: still a sinusoidal wave

The musical signal is more than a sinusoidal wave, otherwise it would not be considered musical!  We talk of the harmonics that make say a flute sound like a flute, or an electric guitar sound like the distorting amplifier it is connect to.

Fourier theory has it that any repeating waveform or musical note can be represented as an infinite sum of sinusoidal waves, being the base frequency plus all the possible harmonics or overtones.  You can create a graph of the frequency spectrum of the note, although the original note exists entirely in the time domain.

You can apply a mathematical Fourier transform to convert the time domain into the frequency domain, and back again (but not perfectly).

This idea is so pervasive that many audiophiles speak and think in the frequency domain - the treble does this, the midrange does that, and the bass something else.

The only thing I can think of in nature that converts the time domain to the frequency domain is our ear / brain system, which fires complex patterns of neuron activity where the original neurons which fire respond to particular frequencies, but fire at rates depending on loudness.  The initial firing pattern depends on arrival patterns in time.

There are a couple of issues.  Obviously we do not hear high frequency harmonics above say 20-kHz.  To reconstruct sharp transients (for example square waves) very high frequency harmonics are needed to capture the leading edge.  And mathematically without these high frequencies the Fourier transform wobbles before and after the leading edge.  As more higher frequencies are added, a spike appears extending the leading edge.  Ouch

@rodman99999

Thanks, your reference https://www.allaboutcircuits.com/video-tutorials/applications-of-sinusoidal-signals/ has a nice illustration of what I described as square wave wobbles - relevant for digital signals.

This article explains and animates what a sinusoidal or sine wave is: Sine wave - Wikipedia and covers Fourier analysis amongst other things.

Albert Einstein would describe @jea48 ’s hypothetical "instantaneous" light switch's behaviour as impossible "spooky action at a distance". Quantum entanglement has not proven that information can travel faster than light - at least, not yet!

@rodman99999 

Were ... the DC voltage/current ... modulated ... into an amplified musical signal; it would appear much more complex, but: still a sinusoidal wave

Your article about sinusoidals did not actually define what they are!  They are pure sine waves.  Musical signals are not a pure sine wave as you stated.  However, any periodic wave can be mathematically represented by an infinite sum of sine waves  each having a wavelength which is an integer fraction of the target wave.

Explanations work best when the terms are used correctly.

@rodman99999

That particular phenomenon (second paragraph in above article) has been accepted by Physicists, for decades

Almost a century, in fact!  But quantum entanglement has no practical applicability to music reproduction today.  It may in the next few years feature in a class of computing that is not based on binary logic, that may be useful for solving some problems. 

It has never been demonstrated (to this point) that it can be used to communicate faster than the speed of light.  To quote Wikipedia 

However, despite the fact that entanglement can produce statistical correlations between events in widely separated places, it cannot be used for faster-than-light communication.^{[10][11][12]: 453}

@jea48

I seem to recall that in another post you said you learnt your electricity from this forum? Could I suggest reading a couple of recognised textbooks? Also, science advances when researchers publish peer-reviewed papers in scientific periodicals, which other researchers can cite in their work, or can challenge. By all means, read widely but for goodness sake, don’t quote indiscriminately.

So you are saying in a closed circuit the signal flows back and forth from the source to the load. Correct?

Almost. The signal is the voltage, which is analogous to electrical pressure caused by a slight excess or deficit in the balance of protons and electrons. Apply a voltage to one end of a wire, and almost immediately (depending on inductance) the voltage becomes uniform along the wire, including at the far end. If you make the voltage oscillate at one end, it oscillates at the other end. You don’t even need a circuit, though there is an almost imperceptible average movement of electrons when the applied voltage changes.

There is a slight time delay, which Quad make use of in their electrostatic speakers. They want to simulate a point source of sound a foot behind the panel. If you imagine sound radiating from that point, it reaches the centre of the panel first. then radiates outwards in rings. Quad delays the voltage signal to concentric rings using 12 miles of wire wound into inductive coils.

If the source is a CDP and the load is an Integrated Amp, using only one channel, the signal leaves the output on the hot wire of an IC, flowing back and forth, flowing to the input of the Amp, through the input circuit of the preamp, and then returns on the return wire back to the CDP output... Correct?

Vaguely. The source is a CD Player, so it outputs a line-voltage analog signal at audio frequencies, say 20-Hz to 20-kHz. The peak to peak voltage swing is around 1 Volt. Your interconnect (to me, IC also means integrated circuit) looks like a two-wire with RCA connectors rather than a 3-wire balanced connection, so there is a circuit. The amplifier presents an impedance (usually very high) so provides a path for some current to flow. The current flows out on one wire and back on the other. When the voltage reverses, the current reverses. The amplifier and the player could be designed so the current is regarded as the signal but almost universally, voltage is used as the signal instead.

As for the current the "net movement" of charge, it will measure the same on the hot wire as the return wire in the IC back to the analog output section of the CDP. Correct? This whole event takes place in the wires... Correct?

Correct. The current flows in the wires. This is not the whole event though! The current creates a magnetic field outside the wires. Changing magnetic fields create changing electrical fields - the foundation of electromagnetic waves. Note that these waves are not made of charged particles like electrons!

How does the input section in the preamp, for a better word, extract the signal from the IC as it travels through the closed circuit, flowing back and forth, back to the CDP? And what happens to the signal that returns back to the CDP?

Wow! Is that how you are saying it works?

The job of the amplifier is to take the AC input voltage signal (about 1-Volt maximum peak to peak) and increase the voltage enough to drive the speakers at the desired volume. A typical amplifier will have DC power supply rails at several 10s of Volts, plus and minus. The first amplifiers were based on triode valves, where a small voltage applied to one electrode allowed big currents to flow from the DC rails through the speakers.  Later the bipolar junction transistor (BJT) and the metal–oxide–semiconductor field-effect transistor (MOSFET) were deployed.

Amplifiers just have to raise the output voltage to some multiple of the input voltage. Would be easy if those pesky speakers stopped allowing big currents to flow! Big currents cause a voltage drop according to Ohms’s Law, making it harder for the amplifier to get the output voltage where it should be.

Energy is what makes the light bulb light, not the current. Current is not consumed by the load. Proof, it returns to the source. Current measures the same on both sides of the load.

Energy is not consumed, it is transferred. It does not return to the source.

Where do I start? Overall, in our universe energy is conserved, so the light bulb converts some electrical energy into heat, some of which is converted into light. The energy comes from the power supply.

Power is usually measured in Watts and is calculated as the current times the voltage drop. Without current there is no electrical power. Electrical energy is power times time.  It is usually measured in Watt-hours or kiloWatt-hours. In our light bulb circuit, current is conserved but the bulb consumes power as the voltage drops across its filament which has resistance. Ohm’s Law applies here as well as in speakers.  Know any two of current, voltage drop and resistance and you can calculate the remaining quantity and the power.

Do things in the white paper sound familiar? Is Ian M. Sefton wrong too?

Yes they sound familiar but only because you keep repeating them ad nauseum! Yes, he is wrong. "The things the text books don’t tell you"  contains things the text books don’t tell you because if they did, the text books would be wrong. I debunked his five major assertions in detail earlier. I marked each response QED, which coincidentally is the name of the maker of my main stranded, silver-plated copper speaker cables. They are spirally twisted around air-core tubes. Finally on-topic!

Ian M Sefton makes me ashamed to be an Australian,.really ...

For those who find it hard or impossible to visualise how a signal can travel faster than the stuff it travels through, consider how sound reaches your ears from a loud speaker.

Air comprises molecules randomly whizzing about in all directions, and sometimes colliding with each other and the surroundings. When the speaker cone moves forward, some of the nearby molecules get a slight extra shove in the forward direction.  They pass this extra shove to the molecules near them, and so on.. The extra shove reaches your ears at the speed of sound, but no molecule has to directly travel from the loudspeaker to your ear, let alone at the speed of sound  There is no need for a sonic jetstream, 

This is similar to the behaviour of the cloud of free electrons whizzing about in a metal, responding to a voltage signal.

Or think of a long train (our record in Australia is 4.5 miles long with 682 cars and 8 locomotives), The couplers between the cars are designed to have a small amount of slack so overall the train stretches when pulled and compresses when braked.  Imagine the train is stopped.  Apply power to the lead locomotive, and the coupling to the next car will stretch a bit before that car starts to move.  The process ripples down the length of the train.  After a short while, the signal that the train is moving arrives at the last car (a mile or more from the loco) though overall not one of the cars has moved more than a few yardsl.

@jea48 

I learned in 2010 what I was taught in K thru12 was wrong how electricity works.... Four years of electrical apprenticeship training I was taught the same wrong crap

Nevertheless, it would be helpful if you could remember how to apply Ohm's Law, and how power is calculated in electrical circuits!  Fortunately, when wiring houses, you don't need to work things out from first principles, because engineers have done this for you and experts have written building codes to follow.

My partner's son leads a crew working on high voltage transmission lines running hundreds of thousands of Volts, but in Australia he is not officially qualified to install a 240-Volt outlet in his own home!  That would be against government regulations.

Talking of government, a while ago I sold an upgrade to The Canberra Hospital's digital imaging system, which was the source of all patient records.  I included a big uninterruptible power supply (UPS) with rectifiers, batteries and inverters.  The hospital insisted that their own electricians do the installation.  When I inspected the finished system, there was a computer room with hospital grade power outlets, red for the high-availability outlets, beautifully run back through a distribution system to the UPS.  But the UPS only had one cable connected - the output.  The electricians (we call them sparkies in Australia) had "forgotten" to run mains power to the UPS.

@jea48 

I see you didn't bad mouth Ralph Morrison. 

Ralph Morrison What is Electronics

"If we accept the idea that fields carry energy in space, it must be true at all frequencies. That is the law. If it is true for light, it must also be true for 60Hz power and at DC. For utility power, the energy travels in the space between conductors, not in the conductors. This is not the picture presented by circuit diagrams, where energy seems to be carried by conductors. In digital circuits, the signals and energy travel in the spaces between traces or between traces and conducting surfaces.

Buildings have halls and walls. People move in the halls, not the walls. Circuits have traces and spaces. Signals and energy move in the spaces, not in the traces."

No, I could not be bothered but I will have a little crack at him now!

If it is true for light, it must also be true for 60Hz power and at DC.

Light is an example of electromagnetic radiation which can be visualised in classical physics as synchronised oscillations of electric and perpendicular magnetic fields.  In a vacuum, they travel at the speed of light.

They are reinterpreted in quantum physics as streams of photons, which are uncharged particles with zero mass when they are at rest.  Photons do not obey the Pauli exclusion principle.

In this context, 60-Hz power and DC surely refer to electricity?  60-Hz electromagnetic waves are very low frequency radio waves!  DC is not any sort of wave.

Electricity is the result of charge, and charges are carried by electrons and other particles which do obey the Pauli exclusion principle.  Similar charges strongly repel, and opposite charges strongly attract.  Richard Feynman has stated that every electron affects every other electron in our universe.

Electric currents are not a form of Electromagnetic radiation - Wikipedia.  Mr Morrison is confusing photonics and electronics (electricity in particular).  Having got that fundamentally wrong, his assertion that electrical energy is carried in the spaces between conductors is equally wrong.

His speciality seems to be circuit board layout for digital circuits.  His message is to beware of interference between adjacent traces, especially in multi-layered applications.  This is good advice, not because of electromagnetic radiation, but because every electron interacts with every other electron.  (Photons are much better behaved!).

In digital circuits, the signals and energy travel in the spaces between traces or between traces and conducting surfaces

Surely traces are conducting surfaces?

The circuit board traces are the conductive halls filled with crowds of free electrons.

Finally, digital circuits typically operate at or near Gigahertz switching rates.  The skin effect is very important at these rates.  Almost always the switching is done in integrated circuits based on doped semi-conductors, not conducting metals.  The quantum properties of the electron turn this subject from electrics into electronics, often at the nano-scale.

If Mr Morrison believes in his "law" he should change his title to "What is photonics"

@jea48 

Did you do your practical hospital wiring based on the "false" teachings from your apprenticeship, or based on what you learned here?  Be honest.

Maybe you were the sparkie that "forgot" to connect The Canberra Hospital's UPS to the mains supply?

Perhaps you could restate your understanding of electrical energy, as set out below, so it makes sense?  You might care to include the effects of resistance and voltage ... and the relationship between power and energy:

Energy is what makes the light bulb light, not the current. Current is not consumed by the load. Proof, it returns to the source. Current measures the same on both sides of the load.

@jea48 

You seem to accept that

Light is the fastest-moving stuff in our universe. It travels at 186,000 miles per second (300,000 km/sec)

I'd add "in a vacuum" just for completeness.

You would, I hope, agree that low frequency electromagnetic waves are radio waves and travel at the speed of light.

So would you dispute that the wavelength of 60-Hz radio waves in a vacuum is 186,000 / 60 or about 3,100 miles?  That's about the radius of our planet.

Do you really think the conductors in a circuit board radiate any detectable amount of 60-Hz radio waves?

You might care to read up on the difficulty of communicating with submerged submarines using extremely low frequency radio - see Communication with submarines - Wikipedia

@jea48

Thank you for your honesty, You do your wiring the same before and after you ’learnt’ how electricity really works on this forum.

I really don’t think the author needed to say, in a vacuum...

No, but as a physicist I just had to add that nuance before I got accused of getting it wrong! Light slows down in water, glass or plastic by a ratio corresponding to the refractive index of the medium.

In fibre-optic cables, light normally arrives faster if it travels straight down the middle, than it does when bouncing at an angle off the inner surface. This is simply because it has further to travel. So at the end of the transmission, the light is smeared out in time depending on the path it took, which is not good for digital signals

Clever manufacturers use glass with a higher refractive index at the centre, getting lower towards the edges. This is done by changing the composition of glass vapour during vacuum deposition when building up a glass slug. The slug is subsequently drawn into a very fine fibre. The higher refractive index at the centre is designed to slow straight-through photons so the signal arrives all at once, more or less. Obviously this is more important for undersea cables than for component connections, but hey .... if marketed properly some will buy in.

Did you know that space has negative energy? Create more space, and you create more vacuum into which things can "fall". Or that quantum space is not really empty - particles and anti-particles appear and annihilate randomly. That is a credible way to create a universe from almost nothing