In an attempt to enlighten the non-believers (those having difficulty understanding currents through voltage sources), let's alter/simplify MH's question to the following:

- same ideal voltage source and ideal 5H inductor connected across each other.
- between t=0 and t=3, V=+4V
- between t=3 and t=6, V=-4V
- from t=6 to infinity, V=0V
(see scope shot)

We know from previous discussions that between t=0 and t=3, the circuit current will ramp up linearly to 2.39A. I think everyone agrees with this, even the non-believers. We can also calculate the power and conclude that the power delivered by the voltage source ramps up from 0W to 9.56W during the same period of time. But since we know that the current and voltage in a voltage source are 180º out of phase, the power will actually ramp down to -9.56W.

What happens between t=3 and t=6 when the voltage inverts from +4V to -4V? Well, the non-believers have stated the following:
But how can that be? Real world experiments certainly don't result in the catastrophic end of the earth, and a simulation debunks this notion as well. Well, the non-believers argue that the L/R ratio of 5000:1 is not close enough to ideal (5H/1m), yet I have shown via sim that a ratio of even 100:1 is close enough for a 5% error. That converts to a total series resistance of 50m Ohms.

The fact is, most high quality high power audio amplifiers have an output damping factor of about 400:1, which means the output resistance is on the order of 20m Ohms (based on 8 Ohm load). So a big audio power amp is a good ideal voltage source.

The other fact is that we can indeed short out an ideal inductor that has current flowing through it, by ideal wire or ideal voltage source. If in our example the inductor is shorted by an ideal wire right at t=3, what happens? does the inductor and the world blow up? I think we all agree that the current would remain at 2.39A. If the voltage source went to 0V rather than -4V at t=3, we know that it would act the very same way as the previous case of the ideal wire, and the current would remain at 2.39A and there would be no explosions.


Green=voltage Source
Red= Circuit Current
Purple= Voltage Source Power

Even the best some times make mistakes.

Quote post 63-Poynt
My blown universe post was a bit of a ruse. In fact it implied the opposite of what would theoretically happen, that is, "nothing".

Quote post 74-me
So you are saying that at T=0--the instant the ideal voltage is placed across the ideal inductor,nothing would happen?--no voltage would appear across the ideal inductor?.

quote post 81-Poynt
Yes, nothing will happen with the ideal inductor, i.e. it will have 4V (or whatever the voltage is at any point in time) across it and zero current through it for ever and ever.

Quote post 84-MH
Brad:
You have actually been given part of the answer, and you see that you were dead wrong.  Turn that into a learning experience.
Seems at this time,both myself and Poynt are wrong.

Quote post 106-Poynt
Unless I'm overlooking something, or don't correctly understand the question, there will be no current, and the voltage across the inductor will be whatever the voltage source is at any one time, from t=0 to the end of time.
Given that tau=infinity, there can be no change in either I or V. Indeed if R is non-zero, there will be a current and the voltage change over time.

Quote post 123-Poynt
For your test (13s of a few different voltages), the different voltages have no affect on the outcome.

So the question could have been asked with one voltage and still have the same answer, correct?
I did the simulation with 0.0000000001f (femto) Ohms, which is very very small, and ran it for 100s, far exceeding the limit of your test. The current stayed flat at 0A for the full 100s. Needless to say the voltage across the coil also remained at 4V for the entire 100s.
I think we can conclude from these results that my answer is correct.
So here a very small value of resistance was used in the sim,and an answer given by the sim.
Odd that as soon as we increase the resistance of the coil,the sim starts showing different results.
Was the sim unable to replicate the actual question?.

Quote post 56-MH
The sim will work perfectly

What happens when the sim dose not show the results MH wants to see
Quote post 127-MH
Perhaps forget about the sim and do it in your head

Quote post 328-verpies
It is impossible to connect such voltage source across a shorted ideal inductor, because in such case  this voltage source would see a load, which does not have any resistance nor reactance

And this is the part you are all missing here.
We have agreed that between T=3s and T=5s,when the voltage value is 0v,a current of 2.4 amps will continue to flow through the ideal coil and ideal voltage source circuit,and will not fall in value,due to there being no resistance in this loop. This can only mean that the loop is a dead short,or shorted loop-continual loop with no resistance.So the ideal voltage source !is! the ideal short across the ideal coil,and this inductor has no resistance,and since the current flow is steady at 2.4 amp's,it also has no reactance. At T=5s,we are now going to try and place a negative voltage across this shorted ideal coil

Quote post 7--MH
no,a voltage cannot exist across an ideal inductor that has a DC current flowing through it.
Quote post 336-Poynt
All inductors, whether ideal or real will have a voltage across them when there is current through them, regardless if the current is changing or not.
Who is correct here?.

But my example switches the voltage from +4V to -4V, right at the instant 2.39A is flowing in the coil and voltage source. What happens next is the opposite from the period between t=0 and t=3; the current ramps down from 2.39A to 0A, and the power instantly changes from -9.56W to +9.56W, and ramps back down to 0W. The energy stored in the inductor is returned to the voltage source. No energy was dissipated when the inductor was energized, and none is dissipated when it de-energizes.

Quote post 425-MH
An ideal voltage source does not "contain energy"


It would seem that there needs to be a few things ironed out,as no correct answer can be obtained from those that are trying to give it,being in disagreements with each other.

First things first
MH-a voltage cannot exist across an ideal inductor that has a DC current flowing through it

Poynt-All inductors, whether ideal or real will have a voltage across them when there is current through them, regardless if the current is changing or not

Second
MH-An ideal voltage source does not "contain energy

Poynt-TThe energy stored in the inductor is returned to the voltage source


Brad

Resonance and tuning both play a great part to the efficient running of an ICE both internally and externally.

Yes, it's easy to say those things.  But assuming that we are talking about the true scientific and engineering definition for resonance, so far the only thing that I am aware of is Helmholtz resonators for the air intake of a two-stroke engine.  For a modern four-stroke engine in a typical car, I am aware of nothing at all.

The word resonance is a ridiculously abused, misunderstood, and recklessly applied concept on the free energy forums.  In Russ' forum on the Rodin coil testing thread, someone posted this "resonance" clip called "Resonance in a bifilar coil."

https://www.youtube.com/watch?v=qtI1CPBSm-o

The clip has absolutely nothing whatsoever to do with resonance, nada.  However, presumably most of the readers of the thread are gobbling it up and believing it does.

If you can make valid points about resonance in an ICE, I would be most interested in learning about it.  But just throwing the term around like a marketing buzz word or some mechanic's shop talk will not work for me.

MileHigh

I know you can do much better than that Brad.

I put time and effort into that post, which clearly illustrates what happens. I'd be interested in your thoughts on that particular post and why you still believe the results shown are incorrect.

Even from a layman's point of view (and I'm not implying you are a layman), I would think the scope shot makes perfect sense.

For example, do you not agree that the calculated power from t=3 to t=6 ramps from +9.56W to 0W? We know there is 2.39A of current flowing, and now that the voltage has reversed, it is actually in-phase with the current, so the power goes positive, i.e. +2.39 x -(-4) = +9.56W.

Green=Voltage Source Voltage
Red=Circuit Current
Purple=Voltage Source Power

Dear MileHigh.

For some strange reason I still cannot " quote reply " it comes back with page unavailable.

I wasn't actually referring to car engines but more to the " Stationary " engine side where the fixed RPM creates a fixed frequency. By tuning the exhaust pipe correctly the expanding gasses can actually scavenge the combustion chamber reducing the effort required on the intake side.

I have attached a couple of references to exhaust tuning and I got a surprise to read that Ferrari are employing tuned extractor manifolds on their V 10 engine.

http://www.endtuning.com/exhaustsystems/

https://en.wikipedia.org/wiki/Tuned_exhaust

Cheers Grum.

Grum
Don't confuse Miles with FACTS ...his mind is already made up...

Chet, I have some advice for you:  Stop acting like a jackass.

Dear MileHigh.

For some strange reason I still cannot " quote reply " it comes back with page unavailable.

I wasn't actually referring to car engines but more to the " Stationary " engine side where the fixed RPM creates a fixed frequency. By tuning the exhaust pipe correctly the expanding gasses can actually scavenge the combustion chamber reducing the effort required on the intake side.

I have attached a couple of references to exhaust tuning and I got a surprise to read that Ferrari are employing tuned extractor manifolds on their V 10 engine.

http://www.endtuning.com/exhaustsystems/

https://en.wikipedia.org/wiki/Tuned_exhaust

Cheers Grum.

Okay I going to pull the key quote from the first link for starters.

<<<  pipes can be thought of like an Organ pipe. For each diameter and length, there is a resonant frequency, in the same way Organ pipes are different sizes and diameters to produce different notes.
Exhaust tuning uses this resonance to help evacuate the gasses from the cylinders.
This is the main point.
A finely tuned exhaust not only reduces the back pressure to minimal levels, it can actually pull the gasses out of the cylinders!
When correctly designed, the exhaust can be tuned to resonate and the pressure vibrations in the exhaust can be timed to have a low pressure wave arrive at an exhaust valve as it opens, pulling the gasses out.  >>>

I am not going to pretend that I am an expert on this stuff but let me tell you what I think.

An organ pipe is basically a big whistle.  Here is a clip explaining how a whistle or organ pipe works and how to make one:

https://www.youtube.com/watch?v=z8uwLv3s9w8

Okay for starters, exhaust pipes don't really act like whistles or organ pipes.  So the comparison being made is incredibly weak at best.

In the description they are describing an exhaust pipe that helps scavenge the cylinder of exhaust gasses.  This is done with an exhaust pipe with no chamber, just a straight pipe.  Under those circumstances you get a reflection at the open end of the pipe that travels back up the pipe to the cylinder as a negative pressure wave.  When the wave front of the negative pressure wave reaches the cylinder that will help scavenge the exhaust gasses out of the cylinder.

What you are looking at here is what I already covered with Brad, but this time it is for a negative-pressure reflected wave, and not a positive-pressure reflected wave.

That means that the exhaust pipe is not resonating at all, rather, it is acting like a time delay device to synchronize the returning negative pressure wave with the scavenging of exhaust gasses out of the cylinder.

Since it is a timing delay device, and the engine has a repetition rate for the firing and exhausting of gasses from the cylinder, there is an optimum frequency for the engine, or a near-optimal frequency range for the engine for increased performance.

Does adjusting the length of the exhaust pipe change the optimum engine RPM for the effect?  Of course it does, because you are changing the amount of time delay for the arrival of the negative pressure wave, but this is not resonance.

So, my conclusion for the first link is that they are just using non-scientific marketing/shop talk when they talk about tuning the exhaust pipe for "resonance."  There is nothing actually resonating in the pipe.  Rather, it is acting like a short sound echo chamber.

I have no issue if you refer to this as "resonance" in your vernacular when working on engine exhausts, but relative to the true scientific and engineering definition for resonance, the exhaust pipe is not acting like a resonator.  That's in contrast to a pipe organ or a whistle, where the tube is acting like a resonator and kinetic and potential energy is resonating back and forth in a standing sound wave inside the tube.

It's all about truly understanding what is happening in the exhaust pipe and not just throwing a cool-sounding word at the process.

I will now review the second link.

MileHigh

Obeewannabee
Your tune is not resonating with reality ,in addition to Many,  many other factors in ICE design  the speed of sound is most relevant ... to remove resonant tuning and replace it with some purely semantic word salad and declare it as fact and not relevant to resonance is

at the very least ignorance ..
and while we're on the topic of your ignorant semantic rants...
they are 99.9 percent semantic

.099 % substance
and .001% useful on Brads bench whilst he tunes for resonance

Oh
the aforementioned  .001% non semantic "useful" contribution on Brads bench

purely for humor as he giggles about your  useless semantic contributions on his real world bench.

If you had posted the material that smokey had posted and its relevance to NMR , NAR and LENR
 perhaps it would have been useful to an OU experimenter on his bench

Your  semantic Diatribes regarding resonance are of no use whatsoever to Brad.
they do seem to be very important to you ...

and your "Whine" glass !!