I was a skeptic but this experiment proves so. It seems legit, that is unless the data has been massaged. Anybody can detect anything here?
http://www.hifi-tuning.com/pdf/wlfr.eng.pdf
http://www.hifi-tuning.com/pdf/wlfr.eng.pdf
One has to wonder how a piece of wire has different directionality. Assuming it did, then I suppose you would test each fuse individually before installation to determine which way saves you 2/100 of a milliohm?
The testing assumes all fuses were making contact with the test setup at exactly the same points on each end.
I had a junior tech once working on an old Crown 300. Had five fuse holders across the front behind the panel. One main fuse, and V+ and V- fuses for each channel. One channel had no V rail on one side. Jump to the end of story. One fuse was not working. Replaced it and amp worked. But fuse looked OK and tested OK with a meter, and sure enough it worked in one of the other holders. All the fuses worked in all the holders except the one. The one fuse worked in all holders except the funny one. And all the other fuses worked in ALL the holders. And it was consistent, I could do it over and over. I showed the junior tech this, and he assured me it was just impossible for this condition to exist. And yet there it is.
But it illustrates that fuses are not as precision made as we might assume, so clearly something about the nuance of shape of this one fuse and the nuance of shape within that one holder worked so the fuse would not make contact in that holder. Yes, inverting the fuse made it work too.
So as soon as you mention directional measurements of fuses, that experience leaps to mind.
The testing assumes all fuses were making contact with the test setup at exactly the same points on each end.
I had a junior tech once working on an old Crown 300. Had five fuse holders across the front behind the panel. One main fuse, and V+ and V- fuses for each channel. One channel had no V rail on one side. Jump to the end of story. One fuse was not working. Replaced it and amp worked. But fuse looked OK and tested OK with a meter, and sure enough it worked in one of the other holders. All the fuses worked in all the holders except the one. The one fuse worked in all holders except the funny one. And all the other fuses worked in ALL the holders. And it was consistent, I could do it over and over. I showed the junior tech this, and he assured me it was just impossible for this condition to exist. And yet there it is.
But it illustrates that fuses are not as precision made as we might assume, so clearly something about the nuance of shape of this one fuse and the nuance of shape within that one holder worked so the fuse would not make contact in that holder. Yes, inverting the fuse made it work too.
So as soon as you mention directional measurements of fuses, that experience leaps to mind.
More holes than a sieve.
What is this waste of time and good data supposed to "prove"?
Because it shoots itself in the foot every inch of the path.
Just two of dozens, and even that is giving it more attention than it deserves:
1) it claims to suppossedly show "directionality" which would be proven by consistent different resistance values, measured both ways.
Point is, it consistently shows , dozens of times, that resistance is the same both ways.
But ... but ... but ... numbers are different!!!!
Well, might be different in Accounting, where 1 cent difference is significant, and, say, 44,47 MILLION Dollars are very different from 44,57 MILLION by a good 10.000 Dollars, so you MUST chase the thief who stole them.
But this is the Physics World, where those numbers indicate *measurements* which by definition have some measurement error and some tolerance.
So in this case, 44,47 milliohms and 44,57 milliohms are exactly the same.
The so called difference is smaller than measurement error.
If you do not understand and accept that fundamental fact, you can not argue anything involving Physics.
2) "paper" writer has no clue about Math ... and readers who do not challenge that fraud, a publicity ad disguised as a "Scientific Test" do not show much of it either.
I mean readers who can stomach it in full, of course.
He claims (cut and paste):
His claim misses big time, as in 2200% error.
´Nuff said.
EDIT: what Enzo said, of course.
The Voice of Experience.
What is this waste of time and good data supposed to "prove"?
Because it shoots itself in the foot every inch of the path.
Just two of dozens, and even that is giving it more attention than it deserves:
1) it claims to suppossedly show "directionality" which would be proven by consistent different resistance values, measured both ways.
Point is, it consistently shows , dozens of times, that resistance is the same both ways.
But ... but ... but ... numbers are different!!!!
Well, might be different in Accounting, where 1 cent difference is significant, and, say, 44,47 MILLION Dollars are very different from 44,57 MILLION by a good 10.000 Dollars, so you MUST chase the thief who stole them.
But this is the Physics World, where those numbers indicate *measurements* which by definition have some measurement error and some tolerance.
So in this case, 44,47 milliohms and 44,57 milliohms are exactly the same.
The so called difference is smaller than measurement error.
If you do not understand and accept that fundamental fact, you can not argue anything involving Physics.
2) "paper" writer has no clue about Math ... and readers who do not challenge that fraud, a publicity ad disguised as a "Scientific Test" do not show much of it either.
I mean readers who can stomach it in full, of course.
He claims (cut and paste):
Actual difference between 44,57 milliohms and 44,57 is 0,01 milliohm so 0,225% .
His claim misses big time, as in 2200% error.
´Nuff said.
EDIT: what Enzo said, of course.
The Voice of Experience.
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From this report:
...A vector Impedance analyzer is a measurement unit...
But what is it, really?
What brand, what model, what specs?
What is the actual measurement setup, the equipment?
What/where is the peer acknowledging?
Who are involved: GECOM Technologies GmbH. All right.
Anything published concerning 'fuses'? "No results."
I'd say send them a mail requesting a hard copy of the report.
...A vector Impedance analyzer is a measurement unit...
But what is it, really?
What brand, what model, what specs?
What is the actual measurement setup, the equipment?
What/where is the peer acknowledging?
Who are involved: GECOM Technologies GmbH. All right.
Anything published concerning 'fuses'? "No results."
I'd say send them a mail requesting a hard copy of the report.
I can detect ********. In fact my ******** detector is going off the scale.
Oops, forgot i cannot say ******** in polite company.
Enzo... I've had weird fuse behaviour to. Intermittent where the fuse wire bonded or in this case just touched the end cap. It was top end Hitachi cassette deck belonging to one of our best techs and it always went dead when he wanted to record something 
It was ongoing for a couple of years...
Can a fuse be directional?
I can think of conditions where it might but I wouldn't like to say by how much. Imagine a thin wire cartridge fuse... and the fuse physical construction is not symmetrical in all its physical properties. That fuse will have thermal distortions that now relate to the characteristic of the holder and its supports/PCB copper etc and because the fuse construction is non symmetric the distortion will vary according to direction.
Answers on a postcard
Next!
It was ongoing for a couple of years...Can a fuse be directional?
I can think of conditions where it might but I wouldn't like to say by how much. Imagine a thin wire cartridge fuse... and the fuse physical construction is not symmetrical in all its physical properties. That fuse will have thermal distortions that now relate to the characteristic of the holder and its supports/PCB copper etc and because the fuse construction is non symmetric the distortion will vary according to direction.
Answers on a postcard
Next!
I can find the differences in two measurements of fuses to be quite believable. Not really surprised. If any of you have ever tried to measure the resistance of a fuse the first issue is not surprisingly that fuses resistance varies with temperature. A very important principle in how fuses blow open to prevent over current.
So if you pick up a fuse of the small cylindrical type as used in the report, I would expect the value to change just from touching it.
Perhaps that explains why virtually all of the second measurements are higher than the first. For the exceptions I would wonder about the initial handling time and possibly an interruption in testing times.
So if you pick up a fuse of the small cylindrical type as used in the report, I would expect the value to change just from touching it.
Perhaps that explains why virtually all of the second measurements are higher than the first. For the exceptions I would wonder about the initial handling time and possibly an interruption in testing times.
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- I have to say that we measure dissipated power in Watts, but not in Volt-Amperes (as it is stated in that document).
"VA" is for alternative current.
Never tested solid core wire that would not sound directional. Against all reason and expectation.
And although this may be a mystery, measuring resistance is not and it comes as a shock that a manufacturer would publish such obviously falsified data. To what end? Just to illustrate their cluelessness in measurements?
for ac current the solution is obviously just like using back to back electrolytic capacitors. Just put two fuses in series, with opposite directions.
This also should help reduce any coloration caused by fuse directionality. Of course one must carefully match the fuses' strengths of directionality for cancellation to be optimal.
It can also be derived from the practice of putting smaller, high quality capacitors in parallel with larger capacitors, that one should put high quality lower current fuses in parallel with higher current ones.
This also should help reduce any coloration caused by fuse directionality. Of course one must carefully match the fuses' strengths of directionality for cancellation to be optimal.
It can also be derived from the practice of putting smaller, high quality capacitors in parallel with larger capacitors, that one should put high quality lower current fuses in parallel with higher current ones.
They also mention slow-blow fuses. I have to wonder exactly when a slow-blow fuse would be used in a situation where any "directionality" would have any effect at all. You shouldn't use slow-blow fuses for speaker protection in an amp with speaker fuses. If it's the mains fuse (likely), then the resistance of the fuse is swamped by the DC resistance of the transformer windings.
Furthermore, as has been pointed out, this "article" reeks of marketing BS. It claims the best fuses are made by the same company that created this lovely piece of creative writing. That alone should raise an eyebrow.
Furthermore, as has been pointed out, this "article" reeks of marketing BS. It claims the best fuses are made by the same company that created this lovely piece of creative writing. That alone should raise an eyebrow.
Oh the old "does a resistor measure the same regardless of polarity" joke....
I once had an apprentice ask me a resistor was "one way" and measured differently when inverted.
It was a running joke for a while.
Not unless it's a lossy diode. And then, well it isnt a resistor any more.
I have plenty of fuses, 20mm, 25mm, 38mm, HRC, HV (24kV 1A), cartridge fuses, tabbed fuses.
The only ones that work best in one orientation...are the Indicator fuses.
If you know what these are, then you know why
I once had an apprentice ask me a resistor was "one way" and measured differently when inverted.
It was a running joke for a while.
Not unless it's a lossy diode. And then, well it isnt a resistor any more.
I have plenty of fuses, 20mm, 25mm, 38mm, HRC, HV (24kV 1A), cartridge fuses, tabbed fuses.
The only ones that work best in one orientation...are the Indicator fuses.
If you know what these are, then you know why
You're in the wrong place. Please try Audio Asylum -- Audio Reviews, Audiophile Forums and Stereo Reviews
Actually I can think of a reason why there could be "directionality." I've read but not experienced, that corrosion of the contacts can have a diode effect, although this was given as a possible cause of distortion with audio connectors.
If I'd been writing for the Asylum, this would have been more appropriate: "Unless the fuse will be used with pure DC current, don't worry. AC constantly reverses direction, as we all know. Therefore, it is clear that, even if the resistance (impedance with AC) is not the same in both directions, the errors will cancel out, resulting in a smoothed average waveform on the downstream side of the fuse."
Actually I can think of a reason why there could be "directionality." I've read but not experienced, that corrosion of the contacts can have a diode effect, although this was given as a possible cause of distortion with audio connectors.
If I'd been writing for the Asylum, this would have been more appropriate: "Unless the fuse will be used with pure DC current, don't worry. AC constantly reverses direction, as we all know. Therefore, it is clear that, even if the resistance (impedance with AC) is not the same in both directions, the errors will cancel out, resulting in a smoothed average waveform on the downstream side of the fuse."
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