The fuse thing is a funny one, as I've encountered otherwise intelligent people, but non-technical ones. who used "I could hear the fuse" as his/her example of the height of audiophile nonsense. When I corrected them and explained how fuses work, and the almost-inevitable nonlinearity associated with the mechanism even well below the threshold of discontinuity, they became a little less derisive.
I have noticed a change in the construction lately of some cheapo time-delay aka slow-blow parts. Instead of a construction with the element wrapped around a core, there are little blobs at the ends visible on the way to termination at the end caps. Does anyone know what's happening there?
This came about because the local audiophile gave me a tube power amp that had stopped working, and he didn't want to bother with determining why. It had a blown mains fuse, and of course that's usually a sign of some other difficulty. But as far as I could tell it was just undersized and had failed due to work hardening from power cycling, almost certainly (mostly) the cold heaters surge. There was even a spare in the mains input IEC connector assembly. But since I had no more of them I brought the power up with a variable transformer after that. When I got round to acquiring some more I noticed the new construction.
I have noticed a change in the construction lately of some cheapo time-delay aka slow-blow parts. Instead of a construction with the element wrapped around a core, there are little blobs at the ends visible on the way to termination at the end caps. Does anyone know what's happening there?
This came about because the local audiophile gave me a tube power amp that had stopped working, and he didn't want to bother with determining why. It had a blown mains fuse, and of course that's usually a sign of some other difficulty. But as far as I could tell it was just undersized and had failed due to work hardening from power cycling, almost certainly (mostly) the cold heaters surge. There was even a spare in the mains input IEC connector assembly. But since I had no more of them I brought the power up with a variable transformer after that. When I got round to acquiring some more I noticed the new construction.
Very carefully.
Maybe they used E beam welding with the modulation envelope set to "ridiculous"?
jn
Christophe,
Are there fuses made of this material? Constantan or Manganin. Is it a commercially available product or is this something you would only see in some satellite application or such. I would imagine that they wouldn't use a fuse in a satellite as who is going to change the blown fuse! But even in a relay or circuit breaker I would think that it is still a non-linear electrical device as regards to rising resistance with temperature.
Are there fuses made of this material? Constantan or Manganin. Is it a commercially available product or is this something you would only see in some satellite application or such. I would imagine that they wouldn't use a fuse in a satellite as who is going to change the blown fuse! But even in a relay or circuit breaker I would think that it is still a non-linear electrical device as regards to rising resistance with temperature.
J.C.
The cheaper fuses use the two blobs, the premium fuses still are the same. Both seem to work.
Scott,
To get that voltage seems to indicate there is no current. So just think Leyden jar.
Anyone have any idea what the voltage drop is across a working fuse?
Dick,
I was hoping you would show how the third rail to rail capacitor works on spikes. The use of ribbon cable is tough when you get to connectors. Being able to clean things up at the DC point of entry makes physical layout easier. (I use a 555 driving a "Logic" FET to exercise my rails.)
Anybody ever measure the voltage across a chassis from the magnetic fields inside?
SY
Did you take a peak at the Linear Audio article on regulators and the measurement of them?
Scott
The 7905 family of regulators I believe first appeared in the 70's. Is anyone still using those older processes to make current parts?
The cheaper fuses use the two blobs, the premium fuses still are the same. Both seem to work.
Scott,
To get that voltage seems to indicate there is no current. So just think Leyden jar.
Anyone have any idea what the voltage drop is across a working fuse?
Dick,
I was hoping you would show how the third rail to rail capacitor works on spikes. The use of ribbon cable is tough when you get to connectors. Being able to clean things up at the DC point of entry makes physical layout easier. (I use a 555 driving a "Logic" FET to exercise my rails.)
Anybody ever measure the voltage across a chassis from the magnetic fields inside?
SY
Did you take a peak at the Linear Audio article on regulators and the measurement of them?
Scott
The 7905 family of regulators I believe first appeared in the 70's. Is anyone still using those older processes to make current parts?
Of course- not just a peek, a very close reading. Excellent article, exactly the way that real audio ought to be done.
If you do, you'll notice that I suggested a key element of the test setup to Jack.
I dont know why analog/audiophiles take such things so hard... unless maybe it reflects poorly on them/their industry? Look at sneakers for hundreds of dollars. Diets. Congress. Every industry has its goofy side. Its the American way to let 'free enterprise' run wild. Free to make mayhem, too.
You can laugh about it or cry about it. Just laugh it off.
But speaker fuses DO make significant thd and thus were put inside the nfb loop to minimise the thd. Now, even that has been eliminated and changed to relay contacts or something else. In pwr supply bypass them with a small value c or use circuit breakers. This is typical of the scammers in all industries.... find a legit issue and turn it into an excessive extreamist do-dad/gizmo. Or just gold plate it. Its the American way. Buyer beware.
Thx-RNMarsh
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Exactly so. That's why it's the responsibility of ethical engineers and scientists to point out that these claims are just scams rather than reflexively defending them.
If you need any help with changing the car tire, give me a howler.
(or try complete induction)
Or just use one of these
Amazon.com: THE SPY SPOT - 7.8 Million Volt Rechargeable Stun Gun w/Built-in LED Flashlight & Holster: Sports & Outdoors
Let's see, 7.8M volts at a "safe" 2mA limit (15,600 W) WoW!
. Unfortunately the gap pictured holds off 40-60kV max so these claims are clearly false, sound familiar.This stuff is old BTW, I had a neighbor that threatened her kids with a cattle prod 50yr. ago. Nice big stick with 6 D cells.
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When someone comes up with something like the plastic pizza protector to keep the cheese off the inside of the top of the box we all say why didn't I think of that! That is a product that serves a real need as simple as it may seem. But when someone comes up with magnets to go in your shoes or on your wrist to solve some medical condition we have to look long and hard at any science if any and determine if it is just snake oil. From what Scott and others have said here it looks that there is some truth to how some cabling may have a real electrical component to the design such as the way it is braided in construction. But when those cables start cost 100's to 1000's of dollars a foot then it becomes a cost benefit ratio that seem completely out of proportion to any real gain in performance. At some of those costs I would learn how to braid a couple of wires real fast if I wanted the small improvement that they may have. Does it really matter if someone uses magnesium instead of die cast aluminum in a speaker frame, probably not but it could be used as a marketing tool to distinguish the product. As was just said: buyer beware.
Or read the sales brochure : TESLA Series Technologies | Synergistic Research
(doesn't say if frequent flyer miles are included)
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