What's a Fusible Link?

[Lumpy]

I mean, I know what a fusible link does. But what's it's construction? Is it something other than a tinned copper wire of appropriate gauge? Or is it some kind of metal that somehow melts at deliberate current but otherwise carries the appropriate current without a voltage drop?


Fusible Lump

[Lumpy]

Wow. My post about fusible links just showed up in the STEERING section.

... ...


Lump

[thegreenmachine]

http://en.m.wikipedia.org/wiki/Fusible_link

Wiki on it.

Rather than regurgitate info here's the page I read


Sent from AutoGuide.com App

[Lumpy]

Aw, c'mon. Regurg it. It's a discussion forum.


Lump

[Big_kid]

It's a wire large enough to handle the rated current, but overheats and melts when overloaded.

[thegreenmachine]

It's a wire large enough to handle the rated current, but overheats and melts when overloaded.

Or what big kid said.




Sent from AutoGuide.com App

[WoodButcher]

Wow. My post about fusible links just showed up in the STEERING section.

... ...


Lump

What more do you need to know? if it burns you ain't turning so bail out...
You didn't connect your ejector seat to a fusible link,
did you???

[Lumpy]

You didn't connect your ejector seat to a fusible link,
did you???

No, but that seems like a good idea. I may need some help with the wiring.

Here's my Linc -




Here's my ejector seat -




And in case of an emergency eject, I'd like to take these with me -




Lump

[CoolCat4Christ]

Here's my Linc -

Lump

Whoa Lumpy if this doesn't take me back...

[youtube]kd85Qim_Z6A&feature=player_detailpage#t=2[/youtube]

[SilverBullet1997]

I am a little slow, but...

It's a wire large enough to handle the rated current, but overheats and melts when overloaded.

or what Big Kid and thegreenmachine said...

[RECox286]

IOW, it is a FUSE, but one that is in an inconvient spot, and definitely a PITA to change out.

Or, in simple terms, it is a Current Limiter. I don't know why they are still used, except for

that they are cheap (er) devices.

Uncle Bob

[chevymaher]

IOW, it is a FUSE, but one that is in an inconvient spot, and definitely a PITA to change out.

Or, in simple terms, it is a Current Limiter. I don't know why they are still used, except for

that they are cheap (er) devices.

Uncle Bob

Yea isn't any reason to put it in the fuse panel with the rest of them. When you can hide it inside a wiring harness and put it between the frame and the block. Then don't list on a wiring diagram where you deliberately hid it. Engineers are our best friend. They get paid to think and yet that seems to be the one thing they can't seem to do. Reality Guys, try it.

[N6KB]

Any fuse has to have resistance and a voltage drop across it when some current is flowing. If there was zero resistance and zero voltage drop, there would be zero heat produced, and it would not go open circuit when the current gets too high.

[WoodButcher]

When a fusible link burns does it become the "missing link"?

[Big_kid]

Woodbutcher & N6KB are both right.

I once got into a debate with one of the TV techs when I was working in the Monkey Ward. He was trying to convince me that scientists had achieved absolute zero resistance in a superconductor. I told him it was impossible. He explained that they had this circuit built, they induced a voltage in it, and that it had continued to ring. I asked him how they knew it was still ringing, he said they could measure it. I maintained my position of absolute zero ohms being impossible, and asked him to define voltage. The little light bulb lit up when he said "I times R", and I asked "What is I times zero"?

So, to summarize, a fusible link is exactly as CM said- a poor replacement for a real fuse, located in the most inaccessible of places, and subject to failure at the most inopportune times.

[RECox286]

Egyptoligists, at one of the Cairo digs, found a fusible link that was still functioning some 12,751 moon cycles later.

Beat that one...

Uncle Bob

[WoodButcher]

Kid,,, you must have read my response in the other thread cause I haven't said anything intelligent here!

This thread, viewtopic.php?f=27&t=51418

It is not a fuse but a short section of wire that is of lighter gauge wire to create a weak spot in the circuit. You would need to replicate the amperage that that section is meant to carry at its max before it is supposed to burn.

Poor guy in Denmark needs help and he gets a like me reading the manual?

































Maybe I should apply to the Microsoft help desk!


eh, maybe not, I don't do well in open toe pumps,,

[CoolCat4Christ]

Woodbutcher & N6KB are both right.

I once got into a debate with one of the TV techs when I was working in the Monkey Ward. He was trying to convince me that scientists had achieved absolute zero resistance in a superconductor. I told him it was impossible. He explained that they had this circuit built, they induced a voltage in it, and that it had continued to ring. I asked him how they knew it was still ringing, he said they could measure it. I maintained my position of absolute zero ohms being impossible, and asked him to define voltage. The little light bulb lit up when he said "I times R", and I asked "What is I times zero"?...................................

Big_Kid, Your TV tech co-worker wasn't to far off. Read on

In the world we live in, with the accuracies we can generate it is an observed fact the R=V/I.
Infinities need careful interpretation if they happen in the physical world.
In this form when there is no current one talks of infinite resistance ( seen also on the potentiometers sold) .
When one reverses the equation to the form I=V/R one has to be careful to see if there can be any material where R is 0. There are no such every day materials because they are composed by atoms tied together with electromagnetic forces which will always display some resistance to change of status at normal temperatures.
But there exist special materials under special conditions, superconducting materials and superconductivity, which take advantage of the quantum mechanical behavior of certain metals, and there one achieves practically zero resistance and very high currents indeed, according to the voltage applied.
The simplest method to measure the electrical resistance of a sample of some material is to place it in an electrical circuit in series with a current source I and measure the resulting voltage V across the sample. The resistance of the sample is given by Ohm's law as R = V/I. If the voltage is zero, this means that the resistance is zero.

Superconductors are also able to maintain a current with no applied voltage whatsoever, a property exploited in superconducting electromagnets such as those found in MRI machines. Experiments have demonstrated that currents in superconducting coils can persist for years without any measurable degradation. Experimental evidence points to a current lifetime of at least 100,000 years. Theoretical estimates for the lifetime of a persistent current can exceed the estimated lifetime of the universe, depending on the wire geometry and the temperature.
The current in the superconductors is not found by this simple formula, but theories have been developed and methods of measuring it use the magnetic fields generated.
The LHC uses high power superconducting magnets to achieve the high magnetic fields it needs. The problem is technological, keeping the superconductors cooled and the high power needed under control.

The amperage is current flowing through the superconductor. All superconductor have a critical magnetic field they can counter before the superconducting phase breaks. This critical magnetic field also implies a critical electrical current, because all current will generate an associated trasverse magnetic field.
What happens to the omhic law in a superconductor is that a non-zero (but below critical) current can be sustained indefinitely even in zero voltage, so the ohmic law relationship becomes an indefinite 0/0 expression, which can be understood as a breakdown of the dependence between the quantities

This is what my expression was after seeing this because I have absolutely no clue what I just read. But it makes for interesting reading:

mr fox kylie.jpg (32.94 KiB) Viewed 2885 times

[CoolCat4Christ]

eh, maybe not, I don't do well in open toe pumps,,

[chevymaher]

Okay pratically zero resistance. That is resistance right.

No resistance when zero voltage is applied. I think that applies to a resistor to. It has no resistance untill voltage is applied.

It will last longer than the universe. Now ya got me going.

The world is flat, Nuclear energy is clean and safe, Computers are more accurate and easier.

It is all theory untill it is used and we see if it pans out. If these clowns were right everytime they said this stuff. Technology would be done progressing. Because we would already have the perfect world and nothing new would be needed.

They proved perpetual energy using all these 10 dollar words and formulas a long time ago. Talkin over us poor hillbillies heads like we aint got a brain. Then why have they already lost enough radiation from nuclear power plants to kill life on earth. It was developed after that. Perpetual energy sure seems safer.

Well let me tell you what. You don't got to be a weather man to see which way the wind blows.

There will be insurmountable problems pop up these rocket scientist didn't see coming. Because reality is unforgiving. It don't care about the dream world in a formula.

They have had Super-conductors for a long long time. Ever wonder if they so great why they just experiment with them and never used them.

Oh there goes that wind again.

hillbilly.jpg (8.83 KiB) Viewed 2867 times