0 ohm load possible?

[helotaxi 5,000+ posts]

You COULD apply a voltage to a load of 0 ohms. The resultant currnet would theoretically be infinite. This would be the result of the divide by zero problem earlier. Since both absolutely zero ohms and infinite current are impossible...

 

[helotaxi 5,000+ posts]

movement can heat up the cone, and suspension. Certain types of foam rubber surrounds lose tension from the heat when moving, this changes driver characteristics.

The suspension heating isn't going to have a huge effect on the impedance of the driver though. At least not in the near term. If the flexing of the surround is causing even measurable heating the design flat sucks. If it's causing a significant shift in the T/S parameters, the design really sucks.

 

[Ed Lester 10+ year member]

The suspension heating isn't going to have a huge effect on the impedance of the driver though. At least not in the near term. If the flexing of the surround is causing even measurable heating the design flat sucks. If it's causing a significant shift in the T/S parameters, the design really sucks.

I agree with that. But there are alot of sucky drivers out there.

Mostly older subs using older materials. Paper cones also heat up more than aluminum and carbon fiber.

We actually got readings of up to 150 deg F during high power burps on the surround of a DD 99Z.

Of course it dropped back to room temp within 2 minutes after play.

 

[Haunz 10+ year member]

O.K. lets try a simple Ohm's Law equation using 0 ohms.
Lets find the current of a circuit which has 12v and 0 ohms of resistance.

Now Current equals voltage divided by resistance.

12v/0 ohms = ?????

alright, lets try to find wattage with that number.

we can use volts squared timer resitance.

12 x 12 x 0 = 0.

So I guess we have 0 wattage too.

Or we can use 100A as a figure and try and find voltage with 0 ohms.

We just have to multiply current times resistance. so we have.

100 x 0 = 0 and that means we have 0 volts.

Yes Ohm's law is working perfect with 0 ohm superconductors.

Thank you for clearing that up.

Dude, you keep posting like you know what you are talking about //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

In a superconductor current flow is only limited by:

1. the speed of light

2. the conductors critical magnetic field

I had to look at your link to 'the fundamentals of superconductors' for all of two seconds before I saw the sentance: "Superconductors have the ability to conduct electricity without the loss of energy"

ie. ZERO OHMS

What school taught you about superconductors again ? //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[Ed Lester 10+ year member]

Dude, you keep posting like you know what you are talking about //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif
In a superconductor current flow is only limited by:

1. the speed of light

2. the conductors critical magnetic field

I had to look at your link to 'the fundamentals of superconductors' for all of two seconds before I saw the sentance: "Superconductors have the ability to conduct electricity without the loss of energy"

ie. ZERO OHMS

What school taught you about superconductors again ? //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

The current is also limited by the material that is carrying it. Every material will have its critical current limit. when that point is reached, it ceases to become a superconductor.

I may be forgetting some info but you are too.

If there is a limit on current, does that not mean that infinite current and thus 0 ohms is impossible.

 

[Kyle_Keating 10+ year member]

so who here actually has an engineering degree?

because otherwise i can wiki with the best of them.

 

[Ed Lester 10+ year member]

I do

 

[qkassidyw 10+ year member]

Me too...and I don't think the statement of conducting current without a loss of energy is correct by your analysis. I don't think it is saying what you think it is...is what I'm trying to say.

(Nobody every said engineers were good at English!)

 

[Ed Lester 10+ year member]

Me too...and I don't think the statement of conducting current without a loss of energy is correct by your analysis. I don't think it is saying what you think it is...is what I'm trying to say.
(Nobody every said engineers were good at English!)

I always failed English but got straight A's in Math.

Do you believe there is a limit on current, or do you believe current can be infinite and that it can be driven with 0 voltage?

 

[ultimate157 5,000+ posts]

How can you have infinite current? Jesus I can't believe people are still arguing its possible to have a 0 ohm load IN REAL LIFE. Obviously you "theoretically" could...just like "theoretically" you could have 100% efficiency..."theoretically" you could reach absolute zero...problem is in real life, its not possible. So in reality, it doesn't even exist, and never will exist, because its not possible.

Have you taken Calculus? Do you know about limits? Doesn't matter that division by 0 is impossible... Take the limit of the equation as it approaches zero and you get your answer.

Same thing with "You can't reach absolute zero" blah blah blah. You can get to .000000000000000000000000000000000000000000001 of a degree above absolute zero, but according to you that's not close enough to be absolute zero.

You keep saying theoretically to prove your point, but in real life you can get so extremely close to the theoretical limit that for all intents and purposes, it is assumed to be that limit.

 

[Rashaddd 5,000+ posts]

Have you taken Calculus? Do you know about limits? Doesn't matter that division by 0 is impossible... Take the limit of the equation as it approaches zero and you get your answer.
Same thing with "You can't reach absolute zero" blah blah blah. You can get to .000000000000000000000000000000000000000000001 of a degree above absolute zero, but according to you that's not close enough to be absolute zero.

You keep saying theoretically to prove your point, but in real life you can get so extremely close to the theoretical limit that for all intents and purposes, it is assumed to be that limit.

Yes I've taken calculus, yes I know all about limits. But the original question is asking about a ZERO ohm load strictly. I realize you could say, yes for useful purposes you could get very very close...but I think even the guy who asked the question realized that...hell just keep adding more shit in series or directly short it out and theoretically you get close...but the question is can you actually have ZERO some how, which you can't. The quesiton is ZERO as a concept, and the answer is no. Its like asking if something can have zero mass...yea, you can get ridiculously close...to the point that it doesn't even behave as if it has mass anymore...but you can't have zero, and actually achieving the 'zero' is what is important...I think we can all agree its pretty obvious you can keep getting smaller and smaller amounts, but as a concept, you can't have zero.

Its like saying we can count to infinity...well..yea obviously we can just keep getting higher until the added digits no longer affects our answer in any noticeable way...but as a concept..you can't count to infinity...

if the question is really 'can we just keep lowering impedence until its immeasurably small'...come on...how hard is it to figure that one out...thats like asking if I can keep cutting something in half until its no longer visible to the ***** eye...obviously thats possible...but is it possible for me to cut it in half till there's nothing left? no.

 

[Haunz 10+ year member]

The current is also limited by the material that is carrying it. Every material will have its critical current limit. when that point is reached, it ceases to become a superconductor.
I may be forgetting some info but you are too.

If there is a limit on current, does that not mean that infinite current and thus 0 ohms is impossible.

Thanks for the observation, sherlock...

before a critical magnetic limit is reached a superconductor has:

ZERO RESISTANCE

I never said anything about 'infinate current' //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

 

[Haunz 10+ year member]

so who here actually has an engineering degree?
because otherwise i can wiki with the best of them.

I've got better... chemistry with a minor in physics... FTW

 

[giants25al 10+ year member]

it doesn't take abosolute 0 K for the majority of conductors to become non resistive. (-273 C) not that yall didn't know that allready. Actually most metals that you would assume that would be used in speakers reach there "inferred absolute zero around -240ish C" such as copper and aluminum. There are also alot of materials that reach there "inferred absolute zero" much much lower than 0 K. Such as Nichrome, Constantan, Mercury, and Manganin. Not that my 2 cents is worth anything //content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

 

[giants25al 10+ year member]

I'm out of my league with you guys though. small circuits not my thing, I work on powerlines where all I need to know is not get in between phases and dont be a path from phase to ground. I like all my limbs and skin //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif