Silicone USB wire flexible as a thin rope

[Someone]

That the internal wires are enameled is not important. What is important, and you didn’t quote, is the “118pcs” part, which likely means 118 strands, which is very high (high strand count is good).

I have a problem to believe that there is 118 strands in a cable of Ø3.5mm OD because 118/4=29.5 and 118x4=472

>50 strands in AWG 20 or 22 is entirely believable, 118 possible since there are numerous off the shelf wires in that scale (though have not seen exactly 118).

[Ranayna]

Would that not more likely be 118 strands in total accross all conductors? With proportionally more for V+ and V-.
Or would that then not be enough for good flexibility?

[tooki]

I have a problem to believe that there is 118 strands in a cable of Ø3.5mm OD because 118/4=29.5 and 118x4=472

The number of strands is likely not the same for all 4 conductors. Chances are the ground and 5V wires are much thicker than the data lines.

I have 0.25mm2 PVC wire (which is softer than most silicone) that has 128 strands. Outer diameter 1.4mm. And that is not a special thin insulation. So even if it were 4x118 (which I doubt, given the 2.5A rating), it could still fit in the 3.5mm. Not scary at all, quite common in test lead wire.

PS : an enameled wire don't require any polymer insulation 

The problem is that stranded enameled wire is much harder to work with (e.g. can’t crimp it). So we avoid it wherever possible. So we really just see that in litz wire and earbud cable.

P.S. The enamel used on enameled wires are polymers.

[Coordonnée_chromatique]

Thanks for your answers,
AWG20 gives a Ø0.519mm², 0.519/118=0,0043983050847458
4 square microns for each strand for 4$, it is a recent techological exploit ?
i've measured the conducors with a caliper, they are all the same diameter (AWG20), i'm perhaps wrong but the more there is strands the less is the current rating and a such tiniy wire is very easy to overheat... 

i've choosing to make a test with an antique computer cable (because no one have any round proposal) with the idea to use the sheild for the GND and two conductors for the VCC and i don't know if it is a good or a bad idea but the cable is thin an flexible.

PS : one hair is 70 to 100 microns of Ø

[tooki]

The current capacity is determined by cross sectional area. Whether it is a single solid wire or divided into hundreds of strands doesn’t change that.

You have that cable, so you could cut off a piece and count the strands in one of the conductors within.

Extremely thin wire is nothing new in the slightest. No new “technical exploits” needed.

[Coordonnée_chromatique]

The current capacity is determined by cross sectional area. Whether it is a single solid wire or divided into hundreds of strands doesn’t change that.

You have that cable, so you could cut off a piece and count the strands in one of the conductors within.

Extremely thin wire is nothing new in the slightest. No new “technical exploits” needed.

I've wrote that because of the prohibitive price of the multi strand silicone wire for the RC cars in the 90's, we were a small group of electric car evangelists and a that time the size of the market and the technology were dictated a very expensive price... i'm not so old.

Here is a table that decrease the current load ratings with the number of strands, where is the bias please ? 
https://www.engineeringtoolbox.com/wire-gauges-d_419.html

[tooki]

The current capacity is determined by cross sectional area. Whether it is a single solid wire or divided into hundreds of strands doesn’t change that.

You have that cable, so you could cut off a piece and count the strands in one of the conductors within.

Extremely thin wire is nothing new in the slightest. No new “technical exploits” needed.

I've wrote that because of the prohibitive price of the multi strand silicone wire for the RC cars in the 90's, we were a small group of electric car evangelists and a that time the size of the market and the technology were dictated a very expensive price... i'm not so old.

1. I can’t speak to the pricing back then, but high-strand-count silicone wire still costs a lot more than basic PVC stranded. It’s a lot more work to make high-strand-count wire, and silicone costs extra too. So what?
2. Your original wording made it sound like you thought such cable could not be made. You didn’t say “it’s too expensive.”

Here is a table that decrease the current load ratings with the number of strands, where is the bias please ? 
https://www.engineeringtoolbox.com/wire-gauges-d_419.html

Nothing on that page supports your claim. Nowhere on it is there a table showing that current capacity decreases as strand count increases. It just shows that thinner wire (higher AWG number) handles less current, which we all understand and was not under dispute.

By definition, the AWG of stranded wire is the total cross-sectional area. Consequently, the resistance of solid and stranded wire of the same AWG is the same, because by definition they have the same cross-section. The current capacity (“ampacity”) rating depends on many factors, including insulation material and thickness, tolerable temperature increase, tolerable voltage drop, where it is installed, and how many wires are bundled together.

[ebastler]

By definition, the AWG of stranded wire is the total cross-sectional area. Consequently, the resistance of solid and stranded wire of the same AWG is the same, because by definition they have the same cross-section.

And if we assume hexagonal packing of circular conductors, the relative area of the cross section which is filled by copper (rather than air gaps) does not depend on how many strands one uses. To a good approximation, a bundle of 7 thick copper strands will have the have the same effective copper cross section as a bundle of 37 or 1000 correspondingly thinner strands with the same bundle diameter. The packing density remains at ~90%.

[tooki]

Indeed! Although high-strand-count frequently uses rope stranding (i.e. the overall wire consists of several bunches of strands, each of which has regular concentric stranding within). That does add extra air gaps, increasing overall conductor diameter slightly.

[Coordonnée_chromatique]

The current capacity is determined by cross sectional area. Whether it is a single solid wire or divided into hundreds of strands doesn’t change that.

You have that cable, so you could cut off a piece and count the strands in one of the conductors within.

Extremely thin wire is nothing new in the slightest. No new “technical exploits” needed.

I've wrote that because of the prohibitive price of the multi strand silicone wire for the RC cars in the 90's, we were a small group of electric car evangelists and a that time the size of the market and the technology were dictated a very expensive price... i'm not so old.

1. I can’t speak to the pricing back then, but high-strand-count silicone wire still costs a lot more than basic PVC stranded. It’s a lot more work to make high-strand-count wire, and silicone costs extra too. So what?
2. Your original wording made it sound like you thought such cable could not be made. You didn’t say “it’s too expensive.”

Here is a table that decrease the current load ratings with the number of strands, where is the bias please ? 
https://www.engineeringtoolbox.com/wire-gauges-d_419.html

Nothing on that page supports your claim. Nowhere on it is there a table showing that current capacity decreases as strand count increases. It just shows that thinner wire (higher AWG number) handles less current, which we all understand and was not under dispute.

By definition, the AWG of stranded wire is the total cross-sectional area. Consequently, the resistance of solid and stranded wire of the same AWG is the same, because by definition they have the same cross-section. The current capacity (“ampacity”) rating depends on many factors, including insulation material and thickness, tolerable temperature increase, tolerable voltage drop, where it is installed, and how many wires are bundled together.

1_it was partially the reason of my reaction 
2_You are right, it is the second part of my reason.

I've perhaps misinterpreted the table, the cross-sectional area is constant (in the same line) and the current load ratings varies with the number of strands... in the same line 

[ebastler]

I've perhaps misinterpreted the table, the cross-sectional area is constant (in the same row) and the current load ratings varies with the number of strands... in the same line 

That table claims very steep derating with higher strand counts. I'm not sure I trust those values.

Compare with the table by Lapp, an actual manufacturer of cables, below. ("Correction factors for more conductors", table in the bottom right.) The gradual derating they show is more plausible and will be due to a combination of the additional rope stranding mentioned by tooki, and probably some additional air gaps in the finer bundles (i.e. the "dense hexagonal packing" assumption not holding up strictly).

https://t3.lappcdn.com/fileadmin/DAM/Miltronic_Denmark/4_servicecenter/T13.pdf

[tooki]

I've perhaps misinterpreted the table, the cross-sectional area is constant (in the same line) and the current load ratings varies with the number of strands... in the same line 

It does not say “number of strands”. It says number of cores, which means number of conductors (wires) in a cable. (Cable and wire are not synonyms in electronics.) It doesn’t say anything about the construction of each conductor; that can be a single solid wire, or it can be stranded wire of any stranding that adds up to the same cross section.

Before the table, the text says: “The table below indicates the current ratings of PVC-insulated single and multicore wiring cables.”
The footnote (1) says “Current ratings for up to 1000 V , PVC-insulated single and multicore wiring cables, ambient temperature up to 30°C”

So the example line you show, for 24AWG, means the current per conductor in a single 24AWG wire (3.5A) and for cables with n number of 24AWG conductors (wires) within the cable. For example, if you have a 4-conductor cable, and each conductor is 24AWG, then it gets derated to 1.6A.

Why the derating? Because the extra layer of insulation (the cable jacket) reduces cooling, and the heat produced by each conductor affects the others.

[tooki]

I've perhaps misinterpreted the table, the cross-sectional area is constant (in the same row) and the current load ratings varies with the number of strands... in the same line 

That table claims very steep derating with higher strand counts. I'm not sure I trust those values.

Compare with the table by Lapp, an actual manufacturer of cables, below. ("Correction factors for more conductors", table in the bottom right.) The gradual derating they show is more plausible and will be due to a combination of the additional rope stranding mentioned by tooki, and probably some additional air gaps in the finer bundles (i.e. the "dense hexagonal packing" assumption not holding up strictly).

https://t3.lappcdn.com/fileadmin/DAM/Miltronic_Denmark/4_servicecenter/T13.pdf

You are making the exact same mistake of confusing “strand” and “conductor”. Lapp isn’t saying anything whatsoever about the stranding, either.

Since I know the German terminology, “conductor” = “Leiter” (or “Ader”) and “stranding” = “Leiteraufbau”.

The two ampacity tables do not differ much, actually. The values in the 75°C column of the Lapp table match the one from engineeringtoolbox (which it only gives as “typical” anyway), and the derating factors for more conductors are fairly similar if you do the numbers.

[Coordonnée_chromatique]

I havent read the text before the table, it seems to be the common internet generation disease   
Each core (âme) is composed of many stands (brins), so if you have 3 cores of 24AWG in the same wire (fil) the current is derated from 3.5 to 2A.

Should you say if the current rating of my 0.035mm² Mogami 3316 will suffice for a subminature camera module ?

[ebastler]

You are making the exact same mistake of confusing “strand” and “conductor”. Lapp isn’t saying anything whatsoever about the stranding, either.

Since I know the German terminology, “conductor” = “Leiter” (or “Ader”) and “stranding” = “Leiteraufbau”.

Guess you are right, that makes sense. The term I find really confusing is "core" though. I was convinced it is the same as "strand", but apparently that's not so.

[tooki]

Guess you are right, that makes sense. The term I find really confusing is "core" though. I was convinced it is the same as "strand", but apparently that's not so.

I personally don’t like the term “core” for a conductor, but it is not uncommon. I think “conductor” is much better, especially in light of cables that have other types of cores, for example a polymer fiber for strength. (I.e. “core” in the sense of DE “Kern”.)

There is no ambiguity in English electronics about what the strands are called, though: strands.

[tooki]

I havent read the text before the table, it seems to be the common internet generation disease   
Each core (âme) is composed of many stands (brins), so if you have 3 cores of 24AWG in the same wire (fil) the current is derated from 3.5 to 2A.

Well, almost: if there are multiple conductors, then it is a cable, not a wire. (As I said before: cable and wire are NOT synonyms in electronics!!!)

But yes, the current per conductor is derated to 2A in your example.

Also, thank you for sharing the French words — I don’t know nearly as much technical French vocabulary as I would like! (French was my favorite foreign language in school. I used to be really good at it, but I am out of practice.)

Should you say if the current rating of my 0.035mm² Mogami 3316 will suffice for a subminature camera module ?

Did you say how much current the camera needs? (I don’t see it right away, but I’m on my phone so don’t have the entire thread visible while replying.)

0.035mm² is approximately 32AWG, which many ampacity tables don’t have recommendations for, but this one from JST suggests 0.3A maximum at that gauge, for a 60°C rating.

https://www.jst.fr/doc/jst/pdf/current_rating.pdf

Wikipedia says 0.53A at 75°C rating (i.e. a 45°C temperature rise above 30°C ambient).

Also, at 0.538 mΩ/m, at 500mA you’ll have a voltage drop of .25V across a meter cable. No problem if the 5V power supply is on the higher side of the tolerance range, but potentially an issue if the power supply is on the very low side for some reason.

[Coordonnée_chromatique]

For the French people : conducteur = Âme

Cable = ensemble de fils, cable = wire assembly
Fils = ensemble d'âmes, wire = conductors assembly
âme = ensemble de brins, conductor = strands assembly

Is my terminology right ? 

[Coordonnée_chromatique]

I havent read the text before the table, it seems to be the common internet generation disease   
Each core (âme) is composed of many stands (brins), so if you have 3 cores of 24AWG in the same wire (fil) the current is derated from 3.5 to 2A.

Well, almost: if there are multiple conductors, then it is a cable, not a wire. (As I said before: cable and wire are NOT synonyms in electronics!!!)

But yes, the current per conductor is derated to 2A in your example.

Also, thank you for sharing the French words — I don’t know nearly as much technical French vocabulary as I would like! (French was my favorite foreign language in school. I used to be really good at it, but I am out of practice.)

Should you say if the current rating of my 0.035mm² Mogami 3316 will suffice for a subminature camera module ?

Did you say how much current the camera needs? (I don’t see it right away, but I’m on my phone so don’t have the entire thread visible while replying.)

0.035mm² is approximately 32AWG, which many ampacity tables don’t have recommendations for, but this one from JST suggests 0.3A maximum at that gauge, for a 60°C rating.

https://www.jst.fr/doc/jst/pdf/current_rating.pdf

Wikipedia says 0.53A at 75°C rating (i.e. a 45°C temperature rise above 30°C ambient).

Also, at 0.538 mΩ/m, at 500mA you’ll have a voltage drop of .25V across a meter cable. No problem if the 5V power supply is on the higher side of the tolerance range, but potentially an issue if the power supply is on the very low side for some reason.

"âme" is a polysemic word in french it can also be translated as "soul" in english

[tooki]

For the French people : conducteur = Âme

Cable = ensemble de fils, cable = wire assembly
Fils = ensemble d'âmes, wire = conductors assembly
âme = ensemble de brins, conductor = strands assembly

Is my terminology right ? 

No.

In the context of electronics:*

A wire is a single conductor, which can be solid wire (a single strand, so to speak) or stranded. It can be bare wire, but more commonly it is insulated.

A cable contains multiple conductors (solid or stranded wires, with mandatory per-conductor insulation) within an overall insulation (the jacket). The conductors can be subdivided into groups (like the twisted pairs in Ethernet cable), can be shielded individually or in groups (like in many audio cables, or the mini-coaxial cables inside a high-speed USB 3.2 cable).

Can you give an example of a cable where in French you would distinguish between cable and fils?

(To me, fils sounds like the English word “cord”, which is a more informal word for a cable.)

*I explicitly say “electronics” because usage in the electrical distribution system may be different, and the usage outside of electricity (for example, in jewelry or in wires/cables used for mechanical support) can be very different.

[ebastler]

"âme" is a polysemic word in french it can also be translated as "soul" in english

Surprisingly we have the same duality of meaning in German, although the word clearly has a different origin: "Seele" is German for soul (in the spiritual sense). But the innermost strand of a cable or of a rope is also called its "Seele".

English "soul" and German "Seele" have the same origin obviously. But I don't think "soul" is used in that technical sense for roap or cable parts?

[tooki]

"âme" is a polysemic word in french it can also be translated as "soul" in english

I know.

Interestingly, German uses its word for the soul (Seele) for the flux core in solder wire. So the German word for “flux core solder” literally translates to “solder wire with flux soul”. Kind of poetic in a way!

[tooki]

English "soul" and German "Seele" have the same origin obviously. But I don't think "soul" is used in that technical sense for roap or cable parts?

To the best of my knowledge, no. But I wouldn’t be surprised to hear that it exists (or used to exist) in jargon-heavy contexts like nautical terminology. (A quick dictionary search is not producing any such indications, so possibly not.)

[TimFox]

As you carefully stated, that is the distinction between "cable" and "wire" in electronics.
(A quick check on standard dictionaries shows that some dictionaries confuse cable and wire in electrical applications.)
In other technical English, "cable" is the normal term in mechanical engineering for a multi-strand assembly of fibers used for high tensile strength requirements, as in elevator cables, where a single solid strand would not be flexible enough.

[tooki]

For the French people : conducteur = Âme

Cable = ensemble de fils, cable = wire assembly
Fils = ensemble d'âmes, wire = conductors assembly
âme = ensemble de brins, conductor = strands assembly

Is my terminology right ? 

I just looked over the French Wikipedia, and it defines âme as being the conductor within a fil. So it seems that “fil” just means an insulated wire. The fil can be “monobrin” (solid wire) or “multibrin” (stranded wire). And the conductors in a cable can be referred to as âmes or fils.

(Fil is also the word for sewing thread and yarn, and for dental floss, right?)


In English, in the context where the distinction is needed (like discussing the geometry of a wire in order to configure a wire stripping machine or crimping tool), then we call the conductive inside part of an insulated wire the “conductor”.

But in the context of a cable, “conductor” just means an individual insulated wire.

So here’s my best guess for the definitions :
When describing insulated electrical wires:
1. âme = conductor = the metal part of a wire, inside the insulation. Can be solid (monobrin) or stranded (multibrin).
2. fil = wire = a conductor and its insulation
3. cable = cable = a bundle of 2 or more wires with an overall insulation

And apparently in both French and English, we can use (1) and (2) interchangeably when describing the individual members within a cable.

When describing bare (uninsulated) electrical wire:
fil = wire = a single conductor
no cable is possible, since multiple wires without insulation simply form a larger wire, since they are a single conductor