There is a reason for USB-C extensions not to be part of the standard. They can be bothersome in the best case and dangerous in the worst.
There is a reason for USB-C extensions not to be part of the standard. They can be bothersome in the best case and dangerous in the worst.
Anybody care to sum this up for people who can’t watch videos?
So a standard cable needs to be chipped to show its rating to the device, its not that the device can pull what it wants or can get, but the cable itself tells it what it can supply. Extension cables can’t do that, because it doesn’t know what it’s plugged into, and that would be if they even bothered to put a chip in. They instead piggy back off the chip for the main cable. The problem comes when you you have a 240 watt cable hooked up to a cheap 120 watt cable, with the device being told it can push 240, and starts to super heat the extension cable
Brilliant thanks
5 sentences that inexplicably need a 9 minute video to say
Fuck YouTube
Haven’t you heard about Raid Shadow Legends?
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This sounds solvable, doesn’t it? Have the extension cable have a chip saying it can do X at maximum, then compare with whatever is to be extended and communicate the minimum of both upstream. Might not become a sleek cable-like design, but would extend the 240W cable with the extender safely staying at 120W
Well, the source checks the cable using the CC line which doesn’t go through the cable (VCONN). So source only knows the cable directly plugged in. To make the extension cable visible, the sink would be required to check the cable plugged in using VCONN and then the tell max ampere to the source over the other CC that goes through the cable.
2 Problems:
Sink devices normally don’t read or can’t read VCONN as far as I know
No way of detecting if a third cable (extension in the middle) is present and what specs it has
Soon on Amazon…
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Well I’m glad I know that now.
Pretty much this, thanks for the summary
Correct, except for your example. Firstly, 120 watt USB c cables don’t exist, only 60w, 100w, 140w and 240w. And only plugging in a 100w or higher cable into a 60w extension would be dangerous, since it would allow drawing 5 amps on a cable over an extension only designed for 3 amps. However, as soon as your extension is rated for 100w it is completely safe to use with any USB c cable, even those rated for 240w, as those only operate at a higher voltage but still only allow 5 amps max.
I have also never seen an USB C extension cable rated for less than 100w, so this is kind of a moot point. If 60w usb c extensions exist somewhere, they would indeed be dangerous, but I have never come across one
Interesting, I’d never trust any USB cable to push anywhere near 100 watts anyway haha good god, the most I ever do is maybe 20w at 5v.
I’ll keep that in mind when buying cables in the future though this is very useful info!
If you buy a Steam Deck, or the Lenovo laptop I have for work, the only charging options you have are USB C. Their standard chargers put out at least
6045 W, and they aren’t particularly special. In fact, I’m pretty sure 20 W at 5 V won’t be enough to supply these while in use, so you will either be using battery with long charge times in between, using them with battery-assisted power for longer use times until you hit those long charge times, or using the6045 W or more at whatever voltage the chargers provide.The Steam Deck charger is 45W.
While this is handy to know, it doesn’t negate my point.
My laptop can do 240W over USB-C, I’m just waiting for a charger that can do it with a modular cable
It has a 240w charger but have you checked to see that it’s using all 240w?
Most laptops use (up to) 120w.
It can use almost all of it using the GPU
What’s the make and model of the laptop?
Framework 16
Site says the power adapter is 180w
https://frame.work/blog/framework-laptop-16-deep-dive---180w-power-adapter
How did we possibly survive with entirely dumb power chords?
“Dumb” power cords have thicker gauge wire than USB-C cables and much larger contacts.
This is not about contacts but cableburning tho.
Hence the thicker gauge wire.
Going to take a wild guess and say the same reason you shouldn’t chain extension cords. USB can carry over 200w these days.
what if I don’t know that either
It all depends on current draw vs wire size over distance.
No, that’s not the reason at all. The actual reason is a phenomenon called “loop impedance”, which increases exponentially with each additional plug connection you chain together, regardless of the wire guage and distance of the extension
Too high loop impedance can cause your RCD to no longer trigger if you accidentally touch an exposed live connection, which is a major electrocution risk
Are you referring to AS/NZS 3000? I’ve never come across that here in the states, that’s some interesting reading and makes perfect sense.
On the practical side without engineering calculations, daisychaining extension cords will simply exacerbate voltage drop, which coupled with increased line resistance, will just cause increased current draw and increased thermal dissipation on the cord (those cords everyone’s dad has where the outer jacket is shrunk to hell against the internal wires), and poor reactance of (especially motor driven) equipment. This can be alleviated by using thicker cords (eg #10), but it still has limitations over excessive distance. A small battery charger will probably continue to work, whereas a table saw will have problems.
On the safety side, even sticking your finger on the load terminal of a 20a breaker will not trip it, even barefoot, as the human body doesn’t draw enough current, it just zaps the hell out of you. OCPDs are typically designed for system and equipment protection. GFCIs are more effective at protecting a person, but only if the current deviates to a different ground path. As far as I can tell from preliminary reading, the purpose of calculating loop impedance is determining the effectiveness of the grounding (earthing) conductor in relation to distance from the actual transformer. In a real world scenario, this is more going to be say if a cord were to be cut or equipment faults to ground, and whether the impedance exceeds the physical limitations of the wire to trip the breaker (or fuse).
Extensions aren’t part of the official spec, so they aren’t actually certified as proper USB-C.
Same risks as any other janky no-name gear you see online, even if it SAYS it’s rated for a specific throughput or power rating, that may not be the case.
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This is what AI says about this video:
You’re a bold one. Lemmy hates videos and AI both.
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I asked the AI if it was wrong or you were wrong. It said you were wrong.
Who am I to believe?
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I’m sick of stuff that should be ~2 paragraphs of text being a video. I do not want to watch a person or hear a narrator, I interpret written information much more effectively, and being text I can retain significant portions of the document as necessary.
Strangers passing in the street
By chance two separate glances meet
And I am you and what I see is me
You know, you don’t have to watch it. You can find the information elsewhere in text format. But I guess we all need to conform to your preferences.
It’s nice that you’re so ready to delegate to my natural authority, but unnecessary.
Well I prefer the video. So make sure you watch it. Give a like as well.