> "while my own Dell XPS 15 can technically charge over USB-C, it needs 130W of power to charge and run at full bore simultaneously."
Meanwhile, my M1 MacBook Air can charge and run at full bore on a 20W iPhone charger!
USB-C is about to go from 100W to 240W, enough to power beefier laptops
391–400 of 498 posts
Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops
#392Earlier quoted context omitted.
Explaining to my aunt or uncle or grandparents that, no, the cable and charger they bought isn't the right one for their phone/laptop/whatever even though it fits isn't ideal. Sure, it might just charge slowly (cue family tech support call), but it could also just show "not charging" on OS X for example, which is just confusing for most people. It's a real problem, even if tech savvy people are fine with lower charge…
How is this any different than buying the wrong cable in the past? You used to have to choose USB2, USB3, USB3.x, micro USB, mini USB, DisplayPort, Mini DisplayPort, HDMI, mini HDMI, VGA, DVI, thunderbolt, and more. I think people are either too young to remember this disaster, or have just outright forgotten.
Allow me to say it's slightly different, because you could basically tell the difference by just looking at the connector carefully. The knowledge that if it connects, it'll 99.9% work is too ingrained in all of us. Usb-c breaks that norm.
Now you have to carefully see what the packaging says, which can range from inadvertently unclear to downright misleading. And to add to that, you don't know what to look for in the first place if you don't have prior experience with thunderbolt/usb-c. Example, I didn't know that a cable must explicitly mention DP in order to connect to an external monitor. Because it was the first time I had an external monitor that can use usb-c.
Not really complaining, usb-c is very very nice. Just pointing the minor annoyance of learning its warts.
Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops
#393No. Laptops should all become more energy efficient.
Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops
#394Earlier quoted context omitted.
Is it really undetectable? A smarter USB PD controller and maybe some extra sensors should be able to mostly avoid that problem, no?
Ok, so you detect voltage drop of say 0.4V@5A on the phone end, so slightly out of spec. How do you decide whether it's a slightly underspecced cable (quite common) and 2W being radiated as heat from a 1m long cable (which is not really an issue), or great cable but high contact resistance (where 2W are concentrated into a tiny space that can't cool it)?
You could design a port with multiple contacts onto the same cable pin. One contact does voltage sensing while the other takes the current.
Then any amount of dirt in the connector can cause whatever heating it likes, but the device can always calculate how much heat is being dissipated in the connector.
Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops
#395Earlier quoted context omitted.
If the alternative is starting house fires that sounds pretty reasonable.
The problem isn't whether reputable manufacturers will do it, it's whether the bottom of the barrel cheap cables from eBay/Amazon will do it. The advantage of USB2 is that it's very hard to screw up. The design is so simple that even the cheapest cable is usualy "okay" because making an "okay" USB2 cable is so simple. In contrast, making a USB-C cable is much more difficult, which means unscrupulous manufacturers flo…
The solution would be for devices to test cables before letting them work.
If my iPhone tested the cable was up to spec before charging and said "error, bad cable" if any test failed, then china-cables would be forced to pass all the tests.
Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops
#396I'd like to see the next version of this spec go from 5A 50V to 2A 2000V.
5 Amps is getting into danger territory with cables that are bent a lot and heating is concentrated in one high resistance area. Heating => melting => fire => deadly. Fire kills 10x more than electrocution.
2000V is also well into danger territory for humans, but we now have technology to make it human-safe for a child to gnaw through that wire while in operation and avoid injury. All that's needed is for the spec to require current leakage detection. As soon as 1 milliamp or more is unaccounted for between charger and device, you need to assume it's flowing through a child's tongue and power off within a few tens of microseconds.
That requirement means you need MOSFETs at each device (to be able to power off quickly), and to have capacitance control of the cable.
Every device needs to Verify that the device on the other end and cable does these things, so that nobody can make a cheap cable or widget which kills people.
Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops
#397Earlier quoted context omitted.
It should be impossible for any set of non-damaged, non-defective, spec-compliant set of USB-C cables and peripherals to cause fires. Then there's the crap offered for sale on Alibaba which somebody will resell on Amazon and which will show up on a checkout rack at the gas station. USB-C has very tight tolerances and unusual material requirements. Dirt or water can create a conductive path all too easily with USB-C p…
Yeah but there will always be crap for Alibaba for anything you can think of. The solution would be banning charging altogether and adopt only proprietary standards.
No, the solution for the US would be to refuse imports of any power device that lacks UL/CSA approval.
Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops
#398Earlier quoted context omitted.
It’s because virtually no one outside of Hacker News seems to have these problems. The rest of the world seems to love the singular port.
Wait until you have to do tech support for someone who has a USB-C charging cable that doesn't work connecting their hard drive. Singular cable wasn't in the specs.
Any compliant USB-C cable must support USB 2.0 no matter what. If a USB-C cable isn't working with 2.0 data, then it's a noncompliant cable.
Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops
#399I'd like to see the next version of this spec go from 5A 50V to 2A 2000V. 5 Amps is getting into danger territory with cables that are bent a lot and heating is concentrated in one high resistance area. Heating => melting => fire => deadly. Fire kills 10x more than electrocution. 2000V is also well into danger territory for humans, but we now have technology to make it human-safe for a child to gnaw through that wire…
Is there not technology to check changes in resistance? Even if it is in a small area as it heats it resistance should change much more rapidly than resistance changes when the entire cable heats up.
Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops
#400I genuinely don’t understand how I’ve managed to be so lucky. That is, I absolutely do not disbelieve the many tales of woe I hear on HN (like the many in this thread) - but I’ve literally never put any thought into what cable I plug in to what device, and had no trouble that I can recall. It really had lived up to its hype for me so far. My USB-C devices are: a wireless charger, two MacBooks (one intel, one m1), a P…
I don't think the issues normally present when just charging--I'd say charging is the simplest task. But when I tried to plug a USB C monitor into my mabook the other day I went through every C cable in the house to no avail, despite the fact they all do USB C PD just fine.
For Alternate Mode to work, only cables with high-speed lanes will work (aka USB 3.0 cables). Power Delivery doesn't need these high-speed lanes at all.