Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

USB-C is about to go from 100W to 240W, enough to power beefier laptops

theverge.com

Post reply on HN
Print view View original

231–240 of 498 posts

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#231

Post by wearywanderer »

Klinky wrote: post #228
wearywanderer wrote: post #218

Earlier quoted context omitted.

> People already incorrectly buy USB A when they should have bought USB C or visa versa. Changing the physical form-factor doesn't solve this problem. At least the nature of the problem is immediately apparent to such people the moment they attempt to plug the cable in. If the cable won't fit, they know there is nothing wrong with their computer; they didn't misconfigure anything or click the wrong button. The proble…

Except people have damaged ports forcing incorrect form factors. Also we've had tons of other standards where cables vary with performance. HDMI, DisplayPort, IDE, USB1/2/3. You'll get people complaining about the cable not working with their new device, and then people complaining it didn't work with their old device. Eventually USB-C will be so capable and ubiquitous, this will be a non-factor. I don't miss the day…

I would love to see somebody attempt to damage a micro-USB or USB-C port by forcing a USB-A plug into it. Not going to happen, sorry. They may as well try to force a NEMA-5 plug into a VGA port. It's nonsensical.

At a certain point on the usability continuum, user error becomes so severe that only dementia can explain it. But USB-C incompatibilities are so far from that point that arguing otherwise seems like bad faith. These USB-C incompatibilities can bite technically inclined people with sound, sober and healthy minds.

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#232

Post by Dylan16807 »

grlass wrote: post #146
ohazi wrote: post #141

Earlier quoted context omitted.

Indicator recommendations are routinely ignored. There are already color codes for type-A ports, and there's the "lightning bolt" indicator for Thunderbolt USB-C ports, but PC manufacturers ignore them when they want their laptops to have a certain look and feel (e.g. gaming laptops want red or green everything, Apple wants aluminum everything, etc.). Cable manufacturers are going to do whatever is cheapest.

Yeah, it's a bit of tragedy. Resistor style stripes on cables would be fun, a stripe for each feature such as bandwidth, power, etc; perhaps already suggested (and ignored). Though complement for ports would be trickier. Embossing symbols in the style of thunderbolt might be the way to go, even if the standard is not fully adopted.

> each feature such as bandwidth, power, etc;

Honestly that's about all you need.

Even just a bandwidth indicator would be suitable 90% of the time.

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#233

Post by manmal »

leoc wrote: post #91
dijit wrote: post #16

Earlier quoted context omitted.

I mean, I share that worry, but isn’t the “-PD” part of “USB-PD” a negotiation step? I have very little worry that my carpet can accidentally negotiate 60w and up. I _am_ worried about cheap USB-PD devices that forgoe this negotiation as it is complex and expensive to implement.

> I _am_ worried about cheap USB-PD devices that forgoe this negotiation as it is complex and expensive to implement. Yes. Moving critical safety limits into software ? https://en.wikipedia.org/wiki/Therac-25 Let's hope they're all up to the challenge ...

How would power negotiation be implemented without software?

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#234

Post by salawat »

asdff wrote: post #122
salawat wrote: post #40

Earlier quoted context omitted.

Because most desktops don't have integral screens and keyboards. Nor do they stay on and compute in an albeit degraded state in transit. Not everyone is just using laptops as a word processor/browser. Sometimes you just need oomph.

i would love if my macbook stayed on and computed when i closed the lid. behavior is pretty inconsistent no matter what settings i check in control panel. sometimes i close the lid and it holds its ssh connections, sometimes it drops them and i don't know why.

Can't help on the lid closure, but apparently there's some screensaver setting that tells the system to keep working in the background even when the lockscreen appears after screensaver activation.

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#235

Post by tgv »

lmilcin wrote: post #121

5A, 50V Good luck. USB port just isn't physically ready for this. This is going to end with some spectacular fireworks once you factor in cheap Chinese engineering for cables, ports and chargers.

BTW, does anybody know if that's safe? The numbers I remember are an order lower (24V, and less than 500mA).

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#236

Post by contriban »

alerighi wrote: post #216
skybrian wrote: post #174

Earlier quoted context omitted.

It actually is sort of nice, because "works" isn't binary. It's nice to be able to charge a laptop with what you have, even if it doesn't charge quite as fast. You can transfer data over a cable at lower speeds even if it doesn't run at top speed. Using the "right" cable is performance optimization. This isn't like the old days when plugging things in the wrong way might damage your machine.

Not using the proper cable could lead also to fires, for example. We are talking about a significant amount of current. If you don't use a cable rated for that current, the cable or the connector will overheat, and possibly start a fire. And it's not a remote possibility. It happened to me with a fast charging phone power supply and the phone, and the cable was the one provided by the manufacturer! The type-C connect…

From what I understand, the cable has to advertise the supported power output, it’s not like a raw power outlet that will start a fire if you use a random thin cable. A 5W USB cable will probably never receive 240W, even by mistake.

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#237

Post by lmilcin »

mnouquet wrote: post #176
lmilcin wrote: post #121

5A, 50V Good luck. USB port just isn't physically ready for this. This is going to end with some spectacular fireworks once you factor in cheap Chinese engineering for cables, ports and chargers.

I bet people downvoting you don't understand physics... :-/

Shh... it is not in good tone to directly demask shortcomings of general HN audience. Everybody here is an expert in every topic discussed and if you got downvotes it means you have deserved it.

I personally own an electronics lab but whaddaiknow.

On more serious note, the USB-C just barely has dimensions to deal with 5A 50V. You need thick enough cables and traces, you need clearences and you need margins.

If you look at breakdown voltage for USB C connector, it is not a lot above 50V. Usually, you would want many times your working voltage. It just begs for a tiny speck of dust or condensation, manufacturing fault, bent connector, etc. to cause bad day for the owner.

Now, in a properly designed device, it technically should immediately detect the situation and cut the power. But there are two catches. One, is that at that power the short might be just about right resistance for this safety to treat is as valid. Second, this assumes properly designed device. If you cheap out on silicon you use for your charger it might just not have the capability to stop it before it gets to far and melts a bunch of stuff.

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#238

Post by manmal »

r00fus wrote: post #59
jeffrallen wrote: post #7

Plus, if you thread the cable through your hot dog, it will be warm in time for lunch. Meanwhile, Apple's M1 chip is showing us that 240 watt laptops are the problem, not the solution...

Clearly there are non-computing use-cases for 240W devices that would benefit from being charged. What about power tools, or high-end game consoles?

There’s an alternate universe where all wall power outlets are USB-C with ethernet already mixed in.

Re: USB-C is about to go from 100W to 240W, enough to power beefier laptops

#239

Post by lmilcin »

tgv wrote: post #235
lmilcin wrote: post #121

5A, 50V Good luck. USB port just isn't physically ready for this. This is going to end with some spectacular fireworks once you factor in cheap Chinese engineering for cables, ports and chargers.

BTW, does anybody know if that's safe? The numbers I remember are an order lower (24V, and less than 500mA).

They want 240W. 5A times 50V is 250W. It means that you can't have both voltage and current lower, you can only lower one by increasing the other. But both higher voltage and higher current are a problem.

More voltage will require larger clearances and better safeties (like thicker isolation on cables).

"In industry, 30 volts is generally considered to be a conservative threshold value for dangerous voltage. The cautious person should regard any voltage above 30 volts as threatening, not relying on normal body resistance for protection against shock." https://iastate.pressbooks.pub/electriccircuits/chapter/chap....

Now, if the voltage is dangerous, it stops just being problem for the device but becomes safety hazard with all implications.

On the other hand increasing current is not without problems. It quickly requires thicker cables and traces for which space is just not available in tiny USB C connector. If conductor is not thick enough the result is heating and possible melting, degrading the material over time which could lead to shorts.

Post reply on HN