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

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

#271

Post by MinorTom »

chrisacky wrote: post #209
andrewmunsell wrote: post #182

Earlier 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…

Even I have this problem. I bbought an amp reader and throw out anything reporting below 0.4ma/h. So many devices come bundles with poor cables my house is riddled with cables that I just never want to use for charging. I'm actually TERRIFIED of pluggin anything in to my kids Switch other than Nintendo's official cable, incase I brick i t. Does anyone know if they've patched this? I have some Dell laptop charger USB-…

The Switches USB-C implementation is genuinely broken, so this isn't the fault of the connector. A spec-compliant charger, cable and connector will never brick anything (or catch on fire, for that matter)

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

#272

Post by a1369209993 »

asdff wrote: post #112
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...

On the other hand, I would love to use an M1 chip that makes use of 240 watts. Could you imagine the power? Give me the option to trade efficiency for horsepower. When I hear things like "My M1 mac never turns on the fans" I wonder why the system isn't clocking higher if the cooling system is running so comfortably.

> why the system isn't clocking higher if the cooling system is running so comfortably.

Because there's a upper limit on how much power (voltage, clock rate, etc) you can shove though a CPU before it starts malfunctioning or getting damaged by purely electrical effects, no matter how effectively it's cooled?

It's entirely possible Apple has set the nominal limits fraudulently low for business reasons, but there are actual physical limits here, and depending on how the CPU is designed/optimized, it's quite possible that it's easy to build a cooling system that significantly exceeds what those limits allow to be demanded of it in a significant range of cases.

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

#273

Post by neither_color »

Rebelgecko wrote: post #148
neither_color wrote: post #132

Earlier quoted context omitted.

And every time I buy a new device and think I'll be able to use my existing USB-C cables I'm met with a new standard. Bought a new external GPU enclosure? My macbook charging cable wont work I need a 40gbps thunderbolt THREE(not 2) cable. Bought a new Oculus Quest? Neither my egpu or macbook cables work I need an $80 LINK cable.

My Oculus Quest works fine with a 3meter AmazonBasics USB cable that I got for like $15. I think the only advantage of the official link cable is that it gets you 5m without needing to add an extender to a 3m cable

It works but it if you run a high bandwidth game like Flight Simulator you might hit some performance limits, you can check your cable speed in the quest desktop app.

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

#274

Post by jws »

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.

Of the 415 pages in the spec, 8 of them are devoted to arc mitigation in the "USB PD High-Voltage Design Considerations" section.

Lots of discussion about detecting unplug and limiting slew rates. In practice that will cost pennies to implement and will therefore be skipped in many designs. ("I got a great deal on this charger on Amazon!")

Time to develop some user superstitions around USB C:

"The withdrawal velocity is a factor in whether an arc will occur or not. If it is fast enough, then there is insufficient time to reach the voltage differential needed to form an arc. In practice, the withdrawal rate may not always be fast enough to keep the differential voltage below the threshold of arcing."

So, tell your informal tech support clients (family and friends) that they just didn't unplug their cables fast enough when their cables and devices start breaking. I look forward to everyone's sleight of hand moves where they unplug cables so fast you can't see it.

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

#275

Post by Ekaros »

lmilcin wrote: post #237
mnouquet wrote: post #176

Earlier quoted context omitted.

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 lo…

Reminds me of those lovely "molex" to SATA power connectors. And in my marginal lay persons mind they should be superior for transferring currents. And still some of them don't fare exactly well, with lower current draws...

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

#276

Post by throaway46546 »

dangerlibrary wrote: post #243
dragontamer wrote: post #219

Earlier quoted context omitted.

> We are talking about a significant amount of current. Are we? I'm not sure how they deliver more power in this specification. But traditionally, the additional power (from 5W to 20W to 100W) was through additional *voltage*, not current. > And it's not something trivial that power supplies and phones can detect, there is not a way to determinate the voltage drop in the cable built into the standard (basically all t…

> Voltage can't go up arbitrarily, but voltage can safely be increased to ~48V or so in most applications. After 48V, humans start to get shocked / hurt, so that's probably the reasonable limit. Car batteries in ICE cars are nominally 12v. Grab both terminals and tell me it doesn't hurt.

It just tingles a bit if anything.

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

#277

Post by modeless »

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…

> Not using the proper cable could lead also to fires, for example

Only if the cable or device is defective or damaged. Which is true of every type of charging cable or connector.

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

#278

Post by Ekaros »

mavhc wrote: post #185
unnouinceput wrote: post #172

Earlier quoted context omitted.

At 5V and your household needs: 1- refrigerator (400W when it motor is running); 2- vacuum cleaner (1000W when running); 3- TV's/PC's/light-bulbs (around 1000W in the evening when all are running at the same time) - all these amounts to at least ~2.5KW power. Now divide that by 5 and you get the intensity at 500A. Do you have any idea how thick the copper would need to be to allow 500A? a full 1cm x 1cm. Any idea how…

Who's running their vacuum cleaner all evening? My fridge/freezer uses 25 watts average, but the 90% of things I was thinking about was ignoring the heaters and motors, just the lights, computers, speakers etc. Next question, why 5V, when they're talking about 50V. That brings us down to 1/10th the amps. Also this is only inside your house, not for power distribution. Generate your DC power with solar, store it in yo…

25 watts might be average, but what is the peak and consumption during duty cycle?

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

#279

Post by zlsa »

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…

It should be impossible for any set of non-damaged, non-defective, spec-compliant set of USB-C cables and peripherals to cause fires. The specifications are very carefully designed to prevent any combination of cables and devices from causing damage.

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

#280

Post by dhdc »

Mountain_Skies wrote: post #255

Does there exist a device that you can plug in USB and HDMI cables and have it tell you what features, modes, etc that cable supports? Seems like having something like that wouldn't eliminate all the problems but would make them easier to deal with by quickly identifying that the cable you tested is or is not appropriate for the task at hand. That aside, I'm looking forward to running my laundry room off of a dozen U…

If you just want to know if a usb cable can safely delivery a certain current, then a cheap multimeter might do.

If you want to test whether a cable will work with a certain protocol at a certain data rate, just plug it in and see if it works. Because the alternative method[1] costs hundreds of thousands of dollars.

[1]https://www.keysight.com/ca/en/products/bit-error-ratio-test...

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