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Bad USB-C cable destroys laptop

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Re: Bad USB-C cable destroys laptop

#101

Post by bsder »

totalart9000 wrote: post #66
bsder wrote: post #56

Earlier quoted context omitted.

Use ... a ... hub. If you're doing lab work, it's really easy to get weird potentials on various lines. I almost never plug anything like an Arduino directly into my laptop without a powered hub in between. I assume I'm a klutz. So, I take steps to minimize the damage when something happens.

Anyone have a hub to recommend? I have a hub which I bought for cheap on eBay which I use on my desk for keyboard, mouse and similar but would not trust that hub to offer much if any in way of voltage protection so I'd like to know about safe hubs for lab use.

Just about any externally powered hub is fine. As long as you're plugged into the wall, it's going to help dramatically if something stupid happens.

Personally, I've switched over to using USB 3.0 hubs. They supply more power and seem to be better built.

Re: Bad USB-C cable destroys laptop

#102

Post by userbinator »

CydeWeys wrote: post #50
digi_owl wrote: post #29

Earlier quoted context omitted.

Frankly the C plug spec seems overly convoluted. Each cable needs one of 3 resistors depending on them being a A/B-to-C cable, 1.5A C-to-C cable, or 3A C-to-C cable. Note that the A-to-C cable may well be able to carry 3A, but it shall never use the 3A C-to-C resistor (what many of the cables he find as faulty does). Note that all this resistor shenanigans are all independent of the Battery charging spec that has bee…

USB-C does lots of things, including high voltage charging, backwards compatibility, and reversible orientation. Yeah, you could make it simpler, but then you'd have to start giving up some of those features, at which point now you've just reinvented USB-A again. It's just as complicated as it needs to be. And for godssakes, the pin-out diagram isn't that complicated; it only has 24 pins! There's no excuse for flippi…

"only" 24 pins? That's still 6 times more than the previous standard...

Re: Bad USB-C cable destroys laptop

#103

Post by kevin_thibedeau »

krapht wrote: post #47
mikeash wrote: post #31

Earlier quoted context omitted.

If you stop the current from flowing, you don't have to shunt any power anywhere. You'd have to open the circuit in the face of 5V of potential hooked up backwards, not really a tall order.

I don't want to be a broken record, but you're right, not a tall order, but no it's unreasonable on account of cost. It's impossible for USB C to be hooked up backwards by its mechanical design, so why guard against it? The high-side transistor to prevent reverse polarity faults could be 3 to 4 cents in manufacturing cost! It's also not trivial to make sure that transistor trips fast enough to prevent all your low-vo…

> t's impossible for USB C to be hooked up backwards by its mechanical design, so why guard against it?

Because cabling can fail in other ways. A short could be caused by mechanical damage to the cable anywhere along its length. It would be nice to have a host that doesn't burn up in those scenarios seeing as they are already required to protect the bus.

Re: Bad USB-C cable destroys laptop

#104

Post by nitrogen »

xur17 wrote: post #54
plorg wrote: post #15

Earlier quoted context omitted.

Another user has compiled Benson's reviews into a Google spreadsheet: https://docs.google.com/spreadsheets/d/1wJwqv3rTNmORXz-XJsQa...

And a website: https://usbccompliant.com

Do those affiliate codes support the original reviewer guy, or just the operator of the website (if they are different people)?

Re: Bad USB-C cable destroys laptop

#105

Post by krapht »

kevin_thibedeau wrote: post #103
krapht wrote: post #47

Earlier quoted context omitted.

I don't want to be a broken record, but you're right, not a tall order, but no it's unreasonable on account of cost. It's impossible for USB C to be hooked up backwards by its mechanical design, so why guard against it? The high-side transistor to prevent reverse polarity faults could be 3 to 4 cents in manufacturing cost! It's also not trivial to make sure that transistor trips fast enough to prevent all your low-vo…

> t's impossible for USB C to be hooked up backwards by its mechanical design, so why guard against it? Because cabling can fail in other ways. A short could be caused by mechanical damage to the cable anywhere along its length. It would be nice to have a host that doesn't burn up in those scenarios seeing as they are already required to protect the bus.

Like other comments have mentioned, a short is not a voltage reversal. The methods to alleviate them are different. As the connector is polarized, the only way to get a voltage reversal is for something seriously strange to happen either at the power supply end or the cable.

If it is at the power supply end, all bets are off. If your USB charger fails short prepare for mains voltage to absolutely fry anything and everything connected to it and a negative voltage is the least of your worries. In the cable, a miswiring is seriously negligent and I see no reason why it should be designed around.

Re: Bad USB-C cable destroys laptop

#106

Post by nerfhammer »

rcxdude wrote: post #96
klodolph wrote: post #87

Earlier quoted context omitted.

USB overcurrent protection is pretty sophisticated. Devices get 100 mA for free, then have to ask the host for more current. Well, it's a bit more complex nowadays, but that's the basics.

I'm not sure if there are many devices which actally follow that spec to the letter (in either direction). Usually the USB ports will just allow 500mA (or whatever they're designed to provide) plus some fairly generous overhead, regardless of what the device has asked for, and assuming they bother to implement overcurrent detection at all.

I believe macs give you 500ma for free

Re: Bad USB-C cable destroys laptop

#107

Post by kentonv »

simoncion wrote: post #95
kentonv wrote: post #40

Earlier quoted context omitted.

Honestly G+ is amazing for technical discussion. Examples from my feed: https://plus.google.com/+KentonVarda/posts/cFsgVBuXinb https://plus.google.com/+KentonVarda/posts/JDwHfAiLGNQ At least in my experience, FB and Twitter simply don't produce anything like that.

> Honestly G+ is amazing for technical discussion. If and only if you're okay with the horribly limited formatting that Plus offers. There's no way in hell you can ever post code snippets, for example.

Code snippets are reasonably OK ever since they made indentation work, which was like 4 years ago.

Re: Bad USB-C cable destroys laptop

#108

Post by eklavya »

kstenerud wrote: post #81
bsimpson wrote: post #33

Earlier quoted context omitted.

I bought one of these recently, based on Benson's endorsement, for my Nexus 5X: http://smile.amazon.com/dp/B018F8BGLA It's worth noting that the Nexus 5x doesn't do USB 3.1, so even if you get a fancy Super Speed cable like this one, you are still suck with slow charging from your computer's USB A port.

The Nexus 5X supports the new 15W fast charging USB-C standard . It takes about 15-20m for my phone to go from empty to full from the wall charger, and considerably longer from a USB A port.

I think something is broken on mine then. It takes an hour and five ten minutes to go from 15% to full from a wall charger. Are you sure it only takes 15-20 mins?

Re: Bad USB-C cable destroys laptop

#109

Post by simoncion »

XorNot wrote: post #99
simoncion wrote: post #94

Earlier quoted context omitted.

> It makes things more expensive than they have to be. Consumer electronics are -generally- ridiculously cheap these days. I welcome more "overengineering", even if it drives up the cost somewhat. :)

The problem is cost != quality in any reliable way any more.

That's an entirely separate issue from the one that my comment speaks to. :)

Re: Bad USB-C cable destroys laptop

#110

Post by [deleted] »

eklavya wrote: post #108
kstenerud wrote: post #81

Earlier quoted context omitted.

The Nexus 5X supports the new 15W fast charging USB-C standard . It takes about 15-20m for my phone to go from empty to full from the wall charger, and considerably longer from a USB A port.

I think something is broken on mine then. It takes an hour and five ten minutes to go from 15% to full from a wall charger. Are you sure it only takes 15-20 mins?

[deleted]
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