51–60 of 146 posts
Clicking the link to the item[1] on the review page leads to a 404.
[1]: https://www.amazon.com/SurjTech%C2%AE-Standard-Adapter-Devic...
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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…
HN has previously had a story on the author, a Google engineer who tests USB-C cables on Amazon to make sure they're spec-compliant. He does some amazing work: https://news.ycombinator.com/item?id=10508494 I don't have any devices right now that use USB-C, but whenever I see a deal pop up for one, I usually check the Amazon listing to see if this guy has reviewed/certified the cable yet. I recommend others do the sam…
Another user has compiled Benson's reviews into a Google spreadsheet: https://docs.google.com/spreadsheets/d/1wJwqv3rTNmORXz-XJsQa...
USB-C seems like a really bad standard if the cable can destroy expensive electronics. EDIT: Even if the cable is wired and built correctly (which is apparently difficult for manufacturers to get right), cables fray and tear all the time. I foresee a lot of dead electronics upcoming.
As for cables fraying, the most common result is an open (an unconnected wire). If two of the wires get damaged at the same time, you might get a short (and the USB standard mandates that a short causes no damage to devices). But reversing a pair of wires? It's ridiculously unlikely that fray and tear on a cable not only severs a pair of wires, but also reconnects them backwards!
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unless the connector were cut, or some other catastrophic failure. I tend to think ruining a devices USB controller should be near impossible short of something like the USB killer ( http://arstechnica.com/security/2015/10/usb-killer-flash-dri... )
I was playing with a FTDI (a clone :D) and an Arduino and accidentally mixed up VCC and GND from an external power source. I only realised because Minicom was failing to connect to the device. Then I realised what I had done, I tried removing it from the USB port and putting it back in, but it wouldn't work. I then tried a mouse too, but that wasn't working either. Thinking I'd killed a USB port on my Mac (well there…
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.
Breaking test equipment should probably force a recall by itself. I wonder what the Amazon procedure is for reporting faulty items?
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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…
> 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. No, for C-to-C connections, the resistance is provided by the host ("downstream-facing") port, not the cable. The resistor in an A-to-C cable is basically emulating the signal that would otherwise be provided by the host. There's no such thing as a "1.5A C-to-C cable"; all type-C cables are required…
4.11 could really use a massive cleanup for readability it seems.
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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…
Sure, but the magnitude of that cost matters a lot. You were saying a dollar or two in raw materials to protect against 100W, now you're saying three or four cents. A few cents to protect hundreds of dollars in equipment from electrical faults seems worthwhile to me.