USB Socket on Laptop

I worry about using the socket for charging in case the lead develops a short.
What would happen if I did plug in a shorted lead or a faulty device to the 5v USB supply? Is there any protection?
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DerbyBorn pretended :

USB outlets are current limited to a set maximum output, so no damage would ensue from them being shorted or any attempt to overload them.
Some are capable of 500ma, 1amp, or even more. 500mA is common on PC's and laptops. The devices you plug in also have their own current input protection, so a device which perhaps needs 500mA will draw that and no more, even if plugged into a USB outlet of 3amps capability.
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On 12/08/15 09:37, Harry Bloomfield wrote:

Subject to more recent changes, the USB power delivery spec limited current to 100mA unless the device negotiated a higher amount.
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DerbyBorn wrote:

Some machines measure the current, and shutdown the port and display an "over-current" warning if a device takes more than the amount it has negotiated (I've not seen that behaviour for a few years though) I presume most have polyfuses these days.
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On Wed, 12 Aug 2015 09:39:19 +0100, Andy Burns

My Dell puts up a balloon notification on the taskbar when a USB port draws too much current.
The first PC I owned that had USB support had 22mm wire ended glass fuses soldered onto the header PCB!
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On 12/08/15 09:18, DerbyBorn wrote:

In a computer the socket is well protected against most common eventualities.
Wall wart chargers vary considerably!
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On 12/08/2015 09:18, DerbyBorn wrote:

I *sometimes* think about wear and tear on the socket although I have never had one fail.
Thanks to the EU, I now have plenty of USB wall warts, most of them nice small switched mode supplies so I generally use these.
But as others have said, I'd have no concerns about charging from the laptop if necessary from the protection viewpoint.
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On Wed, 12 Aug 2015 11:08:37 +0100

I had a thumbdrive which wore out its blade contact, either that or something got loose inside; but as it was a solid item, I doubt that, so I think it was the connector. It got lots of use, too, so wearing out was not a big surprise.
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Yes.
What has this got to do with DIY?
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(='.'=) Bunny says: Windows 10? Nein danke!
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escribi?:

A PC group are too focused on software rather than electrical practicalities.
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Pretty feeble.
Try uk.comp.homebuilt.
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(='.'=) Bunny says: Windows 10? Nein danke!
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escribi?:

I would feel obliged to trawl through months of questions to see if it had been covered. I have a good recall of what I have already seen on this group.
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On Wed, 12 Aug 2015 11:47:13 +0100

It's a lot more D-I-Y than a journey through Sellafield. Unless you have your own nuclear reactor, that it. Or problems with iPhones, or nostalgia, aka the Good Old Days. Or many other subjects that get covered on this NG. Why pick on this one?
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On 12/08/2015 09:18, DerbyBorn wrote:

Yes, the power is disconnected, and you get a warning on screen telling you that a device is drawing more than the allowed amount of current.
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Well my old Dell tells me that the current on the usbhas exceeded the supply limit and I need to buy a self powered hub to plug other things in to it. Brian
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Thanks Brian - and mine is a Dell - an Inspiron N5010.
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