Vague question coming up.
A friend has just bought a new desktop, an HP Pavilion All in One 27-XA0XXX.
The (Very inadequate) documentation says that one of the USB ports is 'a charging port'.
Friend claims that a USB Disk plugged into this port 'got quite hot'. She then tried it in another USB port and it didn't get hot.
I've never heard of a USB Charging port. Is there such a thing and, if so, can ordinary USB devices safely use that port without overheating?
I said it was vague.
Thanks
Silverback
USB charging port
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Re: USB charging port
I think this might mean that this port still has power even when the laptop is shut down. So it can be used to charge an external device from the laptop battery when the laptop is not in use.
StuartR
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Re: USB charging port
Ouch! So one is charging one battery from another battery, losing energy as all energy-transfers must, losing battery life in the laptop, too, I would think.
Most laptops have a "mains power" light blinking away, so I assume that although the Power-OFF button has been used, mains electricity is still available. And since the computer hardware can detect when a device is plugged in (else how would Windows know?), it seems strange that the wizards can't come up with a way to pipe that mains electricity "straight-through".
And yes, I recognize that the mains has to be stepped-down, rectified, condensed, resisted etc.
One other thing I don't like is the prospect of waking up dead from a house fire caused by an overheated device.
FWIW I plug my phone into the laptop late at night so that it charges while I listen to the last thirty minutes of music before bed, and so that it continues to charge the instant I turn the laptop ON first thing in the morning.
Cheers
Chris
He who plants a seed, plants life.
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Re: USB charging port
Don't know if it affects this erudite exchange of postings, but the device is a desktop, not a laptop.
Does that make a difference?
Silverback
Does that make a difference?
Silverback
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Re: USB charging port
USB ports must adhere to a standard output voltage, nominally 5V. The output current available varies depending on the port specification.silverback wrote: ↑21 Jul 2020, 22:16Vague question coming up.
A friend has just bought a new desktop, an HP Pavilion All in One 27-XA0XXX.
The (Very inadequate) documentation says that one of the USB ports is 'a charging port'.
Friend claims that a USB Disk plugged into this port 'got quite hot'. She then tried it in another USB port and it didn't get hot.
I've never heard of a USB Charging port. Is there such a thing and, if so, can ordinary USB devices safely use that port without overheating?
I said it was vague.
Thanks
Silverback
A device connected to a USB port will endeavour to take whatever power (current) it requires, and if this exceeds what is available, the USB port should shut down.
Unless the USB port itself is faulty, the power requirements of a USB Disk drive are determined by it, not the port it is connected to. This should mean that if the USB device is getting hot, that is down to the power it is drawing, not what the USB port is delivering. My guess would be that the drive was getting hot because it was in use in the first port, and not in the second.
It may be easier to understand if you think of it like a mains circuit. You have a number of sockets in your house, some of which are protected by a 5A breaker, some by a 13A breaker. If you plug a 100W (approx 0.5A) lamp in to either, the maximum power it can take will be 100W, but it will depend on whether or not it is switched on. The lamp will/may get hot if it is switched on, but not if it is switched off.
Regardless of which socket it is plugged into, it will only draw 100W.
Leif
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Re: USB charging port
I can't find the article now, but I did read recently about a software attack that could cause a USB device to draw too much current and cause overheating. If I find the article again then I will post a link here.
Edited to add
FOUND IT. BadPower Vulnerability In Fast Chargers Might Make Phones Halt And Catch Fire
Edited to add
FOUND IT. BadPower Vulnerability In Fast Chargers Might Make Phones Halt And Catch Fire
StuartR
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Re: USB charging port
Hi Stuart.StuartR wrote: ↑22 Jul 2020, 21:40FOUND IT. BadPower Vulnerability In Fast Chargers Might Make Phones Halt And Catch Fire
I watched the video and noted in the first ten seconds (and then at later points), a pixel-blurring of the area near the demonstrator's hands, especially as he was plugging in/out the cables - but not while the cable/devices were in place.
This pixel-blurring is similar to news agencies blurring people's faces.
Any idea why this blurring is done here?
Thanks
Chris
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Re: USB charging port
I have no idea Chris. Maybe to hide information about what devices are vulnerable
StuartR
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Re: USB charging port
You fiend Stuart, it took me half an hour to get off that siteStuartR wrote: ↑22 Jul 2020, 21:40FOUND IT. BadPower Vulnerability In Fast Chargers Might Make Phones Halt And Catch Fire
John
“Always trust a microbiologist because they have the best chance of predicting when the world will end”
― Teddie O. Rahube
“Always trust a microbiologist because they have the best chance of predicting when the world will end”
― Teddie O. Rahube
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Re: USB charging port
jonwallace wrote: ↑23 Jul 2020, 14:42You fiend Stuart, it took me half an hour to get off that site
StuartR
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Re: USB charging port
He who plants a seed, plants life.
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Re: USB charging port
I think I would actually need 3.0 capability fitted internally on my optic/brain interface to comprehend everything in 3 minutesChrisGreaves wrote: ↑23 Jul 2020, 15:23Well, Jon, if you had used 3.0 technology you would have been done in three minutes!
Cheers
Chris
John
“Always trust a microbiologist because they have the best chance of predicting when the world will end”
― Teddie O. Rahube
“Always trust a microbiologist because they have the best chance of predicting when the world will end”
― Teddie O. Rahube