Is there such a thing as a device that can be plugged into a USB port that will display the voltage and available power, in the same manner that one would test a vehicle battery or wall outlet ?
Thanks for reading and all help is appreciated.
There are such devices. I did a search at Amazon (uk) : usb multi power meter and found a variety of responses.
On a USB port you have 5 volts from the power supply.
USB - Wikipedia
To measure the voltage, you put a voltmeter on Grd and +5 (paralel). That's easy.
To measure the current you must put an ampere meter in series with the load. This is difficult.
To find out the power consumption you must multiply the voltage by the current.
Finally, the available power you don't measure as it's a limited by the devices (power supply and MoBo)
Thanks for the link; one of those might prove handy in my trouble-shooting endeavors.
After reading that line, my old noggin has puzzled out a workable plan of action, involving one of those USB desk lamps (or two or three) and an ammeter; I agree --- it is difficult.
Thanks everyone.
I use this one right here: LED Digital USB Charger Doctor Voltage Current Meter Tester Power Detector LCD 962160709905 | eBay
I wanted to see if I'd get a spike from my Flight Sim yoke as to the very random and not so occurrent PC crash. It happens very rarely and I've had yet to find its source. Not even an event in the logs.
Anyway, there's others too and some more advanced USB power meters. You can even use them with your phone or tablet.
Thanks for the recommendation and link.
The scenario that put me on this quest was an as yet unexplained drop in the current output of my USB 3.0 ports.
My wife and I have exactly identical tower machines, with identical components and extras, with the exception that mine has a CX750 Corsair power unit and hers still has the as-delivered 305-watt unit.
Both machines came originally with only USB 2.0.
I have added 5-port USB 3.0 cards and 4-port front-mounted USB 3.0 hubs with a fast-charge port to both machines.
Up until a couple days ago, I could plug a non-self-powered (soccer-mom type) external HDD (we have at least half-a-dozen of these) into any port, front or rear, 2.0 or 3.0, on either machine, and it would be immediately recognized and could read/write to a fare-the-well.
To add to that, all of the rear ports have six-foot USB 3.0 extension cables, so that I don't have to crawl down in amongst the spider webs to use the ports; I can tell no difference whatsoever in a drive being plugged into the extension cable, as opposed to being direct-connected.
Now, for reasons as yet undetermined, on my machine, there is not enough power on the front 3.0 ports, nor on the extension cables, to allow an ext. HDD to be recognized.
I can plug straight into a rear 3.0 port and it will connect, but not as immediate as it was.
I can still plug into any of the 2.0 ports, front or rear, and all works well.
The weakened connection points still have plenty of power for flash-drives and card-readers.
I plugged in a self-powered 7-port 3.0 hub to one of the USB extension cables and the ext. drives will connect and recognize fine.
So............, my surmisement is that my 5-port USB 3.0 card has weakened power output; it still has barely enough power to operate the drives when direct-connected, but not enough when using the front ports or the extension cables.
Before this malady occurred, I could have several of these drives connected at the same time and copy from one to another without a hitch.
Sorry for such a long-winded explanation.
Maybe the USB 3.0 card is going bad.
You should be able to view amp draw from a USB device under device manager.
I finally got around to ordering one of those.
I had no idea that the wife was an ice-cube USB-charger hoarder; I started testing chargers and she just kept digging them out.
One of these would have been handy ages ago and I highly recommend them.
As to my front USB panel losing power output, I found the culprit when I was installing a PCI SATA card; the power cable to the USB panel is just long enough and there are a ton of wires in my machine; the last time I had the side-panel off, I must have pushed the mess of wires a bit too much and had almost completely disconnected the power connection to the USB panel.
I added a 8-inch extender to provide a bit of slack; and, everything is back up and running; the USB ports have plenty of power now.
One thing I did find curious while poking my shiny new little tester into various USB orifices: I was using a USB dual camera battery charger to provide an amp load during my tests, I have a Pluggable self-powered 7-port USB hub that has both outer ports designated as hi-load charging ports; I was expecting the two designated charging ports to read somewhat higher amperage than the regular ports --- not so, all seven ports read the same = 5.24-volts 1.57-amps
Keep in mind that's amp draw for the device connected to the USB power meter. Not amp availability from the hub.
What is the make and model of the hub?
1.57 amps is pretty decent on draw and that tells me the hub is at least pumping that out. On the hub should read how many amps it can provide.
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