USB Power

USB ports capabilities
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fransor
Posts: 3
Joined: Thu Aug 27, 2009 7:37 pm

USB Power

Post by fransor »

How much current can I take out from the USB ports? Is there any different at the ports in the front/rear?

Thax in adv.

irads

Re: USB Power

Post by irads »

You should be able to draw 0.5A per port.
Rear ports are reported to be marginally more tolerant to higher current draw.

Paul T
Posts: 2
Joined: Fri Sep 02, 2011 8:58 am

Re: USB Power

Post by Paul T »

Hi

I need to pull 0.5A from two ports, run a touchscreen monitor on a 3rd. For power usage - do I add all of these requirements to the nominal 10W power use of the CPU. Also with so much current being drawn - should I run my 2 x 0.5A devices off a separate 5V supply (I have the option)

Thanks

irads

Re: USB Power

Post by irads »

Total current consumption from all USB ports should not exceed 1.5A.
So if you have the option to power the devices from an external source it is recommended.

nvd
Posts: 1
Joined: Tue Jan 24, 2012 4:43 pm

Re: USB Power

Post by nvd »

Regarding the limit on the current draw (1.5 A) through all the USB ports, is there any overall protection? As I read somewhere, each USB has a current limiter of 500 mA but that translates to 2 A of collective draw from 4 USB ports (FitPC2).

I am a bit concerned as two MIMO Touch 2 screens are powered by 4 USB ports. According the MIMO specs, each screen draws from 0.6 A to 1 A; 1.2 A to 2 A for two screens. The shipped supply of FitPC2 could not handle this current draw and thus I replaced that with another 12 V power adaptor (5 A).

Things are working fine now and PC is not freezing. Is it safe to do this way? Am I stressing the supply of FitPC2 that may lead to premature failure?

gabrielh
Site Admin
Posts: 1260
Joined: Thu Jun 02, 2011 1:13 pm

Re: USB Power

Post by gabrielh »

The FitPC2 designed with a safety margins for an overcurrent situation, but operating in such mode highly unrecommended and may lead to a faster hardware wear, so I recommend to use an external power source on your setup.
Gabriel Heifets

Fit-PC2/3/IntensePC support.

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