interconectivity

[XWrench3]

so as i was straightening up this morning, a thought popped into my head. i have an external usb 2.0 7 port hub. that is plugged into the back of my computer, since they are nice to have, but hard to get to just to plug something in for a short time. anyway, because of the large number of ports, and the potential of drawing more power than is available thru the normal plug, it comes with a power supply that also plugs into the hub. so i have 4 questions about this. 1) i theorize that the power from the external supply would be pushed into the computers usb circuit whenever there is power that is not being used by whatever is plugged into the hub. am i correct in this theory? 2) and will any excess power hurt anything inside of my computer? 3) what about when the computer is in sleep mode, or turned off? 4) also, would this power be pushed into the usb 3.0 circuit as well? my thinking on that is that in most likelihood, the power for both systems comes from the same part of the power supply, and would most likely back feed into it. i am not even going to get into the possibility of the motherboard sharing a power source thru the circuits laid out on it. that would be for me to follow the board circuits in a diagram, but i think that would be an exercise in futility if the power going to both systems is shared at the power supply anyway.

 

[carnageX]

No, the hub does not push power into the USB ports. The power adapter for the hub is there to provide additional power to the devices plugged into the hub's ports (which push "out" the ports to power a device, not "into" the hub). The only way power would go into the PC's USB ports is from a lightning strike and the hub was on the affected circuit.

 

[XWrench3]

thanks! i was not really worried, but i was concerned that in the long run i could be causing damage. i knew that electricity can be pushed backwards thru a household circuit breaker, so i figured there could be a chance of it happening thru that circuit. the only way to know short of taking an electrical engineering course is to ask. asking is a lot less expensive, and a lot faster!

 

[PP Mguire]

Yea these plugs are there to provide enough current for the extra devices being plugged into one port or things like external drives. Definitely something needed if you intend on using more than 3 ports at a time.