Re: usb question

"Twayne" <nobody@xxxxxxxxxxxxxxxxxxx> wrote:

Since the specs are a total of 500 mA,

The USB low power bus mode specifies a maximum of 100 ma per port.

However, if you have two hard drives that want to suck 250 mA...

USB powered drives stay within the 100 ma per port requirement. If
they draw more than the 100 ma limit they supply a two port cable and
suck power from 2 ports.

EVER device has a power requirement of xxx mA at xx
volts. Exceed those specs, and the device will no longer receive power,
along with any others attached to the same controller.

A correctly designed computer will be able to supply 100 ma to each
USB port. A correctly designed USB powered drive will draw no more
than 100 ma from each USB port. No problems no matter how many ports
involved. Not a hard concept to understand.

It's not even close to rocket science,

I would agree.

You boys can have the last word...
.

Relevant Pages

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