Passive USB Hub

[PezCuckow]

Hi all,

I just wanted to confirm before I buy a passive USB hub, that it will work with the Raspberry Pi if the item being plugged in by USB is powered.

I'm hoping to plug two mains powered USB hard drives into the same USB socket on the Pi as the other socket is being used for a USB printer.

I'd prefer a passive USB hub to save another device from being plugged into the wall, which seems a bit wasteful!

Can you confirm that a mains powered hard disk wouldn't draw much (or any) power from the USB so a hub would work?

Thanks,

Pez

P.s. I have searched the forum, but couldn't find a detailed post on passive USB hubs, usually the response is: just buy a powered one.

[Davespice]

Hi there!

Can you confirm that a mains powered hard disk wouldn't draw much (or any) power from the USB so a hub would work?

This is something you should ask the company that makes the disk you're using.
However I would assume that it wouldn't need to draw much power at all if it has its own power supply.
There is a list of verified Pi peripherals here; http://elinux.org/RPi_VerifiedPeripherals

[cosmicnut]

As long as the drives are mains powered then you are OK to use a passive hub.
Its really only bus powered drives that need a powered hub.

[boyoh]

It is handy to know the difference between a passive Hub & Active Hub

A Passive hub drawers power from the Pi power supply ,This will divert
Power from the Pi to drive the signal. If you have several thing plugged
In to your hub the current needed to drive the signals will accumulate.
Diverting to much current from the Pi will not allow the Pi to function
Properly.

A Active hub have built in Buffer stages, this will allow the Pi signals
To draw the drive current from the active hub power supply
And not draining the Pi power

All signals require power High or Low to drive them throe the input resistance they will meet

Advice Use A powered Hub