power and cooling

[lukeg01]

hello
i'm planning to buy a raspberry and wish some info:
is it possible to connect a powerd hub for more ports and power it using the hub ( without fringing my system)
and wish cooling block material is the best ( if you search on ebay you find mostly aluminium and copper) if somewane can tell me if they are use full
i'm planning to have it on all time and the board i wish to buy is the B rev 2.0

luke
(see attachment for power schedule)

[gmc]

If you are going to connect a few devices to the Pi then you will have to use a usb powered hub. The pi doesnt provide enough power by itself to power a few devices. The pi is also very fussy when it comes to usb devices - have a look here:

http://elinux.org/RPi_Powered_USB_Hubs

For heatsinks - I have read a few threads on the advise of using them or not. Some people say you dont get much benefit from them, but as they are so cheap it doesn't harm putting them on, especially if you are going to OC your pi. And it looks cool

http://www.raspberrypi.org/phpBB3/viewtopic.php?t=26156

Either copper or Alu will be fine I reckon - I have 3 alu ones.

[mahjongg]

if you use a hub that outputs 5V on its input (square) port, (as many hubs do) you "backpower" the PI, and you don't need to power it through the micro-USB port. The disadvantage of this is that you bypass the polyfuse in the PI, so it isn't protected anymore against shorts, and over voltages.
A heatsink is never needed on a PI.

[Gordan3D]

In Relation to the back-powering.

If I alter the USB cord and remove the power line, will this remove the back powering?

[W. H. Heydt]

In Relation to the back-powering.

If I alter the USB cord and remove the power line, will this remove the back powering?

Yes.

Or you could get a hub that behaves correctly and doesn't feed power back through its uplink port. It'll likely cost more, though.