Output current of Firewire?

[limpport]

I've been searching Google with no avail. I've found voltages, but nothing about current. Anyone know off the top of their head? Specifically, it's the firewire port on an early 2009 Macbook.

[bicostp]

Well, according to Wikipedia:

The 6-circuit powered connector, now referred to as an alpha connector, adds power output to support external devices. Typically a device can pull about 7 to 8 watts from the port; however, the voltage varies significantly from different devices.[19] Voltage is specified as unregulated and should nominally be about 25 volts (range 24 to 30). Apple's implementation on laptops is typically related to battery power and can be as low as 9 V and more likely about 12 V.[19]

So let's say 5 watts at 25 volts, or about .2 amps, according to the Ohm's Law calculator I found online.

[lifeisbetterwithketchup]

[limpport]

I'm making a USB hotplate from Instructables Dead Computer Contest. However, I'm using an old Pentium 133MHz processor. It gets slightly warm with USB, and I'm wondering if Fire-Wire can make it hot to the touch.

[vskid]

USB shouldn't provide more than 2.5w, so if bic's info is correct, Firewire should give you about 3 times as much power.