1394 PCIe Watt/Power usage

Hello,

I would like to ask if anyone could tell me how much power or how many watts is needed by a 1394 PCIe Firewire card. I am thinking of installing one in my desktop because I want to transfer videos from my old camcorder, but I'm not sure if my computer can handle the extra power that it will need to put out for the firewire card. I've tried searching for an answer on the net but have not found one. My desktop is as follows:

CPU: i3-2120 @ 3.3 ghz
GPU: Power Color HD 6850
MoBo: ASUS P8H61-M LX PLUS REV 3.0
RAM: 8 GB Corsair Dominator PC3-10666 1333 mHz 240-pin DDR3
HDD: 500 GB Western Digital Caviar Blue SATA III 7200 rpm
PSU: Cooler Master eXtreme Power Plus Series 500W
Case: Hercules ATX mid Tower
Optical Drive: Asus 24xDVD-RW
OS: Windows 7 Ultimate x64 bit
Generic Mouse and keyboard

Any input would be greatly appreciated. Thanks.