Are the diodes necessary?
Posted by: monkey ()
Date: May 30, 2009 01:30PM
I've been running my dual 500 Gig-E on a Aopen 250w psu I had lying around. I mad emy own adapter 3 years ago, before finding this site. I used a 20-24 pin adapter and wired it up with the 5vsb going straight into the trickle 28v line. I haven't had any sleep or other issues in the 3 years it's been running. The only firewire devices I have are hard drives which have there own external power supplies. They work perfectly as well. I also have a few firewire pci cards lying around that I could use in case I needed firewire ports to power a device. The Pci cards have a molex input on them, so they would get there 12v directly fromt he 12v line on the power supply.
I wonder if the voltage drop from the diode on the 12v driving the firewire port could cause the weird firewire problems people had with their Maxtor Apple rom hard drives. Also if you had a power supply that was supplying slightly less than 5vsb, and then you added a diode to the mix, the drop might result in too little power to wake the system form sleep, resulting in sleep issues. Just my 2 cents.