Quote: Originally Posted by
HiJackZX1 
I have 2 hubs that are powered with DC-DC adapters, but I was not sure how to connect them. I was worried that if I connected them to my relay, they would loose power before the PC could shut down or hibernate. So I decided to add them to the 12v rail on my OPUS 320. Was this a wise idea?
since you USB hubs run on 5VDC, you can power them directly from the OPUS +5V rail (instead of running two 12vdc-5vdc PSUs off the OPUS +12V rail). modern systems don't pull much from the +5V rail, so chances are you have enough unused power for your hub(s).
yes, if you power the hubs from the main relay, power to the hubs will be cut before the PC shuts down. the solution to this is to run a second relay for the hubs, with the OPUS +12V rail as the coil power. (see diagram below);
