Electronics > Beginners
Linking PC PSUs for a dual rig build.
<< < (3/6) > >>
Twoflower:
One way or the other you need to run cables 'between' the main PSUs to identify that which ones are powered. And installing a third PSU does not make the installation easier as you have less space and more cables. Especially you need to mount it somewhere in the case which has only two positions, hasn't it? But that is your decision.

Nice cable management.  :-+

I wonder what would require a 1.2kW PSU. My guess would be a 18 core Xeon with 3x Titan-V, 64GB Ram, 8HDDs. For the fourth GPU it's slightly exceeding the 1.2kW. Or a smaller CPU with a TDP of 90W with 4x Titan-V and few less HDDs.
Crysis1982:
Not that intense.
Just a 7820X @ 4.7Ghz, two 1080Tis @ 2.1Ghz, two Lang D5 pumps, 15 120mm fans, 4 2TB SSHDs, 2 SSDs and 4 RGB strips.

Plus it was 20% off at PCCG last year.
Eka:
12 VDC with non critical voltages for running the pumps and fans. Use diodes. The fans, and pumps will see 11 VDC, but will still run, but likely a bit slower. The diodes can be mounted to a plate of aluminum to heat sink them, but isolate them from the heat sink if they have cases that are live.

As for connecting the grounds. Because of the isolation in the power supplies, that is a non issue unless the site has badly messed up wiring with power from two transformers going to the same outlet and don't have properly earth grounds. Even then they likely share an earth ground so it is still a non issue.

My question is with the third power supply. What happens if the third power supply doesn't come on, or fails during use? Can your system automatically deal with that without cooking a CPU? Both the diode and relay methods allow the fans to continue to be powered with a power supply failure. Diodes have the advantage of being more reliable, but the disadvantage of the voltage drop. Relays can have contacts weld. Even at 12 VDC.
Crysis1982:
Hopefully I will notice all the fans and pumps not working and turn off the system. There should be enough thermal headroom with the 4 480mm rads to remove the heat before I shut it down.

I think I have found a solution using a pre-made PCB and PSU linking cables to make it work. It should allow the two main PSUs to jump start the third using the 24 pin. Then all I am using the peripheral connections to run miles and data cables.
wraper:
Just use 2 Schottky diodes (or dual diode) at positive power rail. Thus it will be powered from whatever has higher voltage. GND is common through the case but you could put a wire for lower resistance. And WTF you would need a third PSU? Consumption is way too low to justify it.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod