I was wondering for a long period that why don’t they do the standard for the power supply and put only 12V or something as the same standard as the A AA AAA or C or D battery do at 1.5 V.
I think that using only one power source may easier to plan in the long run, more than to think about what the psu will be.
Now thank to google that show me what it must be for the server they shown.
So now we knew that 12 V for everything possible, even with the hugh amount of process.
