After a few issues with 4TB 2.5" hard drives, and external USB disks, I'd like to use a 3.5" drive, but the NUC's internal SATA power connector does not support this (doesn't provide 12V).
I'm considering an aluminium case (Hammond diecast enclosure, 1590DBK, 187x119x56mm), that's screwed on to the Intel NUC's 2 mounting holes, with a larger hole in the base to route the power, data cables, and maybe allow some air flow.
For power, could I run a wire off the 19V power supply (internal), in a safe way to power a 4TB Western Digital Red hard drive (WD40EFRX), which needs a 5V and 12V supply, 1.75 amperes (peak), at 4.5 watts.
Maybe using two linear voltage regulators to provide 5V and 12V (e.g. L78S05CV and L78S12CV)?
These can accept an input up to 35V, current up to 2 amperes, and have a thermal resistance of 5 °C/W junction-case or 50 °C/W junction-ambient.
Or, as per @bimpelrekkie's suggestion, a fixed switching regulator (e.g. LM2596T-12 and LM2596T-5.0.
But I'm not sure:
Would this be appropriate for a hard drive? Can it provide a clean enough power supply, and keep running for a long period of time (4+ years).
Would it produce too much heat? I'm considering getting some 20x15x10mm heatsinks, with 3M screws, for the 3.75mm hole.
Is there a good way to connect them to the aluminium case, assuming a heatsink? I don't think solder works, or thermal tape would hold well enough, so maybe an epoxy that can also handle high temperatures (just to be sure.)
Will the 90W power supply be happy with the extra load? The computer currently uses 25W while running both of the CPU cores at 100%.
Where I'd connect the 19V supply to the 12V regulator first, should the 5V regulator connect to the 12V (so there is less of a drop from 12V to 5V, maybe helping with heat/life,) or should I connect it directly to 19V (so there is less current being pulled though the 12v regulator?) i.e. series or parallel?
Is there another way of doing this? Maybe two DC-DC step down buck converters? I've never used these before, they do look interesting, but I don't know how reliable they are.
And is there anything else I should consider with this setup?
Previously I've used a separate power supply, with an external USB hard drive, but this has introduced 2 extra wires, and where this computer will be in an office 4+ hours away, I don't want to do that journey because one of the cables have "fallen out" (at least if the computer only has 1 cable, I can get someone non-technical to check it).