Now see what happens when I haven't had my coffee
Yes, active cooling includes a fan and heatsink.
And Yes, there are completely closed PSUs out there (some only have vents), they don't need much/any ventilation, because they use higher rated components that just don't get hot at all. More expensive, but cool (pun intended). I have yet to see one for a PC, but have used several in labs. It must be cheaper to slap a 5$ fan in a PSU than to upgrade the whole circuit, so I guess that's why most of us have these hot supplies (no pun intended).
FYI, I've seen a 250W supply where the fan died, and it ran just fine. (but it had two brown spots on top
)
What I know about the 15krpm HDs is that they are server drives, which implies that it will be well ventilated. (so I wasn't completely asleep!). I have no doubt that yours reaches 70C, but I also have no doubt that this is normal. Now if someone encases the thing in foam... that could become a problem.
You are right about extending the MOSFETs though, and it is a good idea. It would certainly work quite well, and not cause any problems, as long as (like you said) the lead extensions are thick enough.
I've also got to figure out how to slap together an inexpensive (but variable) PS for 2 * 226W Pelts, and a small (?!?) 80W one, at 12V. Any suggestions? I'd rather build it myself than slap a bunch of PSUs together...
I'll search for your article.