any fanless AT power supplies?

Hey, there's some pretty quiet solutions for modern PCs. My little 286 needs no fans at all, except the fan in the power supply. Are there any AT fanless power supplies around? I suppose I can use a fanless atx supply with an adapter cable, but those won't fit in an AT case, right?

Next step, I'll replace the hdd with CF. I wanna go silent and solid state on this box.

The fan is there for a reason dont get rid of it.

How about replacing the original fan with a modern version with speed control , I have used some antec fans with a three way switch and on the low speed you can only hear it if you are VERY close to it.

But on my compaq deskpro the fan runs on 110v and I would have to be a bit more creative.

ATX PSU should fit nicely in a "baby AT" case...all you need is one of these: http://www.censuspc.com/product-pr-4257.html

On older supplies like that (unless I want them to be stock) I always put a resistor in line with the fan motor in the PS so they only barely go around. Very little air movement is needed because the PS is only operating at a few watts. Yes, the motors are not made for that, but it works. I'm just looking at the Pentium 1 in front of me which has been on 24/7 for a couple of years now and I see three 22Ω resistors in series. I guess I decided at the time that 66Ω was appropriate, but it varies with motors. Use one watters and you should be fine. I've been doing this for years.

You can also cut the ground wire to the fan and connect it to 5V. With a 12V supply that will give 7V across the fan and quieten it down considerably.

it does work but it's a little bit risky, it does mean that if your fan goes shorted, or the load on the 5v rail goes low, it'll take your 5v rail up. Resistor's the best option, we're running little 12v fans with 100 ohms or so in series, and they still shift quite a bit of air.
Be careful if you decide to temperature probe the heatsinks in the power supply. they're quite often at high voltage.

carangil said:

Are there any AT fanless power supplies around?

Click to expand...

Sure. There were computers made with fanless AT power supplies.
I once made a router out of a 486 board, a floppy with some linux distribution and a fanless PSU.
Had to hunt on auctions for the PSU, but they showed up every few weeks then and again.
And no one ever looks for them so they were to get for next to nothing...

These were no power demons, outputting some 45W or so (can't remember),
but for a silent machine (no spinning drives) it's more than enough.