Does anybody know of any good, stable AT power supplies with good build quality? I am putting together a retro 386 gaming machine and want to find a quality AT power supply.
My personal recommendation would be either to find a good used/NOS one (Delta, SeaSonic, etc) or get an ATX to AT adaptor(if you do this make sure the ATX PSU you use has a strong 5v rail since it is the most heavily used by an older system). Most of the new AT PSUs currently available are gutless wonders.
The 386/486 machines will most likely still use -5v, -12v (afaik one of these was used on ISA slots) which are no longer available on ATX power supplies.
So the ATX to AT cable won't do much good.
You're going to have to pick an AT power supply or an old ATX 1.3-1.4 power supply... the cheap kinds on Newegg that still say Pentium IV on them. But basically look for -5v and -12v on the label.
The requirement for power supplies to provide -5v was made optional around ATX 2.1 so anything older than that should still have it.
The 386/486 machines will most likely still use -5v, -12v (afaik one of these was used on ISA slots) which are no longer available on ATX power supplies.
So the ATX to AT cable won't do much good.
You're going to have to pick an AT power supply or an old ATX 1.3-1.4 power supply... the cheap kinds on Newegg that still say Pentium IV on them. But basically look for -5v and -12v on the label.
The requirement for power supplies to provide -5v was made optional around ATX 2.1 so anything older than that should still have it.
I forgot to mention that info in my post, thanks for putting it up.
This would be an excellent candidate for use as an AT PSU: TOPOWER ZU-500W 500W = $35
It has -12v and -5v rails and a strong (46A) 5v rail. TOPOWER is not the best PSU around but they relatively decent and are better than most PSUs out there that still have -5v and -12v rails.
I forgot to mention that info in my post, thanks for putting it up.
This would be an excellent candidate for use as an AT PSU: TOPOWER ZU-500W 500W = $35
It has -12v and -5v rails and a strong (46A) 5v rail. TOPOWER is not the best PSU around but they relatively decent and are better than most PSUs out there that still have -5v and -12v rails.
I've got the 450W of this (excepted it's branded Zumax instead of Topower) and it's got Fuhjyyu caps in it...
don't buy it.
I've got the 450W of this (excepted it's branded Zumax instead of Topower) and it's got Fuhjyyu caps in it...
don't buy it.
That's the thing about TOPOWERs they tend to be decently built PSUs but have junk caps. However most of the other PSUs in current production that still have -12v and -5v rails are both poorly built and have junk caps, so that TOPOWER is probably one of the better options for a brand new current production PSU(especially after a recap) even with junk capacitors it will probably last a couple years, a NOS PSU would probably be the best option if he can find a decent one that isn't hideously expensive(the fact that good NOS 200w-250w AT PSUs are going for $50+ on EBAY is nuts, case of extremely limited supply I guess).
I've got the 450W of this (excepted it's branded Zumax instead of Topower) and it's got Fuhjyyu caps in it...
don't buy it.
well, if the guts were ok, one could buy it, use it long enough to make sure it works, and then do a recap.
there is a user here called brethin who IIRC has a few old AT psus he is looking to get rid of... he may have scrapped them already though.
off topic:
if they still exist, that reminds me, I have a really nice AT case that lost it's PSU due being a gutless wonder (CHICAGO PSUs= )... too bad the board was the PC-CHIPS 386 cacheless board of doom and I have no extra sdram for my pII/PIII AT board... maybe I should put the case up for "adoption"...
Athena is OK, they make a lot of server stuff (not saying its good server stuff)
those AT units are death traps.
the worst modern gutless wonders I have seen were athena AT units. as in small heatsinks, 4 diodes, few/no filter caps, no input filtering, thin wire, bad fans, etc.
they make powmax look good.
hell, they make echo star look good!
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look at the pics. look how thin the wires are.
do yourself a favor and buy a used hipro or delta or the like...
Again... you need the power supply to deliver -12v and possibly -5v as well if it's an old motherboard.
The adapter cable simply assumes the ATX power supply will deliver these voltages on some pins, but starting with some versions of the ATX standard those voltages were made optional and later they were removed completely.
The pins still exist in the ATX connector so the adapter will route them where they should go, but new power supplies won't even have a wire going in those spots.
Here's the ATX connectors, both the more recent 2.0+ version and the old 1.0 version:
Note how the -5v wire (white) is present on the old connector (to the right) and it's missing in the new connector ( n/c on new one). The adapter cable needs to have the wire in the left connector to route the -5v to the AT motherboard power input connector:
Don't buy from eBay. You're not saying where you live... so here's assuming you're in US, buy this:
Anyway, for a 386 or 486, they'll be good enough, those machines don't use more than 60-100 watts anyway.
If you're up for a bit of soldering, I guess you could buy a decent power supply with -12v (should still be plenty modern ones) and generate the -5v from the -12v line using a negative voltage regulator.. for example something like this:
You just feed it ground on pin 1, -12v from the power supply through pin 2 and out comes -5v on pin 3 ... which assures the power supply -5v as available even if no components on board will use it.
They are old (NOS) OEM units left over from manufacture and are hard to beat for the money. Both of these units are old enough to still have -12v and -5v rails, plus a strong +5v rail.
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